Unix commands

1. Basic UNIX Commands
note: in the following description, filename means the name of any file,
cmd means any UNIX command, and arg means a generic argument.
command flags meaning
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passwd change password
exit leave UNIX (log out)
logout same as exit
man cmd give the UNIX manual page for cmd, if it exists
apropos arg list all UNIX commands that deal with arg
control-z suspend current application and escape to UNIX
fg restore application from UNIX
(if you can't log out because you have stopped
jobs, you have suspended an application and not
restored it.)
control-c kill current application
doesn't work for all applications (like vi)
useful for ending infinite loops
ls list files (like dir in DOS)
-a show hidden files
-l long listing of files (shows owner, size, last
modification, etc.)
ls filename list the file with name filename
ls dirname list the contents of directory dirname
cp filename1 filename2 copy file with name filename1 to filename2,
overwriting filename2 if it already exists
mv filename1 filename2 change the name of filename1 to filename2
overwriting filename2 if it already exists
rm filename delete file with name filename
(don't delete it unless you never need it again!)
-i interactive mode (prompt before deleting)
-f force mode (no prompt)
cat filename show the contents of filename
more filename show the contents of filename one page at a time
cd dirname change directory to directory dirname
cd change directory to your home directory
cd ~ same as cd
cd .. change directory to parent directory
mkdir dirname create directory dirname
rmdir dirname delete directory dirname
(only works if dirname contains no files
or directories)
pwd show current working directory
mv dirname1 dirname2 if dirname2 does not exist, change the name of
dirname1 to dirname2
if dirname2 does exist and does not contain a file
or subdirectory called dirname1, make dirname1
a subdirectory of dirname2
otherwise, return an error message
mv filename dirname move filename into directory dirname, overwriting
any file called filename already in dirname