Linux Shell Commands - Command Summary Flashcards
a2p
Creates a Perl script from an awk script.
ac
Prints statistics about user connection time.
access
A system function which checks real user’s permissions to access a file.
addgroup
Adds a new group to the system.
adduser
Adds a new user to the system.
agrep
Version of the grep utility which also matches approximate patterns.
alias
Creates another name for a command or command string.
apropos
Searches the manual pages for a keyword or regular expression.
apt-cache
Queries the APT software package cache.
apt-get
Command line tool for working with APT software packages.
aptitude
Text-based front-end for the APT package management system.
ar
Creates, modifies, and extracts from archives.
arch
Displays the architecture of the current host.
arp
Manipulate the system ARP cache.
as
An assembler.
aspell
Interactive spell checker.
at
Command scheduler.
awk
Awk script processing program.
basename
Deletes any specified prefix from a string.
bash
Command Bourne interpreter
bc
Calculator.
bdiff
Compare large files.
bfs
Editor for large files.
bg
Continues a program running in the background.
biff
Enable and disable incoming mail notifications.
break
Break out of while, for, foreach, or until loop.
bs
Battleship game.
bye
Alias often used for the exit command.
cal
Calendar.
calendar
Display appointments and reminders.
cancel
Cancels a print job.
cat
View or modify a file.
cc
C compiler.
cd
Change directory.
cfdisk
A more user-friendly version of the fdisk disk partitioning utility.
chdir
Change directory.
checkeq
Language processors to assist in describing equations.
checknr
Check nroff and troff files for any errors.
chfn
Modify your own information or if superuser or root modify another users information.
chgrp
Change a groups access to a file or directory.
chkey
Change the secure RPC key pair.
chmod
Change the permission of a file.
chown
Change the ownership of a file.
chroot
Run a command or shell from another directory, and treats that directory as root.
chsh
Change login shell.
cksum
Display and calculate a CRC for files.
clear
Clears screen.
cmp
Compare files.
col
Reverse line-feeds filter.
comm
Compare files and select or reject lines that are common.
compress
Compress files on a computer.
continue
Break out of while, for, foreach, or until loop.
cp
Copy files.
cpio
Creates archived CPIO files.
crontab
Create and list files that you want to run on a regular schedule.
crypt
Function used to encrypt passwords.
csh
Execute the C shell command interpreter
csplit
Split files based on context.
ctags
Create a tag file for use with ex and vi.
cu
Calls or connects to another Unix system, terminal or non-Unix system.
curl
Transfer a URL.
cut
Cut out selected fields of each line of a file.
date
Tells you the date and time in Unix.
dc
An arbitrary precision arithmetic package.
dd
Convert and copy a file.
delgroup
Remove a group from the system.
deluser
Remove a user from the system.
depmod
Generates a list of kernel module dependences, modules.dep, and associated map files.
deroff
Removes nroff/troff, tbl, and eqn constructs.
df
Display the available disk space for each mount.
dhclient
Dynamic Host Configuration Protocol Client.
diff
Displays two files and prints the lines that are different.
dig
DNS lookup utility.
dircmp
Lists the different files when comparing directories.
dirname
Deliver portions of path names.
dmesg
Print or control the kernel ring buffer.
dos2unix
Converts text files between DOS and Unix formats.
dpkg
Queries, installs, removes, and maintains Debian software packages and their dependencies.
dpost
Translates files created by troff into PostScript.
du
Tells you how much space a file occupies.
echo
Displays text after echo to the terminal.
ed
Line oriented file editor.
edit
Text editor.
egrep
Search a file for a pattern using full regular expressions.
eject
Ejects removable media.
elm
Program command used to send and receive e-mail.
emacs
Text editor.
enable
Enables and disables LP printers.
env
Displays environment variables.
eqn
Language processors to assist in describing equations.
ex
Line-editor mode of the vi text editor.
exit
Exit from a program, shell or log you out of a Unix network.
expand
Expand copies of files.
expr
Evaluate arguments as an expression.
fc
Lists, edits, or re-executes commands previously entered.
fdisk
A disk partioning utility.
fg
Continues a stopped job by running it in the foreground
fgrep
Search a file for a fixed-character string.
file
Tells you if the object you are looking at is a file or a directory.
find
Finds files within a directory hierarchy.
findsmb
List info about machines that respond to SMB name queries on a subnet.
finger
Lists information about the user.
fmt
Simple text formatters.
fold
Filter for folding lines.
for
Shell built-in functions to repeatedly execute action(s) for a selected number of times.
foreach
Shell built-in functions to repeatedly execute action(s) for a selected number of times.
free
Display amount of free and used memory in the system
fsck
Check and repair a Linux file system.
ftp
Enables ftp access to another terminal.
fuser
Identify processes using files or sockets.
gawk
Powerful pattern-matching and processing language.
getfacl
Display discretionary file information.
gethostname
System call to get the hostname of the current processor.
gpasswd
Administer /etc/group and /etc/gshadow.
gprof
The gprof utility produces an execution profile of a program.
grep
Finds text within a file.
groupadd
Creates a new group account.
groupdel
Enables a superuser or root to remove a group.
groupmod
Enables a superuser or root to modify a group.
gunzip
Expand compressed files.
gview
A programmer’s text editor.
gvim
A programmer’s text editor.
gzip
Compress files.
halt
Stop the computer.
hash
Remove internal hash tables.
hashstat
Evaluates the effectiveness of internal hash tables.
head
Displays the first ten lines of a file, unless otherwise stated.
help
Displays help for built-in shell commands.
history
Display the command history.
host
DNS lookup utility.
hostid
Prints the numeric identifier for the current host.
hostname
Set or print name of current host system.
id
Shows you the numeric user and group ID on BSD.
ifconfig
Sets up network interfaces.
ifdown
Take a network interface down.
ifup
Bring a network interface up.
info
Read Info documents.
init
Process control initialization.
iostat
Reports Central Processing Unit (CPU) statistics and input/output statistics for devices and partitions.
ip
Show and manipulate routing, devices, policy routing and tunnels.
isalist
Display the native instruction sets executable on this platform.
iwconfig
Configure a wireless network interface.
jobs
List the jobs currently running in the background.
join
Joins command forms together.
keylogin
Decrypt the user’s secret key.
kill
Cancels a job.
killall
Kills processes by name.
ksh
Korn shell command interpreter.
last
Displays a listing of the most recently logged-in users.
ld
Link-editor for object files.
ldd
List dynamic dependencies of executable files or shared objects.
less
Opposite of the more command.
lex
Generate programs for lexical tasks.
link
Calls the link function to create a link to a file.
ln
Creates a link to a file.
lo
Allows you to exit from a program, shell or log you out of a Unix network.
locate
List files in databases that match a pattern.
login
Signs into a new system.
logname
Returns users login name.
logout
Logs out of a system.
losetup
Sets up and controls loop devices.
lp
Prints a file on System V systems.
lpadmin
Configure the LP print service.
lpc
Line printer control program.
lpq
Lists the status of all the available printers.
lpr
Submits print requests.
lprm
Removes print requests from the print queue.
lpstat
Lists status of the LP print services.
ls
Lists the contents of a directory.
lsof
Lists open files.
lzcat
View compressed .lzma files.
lzma
Compress files to .lzma file.
mach
Display the processor of the current host.
One of the ways that allows you to read/send E-Mail.
mailcompat
Provide SunOS 4.x compatibility for the Solaris mailbox format.
mailx
Mail interactive message processing system.
make
Executes a list of shell commands associated with each target.
man
Display the documentation (manual page) of a given command.
merge
Performs a merge of the contents of three files.
mesg
Control if non-root users can send text messages to you.
mii-tool
View, manipulate media-independent interface status.
mkdir
Create a directory.
mkfs
Build a Linux file system, usually a hard disk partition.
mkswap
Sets up a Linux swap area.
modprobe
Adds and removes modules from the linux kernel.
more
Displays text one screen at a time.
mount
Creates a file systems and remote resources.
mt
Magnetic tape control.
mv
Renames a file or moves it from one directory to another directory.
myisamchk
Checks, repairs, optimises, or fetches information about a MySQL database.
mysql
An open-source relational database management system.
mysqldump
A tool for backing up or transferring mysql databases.
nc
TCP/IP swiss army knife.
neqn
Language processors to assist in describing equations.
netstat
Shows network status.
newalias
Install new elm aliases for user or system.
newform
Change the format of a text file.
newgrp
Log into a new group.
nice
Invokes a command with an altered scheduling priority.
niscat
Display NIS+ tables and objects.
nischmod
Change access rights on a NIS+ object.
nischown
Change the owner of a NIS+ object on a system running Solaris.
nischttl
Change the time to live value of a NIS+ object.
nisdefaults
Display NIS+ default values.
nisgrep
Utilities for searching NIS+ tables.
nismatch
Utilities for searching NIS+ tables.
nispasswd
Change NIS+ password information.
nistbladm
NIS+ table administration command.
nl
Numbers the lines in a file.
nmap
Network exploration tool and security port scanner.
nohup
Runs a command even if the session is disconnected or the user logs out.
nroff
Formats documents for display or line-printer.
nslookup
Queries a name server for a host or domain lookup.
od
Dump files in octal and other formats.
on
Execute a command on a remote system, but with the local environment.
onintr
Shell built-in functions to respond to (hardware) signals.
optisa
Determine which variant instruction set is optimal to use.
pack
Shrinks file into a compressed file.
pagesize
Display the size of a page of memory in bytes, as returned by getpagesize.
parted
A disk partition manipulation program.
partprobe
Informs the operating system about changes to the partition table.
passwd
Allows you to change your password.
paste
Merge corresponding or subsequent lines of files.
pax
Read/write and writes lists of the members of archive files and copy directory hierarchies.
pcat
Compresses file.
perl
Perl is a programming language optimized for scanning arbitrary text files, extracting information from those text files.
pg
Files perusal filters for CRTs.
pgrep
Examine the active processes on the system and reports the process IDs of the processes
pico
Simple and very easy to use text editor in the style of the Pine Composer.
pine
Command line program for Internet News and Email.
ping
Sends ICMP ECHO_REQUEST packets to network hosts.
pkill
Examine the active processes on the system and reports the process IDs of the processes
poweroff
Stop the computer.
pr
Formats a file to make it look better when printed.
priocntrl
Displays or sets scheduling parameters of processes.
printenv
Prints all or part of environment.
printf
Write formatted output.
ps
Reports the process status.
pstree
Displays processes in tree format.
pvs
Display the internal version information of dynamic objects within an ELF file.
pwd
Print the current working directory.
quit
Allows you to exit from a program, shell or log you out of a Unix network.
rcp
Copies files from one computer to another computer.
readlink
Prints the value of a symbolic link or canonical file name.
reboot
Stop the computer.
red
The “restricted” version of a line-oriented file editor.
rehash
Recomputes the internal hash table of the contents of directories listed in the path.
rename
Renames multiple files using a regular expression.
renice
Alters the priority of running processes.
repeat
Shell built-in functions to repeatedly execute action(s) for a selected number of times.
replace
A string-replacement utility.
rgview
A programmer’s text editor.
rgvim
A programmers text editor.
rlogin
Establish a remote connection from your terminal to a remote machine.
rm
Deletes a file without confirmation (by default).
rmdir
Deletes a directory.
rn
Reads newsgroups.
route
Show and manipulate the IP routing table.
rpcinfo
Report RPC information.
rsh
Runs a command on another computer.
rsync
Faster, flexible replacement for rcp.
rview
A programmers text editor.
rvim
A programmers text editor.
s2p
Convert a sed script into a Perl script.
sag
Graphically displays the system activity data stored in a binary data file by a previous sar run.
sar
Displays the activity for the CPU.
scp
Transfers files securely over a network connection.
screen
Screen manager with VT100/ANSI terminal emulation.
script
Records everything printed on your screen.
sdiff
Compares two files, side-by-side.
sed
Allows you to use pre-recorded commands to make changes to text.
sendmail
Sends mail over the Internet.
service
Runs a System V init script.
set
Set the value of an environment variable.
setenv
Set the value of an environment variable.
setfacl
Modify the Access Control List (ACL) for a file or files.
sethostname
System calls or set the hostname of the current processor.
sfdisk
A low-level disk partitioning program.
sftp
Secure file transfer program.
sh
Runs or processes jobs through the Bourne shell.
shred
Delete a file securely, first overwriting it to hide its contents.
shutdown
Turn off the computer immediately or at a specified time.
sleep
Waits a x amount of seconds.
slogin
OpenSSH SSH client (remote login program).
smbclient
An ftp-like client to access SMB/CIFS resources on servers.
sort
Sorts the lines in a text file.
spell
Looks through a text file and reports any words that it finds in the text file that are not in the dictionary.
split
Split a file into pieces.
startx
Starts an X Window System session.
stat
Display file or filesystem status.
stop
Control process execution.
strftime
Formats strings that represent the system date and time.
strip
Discard symbols from object files.
stty
Sets options for your terminal.
su
Become superuser or another user.
sudo
Executes any command as the superuser.
swapoff
Disables a Linux swap area.
swapon
Enables a Linux swap area.
sysinfo
Get and set system information strings.
sysklogd
Linux system logging utilities.
tabs
Set tabs on a terminal.
tail
Delivers the last part of the file.
talk
Talk with other logged in users.
tac
Concatenate and print files in reverse.
tar
Create tape archives and add or extract files.
tbl
Preprocessor for formatting tables for nroff or troff.
tcopy
Copy a magnetic tape.
tcpdump
Dump traffic on a network.
tcsh
A command-line shell similar to csh, with some additional features.
tee
Read from an input and write to a standard output or file.
telinit
Process control initialization.
telnet
Uses the telnet protocol to connect to another remote computer.
test
Check file types and compare values.
time
Used to time a simple command.
timex
The timex command times a command; reports process data and system activity.
todos
Converts text files between DOS and Unix formats.
top
Display Linux tasks.
touch
Change file access and modification time.
tput
Initialize a terminal or query terminfo database.
tr
Translate characters.
traceroute
Print the route packets take to network host.
trap
A function which “traps” signals and interrupts, and reacts to them.
tree
List the contents of a file hierarchy visually in a tree format.
troff
Typeset or format documents.
tty
Print the file name of the terminal connected to standard input.
ul
Reads the named filenames or terminal and does underlining.
umask
Get or set the file mode creation mask.
unalias
Remove an alias.
unhash
Remove internal hash table.
uname
Print name of current system.
uncompress
Uncompressed compressed files.
uniq
Report or filter out repeated lines in a file.
unlink
Call the unlink function to remove the specified file.
unlzma
Decompress .lzma file.
unmount
Disconnects a file systems and remote resources.
unpack
Expands a compressed file.
until
Execute a set of actions while/until conditions are evaluated TRUE.
unxz
Decompress .xz files.
unzip
List, test and extract compressed files in a ZIP archive.
uptime
Display information about how long the system has been running.
useradd
Create a new user or updates default new user information.
userdel
Remove a users account.
usermod
Modify a users account.
vacation
Reply to mail automatically.
vgrind
“Grind” nice program listings
vi
Screen-oriented (visual) display editor based on ex.
vim
A programmer’s text editor.
view
A programmer’s text editor.
vipw
A special command to safely edit password files.
visudo
A special command to safely edit the “sudoers” file.
vmstat
Reports statistics about virtual memory usage.
w
Show who is logged on and what they are doing.
wait
Await process completion.
wall
Send a message to everybody’s terminal.
wc
Displays a count of lines, words, and characters in a file
wget
Downloads files via HTTP or FTP, such as web pages.
whatis
Displays short manual page descriptions.
whereis
Locate a binary, source, and manual page files for a command.
while
Repetitively execute a set of actions while/until conditions are evaluated TRUE.
which
Locate a command.
who
Displays who is on the system.
whoami
Print effective userid.
whois
Internet user name directory service.
write
Send a message to another user.
X
Execute the X Window System.
Xorg
The executable of the X Window System server.
xargs
Build and execute complex commands across multiple files.
xfd
Display all the characters in an X font.
xhost
Server access control program for X.
xinit
The initializer of the X Window System.
xlsfonts
Server font list displayer for X.
xset
User preference utility for X.
xterm
Terminal emulator for X.
xrdb
X server resource database utility.
xz
Compress files to .xz files.
xzcat
View compressed .xz files.
yacc
Short for yet another compiler-compiler, yacc is a compiler.
yes
Repeatedly output a line with all specified STRING(s), or ‘y’.
yppasswd
Changes network password in the NIS database.
yum
Interactive rpm based package manager.
zcat
Compress files.
zip
Compression and file packaging utility.
zipinfo
Display technical information about a zip file.
