% CST8207 Week 07 Notes -- Inodes, Hard links, Disk usage, quotas, symbolic links, modes, permissions, chmod % Ian! D. Allen -- -- [www.idallen.com] % Winter 2017 - January to April 2017 - Updated 2017-03-13 09:12 EDT - [Course Home Page] - [Course Outline] - [All Weeks] - [Plain Text] Readings, Assignments, Labs, Tests, and ToDo ============================================ Read (at least) these things (All The Words) -------------------------------------------- 1. [Week 07 Notes HTML] -- this file -- **Read All The Words** 2. [Unix/Linux File System] -- directories, inodes, hard links 3. [Hard links and Unix/Linux file system index nodes (inodes)] 4. [Unix/Linux Disk Usage, Hard Links, Quotas, Finding Inodes] 5. [Symbolic Links] 6. [Unix Modes and Permissions, whoami, id, groups, ls -l, chmod] 7. [Permissions masking with umask, chmod, 777 octal permissions] 8. [List of Commands You Should Know] 9. [Linux and Sysadmin News in the World] 10. [Video Tutorials on Lynda.com] -- tagged by week number - Create your [lynda.com] account and watch these sections of [Unix for Mac OS X Users] - these videos are for *all* Unix/Linux students, not just Mac OSX users - **3. Working with Files and Directories** - Naming files 5m 41s - use quotes to surround names with blanks or special characters - Hard links 5m 30s - Symbolic links 6m 36s - **4. Ownership and Permissions 34m 58s** - Who am I? 4m 3s - `whoami` - Unix groups 1m 52s - `groups` - File and directory ownership 6m 41s - `ls -la` - you do not have permission to use `chown`, `sudo`, or `su` on the CLS - File and directory permissions 4m 27s - `rwx` notation - Setting permissions using alpha notation 6m 49s - `chmod` - Setting permissions using octal notation 3m 49s - ``` chmod 644 ``[names...] ``` - **5. Commands and Programs** - The PATH variable 4m 13s - Disk information commands 6m 8s - df, du, - **7. Configuring Your Working Environment 41m 28s** - Setting the PATH variable 6m 10s - using double quotes instead of single quotes Assignments and lab work this week ---------------------------------- Check the due date for each assignment and put a reminder in your agenda, calendar, and digital assistant. Just like in the Real World, not all due dates are on the same days or at the same times. - Review last week. Did you do everything assigned last week? - Finish work on the ODT or PDF [Worksheet #04 HTML] and [Worksheet #05 HTML] so you can do [Assignment #05 HTML] -- GLOB wildcard patterns, finding files using GLOB, redirection and pipes - These all require you to understand [Finding Files], [Shell GLOB patterns] (wildcard pathname matching) and [Shell I/O Redirection] (including Pipes). - [Assignment #07 HTML] is about start-up files, environment, search PATH, quoting, hard and soft links, disk usage - Do [Worksheet #08 HTML] to prepare for [Assignment #08 HTML] -- setting permissions, mode, `umask` - This assignment requires material not yet fully covered in lectures: [Permissions][Unix Modes and Permissions, whoami, id, groups, ls -l, chmod], [Umask][Permissions masking with umask, chmod, 777 octal permissions] - Do Bonus (optional) [Assignment #06 HTML] about Midterm #1 - There is a checking program available to check your file format for this bonus assignment, but only people who Read All These Words will know about it. Wrong format means no marks. *Do not redirect the output of this checking program!* - Read [The VI (VIM) Text Editor] and optionally do the bonus [Assignment #04 HTML]. Worksheets ---------- Worksheets are preparation for your assignments. You can't do the assignments without having done the worksheets first, and you can't do the worksheets without having first read the Course Notes: 1. Read the web notes. (Please: **Read All The Words**) 2. Do the relevant Worksheet(s). 3. Do the relevant Assignment(s). Form a small study group to do the worksheets. Each person tries the example given, and you make sure you all get the same answers. Worksheets are not for hand-in; they are not worth marks; the assignments test your knowledge of the lectures and worksheets. > The worksheets are available in four formats: Open Office (ODT), PDF, HTML, > and Text. Only the Open Office format allows you "fill in the blanks" in > the worksheet. The PDF format looks good but doesn't allow you to type into > the blanks in the worksheet. The HTML format is crude but useful for quick > for viewing online. Do **NOT** open the Worksheet ODT files using any Microsoft products; they will mangle the format and mis-number the questions. Use the free Libre Office or Open Office programs to open these ODT documents. On campus, you can [download Libre Office here]. - [Worksheet #04 ODT] -- shell GLOB patterns and Aliases - [Worksheet #04 PDF] - [Worksheet #04 HTML] - shell GLOB patterns (wildcards), Aliases: `alias, sum, unalias` - [Worksheet #05 ODT] -- shell I/O redirection (including pipes) - [Worksheet #05 PDF] - [Worksheet #05 HTML] - shell I/O redirection, `date, head, nl, tail, tr, wc` - [Worksheet #06 HTML] -- *Optional* Bonus VIM Text Editor Practice - This is an *optional* worksheet for a BONUS assignment using `vim` - Optional command-line VIM tutorial: the `vimtutor` program on the CLS. - Bonus (optional) [Assignment #04 HTML] -- the VIM text editor - Read [The VI (VIM) Text Editor] - [Worksheet #08 ODT] -- Linux file system permissions (modes) - This Worksheet is a prerequisite for [Assignment #08 HTML] - [Worksheet #08 PDF] -- PDF version - [Worksheet #08 HTML] -- HTML version - `chmod, ls -lid, umask` Worksheets prepare you for the upcoming assignments. Upcoming tests and exams ------------------------ ![Bring your favourite marker to your test] This course has two midterm tests and one final exam. - Put these dates below into your phone! - Read the [Test Instructions] (all the words) before your tests and exam. - Use the **Name Game** link (in the [Test Instructions]) to test the spelling of your name before the test. - I don't answer questions about the instructions during the test. Ask me in a lab period before the test. ### Second Midterm test -- 10am March 17 -- 15% Your Second Midterm test is 45 minutes long and contains approximately 45 multiple-choice questions similar to those found in the two preceding [Practice Tests and Answers]. Do *both* practice tests before the Second Midterm test! - Time: 10h00-10h45 (10am to 10:45am) Friday March 17 (Week 9) - Location: C346 (the usual lecture classroom) - General seating; sit anywhere. - 45 minutes for 45 questions - Do *both* the practice tests before the Midterm test! *Midterm tests take place at 10am in your 50-minute lecture class, not in your lab period.* ### The Final Exam -- 8am April 28 -- 40% The Final Exam is three hours long and contains approximately 180 multiple-choice questions similar to those found in the three preceding [Practice Tests and Answers]. Do *all three* practice tests before the Final Exam! - Time: 08h00-11h00 (8am to 11am) Friday April 28 (Week 15) - Location: CA-105 A,B,C (across the Woodroffe pedestrian overpass) - This exam has **assigned seating** -- see your email for your assigned seat. - 180 minutes (three hours) for 180 questions - Do *all three* practice tests before the Final Exam! - Three Hours! Take a bathroom break before you start the exam! All three practice tests will be posted under [Practice Tests and Answers]. The Final Exam is comprehensive of the whole course; you need to do *all three* practice tests for the Final Exam. Notes from the Classroom ======================== - **Take notes in class!** Keep a pad open on your desk. Commands Used ------------- - Keep a notebook with a [List of Commands][List of Commands You Should Know] in it. - You need to write down yourself what each command *does*. - Check the updated list of commands each week. - Bring your notes to class! Stop wasting time looking up commands. - I will check for this list in your lab periods. - Are you making notes from the worksheets on how each command works? - What do the options used in the worksheets mean, for each command? - Don't copy and use options that you don't understand! - Know (for the assignment) the three commands that are [directory operations][Hard links and Unix/Linux file system index nodes (inodes)] that manipulate file names; they don't touch the file data and don't need any permissions on the file data. Your own web page ----------------- This is part of the upcoming [Assignment #08 HTML]. You can do it now. - [Create your own web page!] - You will need to use `chmod 755` on your `public_html` directory. - Your web page will be visible on the Internet using a web browser to access URL `http://cst8207.idallen.ca/~``abcd0001` where *abcd0001* is replaced with your CLS userid. (There is a tilde character in that URL.) - Example: Searching the course notes ========================== I received an email like the text below from a student who was working on a problem for over two hours: > I have spent almost 2 hours on Task 4.6 and I still can't find the 100 > files. \[...\] I think the problem is searching for warez case-insensitive. > I know we learned this before, but I just can't find it in my notes. This is not good use of student time for two reasons: 1. Don't spend more than 15 minutes on a problem! Your time as a student is valuable. See the [Course Introduction: fifteen minute rule] 2. I showed you how to search the course notes for keywords in [Assignment #05 HTML]: - In section [3.2 Searching the course notes on the CLS] - In section [4.5 Searching for text inside files (e.g. course notes)] You have a search tool that will find keywords inside the course notes. Please use it and save yourself time. Tutoring ======== Many students find that hiring a personal tutor helps them get through the first term. Financial assistance is available. See the **Tutoring** heading in the [Course Introduction]. ![Take Notes in Class] -- | Ian! D. Allen, BA, MMath - idallen@idallen.ca - Ottawa, Ontario, Canada | Home Page: http://idallen.com/ Contact Improv: http://contactimprov.ca/ | College professor (Free/Libre GNU+Linux) at: http://teaching.idallen.com/ | Defend digital freedom: http://eff.org/ and have fun: http://fools.ca/ [Plain Text] - plain text version of this page in [Pandoc Markdown] format [www.idallen.com]: http://www.idallen.com/ [Course Home Page]: .. [Course Outline]: course_outline.pdf [All Weeks]: indexcgi.cgi [Plain Text]: week07notes.txt [Week 07 Notes HTML]: week07notes.html [Unix/Linux File System]: 450_file_system.html [Hard links and Unix/Linux file system index nodes (inodes)]: 455_links_and_inodes.html [Unix/Linux Disk Usage, Hard Links, Quotas, Finding Inodes]: 457_disk_usage.html [Symbolic Links]: 460_symbolic_links.html [Unix Modes and Permissions, whoami, id, groups, ls -l, chmod]: 500_permissions.html [Permissions masking with umask, chmod, 777 octal permissions]: 510_umask.html [List of Commands You Should Know]: 900_unix_command_list.html [Linux and Sysadmin News in the World]: 950_linux_world.html [Video Tutorials on Lynda.com]: 910_lynda_index.html [lynda.com]: http://algonquincollege.com/onlineresources/mobileStudent/lynda.htm [Unix for Mac OS X Users]: http://www.lynda.com/Mac-OS-X-10-6-tutorials/Unix-for-Mac-OS-X-Users/78546-2.html [Worksheet #04 HTML]: worksheet04.html [Worksheet #05 HTML]: worksheet05.html [Assignment #05 HTML]: assignment05.html [Finding Files]: 180_finding_files.html [Shell GLOB patterns]: 190_glob_patterns.html [Shell I/O Redirection]: 200_redirection.html [Assignment #07 HTML]: assignment07.html [Worksheet #08 HTML]: worksheet08.html [Assignment #08 HTML]: assignment08.html [Assignment #06 HTML]: assignment06.html [The VI (VIM) Text Editor]: 300_vi_text_editor.html [Assignment #04 HTML]: assignment04.html [download Libre Office here]: 050_course_introduction.html#install-libreoffice-or-openoffice-into-windows [Worksheet #04 ODT]: worksheet04.odt [Worksheet #04 PDF]: worksheet04.pdf [Worksheet #05 ODT]: worksheet05.odt [Worksheet #05 PDF]: worksheet05.pdf [Worksheet #06 HTML]: worksheet06.html [Worksheet #08 ODT]: worksheet08.odt [Worksheet #08 PDF]: worksheet08.pdf [Bring your favourite marker to your test]: data/sniff_markers.jpg "Bring your favourite marker to your test" [Test Instructions]: 000_test_instructions.html [Practice Tests and Answers]: PRACTICE_TEST_README.html [Create your own web page!]: 000_student_web_site.html [Course Introduction: fifteen minute rule]: 050_course_introduction.html#fifteen-minute-rule-dont-waste-your-time [3.2 Searching the course notes on the CLS]: assignment05.html#searching-the-course-notes-on-the-cls [4.5 Searching for text inside files (e.g. course notes)]: assignment05.html#searching-for-text-inside-files-e.g.course-notes [Course Introduction]: 050_course_introduction.html [Take Notes in Class]: data/remember.jpg "Take Notes in Class" [Pandoc Markdown]: http://johnmacfarlane.net/pandoc/