When does Endianness become a factor?

Question

Endianness from what I understand, is when the bytes that compose a multibyte word differ in their order, at least in the most typical case. So that an 16-bit integer may b

Answer 1

For the record, if you're transferring data between devices you should pretty much always use network-byte-ordering with ntohl, htonl, ntohs, htons. It'll convert to the network byte order standard for Endianness regardless of what your system and the destination system use. Of course, both systems shoud be programmed like this - but they usually are in networking scenarios.

Answer 2

Endianness is ALWAYS an issue. Some will say that if you know that every host connected to the network runs the same OS, etc, then you will not have problems. This is true until it isn't. You always need to publish a spec that details the EXACT format of on-wire data. It can be any format you want, but every endpoint needs to understand the format and be able to interpret it correctly.

In general, protocols use big-endian for numerical values, but this has limitations if everyone isn't IEEE 754 compatible, etc. If you can take the overhead, then use an XDR (or your favorite solution) and be safe.