UNIX On-line Help

Departments of Mathematics & Statistics, University of South Carolina

Here is a long list of UNIX commands with their short descriptions. You can learn more about them by typing man filename in one of your xterm window, or by starting the program xman.
a2ps
formats an ASCII file for printing on a postscript printer
adb
general-purpose debugger
addbib
create or extend a bibliographic database
apropos
locate commands by keyword lookup
ar
create library archives, and add or extract files
arch
display the architecture of the current host
as
Sun-1, Sun-2 and Sun-3, Sun-4 and Sun386i assemblers
at, batch
execute a command or script at a specified time
atq
display the queue of jobs to be run at specified times
atrm
remove jobs spooled by at or batch
autool
audio play/record tool compatible with audiotool
awk
pattern scanning and processing language
banner
display a string in large letters
basename, dirname
display portions of pathnames and filenames
bc
arbitrary-precision arithmetic language
biff
give notice of incoming mail messages
cal
display a calendar
calendar
a simple reminder service
cat
concatenate and display
cb
a simple C program beautifier
cc
C compiler
cd
change working directory
cflow
generate a flow graph for a C program
checknr
check nroff and troff input files; report possible errors
chgrp
change the group ownership of a file
chkey
create or change encryption key
chmod
change the permissions mode of a file
clear
clear the terminal screen
click
enable or disable the keyboard's keystroke click
clock
display the time in an icon or window
cmp
perform a byte-by-byte comparison of two files
col
filter reverse paper motions from nroff output for display on a terminal
colcrt
filter nroff output for a terminal lacking overstrike capability
coloredit
alter color map segment
colrm
remove characters from specified columns within each line
comm
display lines in common, and lines not in common, between two sorted lists
compress, uncompress, zcat
compress or expand files, display expanded contents
cp
copy files
cpp
the C language preprocessor
crontab
install, edit, remove or list a user's crontab file
csh
a shell (command interpreter) with a C-like syntax and advanced interactive features
alias, bg, break, breaksw, case, continue, default, dirs, else, end, endif, endsw, eval, exec, exit, fg, foreach, glob, goto, hashstat, history, if, jobs, label, limit, logout, notify, onintr, popd, pushd, rehash, repeat, set, setenv, shift, source, stop, suspend, switch, then, umask, unalias, unhash, unlimit, unset, unsetenv, while
C shell built-in commands, see csh
csplit
split a file with respect to a given context
ctags
create a tags file for use with ex and vi
ctrace
generate a C program execution trace
cut
remove selected fields from each line of a file
cxref
generate a C program cross-reference
date
display or set the date
dbx
source-level debugger
dc
desk calculator
dd
convert and copy files with various data formats
deroff
remove nroff, troff, tbl and eqn constructs
desktop
switch the window system to be invoked upon login
df
report free disk space on file systems
diff
display line-by-line differences between pairs of text files
diff3
display line-by-line differences between 3 files
diffmk
mark differences between versions of a troff input file
dircmp
compare directories
dis
object code disassembler for COFF
domainname
set or display name of the current NIS domain
dos2unix
convert text file from DOS format to ISO format
du
display the number of disk blocks used per directory or file
echo
echo arguments to the standard output
ed, red
basic line editor
eject
eject media device from drive
env
obtain or alter environment variables for command execution
eqn, neqn, checkeq
typeset mathematics
error
categorize compiler error messages, insert at responsible source file lines
ex, edit, e
line editor
expand, unexpand
expand TAB characters to SPACE characters, and vice versa
expr
evaluate arguments as a logical, arithmetic, or string expression
file
determine the type of a file by examining its contents
find
find files by name, or by other characteristics
finger
display information about users
fmt, fmt_mail
simple text and mail-message formatters
fold
fold long lines for display on an output device of a given width
fontedit
a vfont screen-font editor
foption
determine available floating-point code generation options
from
display the sender and date of newly-arrived mail messages
ftp
file transfer program
gcore
get core images of running processes
getopt
parse command options in shell scripts
getopts, getoptcvt
parse command options in shell scripts
gprof
display call-graph profile data
graph
draw a graph
grep, egrep, fgrep
search a file for a string or regular expression
groups
display a user's group memberships
head
display first few lines of specified files
help_open
use help_viewer to open a file
hostid
print the numeric identifier of the current host
hostname
set or print name of current host system
id
print the user name and ID, and group name and ID
indent
indent and format a C program source file
indxbib
create an inverted index to a bibliographic database
inline
in-line procedure call expander
install
install files
intro
introduction to commands
ipcrm
remove a message queue, semaphore set, or shared memory ID
ipcs
report interprocess communication facilities status
joe
Joe's Own Editor
join
relational database operator
kill
send a signal to a process, or terminate a process
last
indicate last logins by user or terminal
lastcomm
show the last commands executed, in reverse order
ld, ld.so
link editor, dynamic link editor
ldd
list dynamic dependencies
leave
remind you when you have to leave
lex
lexical analysis program generator
line
read one line
lint
a C program verifier
ln
make hard or symbolic links to files
logger
add entries to the system log
login
log in to the system
logname
get the name by which you logged in
look
find words in the system dictionary or lines in a sorted list
lookbib
find references in a bibliographic database
lorder
find an ordering relation for an object library
lp, cancel
send/cancel requests to a printer
lpq
display the queue of printer jobs
lpr
send a job to the printer
lprm
remove jobs from the printer queue
lpstat
display the printer status information
lptest
generate lineprinter ripple pattern
ls
list the contents of a directory
lsw
list TFS whiteout entries
m4
macro language processor
mach
display the processor type of the current host
mail, Mail
read or send mail messages
make
maintain, update, and regenerate related programs and files
man
display reference manual pages; find reference pages by keyword
mesg
permit or deny messages on the terminal
mkdir
make a directory
mkstr
create an error message file by massaging C source files
more, page
browse or page through a text file
mset
retrieve ASCII to IBM 3270 keyboard map
mv
move or rename files
nawk
pattern scanning and processing language
newgrp
log in to a new group
nice
run a command at low priority
nl
line numbering filter
nm
print symbol name list
nn
efficient net news interface (No News is good news)
nncheck
check for unread articles
nngoback
make news articles unread on a day-by-day basis (nn)
nngrab
news retrieval by keyword (nn)
nngrep
grep for news group names (nn)
nnpost
post news articles (nn)
nntidy
tidy your personal .newsrc file
nnusage
display nn usage statistics
nohup
run a command immune to hangups and quits
npasswd
change login password
nroff
format documents for display or line-printer
objdump
dump selected parts of a COFF object file
od
octal, decimal, hexadecimal, and ASCII dump
on
execute a command on a remote system, but with the local environment
pack, pcat, unpack
compress and expand files
pagesize
display the size of a page of memory
passwd, chfn, chsh
change local or NIS password information
paste
join corresponding lines of several files, or subsequent lines of one file
perfmeter
display system performance values in a meter or strip chart
pg
page through a file on a soft-copy terminal
plot, aedplot, bgplot, crtplot, dumbplot, gigiplot, hpplot, implot, t300, t300s, t4013, t450, tek
graphics filters for various plotters
pr
prepare file(s) for printing, perhaps in multiple columns
printenv
display environment variables currently set
prof
display profile data
ps
display the status of current processes
ptx
generate a permuted index
pwd
display the pathname of the current working directory
quota
display a user's disk quota and usage
ranlib
convert archives to random libraries
rasfilter8to1
convert an 8-bit deep rasterfile to a 1-bit deep rasterfile
rastrepl
magnify a raster image by a factor of two
rcp
remote file copy
rdist
remote file distribution program
refer
expand and insert references from a bibliographic database
resize
utility to set TERMCAP and terminal settings to current window size
rev
reverse the order of characters in each line
rlogin
remote login
rm, rmdir
remove (unlink) files or directories
roffbib
format and print a bibliographic database
rpcgen
RPC protocol compiler
rsh
remote shell
screenblank
turn off the screen when the mouse and keyboard are idle
screendump
dump a frame-buffer image to a file
screenload
load a frame-buffer image from a file
script
make typescript of a terminal session
sdiff
contrast two text files by displaying them side-by-side
sed
stream editor
sh
shell, the standard UNIX system command interpreter and command-level language
size
display the size of an object file
sleep
suspend execution for a specified interval
sort
sort and collate lines
sortbib
sort a bibliographic database
spell, hashmake, spelling, hashcheck
report spelling errors
spline
interpolate smooth curve
split
split a file into pieces
strings
find printable strings in an object file or binary
strip
remove symbols and relocation bits from an object file
stty
set or alter the options for a terminal
sum
calculate a checksum for a file
symorder
rearrange a list of symbols
sysex
start the system exerciser
syswait
execute a command, suspending termination until user input
tabs
set tab stops on a terminal
tail
display the last part of a file
talk
talk to another user
tar
create tape archives, and add or extract files
tbl
format tables for nroff or troff
tcov
construct test coverage analysis and statement-by-statement profile
tee
replicate the standard output
telnet
user interface to a remote system using the TELNET protocol
test
return true or false according to a conditional expression
tftp
trivial file transfer program
time
time a command
tn3270
full-screen remote login to IBM VM/CMS
touch
update the access and modification times of a file
tput
initialize a terminal or query the terminfo database
tr
translate characters
trace
trace system calls and signals
troff
typeset or format documents
true, false
provide truth values
tset, reset
establish or restore terminal characteristics
tsort
topological sort
tty
display the name of the terminal
ul
do underlining
uname
display the name of the current system
unifdef
resolve and remove ifdef'ed lines from cpp input
uniq
remove or report adjacent duplicate lines
units
conversion program
unix2dos
convert text file from ISO format to DOS format
unwhiteout
remove a TFS whiteout entry
users
display a compact list of users logged in
vacation
reply to mail automatically
vfontinfo
inspect and print out information about fonts
vgrind
grind nice program listings
vi, view, vedit
visual display editor based on ex(1)
vplot
plot graphics for a Versatec printer
vswap
convert a foreign font file
vtroff
troff to a raster plotter
vwidth
make a troff width table for a font
w
who is logged in, and what are they doing
wait
wait for a process to finish
wc
display a count of lines, words and characters
what
extract SCCS version information from a file
whatis
display a one-line summary about a keyword
whereis
locate the binary, source, and manual page files for a command
which
locate a command; display its pathname or alias
who
who is logged in on the system
whoami
display the effective current username
whois
TCP/IP Internet user name directory service
write
write a message to another user
xargs
construct the arguments list(s) and execute a command
xstr
extract strings from C programs to implement shared strings
yacc
yet another compiler-compiler: parsing program generator
yes
be repetitively affirmative