From: Paul Brannan <pbrannan@...>
Date: 2002-04-12T08:01:28+09:00
Subject: Re: Process controlls

On Fri, Apr 12, 2002 at 06:16:42AM +0900, JohnW wrote:
> I'm a QA guy that wants to automate testing.  The test involves
> launching an executable...which, in turn, launches other executables. 
> I want to be able to have the script maintain focus and wait for the
> test to finish (I drop a done file) then send like a ^C to the process
> it started.

I am a fellow test writer.  I've needed to do something similar in my
tests.

I use CORBA to communicate between the processes (I get Ruby to talk
CORBA via a C++ extension).  My code looks something like:
  pid = fork do
    exec "/bin/foo"
  end

  begin
    sleep(5)    # wait for the child to start
    $obj->foo() # make a CORBA call and wait for it to return
  ensure
    Process.kill("SIGTERM", pid)
  end

If you want to simulate a Ctrl-C, then you might try using SIGINT
instead of SIGTERM.

In your case, instead of waiting for a CORBA call to return, you want to
wait for a file to appear:

  catch :done do
    loop do
      begin
        File.open("filename") { throw :done }
      rescue Exception
      end
      sleep 1
    end
  end

(maybe not the simplest way to do this, but I think it will work).

Hope this helps,

Paul