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.

OpenID
or
Sign in Register

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

Hide

Credits

Site by David Winterbottom (user root).

Commands using head from sorted by
Terminal - Commands using head - 226 results
while [ 1 -lt 2 ]; do i=0; COL=$((RANDOM%$(tput cols)));ROW=$((RANDOM%$(tput cols)));while [ $i -lt $COL ]; do tput cup $i $ROW;echo -e "\033[1;34m" $(cat /dev/urandom | head -1 | cut -c1-1) 2>/dev/null ; i=$(expr $i + 1); done; done
2010-05-28 16:07:56
User: dave1010
Functions: cat cut expr head tput
Tags: bash Matrix Style
1
Up
Down
Blue Matrix

Same as original, but works in bash

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
while :; do integer i=0; COL=$((RANDOM%$(tput cols))); ROW=$((RANDOM%$(tput cols))); while (( i <= COL)) do tput cup $i $ROW; echo "\033[1;34m" $(cat /dev/urandom | head -1 | cut -c1-1) 2>/dev/null; i=$(expr $i + 1); done done
2010-05-28 11:17:43
User: mfrancime
Functions: cat cut echo expr head tput
Tags: Matrix Style
-4
Up
Down
Blue Matrix

Matrix Screen HPUX

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
finger @www.linuxbanks.cn | grep -oE '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}' | head -n1
2010-05-05 14:58:55
User: zhangweiwu
Functions: finger grep head
Tags: ip address
-4
Up
Down
find out public ip address by using any host that have 'efingerd -n'

This is useful when you got a reserved IP address like 192.168.0.100 and want to find out what IP address is used to access the Internet. You have to know a server with 'efingerd -n' configured, like www.linuxbanks.cn as above.

Other method to find out this information are for example access www.tell-my-ip.com and grep the output. The finger method have the advantage that it is easy to deploy a service like www.tell-my-ip.com, as you only need to get efingerd installed.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
date +%s | sha256sum | base64 | head -c <length>; echo
2010-04-30 22:05:11
User: markdrago
Functions: date head
2
Up
Down
Produce a pseudo random password with given length in base 64
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
/sbin/ifconfig|grep -B 1 inet |head -1 | awk '{print $5}'
2010-04-22 06:35:29
User: octopus
Functions: awk grep head
Tags: Network Linux UNIX
-2
Up
Down
Find MAC address of Active Eth connection
Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cut -d\ -f 1 ~/.bash_history | sort | uniq -c | sort -rn | head -n 10 | sed 's/.*/ &/g'
2010-04-06 22:48:26
User: er0k
Functions: cut head sed sort uniq
1
Up
Down
most used unix commands
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
curl http://www.reddit.com/r/wallpapers.rss | grep -Eo 'http:[^&]+jpg' | head -1 | xargs feh --bg-seamless
2010-03-27 00:08:40
User: shavenwarthog
Functions: grep head xargs
4
Up
Down
set desktop background to highest-rated image from Reddit /r/wallpapers

You'll need "feh" to set the background from the commandline. Install with "apt-get install feh"

Thanks to the Redditors on this thread: http://www.reddit.com/r/linux/comments/bira4/is_there_a_linux_version_of_this_preferably_a/

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
pronounce(){ wget -qO- $(wget -qO- "http://dictionary.reference.com/browse/$@" | grep 'soundUrl' | head -n 1 | sed 's|.*soundUrl=\([^&]*\)&.*|\1|' | sed 's/%3A/:/g;s/%2F/\//g') | mpg123 -; }
2010-03-13 04:23:56
User: matthewbauer
Functions: grep head mpg123 sed wget
Tags: audio sed wget eval pronounce aplay English dictionary dictionary.com
13
Up
Down
Pronounce an English word using Dictionary.com

This one uses dictionary.com

Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
alias busy='my_file=$(find /usr/include -type f | sort -R | head -n 1); my_len=$(wc -l $my_file | awk "{print $1}"); let "r = $RANDOM % $my_len" 2>/dev/null; vim +$r $my_file'
2010-03-09 21:48:41
User: busybee
Functions: alias awk find head sort vim wc
Tags: bash vim sort awk find wc
22
Up
Down
Makes you look busy

This makes an alias for a command named 'busy'. The 'busy' command opens a random file in /usr/include to a random line with vim. Drop this in your .bash_aliases and make sure that file is initialized in your .bashrc.

Comments (8) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
git log -g --pretty=oneline | grep '}: commit' | awk '{print $1}' | head -1 | xargs git checkout -f
2010-03-09 16:56:39
User: jimthunderbird
Functions: awk grep head xargs
0
Up
Down
Update the working tree to the latest git commit
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
TOTAL_RAM=`free | head -n 2 | tail -n 1 | awk '{ print $2 }'`; PROC_RSS=`ps axo rss,comm | grep [h]ttpd | awk '{ TOTAL += $1 } END { print TOTAL }'`; PROC_PCT=`echo "scale=4; ( $PROC_RSS/$TOTAL_RAM ) * 100" | bc`; echo "RAM Used by HTTP: $PROC_PCT%"
2010-02-26 20:29:45
User: d34dh0r53
Functions: awk echo grep head tail
6
Up
Down
Print Memory Utilization Percentage For a specific process and it's children

Change the name of the process and what is echoed to suit your needs. The brackets around the h in the grep statement cause grep to skip over "grep httpd", it is the equivalent of grep -v grep although more elegant.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
newest () { DIR=${1:-'.'}; CANDIDATE=`find $DIR -type f|head -n1`; while [[ ! -z $CANDIDATE ]]; do BEST=$CANDIDATE; CANDIDATE=`find $DIR -newer "$BEST" -type f|head -n1`; done; echo "$BEST"; }
2010-02-04 12:40:44
User: shadycraig
Functions: echo head
Tags: bash find files recursive
1
Up
Down
A function to find the newest file in a directory

Works recusivley in the specified dir or '.' if none given.

Repeatedly calls 'find' to find a newer file, when no newer files exist you have the newest.

In this case 'newest' means most recently modified. To find the most recently created change -newer to -cnewer.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
du -s * | sort -nr | head | cut -f2 | parallel -k du -sh
2010-01-28 12:59:14
User: unixmonkey8046
Functions: cut du head sort
Tags: du xargs parallel
-2
Up
Down
List top ten files/directories sorted by size

If a directory name contains space xargs will do the wrong thing. Parallel https://savannah.nongnu.org/projects/parallel/ deals better with that.

Show sample output | Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
paste -d "." <(curl http://.../dist.female.first http://.../dist.male.first | cut -d " " -f 1 | sort -uR) <(curl http://..../dist.all.last | cut -d " " -f 1 | sort -R | head -5163) | tr "[:upper:]" "[:lower:]" | sed 's/$/@test.domain/g'
2010-01-21 19:52:28
User: connorsy
Functions: cut head paste sed sort tr
0
Up
Down
Create unique email addresses directly from the US census site*Full command in comments

** Replace the ... in URLS with:

www.census.gov/genealogy/www/data/1990surnames

Couldn't fit in 256

Created on Ubuntu 9.10 but nothing out of the ordinary, should work anywhere with a little tweaking. 5163 is the number of unique first names you get when combine the male and female first name files from. http://www.census.gov/genealogy/www/data/1990surnames/names_files.html

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ifconfig | grep -B 1 "inet addr:" | head -1 | cut -d" " -f1
2010-01-04 23:02:57
User: jasonwalsh
Functions: cut grep head ifconfig
-2
Up
Down
Get name of first configured interface

Get the line containing "inet addr:" and the line before that, get down to only the first line, and then get the first word on that line, which should be the interface.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
tr -dc 'a-zA-Z0-9' < /dev/urandom | head -c10
2009-12-01 14:22:20
User: Phil
Functions: head tr
-1
Up
Down
generate random password

A slightly shorter version. Also doesn't put a return character at the end of the password

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat *.c | { printf "se te du\nplot '-' t '' w dots\n"; tr '[[:upper:]]' '[[:lower:]]' | tr -s [[:punct:][:space:]] '\n' | sort | uniq -c | sort -nr | head -n 100 | awk '{print $1}END{print "e"}'; } | gnuplot
2009-11-20 14:53:26
User: taliver
Functions: awk cat head printf sort tr uniq
5
Up
Down
Plot frequency distribution of words from files on a terminal.

Uses the dumb terminal option in gnuplot to plot a graph of frequencies. In this case, we are looking at a frequency analysis of words in all of the .c files.

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
mkpasswd() { head -c $(($1)) /dev/urandom | uuencode - | sed -n 's/.//;2s/\(.\{'$1'\}\).*/\1/p' ;}
2009-11-19 14:27:52
User: taliver
Functions: head sed uuencode
-3
Up
Down
Random password generating function

This uses urandom to produce a random password. The random values are uuencoded to ensure only printable characters. This only works for a number of characters between 1 and 60.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for i in *.avi; do echo -n "$i:";mediainfo $i|head | grep PlayTime | cut -d: -f2 ; done | sort -t: -k2 -r
2009-11-09 12:42:20
User: yooreck
Functions: cut echo grep head sort
0
Up
Down
Sort movies by length, longest first

Similar but using mediainfo instead of totem-something

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ps -eo pcpu,user,pid,cmd | sort -r | head -5
2009-11-03 14:41:55
User: ferqwerty
Functions: head ps sort
1
Up
Down
Display top 5 processes consuming CPU
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
shuf -i 1-49 | head -n6 | sort -n| xargs
2009-10-22 12:54:08
User: ioggstream
Functions: head sort
5
Up
Down
lotto generator

note the xargs at the end

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
echo $(shuf -i 1-49 | head -n6 | sort -n)
2009-10-22 06:48:20
User: twfcc
Functions: echo head sort
7
Up
Down
lotto generator
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for f in *.html; do head -n -1 $f > temp; cat temp > $f; rm temp; done
2009-10-12 12:49:18
User: Sunng
Functions: cat head rm
-1
Up
Down
remove the last line of all html files in a directory

Some malicious program appends a iframe or script tag to you web pages on some server, use this command to clean them in batch.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
head -c10 <(echo $RANDOM$RANDOM$RANDOM)
2009-10-09 15:09:02
User: jgc
Functions: echo head
Tags: HEAD random
0
Up
Down
Outputs a 10-digit random number

Makes use of $RANDOM environment variable.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
tr -c -d 0-9 < /dev/urandom | head -c 10
2009-10-09 11:58:30
User: hfs
Functions: head tr
Tags: HEAD tr urandom
2
Up
Down
Outputs a 10-digit random number
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate