SLEEP(3) OpenBSD Programmer's Manual SLEEP(3)NAMEsleep - suspend process execution for interval of seconds
SYNOPSIS
#include <unistd.h>
unsigned int
sleep(unsigned int seconds);
DESCRIPTION
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.
This function is implemented using nanosleep(2); it requires one system
call each time it is invoked. A similar but less compatible function can
be obtained with a single select(2); such a function would not restart
after signals, and also does not interfere with other uses of
setitimer(2) (not that sleep() interferes with interval timers anymore).
RETURN VALUES
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.
SEE ALSOsleep(1), nanosleep(2), select(2), setitimer(2), sigaction(2),
sigsuspend(2), alarm(3), pause(3), usleep(3)STANDARDS
The sleep() function conforms to IEEE Std 1003.1-1990 (``POSIX'').
HISTORY
A sleep() function appeared in Version 7 AT&T UNIX.
OpenBSD 4.9 October 24, 2008 OpenBSD 4.9
