NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part2/11859

Internet Message Format | 1996-08-05 | 1.6 KB

Path: keats.ugrad.cs.ubc.ca!not-for-mail
From: [e-mail] (Kazimir Kylheku)
Newsgroups: comp.lang.c
Subject: Re: Is there a problem using memset on a malloc'd memory in HP-C
Date: 26 Mar 1996 16:06:29 -0800
Organization: Computer Science, University of B.C., Vancouver, B.C., Canada
Message-ID: <[e-mail]>
References: <31a7cc$10b20.32c@NEWS>
NNTP-Posting-Host: keats.ugrad.cs.ubc.ca

In article <31a7cc$10b20.32c@NEWS>,
Jonathan Julian <[e-mail]> wrote:
 >I have searched your FAQ and found no reference to this problem.
 >
 >I am having trouble doing a malloc on memory that I allocated via
 >malloc.  I malloc'd the memory, memset it  and immediately look at it
 >and it is garbage.  I have changed my mallocs to callocs, but later in
 >my code I realloc.  Since realloc does not initialize and I
 >distrusting of memset I have written a loop to initialize my memory.

Unfortunately, without seeing the source code demonstrating your use of
malloc() and memset(), there is little that can be done in the way of help.

 >The structure that I am trying to initialize is an array of pointers
 >to pointers that I would initially like to be NULL.  I am on HP
 >a.09.07  using HP-C

Unfortunately, if you expect a block of zero bits to represent null pointers,
you are making a machine-specific assumption. The null pointer is not required
by the C standard to have a zero-bit representation, to reflect the reality
that on some machines the best represetnation for a null pointer is something
other than a word of zero bits.

If you want to be strictly conforming, you should intitialize each pointer by
explicit assignment.
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