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From: poser@csli.Stanford.EDU (Bill Poser)
Newsgroups: comp.unix.wizards
Subject: Re: Program Memoryj Usage from 'C'
Keywords: dynamic memory sbrk end
Message-ID: <11438@csli.Stanford.EDU>
Date: 14 Dec 89 08:14:17 GMT
References: <601@h.cs.wvu.wvnet.edu>
Sender: poser@csli.Stanford.EDU (Bill Poser)
Reply-To: poser@csli.stanford.edu (Bill Poser)
Followup-To: comp.unix.wizards
Organization: Center for the Study of Language and Information, Stanford U.
Lines: 15

The following occurs to me as a way of determining how much
memory has been allocated dynamically, though I am not
clear if the poster really wants to know about heap memory
or stack memory.

First, the sbrk system call, used to extend the processes' data region,
returns the old value of the endpoint. So doing sbrk(0), asking for
an extension of 0 bytes, should give you the current endpoint.

Second, the external variables end, etext, and edata (see section 3 of
the manual) contain the address one beyond the end of the processes
uninitialized data, program text, and initialized data. So the
amount of memory allocated on the  should be:

	sbrk(0) - end + 1