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.

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

Commands using echo from sorted by
Terminal - Commands using echo - 1,221 results
echo {1..199}" sheep," | espeak -v english -s 80
2009-09-03 10:08:12
User: MrMerry
Functions: echo
6

Can change language and speed, see espeak man page for options. (Install espeak in your linux distro via yum or apt-get)

For insomniacs you may need to enclose in a while true; do ...; done loop ;)

echo sortmeplease | grep -o . | sort | tr -d '\n'; echo
2009-09-03 00:52:49
User: MrMerry
Functions: echo grep sort tr
1

Sorts a character string, using common shell commands.

echo "5 k 3 5 / p" | dc
2009-09-03 00:21:54
User: xamaco
Functions: echo
1

using bc is for sissies. dc is much better :-D

Polish notation will rule the world...

for dnsREC in $(curl -s http://www.iana.org/assignments/dns-parameters |grep -Eo ^[A-Z\.]+\ |sed 's/TYPE//'); do echo -n "$dnsREC " && dig +short $dnsREC IANA.ORG; done
xmms2 pause && echo "xmms2 play" | at now +5min
2009-08-30 04:35:10
User: Vrekk
Functions: at echo
2

you can also run "xmms2 pause & at now +5min

echo "${PATH//:/$'\n'}"
for i in 192.168.1.{61..71};do ping -c 1 $i &> /dev/null && echo $i;fi;done
2009-08-26 06:04:24
User: AlecSchueler
Functions: echo ping
Tags: Network ssh bash
-2

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.

echo "xmms2 play" | at 6:00
2009-08-26 04:20:24
User: Vrekk
Functions: at echo
1

Nice little alarm clock to wake you up on time (hopefully).

You can also do 'echo "vlc path/to/song" | at 6:00

echo "0t${currentEpoch}=Y" | /usr/bin/adb
2009-08-25 12:17:01
User: verboEse
Functions: echo
0

this works on Solaris, so not better than the "only-GNU"-tool :-(

I think, there is no one-liner for this, that will work on all *nix-es

echo "aBcDeFgH123" | tr a-z A-Z
echo 1234567890 | awk '{ print strftime("%c", $0); }'
2009-08-25 09:37:54
User: alvinx
Functions: awk echo
7

- convert unixtime to human-readable with awk

- useful to read logfiles with unix-timestamps, f.e. squid-log:

sudo tail -f /var/log/squid3/access.log | awk '{ print strftime("%c ", $1) $0; }

echo `date +%m/%d/%y%X |awk '{print $1;}' `" => "` cat /proc/acpi/thermal_zone/THRM/temperature | awk '{print $2, $3;}'` >> datetmp.log
2009-08-24 21:26:29
User: ninadsp
Functions: awk cat echo
7

Uses the data in the /proc system, provided by the acpid, to find out the CPU temperature. Can be run on systems without lm-sensors installed as well.

y=http://www.youtube.com;for i in $(curl -s $f|grep -o "url='$y/watch?v=[^']*'");do d=$(echo $i|sed "s|url\='$y/watch?v=\(.*\)&.*'|\1|");wget -O $d.flv "$y/get_video.php?video_id=$d&t=$(curl -s "$y/watch?v=$d"|sed -n 's/.* "t": "\([^"]*\)",.*/\1/p')";done
2009-08-22 21:31:29
User: matthewbauer
Functions: echo grep sed
3

This will download a Youtube playlist and mostly anything http://code.google.com/apis/youtube/2.0/reference.html#Video_Feeds

The files will be saved by $id.flv

pgrep -u `id -u` firefox-bin || find ~/.mozilla/firefox -name '*.sqlite'|(while read -e f; do echo 'vacuum;'|sqlite3 "$f" ; done)
2009-08-22 10:36:05
User: kamathln
Functions: echo find read
11

Sqlite database keeps collecting cruft as time passes, which can be cleaned by the 'vacuum;' command. This command cleans up the cruft in all sqlite files relating to the user you have logged in as. This command has to be run when firefox is not running, or it will exit displaying the pid of the firefox running.

for u in `cut -f1 -d: /etc/passwd`; do echo -n $u:; groups $u; done | sort
2009-08-22 09:06:02
User: hemanth
Functions: echo groups
Tags: sort cut for groups
3

"cut" the user names from /etc/passwd and then running a loop over them.

echo $(( $RANDOM % 10 + 1 ))
echo init 0 | at now + 2 hours
echo "scale=4; 3 / 5" | bc
2009-08-21 21:51:46
User: foob4r
Functions: echo
3

allows you to use floating point operations in shell scripts

sync; echo 3 > /proc/sys/vm/drop_caches
watch() { t=$1; shift; while test :; do clear; date=$(date); echo -e "Every "$t"s: $@ \t\t\t\t $date"; $@; sleep $t; done }
watch() { while test :; do clear; date=$(date); echo -e "Every "$1"s: $2 \t\t\t\t $date"; $2; sleep $1; done }
echo sleep() begins: %TIME% && FOR /l %a IN (10,-1,1) do (ECHO 1 >NUL %as&ping -n 2 -w 1 127.0.0.1>NUL) && echo sleep() end: %TIME%
2009-08-19 13:43:09
User: pfredrik
Functions: echo
-2

Enable 'sleep' function in Windows environment where this does not exist, although not exact in time. (there is a delay for each ping) This is a simple way to separate commands with a time-period.

S=$SSH_TTY && (sleep 3 && echo -n 'Peace... '>$S & ) && (sleep 5 && echo -n 'Love... '>$S & ) && (sleep 7 && echo 'and Intergalactic Happiness!'>$S & )
2009-08-19 07:57:16
User: AskApache
Functions: echo sleep
-2

Ummmm.. Saw that gem on some dead-head hippies VW bus at phish this summer.. It's actually one of my favorite ways of using bash, very clean. It shows what you can do with the cool advanced features like job control, redirection, combining commands that don't wait for each other, and the thing I like the most is the use of the ( ) to make this process heirarchy below, which comes in very handy when using fifos for adding optimization to your scripts or commands with similar acrobatics.

F UID PID PPID WCHAN RSS PSR CMD

1 gplovr 30667 1 wait 1324 1 -bash

0 gplovr 30672 30667 - 516 3 \_ sleep 3

1 gplovr 30669 1 wait 1324 1 -bash

0 gplovr 30673 30669 - 516 0 \_ sleep 5

1 gplovr 30671 1 wait 1324 1 -bash

0 gplovr 30674 30671 - 516 1 \_ sleep 7

echo "nohup command rm -rf /phpsessions 1>&2 &>/dev/null 1>&2 &>/dev/null&" | at now + 3 hours 1>&2 &>/dev/null
2009-08-18 07:31:17
User: AskApache
Functions: at echo
1

This is helpful for shell scripts, I use it in my custom php install script to schedule to delete the build files in 3 hours, as the php install script is completely automated and is made to run slow.

Does require at, which some environments without crontab still do have.

You can add as many commands to the at you want. Here's how I delete them in case the script gets killed. (trapped)

atq |awk '{print $1}'|xargs -iJ atrm J &>/dev/null

urls=('www.ubuntu.com' 'google.com'); for i in ${urls[@]}; do http_code=$(curl -I -s $i -w %{http_code}); echo $i status: ${http_code:9:3}; done