Welcome to TiddlyWiki created by Jeremy Ruston; Copyright © 2004-2007 Jeremy Ruston, Copyright © 2007-2011 UnaMesa Association
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A traditional class meeting on campus naturally allows for regular communication. This is beneficial by helping students better understand the material along with allowing the instructor to more easily gauge how everyone is doing in the class.
I would like to ensure hosting most of this course online does not deprive us of regular communication. Class participation will be worth 10% of your overall grade. Each week's class participation will be worth ''50 points'' total. Multiple posts each week will be necessary to receive full credit.
Posts for each week must be made by Sunday, 11:55 p.m. (EST) the following week in order to receive full credit. This allows one week to post questions about outstanding assignments and one week to post questions about labs after they have been returned. Organization is important - __please post lab questions on the discussion board for the week they were assigned__.
Joining our on-campus meetings and group Zoom meetings will also earn class participation credit.
!! Participation:
You may ask questions, work collaboratively on assignments, and provide assistance to one another in Discord. You can also provide ideas or helpful resources that assisted you on your assignments. Credit may also be received for joining or participating in either regularly scheduled or ad-hoc group Zoom meetings.
!! Rubric for weekly class participation:
* 25 points - Actively participate in a group Zoom meeting
* 10-20 points - High quality posts which contain well-developed questions, actionable suggestions, or recommendations
* 15 points - Attend a group Zoom meeting
* 5-10 points - General comments regarding the assignments. No specific insights directly related to the problem or responses to questions which are not actionable.
!! Quality of Remarks:
You will be evaluated based on the quality of your participation by asking questions, providing constructive assistance, making recommendations related to our material, and making pertinent comments.
The discussion forum and Zoom meetings are a valuable component of learning since they allow you to see a variety of solutions and ideas just like you would in a classroom.
Generally, please do not post direct solutions to lab questions, especially unsolicited, before their due date. Doing so will not be awarded participation points. If someone is genuinely stuck on a problem and you'd like to help, guidance towards the solution is always a more beneficial place to start rather then just posting the answer. If you just post the answer, I cannot tell if someone understands the problem or simply copied your solution.
Please be sure to check out the [[Using Discord]] page to see more useful information.
!! Adding New Threads
Good organization is important. Create new threads in the weekly Discord channels in which the material was assigned. When naming your threads, use something descriptive in the name and not just the lab and question number. The highlighted thread is a model to follow and will make things easier to find as the number of posts grows. Be sure to scan for an existing thread relating to your topic before creating a new one. Usability is an important consideration in what you do. ''Not using descriptive thread titles is detrimental to usability, so that post will not receive full credit.''
[img[img/discussionBoards.png]]
(yes, this screenshot is from Blackboard, but the point still stands. The [[Using Discord]] page has more detail about Discord threads.)
Our class utilizes a [[DigitalOcean|https://www.digitalocean.com/products/droplets/]] droplet for the first half and a [[Hetzner bare-metal auction|https://www.hetzner.com/sb?ram_from=8&ram_to=10&ssd=true&cpu_from=8000&cpu_to=30000&price_from=50&price_to=90&search=Xeon+E5]] server to support the student lab environment during the second half of the semester.
!! ~DigitalOcean droplet
Our needs are very minimal for the first half of the semester; we only require a Linux shell server everyone can access to practice the commands and submit their work. ~CentOS is used as our Linux distribution.
A $5 per month ~DigitalOcean droplet (virtual machine) is more than enough. ~DigitalOcean droplets are great for small projects like this. We'll use it for two months then take a snapshot and destroy the droplet to save money. It'll then be brought back from the snapshot when it's needed again for the next semester.
!! Hetzner Bare-metal
About halfway through the semester we'll switch from being Unix users to administrators. Each student will be given a small collection of virtual machines to install and configure. Additional resources are required for this portion of the class since each student will require about 6 ~VMs. Instead of just a single VM to cover the entire class, we'll now need a full server. Hetzner auction servers have been a reliable, low-cost option for such short-term needs.
To provide enough resources for the entire class, I'll be looking for a server with the following minimum specs:
* 64gb RAM
* CPU with at least 6 cores at 3.4GHz. I'm currently using the ~E5-1650V2.
* 2x 256gb SSD (SSD drives are important for disk speeds. SATA are too slow)
A server with these specs comes to about 60,00 € per month. We'll need it for 2 months. The total infrastructure cost for this class per-semester is then about $150.
The server is initially provisioned by Hetzner with Debian Linux and [[Proxmox|https://www.proxmox.com/en/]] is then installed to act as our hypervisor. Proxmox runs on Debian and can either be installed from [[its own CD image|https://www.proxmox.com/en/downloads]] or the [[packages can be installed on an existing Debian system|https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_Buster]]. We'll use the latter option here since Hetzner must install the original OS for us and they do not have an option for Proxmox.
After the Hetzner server and Proxmox are installed, ~VMs will be created for our class shell server and for internal monitoring. The class shell server will then be migrated from ~DigitalOcean. Student ~VMs will be created from templates.
At the end of the semester everyone will be given the option to download their ~VMs for use locally with ~VirtualBox. Student ~VMs will then be deleted, administrative ~VMs will be backed up to ~BackBlaze B2 storage for next time, then the server contract will be ended.
Other tools/services used:
* [[Fossil source code manager|https://fossil-scm.org/home/doc/trunk/www/index.wiki]] - Used to handle revision control for server configuration files and scripts
* [[SaltStack Infrastructure management|https://docs.saltproject.io/en/latest/]] - Used to orchestrate VM templates and manage infrastructure monitoring
* [[Naemon monitoring suite|https://www.naemon.org/]] - Used to monitor student ~VMs and provide feedback on completed/outstanding tasks
* [[Docker containerization|https://www.docker.com/]] - Used to rapidly deploy and isolate different services on the same VM in a way that can be easily repeated.
* [[BackBlaze B2 cloud storage|https://www.backblaze.com/b2/cloud-storage.html]] - Used to store management ~VMs and VM templates between semesters. Storage here costs $0.005 per Gb.
The combination of these tools allow for the Hetzner server to be quickly brought online when needed for the new semester, it's ~VMs and templates downloaded from ~BackBlaze B2 storage, and made ready to support our class.
Useful concepts:
* [[Infrastructure as code|https://en.wikipedia.org/wiki/Infrastructure_as_code]] - Rapidly provision servers, ~VMs, and Docker containers for individual services using ~APIs & orchestration tools with pre-made definition files instead of manually. Using this concept, our class lab server is brought up from bare metal to fully online and ready to support users in about 30 minutes with just a handful of commands.
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! Material
!! Watch:
* Difference between virtual machines and containers: https://www.youtube.com/watch?v=cjXI-yxqGTI
* Brief Docker intro: https://www.youtube.com/watch?v=_dfLOzuIg2o
! Notes
As servers become more powerful, it is increasing useful to switch from a standard server installation to some form of virtualization. Virtualization allows us to run several separate instances of an operating system, or different operating systems, on the same physical server. Consolidating what would have been separate physical servers into one allows us to save on hardware, electrical and networking resources, and physical space. A reduced hardware footprint is also easier to maintain. This consolidation has allowed for substansial decrease of the phyiscal footprint occupied by modern datacenters. What previously occupied and entire room can be reduced to a single rack.
Virtualization is supporting this class. All of your virtual servers for our material are running on a single large server in a cloud datacenter, along with many other ~VMs for other purposes. When I first took a course similar to this one many years ago, every student was assigned several physical systems to complete our work. This hardware consumed an entire lab and the overhead to maintain the hardware consumed a great deal of our time.
Containers are an alternative to this type of full virtualization, or can be used in addition to it. Containers, as the name implies, contain a set of resources and isolate them from the rest of the system. Instead of a service, like apache, having full access to all resources on the operating system its running on, running Apache within a container will limit its scope to only the resources we decide it should have.
!! Install Docker
Docker is one popular container system, where images are published and can be pulled down for use. The default version of Docker available with ~CentOS is very old. Instead, we going to add an additional yum repository and install the most recent version.
Execute the following commands to install Docker
# {{Command{ yum install -y yum-utils git }}}
# {{Command{ yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo }}}
# {{Command{ yum install docker-ce docker-compose }}}
!! Start the Docker service
# Configure your system to start the docker service on boot
# Start the docker service now
!! Docker examples
After reading the chapter and reviewing the videos posted above, open the https://docker-curriculum.com/ site and work through its examples.
* Perform these steps on your test VM
* create a scratch space within {{File{ /opt/ }}} when you get to the {{Command{ git clone }}} command. This will download files to your VM.
* Stop when you reach //Docker on AWS//
! Assignment
<<tiddler [[Lab X - Containerization with Docker]]>>
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!! Problem Reports:
If you have a problem, please send me a report I can work with. I need details of the problem, what you tried, steps you took to diagnose it, documentation you reviewed, screenshots, logs, etc. If you send me something vague like "//X command doesn't work//" with no supporting details, there may not be much I can do for you and I will wait for you to follow up your message with meaningful information.
The level of assistance I provide will be proportionate to your effort to troubleshoot and supply details. If you do nothing to troubleshoot and send me little information to work with, you should then expect that much effort put into a response.
!! Time management & workload expectations:
SUNY Poly, as well as most others, [[requires 42.5 hours of work per credit hour|https://www.suny.edu/sunypp/documents.cfm?doc_id=168]]. A four-credit course will thus require 170 hours over the course of our 16 week term, or 10.5 hours per week. Going to college full time is effectively a full time job. I will be expecting that time commitment each week.
Waiting until the last minute to complete, or even worse, begin, the lab assignments will not be a recipe for success. Review the tasks early so you have plenty of time to research the problems, seek help in the discussion boards, and get up to speed if you are behind on any prerequisite material.
!! Grading:
All course deliverables will be collected as PDF documents. Graded copies of these PDF documents will be returned to you containing my annotations. If you have questions regarding your grade or my comments, please contact me via email.
My grading is more traditional. Meeting the bare minimum does not yield an A. A high grade will require intellectual curiosity, problem-solving abilities, thorough responses, and good presentation. Meeting the minimum requirements with standard quality will result in a ''B''. An ''A'' grade is reserved for exceptional work.
Letter grades will be assigned as follows:
| !Percent | !Grade |
| 95% ≥ | A |
| 90% ≥ | A- |
| 87% ≥ | B+ |
| 84% ≥ | B |
| 79% ≥ | B- |
| 77% ≥ | C+ |
| 74% ≥ | C |
| 69% ≥ | C- |
| 67% ≥ | D+ |
| 63% ≥ | D |
| ≤ 62% | F |
!CS 307 Course Notes
[[Getting Started|Week 0]] - Administrative Tasks & course intro
Jan 21 [[Week 1, Part 1]] - UNIX introduction
Jan 23 [[Week 1, Part 2]] - Working with commands, Finding information
Jan 27 [[Week 2, Part 1]] - ''Onsite:'' The filesystem
Jan 29 [[Week 2, Part 2]] - Filesystem, continued
Feb 3 [[Week 3, Part 1]] - Working with files & directories
Feb 5 [[Week 3, Part 2]] - File Globbing
Feb 10 [[Week 4, Part 1]] - File Globbing 2
Feb 12 [[Week 4, Part 2]] - Links & Shell documentation
Feb 17 [[Week 5, Part 1]] - File Permissions
Feb 19 [[Week 5, Part 2]] - Streams & Redirection, Introduction to filters
Feb 24 [[Week 6, Part 1]] - ''Onsite:'' Review & Working with Filters
Feb 26 [[Week 6, Part 2]] - Filters Continued (grep, sort, uniq, strings)
Mar 3 [[Week 7, Part 1]] - Filter Continued (tr, sed, awk)
Mar 5 [[Week 7, Part 2]] - I/O practice & Quoting
March 10 - 14 : Spring Break!
Mar 17 [[Week 8, Part 1]] - Process management & Job control
Mar 19 [[Week 8, Part 2]] - Regular Expression intro
Mar 24 [[Week 9, Part 1]] - ''Onsite:'' More Regular Expressions
Mar 26 [[Week 9, Part 2]] -
Mar 31 [[Week 10, Part 1]] -
Apr 2 [[Week 10, Part 2]] -
Apr 7 [[Week 11, Part 1]] - Working with the shell - Variables, Substitution, Quoting, History
Apr 9 [[Week 11, Part 2]] - The vi editor
Apr 14 [[Week 12, Part 1]] - More vi & more sed
Apr 16 [[Week 12, Part 2]] - Shell Scripting Intro
Apr 21 [[Week 13, Part 1]] - Shell Scripting
Apr 23 [[Week 13, Part 2]] - Version Control
Apr 28 [[Week 14, Part 1]] - Shell Scripting 2
Apr 30 [[Week 14, Part 2]] - Shell Scripting 3
Mon, May 5 @ 6:30pm - Final Exam in C012
/%
tar, compression & working with collections of files
Finding files
Working with the shell - Variables, Substitution, Quoting, History, Aliases, metacharacters
Streams & Redirection, Introduction to filters
- ''Onsite:'' Shell metacharacter quiz. Filters: cat, head, tail, grep, tr, cut, sort, uniq, strings, sed
finish filters, catch up
Finding files, Process management & Job control
''Onsite:'' Regular Expressions
More regular expressions
Mar 24 - The vi editor
Mar 26 - More vi & more sed
Mar 31 - Review labs & Review for test 2
Apr 2 - Test 2
Apr 7 - Review test 2, introduce awk
Apr 9 - awk, basic shell scripting, system information
Apr 14 - More shell scripting
Apr 16 - Shell scripting review / Test 3 distributed
Apr 21 - Shell scripting
Apr 23 - tar, compression & working with collections of files. Working with the X server, communication / Test 3 due
Apr 25 - Review for final
Apr 30 -
%/
!!! Agendas for pages in italics are tentative
[img[https://www.cs307.net/img/1x1.png]]
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To use, add {{{[[Styles HorizontalMainMenu]]}}} to your StyleSheet tiddler, or you can just paste the CSS in directly. See also HorizontalMainMenu and PageTemplate.
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!! [[Lab 60 - Scheduled Tasks]]
Assigned [[Week 13, Part 1]]
!!! SSL Certificate renewal
Our lab web server SSL certificate will expire in 90 days. This isn't much of an issue for us because class will have ended and this server will be decommissioned by then.
But if we were doing this for real, renewing that SSL certificate would be a task we would need to account for. SSL certificates created with the {{Command{acme.sh}}} tool can be renewed by running the command with the {{Monospaced{--cron}}} option. Any certs in its configuration will be checked for upcoming expiration and automatically renewed if they are about to expire.
We don't want to worry about running this manually and potentially forgetting about it. We can instead use cron to run this command for us at a set interval.
!!! Cron:
Create the following cron task on your www VM:
* Schedule {{Command{acme.sh --cron}}} to run every other day at 6pm.
* Save your scheduled job to the file {{File{/etc/cron.d/acme}}}
Also complete and submit the [[Lab 60|labs/lab60.pdf]] verification worksheet. This submitted worksheet will indicate your ~VMs are ready to be evaluated for this lab.
* ''Note:'' Lab 60 is a late addition to the semester, so it's getting a high number.
Mastery of this subject material will only come with practice. To that end, this will be a very hands-on and practical course. Expect graded lab assignments regularly to provide ample practice with the assigned material. Properly completing lab assignments on time is necessary to receive a good grade for this course. Not competing lab assignments at all will likely result in a failing grade.
Any deliverables will be collected for review no sooner than their due date. Late assignments may be accepted, subject to time-dependent grade penalty of up to 50%. Presentation of submitted assignments will also impact grade.
{{Note{''Note:'' It is much better to have correct work submitted late than obviously wrong or incomplete work submitted on time. If you're having trouble with some of the material and need more time, please let me know and we can discuss adjusting due dates. Submitting poor quality work to meet a due date is not a wise professional strategy and will receive harsher grading.}}}
!! Submitting Homework Assignments
Homework assignments are to be uploaded to the class shell server using a file transfer program like ~WinSCP and saved to the directory {{File{/opt/pub/cs307/submit/}}}. I will then grade/annotate your work and return the files to you for review. Most homework assignments will be PDF forms to complete. Download the lab PDF and open it in [[Acrobat Reader|https://get.adobe.com/reader/]]. ''Be careful using the PDF viewer in your web browser''. Some browsers will not properly save the file and you will upload a blank document. Grades will be posted to the file {{File{.grades.txt}}} in your home directory.
After downloading the PDF assignment and opening the file in [[Acrobat Reader|https://get.adobe.com/reader/]], add your name to the top, fill in your responses, then save & close the file. It would be wise to reopen the PDF in Acrobat Reader to make sure everything saved correctly before uploading to the server. You should be in the habit of verifying your work before submitting it.
Files must be named appropriately so we don't have filename collisions among everyone's uploaded files. Rename your PDF document following this naming convention: {{File{''cs307-lab#-username.pdf''}}}
* replace # with the lab number
* replace username with your campus username
* Example lab file name ready to submit: {{File{cs307-lab1-jdoe2.pdf}}}
Uploaded labs ''must'' contain your name at the top of the document and their file names ''must'' follow this file name format __exactly__ in order to be graded. This includes case - all letters must be lowercase. The Unix operating systems are case sensitive, so {{File{~CS307-lab1-jdoe2.pdf}}} is a different file than {{File{cs307-lab1-jdoe2.pdf}}}. The former would not be accepted for review.
{{Warning{''Warning:'' The Microsoft Windows operating system hides file extensions by default. This is a terrible setting for a security practitioner and should be disabled. A common mistake is to fail to take this into account and upload files with a double extension, such as {{File{cs307-lab1-jdoe2.pdf.pdf}}}. This file would not be named correctly and thus not accepted for review.}}}
!! How to upload your lab assignments:
--A video will be posted here demonstrating the process in the coming days.-- Please let me know if you have trouble figuring this out.
!! Late Penalties
Point penalties for late lab assignments will be assessed as follows:
|!Penalty|!Condition|
| 0 |Sneak it in past the due date but before I grade the labs|
| 10% |Submitted after the batch has been graded|
| 20% |Submitted after graded labs have been returned|
| 30% |Submitted after we've reviewed a lab|
| 40% |Submitted after I've posted a review video or we've held an online meeting to discuss a lab.|
{{Warning{''Note:'' Labs 1 through 25 will not be accepted after the last date to Withdraw from the course unless prior approval is obtained.}}}
!! Common point deductions
!!! {{Command{cat}}} abuse
It is common for new students to abuse the {{Command{cat}}} command and use it unnecessarily with command strings like {{Command{ cat //file// | grep //string// }}}. In this example, the {{Command{grep}}} command will accept a filename argument and should be represented as {{Command{grep //string// //file//}}}. This seems to be a common bad habit to break. Abusing the {{Command{cat}}} command and using it where it provides no value will result in a 10% point penalty per lab.
!! The grading workflow
# You upload a completed lab PDF to {{File{/opt/pub/cs307/submit/}}} on the class shell server
# Every hour a script will collect new lab submissions which are properly named and copy them to the grading queue, {{File{/opt/pub/cs307/queue/}}}.
## An accepted lab will be moved from the {{File{submit/}}} directory to the directory {{File{/opt/pub/cs307/submit/collected/}}}
## Any improperly named files will not be accepted and remain in the {{File{submit/}}} directory for one week. They will then be moved to {{File{/opt/pub/cs307/submit/invalid/}}}
## ''Note:'' The collection script may occasionally be manually executed between the scheduled hourly runs
# The grading queue will be synchronized to my tablet for review.
# Any annotations will be recorded and synchronized back to the shell server, saved to the directory {{File{/opt/pub/cs307/graded/}}}.
# Grades recorded in my gradebook.
# A script will then be executed to move graded labs ready to be returned to your directory within {{File{/opt/pub/cs307/returned/}}}. You may download them from this directory to see their grades and my annotations.
## This script will also update the file {{File{~/.grades.txt}}} in your home directory. This file contains your grades for the semester.
The directories {{File{/opt/pub/cs307/queue/}}} and {{File{/opt/pub/cs307/graded/}}} are staging directories in the workflow pipeline. You can view the contents of these directories but cannot write to them. Your access is only so you can have full visibility on where your labs reside in the workflow.
tl;dr: You upload new labs to {{File{/opt/pub/cs307/submit/}}} and retrieve graded copies from within {{File{/opt/pub/cs307/returned/}}}.
!! Extra Credit Labs
Extra material which was written for other courses or removed from this course is available for extra credit. Extra credit material will be posted to the main page of the class website and their labs will be denoted with a letter in their number, for example Lab A1. Submit these labs as you normally would with the letter portion of the lab number represented in uppercase.
Extra credit labs will be graded on the same 10-point scale as regular labs and will be tracked in their own group. At the end of the semester, 10% of the extra credit group grade will be applied to your final course average. This bonus cannot exceed one minor-level grade boost. For example, a B may become a B+ but cannot become an A-.
Any instance of academic dishonesty will result in loss of eligibility of extra credit.
!![[Lab E2 - Logical Volume Manager]]
Assigned [[Week E]]
Complete the steps in the [[Lab E2 Instructions|labs/labE2-instructions.pdf]] PDF on your files VM to become familiar with the Linux logical volume manager.
Add additional filesystems to your core VM server
* See the last page in the [[Lab E Instructions|labs/labE-instructions.pdf]]
* Complete the [[Lab E2 Deliverable|labs/labE2.pdf]] and submit this PDF to {{File{/opt/pub/ncs205/submit/}}} on the class shell server
This lab will involve restarting your file server VM. Be sure the necessary services are configured to start on boot and ~SELinux and firewalld are properly configured.
| !Character | !Shortcut | !Most Useful |
| ~CTRL-C |Send interrupt signal to a running command (abort)| * |
|~|Clear entered command line text|
| ~CTRL-A |Move cursor to beginning of command line| * |
| ~CTRL-E |Move cursor to end of command line| * |
| ~CTRL-L |Clear Screen; move cursor to top to screen| * |
| ~ALT-B |Move one word backward on command line|
| ~ALT-F |Move one word forward on command line|
| ~CTRL-U |Erase line to left|
| ~CTRL-K |Erase line to the right|
| ~CTRL-W |Erase a word to left on command line| * |
| ~ALT-D |Erase a word to right on command line|
| ~CTRL-Y |Paste previously erased text|
| ~CTRL-D |Send EOF signal, ending input| * |
|~|Erase character under cursor| * |
|~|Log out (when no other text is on the command line)| * |
| ~Shift-INS |Paste clipboard at cursor| * |
| ~Shift-PgUp |Scroll window up|
| ~Shift-PgDn |Scroll window down|
| Tab |Auto-complete command or file name| * |
| Up Arrow |Previous Command| * |
| Down Arrow |Next command| * |
| Page Up |Previous command search| * |
| Page Down |Next command search| * |
{{Note{''Note:'' The above key sequences were listed with uppercase letters for clarity. It is not necessary to also press the shift key.}}}
!! Tab Completion
The tab key will auto-complete commands or file names, pausing when it reaches a decision point.
If I type the letters ''ad'' on the command line and press tab, the shell will autocomplete it to the string ''add'' before it reaches a decision point and cannot proceed without input. If I press tab twice it will then show me the options I have to complete the command:
<<<
[root@shell data]# add
addgnupghome addpart addr2line adduser
<<<
If I press the letter p and then tab again, the shell will know which command I'm looking for and auto-complete the command ''addpart''
The same auto-completion can be used for files. The path to the networking configuration file on Linux systems is rather long. Try this scenario on the class shell server:
* Type {{Command{cat /etc/sysco}}} and press ''tab''. The shell should autocomplete that to {{Command{cat /etc/sysconfig/}}}.
* We're at a decision point since there are many different ways we could proceed. Type: {{Command{netw}}} and press tab. The shell will autocomplete that to {{Command{cat /etc/sysconfig/network}}}.
* Press the {{Command{-}}} key and press tab again. The shell will autocomplete that to {{Command{cat /etc/sysconfig/network-scripts/}}}.
* Type {{Command{ifcfg-eth}}} and press tab twice. We are presented with the available options.
* Type {{Command{0}}} and hit enter to view the network configuration file.
Using tab helped me identify the available files and reduced the amount of letters I needed to type to view the file. It's slow at first, but once you get used to it greatly speeds up the speed and efficiency of using the shell and reduces the amount of information you have to remember.
!! Command recall
The page up and page down keys can be used to scroll through the recently used commands. This isn't universal; the shell needs to be configured to support it, but its supported by most systems out of the box.
If you have a long command string that wasn't used very recently, rather then press the up arrow several times to find it, you can enter the first few letters of that command and then ~Page-Up. The shell will cycle through your recent commands which began with those letters.
For example, a few days ago I ran the command {{Command{fail2ban-client status sshd-root}}} to see how many systems were trying to break into the class shell server. Rather then type out that entire command (or have to remember it), if I enter the first few letters {{Command{fai}}} and then press ~Page-Up, the shell will search backward in my command history and bring me right to it. If I used the up arrow, I'd first have to scroll through the hundreds of commands I may have entered since then.
!! Copy/Paste
In putty and most other terminal emulators, highlighting text with the mouse will copy it to the clipboard. Clicking the right mouse button will paste text from the clipboard into the terminal at the position of the cursor. If you are connecting from a Linux host like Kali instead of Windows, clicking the middle mouse button or scroll wheel will paste text to the terminal. ~Shift-Insert will also paste text from the clipboard into the terminal.
// //''Name:'' Calendar plugin
// //''Version:'' 0.1.0
// //''Author:'' SteveRumsby
// //''Syntax:''
// //<< {{{listTags tag //sort// //prefix//}}} >>
// //''Description:''
// //Generate a list of tiddlers tagged with the given tag.
// //If both //sort// and //prefix// are omitted the list is sorted in increasing order of title, with one tiddler per line.
// //If //sort// is specified the list is sorted in increasing order of the given tiddler property. Possible properties are: title. modified, modifier.
// //If //prefix// is specified the given string is inserted before the tiddler title. The insertion happens before the text is wikified. This can be used to generated bulleted or numbered lists.
// //''Examples:''
// //<< {{{listTags usage}}} >> - generate a plain list of all tiddlers tagged with tag //usage//, sorted by title
// //<< {{{listTags usage modified}}} >> - the same list, with most recently modified tiddlers last
// //<< {{{listTags usage title #}}} >> - generate a numbered list if tiddlers tagged with //usage//, sorted by title
// //''Code section:''
version.extensions.listTags = {major: 0, minor: 1, revision: 0, date: new Date(2005, 6,16)};
config.macros.listTags = {
text: "Hello"
};
config.macros.listTags.handler = function(place,macroName,params)
{
var tagged = store.getTaggedTiddlers(params[0], params[1]);
var string = "";
for(var r=0;r<tagged.length;r++)
{
if(params[2]) string = string + params[2] + " ";
string = string + "[[" + tagged[r].title + "]]\n";
}
wikify(string, place, null, null);
}
<<defaultHome>> [[Notebook]] [[Outline]] [[Calendar]]
<html>
<center>
<video id="my-video" class="video-js" controls preload="auto" width="1572" height="724" poster="" data-setup="{}">
<source src="video/naemon.mp4" type='video/mp4'>
<p class="vjs-no-js">
To view this video please enable JavaScript, and consider upgrading to a web browser that
<a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
</p>
</video>
<script src="https://vjs.zencdn.net/7.8.2/video.min.js"></script>
</center>
</html>
/***
''NestedSlidersPlugin for TiddlyWiki version 1.2.x and 2.0''
^^author: Eric Shulman
source: http://www.TiddlyTools.com/#NestedSlidersPlugin
license: [[Creative Commons Attribution-ShareAlike 2.5 License|http://creativecommons.org/licenses/by-sa/2.5/]]^^
Quickly make any tiddler content into an expandable 'slider' panel, without needing to create a separate tiddler to contain the slider content. Optional syntax allows ''default to open'', ''custom button label/tooltip'' and ''automatic blockquote formatting.''
You can also 'nest' these sliders as deep as you like (see complex nesting example below), so that expandable 'tree-like' hierarchical displays can be created. This is most useful when converting existing in-line text content to create in-line annotations, footnotes, context-sensitive help, or other subordinate information displays.
For more details, please click on a section headline below:
++++!!!!![Configuration]>
Debugging messages for 'lazy sliders' deferred rendering:
<<option chkDebugLazySliderDefer>> show debugging alert when deferring slider rendering
<<option chkDebugLazySliderRender>> show debugging alert when deferred slider is actually rendered
===
++++!!!!![Usage]>
When installed, this plugin adds new wiki syntax for embedding 'slider' panels directly into tiddler content. Use {{{+++}}} and {{{===}}} to delimit the slider content. Additional optional syntax elements let you specify
*default to open
*cookiename
*heading level
*floater (with optional CSS width value)
*mouse auto rollover
*custom label/tooltip/accesskey
*automatic blockquote
*deferred rendering
The complete syntax, using all options, is:
//{{{
++++(cookiename)!!!!!^width^*[label=key|tooltip]>...
content goes here
===
//}}}
where:
* {{{+++}}} (or {{{++++}}}) and {{{===}}}^^
marks the start and end of the slider definition, respectively. When the extra {{{+}}} is used, the slider will be open when initially displayed.^^
* {{{(cookiename)}}}^^
saves the slider opened/closed state, and restores this state whenever the slider is re-rendered.^^
* {{{!}}} through {{{!!!!!}}}^^
displays the slider label using a formatted headline (Hn) style instead of a button/link style^^
* {{{^width^}}} (or just {{{^}}})^^
makes the slider 'float' on top of other content rather than shifting that content downward. 'width' must be a valid CSS value (e.g., "30em", "180px", "50%", etc.). If omitted, the default width is "auto" (i.e., fit to content)^^
* {{{*}}}^^
automatically opens/closes slider on "rollover" as well as when clicked^^
* {{{[label=key|tooltip]}}}^^
uses custom label/tooltip/accesskey. {{{=key}}} and {{{|tooltip}}} are optional. 'key' is must be a ''single letter only''. Default labels/tootips are: ">" (more) and "<" (less), with no default access key assignment.^^
* {{{">"}}} //(without the quotes)//^^
automatically adds blockquote formatting to slider content^^
* {{{"..."}}} //(without the quotes)//^^
defers rendering of closed sliders until the first time they are opened. //Note: deferred rendering may produce unexpected results in some cases. Use with care.//^^
//Note: to make slider definitions easier to read and recognize when editing a tiddler, newlines immediately following the {{{+++}}} 'start slider' or preceding the {{{===}}} 'end slider' sequence are automatically supressed so that excess whitespace is eliminated from the output.//
===
++++!!!!![Examples]>
simple in-line slider:
{{{
+++
content
===
}}}
+++
content
===
----
use a custom label and tooltip:
{{{
+++[label|tooltip]
content
===
}}}
+++[label|tooltip]
content
===
----
content automatically blockquoted:
{{{
+++>
content
===
}}}
+++>
content
===
----
all options combined //(default open, cookie, heading, sized floater, rollover, label/tooltip/key, blockquoted, deferred)//
{{{
++++(testcookie)!!!^30em^*[label=Z|click or press Alt-Z to open]>...
content
===
}}}
++++(testcookie)!!!^30em^*[label=Z|click or press Alt-Z to open]>...
content
===
----
complex nesting example:
{{{
+++^[get info...=I|click for information or press Alt-I]
put some general information here, plus a floating slider with more specific info:
+++^10em^[view details...|click for details]
put some detail here, which could include a rollover with a +++^25em^*[glossary definition]explaining technical terms===
===
===
}}}
+++^[get info...=I|click for information or press Alt-I]
put some general information here, plus a floating slider with more specific info:
+++^10em^[view details...|click for details]
put some detail here, which could include a rollover with a +++^25em^*[glossary definition]explaining technical terms===
===
===
----
nested floaters
>menu: <<tiddler NestedSlidersExample>>
(see [[NestedSlidersExample]] for definition)
----
===
!!!!!Installation
<<<
import (or copy/paste) the following tiddlers into your document:
''NestedSlidersPlugin'' (tagged with <<tag systemConfig>>)
<<<
!!!!!Revision History
<<<
''2006.05.11 - 1.9.0'' added optional '^width^' syntax for floating sliders and '=key' syntax for setting an access key on a slider label
''2006.05.09 - 1.8.0'' in onClickNestedSlider(), when showing panel, set focus to first child input/textarea/select element
''2006.04.24 - 1.7.8'' in adjustSliderPos(), if floating panel is contained inside another floating panel, subtract offset of containing panel to find correct position
''2006.02.16 - 1.7.7'' corrected deferred rendering to account for use-case where show/hide state is tracked in a cookie
''2006.02.15 - 1.7.6'' in adjustSliderPos(), ensure that floating panel is positioned completely within the browser window (i.e., does not go beyond the right edge of the browser window)
''2006.02.04 - 1.7.5'' add 'var' to unintended global variable declarations to avoid FireFox 1.5.0.1 crash bug when assigning to globals
''2006.01.18 - 1.7.4'' only define adjustSliderPos() function if it has not already been provided by another plugin. This lets other plugins 'hijack' the function even when they are loaded first.
''2006.01.16 - 1.7.3'' added adjustSliderPos(place,btn,panel,panelClass) function to permit specialized logic for placement of floating panels. While it provides improved placement for many uses of floating panels, it exhibits a relative offset positioning error when used within *nested* floating panels. Short-term workaround is to only adjust the position for 'top-level' floaters.
''2006.01.16 - 1.7.2'' added button property to slider panel elements so that slider panel can tell which button it belongs to. Also, re-activated and corrected animation handling so that nested sliders aren't clipped by hijacking Slider.prototype.stop so that "overflow:hidden" can be reset to "overflow:visible" after animation ends
''2006.01.14 - 1.7.1'' added optional "^" syntax for floating panels. Defines new CSS class, ".floatingPanel", as an alternative for standard in-line ".sliderPanel" styles.
''2006.01.14 - 1.7.0'' added optional "*" syntax for rollover handling to show/hide slider without requiring a click (Based on a suggestion by tw4efl)
''2006.01.03 - 1.6.2'' When using optional "!" heading style, instead of creating a clickable "Hn" element, create an "A" element inside the "Hn" element. (allows click-through in SlideShowPlugin, which captures nearly all click events, except for hyperlinks)
''2005.12.15 - 1.6.1'' added optional "..." syntax to invoke deferred ('lazy') rendering for initially hidden sliders
removed checkbox option for 'global' application of lazy sliders
''2005.11.25 - 1.6.0'' added optional handling for 'lazy sliders' (deferred rendering for initially hidden sliders)
''2005.11.21 - 1.5.1'' revised regular expressions: if present, a single newline //preceding// and/or //following// a slider definition will be suppressed so start/end syntax can be place on separate lines in the tiddler 'source' for improved readability. Similarly, any whitespace (newlines, tabs, spaces, etc.) trailing the 'start slider' syntax or preceding the 'end slider' syntax is also suppressed.
''2005.11.20 - 1.5.0'' added (cookiename) syntax for optional tracking and restoring of slider open/close state
''2005.11.11 - 1.4.0'' added !!!!! syntax to render slider label as a header (Hn) style instead of a button/link style
''2005.11.07 - 1.3.0'' removed alternative syntax {{{(((}}} and {{{)))}}} (so they can be used by other
formatting extensions) and simplified/improved regular expressions to trim multiple excess newlines
''2005.11.05 - 1.2.1'' changed name to NestedSlidersPlugin
more documentation
''2005.11.04 - 1.2.0'' added alternative character-mode syntax {{{(((}}} and {{{)))}}}
tweaked "eat newlines" logic for line-mode {{{+++}}} and {{{===}}} syntax
''2005.11.03 - 1.1.1'' fixed toggling of default tooltips ("more..." and "less...") when a non-default button label is used
code cleanup, added documentation
''2005.11.03 - 1.1.0'' changed delimiter syntax from {{{(((}}} and {{{)))}}} to {{{+++}}} and {{{===}}}
changed name to EasySlidersPlugin
''2005.11.03 - 1.0.0'' initial public release
<<<
!!!!!Credits
<<<
This feature was implemented by EricShulman from [[ELS Design Studios|http:/www.elsdesign.com]] with initial research and suggestions from RodneyGomes, GeoffSlocock, and PaulPetterson.
<<<
!!!!!Code
***/
//{{{
version.extensions.nestedSliders = {major: 1, minor: 9, revision: 0, date: new Date(2006,5,11)};
//}}}
//{{{
// options for deferred rendering of sliders that are not initially displayed
if (config.options.chkDebugLazySliderDefer==undefined) config.options.chkDebugLazySliderDefer=false;
if (config.options.chkDebugLazySliderRender==undefined) config.options.chkDebugLazySliderRender=false;
// default styles for 'floating' class
setStylesheet(".floatingPanel { position:absolute; z-index:10; padding:0.5em; margin:0em; \
background-color:#eee; color:#000; border:1px solid #000; text-align:left; }","floatingPanelStylesheet");
//}}}
//{{{
config.formatters.push( {
name: "nestedSliders",
match: "\\n?\\+{3}",
terminator: "\\s*\\={3}\\n?",
lookahead: "\\n?\\+{3}(\\+)?(\\([^\\)]*\\))?(\\!*)?(\\^(?:[^\\^\\*\\[\\>]*\\^)?)?(\\*)?(\\[[^\\]]*\\])?(\\>)?(\\.\\.\\.)?\\s*",
handler: function(w)
{
var lookaheadRegExp = new RegExp(this.lookahead,"mg");
lookaheadRegExp.lastIndex = w.matchStart;
var lookaheadMatch = lookaheadRegExp.exec(w.source)
if(lookaheadMatch && lookaheadMatch.index == w.matchStart)
{
// location for rendering button and panel
var place=w.output;
// default to closed, no cookie, no accesskey
var show="none"; var title=">"; var tooltip="show"; var cookie=""; var key="";
// extra "+", default to open
if (lookaheadMatch[1])
{ show="block"; title="<"; tooltip="hide"; }
// cookie, use saved open/closed state
if (lookaheadMatch[2]) {
cookie=lookaheadMatch[2].trim().slice(1,-1);
cookie="chkSlider"+cookie;
if (config.options[cookie]==undefined)
{ config.options[cookie] = (show=="block") }
if (config.options[cookie])
{ show="block"; title="<"; tooltip="hide"; }
else
{ show="none"; title=">"; tooltip="show"; }
}
// parse custom label/tooltip/accesskey: [label=X|tooltip]
if (lookaheadMatch[6]) {
title = lookaheadMatch[6].trim().slice(1,-1);
var pos=title.indexOf("|");
if (pos!=-1) { tooltip = title.substr(pos+1,title.length); title=title.substr(0,pos); }
if (title.substr(title.length-2,1)=="=") { key=title.substr(title.length-1,1); title=title.slice(0,-2); }
if (pos==-1) tooltip += " "+title; // default tooltip: "show/hide <title>"
}
// create the button
if (lookaheadMatch[3]) { // use "Hn" header format instead of button/link
var lvl=(lookaheadMatch[3].length>6)?6:lookaheadMatch[3].length;
var btn = createTiddlyElement(createTiddlyElement(place,"h"+lvl,null,null,null),"a",null,null,title);
btn.onclick=onClickNestedSlider;
btn.setAttribute("href","javascript:;");
btn.setAttribute("title",tooltip);
}
else
var btn = createTiddlyButton(place,title,tooltip,onClickNestedSlider);
btn.sliderCookie = cookie; // save the cookiename (if any) in the button object
btn.keyparam=key; // save the access key letter ("" if none)
if (key.length) {
btn.setAttribute("accessKey",key); // init access key
btn.onfocus=function(){this.setAttribute("accessKey",this.keyparam);}; // **reclaim** access key on focus
}
// "non-click" MouseOver open/close slider
if (lookaheadMatch[5]) btn.onmouseover=onClickNestedSlider;
// create slider panel
var panelClass=lookaheadMatch[4]?"floatingPanel":"sliderPanel";
var panel=createTiddlyElement(place,"div",null,panelClass,null);
panel.style.display = show;
if (lookaheadMatch[4] && lookaheadMatch[4].length>2) panel.style.width=lookaheadMatch[4].slice(1,-1); // custom width
panel.button = btn; // so the slider panel know which button it belongs to
btn.sliderPanel=panel;
// render slider (or defer until shown)
w.nextMatch = lookaheadMatch.index + lookaheadMatch[0].length;
if ((show=="block")||!lookaheadMatch[8]) {
// render now if panel is supposed to be shown or NOT deferred rendering
w.subWikify(lookaheadMatch[7]?createTiddlyElement(panel,"blockquote"):panel,this.terminator);
// align slider/floater position with button
adjustSliderPos(place,btn,panel,panelClass);
}
else {
var src = w.source.substr(w.nextMatch);
var endpos=findMatchingDelimiter(src,"+++","===");
panel.setAttribute("raw",src.substr(0,endpos));
panel.setAttribute("blockquote",lookaheadMatch[7]?"true":"false");
panel.setAttribute("rendered","false");
w.nextMatch += endpos+3;
if (w.source.substr(w.nextMatch,1)=="\n") w.nextMatch++;
if (config.options.chkDebugLazySliderDefer) alert("deferred '"+title+"':\n\n"+panel.getAttribute("raw"));
}
}
}
}
)
// TBD: ignore 'quoted' delimiters (e.g., "{{{+++foo===}}}" isn't really a slider)
function findMatchingDelimiter(src,starttext,endtext) {
var startpos = 0;
var endpos = src.indexOf(endtext);
// check for nested delimiters
while (src.substring(startpos,endpos-1).indexOf(starttext)!=-1) {
// count number of nested 'starts'
var startcount=0;
var temp = src.substring(startpos,endpos-1);
var pos=temp.indexOf(starttext);
while (pos!=-1) { startcount++; pos=temp.indexOf(starttext,pos+starttext.length); }
// set up to check for additional 'starts' after adjusting endpos
startpos=endpos+endtext.length;
// find endpos for corresponding number of matching 'ends'
while (startcount && endpos!=-1) {
endpos = src.indexOf(endtext,endpos+endtext.length);
startcount--;
}
}
return (endpos==-1)?src.length:endpos;
}
//}}}
//{{{
window.onClickNestedSlider=function(e)
{
if (!e) var e = window.event;
var theTarget = resolveTarget(e);
var theLabel = theTarget.firstChild.data;
var theSlider = theTarget.sliderPanel
var isOpen = theSlider.style.display!="none";
// if using default button labels, toggle labels
if (theLabel==">") theTarget.firstChild.data = "<";
else if (theLabel=="<") theTarget.firstChild.data = ">";
// if using default tooltips, toggle tooltips
if (theTarget.getAttribute("title")=="show")
theTarget.setAttribute("title","hide");
else if (theTarget.getAttribute("title")=="hide")
theTarget.setAttribute("title","show");
if (theTarget.getAttribute("title")=="show "+theLabel)
theTarget.setAttribute("title","hide "+theLabel);
else if (theTarget.getAttribute("title")=="hide "+theLabel)
theTarget.setAttribute("title","show "+theLabel);
// deferred rendering (if needed)
if (theSlider.getAttribute("rendered")=="false") {
if (config.options.chkDebugLazySliderRender)
alert("rendering '"+theLabel+"':\n\n"+theSlider.getAttribute("raw"));
var place=theSlider;
if (theSlider.getAttribute("blockquote")=="true")
place=createTiddlyElement(place,"blockquote");
wikify(theSlider.getAttribute("raw"),place);
theSlider.setAttribute("rendered","true");
}
// show/hide the slider
if(config.options.chkAnimate)
anim.startAnimating(new Slider(theSlider,!isOpen,e.shiftKey || e.altKey,"none"));
else
theSlider.style.display = isOpen ? "none" : "block";
// if showing panel, set focus to first 'focus-able' element in panel
if (theSlider.style.display!="none") {
var ctrls=theSlider.getElementsByTagName("*");
for (var c=0; c<ctrls.length; c++) {
var t=ctrls[c].tagName.toLowerCase();
if (t=="input" || t=="textarea" || t=="select")
{ ctrls[c].focus(); break; }
}
}
if (this.sliderCookie && this.sliderCookie.length)
{ config.options[this.sliderCookie]=!isOpen; saveOptionCookie(this.sliderCookie); }
// align slider/floater position with target button
adjustSliderPos(theSlider.parentNode,theTarget,theSlider,theSlider.className);
return false;
}
// hijack animation handler 'stop' handler so overflow is visible after animation has completed
Slider.prototype.coreStop = Slider.prototype.stop;
Slider.prototype.stop = function() { this.coreStop(); this.element.style.overflow = "visible"; }
// adjust panel position based on button position
if (window.adjustSliderPos==undefined) window.adjustSliderPos=function(place,btn,panel,panelClass) {
if (panelClass=="floatingPanel") {
var left=0;
var top=btn.offsetHeight;
if (place.style.position!="relative") {
var left=findPosX(btn);
var top=findPosY(btn)+btn.offsetHeight;
var p=place; while (p && p.className!='floatingPanel') p=p.parentNode;
if (p) { left-=findPosX(p); top-=findPosY(p); }
}
if (left+panel.offsetWidth > getWindowWidth()) left=getWindowWidth()-panel.offsetWidth-10;
panel.style.left=left+"px"; panel.style.top=top+"px";
}
}
function getWindowWidth() {
if(document.width!=undefined)
return document.width; // moz (FF)
if(document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) )
return document.documentElement.clientWidth; // IE6
if(document.body && ( document.body.clientWidth || document.body.clientHeight ) )
return document.body.clientWidth; // IE4
if(window.innerWidth!=undefined)
return window.innerWidth; // IE - general
return 0; // unknown
}
//}}}
* [[Class Syllabus|syllabus/CS307Syllabus2501.pdf]]
* [[General SOPs]]
* [[Lab Assignments]]
* [[Class Participation]]
** [[Using Discord]]
* [[Shell script submission requirements]]
* [[Shell scripting best practices]]
* [[Material Sections]]
/% ** [[Using Blackboard]] %/
Other helpful material to make things easier:
* [[Working more efficiently with GNU screen & SSH keys]]
* [[Tunnels & Proxies with SSH]]
!!Handouts
[[Command line summary handout|handouts/UnixCommandSummary.pdf]]
[[Substitution Handout|handouts/SubstitutionHandout.pdf]] (from tcsh man page)
[[ASCII Chart|handouts/ascii-chart.gif]]
[[Shell Metacharacter Table|handouts/ShellMetacharacterTable.pdf]]
[[Regular expression metacharacters]]
* [[Metacharacter Handout|handouts/Metacharacters.pdf]] - Metacharacters and how they differ in the shell & regular expression contexts.
[[vi diagram handout|handouts/viDiagram.pdf]]
[[awk handout|handouts/awkHandout.pdf]]
!!Reference Material
[[Class technology stack]] - Mostly my notes for setting up our class servers
[[UNIX in a Nutshell|http://books.google.com/books?id=YkNiiLupct4C&dq=unix+in+a+nutshell&printsec=frontcover&source=bn&hl=en&ei=aKlWS43lJJCOlQeW3rSCBA&sa=X&oi=book_result&ct=result&resnum=5&ved=0CCIQ6AEwBA#v=onepage&q=&f=false]] - Google books
[[The Linux Command Line (No Starch Press)|http://www.merantn.net/reference/TLCL-19.01.pdf]]
[[UNIX Toolbox|https://merantn.net/docs/unixtoolbox.xhtml]]
[[Shell scripting notes]]
[[Table of Commands]]
** [[less quick reference]]
[[Linux Shortcuts]]
/***
|Name|OpenTopPlugin|
|Created by|SaqImtiaz|
|Location|http://lewcid.googlepages.com/lewcid.html#OpenTopPlugin|
|Version|0.1|
|Requires|~TW2.x|
!!!Description:
Open new tiddlers at the top of the screen.
!!!Code
***/
//{{{
Story.prototype.coreLewcidDisplayTiddler=Story.prototype.displayTiddler ;
Story.prototype.displayTiddler =
function(srcElement,title,template,unused1,unused2,animate,slowly)
{
var srcElement=null;
if (document.getElementById(this.idPrefix + title))
{story.closeTiddler(title);}
this.coreLewcidDisplayTiddler(srcElement,title,template,unused1,unused2,animate,slowly);
window.scrollTo(0,0);
}
//}}}
<<option chkSaveBackups>> SaveBackups
<<option chkAutoSave>> AutoSave
<<option chkRegExpSearch>> RegExpSearch
<<option chkCaseSensitiveSearch>> CaseSensitiveSearch
<<option chkAnimate>> EnableAnimations
----
Also see AdvancedOptions
/%
[[Week 3, Part 2]] - Home Directories & Shell documentation
[[Week 3, Part 1]] - Links & File Globbing
* Links:
** Read
*** Chapter 3, pp 23 & 24
*** Chapter 4, pp 33 & 34
** Watch:
*** Links - https://www.youtube.com/watch?v=lW_V8oFxQgA
** Complete: [[Lab 8|labs/lab8.pdf]]
* File Globbing:
** Read: Chapter 4, pp 25-27 (Wildcards)
** Watch:
*** File Globbing: https://www.youtube.com/watch?v=QIysdjpiLcA
*** Brace Expansion: https://www.youtube.com/watch?v=LGzSnVYS2J4
** Complete: [[Lab 9|labs/lab9.pdf]] & [[Lab 10|labs/lab10.pdf]]
----
[[Week 2, Part 2]] - Manipulating Files & Directories
* Review: Complete [[Lab 5|labs/lab5.pdf]]
* Read Chapter 4 in [[The Linux Command Line|http://www.merantn.net/reference/TLCL-19.01.pdf]]
** You can gloss over the parts about wildcards (pp 26-27) for now. We'll come back to them later.
** Focus on becoming familiar with the available commands.
* Watch:
** Creating and Deleting files and directories: https://www.youtube.com/watch?v=91FhiTyEaCU
** Moving and copying files: https://www.youtube.com/watch?v=GKEGNdNIQrw
* Complete [[Lab 6|labs/lab6.pdf]] & [[Lab 7|labs/lab7.pdf]]
[[Week 2, Part 1]] - Exploring the system
* Read Chapter 3 in [[The Linux Command Line|http://www.merantn.net/reference/TLCL-19.01.pdf]]
* Complete [[Lab 3|labs/lab3.pdf]] & [[Lab 4|labs/lab4.pdf]]
----
[[Week 1, Part 2]] - The Filesystem
* Read Chapter 2 in [[The Linux Command Line|http://www.merantn.net/reference/TLCL-19.01.pdf]] - Navigation
* Complete [[Lab 2|labs/Lab2.pdf]]
[[Week 1, Part 1]] - Unix Intro
* Read Chapter 1 in [[The Linux Command Line|http://www.merantn.net/reference/TLCL-19.01.pdf]] - What is the Shell?
* Complete [[Lab 1|labs/Lab1.pdf]]
%/
<!--{{{-->
<div class='header' macro='gradient vert #000 #069'>
<div id='topTitle' class='headerShadow'>
<span class='siteTitle' refresh='content' tiddler='SiteTitle'></span>
<span class='siteSubtitle' refresh='content' tiddler='SiteSubtitle'></span>
</div>
<div id='topTitle' class='headerForeground'>
<span class='siteTitle' refresh='content' tiddler='SiteTitle'></span>
<span class='siteSubtitle' refresh='content' tiddler='SiteSubtitle'></span>
</div>
<div id='topMenu' refresh='content' tiddler='MainMenu'></div>
<div id='rightMenu' refresh='content' tiddler='RightMenu'></div>
</div>
<div id='sidebar'>
<div id='sidebarOptions' refresh='content' tiddler='SideBarOptions'></div>
<div id='sidebarTabs' refresh='content' force='true' tiddler='SideBarTabs'></div>
</div>
<div id='displayArea'>
<div id='messageArea'></div>
<div id='tiddlerDisplay'></div>
</div>
<!--}}}-->
function onClickDefaultHome(e) {
story.closeAllTiddlers();
config.options.txtDefaultTiddlers = "";
saveOptionCookie('txtDefaultTiddlers');
var start = store.getTiddlerText("DefaultTiddlers");
if(start)
story.displayTiddlers(null,start.readBracketedList());
}
config.macros["defaultHome"] = {label: "Home", prompt: "Show the default tiddlers", title: "Home"};
config.macros.defaultHome.handler = function(place) {
createTiddlyButton(place,this.label,this.prompt,onClickDefaultHome);
}
config.macros.listTags = { text: "Hello" };
config.macros.listTags.handler = function(place,macroName,params)
{
var tagged = store.getTaggedTiddlers(params[0]);
var ul = createTiddlyElement(place,"ul",null,null,"");
for(var r=0;r<tagged.length;r++)
{
var li = createTiddlyElement(ul,"li",null,null,"");
createTiddlyLink(li,tagged[r].title,true);
}
}
Type the text for 'Plugins'
<html>
<center>
<video id="my-video" class="video-js" controls preload="auto" width="466" height="448" poster="" data-setup="{}">
<source src="video/PuttyProxy.mp4" type='video/mp4'>
<p class="vjs-no-js">
To view this video please enable JavaScript, and consider upgrading to a web browser that
<a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
</p>
</video>
<script src="https://vjs.zencdn.net/7.8.2/video.min.js"></script>
</center>
</html>
/***
|Name:|QuickOpenTagPlugin|
|Description:|Changes tag links to make it easier to open tags as tiddlers|
|Version:|3.0.1 ($Rev: 3861 $)|
|Date:|$Date: 2008-03-08 10:53:09 +1000 (Sat, 08 Mar 2008) $|
|Source:|http://mptw.tiddlyspot.com/#QuickOpenTagPlugin|
|Author:|Simon Baird <simon.baird@gmail.com>|
|License:|http://mptw.tiddlyspot.com/#TheBSDLicense|
***/
//{{{
config.quickOpenTag = {
dropdownChar: (document.all ? "\u25bc" : "\u25be"), // the little one doesn't work in IE?
createTagButton: function(place,tag,excludeTiddler) {
// little hack so we can do this: <<tag PrettyTagName|RealTagName>>
var splitTag = tag.split("|");
var pretty = tag;
if (splitTag.length == 2) {
tag = splitTag[1];
pretty = splitTag[0];
}
var sp = createTiddlyElement(place,"span",null,"quickopentag");
createTiddlyText(createTiddlyLink(sp,tag,false),pretty);
var theTag = createTiddlyButton(sp,config.quickOpenTag.dropdownChar,
config.views.wikified.tag.tooltip.format([tag]),onClickTag);
theTag.setAttribute("tag",tag);
if (excludeTiddler)
theTag.setAttribute("tiddler",excludeTiddler);
return(theTag);
},
miniTagHandler: function(place,macroName,params,wikifier,paramString,tiddler) {
var tagged = store.getTaggedTiddlers(tiddler.title);
if (tagged.length > 0) {
var theTag = createTiddlyButton(place,config.quickOpenTag.dropdownChar,
config.views.wikified.tag.tooltip.format([tiddler.title]),onClickTag);
theTag.setAttribute("tag",tiddler.title);
theTag.className = "miniTag";
}
},
allTagsHandler: function(place,macroName,params) {
var tags = store.getTags(params[0]);
var filter = params[1]; // new feature
var ul = createTiddlyElement(place,"ul");
if(tags.length == 0)
createTiddlyElement(ul,"li",null,"listTitle",this.noTags);
for(var t=0; t<tags.length; t++) {
var title = tags[t][0];
if (!filter || (title.match(new RegExp('^'+filter)))) {
var info = getTiddlyLinkInfo(title);
var theListItem =createTiddlyElement(ul,"li");
var theLink = createTiddlyLink(theListItem,tags[t][0],true);
var theCount = " (" + tags[t][1] + ")";
theLink.appendChild(document.createTextNode(theCount));
var theDropDownBtn = createTiddlyButton(theListItem," " +
config.quickOpenTag.dropdownChar,this.tooltip.format([tags[t][0]]),onClickTag);
theDropDownBtn.setAttribute("tag",tags[t][0]);
}
}
},
// todo fix these up a bit
styles: [
"/*{{{*/",
"/* created by QuickOpenTagPlugin */",
".tagglyTagged .quickopentag, .tagged .quickopentag ",
" { margin-right:1.2em; border:1px solid #eee; padding:2px; padding-right:0px; padding-left:1px; }",
".quickopentag .tiddlyLink { padding:2px; padding-left:3px; }",
".quickopentag a.button { padding:1px; padding-left:2px; padding-right:2px;}",
"/* extra specificity to make it work right */",
"#displayArea .viewer .quickopentag a.button, ",
"#displayArea .viewer .quickopentag a.tiddyLink, ",
"#mainMenu .quickopentag a.tiddyLink, ",
"#mainMenu .quickopentag a.tiddyLink ",
" { border:0px solid black; }",
"#displayArea .viewer .quickopentag a.button, ",
"#mainMenu .quickopentag a.button ",
" { margin-left:0px; padding-left:2px; }",
"#displayArea .viewer .quickopentag a.tiddlyLink, ",
"#mainMenu .quickopentag a.tiddlyLink ",
" { margin-right:0px; padding-right:0px; padding-left:0px; margin-left:0px; }",
"a.miniTag {font-size:150%;} ",
"#mainMenu .quickopentag a.button ",
" /* looks better in right justified main menus */",
" { margin-left:0px; padding-left:2px; margin-right:0px; padding-right:0px; }",
"#topMenu .quickopentag { padding:0px; margin:0px; border:0px; }",
"#topMenu .quickopentag .tiddlyLink { padding-right:1px; margin-right:0px; }",
"#topMenu .quickopentag .button { padding-left:1px; margin-left:0px; border:0px; }",
"/*}}}*/",
""].join("\n"),
init: function() {
// we fully replace these builtins. can't hijack them easily
window.createTagButton = this.createTagButton;
config.macros.allTags.handler = this.allTagsHandler;
config.macros.miniTag = { handler: this.miniTagHandler };
config.shadowTiddlers["QuickOpenTagStyles"] = this.styles;
store.addNotification("QuickOpenTagStyles",refreshStyles);
}
}
config.quickOpenTag.init();
//}}}
| !Symbol | !Meaning | !Escape | !Not supported by |
| ^ |Start of line| | |
| $ |End of line| | |
| [ ] |Character Classes (match any one character listed) | | |
|~|Characters may be specified singly or in ranges| | |
| [^ ] |Negated character class (match any one character not listed| | |
| ? |Optional item. Match 0 or 1. | | sed |
| ( ) |Alternation (match any one of the sub-expressions)| | |
|~|Grouping| | |
|~|Capture backreference Access with \//n//| * | |
| {{{|}}} |Or. Match either expression it separates. Use with ( )| | |
| . |Any single character| | |
| + |Repetition: 1 or more. | | sed |
| * |Repetition: 0 or more| | |
| { } |Defined range of matches (bounds) {//min//,//max//} or {//min//,} or {//exactly//}| * | |
| \ |Suppress normal behavior of a metacharacter| | |
|~|Access a backreference: \//n//| | |
| \< |Match start of word.| * | bsd sed |
| \> |Match end of word.| * | bsd sed |
| !Symbol | !File Globbing | !Regex | !Regex Equivalent |
| ? |Exactly 1|0 or 1| . |
| { } |Sets|# of matches| ( ) |
/***
|Name:|RenameTagsPlugin|
|Description:|Allows you to easily rename or delete tags across multiple tiddlers|
|Version:|3.0 ($Rev: 5501 $)|
|Date:|$Date: 2008-06-10 23:11:55 +1000 (Tue, 10 Jun 2008) $|
|Source:|http://mptw.tiddlyspot.com/#RenameTagsPlugin|
|Author:|Simon Baird <simon.baird@gmail.com>|
|License|http://mptw.tiddlyspot.com/#TheBSDLicense|
Rename a tag and you will be prompted to rename it in all its tagged tiddlers.
***/
//{{{
config.renameTags = {
prompts: {
rename: "Rename the tag '%0' to '%1' in %2 tidder%3?",
remove: "Remove the tag '%0' from %1 tidder%2?"
},
removeTag: function(tag,tiddlers) {
store.suspendNotifications();
for (var i=0;i<tiddlers.length;i++) {
store.setTiddlerTag(tiddlers[i].title,false,tag);
}
store.resumeNotifications();
store.notifyAll();
},
renameTag: function(oldTag,newTag,tiddlers) {
store.suspendNotifications();
for (var i=0;i<tiddlers.length;i++) {
store.setTiddlerTag(tiddlers[i].title,false,oldTag); // remove old
store.setTiddlerTag(tiddlers[i].title,true,newTag); // add new
}
store.resumeNotifications();
store.notifyAll();
},
storeMethods: {
saveTiddler_orig_renameTags: TiddlyWiki.prototype.saveTiddler,
saveTiddler: function(title,newTitle,newBody,modifier,modified,tags,fields,clearChangeCount,created) {
if (title != newTitle) {
var tagged = this.getTaggedTiddlers(title);
if (tagged.length > 0) {
// then we are renaming a tag
if (confirm(config.renameTags.prompts.rename.format([title,newTitle,tagged.length,tagged.length>1?"s":""])))
config.renameTags.renameTag(title,newTitle,tagged);
if (!this.tiddlerExists(title) && newBody == "")
// dont create unwanted tiddler
return null;
}
}
return this.saveTiddler_orig_renameTags(title,newTitle,newBody,modifier,modified,tags,fields,clearChangeCount,created);
},
removeTiddler_orig_renameTags: TiddlyWiki.prototype.removeTiddler,
removeTiddler: function(title) {
var tagged = this.getTaggedTiddlers(title);
if (tagged.length > 0)
if (confirm(config.renameTags.prompts.remove.format([title,tagged.length,tagged.length>1?"s":""])))
config.renameTags.removeTag(title,tagged);
return this.removeTiddler_orig_renameTags(title);
}
},
init: function() {
merge(TiddlyWiki.prototype,this.storeMethods);
}
}
config.renameTags.init();
//}}}
Type the text for 'Resources'
<<toggleSideBar "" "Toggle Sidebar" hide>>
<html>
<center>
<video id="my-video" class="video-js" controls preload="auto" width="858" height="480" poster="" data-setup="{}">
<source src="video/ssh.mp4" type='video/mp4'>
<p class="vjs-no-js">
To view this video please enable JavaScript, and consider upgrading to a web browser that
<a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
</p>
</video>
<script src="https://vjs.zencdn.net/7.8.2/video.min.js"></script>
</center>
</html>
!! Grading
Shell scripting labs will follow a more traditional grading approach where only meeting the objectives of the script will receive a B grade, or 8.5 / 10. A grade beyond that will require exceeding the minimum expectations.
15% of shell scripting lab grades will be reserved for style, efficiency, and completeness. /% For example, if the %/
| !Grade | !Quality |
| A |Exceptional - Exceeds expectations|
| B |Average - Meets expectations|
| C |Satisfactory - meets some expectations|
| D |Poor - meets minimal expectations|
| F |Does not meet minimal expectations|
!! Requirements
The following procedure must be followed for submitting shell scripting labs. Improperly submitted scripting labs will not be accepted.
The end goal of this process is to submit a single PDF containing these three components:
''a.'' Original lab assignment sheet as a cover page
''b.'' Your shell scripts
''c.'' A demonstration of your scripts
''1.'' Create the directory ~/bin/. Save all lab shell scripts in this directory with the naming convention ''cs307-lab//xx//-q//yy//.sh'' where ''//xx//'' is the lab number and ''//yy//'' is the question number. It would make things easier for you if you always use two digits for //xx// and //yy//.
I may refer to the script files if I need to execute/test any of your scripts.
''2.'' A proper shebang must be added as the first line of your shell scripts.
''3.'' The following header must be placed at the top of each script file, immediately after the shebang:
{{{
# File name:
# Author:
# Date Written:
# Assignment:
# Purpose:
# Description:
#
#
#
}}}
The //Purpose// field should contain a brief, one-line summary of what your script is accomplishing. The Description field should contain more detailed information regarding how it is accomplishing that goal or any additional information helpful to understand the function of your script.
''4.'' Make use of comments throughout your script to document and convey what you're doing.
Long lines should be nicely wrapped with carriage returns. Cut long lines at about column 60. (makes it easier to read and print)
* You can escape the newline with a {{Command{''\''}}} to continue a long line of commands on the next line. For example:
{{{
dig axfr ${user}.cs307.net @ns1.${user}.cs307.net | \
grep -v ^\; | sort | md5sum | cut -d " " -f 1
}}}
{{Note{''Note:'' The remaining two steps are for labs which are //only// scripts and do not contain input boxes}}}
''5.'' Use the {{Command{script}}} command to launch a recording shell, saving the output to {{File{~/bin/labxx.raw}}} where //xx// is the lab number. Demonstrate execution of your scripts within this recording shell.
* Execute {{Command{script ~/bin/labxx.raw}}} to start the recording shell, saving output to the filename specified as the first command line argument
* Run your scripts. Everything you type and all output will be recorded in the file {{File{~/bin/labxx.raw}}}.
* Be sure you do not have excessive errors in the recording. Pressing the backspace key will be recorded as a separate keystroke and make your demonstration harder to read.
* Type {{Command{exit}}} to terminate the recording shell.
* If you examine the {{File{~/bin/labxx.raw}}}, you will see it contains a lot of control characters. The {{Command{ ansifilter }}} command will remove them.
** {{Command{ ansifilter -o ~/bin/labxx.out ~/bin/labxx.raw }}}
''6.'' Create a PDF of your scripts to save to the {{File{/opt/pub/cs307/submit/}}} directory:
* The comments below explain what's going on.
* The first paragraph only explains the {{Command{enscript}}} command. The second paragraph contains the two commands you'll need to execute to submit your lab.
{{{
# enscript is a great tool for formatting documents about to be printed or saved as a PDF.
# The following command string will gather your labs and the output from the demo of your scripts, apply some
# document formatting, and display PostScript on STDOUT.
# The -o - option for enscript instructs the command to sent its output to STDOUT instead of saving it to a file
enscript -2jr -C -o - ~/bin/cs307-labxx-q??.sh ~/bin/labxx.out
# PostScript is mostly the language of printers and isn't as useful on modern PCs. Instead of working with
# native PostScript or displaying STDOUT to the screen, let's convert it to PDF and save to a file.
# Caution! Only run this command when you are ready to submit your scripts.
# *** These are the command you will execute to submit your scripting labs ***
enscript -2jr -C -o - ~/bin/cs307-labxx-q??.sh ~/bin/labxx.out | ps2pdf - ~/bin/cs307-labxx-username.pdf
# Note: The - in the above ps2pdf command instructs the command to obtain its input from STDIN.
# The next command will combine the lab assignment PDF as a cover page with the PDF you just created containing your scripts,
# saving the output to the class submit directory. This is the PDF you are submitting for my review.
cpdf /opt/pub/cs307/labs/labxx.pdf ~/bin/cs307-labxx-username.pdf -o /opt/pub/cs307/submit/cs307-labxx-username.pdf
# Be sure to follow the standard lab naming scheme and change the xx and username to proper values
# The nice thing about using standard naming conventions is it makes everything easy to script.
# Rather than have to search for these commands for every scripting lab you need to submit, you might as well make a dynamic script out of it.
# (Hint: This will be a future assignment. It'll be more useful to you if you start working on it now.)
}}}
''7.'' Preview your submitted PDF
> Download the PDF saved to the {{File{submit/}}} directory to check your work. If you skip this important step and submit a PDF for review that does not contain your scripts, you will either receive no credit for the lab or a late penalty for resubmitting.
{{Note{''Note:'' The video below demonstrates the deprecated {{Command{a2ps}}} command. The new process instead uses {{Command{enscript}}} which is a drop-in replacement. The video has not yet been updated to reflect this change}}}
<html>
<center>
<video id="my-video" class="video-js" controls preload="auto" width="1000" height="662" poster="" data-setup="{}">
<source src="video/scripts.mp4" type='video/mp4'>
<p class="vjs-no-js">
To view this video please enable JavaScript, and consider upgrading to a web browser that
<a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
</p>
</video>
<script src="https://vjs.zencdn.net/7.8.2/video.min.js"></script>
</center>
</html>
The following general best practices will make it much easier for you to write your scripts and help ensure they're correct. Good practices will also help others understand what your scripts are doing.
!! Items to include within your script:
1. Start your script with a proper shebang.
<<<
The first line of your script, the shebang (shell bang because it starts with a {{Monospace{#!}}}) must contain the shell interpreter to use. Since these scripts are otherwise just text files, this line indicates what language your script was written in. Bourne shell scripts should have this on the first line: {{Monospace{''#!/bin/sh''}}}
<<<
2. Provide clarity
<<<
You may not be the only one using your script. Others may have to look at the code to troubleshoot or make modifications later. Or you may have to come back years later to decipher what you did and what your past self was thinking. Good usability should be built into everything you do. Be sure your code is well laid out and clear to follow. If you make it so I have a hard time understanding your logic and workflow with these simple scripts when I know the objective, then others will surely have difficulty understanding more complex ones later.
<<<
3. Add proper header information to your script
<<<
Identifying the script author, creation date, and purpose at the top of your script is important. I encounter far too many scripts written by others at my day job which lack this detail. Who do I go to if there's issues with this script? How old is this? Is it ancient and not valid anymore as processes have changed?
<<<
4. Add comments to explain what you are doing and the purpose of each section
<<<
Comments should be utilized to explain what you are doing or your methodology if the command itself does not make it clear. Simple and obvious commands and processes may be self-documenting. Others should have comments to explain them. It's also helpful to cut your comments at about 60 characters so they don't wrap to the next line in the terminal or PDF copy.
Comments should be concise and professional. Unnecessary verbosity can cause your meaning to be lost.
<<<
5. Cut long lines
<<<
Very long command lines can be cut and extended to the next line to help readability. The backslash can be used to escape the newline if it's the last character in the line. By escaping the newline, your long command string can then continue on the next line.
Consider these two examples. Notice the use of the backslash in the long command string.
{{{
# Combine lab sheet as a cover page with PDF containing shell
# scripts, saving output to submit directory.
cpdf /opt/pub/cs307/labs/labxx.pdf ~/bin/cs307-labxx-username.pdf -o /opt/pub/cs307/submit/cs307-labxx-username.pdf
}}}
{{{
# Combine lab sheet as a cover page with PDF containing shell
# scripts, saving output to submit directory.
cpdf /opt/pub/cs307/labs/labxx.pdf ~/bin/cs307-labxx-username.pdf \
-o /opt/pub/cs307/submit/cs307-labxx-username.pdf
}}}
<<<
6. Use meaningful variable names
<<<
Choose descriptive variable names to make your code self-documenting. If your variable should contain a file name, the name of the variable should be something line {{Monospace{''//filename//''}}}, not something generic like {{Monospace{''//var//''}}}. Also avoid using one-letter variable names (e.g., {{Monospace{x}}} or {{Monospace{i}}} when possible.
<<<
7. Use double quotes with variables (when you can)
<<<
Enclose variables in double quotes to handle spaces and special characters correctly, especially when using variables within if-statements. There may be times you cannot use quotes, but these are the exception and not the norm.
<<<
8. Properly indent your code
<<<
Follow a consistent and readable indentation style to make your code visually appealing and logic easier to follow. Any control structures should be properly indented.
Consider these two small examples. The first with no indentation and the second with proper indentation. The issue becomes more pronounced as control structures become nested and larger.
{{{
if [ -n "$note" ]
then
echo $note
fi
}}}
{{{
if [ -n "$note" ]
then
echo $note
fi
}}}
<<<
9. Avoid hardcoding values
<<<
Minimize hardcoding values in your script. Use variables or configuration files to store and manage settings. For example, if you have to refer to a file later in your script, perhaps defining a variable at the top of the script would make the script easier to maintain?
<<<
10. Avoid code duplication
<<<
Avoid using the same block of code in multiple places within your script. If you find that you have done this, then look at ways to either adjust the script's logic or approach to remove the code reuse. We aren't covering functions here, but proper use of functions can typically help with this in larger scripts.
<<<
!! Script validation and debugging
1. Debugging statements may be helpful
<<<
You can run your script with {{Monospace{bash -x}}} to see the actual lines that are being executed in your script, after any substitutions occur. This can be a great tool for identifying why something isn't working out the way it should.
{{{
bash -x scriptname.sh
}}}
Debugging {{Monospace{echo}}} statements throughout your script can help show any intermediate values as they're being used. This way we can more easily visualize what these variables contain as the script is executing.
{{{
echo DEBUG: $mdate : $mtime : $oneday : $threeday
}}}
Just remember to remove or comment them before submitting the script
<<<
2. Test your script
<<<
Write test cases to ensure your script works as expected, especially when making changes or updates. Be sure to test different scenarios and test for failure. Don't just provide what's expected. What happens if unexpected input is provided.
We won't have all the tools to handle this when we start our shell scripting work, but we should by the end.
<<<
3. Use version control or make backups
<<<
Keep your scripts in a version control system (e.g., Git) to track changes and easily roll back to an old version if you need to.
Even if you don't use a full version control system, always have a back-out plan if a change doesn't work. Maybe back up the file before making changes so you can revert or comment out the old line until you're sure its no longer needed. My convention is to append a timestamp of the backup to the filename in the format - ~YYMMDD-HHMM. For example, 230320-2244 for 10:44pm on Mar 20. This timestamp then also sorts well in a directory listing. The {{Command{diff}}} command can be used to compare different versions of a file.
The same concept works well for configuration files in our next class material.
<<<
*Shell scripting quick reference: http://www.math.uga.edu/~caner/08reu/shell.html
*Awk one liners: http://www.catonmat.net/blog/wp-content/uploads/2008/09/awk1line.txt
*Sed one liners: http://www.catonmat.net/blog/wp-content/uploads/2008/09/sed1line.txt
<<search>><<closeAll>><<collapseAll>><<expandAll>><<permaview>><<newTiddler>><<saveChanges>><<slider chkSliderOptionsPanel OptionsPanel "options »" "Change TiddlyWiki advanced options">><<slider chkSliderContents [[TabContents]] 'contents »' 'contents'>>
/*{{{*/
#sidebar {
color: #000;
background: transparent;
}
#sidebarOptions {
background: #fff;
}
#sidebarOptions .button {
color: #999;
}
#sidebarOptions .button:hover {
color: #000;
background: #fff;
border-color:white;
}
#sidebarOptions .button:active {
color: #000;
background: #fff;
}
#sidebarOptions .sliderPanel {
background: transparent;
}
#sidebarOptions .sliderPanel A:hover {
color: #000;
background: #fff;
}
#sidebarOptions .sliderPanel A:active {
color: #000;
background: #fff;
}
.sidebarSubHeading {
color: #000;
}
#sidebarOptions .sliderPanel .tabSelected{
border: 1px solid #ccc;
background-color: #fff;
margin: 0px;
padding-top: 5px;
padding-bottom: 0px;
padding-left: 2px;
padding-right: 2px;
-moz-border-radius-topleft: 1em;
-moz-border-radius-topright: 1em;}
#sidebarOptions .sliderPanel .tabUnselected{
border: 1px solid #ccc;
background-color: #eee;
margin: 0px;
padding-top: 5px;
padding-bottom: 0px;
padding-left: 2px;
padding-right: 2px;
-moz-border-radius-topleft: 1em;
-moz-border-radius-topright: 1em;}
#sidebarTabs .tabContents .tiddlyLink:hover {
background: #fff;
color: #000;
}
#sidebarTabs .tabContents {
color: #000;
}
#sidebarTabs .button {
color: #666;
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-bottom: 2px solid #ccc;
border-right: 2px solid #ccc;
}
#sidebarTabs .tabContents .button:hover {
color: #000;
background: #fff;
}
.tagging, .tagged {
padding: 0.5em;
background-color: #eee;
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-bottom: 3px solid #ccc;
border-right: 3px solid #ccc;
-moz-border-radius: 1em; }
/*}}}*/
CS 307 - UNIX Programming Environment - SUNY Polytechnic Institute
[[HorizontalMainMenuStyles]]
[[SideBarStyles]]
[[TagglyTaggingStyles]]
/*{{{*/
body {
background: #eee; }
h1 {font-size:2.0em; }
h2 { color: #000; background: transparent; text-decoration: underline; }
h3 { margin: 0.0em; color: #000; background: transparent; }
h4,h5 { color: #000; background: transparent; }
h1 {
margin: 4px 0 4px 0;
padding: 5px;
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::PrimaryPale]];
}
ul {
margin-top: 0;
margin-bottom: 0;
}
.headerShadow {
padding: 1.0em; }
.headerForeground {
padding: 1.0em; }
.selected .tagging, .selected .tagged {
padding: 0.5em;
background-color: #eee;
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-bottom: 3px solid #ccc;
border-right: 3px solid #ccc;
-moz-border-radius: 1em; }
.shadow .title {
color: #999; }
.siteTitle {
font-size: 2.5em; }
.siteSubtitle {
font-size: 1.0em; }
.subtitle {
font-size: 0.8em;
}
.tagging, .tagged {
padding: 0.5em;
background-color: #eee;
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-bottom: 3px solid #ccc;
border-right: 3px solid #ccc;
-moz-border-radius: 1em; }
.tiddler {
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-bottom: 3px solid #ccc;
border-right: 3px solid #ccc;
margin: 0.5em;
background:#fff;
padding: 0.5em;
-moz-border-radius: 1em; }
.title {
color:black;
font-size: 1.5em; }
.tabSelected{
padding-top: 0.0em;
padding-left: 0.5em;
padding-right: 0.5em;
-moz-border-radius-topleft: 0.5em;
-moz-border-radius-topright: 0.5em;}
.tabUnselected {
padding-top: 0.0em;
padding-left: 0.5em;
padding-right: 0.5em;
-moz-border-radius-topleft: 0.5em;
-moz-border-radius-topright: 0.5em;}
.tabContents {
margin: 0px;
padding-top: 0px;
padding-bottom: 0px;
padding-left: 2px;
padding-right: 2px;
-moz-border-radius: 1em; }
.viewer .listTitle {
list-style-type: none;
}
.viewer pre {
background-color: #f8f8ff;
border-color: #ddf; }
#messageArea { background-color:#bde; border-color:#8ab; border-width:4px; border-style:dotted; font-size:90%; }
#messageArea .button { text-decoration:none; font-weight:bold; background:transparent; border:0px; }
#messageArea .button:hover {background: #acd;}
/*}}}*/
/*{{{*/
.Command{color: fuchsia;font-size: 10pt;font-family: Courier, monospace;margin-left: 2px;margin-right: 2px;}
.Commandi{color: fuchsia;font-size: 10pt;font-family: Courier, monospace;margin-left: 20px;margin-right: 2px;}
.File{color: #4c7fbc;font-size: 10pt;font-family: Courier, monospace;margin-left: 2px;margin-right: 2px; font-weight:bold;}
.Remove{background-color: orange}
.Host{color: #0f9791;font-size: 10pt;font-family: Courier, monospace;margin-left: 2px;margin-right: 2px; font-weight:bold;}
.Note{display:block;background-color:#e9ffdb;border:1px solid darkgreen;margin: 0 2em 0 2em;padding:5px 5px 5px 5px;}
.Warning{display:block;background-color:#ffee88; border:2px solid darkorange;margin: 0 2em 0 2em;padding:5px 5px 5px 5px;}
.Monospaced{font-size: 10pt;font-family: Courier, monospace;margin-left: 2px;margin-right: 2px;}
.Commands{background-color:#F0F0FF; font-size: 10pt;font-family: Courier, monospace;margin-left: 2px;margin-right: 2px;padding:5px 5px 5px 5px;}
/*}}}*/
.HideSideBarButton {margin-left: 3em;}
.viewer div.centeredTable {
text-align: center;
}
.viewer div.centeredTable table {
margin: 0 auto;
text-align: left;
}
.viewer table.borderless,
.viewer table.borderless * {
border: 0;
}
/*{{{*/
body {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}
a {color:[[ColorPalette::PrimaryMid]];}
a:hover {background-color:[[ColorPalette::PrimaryMid]]; color:[[ColorPalette::Background]];}
a img {border:0;}
h1,h2,h3,h4,h5,h6 {color:[[ColorPalette::SecondaryDark]]; background:transparent;}
h1 {border-bottom:2px solid [[ColorPalette::PrimaryLight]];} */
h2,h3 {border-bottom:1px solid [[ColorPalette::TertiaryLight]];}
.button {color:[[ColorPalette::PrimaryDark]]; border:1px solid [[ColorPalette::Background]];}
.button:hover {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::SecondaryLight]]; border-color:[[ColorPalette::SecondaryMid]];}
.button:active {color:[[ColorPalette::Background]]; background:[[ColorPalette::SecondaryMid]]; border:1px solid [[ColorPalette::SecondaryDark]];}
.header {background:[[ColorPalette::PrimaryMid]];}
.headerShadow {color:[[ColorPalette::Foreground]];}
.headerShadow a {font-weight:normal; color:[[ColorPalette::Foreground]];}
.headerForeground {color:[[ColorPalette::Background]];}
.headerForeground a {font-weight:normal; color:[[ColorPalette::PrimaryPale]];}
.tabSelected{color:[[ColorPalette::PrimaryDark]];
background:[[ColorPalette::TertiaryPale]];
border-left:1px solid [[ColorPalette::TertiaryLight]];
border-top:1px solid [[ColorPalette::TertiaryLight]];
border-right:1px solid [[ColorPalette::TertiaryLight]];
}
.tabUnselected {color:[[ColorPalette::Background]]; background:[[ColorPalette::TertiaryMid]];}
.tabContents {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::TertiaryPale]]; border:1px solid [[ColorPalette::TertiaryLight]];}
.tabContents .button {border:0;}
#sidebar {}
#sidebarOptions input {border:1px solid [[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel {background:[[ColorPalette::PrimaryPale]];}
#sidebarOptions .sliderPanel a {border:none;color:[[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel a:hover {color:[[ColorPalette::Background]]; background:[[ColorPalette::PrimaryMid]];}
#sidebarOptions .sliderPanel a:active {color:[[ColorPalette::PrimaryMid]]; background:[[ColorPalette::Background]];}
.wizard {background:[[ColorPalette::PrimaryPale]]; border:1px solid [[ColorPalette::PrimaryMid]];}
.wizard h1 {color:[[ColorPalette::PrimaryDark]]; border:none;}
.wizard h2 {color:[[ColorPalette::Foreground]]; border:none;}
.wizardStep {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];
border:1px solid [[ColorPalette::PrimaryMid]];}
.wizardStep.wizardStepDone {background:[[ColorPalette::TertiaryLight]];}
.wizardFooter {background:[[ColorPalette::PrimaryPale]];}
.wizardFooter .status {background:[[ColorPalette::PrimaryDark]]; color:[[ColorPalette::Background]];}
.wizard .button {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::SecondaryLight]]; border: 1px solid;
border-color:[[ColorPalette::SecondaryPale]] [[ColorPalette::SecondaryDark]] [[ColorPalette::SecondaryDark]] [[ColorPalette::SecondaryPale]];}
.wizard .button:hover {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::Background]];}
.wizard .button:active {color:[[ColorPalette::Background]]; background:[[ColorPalette::Foreground]]; border: 1px solid;
border-color:[[ColorPalette::PrimaryDark]] [[ColorPalette::PrimaryPale]] [[ColorPalette::PrimaryPale]] [[ColorPalette::PrimaryDark]];}
.wizard .notChanged {background:transparent;}
.wizard .changedLocally {background:#80ff80;}
.wizard .changedServer {background:#8080ff;}
.wizard .changedBoth {background:#ff8080;}
.wizard .notFound {background:#ffff80;}
.wizard .putToServer {background:#ff80ff;}
.wizard .gotFromServer {background:#80ffff;}
#messageArea {border:1px solid [[ColorPalette::SecondaryMid]]; background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]];}
#messageArea .button {color:[[ColorPalette::PrimaryMid]]; background:[[ColorPalette::SecondaryPale]]; border:none;}
.popupTiddler {background:[[ColorPalette::TertiaryPale]]; border:2px solid [[ColorPalette::TertiaryMid]];}
.popup {background:[[ColorPalette::TertiaryPale]]; color:[[ColorPalette::TertiaryDark]]; border-left:1px solid [[ColorPalette::TertiaryMid]]; border-top:1px solid [[ColorPalette::TertiaryMid]]; border-right:2px solid [[ColorPalette::TertiaryDark]]; border-bottom:2px solid [[ColorPalette::TertiaryDark]];}
.popup hr {color:[[ColorPalette::PrimaryDark]]; background:[[ColorPalette::PrimaryDark]]; border-bottom:1px;}
.popup li.disabled {color:[[ColorPalette::TertiaryMid]];}
.popup li a, .popup li a:visited {color:[[ColorPalette::Foreground]]; border: none;}
.popup li a:hover {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; border: none;}
.popup li a:active {background:[[ColorPalette::SecondaryPale]]; color:[[ColorPalette::Foreground]]; border: none;}
.popupHighlight {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}
.listBreak div {border-bottom:1px solid [[ColorPalette::TertiaryDark]];}
.tiddler .defaultCommand {font-weight:bold;}
.shadow .title {color:[[ColorPalette::TertiaryDark]];}
.title {color:[[ColorPalette::SecondaryDark]];}
.subtitle {color:[[ColorPalette::TertiaryDark]];}
.toolbar {color:[[ColorPalette::PrimaryMid]];}
.toolbar a {color:[[ColorPalette::TertiaryLight]];}
.selected .toolbar a {color:[[ColorPalette::TertiaryMid]];}
.selected .toolbar a:hover {color:[[ColorPalette::Foreground]];}
.tagging, .tagged {border:1px solid [[ColorPalette::TertiaryPale]]; background-color:[[ColorPalette::TertiaryPale]];}
.selected .tagging, .selected .tagged {background-color:[[ColorPalette::TertiaryLight]]; border:1px solid [[ColorPalette::TertiaryMid]];}
.tagging .listTitle, .tagged .listTitle {color:[[ColorPalette::PrimaryDark]];}
.tagging .button, .tagged .button {border:none;}
.footer {color:[[ColorPalette::TertiaryLight]];}
.selected .footer {color:[[ColorPalette::TertiaryMid]];}
.sparkline {background:[[ColorPalette::PrimaryPale]]; border:0;}
.sparktick {background:[[ColorPalette::PrimaryDark]];}
.error, .errorButton {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::Error]];}
.warning {color:[[ColorPalette::Foreground]]; background:[[ColorPalette::SecondaryPale]];}
.lowlight {background:[[ColorPalette::TertiaryLight]];}
.zoomer {background:none; color:[[ColorPalette::TertiaryMid]]; border:3px solid [[ColorPalette::TertiaryMid]];}
.imageLink, #displayArea .imageLink {background:transparent;}
.annotation {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; border:2px solid [[ColorPalette::SecondaryMid]];}
.viewer .listTitle {list-style-type:none; margin-left:-2em;}
.viewer .button {border:1px solid [[ColorPalette::SecondaryMid]];}
.viewer blockquote {border-left:3px solid [[ColorPalette::TertiaryDark]];}
.viewer table, table.twtable {border:2px solid [[ColorPalette::TertiaryDark]];}
.viewer th, .viewer thead td, .twtable th, .twtable thead td {background:[[ColorPalette::SecondaryMid]]; border:1px solid [[ColorPalette::TertiaryDark]]; color:[[ColorPalette::Background]];}
.viewer td, .viewer tr, .twtable td, .twtable tr {border:1px solid [[ColorPalette::TertiaryDark]];}
.viewer pre {border:1px solid [[ColorPalette::SecondaryLight]]; background:[[ColorPalette::SecondaryPale]];}
.viewer code {color:[[ColorPalette::SecondaryDark]];}
.viewer hr {border:0; border-top:dashed 1px [[ColorPalette::TertiaryDark]]; color:[[ColorPalette::TertiaryDark]];}
.highlight, .marked {background:[[ColorPalette::SecondaryLight]];}
.editor input {border:1px solid [[ColorPalette::PrimaryMid]];}
.editor textarea {border:1px solid [[ColorPalette::PrimaryMid]]; width:100%;}
.editorFooter {color:[[ColorPalette::TertiaryMid]];}
#backstageArea {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::TertiaryMid]];}
#backstageArea a {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::Background]]; border:none;}
#backstageArea a:hover {background:[[ColorPalette::SecondaryLight]]; color:[[ColorPalette::Foreground]]; }
#backstageArea a.backstageSelTab {background:[[ColorPalette::Background]]; color:[[ColorPalette::Foreground]];}
#backstageButton a {background:none; color:[[ColorPalette::Background]]; border:none;}
#backstageButton a:hover {background:[[ColorPalette::Foreground]]; color:[[ColorPalette::Background]]; border:none;}
#backstagePanel {background:[[ColorPalette::Background]]; border-color: [[ColorPalette::Background]] [[ColorPalette::TertiaryDark]] [[ColorPalette::TertiaryDark]] [[ColorPalette::TertiaryDark]];}
.backstagePanelFooter .button {border:none; color:[[ColorPalette::Background]];}
.backstagePanelFooter .button:hover {color:[[ColorPalette::Foreground]];}
#backstageCloak {background:[[ColorPalette::Foreground]]; opacity:0.6; filter:'alpha(opacity:60)';}
/*}}}*/
/*{{{*/
body {
background: [[ColorPalette::Background]];
color: [[ColorPalette::Foreground]];
}
a{
color: [[ColorPalette::PrimaryMid]];
}
a:hover{
background: [[ColorPalette::PrimaryMid]];
color: [[ColorPalette::Background]];
}
a img{
border: 0;
}
h1,h2,h3,h4,h5 {
color: [[ColorPalette::SecondaryDark]];
background: [[ColorPalette::PrimaryPale]];
}
.button {
color: [[ColorPalette::PrimaryDark]];
border: 1px solid [[ColorPalette::Background]];
}
.button:hover {
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::SecondaryLight]];
border-color: [[ColorPalette::SecondaryMid]];
}
.button:active {
color: [[ColorPalette::Background]];
background: [[ColorPalette::SecondaryMid]];
border: 1px solid [[ColorPalette::SecondaryDark]];
}
.header {
background: [[ColorPalette::PrimaryMid]];
}
.headerShadow {
color: [[ColorPalette::Foreground]];
}
.headerShadow a {
font-weight: normal;
color: [[ColorPalette::Foreground]];
}
.headerForeground {
color: [[ColorPalette::Background]];
}
.headerForeground a {
font-weight: normal;
color: [[ColorPalette::PrimaryPale]];
}
.tabSelected{
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::TertiaryPale]];
border-left: 1px solid [[ColorPalette::TertiaryLight]];
border-top: 1px solid [[ColorPalette::TertiaryLight]];
border-right: 1px solid [[ColorPalette::TertiaryLight]];
}
.tabUnselected {
color: [[ColorPalette::Background]];
background: [[ColorPalette::TertiaryMid]];
}
.tabContents {
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::TertiaryPale]];
border: 1px solid [[ColorPalette::TertiaryLight]];
}
.tabContents .button {
border: 0;}
#sidebar {
}
#sidebarOptions input {
border: 1px solid [[ColorPalette::PrimaryMid]];
}
#sidebarOptions .sliderPanel {
background: [[ColorPalette::PrimaryPale]];
}
#sidebarOptions .sliderPanel a {
border: none;
color: [[ColorPalette::PrimaryMid]];
}
#sidebarOptions .sliderPanel a:hover {
color: [[ColorPalette::Background]];
background: [[ColorPalette::PrimaryMid]];
}
#sidebarOptions .sliderPanel a:active {
color: [[ColorPalette::PrimaryMid]];
background: [[ColorPalette::Background]];
}
.wizard {
background: [[ColorPalette::SecondaryLight]];
border-top: 1px solid [[ColorPalette::SecondaryMid]];
border-left: 1px solid [[ColorPalette::SecondaryMid]];
}
.wizard h1 {
color: [[ColorPalette::SecondaryDark]];
}
.wizard h2 {
color: [[ColorPalette::Foreground]];
}
.wizardStep {
background: [[ColorPalette::Background]];
border-top: 1px solid [[ColorPalette::SecondaryMid]];
border-bottom: 1px solid [[ColorPalette::SecondaryMid]];
border-left: 1px solid [[ColorPalette::SecondaryMid]];
}
.wizard .button {
color: [[ColorPalette::Background]];
background: [[ColorPalette::PrimaryMid]];
border-top: 1px solid [[ColorPalette::PrimaryLight]];
border-right: 1px solid [[ColorPalette::PrimaryDark]];
border-bottom: 1px solid [[ColorPalette::PrimaryDark]];
border-left: 1px solid [[ColorPalette::PrimaryLight]];
}
.wizard .button:hover {
color: [[ColorPalette::PrimaryLight]];
background: [[ColorPalette::PrimaryDark]];
border-color: [[ColorPalette::PrimaryLight]];
}
.wizard .button:active {
color: [[ColorPalette::Background]];
background: [[ColorPalette::PrimaryMid]];
border-top: 1px solid [[ColorPalette::PrimaryLight]];
border-right: 1px solid [[ColorPalette::PrimaryDark]];
border-bottom: 1px solid [[ColorPalette::PrimaryDark]];
border-left: 1px solid [[ColorPalette::PrimaryLight]];
}
#messageArea {
border: 1px solid [[ColorPalette::SecondaryDark]];
background: [[ColorPalette::SecondaryMid]];
color: [[ColorPalette::PrimaryDark]];
}
#messageArea .button {
padding: 0.2em 0.2em 0.2em 0.2em;
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::Background]];
}
.popup {
background: [[ColorPalette::PrimaryLight]];
border: 1px solid [[ColorPalette::PrimaryMid]];
}
.popup hr {
color: [[ColorPalette::PrimaryDark]];
background: [[ColorPalette::PrimaryDark]];
border-bottom: 1px;
}
.popup li.disabled {
color: [[ColorPalette::PrimaryMid]];
}
.popup li a, .popup li a:visited {
color: [[ColorPalette::TertiaryPale]];
border: none;
}
.popup li a:hover {
background: [[ColorPalette::PrimaryDark]];
color: [[ColorPalette::Background]];
border: none;
}
.tiddler .defaultCommand {
font-weight: bold;
}
.shadow .title {
color: [[ColorPalette::TertiaryDark]];
}
.title {
color: [[ColorPalette::SecondaryDark]];
}
.subtitle {
color: [[ColorPalette::TertiaryDark]];
}
.toolbar {
color: [[ColorPalette::PrimaryMid]];
}
.tagging, .tagged {
border: 1px solid [[ColorPalette::TertiaryPale]];
background-color: [[ColorPalette::TertiaryPale]];
}
.selected .tagging, .selected .tagged {
background-color: [[ColorPalette::TertiaryLight]];
border: 1px solid [[ColorPalette::TertiaryMid]];
}
.tagging .listTitle, .tagged .listTitle {
color: [[ColorPalette::PrimaryDark]];
}
.tagging .button, .tagged .button {
border: none;
}
.footer {
color: [[ColorPalette::TertiaryLight]];
}
.selected .footer {
color: [[ColorPalette::TertiaryMid]];
}
.sparkline {
background: [[ColorPalette::PrimaryPale]];
border: 0;
}
.sparktick {
background: [[ColorPalette::PrimaryDark]];
}
.error, .errorButton {
color: [[ColorPalette::Foreground]];
background: [[ColorPalette::Error]];
}
.warning {
color: [[ColorPalette::Foreground]];
background: [[ColorPalette::SecondaryPale]];
}
.cascade {
background: [[ColorPalette::TertiaryPale]];
color: [[ColorPalette::TertiaryMid]];
border: 1px solid [[ColorPalette::TertiaryMid]];
}
.imageLink, #displayArea .imageLink {
background: transparent;
}
.viewer .listTitle {list-style-type: none; margin-left: -2em;}
.viewer .button {
border: 1px solid [[ColorPalette::SecondaryMid]];
}
.viewer blockquote {
border-left: 3px solid [[ColorPalette::TertiaryDark]];
}
.viewer table {
border: 2px solid [[ColorPalette::TertiaryDark]];
}
.viewer th, thead td {
background: [[ColorPalette::SecondaryMid]];
border: 1px solid [[ColorPalette::TertiaryDark]];
color: [[ColorPalette::Background]];
}
.viewer td, .viewer tr {
border: 1px solid [[ColorPalette::TertiaryDark]];
}
.viewer pre {
border: 1px solid [[ColorPalette::SecondaryLight]];
background: [[ColorPalette::SecondaryPale]];
}
.viewer code {
color: [[ColorPalette::SecondaryDark]];
}
.viewer hr {
border: 0;
border-top: dashed 1px [[ColorPalette::TertiaryDark]];
color: [[ColorPalette::TertiaryDark]];
}
.highlight, .marked {
background: [[ColorPalette::SecondaryLight]];
}
.editor input {
border: 1px solid [[ColorPalette::PrimaryMid]];
}
.editor textarea {
border: 1px solid [[ColorPalette::PrimaryMid]];
width: 100%;
}
.editorFooter {
color: [[ColorPalette::TertiaryMid]];
}
/*}}}*/
/*{{{*/
* html .tiddler {height:1%;}
body {font-size:.75em; font-family:arial,helvetica; margin:0; padding:0;}
h1,h2,h3,h4,h5,h6 {font-weight:bold; text-decoration:none;}
h1,h2,h3 {padding-bottom:1px; margin-top:1.2em;margin-bottom:0.3em;}
h4,h5,h6 {margin-top:0em;margin-bottom:0em;}
h1 {font-size:1.35em;}
h2 {font-size:1.25em;}
h3 {font-size:1.1em;}
h4 {font-size:1em;}
h5 {font-size:.9em;}
hr {height:1px;}
a {text-decoration:none;}
dt {font-weight:bold;}
ol {list-style-type:decimal;}
ol ol {list-style-type:lower-alpha;}
ol ol ol {list-style-type:lower-roman;}
ol ol ol ol {list-style-type:decimal;}
ol ol ol ol ol {list-style-type:lower-alpha;}
ol ol ol ol ol ol {list-style-type:lower-roman;}
ol ol ol ol ol ol ol {list-style-type:decimal;}
.txtOptionInput {width:11em;}
#contentWrapper .chkOptionInput {border:0;}
.externalLink {text-decoration:underline;}
.indent {margin-left:3em;}
.outdent {margin-left:3em; text-indent:-3em;}
code.escaped {white-space:nowrap;}
.tiddlyLinkExisting {font-weight:bold;}
.tiddlyLinkNonExisting {font-style:italic;}
/* the 'a' is required for IE, otherwise it renders the whole tiddler in bold */
a.tiddlyLinkNonExisting.shadow {font-weight:bold;}
#mainMenu .tiddlyLinkExisting,
#mainMenu .tiddlyLinkNonExisting,
#sidebarTabs .tiddlyLinkNonExisting {font-weight:normal; font-style:normal;}
#sidebarTabs .tiddlyLinkExisting {font-weight:bold; font-style:normal;}
.header {position:relative;}
.header a:hover {background:transparent;}
.headerShadow {position:relative; padding:4.5em 0em 1em 1em; left:-1px; top:-1px;}
.headerForeground {position:absolute; padding:4.5em 0em 1em 1em; left:0px; top:0px;}
.siteTitle {font-size:3em;}
.siteSubtitle {font-size:1.2em;}
#mainMenu {position:absolute; left:0; width:10em; text-align:right; line-height:1.6em; padding:1.5em 0.5em 0.5em 0.5em; font-size:1.1em;}
#sidebar {position:absolute; right:3px; width:16em; font-size:.9em;}
#sidebarOptions {padding-top:0.3em;}
#sidebarOptions a {margin:0em 0.2em; padding:0.2em 0.3em; display:block;}
#sidebarOptions input {margin:0.4em 0.5em;}
#sidebarOptions .sliderPanel {margin-left:1em; padding:0.5em; font-size:.85em;}
#sidebarOptions .sliderPanel a {font-weight:bold; display:inline; padding:0;}
#sidebarOptions .sliderPanel input {margin:0 0 .3em 0;}
#sidebarTabs .tabContents {width:15em; overflow:hidden;}
.wizard {padding:0.1em 1em 0em 2em;}
.wizard h1 {font-size:2em; font-weight:bold; background:none; padding:0em 0em 0em 0em; margin:0.4em 0em 0.2em 0em;}
.wizard h2 {font-size:1.2em; font-weight:bold; background:none; padding:0em 0em 0em 0em; margin:0.4em 0em 0.2em 0em;}
.wizardStep {padding:1em 1em 1em 1em;}
.wizard .button {margin:0.5em 0em 0em 0em; font-size:1.2em;}
.wizardFooter {padding:0.8em 0.4em 0.8em 0em;}
.wizardFooter .status {padding:0em 0.4em 0em 0.4em; margin-left:1em;}
.wizard .button {padding:0.1em 0.2em 0.1em 0.2em;}
#messageArea {position:fixed; top:2em; right:0em; margin:0.5em; padding:0.5em; z-index:2000; _position:absolute;}
.messageToolbar {display:block; text-align:right; padding:0.2em 0.2em 0.2em 0.2em;}
#messageArea a {text-decoration:underline;}
.tiddlerPopupButton {padding:0.2em 0.2em 0.2em 0.2em;}
.popupTiddler {position: absolute; z-index:300; padding:1em 1em 1em 1em; margin:0;}
.popup {position:absolute; z-index:300; font-size:.9em; padding:0; list-style:none; margin:0;}
.popup .popupMessage {padding:0.4em;}
.popup hr {display:block; height:1px; width:auto; padding:0; margin:0.2em 0em;}
.popup li.disabled {padding:0.4em;}
.popup li a {display:block; padding:0.4em; font-weight:normal; cursor:pointer;}
.listBreak {font-size:1px; line-height:1px;}
.listBreak div {margin:2px 0;}
.tabset {padding:1em 0em 0em 0.5em;}
.tab {margin:0em 0em 0em 0.25em; padding:2px;}
.tabContents {padding:0.5em;}
.tabContents ul, .tabContents ol {margin:0; padding:0;}
.txtMainTab .tabContents li {list-style:none;}
.tabContents li.listLink { margin-left:.75em;}
#contentWrapper {display:block;}
#splashScreen {display:none;}
#displayArea {margin:1em 17em 0em 14em;}
.toolbar {text-align:right; font-size:.9em;}
.tiddler {padding:1em 1em 0em 1em;}
.missing .viewer,.missing .title {font-style:italic;}
.title {font-size:1.6em; font-weight:bold;}
.missing .subtitle {display:none;}
.subtitle {font-size:1.1em;}
.tiddler .button {padding:0.2em 0.4em;}
.tagging {margin:0.5em 0.5em 0.5em 0; float:left; display:none;}
.isTag .tagging {display:block;}
.tagged {margin:0.5em; float:right;}
.tagging, .tagged {font-size:0.9em; padding:0.25em;}
.tagging ul, .tagged ul {list-style:none; margin:0.25em; padding:0;}
.tagClear {clear:both;}
.footer {font-size:.9em;}
.footer li {display:inline;}
.annotation {padding:0.5em; margin:0.5em;}
* html .viewer pre {width:99%; padding:0 0 1em 0;}
.viewer {line-height:1.4em; padding-top:0.5em;}
.viewer .button {margin:0em 0.25em; padding:0em 0.25em;}
.viewer blockquote {line-height:1.5em; padding-left:0.8em;margin-left:2.5em;}
.viewer ul, .viewer ol {margin-left:0.5em; padding-left:1.5em;}
.viewer table, table.twtable {border-collapse:collapse; margin:0.8em 1.0em;}
.viewer th, .viewer td, .viewer tr,.viewer caption,.twtable th, .twtable td, .twtable tr,.twtable caption {padding:3px;}
table.listView {font-size:0.85em; margin:0.8em 1.0em;}
table.listView th, table.listView td, table.listView tr {padding:0px 3px 0px 3px;}
.viewer pre {padding:0.5em; margin-left:0.5em; font-size:1.2em; line-height:1.4em; overflow:auto;}
.viewer code {font-size:1.2em; line-height:1.4em;}
.editor {font-size:1.1em;}
.editor input, .editor textarea {display:block; width:100%; font:inherit;}
.editorFooter {padding:0.25em 0em; font-size:.9em;}
.editorFooter .button {padding-top:0px; padding-bottom:0px;}
.fieldsetFix {border:0; padding:0; margin:1px 0px 1px 0px;}
.sparkline {line-height:1em;}
.sparktick {outline:0;}
.zoomer {font-size:1.1em; position:absolute; overflow:hidden;}
.zoomer div {padding:1em;}
* html #backstage {width:99%;}
* html #backstageArea {width:99%;}
#backstageArea {display:none; position:relative; overflow: hidden; z-index:150; padding:0.3em 0.5em 0.3em 0.5em;}
#backstageToolbar {position:relative;}
#backstageArea a {font-weight:bold; margin-left:0.5em; padding:0.3em 0.5em 0.3em 0.5em;}
#backstageButton {display:none; position:absolute; z-index:175; top:0em; right:0em;}
#backstageButton a {padding:0.1em 0.4em 0.1em 0.4em; margin:0.1em 0.1em 0.1em 0.1em;}
#backstage {position:relative; width:100%; z-index:50;}
#backstagePanel {display:none; z-index:100; position:absolute; width:90%; margin:0em 3em 0em 3em; padding:1em 1em 1em 1em;}
.backstagePanelFooter {padding-top:0.2em; float:right;}
.backstagePanelFooter a {padding:0.2em 0.4em 0.2em 0.4em;}
#backstageCloak {display:none; z-index:20; position:absolute; width:100%; height:100px;}
.whenBackstage {display:none;}
.backstageVisible .whenBackstage {display:block;}
/*}}}*/
/***
!Sections in this Tiddler:
*Generic rules
**Links styles
**Link Exceptions
*Header
*Main menu
*Sidebar
**Sidebar options
**Sidebar tabs
*Message area
*Popup
*Tabs
*Tiddler display
**Viewer
**Editor
*Misc. rules
!Generic Rules /%==============================================%/
***/
/*{{{*/
body {
font-size: .75em;
font-family: arial,helvetica;
position: relative;
margin: 0;
padding: 0;
}
h1,h2,h3,h4,h5 {
font-weight: bold;
text-decoration: none;
padding-left: 0.4em;
}
h1 {font-size: 1.5em;}
h2 {font-size: 1.25em;}
h3 {font-size: 1.1em;}
h4 {font-size: 1em;}
h5 {font-size: .9em;}
hr {
height: 1px;
}
a{
text-decoration: none;
}
ol { list-style-type: decimal }
ol ol { list-style-type: lower-alpha }
ol ol ol { list-style-type: lower-roman }
ol ol ol ol { list-style-type: decimal }
ol ol ol ol ol { list-style-type: lower-alpha }
ol ol ol ol ol ol { list-style-type: lower-roman }
ol ol ol ol ol ol ol { list-style-type: decimal }
/*}}}*/
/***
''General Link Styles'' /%-----------------------------------------------------------------------------%/
***/
/*{{{*/
.externalLink {
text-decoration: underline;
}
/* the 'a' is required for IE, otherwise it renders the whole tiddler a bold */
a.tiddlyLinkNonExisting.shadow {
font-weight: bold;
}
/*}}}*/
/***
''Exceptions to common link styles'' /%------------------------------------------------------------------%/
***/
/*{{{*/
#mainMenu .tiddlyLinkExisting,
#mainMenu .tiddlyLinkNonExisting,
#sidebarTabs .tiddlyLinkExisting,
#sidebarTabs .tiddlyLinkNonExisting{
font-weight: normal;
font-style: normal;
}
/*}}}*/
/***
!Header /%==================================================%/
***/
/*{{{*/
.header {
position: relative;
}
.header a:hover {
background: transparent;
}
.headerShadow {
position: relative;
padding: 4.5em 0em 1em 1em;
left: -1px;
top: -1px;
}
.headerForeground {
position: absolute;
padding: 4.5em 0em 1em 1em;
left: 0px;
top: 0px;
}
.siteTitle {
font-size: 3em;
}
.siteSubtitle {
font-size: 1.2em;
padding: 0em 0em 0em 2em;
}
/*}}}*/
/***
!Main menu /%==================================================%/
***/
/*{{{*/
#mainMenu {
position: absolute;
left: 0;
width: 10em;
text-align: right;
line-height: 1.6em;
padding: 1.5em 0.5em 0.5em 0.5em;
font-size: 1.1em;
}
/*}}}*/
/***
!Sidebar rules /%==================================================%/
***/
/*{{{*/
#sidebar {
position: absolute;
right: 3px;
width: 16em;
font-size: .9em;
}
/*}}}*/
/***
''Sidebar options'' /%----------------------------------------------------------------------------------%/
***/
/*{{{*/
#sidebarOptions {
padding-top: 0.3em;
}
#sidebarOptions a {
margin: 0em 0.2em;
padding: 0.2em 0.3em;
display: block;
}
#sidebarOptions input {
margin: 0.4em 0.5em;
}
#sidebarOptions .sliderPanel {
margin-left: 1em;
padding: 0.5em;
font-size: .85em;
}
#sidebarOptions .sliderPanel a {
font-weight: bold;
display: inline;
padding: 0;
}
#sidebarOptions .sliderPanel input {
margin: 0 0 .3em 0;
}
/*}}}*/
/***
''Sidebar tabs'' /%-------------------------------------------------------------------------------------%/
***/
/*{{{*/
#sidebarTabs .tabContents {
width: 15em;
overflow: hidden;
}
/*}}}*/
/***
!Message area /%==================================================%/
***/
/*{{{*/
#messageArea {
position:absolute; top:0; right:0; margin: 0.5em; padding: 0.5em;
}
*[id='messageArea'] {
position:fixed !important; z-index:99;}
.messageToolbar {
display: block;
text-align: right;
}
#messageArea a{
text-decoration: underline;
}
/*}}}*/
/***
!Popup /%==================================================%/
***/
/*{{{*/
.popup {
font-size: .9em;
padding: 0.2em;
list-style: none;
margin: 0;
}
.popup hr {
display: block;
height: 1px;
width: auto;
padding: 0;
margin: 0.2em 0em;
}
.popup li.disabled {
padding: 0.2em;
}
.popup li a{
display: block;
padding: 0.2em;
}
/*}}}*/
/***
!Tabs /%==================================================%/
***/
/*{{{*/
.tabset {
padding: 1em 0em 0em 0.5em;
}
.tab {
margin: 0em 0em 0em 0.25em;
padding: 2px;
}
.tabContents {
padding: 0.5em;
}
.tabContents ul, .tabContents ol {
margin: 0;
padding: 0;
}
.txtMainTab .tabContents li {
list-style: none;
}
.tabContents li.listLink {
margin-left: .75em;
}
/*}}}*/
/***
!Tiddler display rules /%==================================================%/
***/
/*{{{*/
#displayArea {
margin: 1em 17em 0em 14em;
}
.toolbar {
text-align: right;
font-size: .9em;
visibility: hidden;
}
.selected .toolbar {
visibility: visible;
}
.tiddler {
padding: 1em 1em 0em 1em;
}
.missing .viewer,.missing .title {
font-style: italic;
}
.title {
font-size: 1.6em;
font-weight: bold;
}
.missing .subtitle {
display: none;
}
.subtitle {
font-size: 0.8em;
}
/* I'm not a fan of how button looks in tiddlers... */
.tiddler .button {
padding: 0.2em 0.4em;
}
.tagging {
margin: 0.5em 0.5em 0.5em 0;
float: left;
display: none;
}
.isTag .tagging {
display: block;
}
.tagged {
margin: 0.5em;
float: right;
}
.tagging, .tagged {
font-size: 0.9em;
padding: 0.25em;
}
.tagging ul, .tagged ul {
list-style: none;margin: 0.25em;
padding: 0;
}
.tagClear {
clear: both;
}
.footer {
font-size: .9em;
}
.footer li {
display: inline;
}
/***
''The viewer is where the tiddler content is displayed'' /%------------------------------------------------%/
***/
/*{{{*/
* html .viewer pre {
width: 99%;
padding: 0 0 1em 0;
}
.viewer {
line-height: 1.4em;
padding-top: 0.5em;
}
.viewer .button {
margin: 0em 0.25em;
padding: 0em 0.25em;
}
.viewer blockquote {
line-height: 1.5em;
padding-left: 0.8em;
margin-left: 2.5em;
}
.viewer ul, .viewer ol{
margin-left: 0.5em;
padding-left: 1.5em;
}
.viewer table {
border-collapse: collapse;
margin: 0.8em 1.0em;
}
.viewer th, .viewer td, .viewer tr,.viewer caption{
padding: 3px;
}
.viewer pre {
padding: 0.5em;
margin-left: 0.5em;
font-size: 1.2em;
line-height: 1.4em;
overflow: auto;
}
.viewer code {
font-size: 1.2em;
line-height: 1.4em;
}
/*}}}*/
/***
''The editor replaces the viewer in the tiddler'' /%------------------------------------------------%/
***/
/*{{{*/
.editor {
font-size: 1.1em;
}
.editor input, .editor textarea {
display: block;
width: 100%;
font: inherit;
}
.editorFooter {
padding: 0.25em 0em;
font-size: .9em;
}
.editorFooter .button {
padding-top: 0px; padding-bottom: 0px;}
.fieldsetFix {border: 0;
padding: 0;
margin: 1px 0px 1px 0px;
}
/*}}}*/
/***
!Misc rules /%==================================================%/
***/
/*{{{*/
.sparkline {
line-height: 1em;
}
.sparktick {
outline: 0;
}
.zoomer {
font-size: 1.1em;
position: absolute;
padding: 1em;
}
.cascade {
font-size: 1.1em;
position: absolute;
overflow: hidden;
}
/*}}}*/
/*{{{*/
@media print {
#mainMenu, #sidebar, #messageArea, .toolbar, #backstageButton, #backstageArea, #toolbar, #topMenu, #rightMenu {display: none !important;}
#header, #headerShadow {display: none !important;}
.siteSubtitle {display: none !important;}
.siteTitle { font-size: 1.5em; }
#displayArea {margin: 1em 1em 0em;}
noscript {display:none;} /* Fixes a feature in Firefox 1.5.0.2 where print preview displays the noscript content */
}
/*}}}*/
Type the text for 'Styles'
<<tabs txtMainTab Timeline Timeline TabTimeline All 'All tiddlers' TabAll Tags 'All tags' TabTags More 'More lists' TabMore>>
The following command table should prove useful for this course. This is not an extensive list of commands you will need to know / become familiar with.
| ! Cover | ! Command | !Description |
|>|>|bgcolor(#a0ffa0): ''Basic Commands'' |
| x | echo |output command arguments to the terminal|
| x | cd |change directories|
| x | pwd |display current working directory|
| x | ls |list files|
| x | cp |copy files|
| x | rm |remove files|
| x | mv |move files|
| x | mkdir |create directory|
| x | rmdir |remove directory|
| x | touch |create an empty file with default permissions|
| x | ln |create link|
| x | man |view man pages|
| x | chmod |set permissions for a file|
| | chgrp |set group for a file|
|>|>|bgcolor(#a0ffa0): ''Display Text / Editors'' |
| x | less |display text output one page at a time|
| | pico |easy to use text editor|
| | nano |GNU clone of pico|
| x | vi |advanced unix text editor|
| | ex |line oriented version of vi|
| | vim |vi improved|
| x | vimtutor |learn how to use the vim editor|
|>|>|bgcolor(#a0ffa0): ''Filters'' |
| x | cat |concatenate and print files|
| x | grep |pattern matching filter|
| x | egrep |extended regular expression pattern matching filter|
| x | head |display first lines of a file|
| x | tail |display the last part of a file|
| x | cut |cut out selected portions of each line of a file|
| x | fold |fold long lines for finite width output device|
| x | sort |sort lines of text files|
| x | uniq |report or filter out repeated lines in a file|
| x | wc |word, line, character, and byte count|
| x | tr |translate characters|
| | paste |merge lines of input|
| | nl |line numbering filter|
| x | sed |stream editor|
| x | awk |pattern-directed scanning and processing language|
| x | tee |duplicate standard input to a file|
| | strings |print the strings of printable characters in (binary) files|
| | cmp |compare two files|
| | diff |compare files line by line|
| | comm |select or reject lines common to two files|
|>|>|bgcolor(#a0ffa0): ''System Commands'' |
| x | script |save copy of terminal session|
| | source |read a .file|
| x | rehash |recompute hash table of where commands are located|
| x | which |scan path for a program and return its location (or definition of an alias)|
| x | df |display free disk space|
| x | du |disk usage (-s display each file, -k 1K blocks , -h = human readable|
| x | find |walk a file hierarchy in search of files|
| | locate |find filenames quickly based on pre-generated file database|
| | hostname |print name of current host system|
| x | uptime |show how long system has been running|
| x | uname |display information about the system|
| | xargs |construct argument list(s) and execute utility|
| | quota |display disk usage and limits|
| | crontab |schedule commands for automated execution on regular intervals|
| | at |schedule a job for later execution|
|>|>|bgcolor(#a0ffa0): ''Process Management / Job Control'' |
| x | ps |process status|
| x | top |display and update information about the top cpu processes|
| x | kill |terminate or signal a process|
| x | jobs |display all jobs|
| x | fg |continue background jobs in the foreground|
| x | bg |continue suspended job in the background|
| x | stop |suspend job running in the background|
| | suspend |suspend the current running shell|
|>|>|bgcolor(#a0ffa0): ''User Information'' |
| x | w |display who is logged in and what they are doing|
| x | id |return user identity|
| x | groups |show group memberships|
| | users |list usernames of current logged in users|
| | who |display who is on the system|
| | whoami |display effective user id|
| x | finger |user information lookup program|
| x | last |indicate last logins of users and ttys|
|>|>|bgcolor(#a0ffa0): ''Misc commands useful for shell scripting'' |
| x | clear |clear the screen|
| x | read //var// |prompt the user to enter information, saving to //var//|
| x | date |display the current date and time with optional formatting. see strftime manpage|
| x | test |condition evaluation utility. Linked to [ See test manpage.|
| x | expr |evaluate an expression|
| x | jot |print sequential or random numbers|
| | sleep //n// |pause execution for //n// seconds|
| | stat |display extended file status/information|
| | stty |set the options for a terminal device interface|
| | basename |return the file name portion of a path|
| | dirname |return the directory name portion of a path|
| | fstat |List open files or determine whether specified file is open|
| x | exit [//n//] |log out or quit a script with the option exit status of //n//|
|>|>|bgcolor(#a0ffa0): ''Networking / Communication'' |
| x | ssh |~OpenSSH SSH client|
| x | scp |secure copy (remote file copy program)|
| | rsync |a fast, versatile, remote (and local) file-copying tool|
| | telnet |user interface to the TELNET protocol. also useful for testing connectivity to arbitrary ports|
| | talk / ytalk |talk to another user|
| | write |send a message to another user|
| | mesg |display (do not display) messages from other users|
| | host |DNS lookup utility|
| | nslookup |query Internet name servers interactively|
| | traceroute |print the route packets take to network host|
| | ping |send ICMP ~ECHO_REQUEST packets to network hosts|
| | lynx / links |character mode WWW browser|
|>|>|bgcolor(#a0ffa0): ''Text Formatting & Printing'' |
| x | lpr |command line print utility|
| x | lpq |print spool queue examination program|
| x | lprm |remove jobs from the line printer spooling queue|
| x | pdf2ps |Ghostscript PDF to ~PostScript translator|
| x | a2ps |format files for printing on a ~PostScript printer|
|>|>|bgcolor(#a0ffa0): ''Working with files'' |
| x | file |display file type|
| x | tar |manipulate file archive files|
| x | gzip |compression tool using ~Lempel-Ziv coding|
| x | gunzip |decompression tool using ~Lempel-Ziv coding|
| x | bzip2 |a block-sorting file compressor|
| x | bunzip2 |a block-sorting file decompressor|
| | split |split a file into pieces|
| x | md5 / md5sum |calculate a message-digest fingerprint (checksum) for a file (freebsd / linux)|
| | srm |securely remove files or directories|
| | rsync |a fast, versatile, remote (and local) file-copying tool|
/***
|Name|TagglyListPlugin|
|Created by|SimonBaird|
|Location|http://simonbaird.com/mptw/#TagglyListPlugin|
|Version|1.1.2 25-Apr-06|
|Requires|See TagglyTagging|
!History
* 1.1.2 (25-Apr-2006) embedded TagglyTaggingStyles. No longer need separated tiddler for styles.
* 1.1.1 (6-Mar-2006) fixed bug with refreshAllVisible closing tiddlers being edited. Thanks Luke Blanshard.
***/
/***
!Setup and config
***/
//{{{
version.extensions.TagglyListPlugin = {
major: 1, minor: 1, revision: 2,
date: new Date(2006,4,25),
source: "http://simonbaird.com/mptw/#TagglyListPlugin"
};
config.macros.tagglyList = {};
config.macros.tagglyListByTag = {};
config.macros.tagglyListControl = {};
config.macros.tagglyListWithSort = {};
config.macros.hideSomeTags = {};
// change this to your preference
config.macros.tagglyListWithSort.maxCols = 6;
config.macros.tagglyList.label = "Tagged as %0:";
// the default sort options. set these to your preference
config.macros.tagglyListWithSort.defaults = {
sortBy:"title", // title|created|modified
sortOrder: "asc", // asc|desc
hideState: "show", // show|hide
groupState: "nogroup", // nogroup|group
numCols: 1
};
// these tags will be ignored by the grouped view
config.macros.tagglyListByTag.excludeTheseTags = [
"systemConfig",
"TiddlerTemplates"
];
config.macros.tagglyListControl.tags = {
title:"sortByTitle",
modified: "sortByModified",
created: "sortByCreated",
asc:"sortAsc",
desc:"sortDesc",
hide:"hideTagged",
show:"showTagged",
nogroup:"noGroupByTag",
group:"groupByTag",
cols1:"list1Cols",
cols2:"list2Cols",
cols3:"list3Cols",
cols4:"list4Cols",
cols5:"list5Cols",
cols6:"list6Cols",
cols7:"list7Cols",
cols8:"list8Cols",
cols9:"list9Cols"
}
// note: should match config.macros.tagglyListControl.tags
config.macros.hideSomeTags.tagsToHide = [
"sortByTitle",
"sortByCreated",
"sortByModified",
"sortDesc",
"sortAsc",
"hideTagged",
"showTagged",
"noGroupByTag",
"groupByTag",
"list1Cols",
"list2Cols",
"list3Cols",
"list4Cols",
"list5Cols",
"list6Cols",
"list7Cols",
"list8Cols",
"list9Cols"
];
//}}}
/***
!Utils
***/
//{{{
// from Eric
function isTagged(title,tag) {
var t=store.getTiddler(title); if (!t) return false;
return (t.tags.find(tag)!=null);
}
// from Eric
function toggleTag(title,tag) {
var t=store.getTiddler(title); if (!t || !t.tags) return;
if (t.tags.find(tag)==null) t.tags.push(tag);
else t.tags.splice(t.tags.find(tag),1);
}
function addTag(title,tag) {
var t=store.getTiddler(title); if (!t || !t.tags) return;
t.tags.push(tag);
}
function removeTag(title,tag) {
var t=store.getTiddler(title); if (!t || !t.tags) return;
if (t.tags.find(tag)!=null) t.tags.splice(t.tags.find(tag),1);
}
// from Udo
Array.prototype.indexOf = function(item) {
for (var i = 0; i < this.length; i++) {
if (this[i] == item) {
return i;
}
}
return -1;
};
Array.prototype.contains = function(item) {
return (this.indexOf(item) >= 0);
}
//}}}
/***
!tagglyList
displays a list of tagged tiddlers.
parameters are sortField and sortOrder
***/
//{{{
// not used at the moment...
function sortedListOfOtherTags(tiddler,thisTag) {
var list = tiddler.tags.concat(); // so we are working on a clone..
for (var i=0;i<config.macros.hideSomeTags.tagsToHide.length;i++) {
if (list.find(config.macros.hideSomeTags.tagsToHide[i]) != null)
list.splice(list.find(config.macros.hideSomeTags.tagsToHide[i]),1); // remove hidden ones
}
for (var i=0;i<config.macros.tagglyListByTag.excludeTheseTags.length;i++) {
if (list.find(config.macros.tagglyListByTag.excludeTheseTags[i]) != null)
list.splice(list.find(config.macros.tagglyListByTag.excludeTheseTags[i]),1); // remove excluded ones
}
list.splice(list.find(thisTag),1); // remove thisTag
return '[[' + list.sort().join("]] [[") + ']]';
}
function sortHelper(a,b) {
if (a == b) return 0;
else if (a < b) return -1;
else return +1;
}
config.macros.tagglyListByTag.handler = function (place,macroName,params,wikifier,paramString,tiddler) {
var sortBy = params[0] ? params[0] : "title";
var sortOrder = params[1] ? params[1] : "asc";
var result = store.getTaggedTiddlers(tiddler.title,sortBy);
if (sortOrder == "desc")
result = result.reverse();
var leftOvers = []
for (var i=0;i<result.length;i++) {
leftOvers.push(result[i].title);
}
var allTagsHolder = {};
for (var i=0;i<result.length;i++) {
for (var j=0;j<result[i].tags.length;j++) {
if (
result[i].tags[j] != tiddler.title // not this tiddler
&& config.macros.hideSomeTags.tagsToHide.find(result[i].tags[j]) == null // not a hidden one
&& config.macros.tagglyListByTag.excludeTheseTags.find(result[i].tags[j]) == null // not excluded
) {
if (!allTagsHolder[result[i].tags[j]])
allTagsHolder[result[i].tags[j]] = "";
allTagsHolder[result[i].tags[j]] += "**[["+result[i].title+"]]\n";
if (leftOvers.find(result[i].title) != null)
leftOvers.splice(leftOvers.find(result[i].title),1); // remove from leftovers. at the end it will contain the leftovers...
}
}
}
var allTags = [];
for (var t in allTagsHolder)
allTags.push(t);
allTags.sort(function(a,b) {
var tidA = store.getTiddler(a);
var tidB = store.getTiddler(b);
if (sortBy == "title") return sortHelper(a,b);
else if (!tidA && !tidB) return 0;
else if (!tidA) return -1;
else if (!tidB) return +1;
else return sortHelper(tidA[sortBy],tidB[sortBy]);
});
var markup = "";
if (sortOrder == "desc") {
allTags.reverse();
}
else {
// leftovers first...
for (var i=0;i<leftOvers.length;i++)
markup += "*[["+leftOvers[i]+"]]\n";
}
for (var i=0;i<allTags.length;i++)
markup += "*[["+allTags[i]+"]]\n" + allTagsHolder[allTags[i]];
if (sortOrder == "desc") {
// leftovers last...
for (var i=0;i<leftOvers.length;i++)
markup += "*[["+leftOvers[i]+"]]\n";
}
wikify(markup,place);
}
config.macros.tagglyList.handler = function (place,macroName,params,wikifier,paramString,tiddler) {
var sortBy = params[0] ? params[0] : "title";
var sortOrder = params[1] ? params[1] : "asc";
var numCols = params[2] ? params[2] : 1;
var result = store.getTaggedTiddlers(tiddler.title,sortBy);
if (sortOrder == "desc")
result = result.reverse();
var listSize = result.length;
var colSize = listSize/numCols;
var remainder = listSize % numCols;
var upperColsize;
var lowerColsize;
if (colSize != Math.floor(colSize)) {
// it's not an exact fit so..
lowerColsize = Math.floor(colSize);
upperColsize = Math.floor(colSize) + 1;
}
else {
lowerColsize = colSize;
upperColsize = colSize;
}
var markup = "";
var c=0;
var newTaggedTable = createTiddlyElement(place,"table");
var newTaggedBody = createTiddlyElement(newTaggedTable,"tbody");
var newTaggedTr = createTiddlyElement(newTaggedBody,"tr");
for (var j=0;j<numCols;j++) {
var foo = "";
var thisSize;
if (j<remainder)
thisSize = upperColsize;
else
thisSize = lowerColsize;
for (var i=0;i<thisSize;i++)
foo += ( "*[[" + result[c++].title + "]]\n"); // was using splitList.shift() but didn't work in IE;
var newTd = createTiddlyElement(newTaggedTr,"td",null,"tagglyTagging");
wikify(foo,newTd);
}
};
/* snip for later.....
//var groupBy = params[3] ? params[3] : "t.title.substr(0,1)";
//var groupBy = params[3] ? params[3] : "sortedListOfOtherTags(t,tiddler.title)";
//var groupBy = params[3] ? params[3] : "t.modified";
var groupBy = null; // for now. groupBy here is working but disabled for now.
var prevGroup = "";
var thisGroup = "";
if (groupBy) {
result.sort(function(a,b) {
var t = a; var aSortVal = eval(groupBy); var aSortVal2 = eval("t".sortBy);
var t = b; var bSortVal = eval(groupBy); var bSortVal2 = eval("t".sortBy);
var t = b; var bSortVal2 = eval(groupBy);
return (aSortVal == bSortVal ?
(aSortVal2 == bSortVal2 ? 0 : (aSortVal2 < bSortVal2 ? -1 : +1)) // yuck
: (aSortVal < bSortVal ? -1 : +1));
});
}
if (groupBy) {
thisGroup = eval(groupBy);
if (thisGroup != prevGroup)
markup += "*[["+thisGroup+']]\n';
markup += "**[["+t.title+']]\n';
prevGroup = thisGroup;
}
*/
//}}}
/***
!tagglyListControl
Use to make the sort control buttons
***/
//{{{
function getSortBy(title) {
var tiddler = store.getTiddler(title);
var defaultVal = config.macros.tagglyListWithSort.defaults.sortBy;
if (!tiddler) return defaultVal;
var usetags = config.macros.tagglyListControl.tags;
if (tiddler.tags.contains(usetags["title"])) return "title";
else if (tiddler.tags.contains(usetags["modified"])) return "modified";
else if (tiddler.tags.contains(usetags["created"])) return "created";
else return defaultVal;
}
function getSortOrder(title) {
var tiddler = store.getTiddler(title);
var defaultVal = config.macros.tagglyListWithSort.defaults.sortOrder;
if (!tiddler) return defaultVal;
var usetags = config.macros.tagglyListControl.tags;
if (tiddler.tags.contains(usetags["asc"])) return "asc";
else if (tiddler.tags.contains(usetags["desc"])) return "desc";
else return defaultVal;
}
function getHideState(title) {
var tiddler = store.getTiddler(title);
var defaultVal = config.macros.tagglyListWithSort.defaults.hideState;
if (!tiddler) return defaultVal;
var usetags = config.macros.tagglyListControl.tags;
if (tiddler.tags.contains(usetags["hide"])) return "hide";
else if (tiddler.tags.contains(usetags["show"])) return "show";
else return defaultVal;
}
function getGroupState(title) {
var tiddler = store.getTiddler(title);
var defaultVal = config.macros.tagglyListWithSort.defaults.groupState;
if (!tiddler) return defaultVal;
var usetags = config.macros.tagglyListControl.tags;
if (tiddler.tags.contains(usetags["group"])) return "group";
else if (tiddler.tags.contains(usetags["nogroup"])) return "nogroup";
else return defaultVal;
}
function getNumCols(title) {
var tiddler = store.getTiddler(title);
var defaultVal = config.macros.tagglyListWithSort.defaults.numCols; // an int
if (!tiddler) return defaultVal;
var usetags = config.macros.tagglyListControl.tags;
for (var i=1;i<=config.macros.tagglyListWithSort.maxCols;i++)
if (tiddler.tags.contains(usetags["cols"+i])) return i;
return defaultVal;
}
function getSortLabel(title,which) {
// TODO. the strings here should be definable in config
var by = getSortBy(title);
var order = getSortOrder(title);
var hide = getHideState(title);
var group = getGroupState(title);
if (which == "hide") return (hide == "show" ? "−" : "+"); // 0x25b8;
else if (which == "group") return (group == "group" ? "normal" : "grouped");
else if (which == "cols") return "cols±"; // ±
else if (by == which) return which + (order == "asc" ? "↓" : "↑"); // ↑ ↓
else return which;
}
function handleSortClick(title,which) {
var currentSortBy = getSortBy(title);
var currentSortOrder = getSortOrder(title);
var currentHideState = getHideState(title);
var currentGroupState = getGroupState(title);
var currentNumCols = getNumCols(title);
var tags = config.macros.tagglyListControl.tags;
// if it doesn't exist, lets create it..
if (!store.getTiddler(title))
store.saveTiddler(title,title,"",config.options.txtUserName,new Date(),null);
if (which == "hide") {
// toggle hide state
var newHideState = (currentHideState == "hide" ? "show" : "hide");
removeTag(title,tags[currentHideState]);
if (newHideState != config.macros.tagglyListWithSort.defaults.hideState)
toggleTag(title,tags[newHideState]);
}
else if (which == "group") {
// toggle hide state
var newGroupState = (currentGroupState == "group" ? "nogroup" : "group");
removeTag(title,tags[currentGroupState]);
if (newGroupState != config.macros.tagglyListWithSort.defaults.groupState)
toggleTag(title,tags[newGroupState]);
}
else if (which == "cols") {
// toggle num cols
var newNumCols = currentNumCols + 1; // confusing. currentNumCols is an int
if (newNumCols > config.macros.tagglyListWithSort.maxCols || newNumCols > store.getTaggedTiddlers(title).length)
newNumCols = 1;
removeTag(title,tags["cols"+currentNumCols]);
if (("cols"+newNumCols) != config.macros.tagglyListWithSort.defaults.groupState)
toggleTag(title,tags["cols"+newNumCols]);
}
else if (currentSortBy == which) {
// toggle sort order
var newSortOrder = (currentSortOrder == "asc" ? "desc" : "asc");
removeTag(title,tags[currentSortOrder]);
if (newSortOrder != config.macros.tagglyListWithSort.defaults.sortOrder)
toggleTag(title,tags[newSortOrder]);
}
else {
// change sortBy only
removeTag(title,tags["title"]);
removeTag(title,tags["created"]);
removeTag(title,tags["modified"]);
if (which != config.macros.tagglyListWithSort.defaults.sortBy)
toggleTag(title,tags[which]);
}
store.setDirty(true); // save is required now.
story.refreshTiddler(title,false,true); // force=true
}
config.macros.tagglyListControl.handler = function (place,macroName,params,wikifier,paramString,tiddler) {
var onclick = function(e) {
if (!e) var e = window.event;
handleSortClick(tiddler.title,params[0]);
e.cancelBubble = true;
if (e.stopPropagation) e.stopPropagation();
return false;
};
createTiddlyButton(place,getSortLabel(tiddler.title,params[0]),"Click to change sort options",onclick,params[0]=="hide"?"hidebutton":"button");
}
//}}}
/***
!tagglyListWithSort
put it all together..
***/
//{{{
config.macros.tagglyListWithSort.handler = function (place,macroName,params,wikifier,paramString,tiddler) {
if (tiddler && store.getTaggedTiddlers(tiddler.title).length > 0)
// todo make this readable
wikify(
"<<tagglyListControl hide>>"+
(getHideState(tiddler.title) != "hide" ?
'<html><span class="tagglyLabel">'+config.macros.tagglyList.label.format([tiddler.title])+' </span></html>'+
"<<tagglyListControl title>><<tagglyListControl modified>><<tagglyListControl created>><<tagglyListControl group>>"+(getGroupState(tiddler.title)=="group"?"":"<<tagglyListControl cols>>")+"\n" +
"<<tagglyList" + (getGroupState(tiddler.title)=="group"?"ByTag ":" ") + getSortBy(tiddler.title)+" "+getSortOrder(tiddler.title)+" "+getNumCols(tiddler.title)+">>" // hacky
// + \n----\n" +
//"<<tagglyList "+getSortBy(tiddler.title)+" "+getSortOrder(tiddler.title)+">>"
: ""),
place,null,tiddler);
}
config.macros.tagglyTagging = { handler: config.macros.tagglyListWithSort.handler };
//}}}
/***
!hideSomeTags
So we don't see the sort tags.
(note, they are still there when you edit. Will that be too annoying?
***/
//{{{
// based on tags.handler
config.macros.hideSomeTags.handler = function(place,macroName,params,wikifier,paramString,tiddler) {
var theList = createTiddlyElement(place,"ul");
if(params[0] && store.tiddlerExists[params[0]])
tiddler = store.getTiddler(params[0]);
var lingo = config.views.wikified.tag;
var prompt = tiddler.tags.length == 0 ? lingo.labelNoTags : lingo.labelTags;
createTiddlyElement(theList,"li",null,"listTitle",prompt.format([tiddler.title]));
for(var t=0; t<tiddler.tags.length; t++)
if (!this.tagsToHide.contains(tiddler.tags[t])) // this is the only difference from tags.handler...
createTagButton(createTiddlyElement(theList,"li"),tiddler.tags[t],tiddler.title);
}
//}}}
/***
!Refresh everything when we save a tiddler. So the tagged lists never get stale. Is this too slow???
***/
//{{{
function refreshAllVisible() {
story.forEachTiddler(function(title,element) {
if (element.getAttribute("dirty") != "true")
story.refreshTiddler(title,false,true);
});
}
story.saveTiddler_orig_mptw = story.saveTiddler;
story.saveTiddler = function(title,minorUpdate) {
var result = this.saveTiddler_orig_mptw(title,minorUpdate);
// refreshAllVisible();
return result;
}
store.removeTiddler_orig_mptw = store.removeTiddler;
store.removeTiddler = function(title) {
this.removeTiddler_orig_mptw(title);
// refreshAllVisible();
}
config.shadowTiddlers.TagglyTaggingStyles = "/***\nTo use, add {{{[[TagglyTaggingStyles]]}}} to your StyleSheet tiddler, or you can just paste the CSS in directly. See also ViewTemplate, EditTemplate and TagglyTagging.\n***/\n/*{{{*/\n.tagglyTagged li.listTitle { display:none;}\n.tagglyTagged li { display: inline; font-size:90%; }\n.tagglyTagged ul { margin:0px; padding:0px; }\n.tagglyTagging { padding-top:0.5em; }\n.tagglyTagging li.listTitle { display:none;}\n.tagglyTagging ul { margin-top:0px; padding-top:0.5em; padding-left:2em; margin-bottom:0px; padding-bottom:0px; }\n\n/* .tagglyTagging .tghide { display:inline; } */\n\n.tagglyTagging { vertical-align: top; margin:0px; padding:0px; }\n.tagglyTagging table { margin:0px; padding:0px; }\n\n\n.tagglyTagging .button { display:none; margin-left:3px; margin-right:3px; }\n.tagglyTagging .button, .tagglyTagging .hidebutton { color:#aaa; font-size:90%; border:0px; padding-left:0.3em;padding-right:0.3em;}\n.tagglyTagging .button:hover, .hidebutton:hover { background:#eee; color:#888; }\n.selected .tagglyTagging .button { display:inline; }\n\n.tagglyTagging .hidebutton { color:white; } /* has to be there so it takes up space. tweak if you're not using a white tiddler bg */\n.selected .tagglyTagging .hidebutton { color:#aaa }\n\n.tagglyLabel { color:#aaa; font-size:90%; }\n\n.tagglyTagging ul {padding-top:0px; padding-bottom:0.5em; margin-left:1em; }\n.tagglyTagging ul ul {list-style-type:disc; margin-left:-1em;}\n.tagglyTagging ul ul li {margin-left:0.5em; }\n\n.editLabel { font-size:90%; padding-top:0.5em; }\n/*}}}*/\n";
refreshStyles("TagglyTaggingStyles");
//}}}
// // <html>▸▾−±</html>
Type the text for 'TagglyTagging'
/***
|Name:|TagglyTaggingPlugin|
|Description:|tagglyTagging macro is a replacement for the builtin tagging macro in your ViewTemplate|
|Version:|3.3.1 ($Rev: 6100 $)|
|Date:|$Date: 2008-07-27 01:42:07 +1000 (Sun, 27 Jul 2008) $|
|Source:|http://mptw.tiddlyspot.com/#TagglyTaggingPlugin|
|Author:|Simon Baird <simon.baird@gmail.com>|
|License:|http://mptw.tiddlyspot.com/#TheBSDLicense|
!Notes
See http://mptw.tiddlyspot.com/#TagglyTagging
***/
//{{{
merge(String.prototype,{
parseTagExpr: function(debug) {
if (this.trim() == "")
return "(true)";
var anyLogicOp = /(!|&&|\|\||\(|\))/g;
var singleLogicOp = /^(!|&&|\|\||\(|\))$/;
var spaced = this.
// because square brackets in templates are no good
// this means you can use [(With Spaces)] instead of [[With Spaces]]
replace(/\[\(/g," [[").
replace(/\)\]/g,"]] ").
// space things out so we can use readBracketedList. tricky eh?
replace(anyLogicOp," $1 ");
var expr = "";
var tokens = spaced.readBracketedList(false); // false means don't uniq the list. nice one JR!
for (var i=0;i<tokens.length;i++)
if (tokens[i].match(singleLogicOp))
expr += tokens[i];
else
expr += "tiddler.tags.contains('%0')".format([tokens[i].replace(/'/,"\\'")]); // fix single quote bug. still have round bracket bug i think
if (debug)
alert(expr);
return '('+expr+')';
}
});
merge(TiddlyWiki.prototype,{
getTiddlersByTagExpr: function(tagExpr,sortField) {
var result = [];
var expr = tagExpr.parseTagExpr();
store.forEachTiddler(function(title,tiddler) {
if (eval(expr))
result.push(tiddler);
});
if(!sortField)
sortField = "title";
result.sort(function(a,b) {return a[sortField] < b[sortField] ? -1 : (a[sortField] == b[sortField] ? 0 : +1);});
return result;
}
});
config.taggly = {
// for translations
lingo: {
labels: {
asc: "\u2191", // down arrow
desc: "\u2193", // up arrow
title: "title",
modified: "modified",
created: "created",
show: "+",
hide: "-",
normal: "normal",
group: "group",
commas: "commas",
sitemap: "sitemap",
numCols: "cols\u00b1", // plus minus sign
label: "Tagged as '%0':",
exprLabel: "Matching tag expression '%0':",
excerpts: "excerpts",
descr: "descr",
slices: "slices",
contents: "contents",
sliders: "sliders",
noexcerpts: "title only",
noneFound: "(none)"
},
tooltips: {
title: "Click to sort by title",
modified: "Click to sort by modified date",
created: "Click to sort by created date",
show: "Click to show tagging list",
hide: "Click to hide tagging list",
normal: "Click to show a normal ungrouped list",
group: "Click to show list grouped by tag",
sitemap: "Click to show a sitemap style list",
commas: "Click to show a comma separated list",
numCols: "Click to change number of columns",
excerpts: "Click to show excerpts",
descr: "Click to show the description slice",
slices: "Click to show all slices",
contents: "Click to show entire tiddler contents",
sliders: "Click to show tiddler contents in sliders",
noexcerpts: "Click to show entire title only"
},
tooDeepMessage: "* //sitemap too deep...//"
},
config: {
showTaggingCounts: true,
listOpts: {
// the first one will be the default
sortBy: ["title","modified","created"],
sortOrder: ["asc","desc"],
hideState: ["show","hide"],
listMode: ["normal","group","sitemap","commas"],
numCols: ["1","2","3","4","5","6"],
excerpts: ["noexcerpts","excerpts","descr","slices","contents","sliders"]
},
valuePrefix: "taggly.",
excludeTags: ["excludeLists","excludeTagging"],
excerptSize: 50,
excerptMarker: "/%"+"%/",
siteMapDepthLimit: 25
},
getTagglyOpt: function(title,opt) {
var val = store.getValue(title,this.config.valuePrefix+opt);
return val ? val : this.config.listOpts[opt][0];
},
setTagglyOpt: function(title,opt,value) {
if (!store.tiddlerExists(title))
// create it silently
store.saveTiddler(title,title,config.views.editor.defaultText.format([title]),config.options.txtUserName,new Date(),"");
// if value is default then remove it to save space
return store.setValue(title,
this.config.valuePrefix+opt,
value == this.config.listOpts[opt][0] ? null : value);
},
getNextValue: function(title,opt) {
var current = this.getTagglyOpt(title,opt);
var pos = this.config.listOpts[opt].indexOf(current);
// a little usability enhancement. actually it doesn't work right for grouped or sitemap
var limit = (opt == "numCols" ? store.getTiddlersByTagExpr(title).length : this.config.listOpts[opt].length);
var newPos = (pos + 1) % limit;
return this.config.listOpts[opt][newPos];
},
toggleTagglyOpt: function(title,opt) {
var newVal = this.getNextValue(title,opt);
this.setTagglyOpt(title,opt,newVal);
},
createListControl: function(place,title,type) {
var lingo = config.taggly.lingo;
var label;
var tooltip;
var onclick;
if ((type == "title" || type == "modified" || type == "created")) {
// "special" controls. a little tricky. derived from sortOrder and sortBy
label = lingo.labels[type];
tooltip = lingo.tooltips[type];
if (this.getTagglyOpt(title,"sortBy") == type) {
label += lingo.labels[this.getTagglyOpt(title,"sortOrder")];
onclick = function() {
config.taggly.toggleTagglyOpt(title,"sortOrder");
return false;
}
}
else {
onclick = function() {
config.taggly.setTagglyOpt(title,"sortBy",type);
config.taggly.setTagglyOpt(title,"sortOrder",config.taggly.config.listOpts.sortOrder[0]);
return false;
}
}
}
else {
// "regular" controls, nice and simple
label = lingo.labels[type == "numCols" ? type : this.getNextValue(title,type)];
tooltip = lingo.tooltips[type == "numCols" ? type : this.getNextValue(title,type)];
onclick = function() {
config.taggly.toggleTagglyOpt(title,type);
return false;
}
}
// hide button because commas don't have columns
if (!(this.getTagglyOpt(title,"listMode") == "commas" && type == "numCols"))
createTiddlyButton(place,label,tooltip,onclick,type == "hideState" ? "hidebutton" : "button");
},
makeColumns: function(orig,numCols) {
var listSize = orig.length;
var colSize = listSize/numCols;
var remainder = listSize % numCols;
var upperColsize = colSize;
var lowerColsize = colSize;
if (colSize != Math.floor(colSize)) {
// it's not an exact fit so..
upperColsize = Math.floor(colSize) + 1;
lowerColsize = Math.floor(colSize);
}
var output = [];
var c = 0;
for (var j=0;j<numCols;j++) {
var singleCol = [];
var thisSize = j < remainder ? upperColsize : lowerColsize;
for (var i=0;i<thisSize;i++)
singleCol.push(orig[c++]);
output.push(singleCol);
}
return output;
},
drawTable: function(place,columns,theClass) {
var newTable = createTiddlyElement(place,"table",null,theClass);
var newTbody = createTiddlyElement(newTable,"tbody");
var newTr = createTiddlyElement(newTbody,"tr");
for (var j=0;j<columns.length;j++) {
var colOutput = "";
for (var i=0;i<columns[j].length;i++)
colOutput += columns[j][i];
var newTd = createTiddlyElement(newTr,"td",null,"tagglyTagging"); // todo should not need this class
wikify(colOutput,newTd);
}
return newTable;
},
createTagglyList: function(place,title,isTagExpr) {
switch(this.getTagglyOpt(title,"listMode")) {
case "group": return this.createTagglyListGrouped(place,title,isTagExpr); break;
case "normal": return this.createTagglyListNormal(place,title,false,isTagExpr); break;
case "commas": return this.createTagglyListNormal(place,title,true,isTagExpr); break;
case "sitemap":return this.createTagglyListSiteMap(place,title,isTagExpr); break;
}
},
getTaggingCount: function(title,isTagExpr) {
// thanks to Doug Edmunds
if (this.config.showTaggingCounts) {
var tagCount = config.taggly.getTiddlers(title,'title',isTagExpr).length;
if (tagCount > 0)
return " ("+tagCount+")";
}
return "";
},
getTiddlers: function(titleOrExpr,sortBy,isTagExpr) {
return isTagExpr ? store.getTiddlersByTagExpr(titleOrExpr,sortBy) : store.getTaggedTiddlers(titleOrExpr,sortBy);
},
getExcerpt: function(inTiddlerTitle,title,indent) {
if (!indent)
indent = 1;
var displayMode = this.getTagglyOpt(inTiddlerTitle,"excerpts");
var t = store.getTiddler(title);
if (t && displayMode == "excerpts") {
var text = t.text.replace(/\n/," ");
var marker = text.indexOf(this.config.excerptMarker);
if (marker != -1) {
return " {{excerpt{<nowiki>" + text.substr(0,marker) + "</nowiki>}}}";
}
else if (text.length < this.config.excerptSize) {
return " {{excerpt{<nowiki>" + t.text + "</nowiki>}}}";
}
else {
return " {{excerpt{<nowiki>" + t.text.substr(0,this.config.excerptSize) + "..." + "</nowiki>}}}";
}
}
else if (t && displayMode == "contents") {
return "\n{{contents indent"+indent+"{\n" + t.text + "\n}}}";
}
else if (t && displayMode == "sliders") {
return "<slider slide>\n{{contents{\n" + t.text + "\n}}}\n</slider>";
}
else if (t && displayMode == "descr") {
var descr = store.getTiddlerSlice(title,'Description');
return descr ? " {{excerpt{" + descr + "}}}" : "";
}
else if (t && displayMode == "slices") {
var result = "";
var slices = store.calcAllSlices(title);
for (var s in slices)
result += "|%0|<nowiki>%1</nowiki>|\n".format([s,slices[s]]);
return result ? "\n{{excerpt excerptIndent{\n" + result + "}}}" : "";
}
return "";
},
notHidden: function(t,inTiddler) {
if (typeof t == "string")
t = store.getTiddler(t);
return (!t || !t.tags.containsAny(this.config.excludeTags) ||
(inTiddler && this.config.excludeTags.contains(inTiddler)));
},
// this is for normal and commas mode
createTagglyListNormal: function(place,title,useCommas,isTagExpr) {
var list = config.taggly.getTiddlers(title,this.getTagglyOpt(title,"sortBy"),isTagExpr);
if (this.getTagglyOpt(title,"sortOrder") == "desc")
list = list.reverse();
var output = [];
var first = true;
for (var i=0;i<list.length;i++) {
if (this.notHidden(list[i],title)) {
var countString = this.getTaggingCount(list[i].title);
var excerpt = this.getExcerpt(title,list[i].title);
if (useCommas)
output.push((first ? "" : ", ") + "[[" + list[i].title + "]]" + countString + excerpt);
else
output.push("*[[" + list[i].title + "]]" + countString + excerpt + "\n");
first = false;
}
}
return this.drawTable(place,
this.makeColumns(output,useCommas ? 1 : parseInt(this.getTagglyOpt(title,"numCols"))),
useCommas ? "commas" : "normal");
},
// this is for the "grouped" mode
createTagglyListGrouped: function(place,title,isTagExpr) {
var sortBy = this.getTagglyOpt(title,"sortBy");
var sortOrder = this.getTagglyOpt(title,"sortOrder");
var list = config.taggly.getTiddlers(title,sortBy,isTagExpr);
if (sortOrder == "desc")
list = list.reverse();
var leftOvers = []
for (var i=0;i<list.length;i++)
leftOvers.push(list[i].title);
var allTagsHolder = {};
for (var i=0;i<list.length;i++) {
for (var j=0;j<list[i].tags.length;j++) {
if (list[i].tags[j] != title) { // not this tiddler
if (this.notHidden(list[i].tags[j],title)) {
if (!allTagsHolder[list[i].tags[j]])
allTagsHolder[list[i].tags[j]] = "";
if (this.notHidden(list[i],title)) {
allTagsHolder[list[i].tags[j]] += "**[["+list[i].title+"]]"
+ this.getTaggingCount(list[i].title) + this.getExcerpt(title,list[i].title) + "\n";
leftOvers.setItem(list[i].title,-1); // remove from leftovers. at the end it will contain the leftovers
}
}
}
}
}
var allTags = [];
for (var t in allTagsHolder)
allTags.push(t);
var sortHelper = function(a,b) {
if (a == b) return 0;
if (a < b) return -1;
return 1;
};
allTags.sort(function(a,b) {
var tidA = store.getTiddler(a);
var tidB = store.getTiddler(b);
if (sortBy == "title") return sortHelper(a,b);
else if (!tidA && !tidB) return 0;
else if (!tidA) return -1;
else if (!tidB) return +1;
else return sortHelper(tidA[sortBy],tidB[sortBy]);
});
var leftOverOutput = "";
for (var i=0;i<leftOvers.length;i++)
if (this.notHidden(leftOvers[i],title))
leftOverOutput += "*[["+leftOvers[i]+"]]" + this.getTaggingCount(leftOvers[i]) + this.getExcerpt(title,leftOvers[i]) + "\n";
var output = [];
if (sortOrder == "desc")
allTags.reverse();
else if (leftOverOutput != "")
// leftovers first...
output.push(leftOverOutput);
for (var i=0;i<allTags.length;i++)
if (allTagsHolder[allTags[i]] != "")
output.push("*[["+allTags[i]+"]]" + this.getTaggingCount(allTags[i]) + this.getExcerpt(title,allTags[i]) + "\n" + allTagsHolder[allTags[i]]);
if (sortOrder == "desc" && leftOverOutput != "")
// leftovers last...
output.push(leftOverOutput);
return this.drawTable(place,
this.makeColumns(output,parseInt(this.getTagglyOpt(title,"numCols"))),
"grouped");
},
// used to build site map
treeTraverse: function(title,depth,sortBy,sortOrder,isTagExpr) {
var list = config.taggly.getTiddlers(title,sortBy,isTagExpr);
if (sortOrder == "desc")
list.reverse();
var indent = "";
for (var j=0;j<depth;j++)
indent += "*"
var childOutput = "";
if (depth > this.config.siteMapDepthLimit)
childOutput += indent + this.lingo.tooDeepMessage;
else
for (var i=0;i<list.length;i++)
if (list[i].title != title)
if (this.notHidden(list[i].title,this.config.inTiddler))
childOutput += this.treeTraverse(list[i].title,depth+1,sortBy,sortOrder,false);
if (depth == 0)
return childOutput;
else
return indent + "[["+title+"]]" + this.getTaggingCount(title) + this.getExcerpt(this.config.inTiddler,title,depth) + "\n" + childOutput;
},
// this if for the site map mode
createTagglyListSiteMap: function(place,title,isTagExpr) {
this.config.inTiddler = title; // nasty. should pass it in to traverse probably
var output = this.treeTraverse(title,0,this.getTagglyOpt(title,"sortBy"),this.getTagglyOpt(title,"sortOrder"),isTagExpr);
return this.drawTable(place,
this.makeColumns(output.split(/(?=^\*\[)/m),parseInt(this.getTagglyOpt(title,"numCols"))), // regexp magic
"sitemap"
);
},
macros: {
tagglyTagging: {
handler: function (place,macroName,params,wikifier,paramString,tiddler) {
var parsedParams = paramString.parseParams("tag",null,true);
var refreshContainer = createTiddlyElement(place,"div");
// do some refresh magic to make it keep the list fresh - thanks Saq
refreshContainer.setAttribute("refresh","macro");
refreshContainer.setAttribute("macroName",macroName);
var tag = getParam(parsedParams,"tag");
var expr = getParam(parsedParams,"expr");
if (expr) {
refreshContainer.setAttribute("isTagExpr","true");
refreshContainer.setAttribute("title",expr);
refreshContainer.setAttribute("showEmpty","true");
}
else {
refreshContainer.setAttribute("isTagExpr","false");
if (tag) {
refreshContainer.setAttribute("title",tag);
refreshContainer.setAttribute("showEmpty","true");
}
else {
refreshContainer.setAttribute("title",tiddler.title);
refreshContainer.setAttribute("showEmpty","false");
}
}
this.refresh(refreshContainer);
},
refresh: function(place) {
var title = place.getAttribute("title");
var isTagExpr = place.getAttribute("isTagExpr") == "true";
var showEmpty = place.getAttribute("showEmpty") == "true";
removeChildren(place);
addClass(place,"tagglyTagging");
var countFound = config.taggly.getTiddlers(title,'title',isTagExpr).length
if (countFound > 0 || showEmpty) {
var lingo = config.taggly.lingo;
config.taggly.createListControl(place,title,"hideState");
if (config.taggly.getTagglyOpt(title,"hideState") == "show") {
createTiddlyElement(place,"span",null,"tagglyLabel",
isTagExpr ? lingo.labels.exprLabel.format([title]) : lingo.labels.label.format([title]));
config.taggly.createListControl(place,title,"title");
config.taggly.createListControl(place,title,"modified");
config.taggly.createListControl(place,title,"created");
config.taggly.createListControl(place,title,"listMode");
config.taggly.createListControl(place,title,"excerpts");
config.taggly.createListControl(place,title,"numCols");
config.taggly.createTagglyList(place,title,isTagExpr);
if (countFound == 0 && showEmpty)
createTiddlyElement(place,"div",null,"tagglyNoneFound",lingo.labels.noneFound);
}
}
}
}
},
// todo fix these up a bit
styles: [
"/*{{{*/",
"/* created by TagglyTaggingPlugin */",
".tagglyTagging { padding-top:0.5em; }",
".tagglyTagging li.listTitle { display:none; }",
".tagglyTagging ul {",
" margin-top:0px; padding-top:0.5em; padding-left:2em;",
" margin-bottom:0px; padding-bottom:0px;",
"}",
".tagglyTagging { vertical-align: top; margin:0px; padding:0px; }",
".tagglyTagging table { margin:0px; padding:0px; }",
".tagglyTagging .button { visibility:hidden; margin-left:3px; margin-right:3px; }",
".tagglyTagging .button, .tagglyTagging .hidebutton {",
" color:[[ColorPalette::TertiaryLight]]; font-size:90%;",
" border:0px; padding-left:0.3em;padding-right:0.3em;",
"}",
".tagglyTagging .button:hover, .hidebutton:hover, ",
".tagglyTagging .button:active, .hidebutton:active {",
" border:0px; background:[[ColorPalette::TertiaryPale]]; color:[[ColorPalette::TertiaryDark]];",
"}",
".selected .tagglyTagging .button { visibility:visible; }",
".tagglyTagging .hidebutton { color:[[ColorPalette::Background]]; }",
".selected .tagglyTagging .hidebutton { color:[[ColorPalette::TertiaryLight]] }",
".tagglyLabel { color:[[ColorPalette::TertiaryMid]]; font-size:90%; }",
".tagglyTagging ul {padding-top:0px; padding-bottom:0.5em; margin-left:1em; }",
".tagglyTagging ul ul {list-style-type:disc; margin-left:-1em;}",
".tagglyTagging ul ul li {margin-left:0.5em; }",
".editLabel { font-size:90%; padding-top:0.5em; }",
".tagglyTagging .commas { padding-left:1.8em; }",
"/* not technically tagglytagging but will put them here anyway */",
".tagglyTagged li.listTitle { display:none; }",
".tagglyTagged li { display: inline; font-size:90%; }",
".tagglyTagged ul { margin:0px; padding:0px; }",
".excerpt { color:[[ColorPalette::TertiaryDark]]; }",
".excerptIndent { margin-left:4em; }",
"div.tagglyTagging table,",
"div.tagglyTagging table tr,",
"td.tagglyTagging",
" {border-style:none!important; }",
".tagglyTagging .contents { border-bottom:2px solid [[ColorPalette::TertiaryPale]]; padding:0 1em 1em 0.5em;",
" margin-bottom:0.5em; }",
".tagglyTagging .indent1 { margin-left:3em; }",
".tagglyTagging .indent2 { margin-left:4em; }",
".tagglyTagging .indent3 { margin-left:5em; }",
".tagglyTagging .indent4 { margin-left:6em; }",
".tagglyTagging .indent5 { margin-left:7em; }",
".tagglyTagging .indent6 { margin-left:8em; }",
".tagglyTagging .indent7 { margin-left:9em; }",
".tagglyTagging .indent8 { margin-left:10em; }",
".tagglyTagging .indent9 { margin-left:11em; }",
".tagglyTagging .indent10 { margin-left:12em; }",
".tagglyNoneFound { margin-left:2em; color:[[ColorPalette::TertiaryMid]]; font-size:90%; font-style:italic; }",
"/*}}}*/",
""].join("\n"),
init: function() {
merge(config.macros,this.macros);
config.shadowTiddlers["TagglyTaggingStyles"] = this.styles;
store.addNotification("TagglyTaggingStyles",refreshStyles);
}
};
config.taggly.init();
//}}}
/***
InlineSlidersPlugin
By Saq Imtiaz
http://tw.lewcid.org/sandbox/#InlineSlidersPlugin
// syntax adjusted to not clash with NestedSlidersPlugin
// added + syntax to start open instead of closed
***/
//{{{
config.formatters.unshift( {
name: "inlinesliders",
// match: "\\+\\+\\+\\+|\\<slider",
match: "\\<slider",
// lookaheadRegExp: /(?:\+\+\+\+|<slider) (.*?)(?:>?)\n((?:.|\n)*?)\n(?:====|<\/slider>)/mg,
lookaheadRegExp: /(?:<slider)(\+?) (.*?)(?:>)\n((?:.|\n)*?)\n(?:<\/slider>)/mg,
handler: function(w) {
this.lookaheadRegExp.lastIndex = w.matchStart;
var lookaheadMatch = this.lookaheadRegExp.exec(w.source)
if(lookaheadMatch && lookaheadMatch.index == w.matchStart ) {
var btn = createTiddlyButton(w.output,lookaheadMatch[2] + " "+"\u00BB",lookaheadMatch[2],this.onClickSlider,"button sliderButton");
var panel = createTiddlyElement(w.output,"div",null,"sliderPanel");
panel.style.display = (lookaheadMatch[1] == '+' ? "block" : "none");
wikify(lookaheadMatch[3],panel);
w.nextMatch = lookaheadMatch.index + lookaheadMatch[0].length;
}
},
onClickSlider : function(e) {
if(!e) var e = window.event;
var n = this.nextSibling;
n.style.display = (n.style.display=="none") ? "block" : "none";
return false;
}
});
//}}}
/*{{{*/
/* created by TagglyTaggingPlugin */
.tagglyTagging { padding-top:0.5em; }
.tagglyTagging li.listTitle { display:none; }
.tagglyTagging ul {
margin-top:0px; padding-top:0.5em; padding-left:2em;
margin-bottom:0px; padding-bottom:0px;
}
.tagglyTagging { vertical-align: top; margin:0px; padding:0px; }
.tagglyTagging table { margin:0px; padding:0px; }
.tagglyTagging .button { visibility:hidden; margin-left:3px; margin-right:3px; }
.tagglyTagging .button, .tagglyTagging .hidebutton {
color:[[ColorPalette::TertiaryLight]]; font-size:90%;
border:0px; padding-left:0.3em;padding-right:0.3em;
}
.tagglyTagging .button:hover, .hidebutton:hover,
.tagglyTagging .button:active, .hidebutton:active {
border:0px; background:[[ColorPalette::TertiaryPale]]; color:[[ColorPalette::TertiaryDark]];
}
.selected .tagglyTagging .button { visibility:visible; }
.tagglyTagging .hidebutton { color:[[ColorPalette::Background]]; }
.selected .tagglyTagging .hidebutton { color:[[ColorPalette::TertiaryLight]] }
.tagglyLabel { color:[[ColorPalette::TertiaryMid]]; font-size:90%; }
.tagglyTagging ul {padding-top:0px; padding-bottom:0.5em; margin-left:1em; }
.tagglyTagging ul ul {list-style-type:disc; margin-left:-1em;}
.tagglyTagging ul ul li {margin-left:0.5em; }
.editLabel { font-size:90%; padding-top:0.5em; }
.tagglyTagging .commas { padding-left:1.8em; }
/* not technically tagglytagging but will put them here anyway */
.tagglyTagged li.listTitle { display:none; }
.tagglyTagged li { display: inline; font-size:90%; }
.tagglyTagged ul { margin:0px; padding:0px; }
.excerpt { color:[[ColorPalette::TertiaryDark]]; }
.excerptIndent { margin-left:4em; }
div.tagglyTagging table,
div.tagglyTagging table tr,
td.tagglyTagging
{border-style:none!important; }
.tagglyTagging .contents { border-bottom:2px solid [[ColorPalette::TertiaryPale]]; padding:0 1em 1em 0.5em;
margin-bottom:0.5em; }
.tagglyTagging .indent1 { margin-left:3em; }
.tagglyTagging .indent2 { margin-left:4em; }
.tagglyTagging .indent3 { margin-left:5em; }
.tagglyTagging .indent4 { margin-left:6em; }
.tagglyTagging .indent5 { margin-left:7em; }
.tagglyTagging .indent6 { margin-left:8em; }
.tagglyTagging .indent7 { margin-left:9em; }
.tagglyTagging .indent8 { margin-left:10em; }
.tagglyTagging .indent9 { margin-left:11em; }
.tagglyTagging .indent10 { margin-left:12em; }
.tagglyNoneFound { margin-left:2em; color:[[ColorPalette::TertiaryMid]]; font-size:90%; font-style:italic; }
/*}}}*/
! The vi editor
!! vi Intro
!!! Background:
* ex, vi, vim
** {{Command{ex}}} = line oriented text editor (for printed output / slow displays / modems)
*** demonstrate ''c'' (change) and ''i'' (insert) commands. Go to a line number, use command with ''.'' to return to prompt.
** {{Command{vi}}} = screen oriented instead of line oriented
*** Different modes - either entering text or executing commands
*** Commands are either {{Command{vi}}} commands or {{Command{ex}}} commands.
** {{Command{ex}}} & {{Command{vi}}} are different interfaces to the same program
** {{Command{ex}}} & {{Command{vi}}} began with original unix versions, over 30 years ago
** {{Command{vi}}} is now the standard unix text editor
** {{Command{vim}}} = vi Improved - extra commands and functionality
!!! Using vi:
* Opening a document for editing loads it into a buffer, which is the in-memory text of a file.
** Any changes are made to the buffer and not saved to the file until the //write// command is provided.
* There are two Modes:
** Command mode - where you provide commands to the editor
*** These may be either {{Command{vi}}} or {{Command{ex}}} commands
** Input mode - where you can interact with the content of the file
*** You'll typically see the string ''-- INSERT --'' in the bottom-left corner when you're in Input Mode
*** Leave input mode by pressing ESC
* vi commands (command mode) contain an operator (what to do) and scope (what to do it on)
** Examples:
*** {{Monospaced{''d$''}}} - delete (d) all text from the cursor to the end of the line ($ typically means end of line)
*** {{Monospaced{''dw''}}} - delete (d) the current word
*** {{Monospaced{''d5w''}}} - delete (d) the current and next 4 (5) words (w)
*** {{Monospaced{''d2d''}}} - delete (d) the current and next 1 (2) line (d)
*** {{Monospaced{''cw''}}} - change (c) the next word (w), placing you in input mode
*** {{Monospaced{''ct:''}}} - change (c) all characters until (t) the next colon (:)
* Searching with ''/'' and ''?''
** Search down with the ''/'' key
** Search up with the ''?'' key
*** After you type either ''/'' and ''?'', you cursor will move to the bottom-left corner and you will be prompted to enter a search string. Press enter to begin the search.
** Repeat your last search with ''n''
!! Using ex commands in vi
The {{Command{vi}}} editor is a the ''vi''sual screen-oriented front-end for the {{Command{ex}}} line-oriented text editor. {{Command{ex}}} was one of the original Unix text editors from the days where text files could only be displayed and edited one line at a time. It wasn't yet possible to display a full screen of text. The ''vi''sual functionality was supported after technology evolved to support full-screen document editing. {{Command{vi}}} also supports the original {{Command{ex}}} commands for manipulating a document. These commands bring a great deal of power to the editor and make solving complex tasks rather simple.
* Press the : (colon) key to enter {{Command{ex}}} command mode when you are no in Input mode. Your cursor will move to the bottom left corner.
* {{Command{ex}}} commands will be displayed on the bottom status line. Press ~CTRL-C to cancel the command and return to vi mode.
* Syntax: {{Monospaced{'' :[address]command ''}}}
** {{Monospaced{'' :[address] ''}}} is an optional component which allows you to specify which lines to act upon.
!!! Valid address formats
* Addresses may be addressed singly:
** {{Monospaced{''.''}}} - represents current line (default if no address is specified)
** {{Monospaced{''//n//''}}} - a specific line number
** {{Monospaced{''$''}}} - last line in the file
* or as a range:
**{{Monospaced{''%''}}} - Whole file
** {{Monospaced{''address1,address2''}}} - from address1 to address2.
** Also includes +//n// and -//n// to include the next or previous //n// lines
* Examples:
** {{Monospaced{'':12,20d''}}} - delete lines 12 to 20
** {{Monospaced{'':.,+5''}}} - current and next five lines
** {{Monospaced{'':10,$''}}} - lines 10 through the end of the file
** {{Monospaced{'':$-2,$''}}} - last three lines (last line and two previous)
!!! Most useful ex commands
* ''d'' - delete lines
** {{Monospaced{'':10d''}}} - delete line 10
** {{Monospaced{'' :1,10d ''}}} - delete lines 1 to 10
* ''e'' - edit
** {{Monospaced{'':e! ''}}} - reopen current file, discarding changes
* ''s'' - substitute
**{{Monospaced{'' :s/one/two/ ''}}} - change first instances of one to two on the current line
**{{Monospaced{'' :%s/one/two/ ''}}} - change first instance of one to two on all lines in the document
**{{Monospaced{'' :%s/one/two/g ''}}} - change all instances of one to two on all lines in the document
**{{Monospaced{'' :.,+5s/one/two/g ''}}} - change all instances of one to two on current and next 5 lines.
* ''g'' - globally execute specified commands on lines containing a particular pattern
** {{Monospaced{'' :g/stuff/d ''}}} - delete all lines containing the string stuff
** {{Monospaced{'' :g/lpd-errs/s/^/#/ ''}}} - add a comment to the beginning of the line on all lines containing the string lpd-errors
** {{Monospaced{'' :10,20/g/stuff/d ''}}} - remove lines between lines 10 and 20 that contain the string delete
----
!! More info
*vi handouts: [[vi Diagram|handouts/viDiagram.pdf]] & [[Old Handout|handouts/viHandout.pdf]]
*{{Command{vimtutor}}} command
*http://www.gentoo.org/doc/en/vi-guide.xml
*[[UNIX Command summary|handouts/UnixCommandSummary.pdf]] back page
http://docstore.mik.ua/orelly/unix/unixnut/ch09_01.htm
! Using the compilers
Also a simple exercise to get more practice editing text files with vi
{{Command{gcc}}} & {{Command{g++}}}
Use {{Command{gcc}}} for compiling C code and {{Command{g++}}} for compiling C++ code. Source code file extensions must either be .c or .cpp
{{Command{gcc -o //name_of_executable// source.c}}}
{{Command{g++ -o //name_of_executable// source.cpp}}}
//name_of_executable// = executable file to create after compiling your source code, instead of using the default a.out
{{{
#include <stdio.h>
main()
{
printf("Hello World in C\n\n");
}
}}}
{{{
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World!" << endl;
return 0;
}
}}}
! Assignments
!! Read :
- Chapter 12 in [[The Linux Command Line|http://www.merantn.net/reference/TLCL-19.01.pdf]]
!! Complete:
- [[Lab 27|labs/lab27.pdf]] & [[Lab 28|labs/lab28.pdf]]
- These labs are optional for additional vi practice and will be accepted for extra credit.
/***
|Name|ToggleSideBarMacro|
|Created by|SaqImtiaz|
|Location|http://lewcid.googlepages.com/lewcid.html#ToggleSideBarMacro|
|Version|1.0|
|Requires|~TW2.x|
!Description:
Provides a button for toggling visibility of the SideBar. You can choose whether the SideBar should initially be hidden or displayed.
!Demo
<<toggleSideBar "Toggle Sidebar">>
!Usage:
{{{<<toggleSideBar>>}}} <<toggleSideBar>>
additional options:
{{{<<toggleSideBar label tooltip show/hide>>}}} where:
label = custom label for the button,
tooltip = custom tooltip for the button,
show/hide = use one or the other, determines whether the sidebar is shown at first or not.
(default is to show the sidebar)
You can add it to your tiddler toolbar, your MainMenu, or where you like really.
If you are using a horizontal MainMenu and want the button to be right aligned, put the following in your StyleSheet:
{{{ .HideSideBarButton {float:right;} }}}
!History
*23-07-06: version 1.0: completely rewritten, now works with custom stylesheets too, and easier to customize start behaviour.
*20-07-06: version 0.11
*27-04-06: version 0.1: working.
!Code
***/
//{{{
config.macros.toggleSideBar={};
config.macros.toggleSideBar.settings={
styleHide : "#sidebar { display: none;}\n"+"#contentWrapper #displayArea { margin-right: 1em;}\n"+"",
styleShow : " ",
arrow1: "«",
arrow2: "»"
};
config.macros.toggleSideBar.handler=function (place,macroName,params,wikifier,paramString,tiddler)
{
var tooltip= params[1]||'toggle sidebar';
var mode = (params[2] && params[2]=="hide")? "hide":"show";
var arrow = (mode == "hide")? this.settings.arrow1:this.settings.arrow2;
var label= (params[0]&¶ms[0]!='.')?params[0]+" "+arrow:arrow;
var theBtn = createTiddlyButton(place,label,tooltip,this.onToggleSideBar,"button HideSideBarButton");
if (mode == "hide")
{
(document.getElementById("sidebar")).setAttribute("toggle","hide");
setStylesheet(this.settings.styleHide,"ToggleSideBarStyles");
}
};
config.macros.toggleSideBar.onToggleSideBar = function(){
var sidebar = document.getElementById("sidebar");
var settings = config.macros.toggleSideBar.settings;
if (sidebar.getAttribute("toggle")=='hide')
{
setStylesheet(settings.styleShow,"ToggleSideBarStyles");
sidebar.setAttribute("toggle","show");
this.firstChild.data= (this.firstChild.data).replace(settings.arrow1,settings.arrow2);
}
else
{
setStylesheet(settings.styleHide,"ToggleSideBarStyles");
sidebar.setAttribute("toggle","hide");
this.firstChild.data= (this.firstChild.data).replace(settings.arrow2,settings.arrow1);
}
return false;
}
setStylesheet(".HideSideBarButton .button {font-weight:bold; padding: 0 5px;}\n","ToggleSideBarButtonStyles");
//}}}
|~ViewToolbar|closeTiddler closeOthers editTiddler > fields syncing permalink references jump|
|~EditToolbar|+saveTiddler -cancelTiddler deleteTiddler|
{{Note{This video is a nice demo and overview on how this all works. It may be helpful to review it before proceeding. https://www.youtube.com/watch?v=XFJ6_BYno08}}}
!! Defeating firewalls with SSH to access protected resources
Knowing how to more fully use SSH and it's tunneling and proxy capabilities to defeat firewalls or access private IP addresses over the internet is an excellent skill for a security practitioner to have! There are two methods we can use with SSH to defeat firewalls and access these resources:
A. Dynamic application-level port forwarding (SOCKS proxy)
<<<
Specifies local "dynamic" application-level port forwarding. This works by allocating a socket to listen to a port on the local side, optionally bound to the specified bind_address. Whenever a connection is made to this port, the connection is forwarded over the secure channel, and the application protocol is then used to determine where to connect to from the remote machine.
<<<
B. Port forwarding
<<<
Specifies that connections to the given TCP port or Unix socket on the local (client) host are to be forwarded to the given host and port, or Unix socket, on the remote side. This works by allocating a socket to listen to either a TCP port on the local side, optionally bound to the specified bind_address, or to a Unix socket. Whenever a connection is made to the local port or socket, the connection is forwarded over the secure channel, and a connection is made to either host port hostport, or the Unix socket remote_socket, from the remote machine.
<<<
Method A. functions as a traditional application-level proxy. You would configure your application (eg: web browser) to proxy all connections through the tunnel. Method B. creates a 1:1 connection: a TCP port on your local PC is tunneled through the SSH connection to a specific IP address and TCP port on the other side. This method is best when there is no option to configure a proxy in your application.
We're going to use method ''A'' for accessing internal web resources behind our class router. This grants us the most flexibility since our browser allows us to configure an application-level proxy.
Before you begin, open your web browser and load the page http://ifconfig.me. Take note of the IP address displayed. We will compare this to the IP address you receive after everything is set up.
!!! A. Establishing a SOCKS proxy with SSH
A proxy is a middle man, passing on network requests to their destination on your behalf.
A SOCKS proxy (socket secure) is a protocol to route packets between a client and a server through an intermediate proxy. This is used (typically for web traffic) when the client is not able to communicate with the server directly, but the client can communicate with the proxy system and the chosen proxy can communicate with the server. Some sites set up a proxy for web traffic as a means to enforce policy, monitor traffic, and block direct connections to web sites.
Here, your home PC cannot access your web server VM or the Naemon monitoring server but the class shell server can. We'll use the class shell server to proxy your browser's web connections and be the middleman for your web requests. This diagram illustrates the overall goal. We see your proxy connection traveling through the encrypted SSH tunnel to the class shell server. Web requests are then made from the perspective of the class shell server.
[img[img/proxy.png]]
SSH can be used to establish a SOCKS proxy. This functionality is available from putty or the command line ~OpenSSH
''1.'' To set up the Proxy on your home PC, complete either ''a)'' or ''b)'', depending on your OS:
''a)'' If your home OS is Mac or Unix: This command will create an encrypted proxy tunnel between your PC and the specified host, in this case our class shell server. Traffic connecting to your PC on port 8118 will then pass through this proxy. Execute a similar command on your home computer. You may also need to update the username.
<<<
Set up SOCKS proxy: {{Command{ssh -p 2307 -D 8118 lab.cs307.net}}}
<<<
''b)'' Follow these steps when connecting with Putty from your home Windows PC:
<<<
* Expand the Connection / SSH menu
* Select Tunnels
* Enter ''8118'' in the Source port box
* Select ''Dynamic''
* Click Add
* Connect to a remote host (the class shell server) as normal
<<<
* [[This video|Putty Proxy]] demonstrates configuring Putty to add the dynamic tunnel.
''2.'' Your browser must be configured to pass traffic through the encrypted proxy.
I use the ~FoxyProxy extension to easily toggle between proxy settings in my browser. It can also be configured to automatically send only selected sites through the proxy.
* Firefox:
** [[Firefox Extension|https://addons.mozilla.org/en-US/firefox/addon/foxyproxy-standard/]]
** ~CS307 settings file for use in Firefox: [[FoxyProxy-cs307.json|https://www.cs307.net/media/FoxyProxy-cs307.json]]
* Chrome:
** [[Chrome Extension|https://chrome.google.com/webstore/detail/foxyproxy-standard/gcknhkkoolaabfmlnjonogaaifnjlfnp]]
** I don't have a version of the config for Chrome; you're on your own for now and will need to configure it manually.
** Be sure to check the //Proxy DNS// option
Install the browser extension, import the settings file, and enable the proxy.
* [[This video|Firefox Proxy]] demonstrates using Firefox with the proxy to access an internal website
!!! B. Verification
Verification should be built into everything you configure. Now that your proxy is established, let's verify it is functioning correctly and web connections from Firefox are flowing through the class infrastructure. Load the page http://ifconfig.me again in your browser and observe the IP address. It should have changed from the original value you observed and instead contain the public IP address of the class shell server. Next, run the command {{Command{curl ifconfig.me}}} on the class shell server. The IP address in your browser and displayed on the command line should match. This will confirm your traffic is now properly going through the proxy.
With the class server acting as a middle man, you can now load internal resources in this web browser which would have otherwise been blocked from the outside world.
!!! C. Naemon infrastructure monitoring
[[Naemon|https://www.naemon.org/]] is a tool which continuously monitors resources to provide a high level view of the health of an environment. I'm running a Naemon server to monitor your ~VMs and use it to assist with grading your labs. You can also use it to monitor the state of your systems and correct any issues it discovers.
Naemon is running on the internal class network and is not directly accessible from the outside world. You will need to bypass the router and use the class shell server as a proxy in order to reach it.
Once the proxy is configured in your browser, navigate to the URL '' http://head.cs307.net/ ''. The username is ''cs307'' and password is ''naemon''.
This video contains a brief [[Naemon Introduction]].
{{Note{Naemon status checks run every two hours. If you fix a problem, you will either need to wait up to two hours for the recheck or force Naemon to recheck.}}}
{{Warning{Warning: Naemon checks are not a replacement for your own sound testing and verification. They may return false positives and negatives. Not every possibility can be evaluated. They are only a troubleshooting and status aid; not a definitive determination that something is correct. I will still perform manual testing for most of your labs that Naemon cannot fully evaluate.}}}
!! Asking for help
* Title your posts appropriately. Use something descriptive in the name and not just the lab and question number. A subject like @@Lab 17, #2 - Incorrectly discarding data@@ is far more helpful than something generic like ''Lab 17''.
* When asking for help in blackboard, be sure to include relevant supporting information. You'll receive faster responses if you provide everything someone needs to help you.
** If you're asking about a lab question, include that question in your post so everyone doesn't need to first look at the lab.
** Did you receive an error from a command? Be sure to include the error and the command you ran. The shell prompt will also include helpful information:
*** The host you're running the command on
*** The user you're running the command as
*** A portion of the current working directory. Including the full output of the {{Command{pwd}}} command would be helpful too
*** The exact command string you're running.
** Don't forget to include any relevent log information and troubleshooting steps you've already taken. You're more likely to get help if you start the process and can describe what you've already done to troubleshoot.
* Be sure to review everything for typos first. Too many posts to Blackboard asking for help will be for problems caused by typos. Save some time and check your typing first.
* Screenshots are helpful too. Pictures are worth a thousand words.
!! Posting Screenshots
When posting screenshots, use the Insert Local Files(circled) in Blackboard. Don't attach a file. It's much easier work with embedded images than ones that need to be opened in a new tab.
@@display:block;text-align:center;[img[img/screenshots.png]]@@
!! Pasting in terminal output
Everyone should be using the Blackboard discussion boards during the course of the semester and will likely need to paste in output from the command line at some point.
Aesthetics and readability should be considered in everything you produce. We can make our post easier to read with a couple additional steps.
''1.'' Paste your copied text from the terminal where you would like it to appear. Finish typing out your message. Before sending, change the formatting for the portions you pasted from the terminal.
''2.'' Select the text you pasted in and change the paragraph type to Formatted Code. This will remove the double spacing.
''3.'' Select the text you pasted in and choose the font ''Courier New''. All commands and text copied from the terminal should be written with a monospaced font like Courier New to make spacing uniform between the characters and show that what you're typing is a command or output from one.
''4.'' Select the command you executed to get the output and change it to bold. This makes it easier to identify the command that was used from the output returned. Including the shell prompt and executed command provides important context.
''5.'' If appropriate, use the highlighter to draw attention to any parts you're talking about. Be sure to first change the color to a brighter one.
@@display:block;text-align:center;[img[img/blackboard4.png]]@@
You'll finally be left with something that is much easier to read. You're more likely to get a response to your forum post if you provide all necessary information in a way that's easy to work with. Pasting text like this is preferable to just posting a screenshot. If you paste in the text, someone can quote it in a reply and easily highlight relevant parts.
@@display:block;text-align:center;[img[img/blackboard3.png]]@@
/%
----
avoid Blackboard's text mangling and
If you paste copied text from the terminal, blackboard will turn it into a mangled mess:
than the Blackboard mangled mess
@@display:block;text-align:center;[img[img/blackboard0.png]]@@
''1.'' Insert a few blank lines where you want to put the pasted text. These blank lines will make it easier to add additional text after inserting your pasted text from the terminal
''2.'' Choose the HTML editor from the Toolbar
@@display:block;text-align:center;[img[img/blackboard1.png]]@@
''4.'' Add a {{Command{<pre>}}} HTML tag before your pasted text and a {{Command{</pre>}}} tag after it. This will prevent the mangled formatting and preserve all spacing, just as you see it in the terminal.
@@display:block;text-align:center;[img[img/blackboard2.png]]@@
''5.'' Click update. You should now see your copied text nicely formatted in Blackboard.
''6.'' Select the text you pasted in and choose the font ''Courier New''. All commands and text copied from the terminal should be written with a monospaced font like Courier New to make spacing uniform and highlight what you're typing is a command or output from one.
''7.'' Highlight the command you executed to get the output and change it to bold. This makes it easier to identify the command that was used from the output returned.
''8.'' If appropriate, use the highlighter to draw attention to any parts you're talking about. Be sure to first change the color to a brighter one.
@@display:block;text-align:center;[img[img/blackboard4.png]]@@
You'll finally be left with something that is much easier to read than the Blackboard mangled mess. You're more likely to get a response to your forum post if it is easier to read. Pasting text like this is preferable to just posting a screenshot. If you paste in the text, someone can quote it in a reply and easily highlight relevant parts.
@@display:block;text-align:center;[img[img/blackboard3.png]]@@ %/
!! Organization
We'll need to keep Discord organized in order to keep it useful. Get in the habit of this now, because you'll have these same issues later in the workplace. The concepts are very similar to what we need to do on Slack in the corporate world.
!!! There are four types of channels:
# //administrative// - Administrative questions about the class like grading, due dates, and general technical support issues. Not for course content.
# //misc-chatter// - Conversation not related to this class
# //resources// - Posts about general course notes and resources that might be helpful for others
# //week#// - The weekly course content discussions. These are Forum channels. Create a new post in this channel regarding material that was ''//assigned//'' in this week.
** For example, if you have a question about a week 1 lab, create a post in the week 1 channel even if we're now in week 2.
** Only posts in these weekly channels will be evaluated for a grade
!! Asking for help
* ''Required reading'': https://www.nohello.com/
** This is such an issue in corporate communication that there's a website dedicated to it. Discord for this class should be treated as business comms.
** Don't waste time with just an empty //hello// without asking your question. It could cause hours or even days to be wasted.
* Use threads for your questions to help keep things organized.
** See below for an example on using threads
** Title your threads appropriately. Use something descriptive in the name and not just the lab and question number. A subject like @@Lab 17, #2 - Incorrectly discarding data@@ is far more helpful than something generic like ''Lab 17''.
** Organization and usability is important in everything you do. Get good at this now.
* When asking for help, be sure to include relevant supporting information. You'll receive faster responses if you provide everything someone needs to help you.
** If you're asking about a lab question, including that question in your post is helpful so everyone doesn't need to first look at the lab to know what you're talking about.
** Send us what you're seeing, don't just describe it. A picture is worth a thousand words. Screenshots often capture additional detail omitted from a text description.
*** Did you receive an error from a command? Be sure to include the error and the command you ran.
*** The shell prompt will also include helpful information, such as:
**** The host you're running the command on
**** The user you're running the command as
**** A portion of the current working directory. Including the full output of the {{Command{pwd}}} command might be helpful too
**** The exact command string you're running.
** Don't forget to include any relevant log information, configuration lines, and troubleshooting steps you've already taken. You're more likely to get help if you start the process and can describe what you've already done to troubleshoot.
* Be sure to review everything for typos first. Too many posts asking for help will be for problems caused by typos. Save some time and check your typing first.
* If you solve your problem while you're waiting for help, be sure to post an update. Don't let someone else waste their time helping you when you no longer need it.
!! Using code blocks
* Be sure all code, commands, and output is enclosed within a code block. This will make it easier to identify commands and prevent Discord from interpreting special characters.
* Single commands can be put inside of a code block by enclosing your command in ''backticks''.
* A series of lines can be put inside of a code block by putting ''three backticks'' at the start of the first line and three backticks at the end of the last line.
* When possible, sending text in code blocks is better then just sending a screenshot. Text sent in a screenshot cannot be copy/pasted for any testing
* A full list of Markdown formatting options is available in the [[Discord help docs|https://support.discord.com/hc/en-us/articles/210298617-Markdown-Text-101-Chat-Formatting-Bold-Italic-Underline-]]
Example of using single line code block:
[img[img/discord-code3.png]]
Example of using multi-line code block:
[img[img/discord-code1.png]]
Results of using code blocks:
[img[img/discord-code2.png]]
!! Using forum posts
Our weekly content channels are forum channels. Each question or discussion topic will be a new forum post.
----
[img[img/discord1.png]]
# Click on the week number for the material you would like to discuss
# Click on the //New Post// button
----
[img[img/discord2.png]]
# Enter an appropriate title for your post
# Enter your question as the opening message followed by any supporting information.
# Click on //Post//
----
[img[img/discord3.png]]
# If you would like to follow an interesting post, right-click on the message and select //Follow Post//.
----
[img[img/discord4.png]]
* Your followed posts will appear under the weekly channel. This will make the post easier to find later and join the conversation.
<!--{{{-->
<div class='toolbar' macro='toolbar [[ToolbarCommands::ViewToolbar]]'></div>
<div class='title' macro='view title'><span class="miniTag" macro="miniTag"></span></div>
<div class='subtitle'>Updated <span macro='view modified date [[MMM DD, YYYY]]'></span> (<span macro='message views.wikified.createdPrompt'></span> <span macro='view created date [[MMM DD, YYYY]]'></span>)<BR><BR></div>
<div class='viewer' macro='view text wikified'></div>
<div class="tagglyTagging" macro="tagglyTagging"><BR><BR></div>
<div class="tagglyTagged" macro="hideSomeTags"></div>
<div class='tagClear'></div>
<!--}}}-->
! Introduction to CS 307
!!! Expectations:
Mostly outlined in the [[syllabus|syllabus/CS307Syllabus2501.pdf]], but to recap:
* ''Honesty & Integrity'' - Cheating generally results in a failing ''course'' grade.
** This course is in a security program. If you cannot be trusted, you do not belong here.
* ''Motivation & practice'' - You must be motivated to practice the work in order to pick up the material.
** Here's a good article discussing [[productive struggle|http://maateachingtidbits.blogspot.com/2017/11/the-role-of-failure-and-struggle-in.html]] that roughly outlines how I'm teaching this course.
* ''Graded Homework'' - Almost everything will be graded.
* ''Don't fall behind'' - Else the workload will bury you.
** Please let me know early if you're starting to run into trouble.
This class will also use Linux as a vehicle for reinforcing good soft skills. You will be expected to:
* Provide clear and thorough explanations
* Ask questions when help is needed
* Be an active participant in your learning
** Using a whitewater rafting analogy - I'll be the guide and you're our paddlers. I'll chart the path, but you need to get us there.
!!! Class Resources
* Required Textbooks:
** [[Harley Hahn's Guide to Unix and Linux|https://www.harley.com/unix-book/book/chapters/home.html]] (free online or available in print)
* Optional Textbook:
** Second half of the semester - [[Linux Command Line and Shell Scripting Bible, Fourth Edition|https://onlinelibrary.wiley.com/doi/book/10.1002/9781119209409]]
* Class website: https://www.cs307.net/
** The class website will be our primary resource for course content
** Each content page is generally divided into three sections:
### the content assignment (what to read or watch),
### my notes about the content
### the deliverables for that content
** The search function on the class website is your friend. Click the << in the top-right corner to open the side menu bar.
* Brightspace
** [[Brightspace|https://mylearning.suny.edu/d2l/login]] will be used only for announcements and initial class kickoff information.
* Discord will be used for regular class communication
** An invite to our server has been posted to Brightspace
** Discord participation will be [[evaluated as well|Class Participation]].
* Grades
** Grades will be tracked in a text file within your home directory on the class shell server: {{File{.grades.txt}}}
** Be sure to note the dot at the start of the file name
** A command like {{Command{cat ~/.grades.txt}}} will display your grades.
!!! Class Cadence
* A week's worth of new material will be posted to the class website Sunday evening in two parts.
** Unless stated otherwise, part 1 assignments will be due by end of day Wednesday
** Part 2 assignments will be due by end of day Saturday.
** An [[assignment calendar|Calendar]] can be found on our class website in the menu bar above.
* Carnegie credit hour
** A Carnegie credit hour is defined as 50 minutes of lecture and 2 hours of prep/homework for each traditional course credit hour
** This requirement is defined in [[SUNY Policy|https://www.suny.edu/sunypp/documents.cfm?doc_id=168]]
** Translated to our hybrid class, this means we are expected to perform approximately 11 hours of instructional activity per week
** This is hard to gauge for online classes when we don't meet. Please let me know if you feel we are regularly exceeding that.
!!! Extra Help
Several options exist if you are stuck and would like some extra help.
* Post your question or problem to the class Discord server
** Be sure to post to the channel for the week the material was assigned
* Ad-hoc online meetings via Zoom. Let me know if you'd like to schedule one.
* Regularly scheduled weekly Zoom meetings. We can offer these if there is interest.
* Weekly office hours. We can schedule these once the semester gets settled in.
{{Warning{
This class will test your skills as a student; ''being a good student will be important in order to successfully complete this course''. This will not be one where you can do the bare minimum and skate by with a good grade. Good ''time management'' and ''study skills'' will be critical. ''If you neglect the material you will likely not successfully complete the course.''
Everything we do this semester will look back on previous work. If you're rushing through and not retaining it, you will surely pay for it later. Having a keen eye for detail, paying attention to the directions, and taking the time to practice and retain the material will make for a much smoother semester.
}}}
!! Accessing the class shell server
The class shell server is an always-on system we will connect to in order to practice the class assignments and submit homework. There are two ways we will access the system - from the command line for entering commands or through a file transfer utility for uploading files.
!!! Connection Tools
* Access the shell (command line) with either:
** [[PuTTY for Windows|http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html]] (Download the latest version of the 64-bit MSI installer)
** [[PuTTY for Mac|https://www.ssh.com/ssh/putty/mac/]]
** Mac, Linux, or Windows Subsystem for Linux: You can also use the command-line SSH. Launch your terminal and run the command {{Command{ssh -p 2307 //username//@lab.cs307.net}}}.
* Transfer files between the server and your local system:
** Windows: [[WinSCP|https://winscp.net/eng/download.php]]
** Mac: scp/sftp on the command line or any SFTP client like [[FileZilla|https://filezilla-project.org/]]
* Portable versions exist for these applications. This is convenient if you are using campus ~PCs that do not have the tools installed. You may download and run them from a flash drive or your home directory in the lab.
** [[PuTTY|http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html]] - Download and run putty.exe
** [[WinSCP|https://winscp.net/eng/download.php]]: Download the portable package
!!! Logging in
* Use one of the tools above to log in to ''lab.cs307.net'' on port ''2307''
* Log in with your campus username
* Your initial password will be posted to the main //Content// page in Brightspace.
* Change your password after logging in.
** Run the {{Command{passwd}}} command to change your password
** ''Any accounts still using the default password will be locked on Saturday, September 7.''
This short video will walk you through downloading ~PuTTY, a unix remote access client, and connecting to the system for command line access. Be sure to change the connection details to match the information above.
Video: [[Accessing the shell server]]
/% Download: ~PuTTY - [[installer|https://the.earth.li/~sgtatham/putty/latest/w64/putty-64bit-0.70-installer.msi]] or [[exe|http://the.earth.li/~sgtatham/putty/latest/win64/putty.exe]] %/
!! Working on the command line
Console
* Console is considered the interface with a system as though you are physically sitting at its monitor and keyboard. This lets us interact with the system before the operating system loads
* A virtual console is available for ~VMs or through a lights-out management utility such as a Dell iDRAC.
Remote access
* Remote access to a Linux system such as our class shell server can also be obtained through a remote access service like SSH (Secure ~SHell).
* SSH is the standard command-line remote access interface for Unix/Linux systems. It allows us to interact via a SSH client, much like how your web browser is a client to a web server.
* Our class shell server is a traditional timeshare server. It's always available; we don't power it off.
Shells
* The shell is our interface with the command line. It's a program that takes input from the user, passes it on to the system to process, and returns any output back to you.
!!! Navigating our lab server's filesystem:
* Directory paths
** Directory paths enable us to have a hierarchy of directories and keep our files organized
** Similar to the command line on Windows
** The path separator is a forward slash on Unix/Linux systems - {{File{''/''}}}
** Change directories with the {{Command{cd}}} command
*** eg: {{Command{cd /opt/pub/cs307/submit}}}
** List the contents of the directory with the {{Command{ls}}} command
** List the contents of the directory in long format with the {{Command{ls -l}}} command
*** Displaying the contents of a directory in long format is always preferred so you can easily see all information about the files
* Some directories of interest:
** {{File{/home/}}} - User home directories **typically** reside below this directory tree. This is just a standard convention - home directories can be anywhere on the system.
*** A user home directory is a space where each user can save their files.
** {{File{/opt/pub/cs307/submit/}}} - Lab/Homework assignments are uploaded to this directory
** {{File{/opt/pub/cs307/returned/}}} - Graded homework assignments are stored in this directory for you to download
** {{File{/opt/pub/cs307/data/}}} - Data files for labs are stored here
** {{File{/tmp/}}} - Temporary scratch space
!!! Executing commands
* Structure of a command string:
** {{Command{''command'' [options] [arguments]}}}
** options and arguments may be optional or required depending on the command
** In Unix command documentation, an item within the square brackets is an optional component. Some commands will also require arguments and some will not.
*** The documentation for each command will outline its requirements.
* Viewing files
** Display a file: {{Command{cat //filename//}}}
** Display a file one page at a time: {{Command{less //filename//}}}
** Edit a text file: {{Command{nano //filename//}}} ''-or-'' {{Command{vi //filename//}}}
!!! Other useful commands
* The UNIX manual - {{Command{man}}}
** If you want to learn more about a command, check out its manpage.
** For example, {{Command{man ls}}} will display detail about the {{Command{ls}}} command
!!! Using Discord
* Class discussion in Discord will make up 10% of your total course grade this semester.
* How this part is graded is discussed in the [[Class Participation]] page
* [[Using Discord]] contains some tips for how to post
!!! Working efficiently
* View your previously executed commands with the {{Command{history}}} command
* Tab completion - Press the tab key to autocomplete commands or file paths
* Up / Down arrows - search up and down through your command history
* Page Up / Page Down - Use these keys to search through your command history for the last commands which begin with a given string
** For example, typing {{Command{ls}}} and then pressing Page Up will jump you to the last command string you executed which started with {{Command{ls}}}.
* The [[Linux Shortcuts]] page will have some more useful items.
!! Submitting homework assignments
See the [[Lab Assignments]] page for details
! Material
!! Read:
* Chapters 1 & 2 in //Harley Hahn's Guide to Unix and Linux//
! Operating system basics
!! The core components of a Unix/Linux operating system are:
* Kernel - The main control program of the computer with handles process control, resource management, and interfaces with the hardware.
* File system - Organizes location of items on the system. Everything is shown as a file in the Unix asdas world.
* Shell - The primary interaction between the user and the system on the command line. The shell receives and interprets commands entered by users and passes them on to the kernel to execute.
!! Secondary components:
These are not part of the core OS, but necessary to do useful things with the system
* Basic Utilities - Many are from the GNU project
** System - Tools an administrator would use: mount, dd, fsck
** Userland - Tools regular users would use: file system tools (cd, ls, mkdir), text editors (vi, pico), filters (grep, cut, sed), process tools (ps, kill)
* Development environment - compilers and script interpreters
* System Documentation - man pages, info docs, etc.
* Window Managers - Desktop editions typically add a graphical environment, such as Gnome, KDE, or XFCE
* Larger Applications - Word processor, image editor, web browsers, etc
* Specialized utilities - (For example, tools that come with a focused distro like Kali)
!! UNIX is an OS that supports:
* Multi-tasking - foreground and background processes
* ~Multi-User - Multiple users may access the system at the same time
** Privilege separation - There are system administrators (root user) and regular users. Regular users are able to be isolated from each other
* Time sharing - Share computing resources among many users
* Portability - Can be run on different types of hardware systems/architectures (~PCs, servers, game systems, phones, embedded systems, etc)
!! Types and history of Unix/Linux
* This all started at Bell Labs as a research project
** 1969 Bell labs - AT&T Unics (Uniplexed Information & Computing Service)
** Unics became UNIX when multiuser support was added
** As part of a 1958 antitrust agreement with the government, AT&T could not go into the computer business and charge for software. They had to give free licenses to anyone who asked.
** Source code distributed to researchers at universities allowing them to modify and extend the OS
** Early Unix editions were numbered 1 - 10 based on the edition of the printed manual. It was still mostly for research and development purposes.
* 1978 BSD UNIX (Berkeley Software Distribution)
** Grad students at Berkeley modified and extended the AT&T code
** They bundled and released their add-ons for use at other universities
** Early development slowed due to licensing issues with AT&T and their lawsuits. AT&T wanted to monopolize and monetize this space.
** This project would eventually fork into three different projects: ~FreeBSD (1993), ~OpenBSD (1993), & ~NetBSD (1995)
*** The ~BSDs slowly fell out of favor as Linux gained more ground
* GNU project & the origins of Linux:
** GNU Project (GNU's not Unix) - Richard Stallman (1983) - Wanted to create a totally free OS unencumbered by commercial or licensing issues. The project started with the utilities.
*** FSF : Free Software Foundation (1985)
*** At MIT, he saw many MIT software developers get picked off by companies and sign restrictive non-disclosure agreements.
*** Many companies were now restricting access to Unix source code to limit modification and redistribution, facilitate hardware lock-in and push towards expanded commercialization.
*** This group believed software should be free to run, change, copy and modify so users are the ones in control, free from corporate control, and better software would then develop.
*** This led to the GNU license and brought a philosophy of freedom (freedom (speech), not price (beer) ). Users could access the source code and make changes, but companies could still charge for support.
*** The FSF kernel (GNU/Hurd) was taking too long to develop, though all other components (ie: the utilities) were complete.
** 1991 - The Linux Kernel:
** Linus Torvalds, a Finnish grad student, started working on a kernel for fun after getting impatient for a totally free kernel to work with due to all of the legal battles
*** Minix was a popular academic option. It was good for academics but not allowed for professional use
*** And Minix also required a fee and had a restrictive license
*** BSD was still somewhat encumbered by AT&T licensing issues and legal problems stalling development
*** Linux only had a kernel, not a complete operating system.
* Linux distributions:
** The GNU Project had utilities but no kernel. Linus Torvalds had a kernel but no utilities.
** So Linus provided the kernel (Linux kernel) to accompany FSF GNU utilities and components to make a Linux OS
** Different distributions (eg: Fedora, Gentoo, Debian, Ubuntu, etc) combine the Linux kernel, FSF utilities, and other applications in different ways and focus on different types of users.
*** Such as server distributions, desktop distributions, live distributions, or specialized distributions
** Early success was due to freedom - many other programmers were able to contribute code and ideas
* Early Commercial Distributions: (AIX, HPUX)
** Several commercial Unix distributions existed and only found in large enterprises. These were more popular decades ago and have lost ground to Linux.
A good article about the history of Unix/Linux: [[Did Linux Kill Commercial Unix|https://www.howtogeek.com/440147/did-linux-kill-commercial-unix/]]
! Interacting with the system
There are two ways to interact with a system: through a graphical interface (GUI) or the command line (CLI). Most of our work this semester will be conducted through the CLI.
!! Graphical User Interface (GUI)
* A desktop environment on top of OS. This is just another application and not baked into the OS like Windows
* Examples of GUI Desktop managers:
** Gnome
** KDE
** XFCE
* These window managers are much better for multitasking and necessary if you want to use graphical applications
* Some useful hotkeys:
**~Alt-F2 - Run a command
**~CTRL-ALT-Arrows - Change virtual desktops
**~CTRL-ALT-BKSP - Restart the window manager (if enabled)
** Navigating the menus - Much like what you're used to on either Windows or Mac
** Mouse: Highlight to copy, middle button to paste
*** This is the standard Unix/Linux way to copy/paste instead of having to press a key to do it. In putty, highlighting text copies it to the clipboard and clicking the right mouse button will paste to the terminal
!! Command Line Interface (CLI)
* Can be accessed from within the GUI, eg: the terminal program
* Or Console, which is accessed when you're sitting down at the keyboard and monitor on a system and not running a graphical environment
* Or through a virtual console (~CTRL-ALT-F[2-9]). Unix systems run many virtual consoles which can be accessed to run other tasks.
* Or accessed remotely, such as via SSH. We will be accessing our class shell server remotely to complete our work.
* Unix/Linux is primarily a Multi-user environment. Many users can easily log in concurrently and work simultaneously.
** About accounts:
*** Home directory - Every user has a home directory where they can store files
*** User ID - The ID number assigned to your account. It's these numbers which identify you as a user. Names, like user names or host names, are for people. The machines use the numbers.
*** Group ID - Users may belong to groups for shared resources. Everyone in this class is a member of the ''cs307'' group and can access this class's resources
*** Who am I? - List information about your user account: {{Command{id}}}
*** Who are you? - List information about other user's accounts: {{Command{id //username//}}}
*** Who is connected? - Show the users who are currently logged in: {{Command{w}}} or {{Command{who}}}
!! The Shell
The shell is our command processor that provides:
* An interpreter - it reads and interprets commands from the user,
** displays the shell prompt and waits for input
*** Case matters here! - The commands {{Command{id}}} and {{Command{ID}}} are two different commands. One will work and one does not exist. The same goes for any other file names.
** user interface for entering and processing commands from the user
** then works with the kernel to execute your commands
* A programming interface
** the shell is also a script interpreter for executing shell scripts
** a shell script is just a collection of commands you could execute in sequence on the command line
** This makes it much easier to automate or run a lot of commands at once
!! Different Shells
Different shells for different things: bourne, bash, csh, tcsh, korn
[>img[img/shell.jpg]]
The Shell is what users interact with on the command line. It receives and interprets commands.
[[Two main families|img/shells.jpg]] - bourne and ~C-Shell
Thompson shell, original unix shell, ends with AT&T 6th edition and replaced by the modern branches:
* Bourne Shell ({{Command{sh}}})
**written to replace limited abilities of original shell
**Oldest and most primitive
**Korn shell ({{Command{korn}}}) - Closed shell from Bell Labs
***Built to be a vast improvement over the bourne shell
***Adopted in future editions of AT&T Unix (8-10th editions)
***Became popular with commercial users as a higher end, more powerful shell, especially as a programming language
**Bash ({{Command{bash}}}) - FSF - ''B''ourne ''a''gain ''sh''ell
***Extends bourne shell while being free to distribute
***Free software, community supported, part of the GNU toolset.
*~C-Shell ({{Command{csh}}}) - Created by Bill Joy for the Berkeley Software Distribution (BSD) unix.
** Based on C Programming language. scripting commands are based on C statements
** BSD License, couldn't distribute freely
** TCSH ({{Command{tcsh}}}) -
*** Enhancement of the C-shell while being free from licenses
*** In public domain for academic users
* There's a few newer shells which are beginning to gain popularity
Which to use:
Shells are split into three camps: {{Command{bash}}} for Linux, {{Command{tcsh}}} in BSD branch, and {{Command{korn}}} for commercial distributions (IBM AIX and ~HP-UX)
What we'll be using this semester:
Interactive use: bash, since we're doing everything in Linux
Shell scripting: bourne for portability/compatibility or bash for extended features.
We can see available shells on a system with: {{Command{cat /etc/shells}}}
The shell is just a regular program, so anyone can design their own shell. You can also execute it by its command name to run a different shell.
!! Working with the shell
* Commands are entered at the shell prompt
* They have a standard syntax: {{Monospaced{''command_name'' [options] [arguments]}}}
** Command - what action to take
** Options - modify how the action is applied or how the command does its job
** Arguments - Provide additional info to the command, such as object identifiers, text strings, or file names
** Some options can have their own arguments (option arguments) to provide additional information for that option
*** For example, {{Command{mkdir -m 755 ~/open/}}} to create the directory named {{File{open}}} within your home directory with different starting permissions. Here, the {{Monospaced{755}}} is an argument to the {{Monospaced{-m}}} option.
** The components in a command string ''must'' always be separated by some form of whitespace
*** The command string {{Command{ls -l /tmp/}}} is correct where all three options are properly separated by whitespace. Whereas the command {{Command{ls-l/tmp/}}} is an invalid command that does not exist on the system. Notice the lack of whitespace in the second example.
** In documentation, brackets around a component show that component is optional and not required by the command. Consider these two examples:
*** {{Monospaced{grep [OPTIONS] PATTERN [FILE...]}}} - only the //PATTERN// argument is required.
*** {{Monospaced{ls [OPTION]... [FILE]...}}} - the command may be executed without specifying any options or arguments
**** The ellipsis (three dots) denote additional items can be added. For example, multiple files can be specified for the {{Command{grep}}} or {{Command{ls}}} commands.
** Example commands: {{Command{ls}}}, {{Command{date}}}, {{Command{cal}}}, {{Command{who}}}
* Many commands have default options or arguments
** {{Command{date}}} - by default, show the current date and time. Different options can be specified to alter the format the date is displayed in
** {{Command{cal}}} - by default, show a calendar for the current month. {{Command{cal 2024}}} will display the entire year
** {{Command{cd}}} - by default, change directory to the user's home directory. Specifying an argument will change to the specified directory instead.
* Combining options
** several options can be combined together, for example: {{Command{ ls -lrt }}} to display the contents of the current directory in long listing format, sorted by modification date, with the most recently accessed files at the bottom. There's three different options combined here.
* {{Monospaced{ - }}} vs {{Monospaced{ --word }}} options (eg: the {{Command{cut}}} command)
** Some options can be specified with a single dash and letter, eg {{Monospaced{ -d }}}
** Or with two dashes and a word, eg {{Monospaced{ --delimiter }}}
* Autocompletion - Enter the first few characters of a file or command and the shell will complete the rest. Press the tab key to assist with autocompletion
** This video contains example: https://www.youtube.com/watch?v=5mOHSBFuSy4
* Scrolling through previously executed commands:
** The keyboard up/down arrows can be used to cycle through previous commands
** Page-up can search more efficiently: type the first few letters of a previously executed command and press page-up to return to the last command which began with those characters. Continue pressing page-up to scroll through the list.
* The ~CTRL-C combo will generally cancel a running command
* You can also group multiple commands together with a {{Monospace{'';''}}}
** For example: {{Command{date ; cal}}} will run these two commands together
! Finding more information / UNIX Documentation
[>img[https://imgs.xkcd.com/comics/rtfm.png][https://xkcd.com/293/]]
* The unix manual / man pages are a great resource. Usage: {{Command{man [section] //command//}}}
** Example: {{Command{ man ls }}}
** Navigation:
*** move up and down the pages with space, {{Monospace{f}}}, and {{Monospace{b}}}
*** search down with {{Monospace{/}}}, up with {{Monospace{?}}}, or use {{Monospace{n}}} for the next match
*** {{Monospace{g}}} moves to the top of the page and {{Monospace{G}}} to the bottom
*** {{Monospace{q}}} to quit the manual
*** {{Monospace{h}}} for help with using the manual
* Man page chapters:
** Synopsis - Overview of the command, listing options and requirements. Optional items are contained within {{Monospace{''[ brackets ]''}}}
** Description - Description of actions performed by the command and detail information about all of the supported options
** Examples - Examples of common usage
**See Also - Other man pages to read for related information
**Check manpages for look, chmod, cut
*{{Command{man -k //keyword//}}} - search the unix manual
*Manual sections:
**1 - Commands
**2 - System Calls
**3 - Library Functions
**4 - Special Files
**5 - File Formats
**6 - Games
**7 - Misc Info
**8 - System administration
{{Note{''Note:'' When working with Unix documentation, items in ''[''brackets'']'' are optional.}}}
! Assignment
!! Read:
* Chapters 1 & 2 in //Harley Hahn's Guide to Unix and Linux//
!! Complete
* [[Lab 1|labs/lab1.pdf]] - Due Thursday, January 23
{{Warning{''Warning:'' Do not complete these lab assignment ~PDFs within your web browser. Download the files and open them in [[Acrobat Reader|https://get.adobe.com/reader/]] or a similar PDF document reader. Web browsers to not save form input appropriately and your responses may be lost or mangled during the collection workflow.}}}
Be sure to read the the instructions for submitting assignments and information about the labs in the [[Lab Assignments]] page. Assignments will only be accepted if they are properly submitted according to the instructions.
! Material
!! Read:
* Chapter 10 in //Harley Hahn's Guide to Unix and Linux//
Chapter 9 has helpful information on the Unix manual and {{Command{man}}} command.
! Entering Commands
* Commands are entered at the shell prompt
* Syntax: {{Command{//command_name options arguments//}}} (whitespace delimited)
** Command - what action to take
** Options - modify how the action is applied / how the command does its job
** Arguments - Provide additional info to the command (object identifiers, file names, etc)
** Some options can have arguments (option arguments)
*** {{Command{mkdir}}} with -m option
** Examples: {{Command{ls}}}, {{Command{date}}}, {{Command{cal}}}, {{Command{who}}}
* default options / arguments
** {{Command{date}}}, {{Command{cal}}}, {{Command{cd}}} commands
* combining options
*- vs - - dash options (file command)
* Arrows to access previous commands
* Autocompletion
** Tab key & ~CTRL-D
* command history
* type first 2 letters and hit up arrow
* Canceling a command with ~CTRL-C
* grouping commands with ;
** ex: {{Command{date ; cal}}}
Some commands we'll be using throughout the semester: [[Table of Commands]]
!!Signals
Can use Control-letter to send signals to the terminal
Typically abbreviated, ~CTRL-C or ^C
| !Sequence | !Action |
| ^A |Move cursor to start of line|
| ^E |Move cursor to end of line|
| ^C |Interrupt. Break out of what you're doing|
| ^D |eof. End of transmission, end of file|
| ^U |Erase entire input line|
| ^L |Clear screen above current line|
| ^E |Erase previous word|
! Finding information / UNIX Documentation
http://xkcd.com/293/
See Hahn chapter 9
*Usage: {{Command{man [section] //command//}}} - the unix manual / man pages
**Navigation : hahn page 195
***moving up and down with space, f and b
***search down with /, up with ?, n for next match
***g to top of page, G to bottom of page
***q to quit
***h for help
*Man page chapters:
**Synopsis - Overview of the command, listing options and requirements. Optional items are contained within [brackets]
**Description - Description of actions performed by the command and detail information about all of the supported options
**Examples - Examples of common usage
**See Also - Other man pages to read for related information
**Check manpages for look, chmod, cut
*{{Command{man -k //keyword//}}} - search the unix manual
*Manual sections:
**1 - Commands
**2 - System Calls
**3 - Library Functions
**4 - Special Files
**5 - File Formats
**6 - Games
**7 - Misc Info
**8 - System administration
! Assignment
!! Read:
* Chapter 10 in //Harley Hahn's Guide to Unix and Linux//
!! Complete
* [[Lab 2|labs/lab2.pdf]] - Due Sunday, January 26
! Material
!! History Substitution:
* Read: Chapter 13 - mainly the //History// sections on pages 302-306
** The {{Command{history}}} command is better than {{Command{fc}}}. Pay more attention to the former.
* Watch: Linux History Explained: https://www.youtube.com/watch?v=3BZzFRPYU_I
!! Variable Substitution:
* Read: Chapter 12, pp 255-269 (Stop at //C-Shell Family//
** We're using the bash shell. Focus on that one.
*Watch: Linux Shell Variables: https://www.youtube.com/watch?v=MbXofShhMv8
!! Command Substitution:
* Read: Chapter 13 - mainly the //Command Subsitution// section on pages 299-301
* Watch: Command substitution using backticks: https://www.youtube.com/watch?v=VOOeXV4HYSA
! Notes
What is the shell ?
We can do more then just enter commands and see the output. Several advanced features for increased productivity.
!! Metacharacters:
Page 280: ~ * [ ] ^ { } ? $ \ ' " / ! ` # < > | ; ( ) & %
* Be sure to track and understand what each of these are used for
!! Shell Substitutions
Substitutions are transformations the shell performs on input before a command string is fully executed. When the Unix shell encounters a substitution metacharacter, it will evaluate it to perform any substitutions before executing the full command string. These substitutions allow us to expand filenames, evaluate variables, recall previous commands, or use the result of one command as an argument to another. We already discussed filename substitution (file globbing). History substitution is very useful for recalling previous commands without having to retype it. Variable and command substitution are used extensively in shell scripting and have a useful place on the command line.
As you work with these substitutions, keep in mind the echo command can be used to preview the command string the shell will be executing after all substitutions are performed. Simply start your command string with {{Command{echo}}} to test it. We did this in Lab 23, #4 with the cat dog rabbit wombat question.
!!! History substitution
History substitution allows us to quickly recall previously executed commands. Previous commands are saved in a buffer which is written to the file ~/.bash_history upon logout. This allows history to be preserved across sessions and is useful for an administrator who needs to inspect activity of users on the system.
* Read: Chapter 13 - mainly the //History// sections on pages 302-306
** The {{Command{history}}} command is better than {{Command{fc}}}. Pay more attention to the former.
* Watch: Linux History Explained: https://www.youtube.com/watch?v=3BZzFRPYU_I
!!! Variable substitution
Variable substitution allows data to be stored for later use, much like any other programming language. The main application here is for shell configuration settings and for use in shell scripting. Variable substitution is not used as much as the other substitution forms when working directly on the command line.
* Read: Chapter 12, pp 255-269 (Stop at //C-Shell Family//
** We're using the bash shell. Focus on that one.
* Watch: Linux Shell Variables: https://www.youtube.com/watch?v=MbXofShhMv8
!!! Command substitution
Command substitution allows us to use the result of one command as an argument to another. Backticks or {{Command{$( )}}} are used to execute an inner command first. That inner command (including the backticks) is replaced by its output. The full command string is then executed.
''Important note:'' The backtick ''`'' and the single quote ''''' look rather similar. Be sure to approach this section with an eye for detail so you don't confuse the two.
Consider this example. I often work remotely and need to remotely power on my home Windows PC to retrieve some files or continue working with them. The wake-on-LAN function built into many motherboards allows for remote wake-up by broadcasting a specially crafted packet containing the system's MAC address to the broadcast address of the local subnet. Unix utilities exist to facilitate this. Their syntax is usually {{Command{//command// //~MAC-address//}}}.
I log into my home unix fileserver from a remote location via SSH. I have my PC's MAC address saved in a text file within {{File{/tmp/}}}:
{{{
# I can see that my PC's MAC address is saved in the text file named win7
root@trillian:/tmp # cat win7
c7:62:00:a2:25:55
# Rather then copy and paste, command substitution is a faster way to get that MAC address added to the command line as an argument to the wake command.
# The shell will first perform the substitution, replacing `cat win7` with the output of the cat command. Next, the full command string will be executed.
root@trillian:/tmp # wake `cat win7`
# I can preview the full result of my substitution by prefixing the command string with echo to see what will really be executed by the shell
root@trillian:/tmp # echo wake `cat win7`
wake c7:62:00:a2:25:55
}}}
An even better way involves combing history and command substitution:
{{{
# Preview my file, make sure the MAC address looks good
root@trillian:/tmp # cat win7
c7:62:00:a2:25:55
# History substitution will be used first to replace !! with the last executed command (cat win7).
# Next, command substitution will replace the backticks with the result of executing the enclosed command (the MAC address)
# Finally, the full wake command string with the MAC address added as an argument will wake up my Windows PC.
root@trillian:/tmp # wake `!!`
}}}
* Read:
* Read: Chapter 13 - mainly the //Command Subsitution// section on pages 299-301
* Watch: Command substitution using backticks: https://www.youtube.com/watch?v=VOOeXV4HYSA
! Assignment
!! Complete:
* Complete [[Lab 35|labs/lab35.pdf]] & [[Lab 36|labs/lab36.pdf]]
! Material
!! Read:
* Chapter 23 in //Harley Hahn's Guide to Unix and Linux//
! Review
Lab submission and collection workflow
Command components:
* Command, options, and arguments
Man pages
* Sections
* Examples (eg, awk)
* Searching
Efficiently navigating the shell
* Page-up, up arrows, tab completion,
* ~CTRL-R, ~CTRL-C, ~CTRL-D
! UNIX Files
Navigating the filesystem is at the core of working with the Unix command line. Explore our shell server using the {{Command{cd}}}, {{Command{ls}}}, and {{Command{pwd}}} commands. Files for our class and your labs can be found within the {{File{/opt/pub/cs307/}}} directory. Use the material introduced in this chapter to explore the filesystem on the shell server, especially the directories within {{File{/opt/pub/cs307/}}}.
Everything on a Linux system is either a file or a process
* Defined: A file is anything that can be a source or destination of data.
!! File types: (ls will show the type)
* ''Ordinary files'' (also called regular files) - items such as text files, programs, and images
** {{Command{file}}} command - This command can be used to display a file's type
*** eg: {{Command{file /usr/bin/ls}}}
** {{Command{strings}}} command - This command can be used to extract ascii strings from a binary file
* ''Directory files'' - special files that contain lists of files and other directories. How files are organized on the system.
** Standard conventions: A file written with a trailing slash (eg: {{File{/opt/pub/cs307/}}} refers to a directory.
** Filesystem Root - Highest level of the file system = {{File{ / }}}
*** The filesystem has a tree-like structure, starting at its root and branching out as you traverse into the sub-directories.
** Navigate directories with the {{Command{ cd }}} command
*** eg: {{Command{ cd /opt/pub/cs307/ }}}
*** The {{Command{ cd }}} command's default argument will change to your home directory
**** Some commands, like {{Command{ cd}}}, have a default argument. The command will act on the default argument if you do not specify one.
*** {{Command{cd -}}} will change to the last directory you were in. Note the dash after the {{Command{ cd }}} command.
** Display file metadata (eg, permissions and date information) on a directory with {{Command{ls -ld}}}
*** Example: {{Command{ ls -ld /opt/pub/cs307/ }}}
** Special directories contained within every directory on the system:
*** {{File{.}}} = Refers to the present working directory. (The directory you are currently in)
*** {{File{..}}} = Refers to the parent directory. See warning note below.
** Your home directory. A place for your files on the system. Referred to with the shortcut symbol ({{File{~}}} or the variable $HOME)
*** Either use it alone to refer to your home directory, eg: {{Command{ls ~}}}
*** Or with a username to refer to another user's home directory, eg: {{Command{ls ~//username//}}}
** Relative & absolute path names
*** Absolute path - a path that starts from the root of the filesystem. It will always begin with {{File{ / }}}, eg: {{File{/opt/pub/cs307/submit/}}}
*** Relative path - a path that starts from your current directory, eg: {{File{ cs307/submit}}} (notice the lack of a {{Monospaced{ / }}} at the beginning of this path).
** Working directory
*** The //current working directory// is the directory you are currently located in at the shell prompt.
*** The command {{Command{pwd}}} (print working directory) will display the full path of your current working directory to the screen. This helps keep track of where you are on the system.
** Obtain disk usage of a directory with the {{Command{du}}} command, eg: {{Command{ du -sh ~ }}}
* ''Symbolic Links'' - special files that are pointers to other files
* ''Hardware devices'' - storage medium (hard drive, DVD drive, flash drives, etc), display, network cards, etc.
** Character devices - device that reads or writes data one character at a time
** Block device - device that reads or writes data one block at a time
* ''FIFO'' (aka named pipe) - Used for interprocess communication
* ''Socket'' - Used for network communication
{{Warning{''Note:'' The special directory {{File{..}}} refers to the ''parent directory'', not //previous directory//. The word previous is ambiguous and could mean the last directory you were in. The last directory you were in could be anywhere on the filesystem. Referring to the special directory {{File{..}}} as //previous directory// will be considered incorrect. }}}
!! File and directory names
Good file naming practices:
* File names can be any sequence of ASCII characters up to 255 characters
* Start your file names with an alphabetic character
* Try to avoid spaces. Instead use dividers to separate parts of the name, such as {{Monospaced{ _ - : . }}}
* Use an extension that describes the file type
** For example, the file extension {{File{ homebackup_december.tgz }}} suggests this is a gzip-compressed tar archive.
* Files beginning with a dot are hidden from normal view
** These are typically configuration files, like {{File{.bash_profile}}} or {{File{.bashrc}}}
* Avoid special characters (shell metacharacters) in your file names, such as: {{Monospaced{ & * \ | [ ] { } < > ( ) # ? ' " / ; ^ ! ~ % ` }}}
** All of these symbols mean something special to the shell. Keep track of what they mean as they are introduced during the semester. [[Shell Metacharacter Table|handouts/ShellMetacharacterTable.pdf]]
** If special characters were used, escape them with a {{Monospaced{ \ }}}
*** Example: {{Command{vi commands\&examples.txt}}}
** Put quotes around your file name if spaces must be used
*** Example: {{Command{vi "Long File Name.txt"}}}
** We'll discuss escaping, quoting, and metacharacters in more detail later
!! Basic file manipulation
!!! Listing files - {{Command{ls}}}
The {{Command{ls}}} command will list the contents of a directory. Extra options can be used to alter the default behavior of the {{Command{ls}}} command:
* {{Command{-a}}} - This option will include hidden files in the output
* {{Command{-l}}} - This option will display the output in //long listing// format. Additional information about the files will be displayed. Display your files with a long listing is preferred so you a presented with the additional detail.
! Assignment
!! Read:
* Chapter 23 in //Harley Hahn's Guide to Unix and Linux//
!! Complete
* [[Lab 3|labs/lab3.pdf]] & [[Lab 4|labs/lab4.pdf]]
! Assignment
We'll continue our filesystem work from the first half of the week
!! Complete
* [[Lab 5|labs/lab5.pdf]]
! Material
!! Read
* Chapter 24 in //Harley Hahn's Guide to Unix and Linux//
** You can skip the //Globbing with Wildcards// section from pages 697 to 702 for now. We'll focus on this later in the week
!! Watch:
* Creating and Deleting files and directories: https://www.youtube.com/watch?v=91FhiTyEaCU
* Moving and copying files: https://www.youtube.com/watch?v=GKEGNdNIQrw
! Working with Files & Directories
Every operating system has a basic set of utilities to manipulate files and directories on the command line. This week's reading assignment will introduce those commands in the Linux operating system.
!! Basic file manipulation commands
Rename and move files - {{Command{mv}}}
Copy files - {{Command{cp}}}
* Recursive copy: {{Command{cp -R}}}
Create directories - {{Command{mkdir}}}
Delete files and directories - {{Command{rm}}} & {{Command{rmdir}}}
* Difference between unlink & delete - Removing a file doesn't actually delete it from the system, it only marks the space it was occupying as available for reuse.
* This is more appropriately called "unlinking". We're only removing the //link// between the filesystem and the data blocks. The actual data will still reside on the disk and can be forensically recovered.
* The {{Command{srm}}} or {{Command{shred}}} commands will actually destroy a file by overwriting its data blocks before unlinking it.
** These commands are not installed by default on most systems
** Securely wiping a file is more resource intensive than simply unlinking it because random data must first be generated and then written to disk.
View the contents of files with {{Command{cat}}} and {{Command{less}}} (or {{Command{more}}}, an old version of {{Command{less}}})
** [[less quick reference]]
Edit text files:
* The standard Unix text editors are {{Command{nano}}} (Basic and easy to use) and {{Command{vi}}} (more powerful, but harder to get used to)
* {{Command{vi}}} comes installed on every Unix/Linux system. The {{Command{nano}}} editor may need to be installed separately.
* {{Command{vi}}} has a learning curve, but is the professional text editor. If you'll be doing this work in the future, learning {{Command{vi}}} is well worth the time investment.
** Some {{Command{vi}}} handouts: [[Command line summary handout|handouts/UnixCommandSummary.pdf]] (last page) & [[vi diagram handout|handouts/viDiagram.pdf]]
!! Other useful commands:
* {{Command{touch}}} - create an empty file
* {{Command{file}}} - examine a file to identify its type
! Assignment
!! Read
* Chapter 24 in //Harley Hahn's Guide to Unix and Linux//
** You can skip the //Globbing with Wildcards// section from pages 697 to 702 for now. We'll focus on this later in the week
!! Watch:
* Creating and Deleting files and directories: https://www.youtube.com/watch?v=91FhiTyEaCU
* Moving and copying files: https://www.youtube.com/watch?v=GKEGNdNIQrw
!! Complete:
* [[Lab 6|labs/lab6.pdf]] & [[Lab 7|labs/lab7.pdf]]
! Material
!! Read:
* Chapter 24 in //Harley Hahn's Guide to Unix and Linux//
** With particular focus on //Globbing with Wildcards// from pages 697 to 702
!! Watch:
* File Globbing: https://www.youtube.com/watch?v=QIysdjpiLcA
* Brace Expansion: https://www.youtube.com/watch?v=LGzSnVYS2J4
! File Globbing & Wildcards
So far, when working with files we've specified one filename at a time on the command line. Other shell metacharacters exist to identify files by patterns in their filenames and work with them as a group. Suppose we want to move all files that end in ''.jpg'' to a particular location, or delete all files that contain the string ''temp'' in their filename. If there's thousands of them, it's going to be very tedious to have to list each of the files individually. Or, we can instead use special file wildcard metacharacters to concisely identify these groups of files by common characteristics. This is referred to as ''filename substitution'' or ''file globbing''.
!! Filename substitution
Metacharacters associated with file names: {{Monospaced{''~ * ? [ ] [^ ] { }''}}}
* {{Monospaced{''*''}}} = match any sequence of 0 or more characters
* {{Monospaced{''?''}}} = match any single character.
** It's important to note the ''?'' is a mandatory position which must be filled. It's not optional like the ''{{Monospaced{''*''}}}'' is. So if you type {{Command{ls /bin/d??}}}, you'll see a list of all files in {{File{/bin/}}} which begin with a ''d'' and are exactly three letters in length. You will not see the files which are shorter then three characters, such as the {{Command{df}}} command or longer than three characters such as the {{Command{diff}}} command. Both ''?'' must contain a character.
* {{Monospaced{''[ ]''}}} - match any of the enclosed characters in the set (eg: ''[abcd]''), or match a range (eg: ''[a-z] [~A-Z] [0-9] [e-q]'')
** The {{Monospaced{''[ ]''}}} brackets are similar to the ''?'' in that they specify a single, mandatory character. Where the ''?'' wildcard can represent any character, the brackets allow us to be a little more specific with what that single character may be.
** The {{Monospaced{''-''}}} within the {{Monospaced{''[ ]''}}} specifies the range of characters based on its position in the [[ascii chart|img/ascii-chart.gif]]. For example, {{Monospaced{''[4-6]''}}} or {{Monospaced{''[;-?]''}}} to match the characters {{Monospaced{''; < = > ?''}}} (ascii 59 to ascii 63).
*** Ranges and lists of characters can be combined. The gobbing pattern {{Monospaced{''[ac5-8()]''}}} will match the letters {{Monospaced{''a''}}} and {{Monospaced{''c''}}}, the numbers {{Monospaced{''5''}}} through {{Monospaced{''8''}}}, and the two parenthesis.
** {{Monospaced{''[^ ]''}}} - match any character //not// enclosed in the set or range (eg: ''[^abcd]'' or ''[^a-z]''). The notation ''[! ]'' is sometimes used but not universally recognized. Use ''[^ ]'' instead. The labs will all use ''[^ ]''.
* {{Monospaced{''{ }''}}} - Brace Expansion. Expand comma separated strings to create multiple text strings from a pattern. Example: {{Command{mkdir -p {one,two,three}/examples}}} will create the directories {{File{one/examples}}}, {{File{two/examples}}}, and {{File{three/examples}}}.
{{Note{''Note:'' Negation should only be used when it is the best possible method for solving the problem, not as a way to be lazy. If the question asks to list a particular set of files, try to find a way to target just those files. Negation is ideal when the question includes a negation term, such as the wording //except// or //do not//. When negation is abused, often files are matched which did not intend to be. }}}
{{Warning{''Warning:'' Try to be as specific as possible when you are using wildcards. It's best practice to type out the static text and only use wildcards for the dynamic part of what you are trying to match. For example, if I am trying to match the files {{File{data1.txt}}}, {{File{data2.txt}}}, {{File{data3.txt}}}, and {{File{data4.txt}}}, the best file globbing pattern would be {{Command{data[1-4].txt}}}. It is as specific as possible and includes the static portions of the filename. Using {{Command{data?.txt}}} would inadvertently match {{File{data5.txt}}} and {{Command{*[1-4].txt}}} could match something else entirely. Even if those files are not currently in the directory, they might be later. Don't be lazy with your file globbing patterns!}}}
!!! Examples - Display all files who's names:
Begin with the letter f: {{Command{ls f*}}}
(read as: list files which begin with an ''f'' followed by ''0 or more characters'')
Contain a number: {{Command{ls *[0-9]*}}}
(read as: list all files which may begin with ''0 or more characters'', followed by ''any number'', and end with ''0 or more characters'')
begin with an uppercase letter: {{Command{ls [~A-Z]*}}}
begin with the letter a, b, or c: {{Command{ls [abc]*}}}
begin with the letter a, b, or c and is exactly two characters in length: {{Command{ls [abc]?}}}
do not begin with the letter a, b, or c: {{Command{ls [^abc]*}}}
end with a number from 2 to 9 or a letter from w to z: {{Command{ls *[2-9w-z]}}}
are exactly two characters long and begin with a lowercase letter: {{Command{ls [a-z]?}}}
being with string one, end with string three, and contain string two somewhere in between: {{Command{ls one*two*three}}}
{{Warning{''Warning:'' Working on the command line requires an eye for detail. We're starting to get to the point where that detail really matters. There's a huge difference between the commands {{Command{rm *lab6*}}} and {{Command{rm * lab6*}}}. One stray space and you're going to be in for some missing labs. Take a second look at your commands before executing them and be very deliberate with what you're running. Remember - Working on the command line is precise. Every character matters and we must have an eye for detail!}}}
!! Substitutions
Through use of shell metacharacters, substitutions are transformations performed by the shell on command line input prior to executing a command string. File globbing is one of the 5 types of shell substitutions.
It's important to understand the order of operations here. In the math formula 5 + 6 * 7, our calculations are not automatically performed left to right. There is a set order of operations that calls for the multiplication to be performed first. The same idea applies to entering command line input. First, all substitutions are performed by the shell, then your command string is executed.
Consider the command {{Command{ls *.jpg}}}
The shell recognizes that we're performing a substitution (eg: {{File{*.jpg}}}) and replaces {{File{*.jpg}}} in the command string with a list of all files that match the pattern.
Next, the {{Command{ls}}} command is executed with the list of files as arguments
A great way to preview the result of any substitutions is with the {{Command{echo}}} command. The {{Command{echo}}} command repeats back to the screen whatever you give it as an argument. For example:
{{{
[merantn@shell ~]$ echo hello cs307
hello cs307
[merantn@shell ~]$ cd /opt/pub/cs307/data/lab8
[merantn@shell lab8]$ echo rm IMG_126?.jpg
rm IMG_1260.jpg IMG_1261.jpg IMG_1262.jpg IMG_1263.jpg IMG_1264.jpg IMG_1265.jpg IMG_1266.jpg IMG_1267.jpg IMG_1268.jpg IMG_1269.jpg
}}}
So if I have a complex or risky substitution, I may want to prefix the command string with the {{Command{echo}}} command to preview it before its executed:
eg: Change to {{File{/opt/pub/307/submit/}}} and run: {{Command{echo ls *lab[1-3]*}}} to see what substitution is being performed and the actual command string about to be executed. Don't forget to prefix it with {{Command{echo}}}!
These file globbing substitution examples are pretty tame, but this trick with the {{Command{echo}}} command will come in very handy later on when we get to more complicated substitutions.
! Assignment
!! Read:
* Chapter 24 in //Harley Hahn's Guide to Unix and Linux//
** With particular focus on //Globbing with Wildcards// from pages 697 to 702
!! Watch:
* File Globbing: https://www.youtube.com/watch?v=QIysdjpiLcA
* Brace Expansion: https://www.youtube.com/watch?v=LGzSnVYS2J4
!! Complete:
* [[Lab 8|labs/lab8.pdf]] & [[Lab 9|labs/lab9.pdf]]
! Improving soft skills
Our first few labs brought up some soft-skill gaps. Advancements here will be important for this course and your future careers:
# Read the directions thoroughly
# Ensure you're meeting all requirements
# Be thorough in your writing
# Consider usability - presentation matters
# Use proper terms
# Test your theories
!! 1. Read the directions thoroughly
Lab 7 contained this phrase in bold within the directions at the top of the page: ''Commands executed must function from anywhere on the system.''
A large portion of the class ignored that and lost points from several of the questions.
Question 1 was a good example:
<<<
1. //Create an empty file named ''source'' @@in your home directory@@ using a single command.//
<<<
I saw many responses with a solution similar to this: {{Command{touch source}}}
That command gets the job done, but //only// if your current working directory is your home directory. What if you're somewhere else in the filesystem? The full path to the file we wish to create must be included to indicate exactly where on the system it should be created. Either the solution {{Command{touch /home/cs307///username///source}}} or {{Command{touch ~/source}}} will properly include the path to your home directory and provide a command which will work from __anywhere on the system__.
!! 2. Ensure you're meeting all requirements
The directions for groups of questions or instructions within the questions themselves will have small details in their requirements which will need to be addressed. Some questions will ask for both the command and output. Students often overlook the need for output and only supply the command.
It's always wise to read the directions for the lab or instructions for a question, add your responses, then re-read the details to ensure your responses match what is requested.
Lab 3, Question 1 was a good example:
<<<
3. //A command string may be composed of three different components: The command, options, and arguments. Explain the purpose of each component @@and what must separate them@@. Provide an example containing all three components to further illustrate your point, preferably not one already demonstrated in the book.//
<<<
Quite a few forgot to mention that whitespace must separate our command, options, and arguments and lost points. It might be helpful to use your PDF reader's highlight function to highlight these requirements as you read the question to help ensure you're addressing all of them.
!! 3. Be thorough in your writing
We're not in the classroom where I can easily ask you to clarify your responses. In writing, you must be thorough so the reader understands your message. This is important now for grading to convey that you fully understand what's going on and will be important later when it comes time for you to create documentation or explain things to colleagues. I encounter far too much poor "professional" documentation at my day job which is either vague or omits critical details. Lab 5, questions 8 and 9 highlighted this. Too many points were lost unnecessarily do to incomplete explanations.
I provided an example for the first command in question 8:
<<<
8. //Summarize the actions performed by the following commands (don’t just copy the output)://
<<<
|ls | List the contents of the current directory |
This explanation concisely lists the action which is taken (list the contents) and the object which is acted upon (the current directory).
For the second command, {{Command{ls -a}}}, a common response I received was //list hidden files//. This response omits two critical details: Are //only// hidden files to be listed? Which hidden files are we listing? A thorough response would be something like: //list all files, including hidden files, in the currently working directory//. Here we're concisely explaining all of the components of this command: What the command does (list all files), the option provided (including hidden files), and the target (in the current working directory).
Even worse, for the command {{Command{ls /}}}, I received several responses which were simply //root directory//. What about it? What's the action that's being taken? Here, the action taken upon the ''@@root of the filesystem@@'' is omitted completely. A response for this command should be something like //list the contents of the ''@@root of the filesystem@@''//. We're explaining both the command and the target.
Notice the highlighted text above and the output of the command {{Command{ls /}}}:
{{{
[merantn@lab ~]$ ls /
bin dev etc lib media opt root sbin sys usr
boot entropy home lib64 mnt proc run srv tmp var
}}}
There is an entry in this output named {{File{//root//}}}. Using //root directory// in the response to that question is ambiguous. Does //root directory// mean {{File{/}}} or {{File{/root/}}}? Referring to {{File{/}}} as //the root of the filesystem// helps eliminate that problem.
Another example: For the command {{Command{ls .}}}, I received the response //lists the current directory//. The command {{Command{pwd}}} will display the current directory. By default, the {{Command{ls}}} command lists the //contents of// its target. There's a big difference between the two.
Yet another example: For #9, I occasionally receive the terse response //Changes to tmp directory// as a response to the commands {{Command{cd /tmp/}}} and {{Command{cd /var/tmp/}}}. Those are two different paths. How can the answer be the same for both of them? Be specific - you're provided with an absolute path in the question, so it might be a good idea to use the same absolute path in the responses.
We'll be in this situation throughout the semester. Be sure your responses are thorough and do not omit the critical details. Even if you never touch the Linux command line again, improving your writing will be a universal skill that will serve you well later.
!! 4. Consider usability - presentation matters
Usability and good presentation should be part of everything you produce. Lab 3, #6 provides a good example:
<<<
6. //The Unix manual is an excellent system resource to learn more about commands on the system or as a quick reference for their usage. Use what you learned in the first three chapters to identify four commands on the shell server which were not already discussed in the book or class website. Research these commands and write a summary of each below. Include the name of the command, a summary of its function, and an example of its usage.//
<<<
Of these two options, one is clearly presented better and easier to read than the other. Which would you prefer reading? Try to avoid large blocks of text when possible; space out separate items to improve readability.
{{Monospaced{
The 'grep' command searches for a specified pattern in files or input and outputs the lines that contain the pattern. grep "error" server_logs.txt searches for the word "error" in the file "server_logs.txt". chmod: This command changes the file mode bits (permissions) of each given file, directory, or symbolic link. chmod 755 script.sh sets the permissions of "script.sh" to "755" (read, write, and execute for owner; read and execute for group and others). The 'tail' command outputs the last part of files. It's commonly used to view the newest entries in log files. tail -n 20 server_logs.txt displays the last 20 lines of the file "server_logs.txt". du - This command is used to estimate file and directory space usage. du -sh /home/user/Documents displays the total size of the "Documents" directory in a human-readable format.
}}}
{{Monospaced{
1. grep: The 'grep' command searches for a specified pattern in files or input and outputs the lines that contain the pattern.
- Example: grep "error" server_logs.txt searches for the word "error" in the file "server_logs.txt" and displays those lines to the screen
2. chmod: This command changes the file mode bits (permissions) of each given file, directory, or symbolic link.
- Example: chmod 755 script.sh sets the permissions of the file "script.sh" to "755" (read, write, and execute for owner; read and execute for group and others).
3. tail: The 'tail' command outputs the last part of files. It's commonly used to view the newest entries in log files.
- Example: tail -n 20 server_logs.txt displays the last 20 lines of the file "server_logs.txt" to the screen.
4. du (Disk Usage): This command is used to estimate file and directory space usage.
- Example: du -sh /home/user/Documents displays the total size of the "Documents" directory in a human-readable format.
}}}
!! 5. Use proper terms
Lab 5 questions 8 and 9 asked you to explain what the commands {{Command{ls ..}}} and {{Command{cd ..}}} will do. I received a lot of responses that contained the phrase "//previous directory//" to refer to the {{File{..}}} portion of that command string. //Previous directory// is ambiguous. To me, that refers to the last directory you were in. The directory {{File{..}}} is a special directory that refers to the ''//parent//'' of a directory, so the command {{Command{ls ..}}} will //display the contents of the parent of the current working directory//. The command {{Command{cd ..}}} will change you to the //parent of your current working directory// whereas {{Command{cd -}}} will //return you to the previous directory you were in//.
!! 6. Test your theories
Lab 6, question 7 was a good example of this problem:
<<<
//7. Explain each of the three arguments and the result of executing the following command string: {{Command{mv one two three}}}.//
<<<
I receive some pretty wild responses to this one. The most common two incorrect answers are:
* //move file one to file two and file two to file three//
* //move files one and two to directory three. __Directory three will be created if it does not exist.__//
We have a lab environment available to us for practicing the material and testing your solutions. If these answers were tested, it would be very obvious they are incorrect. Submitting untested solutions will especially be a problem later in the semester when we get to more complicated material. Don't be lazy and just guess. I tend to grade far more harshly when I encounter such obviously incorrect responses.
! Assignment
!! File Globbing 2
We'll use the first half of this week to work on File Globbing a bit more. Be sure to clear up any outstanding questions or missed lab problems in Discord. We'll be using this concept a lot later; it will be important to have a good grasp of this material.
!!! Complete:
* [[Lab 10|labs/lab10.pdf]]
!! Working with command documentation
!!! Read:
* Chapter 9, Documentation
* Chapter 10, pp 235 & 236 Command Syntax. Pay particular attention to the part about notation and be sure to know how to interpret the documented usage of these commands:
{{{
cd [-L|[-P[-e]]] [dir]
vs.
mkdir [OPTION]... DIRECTORY...
}}}
! Material
!! Read:
* Chapter 25 in //Harley Hahn's Guide to Unix and Linux//
** Begin at //The Idea of a Link// on page 740
** Read through the end of //Using Symbolic Links With Directories// ending on the top of page 747
!! Watch:
* Links: https://www.youtube.com/watch?v=lW_V8oFxQgA
! Links
Links are a mechanism to connect two files together. There are two different types of links within the Unix environment:
# ''Hard links''
# ''Symbolic links''
The two differ in how the link connects to its target. Those differences impact the situations in which each can be used and when one is more appropriate than the other.
Using the following directory listing as an example:
{{{
[merantn@shell dict]$ pwd
/usr/share/dict
[merantn@shell dict]$ ls -l
total 9680
-rw-r--r--. 2 root root 4953680 Jun 10 2014 linux.words
-rw-r--r--. 2 root root 4953680 Jun 10 2014 wordlist
lrwxrwxrwx. 1 root root 11 Feb 4 21:07 words -> linux.words
}}}
We can identify the file named {{File{words}}} as a ''symbolic link'' due to the letter ''{{Monospaced{l}}}'' at the beginning of the line and the arrow pointing to its target. A symbolic link is a special type of file that only contains the path to the file it is pointing to.
''Hard links'' are directory entries which point to the same inode. An inode is a filesystem data structure which contains information about the file and where its blocks can be found on the underlying storage medium. Thus, hard links point directly to the same place on the disk. We can tell that the files {{File{linux.words}}} and {{File{wordlist}}} are hard links because of the number ''2'' in the second column (from the {{Command{ls -l}}} command output above; third column below). This is the link count. It will increase as more hard links are created. A file isn't truly deleted until its link count reaches zero.
{{{
total 9680
19220022 -rw-r--r--. 2 root root 4953680 Oct 14 2019 linux.words
19220022 -rw-r--r--. 2 root root 4953680 Oct 14 2019 wordlist
19220023 lrwxrwxrwx. 1 root root 11 Oct 14 2019 words -> linux.words
}}}
In the above output, adding the ''{{Monospaced{-i}}}'' flag to the {{Command{ls}}} command shows the inode number for the file. We can see the files {{File{linux.words}}} and {{File{wordlist}}} are both hard links pointing to the same place on the disk because they both are pointing to the same inode number. Identifying hard links by inode number will be more difficult if the links are not in the same directory.
This graphic may help visualize the relationship between the different link types and their targets.
[img[img/links.png]]
!!! Link commands:
* Create links with the {{Command{ln}}} command:
** Create a hard link: {{Command{ ln //file// //link//}}}
** Add the {{Command{ -s }}} option to create a symbolic link: {{Command{ ln -s //file// //link//}}}
* In each case, {{Monospaced{ //file// }}} is the target file that currently exists and {{Monospaced{ //link// }}} is the name of the new link you are creating.
The textbook pages listed at the top will contain more information about these two link types.
! Assignment
!! Read
* Chapter 25 in //Harley Hahn's Guide to Unix and Linux//
** Begin at //Multiple Links to the Same File// on page 741
** Read through the end of //Using Symbolic Links With Directories// ending on the top of page 747
!! Watch:
* Links - https://www.youtube.com/watch?v=lW_V8oFxQgA
!! Complete:
* [[Lab 11|labs/lab11.pdf]]
! Material
!! File Permissions:
* Read:
** Chapter 25 in //Harley Hahn's Guide to Unix and Linux//
*** Begin at //How UNIX Maintains File Permissions// on page 732
*** Stop at //The Idea of a Link// on page 740
* Watch
** File Permissions: https://www.youtube.com/watch?v=8SkN7UofOww
** Umask: https://www.youtube.com/watch?v=xz2_1UEweKM
! Notes
!! File Permissions
The Unix operating system has multiple levels of securing access to resources. We can restrict who can access the system through userids and login credentials, we can limit who can become the superuser and act as the administrator of the system, we can control who can access certain directories on the system, and we can control access to files. The first two are items for an administrator to configure, but the latter two regular users can control for files that they own. Being able to restrict access to certain files is a critical function of a multi-user system. For example, we restrict access to the lab assignments everyone is uploading so no one else peeks at your work. Certain sensitive system files are restricted to keep the system more secure.
Hopefully by now we're comfortable navigating the filesystem and identifying files by name, both individually and in groups. Next I'd like to examine how we can manipulate the file's permissions.
Permissions can be set based on three different tiers:
* User - the owner of the file
* Group - a group that has access to the file
* Others - everyone else on the system
And three different permissions can be set on each file
* Read - The ability to read a file or list the contents of a directory
* Write - The ability to modify content of a file or create files in a directory
* Execute - The ability to run a program or access a directory
Chapter 9 in the The Linux Command Line will discuss permissions in detail.
This youtube video is a good permission overview: [[File Permissions|https://www.youtube.com/watch?v=8SkN7UofOww]]
!!! File & Directory Permissions
The following tables and graphics can serve as a quick reference:
!! File & Directory Permissions
|!Type|!File|!Directory|
| read (4) | read contents | List directory |
| write (2) | change / delete file | Add files |
| execute (1) | run executable | cd into |
!!!! chmod
The {{Command{chmod}}} command can be used to change permissions for existing files.
* using octal codes
** Read (4), Write (2), and Execute (1)
** Three positions: user, group, and others
* using symbolic codes
** who:
*** u - user
*** g - group
*** o - others
*** a = all positions
** operator:
*** = explicitly set
*** + add permission
*** - remove permission
** permission:
*** r = read
*** w = write
*** x = execute
{{Note{''Note:'' Use symbolic abbreviations when making changes to permissions without consideration to what is already set, eg: when adding or removing permissions. The use of octal codes requires all permissions be completely reset - a user cannot set, add, or remove individual permission settings.
For example, suppose I only want to __add__ write permissions for the group. Without knowing what the permissions currently are, I have to use symbolic notation to modify the permissions on the file. In this case with {{Command{chmod g+w //file//}}}
If the lab question asks you to ''set'' permissions, use __octal codes__. If it asks you to ''add or remove'', use __symbolic__ abbreviations.
}}}
<html><center><img src="img/chmod1.png" alt=""><BR><BR><HR width="75%"><img src="img/chmod2.png" alt=""></center></html>
!!! umask
The {{Command{umask}}} command can be used to establish default permissions for all newly created files.
* umask - user mask - which permissions to restrict. (mask = remove)
* start with full permissions 777
* The umask value is which bits to remove.
* The execute bit (1) will automatically be subtracted from all positions for regular files
* Making a new regular text file executable must be a manual task
A mask refers to bits to be removed. If we do not want newly created files to have write permissions for the group or others, we need to mask 2 from the group and others positions, resulting in a umask of 22.
Examples:
A umask value of 22 will set default permission for new files to 644 (777 - 22 - 111) and directories to 755 (777 - 22)
A umask value of 77 will set default permission for new files to 600 (777 - 77 - 111) and directories to 700 (777 - 77)
''Note:'' Newly created files are not granted execute automatically despite the umask value.
! Assignment
!! File Permissions:
* Read:
** Chapter 25 in //Harley Hahn's Guide to Unix and Linux//
*** Begin at //How UNIX Maintains File Permissions// on page 732
*** Stop at //The Idea of a Link// on page 740
* Watch
** File Permissions: https://www.youtube.com/watch?v=8SkN7UofOww
** Umask: https://www.youtube.com/watch?v=xz2_1UEweKM
* Complete:
** [[Lab 12|labs/lab12.pdf]] & [[Lab 13|labs/lab13.pdf]]
! Material
!! Read:
* Chapter 15 in //Harley Hahn's Guide to Unix and Linux//
* Chapter 23, pages 633 & 634
** //Read the Special Files for ~Pseudo-Devices// section
!! Watch
* Linux Sysadmin Basics 04 -- Shell Features -- Pipes and Redirection - https://www.youtube.com/watch?v=-Z5tCri-QlI
Please make use of the discussion boards if you run into any trouble with these commands, especially later week when we need to start combining them in more complex ways.
Most shell metacharacters (the symbols on your keyboard) have a special meaning. Compiling a list of them with an explanation and example usage in this [[Shell Metacharacter Table|handouts/ShellMetacharacterTable.pdf]] as they are introduced might be helpful.
! Notes
A lot of the power of the Unix environment comes from single-purpose commands. The filter commands we are about to introduce are great examples. By combining these single-purpose commands we can build flexible and customized solutions to solve a wide range of problems.
By default, output from a command such as our text filters is displayed to the screen. By redirecting where that output is sent, we can chain commands together to creatively solve more complex problems.
Redirecting standard I/O is how we move data between filters and files. The following diagram illustrates our options:
[>img[img/stdout.png]]
This video explains the basics: https://www.youtube.com/watch?v=-Z5tCri-QlI
!! Standard input and standard output:
* Every filter should be able to accept input from any source and write output to any target
* Input can come from the keyboard, from another file, or from the output of another program
* Output can be displayed to the screen, can be saved to a file, or sent as input to another program
* This gives us great flexibility when combined with the simple approach to our tools
The standard source, Standard Input, is commonly abbreviated as STDIN. The two output destinations, Standard Output and Standard Error, are commonly abbreviated as STDOUT and STDERR, respectively. Collectively, all three are abbreviated as STDIO.
{{Warning{''Warning:'' Not every utility will accept input on STDIN, not every utility will output to STDOUT! It is important to keep this in mind. Generally, most system utilities such as {{Command{ls}}}, {{Command{mkdir}}}, and {{Command{cp}}} do not accept input on STDIN. Only some of them will send output to STDOUT. All tools which manipulate text (text filters) will utilize both STDIN and STDOUT.}}}
!! Redirection - moving input or output between a command and a file
We have new shell metacharacters to assist with the management of input and output:
* {{Monospaced{>}}} : Redirect output - Send a command's output to a file, overwriting existing contents
** {{Command{ users > userlist }}}
** {{Command{ who > loggedin }}}
* {{Monospaced{>>}}} : Redirect output - Send a command's output to a file, appending to existing data
** {{Command{ who >> loggedin }}}
** {{Command{ (date ; who) >> loggedin }}}
* {{Monospaced{ < }}} : Redirect input - Take a command's input from a file
** {{Command{ tr ' ' , < userlist }}}
* Disable output by redirecting it to {{File{/dev/null}}}, the unix garbage can
** {{Command{ make > /dev/null }}}
!! Standard Error (STDERR)
Some commands use a separate data stream, STDERR, for displaying any error or diagnostic output. Having this extra output on a separate stream allows us to handle it differently. We can send STDOUT to one destination and STDERR to another.
We can prefix our redirection symbols (''>'', ''>>'', or ''|'') with a ''2'' (the STDERR file descriptor) to send STDERR to a different destination.
For example, notice how the error message from the second command is discarded:
{{{
[root@shell cs307]# id username
id: username: no such user
[root@shell cs307]# id username 2> /dev/null
[root@shell cs307]# id merantn 2> /dev/null
uid=7289(merantn) gid=100(users) groups=100(users),307(cs307)
[root@shell cs307]# id merantn 2> /dev/null 1> /dev/null
}}}
The last command redirects both STDOUT and STDERR. We have no output at all.
!! Command Execution
* Chaining commands (Pipelines):
** Workflows can be completed as a pipeline of simple tools
** Glue multiple commands together to perform complex tasks out of simple tools
** Send STDOUT of one command as STDIN to another with the {{Monospaced{ ''|'' }}} (pipe) symbol
** The first command in a pipeline must be able to send output to STDOUT and second command must be able to read input from STDIN
** Examples:
*** {{Command{ who | sort | less }}}
*** {{Command{ who | wc -l }}}
*** {{Command{ last | cut -d ' ' -f 1 | sort | uniq }}}
*** ''This does not work! See yellow box above:'' {{Command{ ls * | rm }}}
**** File manipulation utilities like rm do not work with STDIN and STDOUT
* Send to STDOUT and save to a file with the {{Command{tee}}} command
** {{Command{ df | grep mapper | tee fs }}}
** {{Command{ df | tee fs | grep mapper }}}
*Sequenced commands: {{Command{ command1 ; command 2 }}}
** There's no direct relationship between these two commands.
** They do not share input or output. They're just running in sequential order on a single line.
** {{Command{ echo Today is `date` > Feb ; cal >> Feb }}}
* Grouped commands: {{Command{ (command1 ; command2) }}}
** {{Command{ (echo Today is `date` ; cal ) > month }}}
** Run the these two commands in a sub-shell, saving the output to {{File{month}}}
** A new shell instance is invoked, so any new settings or shell variables are not sent back to parent shell
*** Observe the current directory after running this command sequence: {{Command{ ( cd / ; ls ) ; pwd }}}
!! Chaining Commands with text filters:
We can now build flexible and customized solutions to solve wide range of problems.
The Linux filter tools are very useful for manipulating data
Filter definition: any command that takes input one line at a time from STDIN, manipulates the input, and sends the result to STDOUT
To most effectively solve a problem, you must know the available tools. Know the commands and be familiar with the options available.
When working with the filters to solve problems:
* Break the problem down into small parts
* Choose your tools that best align to those smaller parts
* Experiment
* Perfect and simplify your solution
!!! The Core Filters:
* {{Command{cat}}} - concatenate one or multiple files
** {{Monospaced{-n}}} option - numbered lines
** create text files by redirecting output to a file
* {{Command{head}}} - display lines from the beginning of a file
** {{Monospaced{-n}}} - display first //n// lines
* {{Command{tail}}} - display lines from the end of a file
** {{Monospaced{-n}}} - display last //n// lines
** {{Monospaced{+n}}} - Begin display at line //n//
** {{Monospaced{-f}}} - do not stop at eof, continue displaying new lines.
* {{Command{grep}}} - pattern matching within files or output: //pattern// //files(s)//
** {{Command{grep //pattern// file1 file2 file3}}}
*** Example: {{Command{grep dog //file(s)//}}}
** {{Command{//command1// | grep //pattern//}}}
*** {{Command{w | grep ^d}}}
** Anchors:
*** {{Monospaced{^}}} = line begins
*** {{Monospaced{$}}} = line ends
**Useful options:
*** {{Monospaced{-v}}} : Invert the match
*** {{Monospaced{-i}}} : Case insensitive
*** {{Monospaced{-l}}} : list only file names
*** {{Monospaced{-H}}} : list file name with matched pattern
**Examples:
*** Return lines from the output of {{Command{ls -l}}} that begin with the letter {{Monospaced}}}: {{Command{ls -l | grep ^d}}}
*** Return lines containing the string {{Monospaced{init}}} from files in the directory {{File{/etc/}}} which have names that start with {{Monospaced{rc}}}: {{Command{grep init /etc/rc*}}}
*** Copy those files from the above question to the {{File{scripts/}}} directory: {{Command{cp `grep -l init /etc/rc*` scripts/}}}
*** Display lines in {{File{/etc/printcap}}} which are not empty: {{Command{grep -v '^$' /etc/printcap}}}
**** The {{Monospaced{^$}}} together like this means the line begins and then immediately ends.
* {{Command{sort}}} - sort lines in the output of text files
**sort passwd file
**Options:
*** {{Monospaced{-n}}} : Numeric
*** {{Monospaced{-r}}} : Reverse
*** {{Monospaced{-k}}} : sort on field #
*** {{Monospaced{-t}}} : Specify delimiter (default whitespace)
** Examples:
*** {{Command{sort /etc/passwd}}}
*** {{Command{sort -t : -k 5 /etc/passwd}}}
*** {{Command{sort -n -t : -k 3 /etc/passwd}}}
* {{Command{uniq}}} - filter out repeated lines in the output of a file
**Must be sorted before showing unique values
**{{Monospaced{-c}}} : Count number of matches
* {{Command{wc}}} - word, line, character, and byte count
** {{Monospaced{-w}}} = word count
** {{Monospaced{-l}}} = line count
* {{Command{cut}}} - extract selected portions from each line of a file, either a range of characters or delimited columns
** Two main usage options:
*** By delimited columns:
**** {{Monospaced{-d}}} : Specifies the delimiter (defaults to tab)
**** {{Monospaced{-f}}} : Specifies the field(s) to display
*** Range of characters:
**** {{Monospaced{-c}}} : Extract character ranges
** Examples:
*** Extract field 2 through 4 from file data.txt, delimited by a semi-colon: {{Command{cut -d ';' -f 2-3 data.txt}}}
*** Extract characters 65 through end of line from the ~Fail2Ban log: {{Command{cut -c 65- fail2ban.log}}}
* {{Command{strings}}} - Search for strings in binary files
*Compare files
** {{Command{cmp}}} - compare two files
** {{Command{diff}}} - compare files line by line
** {{Command{comm}}} - select or reject lines common to two files
{{Note{''Note'': Abuse of the {{Command{cat}}} command, like demonstrated in [[Useless use of cat|https://en.wikipedia.org/wiki/Cat_(Unix)#Useless_use_of_cat]], is a sloppy practice that will cost points. Commands which accept filenames as arguments do not normally need the {{Command{cat}}} command to provide input via a pipeline.
Consider these two command examples:
* {{Command{grep pattern file}}}
* {{Command{cat file | grep pattern}}}
The {{Command{cat}}} command provides no value to the second example and should not be used. The first example is the proper way to accomplish this task.
}}}
! Assignment
!! Read:
* Chapter 15 in //Harley Hahn's Guide to Unix and Linux//
* Chapter 23, pages 633 & 634
** //Read the Special Files for ~Pseudo-Devices// section
!! Watch
* Linux Sysadmin Basics 04 -- Shell Features -- Pipes and Redirection - https://www.youtube.com/watch?v=-Z5tCri-QlI
!! Complete
* [[Lab 14|labs/lab14.pdf]] & [[Lab 15|labs/lab15.pdf]]
! Review
We'll spend the first part of the class reviewing previous labs to ensure we're all caught up
! Material
!! Read:
* Chapter 16 in //Harley Hahn's Guide to Unix and Linux//
** Focus mostly on {{Command{cat}}}, {{Command{head}}}, & {{Command{tail}}},
* Chapter 17:
** Start at the top page 410 with the {{Command{cut}}} filter
** Comparing files and {{Command{diff}}} is great to know, but we likely won't be using it now
* Chapter 18:
** Focus on the {{Command{wc}}} command starting on page 424
** The //How Unix Uses Tabs// section on 427-429 is good background info
** The rest of the commands in this chapter have very limited use and can be skipped. We'll only use {Command{wc}}} from Ch 18.
!! Watch:
* [[15 terminal commands that will boost your productivity|https://www.youtube.com/watch?v=tD8qzBmi-t0]]
** This video is a good command overview. There's more in here than we need now, but we'll be using all of these commands at some point this semester
** He moves pretty fast, so be prepared to pause to catch the commands or slow down the video speed
! Filters
!! Chapter 16-18 filters
* {{Command{cat}}} - concatenate one or multiple files
** {{Monospaced{-n}}} option - numbered lines
** create text files by redirecting output to a file
* {{Command{head}}} - display lines from the beginning of a file
** {{Monospaced{-n}}} - display first //n// lines
* {{Command{tail}}} - display lines from the end of a file
** {{Monospaced{-n}}} - display last //n// lines
** {{Monospaced{+n}}} - Begin display at line //n//
** {{Monospaced{-f}}} - do not stop at eof, continue displaying new lines.
* {{Command{wc}}} - word, line, character, and byte count
** {{Monospaced{-w}}} = word count
** {{Monospaced{-l}}} = line count
* {{Command{cut}}} - extract selected portions from each line of a file, either a range of characters or delimited columns
** Two main usage options:
*** By delimited columns:
**** {{Monospaced{-d}}} : Specifies the delimiter (defaults to tab)
**** {{Monospaced{-f}}} : Specifies the field(s) to display
*** Range of characters:
**** {{Monospaced{-c}}} : Extract character ranges
** Examples:
*** Extract field 2 through 4 from file data.txt, delimited by a semi-colon: {{Command{cut -d ';' -f 2-3 data.txt}}}
*** Extract characters 65 through end of line from the ~Fail2Ban log: {{Command{cut -c 65- fail2ban.log}}}
{{Note{''Note'': Abuse of the {{Command{cat}}} command, like demonstrated in [[Useless use of cat|https://en.wikipedia.org/wiki/Cat_(Unix)#Useless_use_of_cat]], is a sloppy practice that will cost points. Commands which accept filenames as arguments do not normally need the {{Command{cat}}} command to provide input via a pipeline.
Consider these two command examples:
* {{Command{grep pattern file}}}
* {{Command{cat file | grep pattern}}}
The {{Command{cat}}} command provides no value to the second example and should not be used. The first example is the proper way to accomplish this task.
}}}
!! Upcoming filters
* {{Command{grep}}} - pattern matching within files or output: //pattern// //files(s)//
** {{Command{grep //pattern// file1 file2 file3}}}
*** Example: {{Command{grep dog //file(s)//}}}
** {{Command{//command1// | grep //pattern//}}}
*** {{Command{w | grep ^d}}}
** Anchors:
*** {{Monospaced{^}}} = line begins
*** {{Monospaced{$}}} = line ends
**Useful options:
*** {{Monospaced{-v}}} : Invert the match
*** {{Monospaced{-i}}} : Case insensitive
*** {{Monospaced{-l}}} : list only file names
*** {{Monospaced{-H}}} : list file name with matched pattern
**Examples:
*** Return lines from the output of {{Command{ls -l}}} that begin with the letter {{Monospaced}}}: {{Command{ls -l | grep ^d}}}
*** Return lines containing the string {{Monospaced{init}}} from files in the directory {{File{/etc/}}} which have names that start with {{Monospaced{rc}}}: {{Command{grep init /etc/rc*}}}
*** Copy those files from the above question to the {{File{scripts/}}} directory: {{Command{cp `grep -l init /etc/rc*` scripts/}}}
*** Display lines in {{File{/etc/printcap}}} which are not empty: {{Command{grep -v '^$' /etc/printcap}}}
**** The {{Monospaced{^$}}} together like this means the line begins and then immediately ends.
* {{Command{sort}}} - sort lines in the output of text files
**sort passwd file
**Options:
*** {{Monospaced{-n}}} : Numeric
*** {{Monospaced{-r}}} : Reverse
*** {{Monospaced{-k}}} : sort on field #
*** {{Monospaced{-t}}} : Specify delimiter (default whitespace)
** Examples:
*** {{Command{sort /etc/passwd}}}
*** {{Command{sort -t : -k 5 /etc/passwd}}}
*** {{Command{sort -n -t : -k 3 /etc/passwd}}}
* {{Command{uniq}}} - filter out repeated lines in the output of a file
**Must be sorted before showing unique values
**{{Monospaced{-c}}} : Count number of matches
* {{Command{strings}}} - Search for strings in binary files
*Compare files
** {{Command{cmp}}} - compare two files
** {{Command{diff}}} - compare files line by line
** {{Command{comm}}} - select or reject lines common to two files
! Assignment
!! Read:
* Chapter 16 in //Harley Hahn's Guide to Unix and Linux//
** Focus mostly on {{Command{cat}}}, {{Command{head}}}, & {{Command{tail}}},
* Chapter 17:
** Start at the top page 410 with the {{Command{cut}}} filter
** Comparing files and {{Command{diff}}} is great to know, but we likely won't be using it now
* Chapter 18:
** Focus on the {{Command{wc}}} command starting on page 424
** The //How Unix Uses Tabs// section on 427-429 is good background info
** The rest of the commands in this chapter have very limited use and can be skipped. We'll only use {Command{wc}}} from Ch 18.
!! Watch:
* [[15 terminal commands that will boost your productivity|https://www.youtube.com/watch?v=tD8qzBmi-t0]]
** This video is a good command overview. There's more in here than we need now, but we'll be using all of these commands at some point this semester
** He moves pretty fast, so be prepared to pause to catch the commands or slow down the video speed
!! Complete
* [[Lab 16|labs/lab16.pdf]] & [[Lab 17|labs/lab17.pdf]]
! Material
!! Read:
* Chapter 19 in //Harley Hahn's Guide to Unix and Linux//
** Stop at {{Command{tr}}} on page 482
** Focus mostly on {{Command{grep}}}, {{Command{sort}}}, {{Command{uniq}}}, & {{Command{strings}}}
! Filters, continued
!! This chapter's filters:
* {{Command{grep}}} - pattern matching within files or output: //pattern// //files(s)//
** {{Command{grep //pattern// file1 file2 file3}}}
*** Example: {{Command{grep dog //file(s)//}}}
** {{Command{//command1// | grep //pattern//}}}
*** {{Command{w | grep ^d}}}
** Anchors:
*** {{Monospaced{^}}} = line begins
*** {{Monospaced{$}}} = line ends
**Useful options:
*** {{Monospaced{-v}}} : Invert the match
*** {{Monospaced{-i}}} : Case insensitive
*** {{Monospaced{-l}}} : list only file names
*** {{Monospaced{-H}}} : list file name with matched pattern
**Examples:
*** Return lines from the output of {{Command{ls -l}}} that begin with the letter {{Monospaced}}}: {{Command{ls -l | grep ^d}}}
*** Return lines containing the string {{Monospaced{init}}} from files in the directory {{File{/etc/}}} which have names that start with {{Monospaced{rc}}}: {{Command{grep init /etc/rc*}}}
*** Copy those files from the above question to the {{File{scripts/}}} directory: {{Command{cp `grep -l init /etc/rc*` scripts/}}}
*** Display lines in {{File{/etc/printcap}}} which are not empty: {{Command{grep -v '^$' /etc/printcap}}}
**** The {{Monospaced{^$}}} together like this means the line begins and then immediately ends.
* {{Command{sort}}} - sort lines in the output of text files
**sort passwd file
**Options:
*** {{Monospaced{-n}}} : Numeric
*** {{Monospaced{-r}}} : Reverse
*** {{Monospaced{-k}}} : sort on field #
*** {{Monospaced{-t}}} : Specify delimiter (default whitespace)
** Examples:
*** {{Command{sort /etc/passwd}}}
*** {{Command{sort -t : -k 5 /etc/passwd}}}
*** {{Command{sort -n -t : -k 3 /etc/passwd}}}
* {{Command{uniq}}} - filter out repeated lines in the output of a file
**Must be sorted before showing unique values
**{{Monospaced{-c}}} : Count number of matches
!! Pattern Matching with {{Command{grep}}}:
The {{Command{grep}}} filter is one of the most useful; I use it almost daily. It's worth spending a little more time working with and ensuring we're all on the same page with our terminology. ''From here on, I'm going to start being a little more strict with wording, so be thorough with your explanations.''
!!! {{Command{grep}}} - Display all lines from a file or stream containing a specified pattern
* Usage: {{Monospaced{grep //pattern// [file1] [file2] [file3] [file//n//]}}}
* Search for //pattern// in each of the specified files
* Useful options:
** {{Monospaced{''-v''}}} : Invert the match; display lines which ''do not'' contain the specified pettern
** {{Monospaced{''-i''}}} : Case insensitive search
** {{Monospaced{''-l''}}} : list only names of files which contain a match
** {{Monospaced{''-H''}}} : include file name with matched pattern
* Examples:
** {{Command{grep dog data.txt}}} - Display all lines from the file ''data.txt'' containing the string ''dog''
** {{Command{grep ssh /etc/*.conf}}} - Display all lines from files ending with ''.conf'' within the directory ''/etc/'' containing the string ''ssh''
{{Note{
!!! ''Important Notes:''
!!!! 1) The following all have distinct meanings. Be sure to use them properly.
* ''Line'': The entire line
* ''String'': A sequence of characters
* ''Word'': A sequence of characters with whitespace or punctuation on either side or at the beginning or end of a line.
* ''Characters'': Individual characters, not necessarily together
!!!! 2) By default, the grep filter will display all lines which match a particular pattern or string. Be specific when describing its actions in the labs.
For example, if you are asked to describe what the following command is doing:
<<<
{{Command{grep ab data.txt}}}
<<<
and your response is something vague and generic like "//finds ab in the file//" you will not receive full credit. Be ''through and specific''! What happens when a match is found? Which file is being examined? Where is the output going? I've allowed vague descriptions in previous labs, but that must end as our familiarity with these tools is increasing.
A proper response will cover all points:
Display to ''STDOUT'' all ''lines'' containing the string ''ab'' from the file ''data.txt''
!!!! 3) If multiple commands are chained together, don't just itemize what each command in the pipeline is doing. Be sure to also describe its final outcome. We must appreciate the big picture as well.
}}}
!!! Anchors:
When trying to match a pattern in a tool like {{Command{grep}}}, anchors allow us to specify where on the string a pattern must occur. This is useful if we're trying to match something which appears at either the beginning or end of a line instead of somewhere in the middle.
Anchors can be utilized with two anchor metacharacters:
* ^ = begins with
* $ = end with
* Examples:
** {{Command{grep '^string' data.txt}}} - Display lines from the file ''data.txt'' beginning with ''string''
** {{Command{grep 'string$' data.txt}}} - Display lines from the file ''data.txt'' which end with ''string''
Chapter 20, pp 502-504 (//Matching Lines and Words//) contains more information on anchors.
! Assignment
!! Read:
* Chapter 19 in //Harley Hahn's Guide to Unix and Linux//
** Stop at {{Command{tr}}} on page 482
** Focus mostly on {{Command{grep}}}, {{Command{sort}}}, {{Command{uniq}}}, & {{Command{strings}}}
!! Complete:
* Labs: [[Lab 18|labs/lab18.pdf]] & [[Lab 19|labs/lab19.pdf]]
! Material
!! Read:
* Chapter 19 in //Harley Hahn's Guide to Unix and Linux//
** Start at {{Command{tr}}} on page 482
!! Watch:
* {{Command{tr}}}:
** How to Use {{Command{tr}}}, {{Command{sed}}}, and {{Command{aspell}}}: Linux Terminal 201 - https://www.youtube.com/watch?v=F7Brrn-L1Zg
** Mostly for {{Command{tr}}}, but there's some talk about {{Command{sed}}} too
** Hak5 has a lot of great content. Check out their other videos.
* {{Command{awk}}}:
** Learning awk - https://www.youtube.com/watch?v=9YOZmI-zWok
** This video goes into advanced usage at the 11:30 mark that won't be covering in this class. You can stop at that point if you'd like.
* {{Command{sed}}}:
** SED Tutorial Basic Substitution - https://www.youtube.com/watch?v=32waL1Z9XK0&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=1
** SED Substitute Beginning and End of Line: https://www.youtube.com/watch?v=8T5azKqYAjc&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=2
** SED Remove Lines When Match is Found: https://www.youtube.com/watch?v=37r5Ykdnlkk&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=13
** The entire sed series has great content, but those three are the highlights
! More complex filters
The {{Command{tr}}}, {{Command{awk}}}, and {{Command{sed}}} commands are a little more complex than the others we've introduced, but all three are important tools to have in your toolbox. {{Command{awk}}} is easier to work with than {{Command{cut}}} for extracting columns of text. {{Command{sed}}} is especially useful for search and replace operations and extracting particular rows of text from a file.
* {{Command{tr}}} - Translate characters
**Works only on stdin, does not alter the file, only the data stream
**Two arguments for translating characters (set1/from) (set2/to)
**Input characters in ''//set1//'' are mapped to corresponding characters in ''//set2//''.
**If the length of the two sets are unequal:
***''//set1//'' larger then ''//set2//'': ''//set2//'' is extended to the length of set1 by repeating ''//set2//'''s last character as necessary.
***''//set2//'' larger then ''//set1//'': Excess characters in ''//set2//'' are ignored.
**Options:
*** {{Monospaced{-d}}} : delete (one argument for which characters to delete)
*** {{Monospaced{-s}}} : Squeeze multiple consecutive occurrences of a character down into a single instance.
** Character classes:
*** Another way to identify groups of characters
*** Page 260 & 261 in //The Linux Command Line//
*** {{Monospaced{[:digit:]}}}
*** {{Monospaced{ [:alpha:] [:lower:] [:upper:] }}}
*** {{Monospaced{[:space:] [:blank:]}}}
**Examples:
*** {{Command{tr '[:upper:]' '[:lower:]' < /etc/printcap}}}
*** {{Command{tr '[:upper:]' '*' < /etc/printcap}}}
*** {{Command{tr -s '[:upper:]' '*' < /etc/printcap}}}
** Special characters
*** On the unix command line, {{Monospaced{''\t''}}} will represent a tab and {{Monospaced{''\n''}}} will represent a newline. {{Command{tr}}} supports using these for substitutions.
{{Warning{''Important note:'' Most students have trouble with the {{Command{tr}}} command and interpret its actions incorrectly. {{Command{tr}}} stands for //translate//, and as such it translates ''characters'' individually. It does ''NOT'' translate strings. A string is a sequential list of characters in order. There is a big difference between a ''character'' and a ''string''. For comparison, a //character// would be a single letter where a //string// is a full word.
{{Command{tr}}} will individually translate the characters from the first argument into the characters in the second argument according to their placement. The first character in argument 1 will be translated into the first character in argument 2. The translation will proceed for each character in the first argument to the corresponding position in the second argument.
{{Command{cat data.txt | tr one two}}} does not convert the string //one// to the string //two// in the output of {{File{data.txt}}}. It converts each ''o'' to ''t'', each ''n'' to ''w'', and each ''e'' to ''o''. Each of those characters in the output of {{File{data.txt}}} is changed individually.
When completing labs involving {{Command{tr}}}, it is important that your responses indicate these translations are happening //character by character//. Additionally, the translation does not occur //in the file// {{File{data.txt}}}. Our source files are not modified by the filters. It is important to indicate the translation is occurring in the //output// of the file {{File{data.txt}}}.
''➜'' Providing a response which is not clear on these important points will be considered incorrect.}}}
!! {{Command{''sed''}}} & {{Command{''awk''}}}
I like using {{Command{''awk''}}} instead of {{Command{''cut''}}}. Everything {{Command{''cut''}}} can do {{Command{''awk''}}} can do better. Often our delimiters are variable lengths of whitespace, such as several spaces or several tabs. {{Command{''cut''}}} can only delimit on a single character, but {{Command{''awk''}}}'s default delimiter is whitespace, regardless how long it is. {{Command{''awk''}}} can also use multiple characters as a delimiter at the same time.
There's an [[Oreilly book|https://www.oreilly.com/library/view/sed-awk/1565922255/]] for just these two commands. They're pretty powerful, but we're only going to scratch the surface. We'll mostly work with {{Command{''awk''}}} but {{Command{''sed''}}} is good to know too. Both come in very handy.
* {{Command{awk}}}
** {{Command{awk}}} is a fully functional programming language written for processing text and numbers.
** {{Command{tr}}} works byte by byte (1 character at a time)
** {{Command{grep}}} works line by line
** {{Command{awk}}} works field by field
** Terminology:
*** Record = line of input
*** Field = a column of data, separated by a delimiter
** basic usage: {{Command{awk [-F//delim//] '{ action ; action ; action }' }}}
*** default action is to print the entire record
*** {{Monospaced{ ''-F'' }}} = specify alternate field separator (default is whitespace)
*** Multiple delimiters can be used. For example, the option {{Monospaced{ ''-F'[-:]' '' }}} will set the delimiter to be either a colon or a dash.
*** ''Note:'' {{Command{cut}}} uses a single character for a delimiter where {{Command{awk}}}'s default is any amount of whitespace. This is especially handy if a sequence of spaces or tabs is used between columns, such as in the output of the {{Command{w}}} command.
** advanced usage: {{Command{ awk [-F//delim//] [ -v var=value ] '//pattern// { action ; action ; action }' }}}
*** //pattern// is an optional way to specify which lines to operate on
*** {{Monospaced{ ''-v'' }}} = define a variable and its value to be used within awk. ex: {{Monospaced{ ''-v start=10'' }}}
** Useful awk variables:
*** {{Monospaced{ ''$0'' }}} - The entire line of text
*** {{Monospaced{ ''$//n//'' }}} - The //n//^^th^^ data field of the record
*** {{Monospaced{ ''$0'' }}} - Entire line
*** {{Monospaced{ ''NR'' }}} - record number
** Patterns can be (advanced use only, I will not give problems in labs or tests that require this):
*** Relational expressions ( {{Monospaced{ ''<=, <, >, >=, ==, !='' }}} )
**** ex: {{Monospaced{ ''$1 == $2'' }}}
*** Regular expressions /regex/
**** Must be enclosed in {{Monospaced{ ''/ /'' }}}
**** When specified, the regex must match somewhere on the line. example: {{Monospaced{ ''/[0-9]+/'' }}}
**** Or use a pattern matching expression ( {{Monospaced{ '' ~, !~'' }}} ) to match regex to a specific field. example: {{Monospaced{ ''$1 ~ /^string/'' }}}
** Examples:
*** Show only the username and tty from the output of the {{Command{w}}} command: {{Command{w | awk '{print $1 " " $2}' }}}
**** Same output, but skip the first two header lines: {{Command{w | awk ' NR > 2 {print $1 " " $2}' }}}
*** Set the delimiter to be the string {{Monospaced{ ''", "''}}} (comma then space), then invert the first and last names: {{Command{awk -F", " '{print $2, $1}' names }}}
* {{Command{sed}}}: Stream editior //commands// //file(s)//
**Works mainly on streams, but can also be used to modify files in place when used with the {{Monospaced{ -i }}} option.
*** Be sure you are clear about this in your labs. A response that indicates a change or deletion is occurring in the file will not be correct. By default, changes are happening to the output of the file.
**We use {{Command{sed}}} to change the text in a stream.
**For each line in the //file//, check to see if it is addressed. If so, perform //command//
**[address1[,address2]] command [options]
***Addresses can be line numbers: start[,stop]
***simple patterns: {{Monospaced{ /pattern/ }}}
***The pattern can contain our ^ and $ anchors
***or regular expressions: {{Monospaced{ /regex/ }}}
***Defaults to all lines if none are addressed
**Most used sed commands
*** {{Monospaced{s}}} - substitute - {{Monospaced{s/find/replace/flags}}}
**** flags:
**** {{Monospaced{g}}} - all instances on the line
**** {{Monospaced{p}}} - print lines containing a substitution
*** {{Monospaced{d}}} - delete line
*** {{Monospaced{p}}} - print line
*** {{Monospaced{y}}} - translate characters on the line (similar to {{Command{tr}}} command)
**Options:
*** {{Monospaced{-n}}} : suppress normal behavior and only show lines addressed and given {{Monospaced{p}}} command.
**sed examples:
*** {{Command{sed 7p file1}}} - print line 7 twice (notice absence of {{Monospaced{-n}}} option)
*** {{Command{sed '7d' file1}}} - delete line 7 from the output
*** {{Command{sed '/pattern/d' file1}}} - delete all lines containing //pattern// from the output
****Pattern can contain ^ and $ anchors and [sets]
****[sets] examples: [abc] [aeiou] [~A-Z] [a-z] [A-z] [0-9]
*** {{Command{sed -n '1,6p' file1}}} - only print lines 1 through 6 (notice the inclusion of the {{Monospaced{-n}}} option)
*** {{Command{sed 's/Sam/Bob/' file1}}} - All lines with Sam changed to Bob (just once)
*** {{Command{sed 's/Sam/Bob/g' file1}}} - All lines with Sam changed to Bob (all matches on the line)
*** {{Command{sed 's/Sam/Bob/gp' file1}}} - All lines with Sam changed to Bob (all matches on the line). Notice the lack of the {{Monospaced{-n}}} option.
*** {{Command{sed -n 's/Sam/Bob/gp' file1}}} - All lines with Sam changed to Bob (all matches), only printing lines where the substitution occurred
*** For addressing lines, {{Monospaced{$}}} = last line in the output
{{Note{''Note:'' Always put your awk & sed commands (the first argument), within single quotes, for example: {{Command{sed -n '4,6p' file1.txt}}} }}}
! Assignment
!! Read:
* Chapter 19 in //Harley Hahn's Guide to Unix and Linux//
** Start at {{Command{tr}}} on page 482
!! Watch:
* {{Command{tr}}}:
** How to Use {{Command{tr}}}, {{Command{sed}}}, and {{Command{aspell}}}: Linux Terminal 201 - https://www.youtube.com/watch?v=F7Brrn-L1Zg
** Mostly for {{Command{tr}}}, but there's some talk about {{Command{sed}}} too
** Hak5 has a lot of great content. Check out their other videos.
* {{Command{awk}}}:
** Learning awk - https://www.youtube.com/watch?v=9YOZmI-zWok
** This video goes into advanced usage at the 11:30 mark that won't be covering in this class. You can stop at that point if you'd like.
* {{Command{sed}}}:
** SED Tutorial Basic Substitution - https://www.youtube.com/watch?v=32waL1Z9XK0&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=1
** SED Substitute Beginning and End of Line: https://www.youtube.com/watch?v=8T5azKqYAjc&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=2
** SED Remove Lines When Match is Found: https://www.youtube.com/watch?v=37r5Ykdnlkk&list=PLcUid3OP_4OW-rwv_mBHzx9MmE5TxvvcQ&index=13
** The entire sed series has great content, but those three are the highlights
!! Complete:
* Labs: [[Lab 20|labs/lab20.pdf]], [[Lab 21|labs/lab21.pdf]] & [[Lab 22|labs/lab22.pdf]]
! Review:
!! I/O Practice
Lab 23 is a practice lab for I/O and moving output from one command to another. It will leverage material from the last two weeks to solve a real-world problem and is a good example of using these tools and concepts. This lab will introduce the {{Command{openssl}}} command with a couple examples and then ask you to use it to return useful data.
!! Complete:
* [[Lab 23|labs/lab23.pdf]]
! Material:
!! Read:
* Chapter 13 in //Harley Hahn's Guide to Unix and Linux//
** Pages 277-284
** Stop at //Commands that are Build into the Shell//
!! Watch:
* Linux shell quotes: https://www.youtube.com/watch?v=1Ukw0IjGKsI
! Escaping & Quoting:
!! Quoting - ' " \
Some special characters, such as the space and most symbols, have a special meaning to the shell. Occasionally we need to use those special characters literally without allowing the shell to interpret their special meanings.
Quoting allows us to protecting these special characters from the shell. It is necessary in order to use a metacharacter literally, to disable its special shell meaning.
For example, consider the scenario where you need to display the contents of a file which contains a space in the name. The space has a special meaning to the shell; it is our argument separator.
If my file is named {{File{my notes.txt}}}, and I try to execute the command {{Command{cat my notes.txt}}} to display it, the space in the file name will cause cat to try to display the file {{File{my}}} and the file {{File{notes.txt}}}, neither of which actually exist.
I need to protect that special symbol, the space, from the shell to ensure the cat command get it. There are three ways I can do so:
* {{Command{cat "my notes.txt"}}}
* {{Command{cat 'my notes.txt'}}}
* {{Command{cat my\ notes.txt}}}
Each of the options work a little differently. Knowing these differences allows you to choose the best method for the task.
!!! Three ways to quote:
* Backslash ({{Monospaced{\}}}) - Changes the interpretation of the character that follows
** {{Monospaced{\}}} is the escape character, which will disable special meaning of a shell special character.
** Converts special characters into literal characters and literal characters into special characters
** n vs \n
*** The {{Monospaced{\}}} will //enable// the special meaning of a regular character.
*** Newline - {{Monospaced{\n}}}
*** Tab - {{Monospaced{\t}}}
** {{Command{printf "Home is %s\n" $HOME}}}
** {{Monospaced{\}}} followed by return - suppress the special meaning of the return key
* Double Quote (weak) - Will remove the special meaning of //some// metacharacters
** {{Monospaced{"}}} quoting will still evaluate variable, command, and history substitution.
* Single Quote (strong) - Will remove the special meaning of //most// metacharacters
** {{Monospaced{'}}} is stronger then {{Monospaced{"}}}, which means it will protect more metacharacters from the shell
** {{Monospaced{'}}} quoting will only evaluate history substitution in //some// shells. The single quote will not evaluate history substitution in {{Command{bash}}}
* You can alternate quotes to include the other type: {{Command{echo "Today's date is `date`"}}}
! Assignment:
!! Read:
* Chapter 13 in //Harley Hahn's Guide to Unix and Linux//
** Pages 277-284
** Stop at //Commands that are Build into the Shell//
!! Watch:
* Linux shell quotes: https://www.youtube.com/watch?v=1Ukw0IjGKsI
!! Complete:
* Labs: [[Lab 23|labs/lab23.pdf]] & [[Lab 24|labs/lab24.pdf]]
! Material
!! Read:
* Chapter 26 in //Harley Hahn's Guide to Unix and Linux//
!! Watch:
* [[Linux Terminal 101: Controlling Processes|https://www.youtube.com/watch?v=XUhGdORXL54]]
** Use a command like {{Command{less}}} or {{Command{tail -f}}} to test her examples. We do not have {{Command{gedit}}} available.
* [[Linux Terminal 101: How to View Processes|https://www.youtube.com/watch?v=Udr-qE0NEO0]]
! Process Management & Job Control
We're going to take a break from filters and managing text for a moment to review some system utilities and concepts. Our next material contains information on process management and job control. This will become especially useful once we start shell scripting. This material will assist you with running multiple simultaneous tasks on the system and monitor system resources to ensure your scripts are not impacting performance.
''Processes'' and ''Jobs'' have simple, fundamental differences:
- Processes refer to all tasks currently running on the Linux system. Every running task is considered a process and has a unique process ID.
- Jobs are relative to your current login session. They refer to current tasks you are running in that shell instance that may be running in the background, running in the foreground, or paused. This presents an easy way to run multiple tasks at the same time from the same shell session or easily move between two tasks (eg: a text editor and a man page)
These are my notes from the last time I taught this class as a lecture. Be sure to also read the chapter.
!! Processes
Everything on the system is represented by either a file or a process - something that physically exists or something that's running.
A process is a program that is executing
Files provide us with data, processes make things happen
The kernel manages processes - all processes are assigned a Process ID number (PID)
The kernel also maintains a process table to keep track of everything, indexed by that PID.
Processes are a mix of system and user processes. In the process list, kernel process are listed within [ ]
The kernel contains a scheduler to manage the workload and share system resources
The scheduler chooses a waiting process and grants it a short slice of time to run along with any needed resources (processor, memory, I/O, other devices, etc)
If the process is not completed within it's time slice, it goes back into the scheduling list and waits for additional processing time
time slice = short interval a process is allowed to run for.
Every process is created (forked) from another process
Killing the parent process will (in most cases) kill the child processes
When a process dies or completes, it's resources are reallocated
init/systemd process, PID 1 - parent to all processes on the system
created early in the boot procedure to set up the kernel and complete booting functions
!! ps command
*ps - process status
*will show useful process information
*BSD options versus UNIX options
* These are some BSD options (also available in Linux)
**{{Command{ps}}} - Show processes for your current login session
**{{Command{ps -a}}} - Show all user processes
**{{Command{ps -u}}} - Display additional process information
***%CPU - percentage CPU usage
***%MEM - percentage memory usage
***VSZ - virtual size in Kbytes
***RSS - resident set size
***TT - control terminal name (tty//x////x//)
***STAT - symbolic process state
***TIME - accumulated CPU time, user + system
**{{Command{ps -x}}} - Display system processes
**{{Command{ps -aux}}} - Show extended information on all processes - This is often the most useful way to use the command.
**{{Command{ps -U //username//}}} - Display processes associated with //username//
**{{Command{ps -P //PID//}}} - Display processes associated with process ID //PID//
*top - display and update information about the top cpu processes
**THR -
**PRI - current priority of the process
**NICE - nice amount (in the range -20 to 20)
**SIZE - total size of the process (text, data, and stack) (in K)
**RES - current amount of resident memory (in K)
**STATE - current process state (START, RUN, SLEEP, STOP, ZOMB, WAIT, LOCK)
**C - processor number on which the process is executing
**TIME - number of system and user cpu seconds that the process has used
**WCPU - weighted cpu percentage
!! Killing Processes
*kill [-signal] //pid//
* Common Signals:
| !Signal Number | !Signal Abbreviation | !Description |
| 1 | HUP |Hangup (restart process, reload config)|
| 2 | INT |Interrupt (~CTRL-C)|
| 3 | QUIT |Quit|
| 9 | KILL |Immediate kill. Not catchable or ignorable.|
| 15 | TERM |Request to gracefully terminate (default)|
SIGINFO = ~CTRL-T (~FreeBSD Only)
* Killing large groups of processes
**{{Command{pkill}}} & {{Command{pgrep}}} - look up or signal processes based on name and other attributes
**{{Command{killall}}} - kill processes by name
*** This may not come installed by default in all Linux distributions.
[>img[img/jobs.png]]
!! Jobs & job control
*Jobs - a command or set of commands entered in one command line.
*jobs are related to the user's session and are not global.
*STDIN is locked while a job is running in the foreground - it is only available to the current job until it completes.
*running background jobs allow the user to access these resources and have control of the shell.
*background jobs will still send their output to the screen and must be brought back to the foreground if they request input from the user
*a job may have one of three states - foreground, background, and stopped.
* append ''&'' to the command string to run it directly to the background
*~CTRL-Z - suspend a running foreground process
*Related commands:
** {{Command{jobs}}}
** {{Command{fg}}}
** {{Command{bg}}}
** {{Command{kill -STOP %//id//}}}
* Manipulate jobs with ''%'' and the job number
** Examples: {{Command{fg %1}}} - resume the first background job in the foreground
** {{Command{bg %2}}} - resume the second job in the background
*currency flags: ''+'' and ''-''
** ''+'' most recently accessed job, default job if no arguments are specified.
** ''-'' second most recently accessed job, default job when ''+'' flagged job completes.
!! Two additional recommended videos:
* Kill command video: https://www.youtube.com/watch?v=fT-h45L9RAY
* Difference between processes and jobs: https://www.youtube.com/watch?v=eqtiw8S8GZw
! Assignment
!! Read:
* Chapter 26 in //Harley Hahn's Guide to Unix and Linux//
!! Watch:
* [[Linux Terminal 101: Controlling Processes|https://www.youtube.com/watch?v=XUhGdORXL54]]
** Use a command like {{Command{less}}} or {{Command{tail -f}}} to test her examples. We do not have {{Command{gedit}}} available.
* [[Linux Terminal 101: How to View Processes|https://www.youtube.com/watch?v=Udr-qE0NEO0]]
!! Complete:
* [[Lab 25|labs/lab25.pdf]]
! Material:
!! Read:
* Chapter 20 in //Harley Hahn's Guide to Unix and Linux//
! Regular Expressions
This material is a little more difficult to understand than most of what we'll be working on. Make use of Discord if you're running into trouble. We can also spin up a Zoom session if anyone would like to chat.
If anyone would like to dive deeper into this topic, I recommend [[Mastering Regular Expressions|https://www.oreilly.com/library/view/mastering-regular-expressions/0596528124/]]. It's an excellent technical book.
! Regular Expression Intro
* What is a regular expression?
** Compact way of specifying a pattern of characters
** text is evaluated against the pattern to determine if there is a match.
*** We can then perform actions based on that test
** We can use a regular expression to examine the contents of an entire file, such as with {{Command{grep}}}
** Or we can examine just a string (or variable), such as with input validation
* What are they used for?
** pattern matching - instead of searching for a simple word, search for more complex patterns -
*** Similar to how file globbing works. Only here, we're examining the //content// of the files and using the metacharacters a little differently
** Complex substitutions (search & replace)
*** Helpful in {{Command{vi}}} or a Windows text editor such as notepad++
** Input verification
*** Make sure the user is providing an appropriate input in a script or program. For example, if we prompt for an IP address, ensure what's provided is a valid IP address.
** Substring extractions
*** Extract a portion of a string to do something with that particular component.
*** For example, save to a variable for later use or save to a database
* How are they used?
** {{Command{grep}}} - basic regular expressions
** {{Command{egrep}}} or {{Command{grep -E}}} - extended regular expressions
** {{Command{sed}}}
** {{Command{vi}}}
** {{Command{python}}}
** any other programming language
What to match: a combination of ''atoms'' and ''operators''
''atom'' = something we're trying to match
''operator'' = how we're trying to match it
''Atoms'' - Any regular character, or:
| !Symbol | !Meaning | !Example | !Escape | !Not supported by |
| {{Monospaced{'' [ ] ''}}} |Character groups (match any one character listed) | [a-c0-3] | | |
|~|Characters may be specified singly or in ranges|~|~|~|
| {{Monospaced{'' [^ ] ''}}} |Negated character group (match any one character not listed| [^a-c0-3] | | |
| {{Monospaced{'' . ''}}} |Any single character| | | |
''Operators'' - Modify the atoms
These operators act as quantifiers, specifying the number of times an atom is matched.
| !Symbol | !Meaning | !Escape | !Not supported by |
| {{Monospaced{'' ? ''}}} |Optional item. Match 0 or 1. | | sed |
| {{Monospaced{'' * ''}}} |Repetition: 0 or more| | |
| {{Monospaced{'' + ''}}} |Repetition: 1 or more. | | sed |
| {{Monospaced{'' { } ''}}} |Repetition: Defined range of matches {//min//,//max//} or {//min//,} or {//exactly//}| * | |
| !Symbol | !Meaning | !Escape | !Not supported by |
| {{Monospaced{'' ( ) ''}}} |Grouping - next operator applies to whole group| | |
|~|Alternation (match any one of the sub-expressions)| | |
| {{Monospaced{'' {{{|}}} ''}}} |Or. Match either expression it separates. Use with ( )| | |
Grouping with the ''( )'' allow us to apply an operator to a group of atoms. For example, to make the entire string ''abcde'' optional: ''(abcde)?''. The ''?'' will apply to the entire sequence of characters within the ''( )''.
{{Note{''Note:'' We use file globbing to identify groups of files and regular expressions to identify groups of characters. File globbing is for file //names// and regular expressions are used for the file's //contents// or any other strings of characters. }}}
{{Warning{''Warning:'' Regular expressions use many of the same metacharacters as file globbing, but they work differently here. For example, if we want to list files which begin with the letter a, I would use the command {{Command{ls a*}}}. But with regular expressions, if I want to find a string that begins with an a, I need to use the regular expression {{Monospaced{ ''^a.*'' }}}. In file globbing, the {{Monospaced{'' * ''}}} stands alone. In regular expressions it is a modifier and changes the behavior of what comes before it. With regular expressions, the {{Monospaced{'' . ''}}} is used to specify any single character and the {{Monospaced{'' * ''}}} modifies it to match 0 or more occurrences.}}}
''Anchors'' can also be used to specify where our match must occur:
| !Symbol | !Meaning |
| ^ |Start of line|
| $ |End of line|
| \< |Beginning of word|
| \> |End of word|
Typically, when we are searching for a pattern, we are searching for a sub-string (a smaller string within a larger series of characters). For example, if I want to display lines which contain //only// numbers, the command {{Command{egrep '[1-9]+' data.txt}}} will return the output:
12345
a1234
b1234c
But I want lines which contain //only// numbers. I don't want to display the lines which also contain a letter. The solution to prevent other characters from sneaking into your output is to use the anchors to ensure your regular expression is ''//completely matched//''. This command will anchor the numbers to the beginning and end of the line so no other characters can be matched: {{Command{egrep '^[1-9]+$' data.txt}}}
[[Regular expression metacharacters]]
[[ASCII Chart|handouts/ascii-chart.gif]]
Regular expressions and file globbing have common metacharacters that have different meanings in the two contexts. ''Be sure you know how the metacharacters differ.''
!! Examples
!!!! Match:
* grey with either spelling - {{Monospaced{'' gr[ea]y ''}}}
* color with American or British spelling - {{Monospaced{'' colou?r ''}}}
* variations of third street (3rd street or third street) - {{Monospaced{'' (3|thi)rd street''}}}
* The month June either full or abbreviated - {{Monospaced{'' June? ''}}}
* find words with 5 or more vowels in a row - {{Command{'' egrep '[aeiou]{5}' /usr/share/dict/words ''}}}
* Find words in the unix dictionary file that begin with book and end with y - {{Command{ grep '^book.*y$' /usr/share/dict/words }}} - Don't forget the anchors!
* Find words that are 4 characters beginning with a b and ending with a k - {{Command{ grep '^b..k$' /usr/share/dict/words }}}
* Find words in the dictionary file that begin with or end with the string book - {{Command{ egrep '(^book|book$)' /usr/share/dict/words }}}
* Match Kunsela ~C-Wing B&W printer queue names - {{Command{ grep '^c...lpr' /opt/pub/cs307/data/filter_examples/printcap | cut -d '|' -f 1}}}
* Extract the mail sender and subject for the last 4 emails received - {{Command{egrep "^(From|Subject): " /var/mail/$USER | tail -n 8}}}
!!!! Input verification:
Completely match -
* a valid campus username - {{Monospaced{'' [a-z]{1,8}([0-9]{1,2})? ''}}} - 1 to 8 lowercase letters optionally followed by 1 or 2 numbers.
* a phone number - {{Monospaced{'' '^[0-9]{3}-[0-9]{3}-[0-9]{4}$' ''}}}
* time (12hr clock) - {{Monospaced{'' '^(1-9|1[0-2]):[0-5][0-9] [ap]m$' ''}}}
** What's the error with this one?
* a Dollar amount
What is the difference between [ab]* and (a*|b*)
!!! More complex examples:
!!!! Search the ssh configuration files for all configuration directives that are enabled with a yes:
Read this from bottom to top
{{{
egrep '^[^#]+ yes' /etc/ssh/ssh{,d}_config
^ ^ ^^--- ----
| | || ^ ^--- Match both ssh_config and sshd_config
| | || |--------------------- Followed by the string yes
| | ||----------------------- There must be a space between the configuration item and its value
| | |------------------------ The + modifies the [^#] to allow for any length of characters here.
| |-------------------------- Followed by any character which is not a #. We don't want comments.
|----------------------------- The line begins
}}}
This part is the regular expression that searches for the text: {{Monospaced{'' ^[^#]+ yes ''}}}
This part is the file globbing pattern that identifies the files to search: {{Monospaced{''/etc/ssh/ssh{,d}_config''}}}
!!!! Search all networking configuration files on the class shell server for an IP address:
{{Command{egrep '((1?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])\.){3}(1?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])' /etc/sysconfig/network-scripts/ifcfg-*}}}
It's important to understand how the metacharacters differ between file globbing and regular expressions. In regular expressions, the {{Monospaced{'' ? ''}}} or {{Monospaced{'' * ''}}} modify the atom immediately before them. For example, in the IP address above, the {{Monospaced{'' ? ''}}} in {{Monospaced{'' 1?[0-9]?[0-9] ''}}} means both the {{Monospaced{'' 1 ''}}} and the {{Monospaced{'' [0-9] ''}}} range are optional. In file globbing, the {{Monospaced{'' ? ''}}} or {{Monospaced{'' * ''}}} stand alone and represent either one single character or 0 or more characters by themselves.
The regular expression to identify an IP address is rather complex. We can't just do {{Monospaced{'' [0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3} ''}}} if we're only trying to match IP addresses and call it a day. This one would work to identify a proper IP like 192.168.0.1 but would also match an invalid IP address like 555.555.555.555.
To break this regex down piece by piece:
{{{
((1?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])\.){3}(1?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])
^ ^ ^ ^ ----------- -------^ ^ ^ ---------------------------------
| | | | ^ ^ | | | ^-- Repeat the first group again to identify a single octet without the dot at the end.
| | | | | | | | |--- Repeat the previous group within the ( ) three times for the first three octets
|---------------------------------|-------- These ( ) are used for alternation with the |, eg: (This|or|that) will match one of those three words.
| | | | | |------ Escape the dot so it's actually just a dot and cannot represent any single character
| | | | |------------ Match an octet from 250-255
| | | |---------------------- Match an octet from 200-249
| | |------------------------------- Notice the lack of the ?. We must have at least a single digit in each octet
| |---------------------------------- The ? makes the [0-9] optional. This would allow for a two digit IP address
|---------------------------------------- This optional 1 allows for octets in the 100-199 range
}}}
! Assignment
!! Read:
* Chapter 20 in //Harley Hahn's Guide to Unix and Linux//
!! Complete:
* Labs [[Lab 26|labs/lab26.pdf]] & [[Lab 27|labs/lab27.pdf]]
! Regex Examples:
!! Things to keep in mind:
* By default, regular expressions are greedy
** Example: Lock user accounts in the shadow file
* Difference between {{Monospaced{[ab]*}}} and {{Monospaced{(a*|b*)}}}
* Differences between globbing and regex:
** Files that start with a and end in t ''vs.'' regex meaning (show words that begin with a and end in k)
** Files that are three characters long, starting with a and ending with k ''vs.'' regex meaning (show words that are three characters beginning with a and end in k)
!! 1. Basic Pattern matching
* QEMU mac addresses
* Extract B&W printers in KH C-wing
!! 2. Input verification
* Examples from last week's regex page
* Fix the 12hr clock
** Expand to 24hr
!! 3. Complex substitutions (search & replace)
* Captures for later replacement
* Add the $ to money
** Standardize phone numbers in a list to (123)123-1234 format
*** How can we properly match for a {{Monospaced{.}}} as the delimiter?
** Examine the file /opt/pub/cs307/data/www/mstel-rqmts.html. Using line 27 as an example, create links for the remaining telecom course titles in that block. Your solution should not involve multiple uses of the ex substitution command.
!! 4. Substring extractions
* cc911 standby
!! Useful reference:
* https://regexcrossword.com/
* https://gregable.com/p/regexp-puzzle.html
* https://regex101.com/
! Lab links:
Part 1: Labs [[Lab 28|labs/lab28.pdf]] & [[Lab 29|labs/lab29.pdf]]
Part 2: Labs [[Lab 30|labs/lab30.pdf]]
Next week: [[Lab 31|labs/lab31.pdf]] - [[Lab 31 info|labs/lab31-cc911.pdf]]
Like most wikis, TiddlyWiki supports a range of simplified character formatting:
| !To get | !Type this |h
| ''Bold'' | {{{''Bold''}}} |
| ==Strikethrough== | {{{==Strikethrough==}}} |
| __Underline__ | {{{__Underline__}}} (that's two underline characters) |
| //Italic// | {{{//Italic//}}} |
| Superscript: 2^^3^^=8 | {{{2^^3^^=8}}} |
| Subscript: a~~ij~~ = -a~~ji~~ | {{{a~~ij~~ = -a~~ji~~}}} |
| @@highlight@@ | {{{@@highlight@@}}} |
| Tiddler Comments | {{{/%}}} text {{{%/}}}. |
| [[Make me a tiddler]] | {{{[[Make me a tiddler]]}}} |
| ~NoTiddler | {{{~NoTiddler}}} |
| {{{This is monotype}}} | {{{{{{This is monotype}}}}}} |
*sample:
|!th1111111111|!th2222222222|
|>| colspan |
| rowspan |left|
|~| right|
|bgcolor(#a0ffa0):colored| center |
|caption|c
For advanced effects, you can control the CSS style of a table by adding a row like this:
{{{
|cssClass|k
}}}
<<<
The highlight can also accept CSS syntax to directly style the text:
@@color:green;green coloured@@
@@background-color:#ff0000;color:#ffffff;red coloured@@
@@text-shadow:black 3px 3px 8px;font-size:18pt;display:block;margin:1em 1em 1em 1em;border:1px solid black;Access any CSS style@@
<<<
!!@@display:block;text-align:center;centered text@@
//For backwards compatibility, the following highlight syntax is also accepted://
{{{
@@bgcolor(#ff0000):color(#ffffff):red coloured@@
}}}
@@bgcolor(#ff0000):color(#ffffff):red coloured@@
/*{{{*/
@@color(yourcolorhere):colored text@@
@@color(fuchsia):colored text@@
@@bgcolor(yourcolorhere):your text here@@
[img[title|filename]]
[img[filename]]
[img[title|filename][link]]
[img[filename][link]]
[[text|url]]
[[Existing Tiddler Name|UglyTiddlerName]]
<<macro>>
<hr> = ----
*Entry One
**Sub-entry A
***Sub-sub-entry i
***Sub-sub-entry ii
**Sub-entry B
*Entry Two
*Entry Three
Use number signs (#'s) instead of asterisks for <OL type=1>
Tables:
|!Headings: add an exclamation point (!) right after the vertical bar.|!Heading2|!Heading3|
|Row 1, Column 1|Row 1, Column 2|Row 1, Column 3|
|>|>|Have one row span multiple columns by using a >|
|Have one column span multiple rows by using a ~|>| Use a space to right-align text in a cell|
|~|>| Enclose text in a cell with spaces to center it |
|>|>|bgcolor(green):Add color to a cell using bgcolor(yourcolorhere):|
|Add a caption by ending the table with a vertical bar followed by a c|c
!Header 1
!!Header 2
!!!Header 3
!!!!Header 4
!!!!!Header 5
Here's the code for a blockquote:
<<<
Here's the quoted text.
<<<
/*}}}*/
!Links
[[Calendar generator|http://zrenard.com/tiddlywiki/cal.php]]
Entities in HTML documents allow characters to be entered that can't easily be typed on an ordinary keyboard. They take the form of an ampersand (&), an identifying string, and a terminating semi-colon (;). There's a complete reference [[here|http://www.htmlhelp.com/reference/html40/entities/]]; some of the more common and useful ones are shown below. Also see [[Paul's Notepad|http://thepettersons.org/PaulsNotepad.html#GreekHtmlEntities%20HtmlEntitiesList%20LatinHtmlEntities%20MathHtmlEntities]] for a more complete list.
|>|>|>|>|>|>| !HTML Entities |
| &nbsp; | | no-break space | | &apos; | ' | single quote, apostrophe |
| &ndash; | – | en dash |~| &quot; | " | quotation mark |
| &mdash; | — | em dash |~| &prime; | ′ | prime; minutes; feet |
| &hellip; | … | horizontal ellipsis |~| &Prime; | ″ | double prime; seconds; inches |
| &copy; | © | Copyright symbol |~| &lsquo; | ‘ | left single quote |
| &reg; | ® | Registered symbol |~| &rsquo; | ’ | right single quote |
| &trade; | ™ | Trademark symbol |~| &ldquo; | “ | left double quote |
| &dagger; | † | dagger |~| &rdquo; | ” | right double quote |
| &Dagger; | ‡ | double dagger |~| &laquo; | « | left angle quote |
| &para; | ¶ | paragraph sign |~| &raquo; | » | right angle quote |
| &sect; | § | section sign |~| &times; | × | multiplication symbol |
| &uarr; | ↑ | up arrow |~| &darr; | ↓ | down arrow |
| &larr; | ← | left arrow |~| &rarr; | → | right arrow |
| &lArr; | ⇐ | double left arrow |~| &rArr; | ⇒ | double right arrow |
| &harr; | ↔ | left right arrow |~| &hArr; | ⇔ | double left right arrow |
The table below shows how accented characters can be built up by subsituting a base character into the various accent entities in place of the underscore ('_'):
|>|>|>|>|>|>|>|>|>|>|>|>|>|>|>|>|>| !Accented Characters |
| grave accent | &_grave; | À | à | È | è | Ì | ì | Ò | ò | Ù | ù | | | | | | |
| acute accent | &_acute; | Á | á | É | é | Í | í | Ó | ó | Ú | ú | | | Ý | ý | | |
| circumflex accent | &_circ; | Â | â | Ê | ê | Î | î | Ô | ô | Û | û | | | | | | |
| umlaut mark | &_uml; | Ä | ä | Ë | ë | Ï | ï | Ö | ö | Ü | ü | | | Ÿ | ÿ | | |
| tilde | &_tilde; | Ã | ã | | | | | Õ | õ | | | Ñ | ñ | | | | |
| ring | &_ring; | Å | å | | | | | | | | | | | | | |
| slash | &_slash; | | | | | | | Ø | ø | | | | | | | |
| cedilla | &_cedil; | | | | | | | | | | | | | | | Ç | ç |
<HTML><a href="http://checkettsweb.com/#%5B%5BCSS-Colors%20and%20Backgrounds%5D%5D%20%5B%5BCSS-Text%20and%20Fonts%5D%5D%20OldStyleSheet%20Rin%20%5B%5BTiddlyWiki%20Structure%5D%5D">CSS Info</a></html>
<<version>>
[[Plugins]]
[[Styles]]
[[TagglyTagging]]
[[systemConfig]]
[[systemTiddler]]
[[excludeSearch]]
[[excludeLists]]
! Material
This page will discuss two topics:
1. Authenticating to Unix systems with SSH keys
2. Terminal multiplexing with GNU {{Command{screen}}}
These are both optional, but good to know and will make working with our lab systems much easier.
!! 1. Authenticating to Unix systems with SSH keys
Two mechanisms exist for SSH authentication:
# normal passwords
# key pairs used in asymmetric encryption
A key pair contains a private key that you keep secure and a public key that is distributed to the systems you have permission to connect to. The private key you have is used to establish your identity. The presence of your public key on a remote system is used to establish your authorization to access it. Private keys should be secured with a passphrase to ensure they cannot be maliciously used if they are captured by an attacker. SSH authentication with passphrase-protected key pairs is much safer than passwords, since now an attacker must also capture the private key file in order to impersonate you. For this reason, it is common to minimally block password authentication to a server when logging in as root or ideally only allow key authentication for all users. More sensitive systems should require key-based authentication as part of general system hardening.
Forcing key-based authentication gives us multi-factor authentication (MFA) when the key is properly secured with a passphrase:
# Something you have (the private key)
# Something you know (the key's passphrase)
We begin by creating a SSH keypair on the class shell server.
{{Command{cd ~/.ssh/}}}
<<<
Change to the ~/.ssh/ directory, the default location for a user's ssh configuration files.
<<<
{{Command{ssh-keygen -t ed25519 -f cs307 }}}
<<<
Create a SSH key pair using default settings, except for changing the key type to ed25519 and naming the key cs307. The algorithm and key size can also be adjusted via flags. The remaining defaults are reasonable. You will be prompted to set a passphrase. Choose something secure which you can remember. This [[xkcd cartoon|https://xkcd.com/936/]] may be helpful. The more entropy the better.
<<<
{{Command{ssh-copy-id -i cs307 root@192.168.12.''//x//''}}}
<<<
Copy your public key to each of your ~VMs. It will be saved to the file {{File{~/.ssh/authorized_keys}}} on the remote system (your VM). The administrator may have to add the key for you on systems you're not able to log into yet.
<<<
{{Command{ssh -l root 192.168.12.''//x//''}}}
<<<
Try to connect to your test VM. You should be prompted for a password since our private key is not in the default location and was not specified on the command line.
<<<
{{Command{ssh -i cs307 -l root 192.168.12.''//x//''}}}
<<<
You should now be prompted for your SSH passphrase instead of password. If an available and authorized SSH key is found it will be offered for use instead of your password. Authentication will fall back to regular password if key-based fails.
<<<
{{Command{exit}}}
<<<
Disconnect from your VM
<<<
Having to specify the username and key file to use for each login to your ~VMs can be eliminated by using a ssh client configureation. Edit {{File{~/.ssh/config}}} on the shell server and set a default username and ssh key for class ~VMs
Edit the file {{File{~/.ssh/config}}} and add the following:
{{{
Host test
HostName 192.168.12.x
Host www
HostName 192.168.12.x
Host *
IdentityFile ~/.ssh/cs307
User root
}}}
Be sure to change the x above to your actual IP address. This addition will also eliminate the need for specifying full IP addresses for each connection. You'll be able to then connect with just {{Command{ssh //hostname//}}} and the IP address, user, and key file will be added for you. Add new ~VMs to the config as they are issued to you.
!!! SSH agent - Unlock your key once for multiple connections
The SSH agent is a keyring which your SSH private keys can be attached to. Once set up, future connections will look to that key ring when an authentication request is made instead of prompting you for your SSH passphrase each time. The idea is one authentication event for many remote connections.
{{Command{ssh-agent > ~/.ssh/env}}}
<<<
Create a SSH agent, saving the environment information to the specified file. This environment must be imported in order to make use of the agent.
<<<
{{Command{eval `cat ~/.ssh/env`}}}
<<<
Import the environment settings into the current shell environment
<<<
{{Command{ssh-add ~/.ssh/cs307}}}
<<<
Add your cs307 private key to your ssh agent keyring. You should be prompted for its passphrase.
<<<
Once the SSH agent is established you may communicate to your lab systems without being prompted to authenticate each time. Notice the lack of passphrase prompts:
{{Commands{
[merantn@shell ~]$ ''ssh test''
Last login: Mon Oct 19 15:18:26 2020 from 192.168.12.10
[root@test ~]# ''exit''
logout
Connection to 192.168.12.24 closed.
[merantn@shell ~]$ ''ssh www''
Last login: Mon Oct 19 15:19:51 2020 from 192.168.12.10
[root@www ~]# ''exit''
logout
Connection to 192.168.12.25 closed.
}}}
!! 2. Terminal multiplexing with GNU screen
GNU {{Command{screen}}} is a very useful tool for those working with the command line on many systems from different locations on a daily basis. From within {{Command{screen}}}, connections can be made to many systems. The user can detach from the screen session, change physical locations, and reconnect to their screen session continuing work where they left off. GNU {{Command{screen}}} and ssh agents make a great combination for connecting to multiple machines over the course of your work day.
This video might help get you started: https://www.youtube.com/watch?v=Mw6QvsChxo4
{{Command{cp ~merantn/.screenrc ~/}}}
<<<
Copy this default screen configuration file to your home directory. This will establish some baseline settings.
<<<
If you first run the steps in Section 1 to set up ssh-agent and then launch {{Command{screen}}} to start your screen instance, your SSH Agent will be established for all screen windows. You thus will not need to authenticate to your ~VMs as you move between them. You will only need to run the {{Command{screen}}} command without any options once. It will stay active with your tasks running in the background until you either terminate it or the class shell server restarts.
Screen commands:
| !Key Sequence | !Action |
| ~CTRL-a , 0 |Switch to window 0|
| ~CTRL-a , 1 |Switch to window 1|
| ~CTRL-a , 2 |Switch to window 2|
| ~CTRL-a , //n// |Switch to window //n//|
| ~CTRL-a , c |Create a new screen window|
| ~CTRL-a , " |Display available screen windows|
| ~CTRL-a , ' |Switch to a screen window by number|
| ~CTRL-a , A |Title the current screen window|
| ~CTRL-a , ? |Display screen help|
With screen now running, enter these screen commands to get things set up:
* Create a new window: {{Command{~CTRL-a, ~CTRL-c}}}
* Switch to window 1: {{Command{~CTRL-a, 1}}}
** Connect to your test VM with ssh
* Create a new window: {{Command{~CTRL-a, ~CTRL-c}}}
* Switch to window 2: {{Command{~CTRL-a, 2}}}
** Connect to your www VM with ssh
* Switch to window 0: {{Command{~CTRL-a, 0}}}
** Use this window to work on the class shell server
* Detach from screen (as if you're done working for the day): {{Command{~CTRL-a, d}}}
* Reconnect to your screen session (as though you're coming back later to continue work): {{Command{screen -dr}}}
Now, when you disconnect from the shell server, all of your tasks will stay running in the background. Log in again and run {{Command{screen -dr}}} to continue where you left off. Create new windows inside of screen as you need them for new ~VMs or to run additional tasks concurrently.
More screen commands:
| !Key Sequence | !Action |
| ~CTRL-a , | |Split window vertical|
| ~CTRL-a , S |Split window horizontal|
| ~CTRL-a , TAB |Switch between split windows|
| ~CTRL-a , X |Close a split window|
|>|>|
| ~CTRL-a , d |Detach from screen|
| ~CTRL-a , :password |Set a password for your screen session|
{{Note{[[This video|SSH]] may be a helpful demonstration}}}
3. Defeating firewalls with SSH to access protected resources
See the [[Tunnels & Proxies with SSH]] page.
/%
!! 1. Authenticating to Unix systems with SSH keys
Two different sets of keys are used with SSH: one for securing communication between the client and server and, optionally, a set to authenticate remote users.
!!! SSH Host keys
* Public key crypto is used for encrypting communication between client and server
* Server keys are stored in the files {{File{/etc/ssh/ssh_host_*}}}
* Fingerprints for new systems are shown and stored in the user's {{File{~/.ssh/known_hosts}}} file. This keeps a record of trusted systems.
** This file can leak identities of systems you are communicating with
** Hash your current known hosts file if you'd like to mask the systems: {{Command{ ssh-keygen -H }}}
* Fingerprints for known systems are compared on each login to identify MITM attacks
** The user is alerted if a mismatch is found
*** This is the warning you see if you connect to a new system for the first time or there's a server change when connecting to an existing system.
** The user should take steps to verify the host key has legitimately changed. If this change is due to a MITM attack, the attacker could capture your credentials
** Display the fingerprint of a SSH public key: {{Command{ssh-keygen -lf //file//.pub}}}
!!!! Demo:
{{Monospaced{
[merantn@shell ~]$ ''ssh head.cs307.net''
The authenticity of host 'head.cs307.net (192.168.12.15)' can't be established.
ECDSA key fingerprint is ~SHA256:bHKouQIItQNr5r1Im3tI0uk2ArpfYU1Yvop0SQhOLVY.
ECDSA key fingerprint is ~MD5:9f:0d:9c:2d:f6:2c:ef:9e:6a:bb:ab:e5:4b:c5:55:e4.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'head.cs307.net' (ECDSA) to the list of known hosts.
# You can't log into this system, so press ~CTRL-C to abort:
merantn@head.cs307.net's password:
# Here's the fingerprint of this system:
[merantn@shell ~]$ ''grep head ~/.ssh/known_hosts''
head.cs307.net ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBBhZIx/NElfvUL0nI/KwOotqk5Fypf01LQpn8YIe7FfXI8xnwEzESmqZTOiC791SrvOaoIxIFu9WW9xO7+BcgSw=
# Hash the hosts in the file:
[merantn@shell ~]$ ''ssh-keygen -H''
/home/merantn/.ssh/known_hosts updated.
Original contents retained as /home/merantn/.ssh/known_hosts.old
WARNING: /home/merantn/.ssh/known_hosts.old contains unhashed entries
Delete this file to ensure privacy of hostnames
Now a grep returns no results:
[merantn@shell ~]$ ''grep head ~/.ssh/known_hosts''
}}}
%/
! Additional Details
This video is a deep dive into SSH and has a lot of great info: https://www.youtube.com/watch?v=fnkG9_jy2qc
! Wrapping up
!! Closing out the semester
!!! VM deletion
Our lab environment for this class will be decommissioned on ''Saturday, Dec 28''. If there is anything you would like to complete or back up, please do so by then. Please let me know if there's anything you need help saving.
!!! Additional Resources
!!!! A lab environment similar to ours can easily be replicated from open source tools:
* [[Proxmox|https://www.proxmox.com/en/]]: The hypervisor our ~VMs are running on. Works great on a spare server or PC that's kicking around.
* [[Naemon|https://www.naemon.org/]]: Infrastructure monitoring
* [[SaltStack|https://www.saltstack.com/]]: Infrastructure Management & Orchestration - I used this to easily run commands on all class ~VMs and maintain baseline configurations
* [[NameCheap|https://www.namecheap.com]]: Domain Registration - A simple, clean interface and free domain privacy.
* [[DigitalOcean|https://www.digitalocean.com/]]: Low cost cloud ~VMs - I use these for my personal infrastructure. Good Linux ~VMs for $6 per month.
* [[Hetzner|https://www.hetzner.com/sb?country=us]]: Low-cost bare metal cloud servers. This is the hosting provider for our current class lab environment.
!!! Class website mirror
The entire class website runs from a single HTML file. A zip file containing the HTML file along with linked images, videos, and lab ~PDFs can be downloaded from https://www.ncs205.net/ncs205.zip
* Last updated 12/17/24 @ 20:45
/% - The link will be live once finals end - %/
/%!!! Feedback
I hope everyone enjoyed this class and got something useful from it. The material I included is the highlights of what you'll need to be exposed to if you'll be using Linux in and beyond the NCS program. If you have any feedback to offer, good or bad, please let me know. I'm always looking for ways to improve the class for the next semester. %/
Type the text for 'excludeLists'
Type the text for 'excludeSearch'
!!!! [[hack6 break-in]]
A VM named ''hack6'' has just been added for each of you. It's presently powered on and assigned to the last IP address of your range via DHCP.
This VM has information which can be found and vulnerabilities which can be exploited to gain access. All required knowledge is based on our class material. Information disclosure will yield the first three flags and a vulnerability can be exploited to ultimately obtain root-level access. There's flags to capture as your intrusion progresses to show you have increasingly gained access and to show how far you were able to get.
Access hack6 for a little CTF (capture the flag). These CTF challenges are a fun way to demonstrate skill, creativity, and understanding of the material.
* This VM is currently running on the last IP address of your range
** Create an A record so host name hack6 points to this IP address
* The ultimate objective is to break into the system and gain full root privileges.
* Flags to capture are in the following files:
** {{File{flag1.txt}}}
** {{File{flag2.txt}}}
** {{File{/home///user///flag3.txt}}}
** {{File{/root/flag4.txt}}}
** //user// is a placeholder for a valid user on the system. Flag 3 is in one of the system user's home directories.
** The "flag" to capture is the string of text located inside each of those four files. It will look something like this: {{Monospaced{ ''flag{//sometext//}'' }}}
What's the highest number flag you can access? Capturing all four shows you have root-level access and have fully taken over the system.
The first two flags can be obtained by interacting with services running on the VM. The second two flags can be obtained after gaining shell access to the VM.
* Don't overthink it; the flags (especially the first three) only require basic interaction with the system
* Everyone seems to first gravitate towards brute-force tactics. This is the path of the unskilled. These are actually rarely successful when targeting a specific system or account and will not help you here.
This challenge will primarily draw from material covered [[Week 15, Part 2]] (Access control and user management), [[Week 15, Part 1]] (Scheduled Tasks), and Section 1 of [[Working more efficiently with GNU screen & SSH keys]] (Authenticating to Unix systems with SSH keys)
* And will require a bit of creativity
* Linux Administration Chapter 23 also contains a lot of good info on SSH
* The {{Command{nmap}}} command can be used to scan a system to identify listening services. The basic syntax is {{Command{nmap //ip_address//}}}.
** You will need to interact with those services to obtain shell access. You will not see this VM in the Proxmox UI and do not have a user account's password to log in directly.
Most system intrusions take advantage of misconfiguration to gain a higher level of access. Developing an understanding of how things work is necessary for a defender to properly configure (and thus secure) their systems. Understanding how things work also makes it easier for an attacker to exploit any misconfigurations.
The first two flags will be found through basic system discovery & information disclosure. Flag 2 will be accompanied by your key into the VM. The final flag and full system compromise will be obtained by exploiting a system misconfiguration.
The path to full system compromise is linear. All flags will need to be obtained in order. There is only one route to obtain the first three flags. There are two different ways to obtain the fourth. Can you find both misconfigurations which will grant root access?
!!!! Grading
The Final Exam will be worth 20 points. The point breakdown for the flags and responses is:
* Flags 1 & 2: 5 points each
* Flag 3: 2 points
* Flag 4: 3 points
* Page 3 question: 5 points
Standard rules for lab assignments apply. The deliverable PDF must contain your name at the top of the first page and must be properly submitted; it must be uploaded to the correct directory on the class shell server and given the correct filename. These skills were part of the material this semester and are thus in scope for the Final exam content. No points will be awarded if these requirements are not completed correctly. The grading queue is visible and can be used as verification that the deliverable PDF was properly collected for evaluation.
!!!! Deliverable:
Complete and submit [[Final Exam|exam/ncs205-final.pdf]] with your steps and flag contents. Upload the PDF to the class shell server to the directory {{File{/opt/pub/ncs205/submit/final/}}}. The file name must be {{File{ncs205-final-//username//.pdf}}}.
@@ ''The final exam write-up will be due by EOD Thursday, May 2'' @@
Consider pacing this out over a longer period of time. With tasks like this, it's sometimes helpful to step away for a bit if you get stuck. That'll give you some time to think about it in the background or come back later with a fresher set of eyes and perspective.
!! less
| !Command | !Action |
| Page Up or ''b'' | Scroll back one page |
| Page Down or space | Scroll forward one page |
| Up arrow | Scroll up one line |
| Down arrow | Scroll down one line |
| ''G'' | Move to the end of the text file |
| ''1G'' or ''g'' | Move to the beginning of the text file |
| /characters | Search forward to the next occurrence of //characters// |
| ''n'' | Search for the next occurrence of the previous search |
| ''h'' | Display help screen |
| ''q'' | Quit less |
config.macros.listTags = { text: "Hello" };
config.macros.listTags.handler = function(place,macroName,params)
{
var tagged = store.getTaggedTiddlers(params[0],params[1]);
//<< Second parameter is field to sort by (eg, title, modified, modifier or text)
var ul = createTiddlyElement(place,"ul",null,null,"");
for(var r=0;r<tagged.length;r++)
{
var li = createTiddlyElement(ul,"li",null,null,"");
createTiddlyLink(li,tagged[r].title,true);
}
}
/***
|''Name:''|Plugin setDefaults|
|''Version:''|1.0.1 (2006-03-16)|
|''Source:''|http://tiddlywikitips.com/#%5B%5BPlugin%20setDefaults%5D%5D|
|''Author:''|Jim Barr (jim [at] barr [dot] net)|
|''Licence:''|[[BSD open source license]]|
|''TiddlyWiki:''|2.0|
|''Browser:''|Firefox 1.0.4+; Firefox 1.5; InternetExplorer 6.0|
!Description
These settings simply set "default" values for several system features and Plugins.
***/
/***
Standard settings:
***/
//{{{
config.options.chkRegExpSearch = false; // default false
config.options.chkCaseSensitiveSearch = false; // default false
config.options.chkAnimate = false; // default true
//config.options.txtUserName = "Nick"; // default "YourName"
config.options.chkSaveBackups = false; // default true
config.options.chkAutoSave = false; // default false
config.options.chkGenerateAnRssFeed = false; // default false
config.options.chkSaveEmptyTemplate = false; // default false
config.options.chkOpenInNewWindow = true; // default true
config.options.chkToggleLinks = false; // default false
config.options.chkHttpReadOnly = true; // default true
config.options.chkForceMinorUpdate = false; // default false
config.options.chkConfirmDelete = true; // default true
config.options.txtBackupFolder = ""; // default ""
config.options.txtMainTab = "tabTimeline"; // default "tabTimeline"
config.options.txtMoreTab = "moreTabAll"; // default "moreTabAll"
config.options.txtMaxEditRows = "30"; // default "30"
config.options.chkInsertTabs = true; // tab inserts a tab when editing a tiddler
//}}}
/***
Custom Plugin settings:
***/
//{{{
config.options.chkSinglePageMode = false; // default "true"
config.options.chkSearchTitlesFirst = true;
config.options.chkSearchList = true; // default "false"
config.messages.messageClose.text = "X"; // default "close"
// config.views.wikified.defaultText = ""; // default "The tiddler '%0' doesn't yet exist. Double-click to create it"
config.options.chkStepWiseNavigationOn = true; // default "false"
config.options.chkDisableAutoSelect =true;
config.options.chkTextAreaExtensions =true;
//}}}
Type the text for 'systemConfig'
Type the text for 'systemTiddler'