Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!ucbcad!ucbvax!cbosgd!clyde!watmath!rbutterworth
From: rbutterworth@watmath.waterloo.edu (Ray Butterworth)
Newsgroups: comp.lang.c
Subject: Re: Another thing broken in ANSI C
Message-ID: <16049@watmath.waterloo.edu>
Date: 29 Dec 87 14:16:54 GMT
References: <3726@hoptoad.uucp> <7109@apple.UUCP>
Organization: U of Waterloo, Ontario
Lines: 20

In article <7109@apple.UUCP>, kanner@apple.UUCP (Herbert Kanner) writes:
> Not quite.  Take printf for example.  True, it has to be defined with
> the (format, ...) notation, but it is a library function and not your
> problem.  Declarations of the form int printf(); are completely
> acceptable; see Section 3.5.3.3, which states: "... an empty list in a
> function declaratorthat is not part of a function definition specifies
> that no information about the number or types of the parameters is
> supplied."

Not quite.  Declarations of the form "int printf();" are not completely
acceptable.  What is acceptable is
    #undef printf
    int printf();

I already ran into this problem trying to compile something on an
ANSI (or as close as one can get to a moving target) C compiler.
The program  contained the declaration "extern int istty();".
This didn't work too well when the <stdio.h> file had a #define
for isatty(s).  It is perfectly acceptable for the header file to
have a #define for almost any library function.  If you want them
to be real functions you have to #undef them before you use them.