Article View: comp.os.msdos.programmer
Article #5565Re: How to change Number of Open Files
From: Raymond Chen
Date: Tue, 02 Apr 1991 00:04
Date: Tue, 02 Apr 1991 00:04
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In article <1991Apr1.023910.22196@hellgate.utah.edu>, bwilliam%peruvian (Bruce R. Williams) writes:
>It isn't a matter of how many buffers you have, it's a limit set inside DOS.
Actually, it's a limit that Borland stupidly hard-coded into their
library support routines. If you study the library source code,
you'll see a line that says
#define NFILES 20
and then external arrays _openfd and _iobuf declared to be NFILES
elements long. (I may have the array names wrong; I'm working
from memory.) The number twenty is HARD-CODED into all of the
I/O support routines (fopen, read, seek, etc.), so the only way
to get around the limit is either
[1] Buy the TC source code, change the #define and recompile.
[2] Reverse-engineer the library object code and change the 20 to
a larger number in all of the functions where it appears,
as well as deleting the OBJs that declare _iobuf and _openfd
and adding replacements that declare them with a larger size.
[3] Avoid the supplied functions and talk to DOS directly.
[4] Switch to a different compiler. (MSC comes with instructions
in one of its README files on how to increase the number
of open files.)
I can probably help anyone who wants to try method [2].
Technical Details
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!ucbvax!agate!usenet From: raymond@math.berkeley.edu (Raymond Chen) Newsgroups: comp.os.msdos.programmer Subject: Re: How to change Number of Open Files Message-ID: <1991Apr2.000459.23232@agate.berkeley.edu> Date: 2 Apr 91 00:04:59 GMT References: <1991Mar31.011139.8147@news.arc.nasa.gov> <1991Mar31.213543.28347@news.iastate.edu> <1991Apr1.023910.22196@hellgate.utah.edu> Sender: usenet@agate.berkeley.edu (USENET Administrator) Reply-To: raymond@math.berkeley.edu (Raymond Chen) Organization: U.C. Berkeley Lines: 26 In-Reply-To: bwilliam%peruvian.utah.edu@cs.utah.edu (Bruce R. Williams)