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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.




All commands from sorted by
Terminal - All commands - 11,611 results
rename 'y/A-Z/a-z/' *
less =rcsyslog
echo *.log | xargs <command>
2009-02-22 11:32:55
User: mikeda
Functions: echo xargs
grep ERROR *.log

-bash: /bin/grep: Argument list too long

echo *.log | xargs grep ERROR /dev/null

20090119.00011.log:DANGEROUS ERROR

read VAR1 VAR2 VAR3 < <(echo aa bb cc); echo $VAR2
ARRAY=(aa bb cc);echo ${ARRAY[1]}
history -r
2009-02-22 01:24:14
User: Fate
Functions: reset

after a terminal gets clobbered (like after you cat a binary file by accident), this is the only way to get it back without re-starting it.

diff3 -a file1 file2 file3
2009-02-21 21:52:46
User: JollyJumper
Functions: diff3

It takes a hunk and shows the different between the three file. Useful when you want to compare two different changed file which from the same base file.

(use emacs ediff3, eyecandy and more useful if you want to merge them from anywhere to anywhere)

setfacl -m u:john:r-- myfile
2009-02-21 21:05:45
User: betsubetsu

The file myfile is owned by tom and has read and write permissions for tom. Group and other permissions are empty which make myfile readable and writable only by tom. setfacl enables user tom to give read permission to user john only. The command 'ls -l' shows a '+' sign telling us that file access control list has been setup for myfile.

function encode4phone() { ffmpeg -acodec libamr_nb -vcodec h263 -i "$1" -s qcif -b 200k -ac 1 -ab 7.4k -ar 8000 "$1.3gp" }
grep --color=auto -iRnH "$search_word" $directory
2009-02-21 19:16:33
User: tobiasboon
Functions: grep

greps for search word in directory and below (defaults to cd).

-i case insensitive

-n shows line number

-H shows file name

FILE="`date +%m%d%H%M%S`.png"; URL="http://YOUR_HOST/YOUR/PATH/$FILE"; TMP="/tmp/$FILE"; import -frame $TMP; scp $TMP YOUR-USER@YOUR-HOST:/YOUR/PATH/; rm $TMP; firefox "$URL"
2009-02-21 18:42:33
User: TheBunman
Functions: rm scp

I often need to send screenshots to other people to explain settings and whatever.

So I created this oneline which I use to create the screenshot with imagemagik, upload it via scp to my server and then the command opens an firefox tab with the screenshot.

The screenshot can be a region or a window.

You just have to replace the parts beginning with YOUR.

date -d '2 weeks ago Saturday' +%Y-%m-%d
2009-02-21 16:42:52
User: NPH
Functions: date

Good for automating reports that need to run from between two dates.

sed -e "s/| /\n/g" ~/.bash_history | cut -d ' ' -f 1 | sort | uniq -c | sort -nr | head
ssh -A user@somehost
2009-02-21 16:01:36
User: f4nt
Functions: ssh

the -A argument forwards your ssh private keys to the host you're going to. Useful in some scenarios where you have to hop to one server, and then login to another using a private key.

find /path/to/files -type f -mtime +7 | grep -v \.gz | xargs gzip
echo -en "stats\r\n" "quit\r\n" | nc localhost 11211 | tr -s [:cntrl:] " "| cut -f42,48 -d" " | sed "s/\([0-9]*\)\s\([0-9]*\)/ \2\/\1*100/" | bc -l
for x in `psql -e\l | awk '{print $1}'| egrep -v "(^List|^Name|\-\-\-\-\-|^\()"`; do pg_dump -C $x | gzip > /var/lib/pgsql/backups/$x-nightly.dmp.gz; done
2009-02-21 15:21:09
User: f4nt
Functions: awk egrep gzip

Ran as the postgres user, dumps each database individually. It dumps with the create statements as well, so you can just 'zcat $x-nightly.dmp.gz | psql' to reimport/recreate a database from a backup.

find . -type f -mtime +7 -exec ls -l {} \;
2009-02-21 08:03:24
User: senses0
Functions: find ls

Find files that are older than x days in the working directory and list them. This will recurse all the sub-directories inside the working directory.

By changing the value for -mtime, you can adjust the time and by replacing the ls command with, say, rm, you can remove those files if you wish to.

N="filepath" ; P=/proc/$(lsof +L1 | grep "$N" | awk '{print $2}')/fd ; ls -l $P | sed -rn "/$N/s/.*([0-9]+) ->.*/\1/p" | xargs -I_ cat $P/_ > "$N"
2009-02-21 02:31:24
User: laburu
Functions: awk cat grep ls sed xargs

Note that the file at the given path will have the contents of the (still) deleted file, but it is a new file with a new node number; in other words, this restores the data, but it does not actually "undelete" the old file.

I posted a function declaration encapsulating this functionality to http://www.reddit.com/r/programming/comments/7yx6f/how_to_undelete_any_open_deleted_file_in_linux/c07sqwe (please excuse the crap formatting).

doloop() { DONT=/tmp/do-run-run-run; while true; do touch $DONT; (sleep 30; rm $DONT;) & $1 ; if [ -e $DONT ]; then echo restarting too fast; return ; fi ; done }
2009-02-21 02:11:18
User: evil_otto
Functions: echo return rm sleep touch

This runs a command continuously, restarting it if it exits. Sort of a poor man's daemontools. Useful for running servers from the command line instead of inittab.

"some line input" | sort | uniq -c | sort -nr
for i in `ps aux | grep ssh | grep -v grep | awk {'print $2'}` ; do kill $i; done
a() { alias $1=cd\ $PWD; }
2009-02-21 01:53:01
Functions: alias

An easy way to create aliases for moving between many directories