On 01/25/2013 01:39 PM, Marco Schuster wrote:
> Hi all,
>
> I'm currently writing a php-program to process certain special binary
> files, which include 32-bit offsets which I need to read and
> manipulate. The problem is that PHPs int type is only 31-bit because
> they have sign information. Sure, I could use the GMP/bcmath stuff,
> but that isn't really an option because of performance and the fact
> that I'd have to use bc* functions everywhere, and the code is already
> complex enough. Because I need to do maths and, later on, file
> accesses at positions > 2GB, with them and not just print,
> sprintf("%u",$val) is not sufficient, too.
>
> Switching to 64-bit doesn't help in my case, as the program interfaces
> with external windows-only dependencies and the PHP x64 build doesn't
> do 64-bit ints at the moment.
>
> Would it be possible to extend the PHP engine and add a "uint" native
> type which allows handling of full 32-bit values and if yes, is there
> any documentation about the parts of the engine I need to modify? The
> PHP internals manual doesn't have much content and the Zend / main
> directories in the source code lack useful information, too.
No, this isn't something a quick patch will solve for you. It would
require changes throughout all of PHP and all the extensions.
For display purposes you can easily print these unsigned using
s/printf('%u',$val) and manipulation is possible too depending on what
sort of things you are trying to do to them.
If that isn't enough, writing a little custom extension to handle your
special case for these offsets is way way easier than modifying PHP to
add a new type.
-Rasmus
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