From command line, how to know which Firefox version is installed in windows/linux?

Question

I need to know which Firefox version is installed on my system from command line of Windows or Linux.

Answer 1

According to this link, it seems that the -v argument (and more) is broken on Windows. If you follow the bug link on the site, it seems there is a workaround. I quote the comment:

Workaround (works with Firefox, Thunderbird, and, I suppose, other programs too):

 -h | more

The bug happens because, without redirection, the program releases its stdout before handling the -help parameter. With redirection, stdout is not released and you can see the output.

So for example for Firefox:

C:\Program Files (x86)\Mozilla Firefox>firefox -v | more
Mozilla Firefox 3.6.13, Copyright (c) 1998 - 2010 mozilla.org

It works for me at least. Without | more I get nothing printed. On Linux it works with or without the piping.