From: Paul Lutus <nospam@...>
Date: 2006-11-25T17:20:13+09:00
Subject: Re: [Mac OS X] having three ruby versions installed

Une b辿vue wrote:

> on my box running Mac OS X (Tiger the latest) i do have three ruby
> versions :
> 
> - /usr/bin/ruby  # Apple's default installed version :
> # => 1.8.2
> - /opt/local/bin/ruby # the MacPort version :
> # => 1.8.5
> - /Users/yvon/bin/jruby/jruby # svn installed
> # => 1.8.5 (0) [java]
> 
> both MacPort and SVN versions cohabit nicely because using zsh (shell)
> aliases all commands of jruby have a "j" prefix and using a ~/.jgemrc
> i'm able to switch env vars between them.
> 
> then, the prob, reason for posting here, come with the default installed
> version.
> 
> here, when doing a :
> $ /usr/bin/ruby wav2xml.rb bidule.wav  # i get :
> /usr/bin/ruby: No such file to load -- ubygems (LoadError)
> 
> i think this is due to some env vars i setup :
> export RUBYOPT=rubygems
> export GEM_HOME=/opt/local/lib/gems/1.8
> export RUBYLIB=/opt/local/lib/ruby/:/opt/local/lib/ruby/site_ruby/1.8
> 
> because i've to design some scripts usable with apple's default version,
> i'd like to find a workaround for that error message without installing
> anything within Apple's ruby...
> 
> do you have a trick for that ?

Figure out what your search path is and symlink the desired Ruby version
into the earliest (first searched) executable directory.

Example. Let's say you have directory /usr/local/bin, and it is the first
searched executable directory, and you want to execute /opt/local/bin/ruby
instead of the Ruby version located at /usr/bin/ruby.

Move to directory /usr/local/bin, type this as root:

# ln -s /opt/local/bin/ruby ruby

Then test whether this worked. As a normal user:

$ ruby -version

But having multiple Ruby versions installed is a bad idea, because the
different versions use libraries, some of them shared, that may cause
conflicts.

-- 
Paul Lutus
http://www.arachnoid.com