NTP_ADJTIME(2)NTP_ADJTIME(2)NAMEntp_adjtime - adjust local clock parameters
SYNOPSIS
#include <sys/timex.h>
int ntp_adjtime(struct timex *tptr);
DESCRIPTION
The ntp_adjtime() function adjusts the parameters used to discipline
the local clock, according to the values in the struct timex pointed to
by tptr. Before returning, it fills in the structure with the most
recent values kept in the kernel.
The adjustment is effected in part by speeding up or slowing down the
clock, as necessary, and in part by phase-locking onto a once-per sec‐
ond pulse (PPS) provided by a driver, if available.
struct timex {
uint32_t modes; /* clock mode bits (w) */
int32_t offset; /* time offset (us) (rw) */
int32_t freq; /* frequency offset (scaled ppm) (rw) */
int32_t maxerror; /* maximum error (us) (rw) */
int32_t esterror; /* estimated error (us) (rw) */
int32_t status; /* clock status bits (rw) */
int32_t constant; /* pll time constant (rw) */
int32_t precision; /* clock precision (us) (r) */
int32_t tolerance; /* clock frequency tolerance
(scaled ppm) (r) */
int32_t ppsfreq; /* pps frequency (scaled ppm) (r) */
int32_t jitter; /* pps jitter (us) (r) */
int32_t shift; /* interval duration (s) (shift) (r) */
int32_t stabil; /* pps stability (scaled ppm) (r) */
int32_t jitcnt; /* jitter limit exceeded (r) */
int32_t calcnt; /* calibration intervals (r) */
int32_t errcnt; /* calibration errors (r) */
int32_t stbcnt; /* stability limit exceeded (r) */
};
RETURN VALUES
Upon successful completion, ntp_adjtime() returns the current clock
state (see <sys/timex.h>). Otherwise, it returns −1 and sets errno to
indicate the error.
ERRORS
The ntp_adjtime() function will fail if:
EFAULT
The tptr argument is an invalid pointer.
EINVAL
The constant member of the structure pointed to by tptr is
less than 0 or greater than 30.
EPERM
The {PRIV_SYS_TIME} privilege is not asserted in the effec‐
tive set of the calling process.
SEE ALSOntp_gettime(2), privileges(5)
See the ntpd man page, delivered in the SUNWntpu package (not a SunOS
man page).
May 21, 2009 NTP_ADJTIME(2)
