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

check open ports without netstat or lsof

Recursively scan directories for mp3s and pass them to mplayer
The command first deletes any old playlist calles playlist.tmp under /tmp. After that it recursively searches all direcotries under ~/mp3 and stores the result in /tmp/playlist.tmp. After havin created the playlist, the command will execute mplayer which will shuffle through the playlist. This command is aliased to m is aliased to `rm -rf /tmp/playlist.tmp && find ~/mp3 -name *.mp3 > /tmp/playlist.tmp && mplayer -playlist /tmp/playlist.tmp -shuffle -loop 0 | grep Playing' in my ~/.bashrc.

openssl Generate Self Signed SSL Certifcate
generating self signed ssl certificate to use in dovecot postfix nginx Self signed certificates can be used for private encryptions between server and client and must be manually accepted on browser/ client

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Command to logout all the users in one command
Logs all users out except root. I changed the grep to use a regexp in case a user's username contained the word root.

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"

Mount proc
Run this in / in a chroot to get your own proc there.

Print CPU load in percent
Faster then all other commands here at cmdlinefu with the same purpose.

Replace multiple file extensions with a single extension
The above is just a prove of concept based around the nested bash substitution. This could be useful in situations where you're in a directory with many filetypes but you only want to convert a few. $ for f in *.bmp *.jpg *.tga; do convert $f ${f%.*}.png; done or you can use ls | egrep to get more specific... but be warned, files with spaces will cause a ruckus with expansion but the bash for loop uses a space delimited list. $ for f in $(ls | egrep "bmp$|jpg$|tga$"); do convert $f ${f%.*}.png; done I'm guessing some people will still prefer doing it the sed way but I thought the concept of this one was pretty neat. It will help me remember bash substitutions a little better :-P

Spawn a retro style terminal emulator.
Just note that ctrl+shift+t to make new tabs will not work with . Pair it with a terminal multiplexer like for the best experience.


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: