#!/usr/bin/ruby

require 'rubygems/package'

module RubyGemsProv

  module Helpers

    # If there is some prelease version files, such as rc1 (i.e. non-numeric

    # field), prepend this field by tilde instead of dot.

    def self.normalize_prerelease(version)

      if version.prerelease?

        prerelease = version.version.sub /^#{version.release}\./, ''

        "#{version.release}~#{prerelease}"

      else

        version.release

      end

    end

  end

  # Reports all functionality gem provides.

  def self.provides

    while filename = gets

      filename.strip!

      begin

        specification = Gem::Specification.load filename

        puts "rubygem(#{specification.name}) = #{Helpers::normalize_prerelease(specification.version)}"

      rescue => e

        # Ignore all errors.

      end

    end

  end

end

if __FILE__ == $0

  RubyGemsProv::provides

end