Generate pink noise under ubuntu

Pink noise is useful to drown out distracting noises that surround you. In that way it can help your concentration. A simple program that ships with Ubuntu that generates pink noise is speaker-test. It comes with the package alsa-utils.

Difference between apt-get upgrade and apt-get dist-upgrade

Imagine you have installed packages A-1.deb and B-1.deb A-1.deb depends on packages Adep1-1.deb and Adep2-1.deb while B-1.deb depends on package Bdep1-1.deb: A-1.deb | `—– Adep1-1.deb `—– Adep2-1.deb B-1.deb | `—— Bdep1-1.deb Now, there is a new package available for program A, namely A-2.deb. A-2.deb still depends on Adep1-1.deb but now it also depends on a

Restrict ssh login to only certain users

To allow only certain users to login through ssh add the following to /etc/ssh/sshd_config: AllowUsers user1 user2 user3 where user1, user2 and user3 are the user’s login names.

Bridged networking with virtualbox, ubuntu and static ips

This is a little howto where I explain how I configured bridged networking for virtualbox with static ips on an Ubuntu host in order to make the virtual machine accessible from outside the host system. sudo aptitude install bridge-utils uml-utilities sudo adduser $USER uml-net Login again so the change takes effect. Modify /etc/network/interfaces so it

Spanish mental addition mp3

In another post I wrote how to create with festival, lame and sox an mp3 to practice mental addition. That mp3 used festival’s default english voice. What I did to have a spanish version is the following: Copy the text2wave script to ~/bin/ mkdir ~/bin cp $(which text2wave) ~/bin/text2wavees Add the following after line 46