Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: CALLOC and MALLOC
Message-ID: <7168@brl-smoke.ARPA>
Date: 22 Jan 88 21:17:14 GMT
References: <11415@brl-adm.ARPA>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <11415@brl-adm.ARPA> V4039%TEMPLEVM.BITNET@CUNYVM.CUNY.EDU (Stan Horwitz) writes:
>Why do the basic memory allocation functions CALLOC and MALLOC clear the newly
>allocated memory they yield?

malloc() doesn't.  calloc() stores 0 bytes in the allocated area, which may
not be equivalent to 0-valued objects if some of the storage is interpreted
as pointers or floating-point data.

>I am a novice C programmer and am trying to build dynamic arrays as I
>data is received by the program in question, yet each time I add a new
>element of memory onto my array, all the previous elements are cleared.

I don't know how you're trying to do this; realloc() is used to extend
the allocated memory, and it does NOT alter the previous contents,
although it may move them to new addresses.