fread ¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9799919799/functions/fread.html
Gnulib module: stdio-h, nonblocking
Portability problems fixed by Gnulib module stdio-h, together with module nonblocking:
errno being set to EINVAL instead of EAGAIN on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
MSVC_INVALID_PARAMETER_HANDLING is
HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING,
on some platforms:
MSVC 14.