CMPSC 60: Week 5 Discussion

Topics for Today Some Unix commands Unix shells

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)

Find (cont.) find ~ -size 0 -exec rm {} \; Delete all zero length files under your home dir find ~ -perm -006 -exec chmod o-rw {} \; change all files under your home dir that can be read and written by all users so that they cannot

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”

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

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

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

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

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

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)

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

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 = "\n%n@%M [%t] %~\n%h %

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

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

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