Bruno Haible via Gnulib discussion list <[email protected]> writes: > Paul Eggert wrote: >> + int _r = fputc (Byte, P); \ >> + if (_r < 0) \ >> + return _r; \ > > When fputc fails, it returns EOF, which POSIX [1] guarantees to be negative. > But in fprintftime.h we make the stronger assertion that the return value > is == -1, not only negative. (Although, admittedly, all existing platforms > define EOF to -1 or (-1).)
The POSIX requirement is adopted from ISO C. See C23 § 7.24.1 or C99 § 7.19.1. Collin
