From: Eric Hodel <drbrain@...7.net>
Date: 2007-08-21T12:10:50+09:00
Subject: Dear Lazyweb: Gem Platforms

As you may or may not have heard, RubyGems will be merged into Ruby  
1.9 sometime in October.  Before this can happen RubyGems needs to  
automatically install dependencies based on platforms.  Fortunately  
I've got the automatic install part written.  Unfortunately I don't  
know if I've got figuring out the platforms right.  This is where you  
come in.

Dear Lazyweb,

Here's my proposal for how we recognize platforms.  From
Config::CONFIG, take the target_os and run it through a case
statement to figure out OS and OS version (if any).  Combine the
target_cpu, OS and OS version.  This value is your platform.

(There will be a rubygems-platforms.gem much like sources.gem that can
be updated as necessary.)

Using the tattle data (http://tattle.rubygarden.org), the following  
code recognizes 26 unique platforms:

def match(cpu, os)
   cpu = case cpu
         when /i\d86/ then 'x86'
         else cpu
         end

   os = case os
        when /cygwin/ then            [ 'cygwin',  nil ]
        when /darwin(\d+)?/ then      [ 'darwin',  $1  ]
        when /freebsd(\d+)/ then      [ 'freebsd', $1  ]
        when /^java([\d.]*)/ then     [ 'java',    $1  ]
        when /linux/ then             [ 'linux',   $1  ]
        when /mingw32/ then           [ 'mingw32', nil ]
        when /mswin32/ then           [ 'mswin32', nil ]
        when /openbsd(\d+.\d+)/ then  [ 'openbsd', $1  ]
        when /solaris(\d+\.\d+)/ then [ 'solaris', $1  ]
        else                          [ 'unknown', nil ]
        end

   [cpu, os].flatten.compact.join("-")
end

require 'rbconfig'

target_cpu = Config::CONFIG['target_cpu']
target_os = Config::CONFIG['target_os']

puts "Your target_cpu is:   #{target_cpu.inspect}"
puts "Your target_os is:    #{target_os.inspect}"
puts "Your platform is: #{match(target_cpu, target_os).inspect}"

Lazyweb, I have two major questions for you:

Did I get something wrong?  Am I using autoconf's target_os  
correctly?  Is Solaris 2.8 really incompatible with Solaris 2.9?   
What is a 64-bit Windows' target_os value?

Do I have all the platforms people run Ruby and RubyGems on?  If the  
answer to this one is no, do this: <kbd>gem install tattle; tattle</ 
kbd>.  (Yes, AIX users, I'm talking to you.)

--
Poor workers blame their tools. Good workers build better tools. The
best workers get their tools to do the work for them. -- Syndicate Wars