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.

Universal configuration monitoring and system of record for IT.

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:



May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

Top Tags





Commands tagged Linux from sorted by
Terminal - Commands tagged Linux - 238 results
apt-get remove $(dpkg -l | awk "/^ii linux-(image|headers)/ && ! /`uname -r`/ {print \$2}")
2011-10-09 13:58:47
User: _john
Functions: apt awk

since awk was already there one can use it instead of the 2 greps. might not be faster, but fast enough

sed 's/.$//' Win-file.txt
tr -d "\r" < dos.txt > linux.txt
while true ; do nc -l 80 < index.html ; done
2011-08-31 15:17:33
User: ztank1013
Functions: true

Very simple web server listening on port 80 will serve index.html file or whatever file you like pointing your browser at http://your-IP-address/index.html for example.

If your web server is down for maintenance and you'd like to inform your visitors about it, quickly and easily, you just have to put into the index.html file the right HTML code and you are done! Of course you need to be root to run the command using port 80.

find /var/spool/mqueue -type f -mtime +7 | perl -lne unlink
2011-08-19 15:22:02
User: mengesb
Functions: find perl

Find all files in /var/spool/mqueue older than 7 days, pass to perl to efficiently delete them (faster than xargs or -exec when you've got millions or hundreds of thousands to delete). Naturally the type, directory, and file age vars can be adjusted to meet your specific needs.

ln -nsf <TARGET> <LINK>
2011-07-14 14:07:06
User: rdc
Functions: ln
Tags: Linux symlinks

Instead of deleting an existing symlink and then re-creating it pointing at the new location, it is possible to perform the same action with this one command.

Interesting discussion on whether this is possible to do atomically here: http://answers.google.com/answers/threadview?id=526119

find /myfs -size +209715200c -exec du -m {} \; |sort -nr |head -10
2011-07-07 21:12:46
User: arlequin
Functions: du find head sort

Specify the size in bytes using the 'c' option for the -size flag. The + sign reads as "bigger than". Then execute du on the list; sort in reverse mode and show the first 10 occurrences.

ykpersonalize -1 -ostatic-ticket -ostrong-pw1 -ostrong-pw2
2011-05-13 04:00:52

By default, slot 1 is used for OTP purposes and validates against the Yubikey servers. Running the command above will replace that. If you have a Yubikey 2 or above, you can change -1 to -2 and program the second slot with a strong static key.

ip addr show eth0 | grep ether | awk '{print $2}'
2011-05-01 19:54:46
User: ryanc
Functions: awk grep
Tags: Network Linux

Linux specific, requires iproute2 (but most distros have that by default now)

chage -d 0 -m 0 -M 60 [user]
2011-04-28 02:19:59
User: mack
Functions: chage

This command is Linux compatible.

It will prompt the user for a new password at next logon

sudo aptitude remove -P $(dpkg -l|awk '/^ii linux-image-2/{print $2}'|sed 's/linux-image-//'|awk -v v=`uname -r` 'v>$0'|sed 's/-generic//'|awk '{printf("linux-headers-%s\nlinux-headers-%s-generic\nlinux-image-%s-generic\n",$0,$0,$0)}')
2011-04-25 05:19:57
User: Bonster
Functions: awk sed sudo

Same as 7272 but that one was too dangerous

so i added -P to prompt users to continue or cancel

Note the double space: "...^ii␣␣linux-image-2..."

Like 5813, but fixes two bugs: [1]This leaves the meta-packages 'linux-headers-generic' and 'linux-image-generic' alone so that automatic upgrades work correctly in the future. [2]Kernels newer than the currently running one are left alone (this can happen if you didn't reboot after installing a new kernel).

fig2dev -L eps file.fig file.eps
2011-04-25 01:02:25
User: droidery29
Tags: Linux

There is a huge number of supported "languages" to which you can export your .fig figures to. See. 'man fig2dev' (http://linux.die.net/man/1/fig2dev).

php -r 'function a(){$i=10;while($i--)echo str_repeat(" ",rand(1,79))."*".PHP_EOL;}$i=99;while($i--){a();echo str_repeat(" ",34)."Happy New Year 2011".PHP_EOL;a();usleep(200000);}'
2011-04-21 05:08:56
User: galymzhan
Functions: echo
Tags: Linux PHP

Requires installed command line PHP. Also, try at different dimensions of terminal window

function rot13 { if [ -r $1 ]; then cat $1 | tr '[N-ZA-Mn-za-m5-90-4]' '[A-Za-z0-9]'; else echo $* | tr '[N-ZA-Mn-za-m5-90-4]' '[A-Za-z0-9]'; fi }
2011-03-18 09:59:41
User: twjolson
Functions: cat echo tr
Tags: Linux unix tr

Will rot 13 whatever parameter follows 'rot13', whether it is a string or a file. Additionally, it will rot 5 each digit in a number

alias rot13="tr a-zA-Z n-za-mN-ZA-M"
aptitude remove $(dpkg -l|awk '/^ii linux-image-2/{print $2}'|sed 's/linux-image-//'|awk -v v=`uname -r` 'v>$0'|sed 's/-generic//'|awk '{printf("linux-headers-%s\nlinux-headers-%s-generic\nlinux-image-%s-generic\n",$0,$0,$0)}')
2010-12-11 11:38:15
User: __
Functions: awk sed

Note the double space: "...^ii␣␣linux-image-2..."

Like 5813, but fixes two bugs: [1]This leaves the meta-packages 'linux-headers-generic' and 'linux-image-generic' alone so that automatic upgrades work correctly in the future. [2]Kernels newer than the currently running one are left alone (this can happen if you didn't reboot after installing a new kernel).

I'm bummed that this took 228 characters. I'd like to see a simpler version.

for I in `/sbin/lspci |awk '/VGA/{print $1}'`;do /sbin/lspci -v -s $I;done
lspci -v -s `lspci | awk '/VGA/{print $1}'`
2010-10-26 17:45:14
User: infinull
Functions: awk lspci
Tags: Linux hardware

probably only works if you have one graphics card.

used this: http://www.cyberciti.biz/faq/howto-find-linux-vga-video-card-ram/

as reference

can be expanded, for example:

lspci -v -s `lspci | awk '/VGA/{print $1}'` | sed -n '/Memory.*, prefetchable/s/.*\[size=\([^]]\+\)\]/\1/p'

will just get the amount of prefetchable memory

compare to:

lshw -C display

which does not give the size (it does give byte ranges and you could calculate the size from that, but that's a pain)

Also uses a command which is not standard on linux; wheras lspci is a core utility provided by most systems

inotifywait -mrq -e CREATE --format %w%f /path/to/dir | while read FILE; do chmod g=u "$FILE"; done
2010-10-21 23:36:02
User: dooblem
Functions: chmod read

Listens for events in the directory. Each created file is displayed on stdout. Then each fileline is read by the loop and a command is run.

This can be used to force permissions in a directory, as an alternative for umask.

More details:


Check the Description below.
2010-10-07 04:22:32
User: hunterm

The command was too long for the command box, so here it is:

echo $(( `wget -qO - http://i18n.counter.li.org/ | grep 'users registered' | sed 's/.*\<font size=7\>//g' | tr '\>' ' ' | sed 's/<br.*//g' | tr ' ' '\0'` + `curl --silent http://www.dudalibre.com/gnulinuxcounter?lang=en | grep users | head -2 | tail -1 | sed 's/.*<strong>//g' | sed 's/<\/strong>.*//g'` ))

This took me about an hour to do. It uses wget and curl because, dudalibre.com blocks wget, and wget worked nicely for me.

wget -qO - http://i18n.counter.li.org/ | grep 'users registered' | sed 's/.*\<font size=7\>//g' | tr '\>' ' ' | sed 's/<br.*//g' | tr ' ' '\0'
sudo hwinfo --framebuffer
2010-10-03 14:45:02
User: hute37
Functions: sudo

look at /boot/grub/menu.lst for somethig like:

## additional options to use with the default boot option, but not with the

## alternatives

## e.g. defoptions=vga=791 resume=/dev/hda5

## defoptions=vga=795

# defoptions=vga=873

## altoption boot targets option

## multiple altoptions lines are allowed

## e.g. altoptions=(extra menu suffix) extra boot options

## altoptions=(recovery) single

# altoptions=(verbose mode) vga=775 debug

# altoptions=(console mode) vga=ask

# altoptions=(graphic mode) quiet splash

# altoptions=(recovery mode) single

vga=(decimal value) is framebuffer mode

wget -O - 'https://USERNAMEHERE:PASSWORDHERE@mail.google.com/mail/feed/atom' --no-check-certificate
2010-09-26 14:47:13
User: PLA
Functions: wget

I use this command in my Conky script to display the number of messages in my Gmail inbox and to list the from: and subject: fields.

sudo ls -l $(eval echo "/proc/{$(echo $(pgrep java)|sed 's/ /,/')}/fd/")|grep log|sed 's/[^/]* //g'|xargs -r tail -f
2010-07-30 18:20:00
User: vutcovici
Functions: echo eval grep ls sed sudo tail xargs

Tail all logs that are opened by all java processes. This is helpful when you are on a new environment and you do not know where the logs are located. Instead of java you can put any process name. This command does work only for Linux.

The list of all log files opened by java process:

sudo ls -l $(eval echo "/proc/{$(echo $(pgrep java)|sed 's/ /,/')}/fd/")|grep log|sed 's/[^/]* //g'
for i in *.flac; do gst-launch filesrc location="$i" ! flacdec ! wavenc ! filesink location="${i%.flac}.wav"; done
2010-07-17 22:48:22

Takes all .flac directories, feeds them into a simple transcode pipeline to spit out .wavs with the same name (but correct extension).