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.


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.
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

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!
Hide

Top Tags

Hide

Functions

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

All commands from sorted by
Terminal - All commands - 12,361 results
seq 50| awk 'BEGIN {a=1; b=1} {print a; c=a+b; a=b; b=c}'
2009-03-24 20:39:24
User: kaan
Functions: awk seq
Tags: awk seq
13

Another combination of seq and awk. Not very efficient, but sufficiently quick.

snmpwalk -v3 -On -u <user> -l AuthPriv -a SHA -A <auth_password> -X <encryption_password> -m ALL <HOST_IP> .
snmpwalk -v3 -On -u <user> -l AuthNoPriv -a SHA -A <auth_password> -m ALL <HOST_IP> .
snmpwalk -v3 -On -u <user> -l AuthNoPriv -a MD5 -A <auth_password> -m ALL <HOST_IP> .
snmpwalk -v3 -On -u <user> -l NoAuthNoPriv -m ALL <HOST_IP> .
snmpwalk -v2c -c <community> -m ALL <HOST_IP> .
seq 100 | awk '{sum+=$1} END {print sum}'
2009-03-24 20:30:40
User: kaan
Functions: awk seq
Tags: awk seq
4

"seq 100" outputs 1,2,..,100, separated by newlines. awk adds them up and displays the sum.

"seq 1 2 11" outputs 1,3,..,11.

Variations:

1+3+...+(2n-1) = n^2

seq 1 2 19 | awk '{sum+=$1} END {print sum}' # displays 100

1/2 + 1/4 + ... = 1

seq 10 | awk '{sum+=1/(2**$1)} END {print sum}' # displays 0.999023
alias tproxy='ssh -ND 8118 [email protected]&; export LD_PRELOAD="/usr/lib/libtsocks.so"'
alias myip='curl -s www.wieistmeineip.de | egrep -o "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}"'
sed 's/\b\(0*\)//g' filename
2009-03-24 20:19:42
User: alperyilmaz
Functions: sed
Tags: sed
2

Leading zeros might help correct sorting and they can be removed by sed after sorting

sed -e :a -e 's/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/;ta' filename
2009-03-24 20:06:02
User: alperyilmaz
Functions: sed
Tags: sed
3

Does not necessarily require a file to process, it can be used in a pipe as well:

cat filename | sed -e :a -e 's/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/;ta'

I don't remember where I copy/pasted this from, I wish I credited the original author

head -c $((<pw-lenght>-2)) /dev/urandom | uuencode -m - | sed -e '1d' -e '3d' | sed -e 's/=.*$//g'
2009-03-24 20:05:16
User: P17
Functions: head sed uuencode
-2

Replace < pw-length > with the desired password-length.

The password-length is not always correct, but wayne...

watch ethtool eth0
2009-03-24 20:03:25
User: israel
Functions: watch
0

verifry if link detected or no and speed of network.

mysql DATABASE -N -s -r -e 'SQL COMMAND'
2009-03-24 19:53:46
User: alperyilmaz
Tags: mysql
8

-N removes header

-s removes separator chars

-r raw output

After using these options, the MySQL ouptut can be used with pipes very easily

ps ax | grep <processname> | grep -v grep | awk '{print $1}' | sudo xargs kill -9
php -r 'echo strtotime("2009/02/13 15:31:30")."\n";'
2009-03-24 19:38:46
User: sudopeople
7

Most people know that you can run a PHP script from the command line like so:

php ./my_script.php

But sometimes I just want to run a quick bit of code, the PHP Command Line Interface allows me to do so with the -r option.

Requires package php5-cli

rpm -Va | grep -v "\.\.\.\.\.\.\.T"
cat -v -t -e
2009-03-24 19:29:03
User: alperyilmaz
Functions: cat
Tags: cat
4

Useful to detect number of tabs in an empty line, DOS newline (carriage return + newline).

A tool that can help you understand why your parsing is not working.

man -t man | lp
2009-03-24 19:08:07
User: icco
Functions: man
Tags: printing
4

man -t manpagename gives a postscript version of said man page. You then pipe it to ls, and assuming you have cups set up, it prints in your default printer.

echo -e "[client]\nuser = YOURUSERNAME\npassword = YOURPASSWORD" > ~/.my.cnf
2009-03-24 19:05:39
User: alperyilmaz
Functions: echo
Tags: mysql bash
0

The file .my.cnf located at user's home directory is used for mysql login. If this file exists, then

mysql -uYOURUSERNAME -pYOURPASSWORD database -e 'SOME SQL COMMAND'

can be replaced with

mysql database -e 'SOME SQL COMMAND'

It saves you from typing!

This is valid for mysqladmin and mysqldump commands as well.

/usr/sbin/arp -i eth0 | awk '{print $3}' | sed 1d
date -d "@$(find dir -type f -printf '%C@\n' | sort -n | sed -n "$(($(find dir -type f | wc -l)/2))p")" +%F
2009-03-24 18:48:49
User: allengarvin
Functions: date dir find wc
-1

I needed to get a feel for how "old" different websites were, based on their directories.

vimdiff foo.c <(bzr cat -r revno:-2 foo.c)
gs -q -sPAPERSIZE=a4 -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=test.pdf multipageproject.pdf
2009-03-24 17:14:46
User: iain
Functions: gs
3

Xsane produces PDFs that are too large - particularly multipage PDFs. This command compresses them. If you do not use A4, remove the -sPAPERSIZE flag.

tar -czf - * | ssh example.com "cat > files.tar.gz"
2009-03-24 17:02:02
User: migurski
Functions: ssh tar
5

I recently found myself with a filesystem I couldn't write to and a bunch of files I had to get the hell out of dodge, preferably not one at a time. This command makes it possible to pack a bunch of files into a single archive and write it to a remote server.