From:	mcastle AT cs DOT umr DOT edu
Subject:	Re: environment and system calls
To:	djgpp AT sun DOT soe DOT clarkson DOT edu
Date:	Fri, 1 Jan 93 15:39:18 CST

Amazingly enough mcastle said:
>From mcastle Fri Jan  1 15:15:40 1993
Subject: Re: environment and system calls
To: ericb AT lsid DOT hp DOT com (Eric Backus)
Date: Fri, 1 Jan 93 15:15:40 CST
In-Reply-To: <9301012035 DOT AA15361 AT labejb DOT lsid DOT hp DOT com>; from "Eric Backus" at Jan 1, 93 12:35 pm
X-Mailer: ELM [version 2.3 PL11]

Amazingly enough Eric Backus said:
> In-Reply-To: <9212311355 DOT AA03458 AT express DOT ctron>; from "DJ Delorie" at Dec 31, 92 8:55 am
> Mailer: Elm [revision: 66.25]
> 
> > >I want to communicate with a subprocess that I spawn using the system 
> > >command.  I tried to do this by setting some environment variables
> > >using setenv().
> > 
> > The child runs off go32's environment, unfortunately.
> 
> It seems like we could make a new "turbo-assist" entry for setenv(),
> to set go32's environment and thus the child's environment.  Would
> this leave the parent's environment modifies when go32 exits?  If so,
> we'd have to work around that somehow.
> --
> 				Eric Backus
> 				ericb AT lsid DOT hp DOT com
> 				(206) 335-2495

I don't think this would affect the parent environment if you just use
the standard turbo-c libs (you CAN change the parent environment vars
under dos, but it involves mucking about with the PSP and stuff, and is
generally frowned upon :-).  Actually, go32 environment needs only be
modified on the system() call, so it wouldn't even have to be a 
turbo-assist entry.

A couple of problems I see with this though:  possibly running out of 
environment space (I'm not sure what happens if you don't have enough
room) and yet more realmode code added to go32 (do we really want 
this functionality?).  

mrc


-- 
Mike Castle .-=NEXUS=-.  Life is like a clock:  You can work constantly
  mcastle AT cs DOT umr DOT edu     and be right all the time, or not work at all
S087891 AT UMRVMA DOT UMR DOT EDU   and be right at least twice a day.  -- mrc
    We are all of us living in the shadow of Manhattan.  -- Watchmen

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