Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uwm.edu!bionet!ames!sgi!shinobu!odin!elysium!archer
From: archer@elysium.sgi.com (Archer Sully)
Newsgroups: comp.lang.c
Subject: Re: Child processes redefined
Message-ID: <10185@odin.corp.sgi.com>
Date: 10 Jul 90 21:47:49 GMT
References: <12473@june.cs.washington.edu> <1990Jul6.145122.14785@usenet@kadsma>
Sender: news@odin.corp.sgi.com
Distribution: na
Lines: 25

In article <1990Jul6.145122.14785@usenet@kadsma> pajerek@usenet@kadsma (Don Pajerek) writes:

>In article <12473@june.cs.washington.edu> ojpotter@fred.cs.washington.edu () writes:
>> I want to use these external
>>executables as runtime functions.  I want to pass them parameters and get a
>>calculated return value back.
>>

>Am I missing something, or won't fork/exec do the job?

It may.  Then again, it may not.  If the dynamic function needs to access
data and text from the main program, then using a fork/exec scheme will
be either insufficient or inefficient, because the data would have to 
be passed through some arcane means (encoding in strings for parameters,
shared memory, etc...).   Return values suffer similar problems.  If all
that is needed is an int return, then it shouldn't be too tough, but if
floating point or a structure of some sort is required, it gets more 
difficult.

The C language does not define dynamic loading.  That is a feature of the
operating system, and many do not have it.  

Archer Sully 	      |  Ask not what you can do for you country,
(archer@esd.sgi.com)  |  But what your country's been doing to you.
                      |                    -- The Avengers