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

Create a single-use TCP proxy with copy to stdout
USAGE: gate listening_port host port Creates listening socket and connects to remote device at host:port. It uses pipes for connection between two sockets. Traffic which goes through pipes is wrote to stdout. I use it for debug network scripts.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Extract audio stream from an AVI file using mencoder
This commands saves the output in the audio directory. The portion ${file/%avi/mp3} uses bash string replacement to replace the avi to mp3 within the ${file} variable.

Dump the root directory to an external hard drive
This will compress the root directory to an external hard drive and split it to parts once it reaches the 4 Gigs file system limit. You can simply restore it with: $ restore ivf /media/My\ Passport/Fedora10bckup/root_dump_fedora

Display calendar with specific national holidays and week numbers
NB when you run this gcal command in your shell, holidays are highlighted but this highlighting does not show in the sample output (above). To find full details on gcal options: gcal --long-help | less Example for United States, Pennsylvania: gcal -K -q US_PA 2009 # display holidays in USA/Pennsylvania for 2009 (with week numbers) Example for Hong Kong: gcal -K -q HK 2009 # display holidays in Hong Kong for 2009 (with week numbers)

pngcrush all .png files in the directory
Find all pngs in directory structure and pngcrush them, none destructive. You can just remove the "{}.crush" part if you want destructive.

Report full partitions from a cron
Reports all local partitions having more than 90% usage. Just add it in a crontab and you'll get a mail when a disk is full. (sending mail to the root user must work for that)

Emergency Alien Invasion Warning
When aliens invade Earth, be first to warn your neighbours by placing your computer screen at a window and executing this potentially Earth-saving command. Ctrl C when aliens are defeated.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Remove old unused kernels from Red Hat Enterprise Linux 5 & Fedora 12/13
Install using yum install yum-utils Options include: --oldkernels Remove old kernel and kernel-devel packages --count=KERNELCOUNT Number of kernel packages to keep on the system (default 2) use package-cleanup --help for a complete list


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: