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   ntp_gettimex    ( 3 )

получить временные параметры (интерфейс демона NTP) (get time parameters (NTP daemon interface))

Имя (Name)

ntp_gettime, ntp_gettimex  - get time parameters (NTP daemon
       interface)

Синопсис (Synopsis)

#include <sys/timex.h>

int ntp_gettime(struct ntptimeval *ntv); int ntp_gettimex(struct ntptimeval *ntv);


Описание (Description)

Both of these APIs return information to the caller via the ntv
       argument, a structure of the following type:

struct ntptimeval { struct timeval time; /* Current time */ long maxerror; /* Maximum error */ long esterror; /* Estimated error */ long tai; /* TAI offset */

/* Further padding bytes allowing for future expansion */ };

The fields of this structure are as follows:

time The current time, expressed as a timeval structure:

struct timeval { time_t tv_sec; /* Seconds since the Epoch */ suseconds_t tv_usec; /* Microseconds */ };

maxerror Maximum error, in microseconds. This value can be initialized by ntp_adjtime(3), and is increased periodically (on Linux: each second), but is clamped to an upper limit (the kernel constant NTP_PHASE_MAX, with a value of 16,000).

esterror Estimated error, in microseconds. This value can be set via ntp_adjtime(3) to contain an estimate of the difference between the system clock and the true time. This value is not used inside the kernel.

tai TAI (Atomic International Time) offset.

ntp_gettime() returns an ntptimeval structure in which the time, maxerror, and esterror fields are filled in.

ntp_gettimex() performs the same task as ntp_gettime(), but also returns information in the tai field.


Возвращаемое значение (Return value)

The return values for ntp_gettime() and ntp_gettimex() are as for
       adjtimex(2).  Given a correct pointer argument, these functions
       always succeed.

Версии (Versions)

The ntp_gettime() function is available since glibc 2.1.  The
       ntp_gettimex() function is available since glibc 2.12.

Атрибуты (Attributes)

For an explanation of the terms used in this section, see
       attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface Attribute Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │ntp_gettime(), ntp_gettimex() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

ntp_gettime() is described in the NTP Kernel Application Program
       Interface.  ntp_gettimex() is a GNU extension.

Смотри также (See also)

adjtimex(2), ntp_adjtime(3), time(7)

NTP "Kernel Application Program Interface" ⟨http://www.slac.stanford.edu/comp/unix/package/rtems/src/ssrlApps/ntpNanoclock/api.htm⟩