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).

All commands from sorted by
Terminal - All commands - 11,369 results
wget -q -O- http://www.gutenberg.org/dirs/etext96/cprfd10.txt | sed '1,419d' | tr "\n" " " | tr " " "\n" | perl -lpe 's/\W//g;$_=lc($_)' | grep "^[a-z]" | awk 'length > 1' | sort | uniq -c | awk '{print $2"\t"$1}'
2009-05-04 16:00:39
User: alperyilmaz
Functions: awk grep perl sed sort tr uniq wget
Tags: sort perl sed awk uniq wget tr
-4
Up
Down
count occurences of each word in novel David Copperfield

This command might not be useful for most of us, I just wanted to share it to show power of command line.

Download simple text version of novel David Copperfield from Poject Gutenberg and then generate a single column of words after which occurences of each word is counted by sort | uniq -c combination.

This command removes numbers and single characters from count. I'm sure you can write a shorter version.

Show sample output | Comments (8) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep '' -m X file1 > file2
2009-03-22 04:34:43
User: sardanapalos
Functions: grep
-4
Up
Down
extract a certain number of lines from a file and dump them to another file

It extracts X number of lines from file1 and dumps them to file2.Using grep with the empty string '' extracts the complete lines (i.e. no filtering takes place) and the -m flag indicates how many lines to extract out from the given file. Then using the redirect > operator we send the extracted lines to a new file.

Comments (6) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
wget -q -O - www.myip.cn | grep -Po "(\d+\.){3}\d+" -m 0
2012-11-22 06:53:42
User: huazhihao
Functions: grep wget
-4
Up
Down
show WAN IP
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
while (( $i != 0 )) { smbstatus; sleep 5; clear }
2009-06-03 13:26:30
User: unixmonkey4084
Functions: clear sleep
Tags: unix samba zsh
-4
Up
Down
See smbstatus all the time

See smbstatus Output within a 5 second interval (for monitoring smb access)

Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
svn status app/models/foo.rb; svn commit -m "Changed file" !$
2009-03-22 23:14:06
User: ggoodale
Tags: bash shortcut global
-4
Up
Down
!$ - The last argument to the previous command

After a command is run in bash, !$ is set to the last (space-delimited) argument of the command. Great for running several commands against the same file in a row.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
sh default values
2010-03-26 02:36:57
User: rootgeek
Functions: sh
Tags: foundry
-4
Up
Down
Display default values on Foundry (Brocade) RX and MLX BigIron L3 (routers & switches)
Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
PID=httpd ; ps aux | grep $PID | grep -v grep | awk '{print $2}' | xargs kill -9
2012-02-21 23:27:47
User: esaenz
Functions: awk grep kill ps xargs
-4
Up
Down
kill all pids from $PID

# define user pid to kill

PID=httpd ;

# kill all pids

ps aux | grep $PID | grep -v grep | awk '{print $2}' | xargs kill -9

Show sample output | Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
if lynx --dump http://twitter.com/xmuda | grep -q "Sorry, that page does"; then echo "Dont Exist"; else echo "Exist"; fi
2013-03-23 16:12:24
User: xmuda
Functions: echo grep
-4
Up
Down
Twitter Account Validator

I use these command to validate twitter accounts, we can use a "for a in $(cat list.txt)" to validate a complete list of twitter accounts.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
dm ?
2010-03-26 02:42:21
User: rootgeek
Tags: foundry
-4
Up
Down
Dispaly a bunch of Info. on Foundry (Brocade) RX and MLX BigIron L3 (routers & switches)

The sample output, is the command with a ?, to show you all the stuff you can look at.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
Place a filename at the beginning of the line to make it easier to edit the search at the end of the command.
2009-02-07 12:03:19
User: iveney
Functions: at make
-4
Up
Down
Place a filename at the beginning of the line to make it easier to edit the search at the end of the command. Place a filename at the beginning of the line to make it easier to edit the search at the end of the command.
Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
alias w3m='w3m -cookie'
2009-07-09 09:01:55
User: freestyler
Functions: alias
-4
Up
Down
let w3m usecookie
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ntfsfix /dev/hda1
2011-07-02 17:49:48
User: 0disse0
Tags: ntfs
-4
Up
Down
forcing Windows to do the scandisk during boot

This command marks it as "dirty" NTFS partition, forcing Windows to do the scandisk during boot. It is convenient if you work hard to NTFS partitions under Linux

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
newhostname=$(hostname | awk -F. '{print $1 "." $2}'); ipaddress=$(nslookup `hostname` | grep -i address | awk -F" " '{print $2}' | awk -F. '{print $3 "." $4}' | grep -v 64.142);PS1="[`id -un`.$newhostname.$ipaddress]"' (${PWD}): '; export PS1
2009-02-16 20:11:53
User: simardd
Functions: awk export grep hostname nslookup
-4
Up
Down
change your PS1 to look better :)

changes the PS1 to something better than default.

[username.hostname.last-2-digits-of-ip] (current directory)

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
uuencode -m <filename> <filename>
2009-12-22 15:28:59
User: leprasmurf
Functions: uuencode
Tags: uuencode uudecode file transfer
-4
Up
Down
Copy a file over SSH without SCP

I have come across multiple situations where I could only get to a server from a very restrictive bounce point which would not allow file transfers. I was able to uuencode a file, copy the output to a text file over putty, and then uudecode the file to transfer it. This works with any kind of file.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep --exclude-dir=.svn --exclude=*~ -i "TODO" -rl .
2011-04-06 20:25:41
User: saibbot
Functions: grep
-4
Up
Down
Find the files that include a TODO statement within a project
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
sed '1,55d'
2009-02-16 20:36:25
User: grep
Functions: sed
-4
Up
Down
delete first X lines of a file

deletes first 55 lines; change the 55 to whatever number

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ping -c 10 hostname
2009-03-04 06:14:52
User: haivu
Functions: ping
Tags: Network
-4
Up
Down
Ping 10 times then quit

On Linux and Mac systems (I have not tested with other Unix systems), the ping command will keep on pinging until the user interrupts it with Ctrl+C. On Windows system, ping will execute for a number of times then quit. The -c flag on Linux and Mac will make this happen

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find directory/ |xargs grep -i "phrase"
2010-01-26 14:56:56
User: tuxtutorials
Functions: find grep xargs
-4
Up
Down
Recursively grep thorugh directory for string in file.

Recursive grep through directory for file.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -name .svn -type d | parallel rm -rf
2011-07-05 00:25:51
User: evandrix
Functions: find rm
-4
Up
Down
Recursively remove all .svn directories
Comments (6) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
w ; pkill -kill -t pts/1
2013-08-14 18:57:25
User: yangfeng724
-4
Up
Down
pkill
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
marbles () { c=''; for i in $(seq $1); do c+='{b,r}'; done; x=$(eval echo $c); p=''; for i in $(seq $2); do p+='b*r'; done; y=$(grep -wo "${p}b*" <<< $x); wc -l <<< "$y"; grep -vc 'rr' <<< "$y"; }
2010-08-27 23:04:33
User: quintic
Functions: echo eval grep seq wc
Tags: echo grep seq wc eval brace expansion
-4
Up
Down
Function to solve a simple combinatorial maths puzzle from the command line

Suppose you have 11 marbles, 4 of which are red, the rest being blue. The marbles are indistinguishable, apart from colour. How many different ways are there to arrange the marbles in a line? And how many ways are there to arrange them so that no two red marbles are adjacent?

There are simple mathematical solutions to these questions, but it's also possible to generate and count all possibilities directly on the command line, using little more than brace expansion, grep and wc!

The answer to the question posed above is that there are 330 ways of arranging the marbles in a line, 70 of which have no two red marbles adjacent. See the sample output.

To follow the call to marbles 11 4: after c=''; for i in $(seq $1); do c+='{b,r}'; done;, $c equals {b,r}{b,r}{b,r}{b,r}{b,r}{b,r}{b,r}{b,r}{b,r}{b,r}{b,r}

After x=$(eval echo $c), and brace expansion, $x equals bbbbbbbbbbb bbbbbbbbbbr ... rrrrrrrrrrb rrrrrrrrrrr, which is all 2^11 = 2048 strings of 11 b's and r's.

After p=''; for i in $(seq $2); do p+='b*r'; done;, $p equals b*rb*rb*rb*r

Next, after y=$(grep -wo "${p}b*"

Finally, grep -vc 'rr'

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ps -auwx|egrep hunger|grep -v grep| awk '{print "kill -9",$1}' > ~/fu.bar
2009-02-05 11:43:38
User: lendellray
Functions: awk ps
-4
Up
Down
find all processes named hunger and force kill, minus the grep itself and output to a file called fu.bar
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
!previous_command
2009-02-20 18:07:03
User: jcgam69
-4
Up
Down
run a previous command

Only a few characters of the previous command are necessary.

Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
function expand-tabs() { expand -t 8 "$1" > "$1.expanded"; mv -f "$1.expanded" "$1"; }
2011-01-28 16:03:37
User: unixmonkey17279
Functions: expand mv
-4
Up
Down
Expand tabs

I don't like TABs in sources files because in case of mixture of TABs and spaces they looks in different editors. Even worse mixing TABs and spaces could be a problem when you use Python.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -type f -name \*.php | while IFS="" read i; do expand -t4 "$i" > "$i-"; mv "$i-" "$i"; done
2011-04-08 12:53:14
User: flatcap
Functions: expand find mv read
Tags: find read expand spaces unexpand tabs whitespace
-4
Up
Down
Replace spaces with tabs & format file source recursively within a directory

Recursively find php files and replace tab characters with spaces.

Options:

"\*.php" -- replace this with the files you wish to find

"expand" -- replace tabs with spaces (use "unexpand" to replace spaces with tabs)

"-t4" -- tabs represent 4 spaces

Note: The IFS="" in the middle is to prevent 'read' from eating leading/trailing whitespace in filenames.

Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate