All commands (14,187)

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. 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.

Share Your Commands


Check These Out

Directory bookmarks
pushd and popd are your friends, but sometimes they're just incompatible with the way one works... Two shell functions: bm bookmarkname - "bookmarks" the current directory, just 'cd $BMbookmarkname' to return to it. forget bookmarkname - unsets the 'bookmarkname' variable. It isn't mandatory, they cease to exist when the session ends.

count how many cat processes are running
'ps ax' provides the fill list of running processes. 'grep -c [c]at' will find all processes that match 'cat' without matching itself....

Split a tarball into multiple parts
Create a tar file in multiple parts if it's to large for a single disk, your filesystem, etc. Rejoin later with `cat .tar.*|tar xf -`

Get HTTP status code with curl AND print response on new line

Create a bunch of dummy text files

Keep from having to adjust your volume constantly
Run this in the directory you store your music in. mp3gain and vorbisgain applies the ReplayGain normalization routine to mp3 and ogg files (respectively) in a reversible way. ReplayGain uses psychoacoustic analysis to make all files sound about the same loudness, so you don't get knocked out of your chair by loud songs after cranking up the volume on quieter ones.

Redirect a filehandle from a currently running process.
This command uses the debugger to attach to a running process, and reassign a filehandle to a file. The two commands executed in gdb are p close(1) which closes STDOUT and p creat("/tmp/filename",0600) which creates a file and opens it for output. Since file handles are assigned sequentially, this command opens the file in place of STDOUT and once the process continues, new output to STDOUT will instead be written to our capture file.

Create a backup of the file.
It will create a backup of the filename. The advantage is that if you list the folder the backups will be sorted by date. The command works on any unix in bash.

statistics in one line
In this example, file contains five columns where first column is text. Variance is calculated for columns 2 - 5 by using perl module Statistics::Descriptive. There are many more statistical functions available in the module.

Updating the status on identi.ca using curl.
identica is an open source social networking and micro-blogging service. Based on Laconica, a micro-blogging software package built on the OpenMicroBlogging specification. http://identi.ca/


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: