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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 - 11,604 results
tput rmam
2014-02-26 07:06:37
User: kennyld
Functions: tput
Tags: bash ksh
tput rmam

will disable line wrapping so that long lines are truncated to width of the terminal ($COLUMNS).

tput smam

will re-enable wrapping.

I've always used tput in bash scripts but I guess it works on the command line too.

Doesn't work in all terminals.

See http://www.gnu.org/software/termutils/manual/termutils-2.0/html_chapter/tput_1.html

find . -type d| while read i; do echo $(ls -1 "$i"|wc -m) $(du -s "$i"); done|sort -s -n -k1,1 -k2,2 |awk -F'[ \t]+' '{ idx=$1$2; if (array[idx] == 1) {print} else if (array[idx]) {print array[idx]; print; array[idx]=1} else {array[idx]=$0}}'
2014-02-25 22:50:09
User: knoppix5
Functions: awk du echo find ls read sort wc

Very quick! Based only on the content sizes and the character counts of filenames. If both numbers are equal then two (or more) directories seem to be most likely identical.

if in doubt apply:

diff -rq path_to_dir1 path_to_dir2

AWK function taken from here:


cat cachedump.txt | awk -F : '{print $2":"$1}'
ssh -NL 12345:localhost:631 username@remote_server
catmandu convert JSON to YAML < file.json > file.yaml
2014-02-25 08:27:05

You need to install the Catmandu Perl module via `cpanm Catmandu`

printf -- " -e %s" ${ARRAY[*]}
2014-02-25 03:34:12
User: SEJeff
Functions: printf

[jeff@omniscience container] (master)$ echo docker run $(printf -- " -e %s" ${DOCKER_APP_VARS[*]}) -name 12factorapp mattdm/fedora-small

docker run -e DATABASE_USER=dbuserro, -e DATABASE_PASSWORD=maipass -name 12factorapp mattdm/fedora-small

Note that the printf method by itsself doesn't include a newline (\n), so you'll need to embed it into an echo statement or something that does.

edrv() { N=${1:-edrv}; truncate -s ${2:-256m} $N.img && L=$(losetup -f) && losetup $L $N.img && cryptsetup luksFormat --batch-mode $L && cryptsetup luksOpen $L $N && mkfs.vfat /dev/mapper/$N -n $N; cryptsetup luksClose $N; echo losetup -d $L to unmount; }
2014-02-24 01:38:21
User: snipertyler
Functions: echo losetup

You need to be root to do this. So check the command before running it.

You enter the same password for

Enter LUKS passphrase:

Verify passphrase:

Enter passphrase for /dev/loopn:


You can then copy the .img file to somewhere else.

Loop it it with losetup -f IMAGENAME.img and then mount it with a file manager (eg nemo) or run mount /dev/loopn /media/mountfolder

Acts similar to a mounted flash drive

watch -d -n 2 iptables -nvL
2014-02-23 16:35:03
User: xxdesmus
Functions: iptables watch

This will highlight (with a box over it) any changes since the last refresh.

ps -eo pmem,comm | grep application-name
2014-02-23 13:21:29
User: Darkstar
Functions: grep ps

Displays memory usage for individual instances of an application that spawns multiple instances of itself. This command also works on single process applications.

alias ...="awk '{fflush(); printf \".\"}' && echo \"\""
2014-02-22 22:20:22
User: lgarron
Functions: alias

If you're running a command with a lot of output, this serves as a simple progress indicator.

This avoids the need to use `/dev/null` for silencing. It works for any command that outputs lines, updates live (`fflush` avoids buffering), and is simple to understand.

sed -i '1iI am a new line' file.txt
2014-02-22 14:36:57
User: bbates
Functions: sed

You can use \n in your inserted data to insert multiple lines.

The leading number is the position in the file where you want the insert, so in this case a '1' indicates the top of the file.

$(eval "echo {${min}..${max}}")
echo "select a, b, c from table where a = 3;"| python -c "import sys;import sqlparse;print sqlparse.format(sys.stdin.read(), reindent=True, keyword_case='upper')"
2014-02-21 23:17:15
User: hide1713
Functions: echo python

You need to apt-get install python-sqlparse. This command simply formats a sql query and prints it out. It is very useful when you want to move a sql query from commandline to a shell script. Everything is done locally, so you don't need to worry about copying sql query to external websites.

cp filename{,.`date +%Y%m%d-%H%M%S`}
2014-02-21 10:21:28
User: techtonik
Functions: cp

This inserts timestamp instead of .bak extension.

echo -n text | hexdump -C
2014-02-21 09:15:15
User: Tomofumi
Functions: echo hexdump
Tags: sed hex ascii

hexdump could be used for conversion too!

apt-get update -y && apt-get upgrade -y && apt-get dist-upgrade -y && apt-get autoremove -y && apt-get autoclean -y
echo -n "string" | md5sum|cut -f 1 -d " "
2014-02-20 22:44:00
User: labadf
Functions: cut echo

echo defaults to include a newline character at the end of the string, which messes with the hash. If you suppress it with -n then it has the same effect as PHP's ?echo md5("string"), "\t-";? Even more, by using cut you get the exact same output, so it works as a drop-in replacement for the original command for this thread.

unzip -p doc.odt content.xml | sed 's|<[^>]*>| |g' | wc -l
sudo lsof -i -n -P | grep TCP
ab -n 1000 -c 100
2014-02-18 09:32:01
User: ynedelchev

This command will execute 1000 requests to the http URL handlink 100 concurent connections at a time. Then it will display statistics about the time that have been taken.

udevadm info -q all -n /dev/sdb | grep ID_PATH | cut -d'-' -f 2 | xargs -n 1 lspci -s
echo "Memory:" $(dmidecode --type memory | grep " MB" | awk '{sum += $2; a=sum/1024} END {print a}') "GB"
(read -r passphrase; b58encode 80$( brainwallet_exponent "$passphrase" )$( brainwallet_checksum "$passphrase" ))

A bitcoin "brainwallet" is a secret passphrase you carry in the "wallet" of your brain.

The Bitcoin Brainwallet Private Key Calculator calculates the standard base58 encoded bitcoin private key from your "brainwallet" passphrase.

The private key is the most important bitcoin number. All other numbers can be derived from it.

This command uses 3 other functions - all 3 are defined on my user page:

1) brainwallet_exponent() - search for Bitcoin Brainwallet Exponent Calculator

2) brainwallet_checksum() - search for Bitcoin Brainwallet Exponent Calculator

3) b58encode() - search for Bitcoin Brainwallet Base58 Encoder

Do make sure you use really strong, unpredictable passphrases (30+ characters)!

http:brainwallet.org can be used to check the accuracy of this calculator.

function b58encode () { local b58_lookup_table=({1..9} {A..H} {J..N} {P..Z} {a..k} {m..z}); bc<<<"obase=58;ibase=16;${1^^}"|(read -a s; for b58_index in "${s[@]}" ; do printf %s ${b58_lookup_table[ 10#"$b58_index" ]}; done); }

A bitcoin "brainwallet" is a secret passphrase you carry in your brain.

The Bitcoin Brainwallet Private Key Base58 Encoder is the third of three functions needed to calculate a bitcoin PRIVATE key from your "brainwallet" passphrase.

This base58 encoder uses the obase parameter of the amazing bc utility to convert from ASCII-hex to base58. Tech note: bc inserts line continuation backslashes, but the "read s" command automatically strips them out.

I hope that one day base58 will, like base64, be added to the amazing openssl utility.

function brainwallet_checksum () { (o='openssl sha256 -binary'; p='printf';($p %b "\x80";$p %s "$1"|$o)|$o|sha256sum|cut -b1-8); }

A bitcoin "brainwallet" is a secret passphrase you carry in your brain.

The Bitcoin Brainwallet Exponent Calculator is the second of three functions needed to calculate a bitcoin PRIVATE key. Roughly, checksum is the first 8 hex digits of sha256(sha256(0x80+sha256(passphrase)))

Note that this is a bash function, which means you have to type its name to invoke it