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

Count items in JSON array
Pipe any JSON to jq, then count with the appropiate expression and use the | length on the array

Convert (almost) any video file into webm format for online html5 streaming
If you're using the experimental vorbis encoder (homebrew version of libffmpeg)

Find the package that installed a command

Check syntax of all Perl modules or scripts underneath the current directory
Finds all *.p[ml]-files and runs a perl -c on them, checking whether Perl thinks they are syntactically correct

Show sections of a man page.
Uses the formatting of a man page to show an outline of its headers and sub-headers.

move messages directly from one IMAP inbox to another
This one-liner was useful in helping someone I know to get off of MS Exchange. `mailutil` proved to be a much better alternative than `fetchmail` or `getmail` in this case. It quickly moved all mails to the destination server (a simple Dovecot/Maildir setup), with no need to convert back and forth between mbox/maildir on the user's own system.

remove leading blank lines

Combine cssh and shell expansion to execute commands on a large cluster
This will open an awful lot of little windows, but is quite useful if you want to quickly patch something on a cluster of servers.

Quickly add user accounts to the system and force a password change on first login
This command is a bit Linux specific, as --stdin doesn't exist for passwd on many Unix machines. Further, useradd is high level in most distributions and Unix derivatives except for the Debian family of distros, where adduser would be more appropriate. The last bit, with chage, will force the user to change their password on new login.

Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously


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: