Ricardo Altamirano's questions

I want to design a sudo rule that will allow the user ricardo to update the system using aptitude, but prevent him from using sudo to run any other command (he's a problem user). Are there any pitfalls to this rule that I'm missing?

ricardo  ALL=(root) /usr/bin/aptitude

Ricardo only uses aptitude, not apt-get. Also, I don't have Ubuntu installed anywhere at the moment, so I understand that /usr/bin/aptitude might not be the exact right file to allow.

If there are pitfalls to this rule, how can I improve it?

I was listening to music, and my sound suddenly went dead in all my applications. I'm using Ubuntu 12.04, which uses pulseaudio, so I tried sudo /etc/init.d/pulseaudio restart, but nothing happened. According to lsof | grep pcm, nothing is using the soundcard at the moment, although I'm not entirely sure if my source for that command is applicable.

Is there a way another way to restart Ubuntu 12.04's sound system from the command line without rebooting the system?

I installed the julius and julius-voxforge packages on Ubuntu 12.04 LTS, and now I'm trying to run the julius command on a WAV file called test.wav. I ran this command:

julius -input raw test.wav

but it simply says "Segmentation fault" without any further information. I've been searching the documentation for a few hours now, and I can't find any relevant information.

I'm trying to look at some statistics on the size of packages in the Ubuntu repositories, and I'm hoping to sort my searches of packages in the repositories by file size. Is there a command that will let me look at file sizes of packages in the repositories/cache, sort them by file size, etc? `apt-cache stats' doesn't provide all the information I'd like.

I'm interested in only the official repositories at the moment, and I'm interested in sorting all packages in the repositories, not simply the ones I have installed.