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Article #6803Fgets and malloc_verify()
From: Richard Doherty
Date: Wed, 13 Feb 1991 22:03
Date: Wed, 13 Feb 1991 22:03
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1412 bytes
It appears that malloc_debug() believes that fgets() makes a call to malloc() with size of 0. This in itself is alright, except that malloc_debug() (and therfore malloc_verify()) abort as soon as they discover this, making them useless for further debugging. Details: OS4.0.1 Sun4 (Sparc) When NOT linked with /usr/lib/debug/malloc.o, fgets() does not display this behavior -- determined by writing another malloc routine local to the routine, and checking for size of 0. Malloc_verify() called anytime after the call to fgets() reports that the heap is corrupt (having a block size of 0 for one entry) and aborts. This may indeed simply be a much more obscure memory problem in my program itself. It makes malloc_verify() useless (although, admittedly, I have never found it all that useful in the first place). --Rich
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!cunews!bnrgate!brtph3!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request From: emperor!sugar!richd@uunet.uu.net (Richard Doherty) Newsgroups: comp.sys.sun Subject: Fgets and malloc_verify() Keywords: SunOS Message-ID: <1610@brchh104.bnr.ca> Date: 13 Feb 91 22:03:00 GMT Sender: news@brchh104.bnr.ca Organization: Sun-Spots Lines: 23 Approved: Sun-Spots@rice.edu X-Original-Date: 7 Feb 91 02:07:20 GMT X-Sun-Spots-Digest: Volume 10, Issue 31, message 15 X-Note: Submissions: sun-spots@rice.edu, Admin: sun-spots-request@rice.edu