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From: misha@daisy.UUCP (Mike Umansky)
Newsgroups: net.unix,net.unix-wizards,net.arch,net.lang.c
Subject: get size of malloc'd object
Message-ID: <165@daisy.UUCP>
Date: Thu, 12-Jun-86 18:22:27 EDT
Article-I.D.: daisy.165
Posted: Thu Jun 12 18:22:27 1986
Date-Received: Sun, 15-Jun-86 04:10:29 EDT
Distribution: net
Organization: Daisy Systems Corp., Mountain View, Ca
Lines: 30
Xref: linus net.unix:7437 net.unix-wizards:15318 net.arch:3122 net.lang.c:8615


	I have a need in my application to find the size of a
	previously malloc'd object (maybe an array or structure).
	For example, one routine may allocate some array or just
	one big chunk of memory and pass a pointer to the chunk to
	another routine.  This other routine now needs to know the
	size of the area pointed to by this pointer.  Also, this
	other routine has no idea about the structure of this area
	and doesn't even care.  Now, the question, how can this
	other routine get the size of the area pointed to by passed
	pointer.  Would (sizeof(*ptr)) work or will it just give
	me the size of the pointer type?  Another possibility would
	be to write a routine which would scan malloc's allocation
	array and try to match the pointers; then the size is
	easily obtained.  Any help and comments on this would be
	greately appreciated.  Either post your answers or mail them
	directly please.  Thanks for consideration.
-- 
--
		NAME:	Michael Umansky (misha)
		E-MAIL: ucbvax!hplabs!nsc!daisy!misha
		WORK:
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