Querying a specific name server using dig

A practical tip on how to avoid cached results when looking up DNS records.

Adding a user to the sudoers list in Ubuntu

Stop using root for administrative tasks. Here is how to add a new user to the sudoers list in Ubuntu.

A more powerful version of grep

The utility command grep has a more powerful brother that let us use POSIX Extended Regular Expressions.

Display disk usage with the du command

How to display the total of the current directory or a particular directory, as well as listing subtotals (subdirectories).

Hide the desktop icons on Mac OS X

A two step way using the defaults command to hide the icons from the desktop in Mac OS X.