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

Read null character seperated fields from a file
Handle any bad named file which contains ",',\n,\b,\t,` etc Store the file name as null character separated list $find . -print0 >name.lst and retrieve it using $read -r -d "" Eg: $find . -print0 >name.lst; $cat name.lst| while IFS="" read -r -d "" file; $do $ls -l "$file"; $done

Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

View advanced Sort options, Quick Reference Help Alias
Once you get into advanced/optimized scripts, functions, or cli usage, you will use the sort command alot. The options are difficult to master/memorize however, and when you use sort commands as much as I do (some examples below), it's useful to have the help available with a simple alias. I love this alias as I never seem to remember all the options for sort, and I use sort like crazy (much better than uniq for example). # Sorts by file permissions $ find . -maxdepth 1 -printf '%.5m %10M %p\n' | sort -k1 -r -g -bS 20% 00761 drwxrw---x ./tmp 00755 drwxr-xr-x . 00701 drwx-----x ./askapache-m 00644 -rw-r--r-- ./.htaccess # Shows uniq history fast $ history 1000 | sed 's/^[0-9 ]*//' | sort -fubdS 50% exec bash -lxv export TERM=putty-256color Taken from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Colorized grep in less
Get your colorized grep output in less(1). This involves two things: forcing grep to output colors even though it's not going to a terminal and telling less to handle those properly.

Extract rpm package name, version and release using some fancy sed regex
This command could seem pretty pointless especially when you can get the same result more easily using the rpm builtin queryformat, like: $ rpm -qa --qf "%{NAME} %{VERSION} %{RELEASE}.%{ARCH}\n" | sort | column -t but nonetheless I've learned that sometimes it can be quite interesting trying to explore alternative ways to accomplish the same task (as Perl folks like to say: There's more than one way to do it!)

Count occurrences per minute in a log file
The cut should match the relevant timestamp part of the logfile, the uniq will count the number of occurrences during this time interval.

Detect Language of a string
Usage: $ detectlanguage Example: $ detectlanguage hola

Choose from a nice graphical menu which DI.FM radio station to play
This is a very simple and lightweight way to play DI.FM stations For a more complete version of the command with proper strings in the menu, try: (couldnt fit in the command field above) $zenity --list --width 500 --height 500 --title 'DI.FM' --text 'Pick a Radio' --column 'radio' --column 'url' --print-column 2 $(curl -s http://www.di.fm/ | awk -F '"' '/href="http:.*\.pls.*96k/ {print $2}' | sort | awk -F '/|\.' '{print $(NF-1) " " $0}') | xargs mplayer This command line parses the html returned from http://di.fm and display all radio stations in a nice graphical menu. After the radio is chosen, the url is passed to mplayer so the music can start dependencies: - x11 with gtk environment - zenity: simple app for displaying gtk menus (sudo apt-get install zenity on ubuntu) - mplayer: simple audio player (sudo apt-get install mplayer on ubuntu)

Find the package that installed a command

Visualizing system performance data


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: