Summary of utilities

Utility Description
adduser creates new user
alias define or display aliases
ar maintain a library archive
at execute commands at a specified time
awk pattern scanning and processing language
basename display non-directory part of filename
batch execute commands when system load permits
bc calculator
bg run a job to the background
break exit from for, while or until loop
cat concatenate and print files to standard output
cd change working directory
chgrp change file group ownership
chmod change file access privileges
chown change file ownership
cksum file checksum utility
cmp compare two files
comm select/reject lines common to two files
command execute a simple command
compress reduces file to compressed form
continue continue for, while or until loop
cp copy files
crontab schedule periodic background work
csplit split a file according to context
ctags create a 'tags' file
cut select columns or fields from each line of a file
date display current time and date
dd convert file format
df display free disk space
diff show differences between two files
dirname display directory part of a pathname
du display file space usage
echo write arguments to standard output
ed basic text editor
env set environment for a command
eval construct command by concatenating arguments
exec execute command by replacing shell process
exit cause the shell to exit
expand replace tabs by spaces
export set export attribute for a variable
expr evaluate an arithmetic expression
ex text editor (see vi)
false returns 'false' value, exit status 1
fc process command history list
fdisk modifies disk partition table
fg run a job to the foreground
file describe file contents
find find files
fold fold lines
getconf get configuration variables
getopts parse options for a utility
grep select lines matching regular expression
gunzip uncompresses gzip file
gzip reduces file to compressed form
head show the first few lines of a file
id display information about a user's identity
jobs list the jobs in the current session
join relational database operator
kill send a signal to a process
ln link files
locale display information about the 'locale'
localedef define the 'locale'
logger log message for the system administrator
logname display your login user name
lp send files to a printer
ls list files (directory contents)
mailx process electronic mail messages
make maintain and update groups of programs
man display manual pages
mesg allow or deny messages on your terminal
mkdir create new directories
mkfifo create a FIFO file
more 'pager'
mv move files
newgrp change your current group-id
nice run a command with changed priority
nm display name list of an object file
nohup run a command immune to hangups
od dump files in various formats
passwd change login password
paste merge corresponding lines of text files
patch apply changes to files
pathchk check pathname is valid
pax file archiver and format translator
perl 'Practical Extraction and Report Language'
pr a very basic formatter for text files
printf write formatted output
ps display information about processes
pwd display working directory
read read a line from standard input
readonly set read-only attribute for variables
renice change the priority of a running process
return return from a function
rm remove a file
rmdir remove empty directories
sed stream editor
set set options and positional parameters
sh the shell
shift shift positional parameters
shutdown close down processes and shut down machine
sleep suspend execution for a time interval
sort sort or merge text files
split split a file into pieces
ssh secure shell for remote login
strings display printable strings in a file
strip remove unnecessary data from executable files
stty set terminal options
tabs reset the tab positions
tail show the last few lines of a file
talk talk to another user
tar file and directory archive tool
tee duplicate standard input
test evaluate expression
time display execution time for a command
touch change last modification time of a file
tput change terminal characteristics
tr translate characters
trap intercept a signal
true returns 'true' value, exit status 0
tty display the terminal name
umask change access privileges when files are created
unalias remove alias definition
uname display the system name
unexpand replace spaces by tabs
uniq filter out repeated lines
unset unset options and positional parameters
useradd creates new user
userdel removes a user
uudecode decode a file which was coded with uuencode
uuencode encode a binary file
vi full-screen text editor
wait suspend process until completion of another process
wc word, line and byte count
who list who is using the system
write write a message on another user's terminal
ypmatch prints values from Network Information System
xargs construct argument list and execute command