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

Convert decimal numbers to binary
Convert some decimal numbers to binary numbers. You could also build a general base-converter: $ function convBase { echo "ibase=$1; obase=$2; $3" | bc; } then you could write $ function decToBun { convBase 10 2 $1; }

Check a server is up. If it isn't mail me.
Alternative to the ping check if your firewall blocks ping. Uses curl to get the landing page silently, or fail with an error code. You can probably do this with wget as well.

Find the package that installed a command

Keep one instance of an irc chat client in a screen session
This command attempts to attach to existing irssi session, if one exists, otherwise creates one. I use "irc" because I use different irc clients depending on what system I am working on. Consistency is queen.

separate (emphasize) digital strings from other text

Generat a Random MAC address

Find unused IPs on a given subnet
Somewhat shorter version.

Annotate tail -f with timestamps
Uses the command ts in order to add a timestamp on each line. This command is provided in the moreutils package on Debian, and you may need libtime-duration-perl to be able to format the date.

grep apache access.log and list IP's by hits and date - sorted

Exclude inserting a table from a sql import
Starting with a large MySQL dump file (*.sql) remove any lines that have inserts for the specified table. Sometimes one or two tables are very large and uneeded, eg. log tables. To exclude multiple tables you can get fancy with sed, or just run the command again on subsequently generated files.


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: