Linux Commands

Command	Description
adduser	Add a new user
arch	Print machine architecture
awk	Find and Replace text within file(s)
bc	An arbitrary precision calculator language
cal	Display a calendar
cat	Concatenate files and print on the standard output
chdir	Change working directory
chgrp	Change the group ownership of files
chkconfig	Tool for maintaining the /etc/rc[0-6].d directory hierarchy
chmod	Change the access permissions of files and directories
chown	Change the user and group ownership of files
chroot	Change root directory
cksum	Print CRC checksum and byte counts
clear	Clear terminal screen
cmp	Compare two files
comm	Compare two sorted files line by line
cp	Copy one or more files to another location
cron	Daemon to execute scheduled commands
crontab	Schedule a command to run at a later time
csplit	Split a file into context-determined pieces
cut	Divide a file into several parts
date	Display or change the date & time
dc	Desk Calculator
dd	Data Dump - Convert and copy a file
df	Display free disk space
diff	Display the differences between two files
diff3	Show differences among three files
dir	Briefly list directory contents
dircolors	Colour setup for `ls'
dirname	Convert a full pathname to just a path
du	Estimate file space usage
echo	Display message on screen
ed	A line-oriented text editor (edlin)
egrep	Search file(s) for lines that match an extended expression
eject	Eject CD-ROM
env	Display, set, or remove environment variables
expand	Convert tabs to spaces
expr	Evaluate expressions
factor	Print prime factors
false	Do nothing, unsuccessfully
fdformat	Low-level format a floppy disk
fdisk	Partition table manipulator for Linux
fgrep	Search file(s) for lines that match a fixed string
find	Search for files that meet a desired criteria
fmt	Reformat paragraph text
fold	Wrap text to fit a specified width
format	Format disks or tapes
free	Display memory usage
fsck	Filesystem consistency check and repair
gawk	Find and Replace text within file(s)
grep	Search file(s) for lines that match a given pattern
groups	Print group names a user is in
gzip	Compress or decompress named file(s)
head	Output the first part of file(s)
hostname	Print or set system name
id	Print user and group id's
info	Help info
install	Copy files and set attributes
join	Join lines on a common field
kill	Stop a process from running
less	Display output one screen at a time
ln	Make links between files
locate	Find files
logname	Print current login name
lpc	Line printer control program
lpr	Off line print
lprm	Remove jobs from the print queue
ls	List information about file(s)
man	Help manual
mkdir	Create new folder(s)
mkfifo	Make FIFOs (named pipes)
mknod	Make block or character special files
more	Display output one screen at a time
mount	Mount a file system
mv	Move or rename files or directories
nice	Set the priority of a command or job
nl	Number lines and write files
nohup	Run a command immune to hangups
passwd	Modify a user password
paste	Merge lines of files
pathchk	Check file name portability
pr	Convert text files for printing
printcap	Printer capability database
printenv	Print environment variables
printf	Format and print data
ps	Process status
pwd	Print Working Directory
quota	Display disk usage and limits
quotacheck	Scan a file system for disk usage
quotactl	Set disk quotas
ram	ram disk device
rcp	Copy files between two machines
rm	Remove files
rmdir	Remove folder(s)
rpm	Remote Package Manager
rsync	Remote file copy (Synchronize file trees)
screen	Terminal window manager
sdiff	Merge two files interactively
sed	Stream Editor
select	Accept keyboard input
seq	Print numeric sequences
shutdown	Shutdown or restart linux
sleep	Delay for a specified time
sort	Sort text files
split	Split a file into fixed-size pieces
su	Substitute user identity
sum	Print a checksum for a file
symlink	Make a new name for a file
sync	Synchronize data on disk with memory
tac	Concatenate and write files in reverse
tail	Output the last part of files
tar	Tape Archiver
tee	Redirect output to multiple files
test	Evaluate a conditional expression
time	Measure Program Resource Use
touch	Change file timestamps
top	List processes running on the system
traceroute	Trace Route to Host
tr	Translate, squeeze, and/or delete characters
true	Do nothing, successfully
tsort	Topological sort
tty	Print filename of terminal on stdin
umount	Unmount a device
uname	Print system information
unexpand	Convert spaces to tabs
uniq	Uniquify files
units	Convert units from one scale to another
unshar	Unpack shell archive scripts
useradd	Create new user account
usermod	Modify user account
users	List users currently logged in
uuencode	Encode a binary file
uudecode	Decode a file created by uuencode
vdir	Verbosely list directory contents (`ls -l -b')
watch	Execute/display a program periodically
wc	Print byte, word, and line counts
whereis	Report all known instances of a command
which	Locate a program file in the user's path
who	Print all usernames currently logged in
whoami	Print the current user id and name (`id -un')
xargs	Execute utility, passing constructed argument list(s)
yes	Print a string until interrupted