From: Stefano Crocco <stefano.crocco@...>
Date: 2008-09-25T20:52:05+09:00
Subject: Re: Invocation of ruby interpreter for .rb files under bash

Alle Thursday 25 September 2008, Zouplaz ha scritto:
> Hello, this is not really related to the core language by itself but I
> don't remember how to have the interpreter launched when typing foo.rb
> or foo (if foo is the name of the script) under bash ?
>
> I remember that I have to put something like
> #! /usr/ruby
>
> at the beginnin of the script but I don't remember the right syntax and
> didn't found a Google way to express it.
>
>
>
> Thanks

You're almost there. It's #! followed by a space then the path of the ruby 
executable:

#! /usr/bin/ruby

Another option is this:

#! /usr/bin/env ruby

This way, you don't need to know the position of the ruby executable, but only 
of the env executable (which, I suppose, should be more standard). The 
downside is that, at least with bash, you can't pass options to ruby. For 
example, the line

#! /usr/bin/env ruby -w

tries to get from env the path of the program ruby -w. Since ruby -w is not a 
program, you get an error.

In the first way, instead, you can pass options to ruby:

#! /usr/bin/ruby -w

Stefano