Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!ginosko!uunet!fernwood!vixie!avsd!childers
From: childers@avsd.UUCP (Richard Childers)
Newsgroups: comp.lang.c
Subject: Re: Help...
Message-ID: <2142@avsd.UUCP>
Date: 11 Oct 89 17:28:06 GMT
References: <731@carroll1.UUCP>
Reply-To: childers@avsd.UUCP (Richard Childers)
Organization: Metaprogrammers International
Lines: 40

dnewton@carroll1.cc.edu (Dave 'Yes, I'm weird' Newton) writes:

>Why doesn't this work?
>
>#include <stdio.h>
>main ()
>{
>   char      h[];
>   scanf ("%s", h);
>   printf ("%s\n", h);
>}

I compiled it and ran it without problems, on a Sun 3/50 running SunOS 3.5.
It did complain about a segmenttation fault and dump core, though. Probably
related to the fact that nowhere is the size of h[] defined. I defined it
and the problem went away.

If you think about it from the compiler's point of view, it makes sense. It
allocates space as it is told to. If you don't allocate space, it might or
might not make an educated guess, hand you a predetermined buffer of a fixed
size, or hand you nothing but a pointer to a single byte, assuming you mean
to define h[] as h[1].

>  It seems innocent enuf, but just prints garbage.  I'm missing something
>obvious, but I'll be darned if I know what it is.

Hope this is of assistance ...

>David L. Newton       |      dnewton@carroll1.UUCP     | Quote courtesy of
>(414) 524-7343 (work) |     dnewton@carroll1.cc.edu    | Marie Niechwiadowicz,
>(414) 524-6809 (home) | 100 NE Ave, Waukesha, WI 53186 | Boston College.

 -- richard


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