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From: olson@anchor.esd.sgi.com (Dave Olson)
Newsgroups: comp.unix.bsd
Subject: Re: Beware of fileno()
Keywords: sunos, ultrix, stdio, fileno, lossage, irix
Message-ID: <nrg0vuk@zuni.esd.sgi.com>
Date: 28 Jul 92 03:06:39 GMT
References: <14njaeINNvk@agate.berkeley.edu> <1992Jul24.062320.2170@kithrup.COM> <1992Jul24.141048.10911@aosg.gsf.dec.com> <1217@ki.com>
Sender: news@zuni.esd.sgi.com (Net News)
Organization: Silicon Graphics, Inc. Mountain View, CA
Lines: 32
In <1217@ki.com> dwatts@ki.com (Dan Watts) writes:
| In article <1992Jul24.141048.10911@aosg.gsf.dec.com> reeves@decvax.dec.com writes:
| ||> >Sean Eric Fagan |> Andreas Stolcke
| ||> >... fileno() returns a char field in the FILE structure...one has to use
| ||> > (unsigned char)fileno(stream)
| ||> Current BSD sources have the _file element as a short.
| |
| |The same change went into ULTRIX over a year ago; I believe it's been released
| |for nearly a year (it was definitely in V4.2, which isn't even the current
| |release any more).
| |--
| |Jon Reeves Digital Equipment Corporation, Alpha Open Systems Group
| | 5 Wentworth Drive, MS GSF1-1K13, Hudson NH 03051-4929 USA
| |+1 603 884 5859 reeves@decvax.dec.com FAX: +1 603 884 1685
|
| SGI Irix 4.0.1 still has it as "char _file;". I wonder if they've
| fixed it yet? Luckily, the default behaviour for the SGI C compiler
| is to treat all chars as unsigned.
We only go up to 100 files per process by default; 200 can be
configured in 4.0.5 though. In any case, characters are unsigned by
default. If you use -signed when compiling, and you configure the
system for more files per process, then yes, this could be a problem,
EXCEPT, that stdio will deal with at most 100 files, even if the system
limit is configured higher, so it is pretty unlikely, although not
impossible, for this to be a problem.
--
Let no one tell me that silence gives consent, | Dave Olson
because whoever is silent dissents. | Silicon Graphics, Inc.
Maria Isabel Barreno | olson@sgi.com