Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!rpi!tale
From: tale@pawl.rpi.edu (David C Lawrence)
Newsgroups: comp.emacs
Subject: Re: using a subprocess for printing
Message-ID: <1989Oct11.043450.2633@rpi.edu>
Date: 11 Oct 89 04:34:50 GMT
References: <337@mlfarm.UUCP>
Organization: Rensselaer Polytechnic Institute, Troy NY
Lines: 41

[Fourth UUCP bounce today.  Blargh.]

In <337@mlfarm.UUCP> ron@mlfarm.UUCP (Ronald Florence) writes:
Ronald> I would welcome suggestions on how to start a subprocess to run troff
Ronald> on the contents of a GNU Emacs buffer.  Currently, I use the following
Ronald> code

Ronald> [Code deleted.]

The problem here is that you are using call-process-region, which is
designed to wait until the process returns.  GNU Emacs has much more
rich process handling ability as long as "subprocesses" was #defined
and accurate for your system when Emacs was compiled.  From what you
said later about your system, this is probably the case.

Based on the code you provided, the same results, but asynchronous
execution of the script, could be accomplished using the following
skeleton algorithm:

(defun your-entry-command ...
   (interactive ...)
   (start-process ...) ;; pick up process-object here
   (set-process-sentinel process-object 'your-proc-sentinel)
   (process-send-region process-object (point-min) (point-max)))

(defun your-proc-sentinel ...
   (if the process has exited ...
       ( ... do your clean-up stuff ...)))

For the start-process you can get-buffer-create and erase-buffer an
object based on " *emacstroff output*" or such.  The leading space
makes it a hidden buffer because the user shouldn't bother with the
fact that it exists.  The clean-up part is where you build your
minibuffer message and kill the temporary buffer.

For more information do an apropos (not command-apropos) on "process"
and see what it turns up.

Dave
-- 
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