NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/os/msdos/desqview/4109

Internet Message Format | 1992-12-29 | 1.7 KB

Path: sparky!uunet!olivea!charnel!sifon!onsager.chem.mcgill.ca!ronis
From: [e-mail] (David Ronis)
Newsgroups: comp.os.msdos.desqview
Subject: fork() & pipe() in DVX
Message-ID: <[e-mail]>
Date: 29 Dec 92 18:31:40 GMT
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I'm currently porting ghostview to DV/X using djgpp and the X support released in
qdvx101.zip.  I get a clean compile, but end up with problems at link.  Specifically,
popen() and pclose() are missing.  Fortunately, all these are used for is to send stuff
to the printer, which I'm not too concerned about, and which I can easily fake.

When I try to run the program, however, things work well until it tries to spawn a subprocess.
Specifically, the program makes some pipes and then forks() [pipe() and fork() are just stubs
in djgpp 1.09], the child then sets stdin and stdout to the fd's of the opened pipes, and
exec's ghostscript to process the file.  If fork() worked, I would get into trouble since,
exec doesn't.

My question is this:  can I fake fork() using the routines in dvapi?  Clearly I can spawn a
subprocess, but how do I get the subprocess to inherit my file descriptors?  Does this happen
automatically?

Finally, at some point the parent program want's to kill the child.  It does this using kill()
followed by wait(); here, too all I have are stubs.  There doesn't seem to be anything in the
dvapi routines in qdvx101 that allows me to kill the child, although the documentation says
that NewProc returns the handle of the opened process, shouldn't I be able to kill the child?

Thanks in advance,

David Ronis