From: James Edward Gray II <james@...>
Date: 2007-04-19T22:34:47+09:00
Subject: Re: Executing program from ruby

On Apr 19, 2007, at 8:21 AM, Marcin Raczkowski wrote:

> any expirience with open4? help? pointers?

TextMate uses a hand-rolled popen3(), which is really just an open4()  
clone.  Allan Odgaard, the creator of TextMate, wrote the code, but  
it's straightforward enough that I thought it might help you to see it:

def my_popen3(*cmd) # returns [stdin, stdout, strerr, pid]
   pw = IO::pipe   # pipe[0] for read, pipe[1] for write
   pr = IO::pipe
   pe = IO::pipe

   pid = fork{
     pw[1].close
     STDIN.reopen(pw[0])
     pw[0].close

     pr[0].close
     STDOUT.reopen(pr[1])
     pr[1].close

     pe[0].close
     STDERR.reopen(pe[1])
     pe[1].close

     exec(*cmd)
   }

   pw[0].close
   pr[1].close
   pe[1].close

   pw[1].sync = true

   [pw[1], pr[0], pe[0], pid]
end

Hope that helps.

James Edward Gray II