Commands by wu (2)

What's this? 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

Find the package that installed a command

perl insert character on the first line on your file

Open screen on the previous command
I often find myself wanting to open screen on whatever command I'm currently running. Unfortunately, opening a fresh screen session spawns a new bash session, which doesn't keep my history, so calling screen directly with the previous command is the only way to go.

Skip over .svn directories when using the "find" command.
The "find" command can be annoying when used inside of a Subversion (or CVS) working directory. Obviously, you can combine this with other predicates and commands to create a more elaborate pipeline: $ find /var/svn -type f -not \( -name .svn -prune \) -print0 | xargs -0 md5sum Note: You can use my "" script to wrap the "find" command and do this automatically at

Run the last command as root
Useful when you forget to use sudo for a command. "!!" grabs the last run command.

Add 10 random unrated songs to xmms2 playlist
If you're like me and want to keep all your music rated, and you use xmms2, you might like this command. I takes 10 random songs from your xmms2 library that don't have any rating, and adds them to your current playlist. You can then rate them in another xmms2 client that supports rating (I like kuechenstation). I'm pretty sure there's a better way to do the grep ... | sed ... part, probably with awk, but I don't know awk, so I'd welcome any suggestions.

turn off auto hard disc boot scanning for ext3

Send e-mail if host is 'dead' or not reachable
Cleaner with a mailto assignment in crontab (if the command fails you get an email): [email protected] 10,30,50 * * * * ping -q -c1 -w3 >/dev/null

Transfer SSH public key to another machine in one step
This command sequence allows simple setup of (gasp!) password-less SSH logins. Be careful, as if you already have an SSH keypair in your ~/.ssh directory on the local machine, there is a possibility ssh-keygen may overwrite them. ssh-copy-id copies the public key to the remote host and appends it to the remote account's ~/.ssh/authorized_keys file. When trying ssh, if you used no passphrase for your key, the remote shell appears soon after invoking ssh [email protected]

Show the number of current httpd processes

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.


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: