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I'm always confused to get the version of software installed in Ubuntu. To prevent from full typing to get the version like <software> --version instead I always use some thing like <software> -V.

But the problem is that not for all software it works. For some I've to use <software> -v and for some I've to use full --version to get the version.

For example

wget, gedit, nano, mysql etc all works with -V (Capital V)

but Php, Skype and may be others never worked with -V instead I've to use -v (small v) to get the version:

php -V
Usage: php [options] [-f] <file> [--] [args...]
   php [options] -r <code> [--] [args...]
   php [options] [-B <begin_code>] -R <code> [-E <end_code>] [--] [args...]
   php [options] [-B <begin_code>] -F <file> [-E <end_code>] [--] [args...]
   ...

php -v
PHP 5.3.10-1ubuntu3.9 with Suhosin-Patch (cli) (built: Dec 12 2013 04:27:25) 
...

Some work with both -v and -V like firefox. And some even don't work with either of -v or -V like totem , wine and google-chrome.

  • Why there is this much difference?
  • Since -V is always preferred to get the version of software, Why there is no any standard? or is there any standard that I don't know?
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3 Answers 3

up vote 1 down vote accepted

The standard is:

app --version

-v or -V is only (not generally speaking) the abbreviated form for --version. You will never see in a man page something like:

-v
    Print version...

or:

-V
    Print version...

but you will see all the time these two options, the abbreviated form (if this exists) and the standard form, together. Something like:

-v, --version
    Print version...

or:

-V, --version
    Print version...

But this depends only by developers how they want to implement their applications. For example -v is used in some cases as the abbreviated form for --verbose (see man wget), or for --invert-match (see man grep) a.o., or in other cases as stand alone (see man awk or man ps).

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I'm always satisfied by your answer.. Thanks :) –  Saurav Kumar Jan 31 at 10:48

Those are verbose options related to each application so some apps used the -V others use -v others both or just --version. There is no general rule for naming convention.

what i mean to say is those options don't have a standard so you may find option -X in some app do the same as -R in other ...

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+1 for your time given to answer this question. But the answer which satisfied me most came from Radu Rădeanu, and you'll also agree with this. :) –  Saurav Kumar Jan 31 at 10:51

It typically ends up being caused by an option called "verbosity". Verbosity runs a program and prints as much information as possible to the terminal from which it was called.

Some programs, however, don't support verbose mode or don't run in a way that would require any form of verbosity, so they will spit out the help string. Others will treat -v and -V equally.

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