usleep ¶Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/usleep.html
Portability problems fixed by Gnulib:
usleep rejects attempts to sleep longer than 1
second, as allowed by POSIX:
NetBSD 10.0, mingw.
Portability problems not fixed by Gnulib:
usleep function may interfere with the program’s
use of the SIGALRM signal. On Linux, it doesn’t; on other platforms,
it may.
usleep may sleep for less than the indicated duration:
Cygwin 3.5.3.