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.


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.
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

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!
Hide

Top Tags

Hide

Functions

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

All commands from sorted by
Terminal - All commands - 12,403 results
alias whatismyip="wget -q -O - http://whatismyip.com/automation/n09230945.asp"
2009-10-30 15:42:52
User: gibboris
Functions: alias
-3

The preferred way for scripts (and easier to parse)

dh() { du -ch --max-depth=1 "${@-.}"|sort -h }
unzip -l <filename>
2009-10-30 12:21:06
User: tatwright
-8

This is useful for working out whether the file that you are unzipping is an evil zip file which will create 200 new files in your current direction

for URL in `wget -O - http://api.flickr.com/services/feeds/photos_public.gne?tags=bitch,bw 2>/dev/null | grep -E -o "http[^ ]+?jpg" | grep -v "_m" | uniq | grep -v 'buddy' `; do FILE=`echo $URL | grep -E -o "[0-9a-z_]+\.jpg"`; curl $URL > $FILE; done;
alias ..="cd .."; alias ...="cd ../.."; alias ....="cd ../../.."
2009-10-30 01:04:33
User: Tzunamii
Functions: alias
Tags: cd
1

Change to your taste. Much quicker than having to add 'cd' every time. Add it to your .bashrc or .bash_profile.

cd() { if [[ "$1" =~ ^\.\.+$ ]];then local a dir;a=${#1};while [ $a -ne 1 ];do dir=${dir}"../";((a--));done;builtin cd $dir;else builtin cd "$@";fi ;}
2009-10-29 21:43:51
User: eightmillion
Functions: cd
Tags: cd
4

This is a kind of wrapper around the shell builtin cd that allows a person to quickly go up several directories.

Instead of typing:

cd ../..

A user can type:

cd ...

Instead of:

cd ../../..

Type:

cd ....

Add another period and it goes up four levels. Adding more periods will take you up more levels.

cat > list -
2009-10-29 20:20:11
Functions: cat
3

Quick write some notes to a file with cat. Ctrl+C when you have finish.

nice -n19 dump -0af - /<filesystem> -z9|gpg -e -r <gpg key id>|cstream -v 1 -t 60k|ssh <[email protected]> "cat > backup.img"
2009-10-29 18:27:25
User: din7
Functions: dump gpg nice ssh
2

This command will nicely dump a filesystem to STDOUT, compress it, encrypt it with the gpg key of your choice, throttle the the data stream to 60kb/s and finally use ssh to copy the contents to an image on a remote machine.

newest () { candidate=''; for i in "$@"; do [[ -f $i ]] || continue; [[ -z $candidate || $i -nt $candidate ]] && candidate="$i"; done; echo "$candidate"; }
2009-10-29 17:35:01
User: johnraff
Functions: echo
Tags: bash files
1

Usage example:

newest Desktop/*

Replace "-nt" with "-ot" for oldest.

Run

shopt -s dotglob

first to include dotfiles.

sudo touch /forcefsck
2009-10-29 17:04:47
User: johnraff
Functions: sudo touch
37

The empty file /forcefsck causes the file system check fsck to be run next time you boot up, after which it will be removed.

This works too:

sudo >/forcefsck
find . -type f -size 0 -delete
2009-10-29 16:51:09
User: Skam
Functions: find
1

The command find search commands with size zero and erase them.

echo {001..5}
2009-10-29 16:25:44
User: nanard06
Functions: echo
Tags: bash
6

bash2 : for X in $(seq 1 5); do printf "%03g " "$X";done

bash3 : for X in {1..5}; do printf "%03g " "$X";done

bash4 : echo {001..5}

> [filename].txt
2009-10-29 16:20:35
User: felix001
0

empties a file...

--- fir3net.com ---

find . -size 0 -exec rm '{}' \;
<alt+q>
2009-10-29 14:55:12
User: luther
Tags: edit zsh
5

When writing on the command line of zsh, by pressing Alt+q the command will be cleaned, and you can insert another one. The command you were writing will be recorder, and pasted on the prompt immediately after the "interrupting" command is inserted.

find . -size 0 -print0 | xargs -0 rm
2009-10-29 14:10:02
User: osvaldofilho
Functions: find xargs
-1

The command find search commands with size zero and erase them.

mysql -u <user> --password=<password> -e "SHOW COLUMNS FROM <table>" <database> | awk '{print $1}' | tr "\n" "," | sed 's/,$//g'
2009-10-29 13:42:17
User: maxmanders
Functions: awk sed tr
-1

Useful when you need to write e.g. an INSERT for a table with a large number of columns. This command will retrieve the column names and comma-separate them ready for INSERT INTO(...), removing the last comma.

ps -eo user,pcpu,pmem | tail -n +2 | awk '{num[$1]++; cpu[$1] += $2; mem[$1] += $3} END{printf("NPROC\tUSER\tCPU\tMEM\n"); for (user in cpu) printf("%d\t%s\t%.2f\t%.2f\n",num[user], user, cpu[user], mem[user]) }'
2009-10-29 12:49:01
User: georgz
Functions: awk ps tail
7

The original version gives an error, here is the correct output

(crontab -e) 00 12 * * * apt-get update (/etc/init.d/cron restart)
find . -name '*.java' | xargs -L 1 cpp -fpreprocessed | grep . | wc -l
2009-10-29 09:58:43
User: rbossy
Functions: cpp find grep wc xargs
2

I took java to make the find command simpler and to state that it works for any language supported by cpp.

cpp is the C/C++ preprocessor (interprets macros, removes comments, inserts includes, resolves trigraphs). The -fpreprocessor option tells cpp to assume the input has already been preprocessed so it will only replace comment lines with blank lines.

The -L 1 option tells xargs to launch one process for each line, indeed cpp can only process one file at the time...

mysqldump -uUSERNAME -pPASSWORD database | gzip > /path/to/db/files/db-backup-`date +%Y-%m-%d`.sql.gz ;find /path/to/db/files/* -mtime +5 -exec rm {} \;
gcc -dM -E - <<<''
gcc -dM -E - < /dev/null
TIMEUNIT=$(awk '/timescale/{print NR}' a)
TIMEUNIT=$( cat a | grep -n "timescale" | awk -F ":" '{ print $1 } ' )