Re: Lua 5.3.1: file:seek() and files larger than 2 GB

[Philipp Janda <siffiejoe@...>]

Am 04.10.2015 um 07:21 schröbte Paul K:
> Hi All,

Hi!

> I saw a discussion some time ago on making file seek/tell to work with
> large (>2GB) files on Windows 32bit:
> http://lua-users.org/lists/lua-l/2015-05/msg00370.html
>
> I used Roberto's suggestion, but modified it slightly as the linker
> couldn't find fseeko and ftello (I replaced them with fseeko64 and
> ftello64):
>
> #if defined(liolib_c) && defined(__MINGW32__)
> #include <sys/types.h>
> #define l_fseek(f,o,w) fseeko64(f,o,w)
> #define l_ftell(f) ftello64(f)
> #define l_seeknum off_t

You should use `off64_t` here instead. `off_t` is typedefed as `long` 
which is 32 bit on Windows.

> #endif
>
> I compiled Lua 5.3.1 with mingw 4.8.1 and everything has been working
> as expected, but I only tested it on one machine. Is it the right way
> to apply this fix?
>
> I initially was confused by the message from f:seek("end"), which
> returned (on a large file):
>
> nil    "Invalid argument"    22
>
> f:seek("set", -1) returned the same result. I think it's a bit
> misleading as there is nothing wrong with the arguments I passed.

Works fine here! Maybe your lua.exe is picking up the wrong DLL?!

> Paul.

Philipp