Development Tools Here you can find all the posts in the Development Tools category. 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). SSH client configuration - Multiple servers and different keys If you just like me daily connect to multiple SSH servers, then I have a tip for you. Display line numbers using the cat command A simple feature you one day may be glad you know. Make apt-get assume yes as the answer to prompts during package installations The way to avoid prompts when dealing with the APT package handling utility in Ubuntu Server. Create and extract tar archives compressed with gzip For some reason I always find it hard to remember how to create and extract gzipped TAR archives, but here is how to do it.