A list of var types with endianness - operating system ?

[tonnot]

I'm looking for a list in which I can see var types and the endianness used clasiffied by operating system and /or processor.
Any link ?

Can I use a specific kind of var type endianness independent ?

Thanks

[Disch]

Endianness only matters when you attempt to access a variable by a sequence of bytes rather than in its entirety. For all other purposes it does not matter.

If you use a variable as a whole, it doesn't matter what endianness you're system is using.


That said, all var types larger than 1 byte are subject to system endianness. So really the only type that isn't subject is char and unsigned char (and possibly bool).

As for a list of machines that are of a specific endianness, I couldn't help you there. Maybe someone else can chime in.

[helios]

The endianness depends on the CPU. An easy way to find it is to look at the Wikipedia article. For example,
http://en.wikipedia.org/wiki/X86
http://en.wikipedia.org/wiki/ARM
http://en.wikipedia.org/wiki/SPARC
http://en.wikipedia.org/wiki/PowerPC

Can I use a specific kind of var type endianness independent ?

Not in any efficient way. Why would you care about this, though?

EDIT:
Additionally, there are ways to check the endianness at run time.

bool is_little_endian(){
    int v=0x1234;
    return *(char *)&v==0x34;
}

[tonnot]

And the Operating system ?
Windows / linux / unix / mac-os ??
Thanks

[helios]

The OS can only follow the endianness enforced by the CPU. You can't run a little endian OS on a big endian CPU.