# File lib/rubygems/commands/which_command.rb, line 8
 8:   def initialize
 9:     super 'which', 'Find the location of a library file you can require',
10:           :search_gems_first => false, :show_all => false
11: 
12:     add_option '-a', '--[no-]all', 'show all matching files' do |show_all, options|
13:       options[:show_all] = show_all
14:     end
15: 
16:     add_option '-g', '--[no-]gems-first',
17:                'search gems before non-gems' do |gems_first, options|
18:       options[:search_gems_first] = gems_first
19:     end
20:   end

    # File lib/rubygems/commands/which_command.rb, line 30
30:   def execute
31:     searcher = Gem::GemPathSearcher.new
32: 
33:     found = false
34: 
35:     options[:args].each do |arg|
36:       dirs = $LOAD_PATH
37:       spec = searcher.find arg
38: 
39:       if spec then
40:         if options[:search_gems_first] then
41:           dirs = gem_paths(spec) + $LOAD_PATH
42:         else
43:           dirs = $LOAD_PATH + gem_paths(spec)
44:         end
45:       end
46: 
47:       paths = find_paths arg, dirs
48: 
49:       if paths.empty? then
50:         alert_error "Can't find ruby library file or shared library #{arg}"
51:       else
52:         say paths
53:         found = true
54:       end
55:     end
56: 
57:     terminate_interaction 1 unless found
58:   end

    # File lib/rubygems/commands/which_command.rb, line 60
60:   def find_paths(package_name, dirs)
61:     result = []
62: 
63:     dirs.each do |dir|
64:       EXT.each do |ext|
65:         full_path = File.join dir, "#{package_name}#{ext}"
66:         if File.exist? full_path then
67:           result << full_path
68:           return result unless options[:show_all]
69:         end
70:       end
71:     end
72: 
73:     result
74:   end

    # File lib/rubygems/commands/which_command.rb, line 76
76:   def gem_paths(spec)
77:     spec.require_paths.collect { |d| File.join spec.full_gem_path, d }
78:   end