sleep
—
suspend process execution for interval of seconds
Standard C Library (libc, -lc)
#include <unistd.h>
unsigned int
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.