From owner-freebsd-hackers  Sun Jun  2 16:32:35 1996
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id QAA19098
          for hackers-outgoing; Sun, 2 Jun 1996 16:32:35 -0700 (PDT)
Received: from harbor.silcom.com (harbor.silcom.com [199.201.128.1])
          by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id QAA19092;
          Sun, 2 Jun 1996 16:32:32 -0700 (PDT)
Received: from beach.silcom.com (root@beach.silcom.com [199.201.128.19]) by harbor.silcom.com (8.6.12/8.6.9) with ESMTP id QAA05123; Sun, 2 Jun 1996 16:33:48 -0700
Received: from zoof.cts.com by beach.silcom.com (8.6.12/SMI-4.1)
	id QAA21127; Sun, 2 Jun 1996 16:31:42 -0700
Received: from zoof.cts.com ([127.0.0.1]) by zoof.cts.com
          (post.office MTA v2.0 pre-alpha ID# 0-1001) with SMTP id AAA131;
          Sun, 2 Jun 1996 16:29:31 -0700
From: pjf@cts.com (Paul Falstad)
Message-Id: <9606021629.ZM129@zoof>
Date: Sun, 2 Jun 1996 16:29:30 -0700
In-Reply-To: Bruce Evans <bde@zeta.org.au>
        "Re: bugs" (Jun  3,  6:52am)
In-Reply-To: Alex Nash <alex@zen.nash.org>
        "Re: bugs" (Jun  2,  5:25pm)
References: <199606022052.GAA06199@godzilla.zeta.org.au> 
	<199606022225.RAA23224@zen.nash.org>
X-Face: ECcdcE"#6HK`bju2deH)DfABe@eZcG/9(w';j/n-Hat1joHF.d|1HwhhOBX+3{zjfAH$@C@
 og1k*RjD=WSww/5"ZDk_FIabxydm\%u*)TDP@Q;Ag5'p@lnm*0LV(zcvPE<=X~nnL2g(f3t;>pjz#a
 `{^{6TBs5x~x(Z/R[VT@k"oW!][:+eW{Lj!*v{B/iCyOrx1x:|6}y_G@Z,qe$3)P\Da[_W!fTGW$Kr
 "pn#Y7SrNc5VAoh3qD5WHlWhC`]\n-W:Hl9Xj,6.-DPr&]NcLeP"a^Z83F-|QJ3|Y1Km)UB&p+ruM$
 jc
X-Anagram: Salad, Flat Up
X-Shakespearean-Insult: Thou mangled fen-sucked clack-dish!
X-Face-Info: Fly comedian from the Far Side
Reply-To: Paul Falstad <pjf@cts.com>
To: bde@freebsd.org
Subject: Re: bugs
Cc: hackers@freebsd.org
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: owner-hackers@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

Bruce Evans says:
| Subject: Re: bugs
| The ftruncate() works if a prototype for ftruncate() is in scope or if
| the `length' arg to ftruncate has the correct type (off_t = long long).
| Otherwise the top 32 bits of the length are random.  ftruncate() is
| prototyped in <unistd.h>.  You should also include <sys/types.h> before
| including <sys/mman.h>.  The above happens to work because <stdio.h>
| bogusly includes <sys/types.h>.  You should also include <fcntl.h>
| instead of <sys/file.h> except on old systems.

Sorry, bogus example again.  Our real code has a proper set of #includes.

| The strcpy() doesn't work unless PROT_WRITE is changed to
| `PROT_READ | PROT_WRITE', and this isn't because strcpy() reads its
| target - `buf[0] = 1' fails in the same way.

Interesting.  Well, that's a simple enough workaround...

Alex Nash says:
| Subject: Re: bugs
| >This works on all of our 10 existing UNIX platforms except BSDI and
| >Linux.  BSDI has the same problem with ftruncate, I think; Linux's
| >ftruncate works, but its mmap() appears to be totally broken, at least
| >in 1.2.13.
| 
| TRUNCATE(2)               FreeBSD Programmer's Manual              TRUNCATE(2)
| [...]
|  DESCRIPTION
|       Truncate() causes the file named by path or referenced by fd to be trun-
|       cated to at most length bytes in size.
|                ^^^^^^^

All I can say is that your ftruncate() seems to work right (i.e. the same
as everyone else) in spite of the documentation.  :-)

| As far as mmap is concerned, you cannot write beyond 'len' bytes as
| specified in the call to mmap.  [...]

Nor would I wish to.

--

Another problem: 

% vidcontrol VGA_80x50
Cannot set videomode: Invalid argument

VGA_80x25 and VGA_40x25 work fine, for what it's worth.


-- 
Paul Falstad, pjf@cts.com, 805-966-4935, http://www.ttinet.com/pjf/
    work: pf@software.com, 805-882-2470, http://www.software.com

Williams and Holland's Law:
	If enough data is collected, anything may be proven by
	statistical methods.