Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pacbell!att-ih!ihnp4!twitch!homxb!dean
From: dean@homxb.UUCP (D.JONES)
Newsgroups: comp.unix.questions
Subject: Re: Determining system memory
Message-ID: <1574@homxb.UUCP>
Date: 1 Apr 88 18:35:55 GMT
References: <248@lxn.UUCP> <1271@PT.CS.CMU.EDU>
Organization: AT&T Bell Laboratories, Holmdel
Lines: 25
Summary: sbrk(), ulimit()

In article <1271@PT.CS.CMU.EDU>, edw@IUS1.CS.CMU.EDU (Eddie Wyatt) writes:
>  > I have been trying to find a nice, clean way to determine system
>  > memory under SYS V 2.2.  I have come up with two solutions to this
>  > problem.  However, there must be a cleaner/faster way :-).
>  > Any other solutions are welcome (especially those that are faster :-)
> If what you are really interested in is the memory currently available
> to a given process I suggest using sbrk.  sbrk memory
> in fix block sizes until sbrk fails.
> Eddie Wyatt 				e-mail: edw@ius1.cs.cmu.edu

	Now you know how much memory you have for the current process, but
do you have to sbrk() it back if you are going to use malloc() ???  A call
to ulimit() on SysV 2.2 with an arg of 3 will return the max brk value for
the current process.  What about something <simple> like:

long memavail()
{
	return(ulimit(3) - (long)sbrk(0))
}

	It looks like this will work on our SunOS 4.0 machines also. I'm
Just starting to get into this UNIX stuff,   don't flame me if this is a
bozo idea...

					Dean S Jones
					AT&T Gateways!homxb!dean