Is u_char a standard?

Question

Just curious if u_char is a standard. I\'ve always used it assuming it was defined along with uintX_t types and so on. But am seeing some of our code base transition from

Answer 1

The string u_char does not appear in this draft of the C standard:

http://www.open-std.org/jtc1/sc22/WG14/www/docs/n1256.pdf

It's not required by POSIX either, as far as I know.

I think it's in BSD (sys/types.h), and Windows (winsock.h). I would not consider either one to be "a standard" - they aren't formal standards, and they certainly aren't part of standard C, but they are clearly defined and documented.