From: Robert Klemme <shortcutter@...>
Date: 2009-03-04T02:34:00+09:00
Subject: Re: expanding environment variable

On 03.03.2009 15:58, Daniel Schoch wrote:
> Dominik Honnef wrote:
>> On [Tue, 03.03.2009 23:28], Daniel Schoch wrote:
>>> Hi,
>>>
>>> I have a string
>>> s = "$DIR/test/$FILE"
>>>
>>> Is there an easy way to expand this with the defined environment
>>> variables?
>> What do you mean by environment variables? The stuff in ENV, or the
>> constants like __FILE__ or simply global variables?
> 
> I mean the stuff in ENV.
> SHELL:
> export DIR=x
> export FILE=y.z
> 
> RUBY:
> I'd like to know the easiest way from
>  s = "$DIR/test/$FILE"
> to
>  s = "x/test/y.z"

Just wondering: is there anything that would prevent doing this:

s = "#{ENV["DIR"]/test/#{ENV["FILE"]}"

or even

s = File.join ENV["DIR"], "test", ENV["FILE"]

?  In other words: is the format of your original string mandatory?  If 
not, I'd rather choose one of the other approaches.

Kind regards

	robert