% CST8207 Week 07 Notes -- File System, Inodes, Hard links, Disk Usage, Symbolic Links, Midterm 1 Analysis % Ian! D. Allen -- -- [www.idallen.com] % Fall 2018 - September to December 2018 - Updated 2018-10-19 14:23 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. [File System] -- directories, index nodes (inodes), hard links 3. [Hard links] -- hard links, file system index nodes (inodes) 4. [Disk Usage] -- Hard Links, Quotas, Finding Inodes 5. [Symbolic Links] -- soft links work on directories and across file systems 6. Next Week: [Permissions] -- permissions, modes, whoami, id, groups, ls -l, chmod 7. [List of Commands] -- Command names you should know, listed by week 8. [Video Tutorials on Lynda.com] -- tagged by week number 9. [Linux and Sysadmin News in the World] - 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 - **5. Commands and Programs** - Disk information commands 6m 8s - df, du, Assignments 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? - Read All The Words, Do, and then Submit via Brightspace: - [Assignment #05 HTML] -- using GLOB wildcard patterns, selecting files using GLOB, redirection and pipes. This assignment requires reading [Shell GLOB patterns] and [Shell I/O Redirection] and then doing [Worksheet #04 HTML] and [Worksheet #05 HTML]. - [Assignment #07 HTML] -- start-up files, environment, search PATH, quoting This assignment requires reading the weekly readings first. - OPTIONAL: Read [The VI (VIM) Text Editor] and optionally do the bonus [Assignment #04 HTML] for extra credit. - Really do **Read All The Words**. You don't get a second chance to get it right. - OPTIONAL: Do Bonus [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 file format means no marks. *Do not redirect or save the output of this checking program!* Lab work this week ------------------ - Complete and save the ODT or PDF versions of [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 worksheets require you to understand [Finding Files], [Shell GLOB patterns] (wildcard pathname matching) and [Shell I/O Redirection] (including Pipes). - [Assignment #05 HTML] -- GLOB wildcard patterns, selecting files using GLOB, redirection and pipes - This assignment requires you to understand the material in the web pages and both Worksheets 4 and 5. - [Assignment #07 HTML] is about start-up files, environment, search PATH, and quoting - [Assignment #08 HTML] is about disk usage, hard links, and symbolic links - This coming assignment requires material not yet fully covered in lectures: [Symbolic Links], [Hard Links], [Disk Usage], - OPTIONAL: Do Bonus [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 file format means no marks. *Do not redirect or save the output of this checking program!* - OPTIONAL: Read [The VI (VIM) Text Editor] and optionally do the bonus [Assignment #04 HTML]. - **Reminder:** You must actually use the VIM editor during the term to get full marks for this bonus assignment. Read All The Words. ### 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). Make notes from the worksheets on *how each command works*. What do the options used in the worksheets mean, for each command? (See the weekly [List of Commands].) 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 get a copy here: [Course Introduction: Install Libre Office]. Worksheets #04 and #05 require you to have read [Shell GLOB patterns] and [Shell I/O Redirection]: - [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 is for the optional VIM Bonus Assignment (extra credit): - [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 is for the upcoming Assignment 9. - [Worksheet #08 ODT] -- Linux file system permissions (modes) - This Worksheet is a prerequisite for [Assignment #09 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 ------------------------ This course has two midterm tests (10%, 15%) and one final exam (40%). ![Bring your favourite marker to your test] Follow this link to see all your upcoming [Quizzes and Tests]. The dates are also posted on the [Course Home Page] and on [Brightspace CST8207]. For full marks, read the [Test Instructions] (all the words) **before** your midterm tests. 1. First Midterm test: Done. 2. Second Midterm test: 45 minutes; in your one-hour lecture class in Week 10. 3. Final Exam: The date is now posted on ACSIS: Thursday December 13 8am to 11am in the Gym. Midterm tests take place in your one-hour lecture class, not in your lab period. You must write the midterm test in the lecture class in which you are registered. Midterm Test #1 Analysis ======================== > I spent hours correcting your errors and omissions on your test papers. > Many of you lost marks for that. Before your next test, carefully re-read > the posted [Test Instructions]. Penalties go up for making the same errors > on the next tests. Here are some statistics for the first midterm test: - 227 students are currently registered in the course (October 16, 2018). Of the 227, 16 did not write the test, leaving 211 who did. - Of the 211, 9 did not enter a valid test version code on the Scantron form. I had to enter all those test version codes for you, so that you could get some marks. - Of the 211, 22 did not enter their own name to match the name on file in ACSIS with the Algonquin Registrar office. (These students didn't check their names using the Name Game or Quiz 3 before the test.) - Of the 211, 14 did not enter their own student number correctly. - Of the 211, 5 did not enter their own name or their own student number correctly, so the test couldn't be marked. I had to fix those sheets for you so that you could get some marks. - Of the 211, 17 did not put their name on their question sheet. I had to fix those for you, so that you could get your question sheet back for the bonus assignment. - Of the 211, 36 (17%) got question #45 wrong even though the answer was given in the **Test Instructions** printed at the start of the test. (24 people used the same, wrong, answer as the practice test.) - Dozens of students got their lab section wrong on the question sheet. See the **Prerequisites** in [Assignment #06 HTML] if you were one of them. - Five people scored 100% on the test. Congratulations! - **Read All The Words** ! The 211 class scores: 100 100 100 100 100 97.8 97.8 97.8 97.8 97.8 97.8 97.8 97.8 97.8 97.8 97.8 97.8 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 94.6 94.6 94.6 94.6 93.3 93.3 93.3 92.4 91.1 91.1 91.1 91.1 91.1 91.1 91.1 90.5 90.5 88.9 88.9 88.9 88.9 88.9 88.9 88 86.7 86.7 86.7 86.7 86.7 86.7 84.4 84.4 84.4 84.4 84.4 84.1 82.2 81.4 81.4 81.4 80 80 80 80 80 80 80 79.8 77.8 77.8 77.8 77.8 77.8 77.8 77.8 77.8 77.8 77.6 77 75.6 75.6 75.6 75.6 75.6 75.6 74.7 73.3 73.3 73.3 73.3 72.6 71.1 71.1 71.1 71.1 71.1 71.1 70.4 68.9 68.9 68.9 68.9 68.9 68.9 68.3 66.7 66.7 66.7 66.7 66 65.3 64.4 64.4 64.4 64.4 64.4 64.4 63.4 62.5 62.2 62.2 62.2 62.2 61.6 61 60 60 60 60 60 59.8 58.2 57.8 57.8 57.8 57.8 57.8 57.8 57.2 56.5 56 56 56 55.6 55.6 55.6 55.6 55.6 55.6 53.9 53.4 53.3 53.3 53.3 53.3 51.7 51.1 51.1 51.1 51.1 51.1 50.6 49.6 48.9 48.9 48.6 46.7 44 42.2 42.2 42.2 42.2 42.2 42.2 42.2 41.8 41.4 41.4 40.1 40 39.6 37.8 36.6 35.2 34.8 34.8 33.3 33.3 33.3 32.5 31.1 29.6 26.7 26.7 24.6 23.5 23 22 17 - You can see the class errors in [Midterm Test #1 PDF]. Please **Read All The Words**! Notes from the Classroom ======================== - **Take notes in class!** Keep a pad open on your desk. - This week, we learn about the Unix/Linux file system. - You will need to learn a text editor. I recommend [The VI (VIM) Text Editor]. Commands Used ------------- > Keep a notebook with a [List of Commands] in it. > > - You need to write down yourself what each command *does*. > - Check the updated list of commands each week. > - I will check for this list in your lab periods. > - Bring your notes to class! Stop wasting time looking up commands. - 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! BONUS Assignment #06 improves your Midterm #1 mark ================================================== Bonus (optional) [Assignment #06 HTML] may be done after you get your marks email and question sheet back for Midterm #1. You can use this bonus work to optionally improve your mark on the first midterm test. See the assignment for details. 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. Who is using the VIM editor? ============================ This page may take a minute or two to load; be patient: [Who is using the VIM editor?] 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]. SSH and HTTP Attacks on the CLS =============================== You are not paranoid if they really are out to get you! See the [Week 03 Notes HTML] for command pipelines to count the ongoing attacks on the CLS. Locked out of the CLS ===================== When you are locked out, [follow the directions] in the notes to get your IP address re-enabled. ![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 [File System]: 450_file_system.html [Hard links]: 455_links_and_inodes.html [Disk Usage]: 457_disk_usage.html [Symbolic Links]: 460_symbolic_links.html [Permissions]: 500_permissions.html [List of Commands]: 900_unix_command_list.html [Video Tutorials on Lynda.com]: 910_lynda_index.html [Linux and Sysadmin News in the World]: 950_linux_world.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 [Assignment #05 HTML]: assignment05.html [Shell GLOB patterns]: 190_glob_patterns.html [Shell I/O Redirection]: 200_redirection.html [Worksheet #04 HTML]: worksheet04.html [Worksheet #05 HTML]: worksheet05.html [Assignment #07 HTML]: assignment07.html [The VI (VIM) Text Editor]: 300_vi_text_editor.html [Assignment #04 HTML]: assignment04.html [Assignment #06 HTML]: assignment06.html [Finding Files]: 180_finding_files.html [Assignment #08 HTML]: assignment08.html [Course Introduction: Install Libre Office]: 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 [Assignment #09 HTML]: assignment09.html [Worksheet #08 PDF]: worksheet08.pdf [Worksheet #08 HTML]: worksheet08.html [Bring your favourite marker to your test]: data/sniff_markers.jpg "Bring your favourite marker to your test" [Quizzes and Tests]: 000_quizzes_and_tests.html [Brightspace CST8207]: https://brightspace.algonquincollege.com/d2l/home/117776 [Test Instructions]: 000_test_instructions.html [Midterm Test #1 PDF]: midterm1_18f.pdf [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 [Who is using the VIM editor?]: http://cst8207.idallen.ca/vim18f.cgi [Course Introduction]: 050_course_introduction.html [Week 03 Notes HTML]: week03notes.html [follow the directions]: 070_course_linux_server.html#getting-locked-out-of-the-server [Take Notes in Class]: data/remember.jpg "Take Notes in Class" [Pandoc Markdown]: http://johnmacfarlane.net/pandoc/