SLEEP(3) Library Functions Manual SLEEP(3)
sleep -- suspend process execution for interval of seconds
Standard C Library (libc, -lc)
sleep(unsigned int seconds);
The sleep() function suspends execution of the calling process until
either the number of seconds specified by seconds have elapsed or a
signal is delivered to the calling process and its action is to invoke a
signal-catching function or to terminate the process. The suspension
time may be longer than requested due to the scheduling of other activity
by the system.
If the sleep() function returns because the requested time has elapsed,
the value returned will be zero. If the sleep() function returns due to
the delivery of a signal, the value returned will be the unslept amount
(the request time minus the time actually slept) in seconds.
The sleep() function conforms to IEEE Std 1003.1-1990 (``POSIX.1'').
A sleep() function appeared in Version 7 AT&T UNIX.
NetBSD 6.1.5 June 4, 1993 NetBSD 6.1.5