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.

UpGuard checks and validates configurations for every major OS, network device, and cloud provider.

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



All commands from sorted by
Terminal - All commands - 12,420 results
dd if=/dev/zero of=/dev/hda bs=16M
2009-11-09 00:13:35
User: Clopnixus
Functions: dd

If you leave out the block size it defaults to 512 bytes. I set it to 16 Megabytes and it was much faster...

Taskkill /?

Taskkill: As the name of the utility ?taskkill? suggests that it is simply used to see the running processes and to kill one or more processes either by using its PID i.e. ProcessID or by using its Image name i.e. by which it is present in system and being executed. We can also filter the results on the basis of user name, PID, image name, CPU time, memory usage etc at the time of killing or terminating a process.


taskkill [/s [/u [\] [/p []]]] {[/fi ] [...] [/pid /im ]} [/f] [/t]

Parameters description:

/s :- To provide IP specification or name of the remote computer; if not provided local computer is considered. Do not use backslashes in the value of the parameter.

/u \ :- To provide UserName or Domain\UserName under whose permission command should execute. If not provided then command run under the permission of person who is logged on. Option /u can be used only if /s is specified.

/p :- For the password of that user account which is provided with /u parameter. Password is prompted in case this field is omitted.

/fi :- To apply filter to select a set of tasks. Wildcard character (*) can be used for specifying all tasks or image names. Filter names are provided after parameter description.

/pid >ProcessID> :- For specifying PID of the process to be killed.

/im :- For providing image name of the process to be terminated. Also Wildcard character (*) can be used to specify all image names.

/t :- To terminate the whole tree of the process including all child processes started by it.

/f :- For forceful termination of process. It is not omitted in case of remote process as they are terminated forcefully in default.

Filters description:

Filters are provided to filter the result. This filtering is based on some Filter names which are checked with some relational operators. You will observe that the filter names are the column names which comes in task manager.

Filter Name Valid Operators Valid Values


IMAGENAME eq, ne Name of image

PID eq, ne, gt, lt, ge, le ProcessID number

SESSION eq, ne, gt, lt, ge, le Session number

CPUTIME eq, ne, gt, lt, ge, le CPU time in the format HH:MM:SS, where MM and SS are between 0 and 59 and HH is any unsigned number

MEMUSAGE eq, ne, gt, lt, ge, le Memory usage(in KB)

USERNAME eq, ne Any valid user name (User or Domain\User)

SERVICES eq, ne Service name

WINDOWTITLE eq, ne Window title

MODULES eq, ne DLL name

where eq, ne, gt, lt, ge & le are meant for equal to, not equal to, greater than, less than, greater than equal to and less than equal to respectively.

Points to be noted:

In case of remote process WINDOWTITLE and STATUS filters are not supported.

Wildcard (*) character is accepted for /im option only when filter is applied.

Not necessary that /f is specified in case of remote process termination as in default that is terminated forcefully.

Don?t specify computer name to HOSTNAME filter as it will result in a shutdown and all processes are stopped.

For specifying ProcessID (PID) tasklist command can be used.


To terminate a process with PID 3276 use parameter /pid.

?taskkill /pid 3276

To terminate more than one process with pid as 2001, 2224, 4083.

?taskkill /pid 2001 /pid 2224 /pid 4083

To terminate a process with its image name like wmplayer.exe for Windows Media Player use /im parameter.

?taskkill /im wmplayer.exe

To terminate a process and all its child process i.e. to end process tree in task manager use /t parameter. ?taskkill /f /im explorer.exe /t

To terminate all those processes which have PID greater than or equal to 1500 without considering their image names use filter ge with wildcard character.

?taskkill /f /fi ?PID ge 1500? /im *

To terminate the process tree with PID 2521 which is started by account name admin.

?taskkill /pid 2521 /t /fi ?USERNAME eq admin?

To terminate all process beginning with note on a remote system named serverpc under user name ?administrator? having its password as [email protected]()r3?.

?taskkill /s serverpc /u administrator /p [email protected]()r3 /fi ?IMAGENAME eq note*? /im *

To terminate a process with its windows title as ?paint?

?taskkill /f /fi ?WINDOWTITLE eq paint?

Source: http://unlock-windows.blogspot.com/2008/12/taskkill-command-line-utility.html

python -c "import SimpleHTTPServer;SimpleHTTPServer.test()"
2009-08-29 12:08:30
User: unixbhaskar
Functions: last
Tags: login shell

This command will reveal login has been made to the system as well as when the reboot occurs. It uses a file called /var/log/wtmp,which captures all the information about the successful login and reboot information. It has many switch ,by which you can get an idea when people login how long they stay.

mount |tail -1 | less -p "/dev/[^ ]*"
ln -s /destinationTarget /sourceTarget/newFolder
2009-03-12 01:56:34
User: topgun553
Functions: ln

if you wanted to create a new folder called "red" that was a symbolic link from /home/music/ to /home/hobbies/art then you would type:

ln -s /home/hobbies/art /home/music/red

gpg --refresh-keys
wb(){ for i in $(wget -O- -U "" "http://wallbase.cc/random/23/eqeq/1920x1080/0/" --quiet|grep wallpaper/|grep -oe 'http://wallbase.[^"]*'); do if (( n > "$1" )); then break;fi;let n++;wget $(wget -O- -U "" $i --quiet|grep -oe 'http://[^"]*\.jpg');done;}
aptitude search \~ilinux-image
gocr -i ~/Screenshot.png
2013-02-28 07:38:13
User: totti

Image to text converter.

Convert your scanned book in image format like .png, .jpg into editable text format.

OCR ==> Optical Code Reader

2009-05-19 19:07:11

From man tiger : Tiger is a package consisting of Bourne Shell scripts, C code and data files which is used for checking for security problems on a UNIX system. It scans system configuration files, file systems, and user configuration files for possible security problems and reports them.

mate - `find . -name 'filename'`
cat welcome | wall
2009-02-14 18:12:50
User: Williebee
Functions: cat

Show message in file "welcome" to all logged in terminal users.

2009-04-22 06:54:20
User: eastwind

tell you how many Non free software is on your machine, which package it is and which restriction on freedom it has . require vrms package , vrms mean virtual Richard M. Stallman :)

ls | perl -lne '++$x{lc $1} if /[.](.+)$/ }{ print for keys %x'
2010-08-13 20:05:15
User: recursiverse
Functions: ls perl

All with only one pipe. Should be much faster as well (sort is slow). Use find instead of ls for recursion or reliability.

Edit: case insensitive

awk '{if (NR % 2 == 0) print $0}' file.txt
echo '!'whammy
2009-03-26 23:34:33
User: sudopeople
Functions: echo
Tags: literal bang

Seems obvious, but other seemingly simple ways to use it don't work:

echo !whammy


echo "!whammy"

both output:

-bash: !whammy: event not found

and this:

echo "\!whammy"



with the slash :(

you can also do any combinations of quotes for a complex string:

echo "It's great to be able to use a bang ("'!'") in a command"'!'


It's great to be able to use a bang (!) in a command!
s=`head -$i fileName | tail -1`
mkdir ${1..10}
ls -ad .*
2009-02-18 15:22:39
User: osantana
Functions: ls

List only hidden files (or directories). You also can use:

ls -lad .*
rename .txt .md *.txt
ls | while read -r FILE; do mv -v "$FILE" `echo $FILE | tr -d ' '`; done
2010-08-14 14:10:48
User: IgnitionWeb
Functions: ls mv read tr
Tags: space echo while tr

all files in the directory get moved, in doing so the new name of the file is the original name with out spaces (using translate command)

while true ; do scripts/bootstrap.py ; ./manage.py runserver ; done
2009-03-27 04:43:54
User: taurus
Functions: true

I wrote a script called bootstrap.py to delete the database, then load a new database with initial values. With this single-line shell loop, when I need to make a schema change (which happens often in the early stages of some projects), I hit ctrl-C to stop the running Django server, then watch bootstrap.py do its thing, then watch the server restart.

0,30 * * * * php -q /address/to/script.php
2010-01-11 10:44:13
User: dotanmazor

Just put this line in a file that resides in your /etc/cron.d/ folder, and you're set.

The -q option is used to suppress php headers.