Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

Hide

News

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

All commands from sorted by
Terminal - All commands - 11,611 results
cal -3
2009-04-02 17:40:38
User: haivu
Functions: cal
Tags: PIM
-3

the -3 show the previous, current, and next month.

whatis [command-name]
2009-04-02 17:30:13
User: haivu
Functions: whatis
5

The whatis command displays a short description for the command you list on the command line. It is useful to quickly learn what a command does

sudo vi /etc/fstab; Go//smb-share/gino /mnt/place smbfs defaults,username=gino,password=pass 0 0<esc>:wq; mount //smb-share/gino
2009-04-02 16:04:35
User: GinoMan2440
Functions: mount sudo vi
4

the middle command between the ; and ; is the vi commands that insert that line into the last line of the file, the esc with the carets is literally hitting the escape key, you have to have the smbfs package installed to do it, I use it to access my iTunes music on my mac from my linux PC's with amarok so I can play the music anywhere in the house. among other things, it allows you to access the files on that share from your computer anytime you're on that network.

save_state=$(stty -g);echo -n "Password: ";stty -echo;read password;stty "$save_state";echo "";echo "You inserted $password as password"
2009-04-02 15:57:05
User: acirulli
Functions: stty
5

Allow to read password in a script without showing the password inserted by the user

find . -type f -size +25000k -exec ls -lh {} \; | awk '{ print $8 ": " $5 }'
dstat -ta
read -p 'Username: ' u;sudo -H -u $u xauth add $(xauth list|grep :$(echo ${DISPLAY: -4:2}));sudo su - $u
nmap -sP your network/submask | awk "/^Host/"'{ print $2 }'
2009-04-02 12:41:54
User: rauhmaru
Functions: awk
0

This command will display only the hosts that are active in the network.

Ctrl+S Ctrl+Q
2009-04-02 09:27:09
User: elementa13
15

These are simple shortcuts to pause and continue terminal output, works in most terminals and screen multiplexers like screen. You can use it to catch something if things change too fast, and scroll with Shift + PgUp PgDown. On linux console ScrollLock can also be used.

echo $( (( $( (2**31 -1) ) - $(date +%s) )) )
2009-04-02 05:14:23
User: Chartreuse
Functions: date echo
Tags: bash echo date
0

Echos the number of seconds from the current time till the specified time (Example in command is (2**31-1)) aka the Unix epoch. Just replace that number with the specified date (in seconds past Jan. 1st 1970) and it will return the seconds.

NOTE: Only works in bash

true && { echo success;} || { echo failed; }
2009-04-02 01:49:25
Functions: echo true
23

This will perform one of two blocks of code, depending on the condition of the first. Essentially is a bash terniary operator.

To tell if a machine is up:

ping -c1 machine { echo succes;} || { echo failed; }

Because of the bash { } block operators, you can have multiple commands

ping -c1 machine && { echo success;log-timestamp.sh }|| { echo failed; email-admin.sh; }

Tips:

Remember, the { } operators are treated by bash as a reserved word: as such, they need a space on either side.

If you have a command that can fail at the end of the true block, consider ending said block with 'false' to prevent accidental execution

import -pause 5 -window root desktop_screenshot.jpg
2009-04-01 22:37:33
Tags: ImageMagick
9

Requires ImageMagick. Takes a screenshot 5 seconds after it's run and saves it as desktop_screenshot.jpg Particularly handy when made into a menu option or button.

u=`curl -d 'dl.start=Free' $(curl $1|perl -wpi -e 's/^.*"(http:\/\/rs.*)" method.*$/$1/'|egrep '^http'|head -n1)|grep "Level(3) \#2"|perl -wpi -e 's/^.*(http:\/\/rs[^\\\\]*).*$/$1/'`;sleep 60;wget $u
while true; do ifconfig eth0 | grep "inet addr:"; sleep 60; done;
2009-04-01 19:29:28
User: bandit36
Functions: grep ifconfig sleep
Tags: script while loop
-5

You can use this to loop any command to periodically see the output.

while true; do [YOUR COMMAND HERE]; sleep [# of seconds]; done;

Alternatively, you can put it in a simple shell script to save typing!

#/!bin/bash

while true; do $1; sleep $2; done;

/path/to/script.sh "ifconfig eth0 | grep 'inet addr:'" 60
find ./ -not -type d | xargs wc -l | cut -c 1-8 | awk '{total += $1} END {print total}'
echo "string" | sed -e 's/.*match1//' -e 's/match2.*$//'
2009-04-01 15:01:27
User: P17
Functions: echo sed
-3

But who knows to delete the rest of the lines?

I want only "string".

fuser -vm /dev/sda2
2009-04-01 13:51:38
User: jcm357
Functions: fuser
-12

Com o fuser voce descobre quem esta ocupando o dispositivo.

Depois pode desativar o servico manualmente. Ou se necessario, matar o servico com Kill, usando o numero PID.

ex: kill -9 1768

fonte: http://www.vivaolinux.com.br/dica/Desmontando-um-dispositivo-ocupado

perl -ne 'while (/([0-9]+\.){3}[0-9]+/g) {print "$&\n"};' file.txt
mysql -uadmin -p`cat /etc/psa/.psa.shadow` -e "use psa; select accounts.password FROM accounts JOIN mail ON accounts.id=mail.account_id WHERE mail.mail_name='webmaster';"
2009-04-01 13:32:36
User: darkon1365
3

This simply pulls the password out of the database for the given mail name for ease of use in testing emails that you would not normally have access to.

rsync --partial --progress --rsh=ssh $file_source $user@$host:$destination_file
2009-04-01 13:13:14
User: dr_gogeta86
Functions: rsync
23

It can resume a failed secure copy ( usefull when you transfer big files like db dumps through vpn ) using rsync.

It requires rsync installed in both hosts.

rsync --partial --progress --rsh=ssh $file_source $user@$host:$destination_file local -> remote

or

rsync --partial --progress --rsh=ssh $user@$host:$remote_file $destination_file remote -> local

man beep | sed -e '1,/Note/d; /BUGS/,$d' | awk '{print $2}' | xargs -IX sudo beep -f X -l 500
2009-04-01 06:48:48
User: jnash
Functions: awk man sed sudo xargs
4

Are there any creative pieces of music that can be created using beep and the shell? I'd love to hear it!

startx -- `which Xvfb` :1 -screen 0 800x600x24 && DISPLAY=:1 x11vnc
2009-04-01 03:51:35
User: Spaz
17

This starts an X server using Xvfb(1) (no graphics hardware required), then starts a VNC server on the display. Change :1 if there's a conflict with an existing display, and change 800x600x24 to suit your tastes (24 is the bit depth, 800x600 is the size). This command obviously requires X be installed, and also x11vnc(1); both are available via your favourite package manager. You can also use another VNC server of your choosing, as long as DISPLAY is set to the display of Xvfb(1). To change your desktop environment (the default is twm(1), which is rather fail), you can add it to your ~/.xinitrc file (see the startx(1) manpage for details).

while true; do [ "$(ping -c1W1w1 server-or-ip.com | awk '/received/ {print $4}')" != 1 ] && beep; sleep 1; done
2009-03-31 20:47:56
User: sudopeople
Functions: sleep
14

pings a server once per second, and beeps when the server is unreachable.

Basically the opposite of:

ping -a server-or-ip.com

which would beep when a server IS reachable.

You could also substitute beep with any command, which makes this a powerful alternative to ping -a:

while true; do [ "$(ping -c1W1w1 server-or-ip.com 2>/dev/null | awk '/received/ {print $4}')" = 1 ] && date || echo 'server is down!'; sleep 1; done

which would output the date and time every sec until the ping failed, in which case it would echo.

Notes:

Requires beep package.

May need to run as root (beep uses the system speaker)

Tested on Ubuntu which doesn't have beep out of the box...

sudo apt-get install beep
find . -name "*.py" -exec grep -n -H -E "^(import|from) math" {} \;
for i in $(seq 1 11) 13 14 15 16; do man iso-8859-$i; done
2009-03-31 19:40:15
User: penpen
Functions: man seq
Tags: Linux unix
-2

Depending on the installation only certain of these man pages are installed. 12 is left out on purpose because ISO/IEC 8859-12 does not exist. To also access those manpages that are not installed use opera (or any other browser that supports all the character sets involved) to display online versions of the manpages hosted at kernel.org:

for i in $(seq 1 11) 13 14 15 16; do opera http://www.kernel.org/doc/man-pages/online/pages/man7/iso_8859-$i.7.html; done