Re: [bug-gv] Fwd: Bug#497044: gv: does not work properly with files >~2gb

[Markus Steinborn]

Hi Bernhard,

On Mon, 1 Sep 2008, Bernhard R. Link wrote:

> ----- Forwarded message from Marc Lehmann <debian-reportbug at plan9.de> -----
> [...]
> ----- End forwarded message -----

Thanks for forwarding this bug report. Now it is present in the GNU 
archives.

> Fixing this looks a bit complicated (at least on 32 bit architectures,
> on 64 bit architectures long is a bit longer and already helps).
>
> I'd suggest to start with adding AC_SYS_LARGEFILE to configure.ac.
> This tells autoconf that we want off_t to be 64 bit always. (This
> is the default on things like BSDs anyway AFAIK, but Linux has still
> quite "backward-compatible" defaults).[1]

On Saturday, I startet to make it working on X86_64 (by replacing chosen 
int's by long's). It's working now on X86_64 (by a quick test).

> Then it needs to make sure to actually use off_t. File descriptor
> based functions usually use them, but file stream based not (problem
> are fseek and ftell, I guess).

As it is working now on X86_64, I can be sure that all relevant variables 
are of type long and so I can grep for them.

> There are fseeko and ftello to help here (things using them need to be
> off_t (or long long), though), those are relatively new functions
> though. (my manpage says "SUSv2, POSIX.1-2001"), though this might
> perhaps need a fallback to use fseek and ftell there for older
> systems...

That is actually in progess - with some extension: The configure script 
chooses wheather to

* use   off64_t, fopen64, fseeko64, ftello64 and stat64

* use   off_t, fopen, fseeko, ftello and stat

* use   long, fopen, fseek, ftell and stat (as fallback).


I am not sure if the first option is really needed, but it does not hurt 
anyway. You can expect a CVS checkin with that changes quite soon, 
probably today.

Greetings

Markus Steinborn