2>&1
, awk fields $1 $NFFall 2018 - September to December 2018 - Updated 2018-10-01 01:33 EDT
awk
– extracting fields from input lines and columns from input files using awk
and $1
and $NF
USER HOME SHELL PATH TERM $$
find
using “wildcard” (GLOB) patterns - same as shell GLOBvi/vim, nano
head, tail
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.
PS1 find mkdir mv cp rm touch file
PS1
prompt every time you log in to the CLS.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. 2. Worksheets. 3. Assignment.
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 #02 and #03 require you to have read File System and Pathnames:
PS1, cd, find, less, ls, man, mkdir, passwd, pwd, rmdir
PS1
prompt every time you log in to the CLS.cat, clear, cp, find, fgrep, history, less, man, mv, rm, sleep, touch
Worksheets #04 and #05 require you to have read Shell GLOB patterns and Shell I/O Redirection:
alias, sum, unalias
date, head, nl, tail, tr, wc
Worksheet #06 is for the optional VIM Bonus Assignment (extra credit):
vim
vimtutor
program on the CLS.Worksheets prepare you for the upcoming assignments.
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.
Tests take place in your one-hour lecture class, not in your lab period. You must write the test in the lecture class in which you are registered.
Take notes in class! Keep a pad open on your desk.
This week, we learn about I/O redirection and pipes.
I recommend that you learn the VIM text editor.
How do you know a pathname exists? What command can you use to verify that a pathname you type actually exists?
Remember to set your prompt (PS1=
) every time you log in to the CLS. It only takes three keystrokes to recall and execute the command line.
If you think the Course Linux Server (CLS) is down, try this URL: http://cst8207.idallen.ca/montage18f.cgi If it works, you know the CLS is working. If the URL works and you don’t get a login:
prompt using PuTTY, then your IP is probably locked out of the CLS.
You will see lots of these: Rewrite each pathname as a simplified absolute pathname with no .
or ..
references:
/home/me/../you/../../etc/../home/me/../you/../me/../foo
/home/me/../you/../../etc/../home/me/../you/../me/../..
/usr/./bin/../lib/../../etc/../usr/./lib/../bin/./bar
/usr/./bin/../lib/../../etc/../usr/./lib/../bin/..
/../../var/./a/../../var/b/../../etc/./bar/../foo
/../../var/./a/../../var/b/../../etc/./bar/..
These questions and the answers are part of Practice Test #1 in Practice Tests and Answers. Look for questions starting with “Simplify this pathname”.
See last week’s note about drawing file system diagrams: Week 03 Notes HTML
Students will have their CLS accounts disabled if they have not changed their default password. (I do not want people breaking into my machine because of you.)
See my online timetable for how to make an office appointment to see me if you want your account back.
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.
-name
arguments to find
find
GLOB patterns to hide them from the shell!ls -d
: The man page says “list directories themselves, not their contents”. It doesn’t say “list only directories;, do not list files”. If you give a file and a directory to ls -l -d
, you will get the file name and the directory name in the output. If you give a file and a directory to ls
without -d
, you will get the file name and the contents of the directory (not the directory name itself) in the output. See the difference? The -d
shows the directory itself, not what is in the directory.Your elected Level 1 student class representatives are:
grif0218
bars0026
You may ask your representatives to bring up issues with your professor or with the department chair.
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.
See your Networking course announcements.
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.
When you are locked out, follow the directions in the notes to get your IP address re-enabled.