Sometimes, it is important to know what version of the program you are running.
These days as I develop Audax I need to check version numbers (among other things) quite regularly. Checking a version number is usually quite easy and gets to be done with a – -version suffix.

Note. There should not be a space between – – .

Below are some examples about the things that get printed to the terminal – once the – -version suffix is attached. The examples are from Audax 0.2. so the text output is likely to be a bit different if you use another distribution.

fluxbox – -version
Fluxbox 1.3.7 : (c) 2001-2015 Fluxbox Team

geany – -version
geany 1.22 (built on Jun 20 2012 with GTK 2.24.10, GLib 2.32.3)

irssi – -version
irssi 0.8.17 (20141011 1044)

firefox – -version
Mozilla Firefox 35.0.1

emelfm2 – -version
emelFM2 v. 0.9.1
Licensed under the GPL
Copyright (C) 2003-2015, tooar <tooar@emelfm2.net>
Build date: pe 27.2.2015 12.03.11 +0200
Build platform: GTK+ 2.24.10 Linux 3.14.33-audax/i686

For kernel use:

uname -a
Linux Audax 3.14.33-audax #1 SMP PREEMPT Tue Feb 17 19:46:44 EET 2015 i686 GNU/Linux

Some cases where version number is a good information to have

1. You are trying to build something from source code and you want to make sure it is worth it – and thus you check the version of the program you are currently running.

2.You are about to send a bug report. If you do send a bug report it must have version number attached with it. It is quite useless to report a bug when it is not clear what revision of a given program is affected by it.

3.  You maintain your own mirror of packages. It might be your private repository just for your industry or workplace or it might be an additional repository where you place your own adjustments that are not available in upstream.