The title is optional. Options: -t: expire time in milliseconds. -u: urgency (low, normal, critical). -i: icon path. On Debian-based systems you may need to install the 'libnotify-bin' package. Useful to advise when a wget download or a simulation ends. Example: wget URL ; notify-send "Done"

'dpkg -S' just matches the string you supply it, so just using 'ls' as an argument matches any file from any package that has 'ls' anywhere in the filename. So usually it's a good idea to use an absolute path. You can see in the second example that 12 thousand files that are known to dpkg match the bare string 'ls'. Show Sample Output

Replace 'SHOWNAME' with the name of the TV show. Add -n to test the command without renaming files. Check the 'sample output'. Show Sample Output

Limits the usage of bandwidth by apt-get, in the example the command will use 30Kb/s ;) It should work for most apt-get actions (install, update, upgrade, dist-upgrade, etc.)

Ever since the switch to pulseaudio, Ubuntu users including myself have found themselves with no sound intermittently. To fix this, just use this command and restarts firefox or mplayer or whatever.

This command is useful when you want to install the same packages on another fresh OS install for example. To do that, use: sudo dpkg --set-selections < LIST_FILE Show Sample Output

Requires: imagemagick and graphviz On Debian systems, displays a graph of package dependencies. Works also with other image formats, like svg : apt-cache dotty bash | dot -T svg | display

Works similar to dpkg -S, but uses the locatedb and is thus inarguably a lot faster - if the locatedb is current.

Next time you are leaching off of someone else's wifi use this command before you start your bittorrent ...for legitimate files only of course. It creates a hexidecimal string using md5sum from the first few lines of /dev/urandom and splices it into the proper MAC address format. Then it changes your MAC and resets your wireless (wlan0:0). Show Sample Output

Show active calls as the happen on an Asterisk server. Note that the Asterisk command (in single quotes) is formatted for Asterisk 1.6. Use the -n flag on the watch command to modify the refresh period (in seconds - default is 2 seconds). Show Sample Output

Shows all configurations to apt and dpkg, rarely changed, you probably still have the default configuration. Go ahead and explore your configuration if you dare, perhaps change your apt-cache directory, Dir::Cache "var/cache/apt/"; or the names of the log files. Show Sample Output

This command will disable the beep sound from the PC speaker.

if you still get a permissions error using sudo, then nano the file: sudo nano -w /sys/block/sdb/queue/rotational and change 1 to 0 this thread: http://www.ocztechnologyforum.com/forum/showpost.php?p=369836&postcount=15 says that this will "help the block layer to optimize a few decisions"

this also generates errors (change 4 to higher number for more mistakes)

This will take the packages matching a given `apt-cache search` query (a collection of AND'd words or regexps) and tell you how popular they are. This is particularly nice for those times you have to figure out which solution to use for e.g. a PDF reader or a VNC client. Substitute "ubuntu.com" for "debian.org" if you want this to use Ubuntu's data instead. Everything else will work perfectly. Show Sample Output

On Debian systems, choose which command provides java. Works for all alternatives listed in /etc/alternatives.

This will remove all installed kernels on your debian based install, except the one you're currently using. From: http://tuxtweaks.com/2009/12/remove-old-kernels-in-ubuntu/comment-page-1/#comment-1590

Writes hybrid ISO directly to USB stick; replace /dev/sdb with USB device in question and the ISO image link with the link of your choice

Lists all installed kernels minus the current one. This is useful to uninstall older kernels that take too much space on /boot partition. Show Sample Output

Useful to e.g. keep an eye on several logfiles. Show Sample Output

Reconfigures time zone in Ubuntu, which I cannot figure out how to do through the GUI. Worked like a charm to set my time zone to CEST from EDT.

cd to the folder containing the wav files, then convert them all to flac. yeah baby! in ubuntu, to get the flac program just: sudo apt-get install flac flac file input formats are wav, aiff, raw, flac, oga and ogg Show Sample Output

Please install aria2c before you try the above command. On ubuntu the command to install aria2c would be: sudo aptitude install aria2

Sometimes, simpler is better.