NAME
setclock — set value of system-wide clock
SYNOPSIS
#include <sys/timers.h>
int setclock(int clock_type, struct timespec *tp);
DESCRIPTION
The
setclock()
function sets the current value
tp
of the specified system-wide clock,
clock_type.
setclock()
supports a
clock_type
of
TIMEOFDAY,
defined in
<sys/timers.h>,
which represents the time-of-day clock for the system.
For this clock, the values returned by
setclock()
represent the amount of time since the Epoch.
The calling process must have appropriate privileges to set the
TIMEOFDAY
clock.
APPLICATION USAGE
setclock()
is thread-safe and async-cancel-safe.
RETURN VALUE
Upon successful completion,
setclock()
returns a value of zero; otherwise it returns -1 and sets
errno
to indicate the error.
ERRORS
setclock()
fails if any of the following conditions are encountered:
- [EINVAL]
clock_type
does not specify a known system-wide clock, or
tp
either is outside the range for a given clock type,
or it specifies a nanosecond value less than zero
or greater than or equal to 1000 million.
- [EIO]
An error occurred while accessing the clock device.
- [EPERM]
The requesting process does not have the required appropriate privileges
to set the specified clock.
FILES
/usr/include/sys/timers.h
STANDARDS CONFORMANCE
setclock(): AES
