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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.




Commands using cat from sorted by
Terminal - Commands using cat - 430 results
cat VIDEO_TS/VTS_01_[1234].VOB | nice ffmpeg -i - -s 512x384 -vcodec libtheora -acodec libvorbis ~/Videos/dvd_rip.ogg
2010-09-14 14:45:27
User: zhangweiwu
Functions: cat nice
Tags: ffmpeg dvd

To rip DVD movie to ogg format using ffmpeg, follow these steps.

1) find the vob files on the mounted video DVD in VIDEO_TS that stores the movie itself. There would be a few other VOB files that stores splash screen or special features, the vob files for the movie itself can be identified by its superior size. You can verify these vob files by playing them directly with a player (e.g. mplayer)

2) concatenate all such vob files, pipe to ffmpeg

3) calculate the video size and crop size. The ogg video size must be multiple of 16 on both width and height, this is inherit limitation of theora codec. In my case I took 512x384.

The -vcodec parameter is necessary because ffmpeg doesn't support theora by itself. -acodec is necessary otherwise ffmpeg uses flac by default.

pdftk pdfname.pdf cat 1E output outputname.pdf
while [[ COUNTER -le 10 && IFS=':' ]]; do for LINE in $(cat /tmp/list); do some_command(s) $LINE; done; COUNTER=$((COUNTER+1)); done
2010-09-01 15:09:59
User: slashdot
Functions: cat

At times I find that I need to loop through a file where each value that I need to do something with is not on a separate line, but rather separated with a ":" or a ";". In this instance, I create a loop within which I define 'IFS' to be something other than a whitespace character. In this example, I iterate through a file which only has one line, and several fields separated with ":". The counter helps me define how many times I want to repeat the loop.

pdftk first.pdf second.pdf cat output output.pdf
wget http://forums.dropbox.com && wget $(cat index.html|grep "Latest Forum Build"|cut -d"\"" -f2) && wget $(cat topic.php*|grep "Linux x86:"|cut -d"\"" -f2|sort -r|head -n1) && rm -rf ~/.dropbox* && rm index.html *.php* && tar zxvf dropbox-*.tar.gz -C ~/
cat b1.avi b2.avi b3.avi b4.avi b5.avi b6.avi b7.avi > output.avi; mencoder -forceidx -oac copy -ovc copy output.avi -o output_final.avi; rm output.avi
cat | bash
2010-08-18 13:47:46
User: glaudiston
Functions: cat

Sometimes you don't want to leave history, because of passwords use or somethink like.

I think it help.

cls(){ printf "\033c";} or, if no printf, cat > c ;<ctrl+v> <ctrl+[>c <enter><ctrl-d> c(){ cat c;} #usage: c
cat $(ls -c | grep ogg | tac ) > directory/test.ogg
tee >(cat - >&2)
2010-07-20 17:22:31
User: camocrazed
Functions: cat tee

the tee command does fine with file names, but not so much with file descriptors, such as &2 (stderr). This uses process redirection to tee to the specified descriptor.

In the sample output, it's being used to tee to stderr, which is connected with the terminal, and to wc -l, which is also outputting to the terminal. The result is the output of bash --version followed by the linecount

cat /proc/acpi/thermal_zone/THRM/temperature
2010-07-11 16:07:07
User: gunslinger_
Functions: cat
Tags: temperature

Displaying system temperature your system .

shellcode version @ http://inj3ct0r.com/exploits/12554

cat file_with_tabs.txt | perl -pe 's/\t/ /g'
2010-07-11 13:01:22
User: nikc
Functions: cat perl
Tags: cat perl replace

Replaces tabs in output with spaces. Uses perl since sed seems to work differently across platforms.

cat WAR_AND_PEACE_By_LeoTolstoi.txt | tr -cs "[:alnum:]" "\n"| tr "[:lower:]" "[:upper:]" | awk '{h[$1]++}END{for (i in h){print h[i]" "i}}'|sort -nr | cat -n | head -n 30
2010-07-05 06:39:20
User: cp
Functions: awk cat head sort tr


cat WAR_AND_PEACE_By_LeoTolstoi.txt | tr -cs "[:alnum:]" "\n"| tr "[:lower:]" "[:upper:]" | sort -S16M | uniq -c |sort -nr | cat -n | head -n 30

("sort -S1G" - Linux/GNU sort only) will also do the job but as some drawbacks (caused by space/time complexity of sorting) for bigger files...

cat my.ps | nc -q 1 hp4550.mynet.xx 9100
find /var/log/apache2 -name 'access.log*gz' -exec zcat {} \; -or -name 'access.log*' -exec cat {} \;
2010-06-19 08:35:12
User: recursiverse
Functions: cat find zcat

This command allows you to stream your log files, including gziped files, into one stream which can be piped to awk or some other command for analysis.

Note: if your version of 'find' supports it, use:

find /var/log/apache2 -name 'access.log*gz' -exec zcat {} + -or -name 'access.log*' -exec cat {} +
cat /proc/acpi/battery/*/state
cat VTS_05_1.VOB VTS_05_2.VOB VTS_05_3.VOB VTS_05_4.VOB > mergedmovie.mpg
cat /proc/acpi/battery/BAT0/state
cat /proc/acpi/ac_adapter/AC0/state
cat /proc/acpi/ac_adapter/ACAD/state
cat > {filename} {your text} [^C | ^D]
mysqldump -q --skip-opt --force --log-error=dbname_error.log -uroot -pmysqlpassword dbname | ssh -C user@sshserver 'cd /path/to/backup/dir; cat > dbname.sql'
2010-05-29 23:06:04
User: esplinter
Functions: cat ssh

backup big mysql db to remote machine over ssh. "--skip-opt" option is needed when you can?t allocate full database in ram.

while [ 1 -lt 2 ]; do i=0; COL=$((RANDOM%$(tput cols)));ROW=$((RANDOM%$(tput cols)));while [ $i -lt $COL ]; do tput cup $i $ROW;echo -e "\033[1;34m" $(cat /dev/urandom | head -1 | cut -c1-1) 2>/dev/null ; i=$(expr $i + 1); done; done
2010-05-28 16:07:56
User: dave1010
Functions: cat cut expr head tput

Same as original, but works in bash

while :; do integer i=0; COL=$((RANDOM%$(tput cols))); ROW=$((RANDOM%$(tput cols))); while (( i <= COL)) do tput cup $i $ROW; echo "\033[1;34m" $(cat /dev/urandom | head -1 | cut -c1-1) 2>/dev/null; i=$(expr $i + 1); done done
cat > <file_name> << "EOF"
2010-05-27 12:06:30
User: sphere64
Functions: cat

1. Issue command

2. After angled bracket appears, enter file contents

3. When done, type "EOF"