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Date: Wed, 29 Nov 2000 23:04:24 -0500
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
From: "Peter J. Farley III" <pjfarley AT banet DOT net>
Subject: Re: Locking fcntl() and flock() patches
Cc: djgpp-workers AT delorie DOT com
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At 10:13 AM 11/29/00 +0200, Eli Zaretskii wrote:
 >On Tue, 28 Nov 2000, Peter J. Farley III wrote:
 >
 >> Ah!  I misunderstood.  Then, how about just the part of the comment 

 >> that the value for 21h/33 was changed from EPERM to EACCES for
 >> fcntl?  Is that more appropriate?
 >
 >That's exactly what I had in mind.

OK, will do.

<Snipped>
 >> Well, I think on systems that support large files, type "off_t" is
 >> probably a "long long", whatever that means on those systems.
 >
 >No, I don't think so.  Changing off_t to long long would break lots 
of
 >existing code which assumes off_t and ssize_t are compatible.

Well, if that's the case then I don't know what else to say.  Obviously 
we *can* widen them, but I don't have the expertise to say if we 
*should* do so.  What we need here is someone with experience on a 
system that actually has the capability.

 >>>> How would one go about determining whether an arbitrary
 >>>> combination "covered the whole file"?
 >>>
 >>> You use lseek to seek to the starting offset, then look at lseek's
 >>> return value and compare it with zero.  Then you lseek to the end
 >>> of the region and compare lseek's return value with the result of
 >>> "lseek(fd,0,SEEK_END);".
 >>
 >> I also assume you meant to say "llseek" there, right?
 >
 >Yes.

Thanks for the confirmation.  Well, If we are going to allow F_RDLCK's 
that cover the whole file, I guess that's not too much code to add.  I 
won't add it until we determine whether we should do them at 
all.  (Please see my other reply on this).

---------------------------------------------------------
Peter J. Farley III (pjfarley AT dorsai DOT org OR
                      pjfarley AT banet DOT net)