How to get exit status from a piped command in Linux shell

It’s funny how through small daily tasks sometimes it happen to find new features or commands that you do not knew not, and today this thing happened to me. In particular, I had to do something trivial on the shell of a server, run : command1 | tail-n 2 i use tail to keep, from [...]

Top Ten articles for Linuxaria in 2011

The first days of the new year are a good moment to look back at the past year and see what have been the most read articles of the site, this is also a good opportunity for you to read (or re-read) them. And, a bit late, but i wish you all a Happy New [...]

Doing calculations using bash

Sometimes in my small shell script i’ve to do some math, usually nothing too complex but it’s useful to do the math inside the bash script. Bash it’s really complete and among the many builtin functions there are also some mathematical functions. Using the syntax $((expression)) you can evaluate the expression. Operations allowed are quite [...]

Bash and I – The Bourne-Again SHell

by Frank Harris-Smith Bash has been around since pre-historic times, at least before GNU/Linux’s first release in 1991. My first personal encounter with Bash was in 1993. This was two years before Microsoft Windows 95 was released and Windows 3.1 was just a bad joke. The Software Development Company I was working for was using [...]

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 [...]