brew/Library/Homebrew/cmd/prune.rb

require 'keg'

module Homebrew extend self
  # $n and $d are used by the ObserverPathnameExtension to keep track of
  # certain filesystem actions.

  def prune
    $n = 0
    $d = 0
    dirs = []

    Keg::PRUNEABLE_DIRECTORIES.map{ |d| HOMEBREW_PREFIX/d }.each do |path|
      next unless path.directory?
      path.find do |path|
        path.extend ObserverPathnameExtension
        if path.symlink?
          unless path.resolved_path_exists?
            if ENV['HOMEBREW_KEEP_INFO'] and path.to_s =~ Keg::INFOFILE_RX
              path.uninstall_info
            end
            path.unlink
          end
        elsif path.directory?
          dirs << path
        end
      end
    end

    dirs.sort.reverse_each{ |d| d.rmdir_if_possible }

    if $n == 0 and $d == 0
      puts "Nothing pruned" if ARGV.verbose?
    else
      print "Pruned #{$n} symbolic links "
      print "and #{$d} directories " if $d > 0
      puts  "from #{HOMEBREW_PREFIX}"
    end
  end
end