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 grep from sorted by
Terminal - Commands using grep - 1,506 results
while true ; do IFS="" read i; echo "$i"; sleep .01; done < <(tr -c "[:digit:]" " " < /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]")
2009-07-22 03:59:07
User: friedchuckles
Functions: dd echo grep read sleep tr true
Tags: color
2
Up
Down
Matrix Style

Same as above but slooooow it down

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
/sbin/ifconfig | grep inet | cut -f 2 -d ":" | cut -f 1 -d " "
2009-07-21 21:42:04
User: random_bob
Functions: cut grep
-1
Up
Down
Read just the IP address of a device

another way to output the IP address' of the system

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for i in `git log --all --oneline --format=%h`; do git grep SOME_STRING $i; done
2009-07-21 19:14:51
User: mad
Functions: grep
Tags: git
1
Up
Down
search string in _all_ revisions
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
/sbin/ifconfig eth0 | grep "inet addr" | sed -e 's/.*inet addr:\(.*\) B.*/\1/g'
2009-07-21 14:10:39
User: digitalmechanic
Functions: grep sed
Tags: IP
-2
Up
Down
Read just the IP address of a device
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat `whereis mysqlbug | awk '{print $2}'` | grep 'CONFIGURE_LINE='
2009-07-21 07:44:27
User: numbata
Functions: awk cat grep
Tags: mysql
0
Up
Down
Determine configure options used for MySQL binary builds
Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ps -u $USER |grep $1 | awk '{ print $1}'| xargs kill
2009-07-20 10:06:32
User: buffer
Functions: awk grep ps xargs
-4
Up
Down
Kill a process with its name

Well this can come handy , when you don't feel like playing with pid rather if you know

the process name say "firefox",it would kill it.The script given below would kill the process with its name given as first parameter , though not robust enough to notify that process doesn't exist , well if you know what you are doing that's wouldn't be a problem.:)

----

killhim.sh

----

#!/bin/bash

ps -u $USER |grep $1 | awk '{ print $1}'| xargs kill

----

Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
lsof -i -n -P | grep :80
2009-07-17 15:56:19
User: reeyuk
Functions: grep
0
Up
Down
what?s running on a given port on your machine?
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep -Ir foo *
2009-07-17 15:30:10
User: libdave
Functions: grep
0
Up
Down
recursive grep of text files

short command to find a string in all text files in all subdirectories, excluding all files grep does not deem text files.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
$ grep -or string path/ | wc -l
2009-07-16 12:50:59
User: ioggstream
Functions: grep wc
Tags: awk grep cut arithmetic
9
Up
Down
count how many times a string appears in a (source code) tree

grep -o puts each occurrence in a separate line

Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
while true; do netstat -p |grep "tcp"|grep --color=always "/[a-z]*";sleep 1;done
2009-07-16 04:52:49
User: buffer
Functions: grep netstat
-4
Up
Down
Monitor Applications application that are connected/new connections

The -p parameter tell the netstat to display the PID and name of the program to which each socket belongs or in digestible terms list the program using the net.Hope you know what pipe symbol means!

Presently we wish to only moniter tcp connections so we ask grep to scan for string tcp, now from the op of grep tcp we further scan for regular expression /[a-z]*.

Wonder what that means ?

If we look at the op of netstat -p we can see that the name of the application is preceded by a / ( try netstat -p ) so,now i assume application name contains only characters a to z (usually this is the case) hope now it makes some sense.Regular expression /[a-z]* means to scan a string that start with a / and contains zero or more characters from the range a-z !!. Foof .. is t

Show sample output | Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep -rc logged_in app/ | cut -d : -f 2 | awk '{sum+=$1} END {print sum}'
2009-07-15 14:16:44
User: terceiro
Functions: awk cut grep
Tags: awk grep cut arithmetic
-2
Up
Down
count how many times a string appears in a (source code) tree

grep's -c outputs how may matches there are for a given file as "file:N", cut takes the N's and awk does the sum.

Show sample output | Comments (6) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
vim $(grep test *)
2009-07-15 10:15:04
User: goatboy
Functions: grep test vim
Tags: vim grep
4
Up
Down
Find files containing string and open in vim

I often use "vim -p" to open in tabs rather than buffers.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
export LANG=C; grep string longBigFile.log
2009-07-14 12:48:02
User: ioggstream
Functions: export grep
Tags: grep LANG
0
Up
Down
Fast grepping (avoiding UTF overhead)

greps using only ascii, skipping the overhead of matching UTF chars.

Some stats:

$ export LANG=C; time grep -c Quit /var/log/mysqld.log

7432

real 0m0.191s

user 0m0.112s

sys 0m0.079s

$ export LANG=en_US.UTF-8; time grep -c Quit /var/log/mysqld.log

7432

real 0m13.462s

user 0m9.485s

sys 0m3.977s

Try strace-ing grep with and without LANG=C

Comments (6) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -name '*.html' -print0| xargs -0 -L1 cat |sed "s/[\"\<\>' \t\(\);]/\n/g" |grep "http://" |sort -u
2009-07-14 07:00:15
User: jamespitt
Functions: cat find grep sed sort xargs
4
Up
Down
find external links in all html files in a directory list

Just a handy way to get all the unique links from inside all the html files inside a directory. Can be handy on scripts etc.

Show sample output | Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
tar cvfz changes.tar.gz --exclude-vcs `svn diff -rM:N --summarize . | grep . | awk '{print $2}' | grep -E -v '^\.$'`
2009-07-13 19:39:10
User: jaysee
Functions: awk diff grep tar
2
Up
Down
Get a range of SVN revisions from svn diff and tar gz them

Handy when you need to create a list of files to be updated when subversion is not available on the remote host. You can take this tar file, and upload and extract it where you need it. Replace M and N with the revisions specific to yours. Make sure you do this from an updated (svn up) working directory.

Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep <pattern> -R . --exclude-dir='.svn'
2009-07-13 19:08:53
User: log0
Functions: grep
Tags: grep
2
Up
Down
Search through files, ignoring .svn
Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
fmiss() { grep -RL "$*" * }
2009-07-13 18:30:54
User: inkel
Functions: grep
Tags: grep
1
Up
Down
Find files with lines that do not match a pattern

This one would be much faster, as it's only one executed command.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
tokill=`ps -fea|grep process|awk '{ printf $2" "}'`; kill -9 $tokill;
2009-07-11 01:40:29
User: jhansen
Functions: awk grep kill printf
-3
Up
Down
kill some process (same as others) but parsing to a variable
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ssh root@server 'tail --max-unchanged-stats=10 -n0 -F /var/log/auth.log ' | grep Accepted | while read l ; do kdialog --title "SSH monitor" --passivepopup "$l" 3; done
2009-07-10 14:25:35
User: skygreg
Functions: grep read ssh
0
Up
Down
SSH monitor
Comments (2) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
sudo port installed | grep -v 'active\|The' | xargs sudo port uninstall
2009-07-09 05:15:30
User: letterj
Functions: grep sudo xargs
-1
Up
Down
Uninstall all MacPorts that are no longer active
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep -r 'keyword keyword2' your/path/ | grep -v svn
2009-07-08 20:48:11
User: anis
Functions: grep
-2
Up
Down
find a word in multiple files avoiding svn

this command searches for a keyword or an expression in a path and avoids versionned files

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find . -not \( -name .svn -prune \) -type f -print0 | xargs --null grep <searchTerm>
2009-07-08 20:08:05
User: qazwart
Functions: find grep xargs
Tags: find xargs grep
7
Up
Down
Search through files, ignoring .svn

By putting the "-not \( -name .svn -prune \)" in the very front of the "find" command, you eliminate the .svn directories in your find command itself. No need to grep them out.

You can even create an alias for this command:

alias svn_find="find . -not \( -name .svn -prune \)"

Now you can do things like

svn_find -mtime -3
Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
unzip -lt foo.zip | grep testing | awk '{print $2}' | xargs rm -r
2009-07-08 00:13:10
User: copremesis
Functions: awk grep rm xargs
2
Up
Down
Remove annoying files from recently extracted zip archive

Inspired by http://www.commandlinefu.com/commands/view/2573/remove-all-files-previously-extracted-from-a-tar.gz-file. .... yet for zip files

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
LC_ALL=C tr -c "[:digit:]" " " < /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]"
2009-07-02 07:10:33
User: zzambia
Functions: dd grep tr
Tags: color
6
Up
Down
Matrix Style

Solves "tr" issues with non C-locales under BSD-like systems (like OS X)

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep -v "\ *#\|^$" /etc/path/to.config
2009-06-30 18:14:46
User: geekboxjockey
Functions: grep
2
Up
Down
Dump a configuration file without comments or whitespace...

A short, *easy-er* to remember command for stripping whitespace and comments from a config file, (or any file for that matter).

Remember regex as:

slash, space, star.

pound, slash, bar.

pointy-hat, dollar. (or "caret, dollar" if you must)

:-P

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate