Listing all available classes in ruby

I have to look further into the ObjectSpace module.

But this command lists all the available classes.

ObjectSpace.each_object(Class) {|c| p c}

You could also save all the results to an array, require your new module, call it again and subtract one set from another just to get the new classes from the library (If you're lacking documentation).

Fix unity after disabling in in Compiz

I thought I'd disable Unity in Compiz after a fresh install of Ubuntu 11.10. Alas, it's so ingrained in the system that it totally borks the UI. To fix this I created a terminal launcher on the desktop (as Ctrl-Alt-T and Alt-F2 didn't work any more) that looked like this:

#!/bin/sh   
gnome-terminal

Then selected the file's properties and set the execute bit to true. Then ran the file. This left me with an open terminal in which I then typed:

ccsm

This brought back unity and now the computer's back to a functional UI.

Now all I need to do is work out how to disable that damn sidebar that gets in the way more than it help...

Download the android source as a zip

Hmmm, the repo script doesn't appear to be working thanks to conflicting variables on the work set up. So to get a zip of the android source I went to http://rgruet.free.fr/public/ and downloaded the latest.

All the other google results were severely outdated.

compile kernel module from c file

make -C M=`pwd`
That is all. .ko sitting there:
As per line 61: http://lxr.linux.no/linux+v2.6.28.3/Documentation/kbuild/modules.txt

error: keyutils.h: No such file or directory ubuntu

Installing libkeyutils-dev solved the problem.

Quick capitalization

in Bash: ${VAR^}

How to grep for tab

cat example.txt | grep $'\t'