1. CMPSC 60: Week 5 Discussion

2. Topics for Today
Some Unix commands
Unix shells

3. Find Recursively search for files find . -name “*.txt”
–list all files ending with “.txt” under the current dir
find ~ -name ‘*.txt’ -maxdepth 2
Find files ending with .txt within home dir up to 2 levels deep
find / -type d -user cshiflet
find all directories on the server owned by cshiflet
find ~ -mtime -7
find files under your home modified in the last 7 days (week)

4. Find (cont.) find ~ -size 0 -exec rm {} \;
Delete all zero length files under your home dir
find ~ -perm exec chmod o-rw {} \;
change all files under your home dir that can be read and written by all users so that they cannot

5. Grep search multiple files for a pattern grep text *
print the lines of any files that have “text” in them
grep -r sometext *
same as before, searching recursively
grep -l sometext *
print only the filenames of files with “sometext”

6. More Grep grep -n ‘//’ *.cpp grep -v text file grep -i text *
print the lines from all .cpp files that have a ‘//’ in them, and print the line number it was found on
grep -v text file
print all the lines of file that do not have “text” in them
grep -i text *
print the lines of all files with “text” in them, insensitive to case

7. Tar – Tape ARchive Copy files to or from an archive -x to extract
-t to test (list contents)
-c to create
-v to be verbose, print out what it’s doing
-f filename -- specifies input/output archive
-z -- gzip/gunzip the archive
-j -- bzip2/bunzip2 the archive

8. Tar examples tar -tzvf some.tar.gz tar -xzf some.tar.gz
List the files in some.tar.gz
tar -xzf some.tar.gz
Extract the files in some.tar.gz to the current dir
tar -czf out.tar.gz indir/
Compress the dir “indir” and all files in it into out.tar.gz

9. Unix Shells
Program that launches at login and allows you to enter commands
Examples:
CSH / TCSH
BASH SH
ZSH… and more

10. CSH - Manipulating Variables
env - List all environment variables
set - Set a normal variable
set class = cs60
setenv - Set an environment variable for the life of the shell (i.e. until you logout)
setenv PATH ${PATH}:/my/path/dir

11. CSH - Important Env Variables
PATH - Directories to search when executing a program
HOME - Full path of your home directory
SHELL - Full path/name of your shell
HOSTNAME - Host the shell is running on
USER - User who invoked the shell (YOU)

12. CSH - Important Normal Variables
prompt - Defines the prompt displayed
set prompt=“%M:%~%”
New prompt: host:~/current%
set prompt=“[%t] %M:%~%”
New prompt: [6:35pm] host:~/current%
Other prompt variables can be found by in the tcsh man page
history - Number of history commands stored
set history=100

13. More prompt fun %M – the machine you’re logged into
%~ – your current directory
%t – the current time
%n – your user name
%h – the current history event number
set prompt = [%t] %~\n%h %

14. CSH - Configuration Files
~/.cshrc - Run whenever CSH is started
~/.login - Run when you login with CSH
~/.logout - Run when you logout

15. CSH - ~/.cshrc Used to setup initial: PATH prompt aliases
User defined variables
Anything else you want every time you start CSH

16. CSH - ~/.login
Put commands here that you only want execute when you first login