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.

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.

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 - 12,229 results
2009-03-25 07:25:33
User: dizzgo
Tags: Ubuntu

release upgrades are major upgrades as from 8.04 to 8.10 or from 8.10 to 9.04

update-manager-core must be installed:

sudo apt-get install update-manager-core

in some cases you must edit '/etc/update-manager/release-upgrades' and set 'Prompt=normal'

gs -sDEVICE=pswrite -sOutputFile=- -q -dNOPAUSE With-Fonts.pdf -c quit | ps2pdf - > No-Fonts.pdf
2009-03-25 03:46:00
User: qubyte
Functions: gs

It's sometimes useful to strip the embedded fonts from a pdf, for importing into something like Inkscape. Be warned, this will increase the size of a pdf substantially.

I tried this with only gs writing with -sDEVICE=pdfwrite but it doesn't seem to work, so I just pipe postscript output to ps2pdf for the same effect.

swapoff -a ; swapon -a
2009-03-25 03:30:41
User: alperyilmaz
Functions: swapoff swapon
Tags: swapoff swapon

When you run a memory intensive application (VirtualBox, large java application, etc) swap area is used as soon as memory becomes insufficient. After you close the program, the data in swap is not put back on memory and that decreases the responsiveness. Swapoff disables the swap area and forces system to put swap data be placed in memory. Since running without a swap area might be detrimental, swapon should be used to activate swap again.

Both swapoff and swapon require root privileges.

watch -n 7 -d 'uptime | sed s/.*users,//'
2009-03-25 02:52:36
User: detert
Functions: sed watch

helps you keep watch on the load of a system, without having to stare constantly at the terminal. The -d argument to watch highlights the difference from the last run, making it easier to note how the load is fluctuating. The sed command just strips off the information about how long the box has been up, and how many users are logged in.

mount -t smbfs //$server/share /local/mount -o rw,username=$USER
2009-03-25 01:05:17
User: sufoo
Functions: mount

Mount an smb share with this command. other options -ousername=$USERr,gid=$groupname,scope=rw

awk '{sum+=$1; sumsq+=$1*$1} END {print sqrt(sumsq/NR - (sum/NR)**2)}' file.dat
seq 0 0.1 20 | awk '{print $1, cos(0.5*$1)*sin(5*$1)}' | graph -T X
2009-03-24 21:46:59
User: kaan
Functions: awk seq

The arguments of "seq" indicate the starting value, step size, and the end value of the x-range. "awk" outputs (x, f(x)) pairs and pipes them to "graph", which is part of the "plotutils" package.

seq 6 | awk '{for(x=1; x<=5; x++) {printf ("%f ", rand())}; printf ("\n")}'
2009-03-24 21:33:38
User: kaan
Functions: awk printf seq
Tags: awk seq

Displays six rows and five columns of random numbers between 0 and 1. If you need only one column, you can dispense with the "for" loop.

awk '{sum1+=$1; sum2+=$2} END {print sum1/NR, sum2/NR}' file.dat
2009-03-24 21:22:14
User: kaan
Functions: awk
Tags: awk

This example calculates the averages of column one and column two of "file.dat". It can be easily modified if other columns are to be averaged.

mplayer -vo null -vc null -ao pcm:fast:file=file.wav file.mp3; faac -b 128 -c 44100 -w file.wav
2009-03-24 21:04:35
User: llama

I use this to convert mp3 files to m4a files that can be used as ringtones on the iPhone. I've documented the process here: http://www.control-d.com/?p=60

find -depth . | (while read FULLPATH; do BASENAME=`basename "${FULLPATH}"`; DIRNAME=`dirname "${FULLPATH}"`; mv "${DIRNAME}/${BASENAME}" "${DIRNAME}/${BASENAME// /_}"; done)
2009-03-24 21:04:32
User: mohan43u
Functions: find mv read

Takes filenames and directory names and replace space to '_'.

rpm -qa --qf '%{name}-%{version}-%{release}.%{arch}\n'
2009-03-24 20:42:17
User: llama
Functions: rpm
Tags: rpm

The queryformat option can be used in a number of ways to find things like duplicate packages, wrong arch, or the exact package to pass to rpm -e, yum remove, etc.

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

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

"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.


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 user@server&; 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

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

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

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

verifry if link detected or no and speed of network.