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

List open IPv4 connections

Multiple variable assignments from command output in BASH
This version uses read instead of eval.

Print a random 8 digit number
Don't need to pipe the output into rs if you just tell jot to use a null separator character.

Scans for open ports using telnet

Make info pages much less painful
The pinfo package makes info pages much more bearable. It is a ncurses-based POSIX utility for viewing info and man pages using lynx style keyboard shortcuts and rendering. Links are highlighted blue, the current location of your cursor is red. Navigating and searching are easy. Worth the install.

View acceptable client certificate CA names asked for during SSL renegotiations
The key is to use the -prexit option at the command line, and then type "quit" instead of CTRL-C to exit OpenSSL. OpenSSL will then dump its last negotiated state, printing out the contents of the renegotiated handshake. Crucial for debugging client certificate configurations on web servers such as IIS, which renegotiate the SSL/TLS connection with the HTTP request in-flight to ask the client for a cert.

Block all IP addresses and domains that have attempted brute force SSH login to computer
Searches all log files (including archived bzip2 files) for invalid user and PAM authentication errors, both of which are indicative of brute force attempts at logging into computer. A list of all unique IP addresses and domain names is appended to hosts.deny. The command (and grep error messages) will work on Mac OS X 10.6, small adjustments may be needed for other OSs.

Binary clock

scp with compression.
-C is for compression.

list block devices
Shows all block devices in a tree with descruptions of what they are.


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: