NAME
sleep
- suspend process execution for interval of seconds
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
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
ISO/IEC 9945-1:1990 (``POSIX.1'') .
HISTORY
A
sleep(
)
function appeared in
Version 7 AT&T UNIX
.