class Byebug::RestartCommand

def execute
  if not defined? Byebug::PROG_SCRIPT
    errmsg "Don't know name of debugged program\n"
    return
  end
  if not File.exist?(File.expand_path(Byebug::PROG_SCRIPT))
    errmsg "Ruby program #{Byebug::PROG_SCRIPT} doesn't exist\n"
    return
  end
  if not defined? Byebug::RDEBUG_SCRIPT
    print "Byebug was not called from the outset...\n"
    if not File.executable?(Byebug::PROG_SCRIPT)
      print "Ruby program #{Byebug::PROG_SCRIPT} not executable... " \
            "We'll add a call to Ruby.\n"
      ruby = begin defined?(Gem) ? Gem.ruby : "ruby" rescue "ruby" end
      byebug_script = "#{ruby} -I#{$:.join(' -I')} #{Byebug::PROG_SCRIPT}"
    else
      byebug_script = Byebug::PROG_SCRIPT
    end
  else
    byebug_script = Byebug::RDEBUG_SCRIPT
  end
  begin
    Dir.chdir(Byebug::INITIAL_DIR)
  rescue
    print "Failed to change initial directory #{Byebug::INITIAL_DIR}"
  end
  if @match[1]
    argv = [Byebug::PROG_SCRIPT] + @match[1].split(/[ \t]+/)
  else
    if not defined? Command.settings[:argv]
      errmsg "Arguments have not been set. Use 'set args' to set them.\n"
      return
    else
      argv = Command.settings[:argv]
    end
  end
  cmd = "#{byebug_script} #{argv.compact.join(' ')}"
  # An execv would be preferable to the "exec" below.
  print "Re exec'ing:\n\t#{cmd}\n"
  exec cmd
rescue Errno::EOPNOTSUPP
  print "Restart command is not available at this time.\n"
end

def help(cmd)
  %{
    restart|R [args]
    Restart the program. This is a re-exec - all byebug state
    is lost. If command arguments are passed those are used.
  }
end

def help_command
  'restart'
end

def regexp
  / ^\s*
  (?:restart|R)
  (?:\s+ (\S?.*\S))? \s*
  $
  /ix
end