| SLEEP(3) | Library Functions Manual | SLEEP(3) |
sleep —
#include <unistd.h>
unsigned int
sleep(unsigned
int seconds);
sleep() function suspends execution of the calling
process until either seconds seconds have elapsed or a
signal is delivered to the 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) by pausing for
seconds seconds or until a signal occurs.
Consequently, in this implementation, sleeping has no effect on the state of
process timers, and there is no special handling for
SIGALRM.
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.
sleep() function conforms to IEEE
Std 1003.1-1990 (“POSIX.1”).
sleep() system call first appeared in
Version 3 AT&T UNIX. In
Version 7 AT&T UNIX, it was removed and
replaced by a C library implementation based on
signal(3) and
alarm(3). For OpenBSD
2.1, it was reimplemented as a wrapper around the
nanosleep(2) system call.
| February 21, 2014 | OpenBSD-current |