From: "A. Sinan Unur" <asu1 AT cornell DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: fread/fwite return value (CORRECTION)
Date: Wed, 16 Jul 1997 17:58:28 -0400
Organization: Cornell University http://www.cornell.edu
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A. Sinan Unur wrote:

> that is at best worthless advice. the documentation in this case is
> plain wrong. it is a small mistake, but fread is supposed to return 0 
> in case of error.

oh, boy, do i love correcting myself. i checked the excerpt from the
ansi standard in Plauger's "The Standard C Library". it says:

7.9.8.1 The fread function

Synopsis
  #include <stdio.h>
  size_t fread(void *ptr, size_t size, size_t nmemb, FILE* stream);

...

Returns
  The fread function returns the number of elements successfully read,
which may be less than nmemb if a read error or EOF is encountered. If
size or nmemb is zero, fread returns zero and the contents of the array
and the state of the stream remain unchanged.

Later on, on p.271, he comments: "if the second argument is greater than
one, you cannote determine whether the function also read up to size - 1
additional characters beyond what it reports. As a rule you are better
off calling the function as

fread(buf, 1, size*n, stream)

instead of

fread(buf, size, n, stream)."

it follows that you can only count on fread returning zero in case of
failure if you use the latter form.
-- 
   Sinan
 
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