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

df without line wrap on long FS name

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

resolve short urls
since the most url shorteners respond with a header containing the Location: ... this works with most common shorteners

Binary Clock
Binary clock with separate H:M:S.

Removing images by size
Removes all png files whose geometry is not 280x190 pixels

List files older than one year, exluding those in the .snapshot directory
Useful when you want to cron a daily deletion task in order to keep files not older than one year. The command excludes .snapshot directory to prevent backup deletion. One can append -delete to this command to delete the files : $ find /path/to/directory -not \( -name .snapshot -prune \) -type f -mtime +365 -delete

Anti DDOS
Takes IP from web logs and pipes to iptables, use grep to white list IPs.. use if a particular file is getting requested by many different addresses. Sure, its already down pipe and you bandwidth may suffer but that isnt the concern. This one liner saved me from all the traffic hitting the server a second time, reconfigure your system so your system will work like blog-post-1.php or the similar so legitimate users can continue working while the botnet kills itself.

A DESTRUCTIVE command to render a drive unbootable
THIS COMMAND IS DESTRUCTIVE. That said, lets assume you want to render your boot drive unbootable and reboot your machine. Maybe you want it to boot off the network and kickstart from a boot server for a fresh OS install. Replace /dev/fd0 with the device name of your boot drive and this DESTRUCTIVE command will render your drive unbootable. Your BIOS boot priority should be set to boot from HD first, then LAN.

List .log files open by a pid
Uses lsof to display the full path of ".log" files opened by a specified PID.

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"


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: