From: Robert Klemme <shortcutter@...>
Date: 2010-05-15T18:30:06+09:00
Subject: Re: difference between $0 and __FILE__

On 15.05.2010 10:33, Une Bévue wrote:
>
> i have a script in my HOME/bin :
>
> /Users/yt/bin/path_test.rb
>
> my "HOME/bin" is in the PATH
>
> then, if from this script, i outputs $0 and __FILE__
>
> with :
>
> path_test.rb  i got :
> $0 = /Users/yt/bin/path_test.rb
> __FILE__ = /Users/yt/bin/path_test.rb
>
>
> and the same outputs with :
> /Users/yt/bin/path_test.rb
>
> why do i have the same outputs in this case ?

Because the shell will also expand full names.  How does your PATH look 
like?  I assume you set something like PATH="${PATH}:${HOME}/bin" - in 
that case you'll have the absolute path to ~/bin in your PATH and 
consequently the script is invoked with absolute path.

> in fact i'm looking that because i do have Ruby class extension in a
> subfolder of "HOME/bin", namely :
> HOME/bin/ruby_ext
> where i put my extension for classes of which i could require :
> require "#{File.dirname($0)}/ruby_ext/ansi_color"
>
> what's the best way to require in that case, does i need an "absolute
> path (starting from / ) or not ?

IMHO the best way is to define a local location of library files and set 
RUBYLIB to that directory (I use "$HOME/lib/ruby" for that because I 
prefer to have lib code separate from programs, but in your case you 
could also use "$HOME/bin").

If you want to do it on a per script basis you could do this at the 
beginning of your script (i.e. before any requires):

$:.unshift "/your/folder/here"

Kind regards

	robert


-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/