Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!bbn!oberon!cit-vax!oxy!bagpiper
From: bagpiper@oxy.UUCP
Newsgroups: comp.lang.c
Subject: FILE * <-> System File Handles
Message-ID: <2.bagpiper@oxy.uucp>
Date: Thu, 1-Oct-87 19:00:00 EDT
Article-I.D.: oxy.2.bagpiper
Posted: Thu Oct  1 19:00:00 1987
Date-Received: Sat, 3-Oct-87 08:49:34 EDT
Organization: Occidental College
Lines: 49

In article <2853@husc6.UUCP>,ddl@husc6.UUCP (Dan Lanciani)
>In article <173@westmark.UUCP>, dave@westmark.UUCP (Dave Levenson) writes:
>| In article <1576@dicome.UUCP>, stryker@dicome.UUCP (don Stryker) writes:
>|
>| > I've run up against a disturbing feature of the Microsoft C compiler
>| > for the PC.  Microsoft limits an applicaton to 20 open files, 5 of
>| > which are taken up by the standard file handles.  I can open my files
>| > using DOS system calls to bypass the compiler, ...
>|
>| This limit is imposed by MS-DOS itself, not by the C compiler.
>
>        Unfortunately, the limit is also imposed by the C library
>which maintains its own table of open file descriptors.  This table
>contains information about the binary/text mode of the file and
>whether it is open (don't know why they really need the second).
>(This is for MSC 4.0.)
>
>
>                                        Dan Lanciani
>                                        ddl@harvard.*

ahhhh...I had a problem the other day the I think may have something to do
with this.  The following piece of code will clarify:

#include <stdio.h>
main()
{
 FILE *otherptr ;

 fprintf(stdprn,"This goes to the system printer!!") ;
 otherptr = strprn ;
 fprintf(otherptr,"And so does this...(on the same line even)\n") ;
 fclose(otherptr) ;
 fprintf(stdprn,"But this doesn't....???????\n") ;

}

BTW, this was using IBM C 1.0 (can anybody tell me roughly what MSC version
this is??).  fclose seems to have a FILE * linked in some manner with the
corresponding system file handle.  When you have two pointers sharing a handle
(as seems to happen in this case), fclose seems to close out both the system
handle as well as the FILE *.
Not the question is: Does this make sense?   I have been able to convince my
self both ways.  Anybody got a good argument!!

Michael Hunter         UUCP  : ....{seismo, rutgers, ames}!cit-vax!oxy!bagpiper
Box 241                ARPA  : oxy!bagpiper@csvax.caltech.edu
Occidental College     BITNET: oxy!bagpiper@hamlet.bitnet
Los Angeles, CA 90041  CSNET : oxy!bagpiper%csvax.caltech.edu@relay.cs.net