Tac and Rev to see files in reverse order

After many years of administration of Unix/Linux systems and using bash for many tasks i’ve discovered the command tac, the contrary of cat, What this command do it’s to concatenate and print files in reverse order, it writes each file to standard output, last line first. bash$ cat file1.txt This is the line 1. This [...]

How to mounts an archive for access as a file system

Sometimes it happen to have the need of check what’s inside a .tar.gz file archive or perhaps you just need to extract a couple of files from another archive, this is possible you just have to remember all the flags or simply extract all in /tmp and then discard the files that you don’t need. [...]

Tmux – the Terminal multiplexer

In a former article i’ve show how to use Screen and Byobu, in short Screen is a full-screen window manager that multiplexes a physical terminal between several processes (typically interactive shells) while Byobu is an elegant enhancement of the otherwise functional, plain, practical GNU Screen. Byobu includes an enhanced profile and configuration utilities for the [...]

Aliaser take control of your alias on Linux

Alias are a great tool to help increment your productivity on the terminal with bash (or any shell program you’re using), but usually we are too lazy to think at what are the most common, or long commands that we use frequently and prepare an alias for them. And so someone has done a small [...]

Guide to regular expressions with examples

The regular expression, or regexp, are the most powerful, versatile and hated tool used by programmers and system administrators. They allow to express with a few characters search for strings, characters or words, and if done well can lead to good results, but if they are wrong they can not give you any useful result, [...]