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

play high-res video files on a slow processor
Certain codecs in high res don't play so well on my Dell Mini 9. Using this command, I can play just about anything and it keeps the sound in sync to boot!

ls -qahlSr # list all files in size order - largest last
I find it useful, when cleaning up deleting unwanted files to make more space, to list in size order so I can delete the largest first. Note that using "q" shows files with non-printing characters in name. In this sample output (above), I found two copies of the same iso file both of which are immediate "delete candidates" for me.

Random numbers with Ruby
There's been a few times I've needed to create random numbers. Although I've done so in PERL, I've found Ruby is actually faster. This script generates 20 random "10" digit number NOT A RANDOM NUMBER. Replace 20 (1..20) with the amount of random numbers you need generated

Check the current price of Bitcoin in USD

find system's indianness

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"

Press ctrl+r in a bash shell and type a few letters of a previous command
In the sample output, I pressed ctrl+r and typed the letters las. I can't imagine how much typing this has saved me.

prints message in given argument on on center of screen
$ function echox { echo `tput cup $(($(tput lines))) $(( ($(tput cols) - $(echo "${#1}"))/2 ))`"$1"`tput cup $(tput lines) $(( $(tput cols)-1 ))`; } echox prints given argument on bottom line center screen in terminal $ function echoxy { echo `tput cup $(($(tput lines)/2)) $(( ($(tput cols) - $(echo "${#1}"))/2))`"$1"`tput cup $(tput lines) $(( $(tput cols)-1 ))`; } exhoxy prints given argument center screen $ function echos { echo `tput cup $(($(tput lines)-2)) $(($(tput cols)-$(echo ${#1})))&&tput sc`"$1"`tput cup $(($(tput lines)-2)) 0 && tput rc`; } $ while [ 1 ]; do echos "`date`"; done echos prints date and time on second from last line (used as status message) you can easily use these functions by placing them in your .bashrc file, make sure to source your .bashrc once you do

Generate Random Passwords
If you want a password length longer than 6, changing the -c6 to read -c8 will give you 8 random characters instead of 6. To end up with a line-feed, use this with echo: # echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6` Modern systems need higher strenght, so add some special characters: # < /dev/urandom tr -dc '12345!@#$%qwertQWERTasdfgASDFGzxcvbZXCVB' | head -c8

Retrofit a shebang to an existing script
Function to add a shebang to an existing script, handy if you forgot to add it in the first place.


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: