link_gnu_coreutils.rb

#!/usr/bin/env ruby
#coding:utf-8
require 'pp'
require 'optparse'

opt = OptionParser.new
link=nil
begin 

 opt.on("-e", "--link","brew の gnuコマンドを/usr/local/bin にリンクします"){ link=true; }
 opt.on("-d", "--unlink","brew の gnuコマンドを/usr/local/bin から削除します"){ link=false }

 opt.parse!(ARGV)

 if link.nil?
  raise OptionParser::InvalidOption
 end

rescue OptionParser::InvalidOption
 ARGV << "-h"
 retry
end

cmds = Dir.glob("/usr/local/opt/coreutils/libexec/gnubin/*").map{|e| e}

cmds.each{|e|


 case link 
  when true

   puts "link #{e} --> /usr/local/bin/#{File.basename e}\n" if link == true
   File.unlink "/usr/local/bin/#{File.basename e}" if File.exist?("/usr/local/bin/#{File.basename e}")
   File.symlink e, "/usr/local/bin/#{File.basename e}" 
  when false
   puts "unlink /usr/local/bin/#{File.basename e}\n" if link == false
   File.unlink "/usr/local/bin/#{File.basename e}" if link == false
 end


}