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Date: Wed, 13 Dec 2000 20:59:09 -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 changes #2
Cc: djgpp-workers AT delorie DOT com
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At 01:20 PM 12/13/00 +0200, Eli Zaretskii wrote:
 >On Tue, 12 Dec 2000, Peter J. Farley III wrote:
 >> I researched the question of a zero length to int21/5C.  RBIL is
 >> silent on the allowed values.  I will have to try setting the 
current
 >> position past EOF and then try locking to check the negative case,
 >> and setting it at EOF and try locking to check the zero case.
 >
 >You could make it part of the test program; that way, if something
 >changes in some future versions of DOS/Windows, we'd know.

That's what I had in mind.  It's in progress.

<filelength stuff snipped>
 >So I think it would be easier for you to dump filelength and use
 >llseek in all cases, including the FAT16 branch.  In other words,
 >expand filelength's guts inline and replace lseek with llseek.

Or just change filelength to use llseek.  Isn't that a better 
solution?  Of course, if the definition of filelength insists on a long 
result, wrong results can still be returned.  If that's the case, what 
about an "l" version of filelength (though "lfilelength" seems a bit of 
a cumbersome name, IMHO) which returns a long long?

 >> len = (unsigned long)filelength(fd) - cur_pos;
 >
 >I think this is unsafe because filelength uses lseek, which is
 >dangerous on FAT32 volumes.

Unless filelength uses llseek, of course.  Or unless we use 
lfilelength, which would of course use llseek.

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