Re: FW: 64 bit or 32 bit

[Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx>]

Benoit Rouits wrote:

> > > > How can I tell if a given system is running a 32bit krnel or a 64bit
> > > > kernel. I a system capable of running either, but I cannot figure
> > > > out which kernel is installed on it.
> > > 
> > > just make a C program like this:
> > > 
> > > int main()
> > > {
> > > 	printf("address bus is %d bytes\n",sizeof(void*));
> > > }
> > > and compile it with cc then run it.
> > > If it prints 8, it is a 64 bit OS, if it prints 4, it is a 32 bit OS.
> > 
> > That tells you which architecture the program was compiled for, not
> > which architecture the kernel was compiled for. x86_64 can run both
> > 32- and 64-bit code.
> 
> well, if we have a 64-bit kernel /and/ a compiler for 64 bits
> architectures, i think that a long int must be 8 bytes, no ?

If you compile the code into a 64-bit executable, it will either print
"address bus is 8 bytes" or refuse to run.

If you compile the code into a 32-bit executable, it will print
"address bus is 4 bytes" regardless of whether you run it on a 32- or
64-bit system.

-- 
Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx>
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