grep alias with arguments and filter

alias mygrep 'grep -i -R \!^ * | grep -v \.svn'

(!^ passes the first argument)

(works only in cshell, for bash use something like this.)

skype on ubuntu gutsy amd64

install using AMD64 section of this HowTo.
(extract .deb packages using "-x", use LD_LIBRARY_PATH when starting skype.)

install webcam driver as described here. it is important to remove the old driver from its location.

encode png images to x264 avi

for i in `seq 1 3`; do mencoder mf://*.png -sws 10 -vf scale=800:592 -ovc x264 -x264encopts qp=40:subq=7:pass=$i -o output.avi; done

debug http web form url

Save the page to your local disk and change the method to a get instead of submit and you'll see the values in the addressbar.

even more useful: Live HTTP Headers Addon

apt-get changelog

Manually for each package:
aptitude changelog package-name

Automatically for each upgrade (and of course also manually):
sudo apt-get install apt-listchanges
sudo dpkg-reconfigure apt-listchanges

crop and rescale without blur

see examples here.

convert input.png -crop 128x128+571+569 +repage -scale 1024x1024 output.png

With geometry argument as described here.
(width x height +offset_x +offset_y)

The positions of the filenames are important!

rename mp3 files using track number

for id3v2 tags:

for i in *.mp3; do num=`id3v2 --list "$i" | grep TRCK | cut -f 2 -d:`; mv "$i" "`printf %02d $num` - $i"; done