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

pretend to be busy in office to enjoy a cup of coffee
This will turn it in an infinite loop and also shows random words from a file, so it won't be the same each time and also not just a number.

analyze traffic remotely over ssh w/ wireshark
Please check out my blog article on this for more detail. http://jdubb.net/blog/2009/08/07/monitor-wireshark-capture-real-time-on-remote-host-via-ssh/

Detect if we are running on a VMware virtual machine
If you run this command on a VMWare Virtual Machine, it will return the string "VMware Virtual Platform". If you run it on a physical machine, it will return nothing. Useful for having a script determine if it's running on a VM or not. Of course, you must have dmidecode installed for this to work. Try it this way in a script: ISVM=$(dmidecode | awk '/VMware Virtual Platform/ {print $3,$4,$5}') Then test if $ISVM has text in it, or is blank.

connects to a serial console
cu (call UNIX) establishes a full-duplex connection to another machine (*BSD) using a serial console. It becames more useful than screen if you have to send a BREAK signal. using cu just type "~#". $man cu http://www.openbsd.org/cgi-bin/man.cgi?query=cu&apropos=0&sektion=0&manpath=OpenBSD+Current&arch=i386&format=html

Extract the contents of an RPM package to your current directory without installing them.
This assumes you have the 'rpm', 'rpm2cpio' and 'cpio' packages installed. This will extract the contents of the RPM package to your current directory. This is useful for working with the files that the package provides without installing the package on your system. Might be useful to create a temporary directory to hold the packages before running the extraction: $ mkdir /tmp/new-package/; cd /tmp/new-package

Get IP address from domain
shorter (thus better ;-)

Create a 5 MB blank file
Useful for testing purposes

True Random Dice Roll
/dev/urandom is cryptographically secure, and indistinguishable from true random, as it gathers data from external sources, influenced by human timing interactions with computers, to fill the entropy pool, and hashes the input with SHA-1. As such, this is a quick way to do a "true random" fair-6 dice roll. Using this method, you could easily create passphrases with Diceware http://diceware.com. Change the head(1) count to something other than 5 for more or less numbers.

Block all IPv4 addresses that has brute forcing our ssh server
For ipv6 use: grep -oE "\b([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4}\b"

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: