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

How to get an absolute value
Whenever we are only interested in difference between two numbers and not the positive/negative values we can use this in script.

Google URL shortener
use curl and sed to shorten an url via goo.gl

Find non ascii characters in files in folder

Get the full path of a bash script's Git repository head.
Rather than complicated and fragile paths relative to a script like "../../other", this command will retrieve the full path of the file's repository head. Safe with spaces in directory names. Works within a symlinked directory. Broken down: $cd "$(dirname "${BASH_SOURCE[0]}")" temporarily changes directories within this expansion. Double quoted "$(dirname" and ")" with unquoted ${BASH_SOURCE[0]} allows spaces in the path. $git rev-parse --show-toplevel gets the full path of the repository head of the current working directory, which was temporarily changed by the "cd".

Watch the progress of 'dd'
Running this code will execute dd in the background, and you'll grab the process ID with '$!' and assign it to the 'pid' variable. Now, you can watch the progress with the following: $ while true; do kill -USR1 $pid && sleep 1 && clear; done The important thing to grasp here isn't the filename or location of your input or output, or even the block size for that matter, but the fact that you can keep an eye on 'dd' as it's running to see where you are at during its execution.

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"

Check if *hardware* is 32bit or 64bit
This command tell you if your hardware is 32 or 64 bits even if you install a 32bits OS on a 64 bits hardware. If your distro don't support the -q switch, try doing : $ grep &>/dev/null '\' /proc/cpuinfo && echo 64 bits || echo 32 bits

Update a tarball
This will update the tarball, adding files that have changed since the last update. This assumes that the tarball is in the same directory as the files being archived. N.B. This command can't be used on compressed tarballs. N.B. This will add the updated files to the tarball, so that the tarball will have two versions of each file. This will make the tarball larger, but doesn't have any other significant effect.

Runs previous command replacing foo by bar every time that foo appears
Very useful for rerunning a long command changing some arguments globally. As opposed to ^foo^bar, which only replaces the first occurrence of foo, this one changes every occurrence.

search installed files of package, that doesn't remember his name well. On rpm systems
rpm, sometimes, is not wildcard friendly. To search files installed from package this could be useful. change PACKAGENAME to any package do you want to search


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: