# Author::    Nicolas Pouillard  <ertai@lrde.epita.fr>.
# Copyright:: Copyright (c) 2004, 2005 Uttk team. All rights reserved.
# License::   LGPL
# $Id: /w/fey/uttk/trunk/lib/uttk/strategies/CmdBase.rb 21844 2006-02-17T17:26:59.771162Z pouillar  $


module Uttk

  module Strategies

    class CmdBase < IOBased
      include Abstract

      #
      # Constructor
      #

      def initialize ( *a, &b )
        super
        @my_exit, @pid, @my_status = nil, nil, nil
      end


      #
      # Methods
      #

      def run_impl
        begin
          cmd = mk_command
          cmd.gsub!("\n", ' ')

          @log[:running] = cmd

          @pid = Kernel.fork do
            unless @input.nil? or @input_in_args
              STDIN.reopen(@input.my.open('r'))
            end
            STDOUT.reopen(@output.my.open('w')) unless @output.nil?
            STDERR.reopen(@error.my.open('w')) unless @error.nil?
            Dir.chdir(@dir.to_s) if @dir
            begin
              son_hook
              exec(cmd)
            rescue Exception => ex
              @log.exception_raised_during_exec = ex
              exit! 127
            end
          end
          father_hook
          waitpid
          fail('exception raised during exec') if @my_exit == 127
        end
      end
      protected :run_impl


      def son_hook
      end
      protected :son_hook


      def father_hook
      end
      protected :father_hook


      def abort_hook
        unless @pid.nil?
          begin
            Process.kill('-KILL', -@pid)
            waitpid
          rescue Errno::ESRCH
            @log.already_killed = @pid
          end
        end
        @my_exit = 134 # Common status returned by sh on a SIGABRT
        super
      end
      protected :abort_hook


      def waitpid
        return if @pid.nil? or not @my_status.nil?
        Process.waitpid(@pid)
        @my_status = $?
        @my_exit = @my_status.exitstatus
      end
      protected :waitpid


      def mk_command
        cmd = @command.to_s.dup
        cmd += ' %a' if cmd !~ /%a/ and @args
        cmd.gsub!(/%a/, @args.to_s) if @args
        if cmd =~ /%i/ and @input and @input.my
          cmd.gsub!(/%i/, @input.my.to_s)
          @input_in_args = true
        else
          @input_in_args = false
        end
        cmd
      end
      protected :mk_command


      def epilogue
        waitpid
        super
      end


      #
      # Attributes
      #

      attr_reader :my_exit, :my_status, :pid

      attribute :command, 'the command to execute', :mandatory,
                          [String, Pathname, Array]
      attribute :dir,     'the directory where to launch the command',
                          [String, Pathname]
      attribute :args,    'the arguments for the command',
                          [Array, String, Numeric]

    end # class CmdBase

  end # module Strategies

end # module Uttk