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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.lang.c
Subject: Re: fgets
Message-ID: <6579@utzoo.UUCP>
Date: Thu, 10-Apr-86 17:59:39 EST
Article-I.D.: utzoo.6579
Posted: Thu Apr 10 17:59:39 1986
Date-Received: Thu, 10-Apr-86 17:59:39 EST
References: <2476@brl-smoke.ARPA>, <2524@utcsri.UUCP>
Organization: U of Toronto Zoology
Lines: 18

> ...So why doesn't fgets stick
> a '\0' in the buffer when it sees EOF immediately? Isn't this a bug?
> What I did to fix it was to set line_buffer[0]=NUL *before* calling
> fgets, which is simple enough to do. Still.... grumble, grumble...

Probably the right answer to this is that you should be checking the
return value from fgets, rather than consulting feof separately.  The
semantics of the return value aren't well explained in the manual, but
the code is doing the right thing:  you get NULL back only if there was
*nothing* available on the input.  If there's a partial line at the end
of the file, you get that partial line and a non-NULL return, and then
*next* time you get a NULL.

It is widely agreed that the details of the semantics of fgets could
have been done better.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,decvax,pyramid}!utzoo!henry