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

All commands from sorted by
Terminal - All commands - 11,581 results
rm !(*.foo|*.bar|*.baz)
2010-04-13 15:13:54
User: hutch
Functions: rm
72

Deletes all files in a folder that are NOT *.foo, *.bar or *.baz files. Edit the pattern inside the brackets as you like.

ifconfig | convert label:@- ip.png
python -m smtpd -n -c DebuggingServer localhost:1025
2009-02-05 16:50:44
User: jemerick
Functions: python
68

This command will start a simple SMTP server listening on port 1025 of localhost. This server simply prints to standard output all email headers and the email body.

fuser -k filename
2009-02-05 20:16:11
User: fzero
Functions: fuser
66

Useful when you're trying to unmount a volume and other sticky situations where a rogue process is annoying the hell out of you.

man hier
2010-01-26 16:31:05
User: haivu
Functions: man
63

Curious about differences between /bin, /usr/bin, and /usr/local/bin? What should be in the /sbin dir? Try this command to find out.

Tested against Red Hat & OS X

awk '!x[$0]++' <file>
2009-12-20 02:33:21
User: din7
Functions: awk
63

Using awk, find duplicates in a file without sorting, which reorders the contents. awk will not reorder them, and still find and remove duplicates which you can then redirect into another file.

vim -x <FILENAME>
2009-05-05 23:24:17
User: denzuko
Functions: vim
63

While I love gpg and truecrypt there's some times when you just want to edit a file and not worry about keys or having to deal needing extra software on hand. Thus, you can use vim's encrypted file format.

For more info on vim's encrypted files visit: http://www.vim.org/htmldoc/editing.html#encryption

wget -qO - "http://www.tarball.com/tarball.gz" | tar zxvf -
cat /etc/issue
translate(){ wget -qO- "http://ajax.googleapis.com/ajax/services/language/translate?v=1.0&q=$1&langpair=$2|${3:-en}" | sed 's/.*"translatedText":"\([^"]*\)".*}/\1\n/'; }
2010-03-08 03:15:48
User: matthewbauer
Functions: sed wget
62

Usage:

translate <phrase> <source-language> <output-language>

Example:

translate hello en es

See this for a list of language codes:

http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

ps aux | grep [p]rocess-name
2009-08-13 05:44:45
User: olorin
Functions: grep ps
62

As an alternative to using an additional grep -v grep you can use a simple regular expression in the search pattern (first letter is something out of the single letter list ;-)) to drop the grep command itself.

!:-
2010-05-15 15:12:47
User: new_user
Tags: bash edit
61
/usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.google.com/

then

!:- http://www.commandlinefu.com/

is the same as

/usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.commandlinefu.com/
tr -c "[:digit:]" " " < /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]"
ssh-copy-id username@hostname
mplayer -ao pcm -vo null -vc dummy -dumpaudio -dumpfile <output-file> <input-file>
ESC *
2009-06-14 21:17:40
User: Josay
Tags: completion ESC
59

Pressing ESC then * will insert in the command line the results of the autocompletion.

It's hard to explain but if you look the sample output or do

echo ESC *

you will understand quickly.

By the way, few reminders about ESC :

- Hold ESC does the same thing as tab tab

- 'ESC .' inserts the last argument of last command (can be done many times in order to get the last argument of all previous commands)

? () { echo "$*" | bc -l; }
2009-06-28 20:15:30
User: fizz
Functions: bc echo
56

defines a handy function for quick calculations from cli.

once defined:

? 10*2+3
i="8uyxVmdaJ-w";mplayer -fs $(curl -s "http://www.youtube.com/get_video_info?&video_id=$i" | echo -e $(sed 's/%/\\x/g;s/.*\(v[0-9]\.lscache.*\)/http:\/\/\1/g') | grep -oP '^[^|,]*')
2009-03-09 03:57:44
User: lrvick
Functions: echo grep sed
56

This is the result of a several week venture without X. I found myself totally happy without X (and by extension without flash) and was able to do just about anything but watch YouTube videos... so this a the solution I came up with for that. I am sure this can be done better but this does indeed work... and tends to work far better than YouTube's ghetto proprietary flash player ;-)

Replace $i with any YouTube ID you want and this will scrape the site for the _real_ URL to the full quality .FLV file on Youtube's server and will then will hand that over to mplayer (or vlc or whatever you want) to be streamed.

In some browsers you can replace $i with just a % or put this in a shell script so all YouTube IDs can be handed directly off to your media player of choice for true streaming without the need for Flash or a downloader like clive. (I do however fully recommend clive if you wish to archive videos instead of streaming them)

If any interest is shown I would be more than happy to provide similar commands for other sites. Most streaming flash players use similar logic to YouTube.

Edit: 05/03/2011 -

Updated line to work with current YouTube. It could be a lot prettier but I will probably follow up with another update when I figure out how to get rid of that pesky Grep. Sed should take that syntax... but it doesn't.

Original (no longer working) command:

mplayer -fs $(echo "http://youtube.com/get_video.php?$(curl -s $youtube_url | sed -n "/watch_fullscreen/s;.*\(video_id.\+\)&title.*;\1;p")")

ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/ /' -e 's/-/|/'
2009-02-15 20:43:21
Functions: grep ls sed
53

Prints a graphical directory tree from your current directory

alias 'ps?'='ps ax | grep '
find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
2009-09-21 00:24:14
User: syssyphus
Functions: find md5sum sort uniq xargs
52

This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.

sed -n '10,20p' <filename>
2009-02-08 22:34:04
User: ergut
Functions: sed
52

Similarly, if you want to print from 10 to the end of line you can use: sed -n '10,$p' filename

This is especially useful if you are dealing with a large file. Sometimes you just want to extract a sample without opening the entire file.

Credit goes to wbx & robert at the comments section of http://www.commandlinefu.com/commands/view/348/get-line1000-from-text.#comment

strace -ff -e trace=write -e write=1,2 -p SOME_PID
readom dev=/dev/scd0 f=/path/to/image.iso
2009-03-08 13:21:23
User: atoponce
51

Many like to use 'dd' for creating CD/DVD iso images. This is bad. Very bad. The reason this is, is 'dd' doesn't have any built-in error checking. So, you don't know if you got all the bits or not. As such, it is not the right tool for the job. Instead, 'reaom' (read optical media) from the wodim package is what you should be using. It has built-in error checking. Similarly, if you want to burn your newly creating ISO, stay away from 'dd', and use:

wodim -v -eject /path/to/image.iso