From: Jan Svitok <jan.svitok@...>
Date: 2007-01-12T05:30:05+09:00
Subject: Re: Finding path to ruby script argument

On 1/11/07, Matthew Hailstone <matthew.hailstone@gmail.com> wrote:
> Looks like __FILE__ and $0 are the same.

Not necessarily... when running a script under rcov or similar, they
may differ (for example one starts with ./ while the other does not).
That's why I write the if __FILE__ == $0 idiom as

if File.expand_path(__FILE__) == File.expand_path($0)

Another possibility might be is when you start the script using $PATH,
i.e. not from current directory, but without specifying its path.