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From: M C Wong <mcw@hpato.aus.hp.com>
Subject: conditionally optional parameter in C function declartion
To: questions@freebsd.org
Date: Tue, 3 Sep 96 10:38:59 EST
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Hi,
    Maybe I am being paranoia, but different systems have
different declaration for open(2):

eg on HPUX:
#include <fcntl.h>

int open( const char *path, int oflag, ...  /* mode_t mode */);

eg on FreeBSD:
int open(const char *path, int flags, mode_t mode)

Which is more POSIX than another ?

Also, the use of mode depends very much of the value of oflag
ie only when O_CREAT is part of the value of flags.

My question is, if someone is to specify many of such
functions with conditionally optional parameter, is there
a better way of specifying the declaration accurately to
reflect the conditional nature, and not doing in it the
man page or comments ?