QUICK UNIX REFERENCE
________________________________________________________________________

Files and Directories                      
_____________________
ls         = list files in directory
pwd        = your present working directory
cd         = change directory
rm         = remove file(s)
mv         = move file(s)
cp         = copy file(s)
mkdir      = make a new directory under this one
rmdir	   = remove an empty directory
chmod	   = change permissions for reading, writing, or executing files
more	   = page through a file
tail       = see the final lines of a file
sort       = sort the lines in a file in some order
diff       = compare two files and show the differences
grep       = look for a pattern in a file
tar        = make an archive file or extract files from an archive

Important Software
__________________
firefox    = start web browser (best currently in UNIX)
konqueror  = start a Windows-type file manager for copying, etc.
nano <file>= start a text editor (open and edit a file)
pine       = start an e-mail tool

cl         = run IRAF (run this command from your IRAF directory)
!<command> = run UNIX command within IRAF

Disk Usage
__________
du	   = how much disk space is this directory taking up
df         = how much of the disk is full

Remote      
______      
ssh        = login to another computer using a Secure Shell
scp        = copy files to another computer in a secure way
sftp       = "put" or "get" files on another computer in a secure way
ping       = check to see whether another computer is alive and well

System and Processes                          
____________________
top        = show the programs using the most CPU
ps         = report the status of an executing programs
kill -9    = kill an executing program (without mercy!)
nice       = run a program at lower priority (i.e. don't hog the computer's CPU)
alias      = set up an alternate name for a command (e.g. alias rm 'rm -i' )
fg         = bring to foreground

Printing                
________                
lpr        = print file (e.g. "lpr -Pps256" for the computer room)
lpq        = check status of print jobs
lprm       = remove a print job from the queue

Special Characters
__________________
~          = home directory
.          = current directory
..         = up one directory level
*          = wildcard of any length
?          = wildcard of one character
Tab        = complete the command or file name
>          = redirect output into a file
>>         = append output at end of an exisiting  file
<          = use a file as input rather than keyboard
|          = "pipe" = use the output of one command as input into another
&          = run in the background

<Control> (Ctrl) commands
_________________________
^c         = kill a program while it is running
^z         = put in background ( ^  means the <control> key)
^s         = suspend output  ( ^  means the <control> key)
^q         = restart output
^a         = go to start of line
^e         = go to end of line
^k         = kill a line

Programming & Executing                       
_______________________                       
f77 or g77 = compile a Fortan program   
cc  or gcc = compile a C program         

Miscellaneous
__________________________
man        = see documentation for a Unix command
wc         = tells the number of words or lines in a file
passwd	   = change password
which      = tells where the executable file for a program resides
gzip       = compresses file (creates .gz file)
gunzip     = uncompresses .gz file
gv         = view a .ps or .pdf file
acroread   = view a .pdf file