Newsgroups: comp.parallel.mpi
From: gdburns@osc.edu (Greg Burns)
Subject: Re: LAM I/O with a forked process using mpirun
Organization: Ohio Supercomputer Center
Date: 13 Sep 1996 19:53:06 -0400
Message-ID: <51cs52$t6s@tbag.osc.edu>

In article <3239C6EC.AEE@isl.hrl.hac.com> Justin Donnelly <justind@isl.hrl.hac.com> writes:
>I have a LAM application which forks a new process on each node.  This 
>child process is then responsible for user interaction.  If I start my
>application on each node manually, this is no problem.  However, using
>mpirun, stdout is displayed correctly on the screen, but stdin of the
>forked process is not connected to the keyboard.  This problem occurs
>with or without the -w option of mpirun.  Does anyoune know a
>workaround?

I hope you read my last posting on I/O in LAM 6.0.

Do I understand that you have processes on remote nodes that want
to do input and output to the terminal/window on the local node
(where you are sitting)?

One problem with UNIX stdin under LAM, which is only possible with
local node processes, is that UNIX stdin is inherited from the LAM
daemon, originally from lamboot, and not from mpirun.  So if you
switch windows/terminals between lamboot and mpirun, your local
processes will not be connected to the right place.  This anomaly
is corrected in LAM 6.1.

When you start your application manually, UNIX stdin is obviously
inherited directly from the shell, so all is well.

-=-
Greg Burns				gdburns@osc.edu
Ohio Supercomputer Center		http://www.osc.edu/lam.html

