Add a new user:
sudo adduser <username>
Add user to sudoers list:
sudo usermod -a -G sudo <username>
Purge all packages that match some criteria:
apt-get --purge remove postgresql*
Fixing remote locale - first add this to your ~/.bash_profile:
export LANGUAGE="en"
export LANG="C"
export LC_MESSAGES="C"
export LC_ALL="en_US.UTF-8"
Then run:
sudo locale-gen en_US en_US.UTF-8
sudo dpkg-reconfigure locales
Change timezone (check with date):
sudo ln -sf /usr/share/zoneinfo/US/Pacific /etc/localtime
Install a specific version of a package:
sudo apt-get install apache2=2.2.20-1ubuntu1