gistfile1.rb

module Util
  def Util.not_implemented
    raise "not implemented yet"
  end

  def Util.kill_process_if_exists pid
    running = true
    begin
      Process.kill(0, pid)
      #if we get here the process is alive


    rescue Errno::EPERM # changed uid
      # puts "#{pid} has escaped my control!";
      running = false
    rescue Errno::ESRCH
      #puts "#{pid} is deceased."; # or zombied
      running = false
    rescue
      raise "Odd; I couldn't check the status of #{pid} : #{$!}"
    end
    if running
      begin
        Process.detach pid
      rescue
        puts "could not detach from process"
      end
      begin
        Process.kill 'SIGKILL', pid
      rescue => e
        raise "count not kill process #{pid} #{e}"
      end
    end

  end

  def Util.shell_with_timeout(cmd, seconds = 3600)
    #the default timeout is an hour. That's probably way too long

    Timeout::timeout(seconds) {

      @pid, @stdin, @stdout, @stderr = Open4.popen4(cmd)

      ignored, @status = Process::waitpid2 @pid

      if @status.exitstatus != 0
        raise "Exit Status not zero"
      end

    }

    @stdout ? @stdout.read.strip : ''
  rescue Timeout::Error

    raise "Process Timed out"
  rescue => e

    msg =  @stderr ? @stderr.read.strip : ''
    msg +=   e.to_s


    raise "Error during execution of command #{cmd}\n #{msg}"
  ensure
    Util::kill_process_if_exists @pid
  end
end