NAME
sleep —
suspend process execution for
interval of seconds
LIBRARY
Standard C Library (libc, -lc)
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.
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 ALSO
nanosleep(2),
usleep(3)
STANDARDS
The
sleep() function conforms to
IEEE Std
1003.1-1990 (“POSIX.1”).
HISTORY
A
sleep() function appeared in
Version 7
AT&T UNIX.