adjtimex(2) human readable print out utility

print_adjtimex.c

/* This is adjtimex(2) human readable print out utility.
 *
 * The program has BSD 2-clause license which also known as "Simplified
 * BSD License" or "FreeBSD License".
 *
 * Copyright 2018- Sami Kerola. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *    1. Redistributions of source code must retain the above copyright
 *	 notice, this list of conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright
 *	 notice, this list of conditions and the following disclaimer in the
 *	 documentation and/or other materials provided with the
 *	 distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR AND CONTRIBUTORS OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are
 * those of the authors and should not be interpreted as representing
 * official policies, either expressed or implied, of Sami Kerola.
 *
 * https://gist.github.com/kerolasa/88ee7a56fc58749b3c64ac8605c92da1
 */

#include <stdio.h>
#include <sys/timex.h>

int main(int argc, char **argv)
{
	struct timex tx = { 0 };
	int ret;
	int nano;

	ret = ntp_adjtime(&tx);
	nano = (tx.status & STA_NANO);

	printf("ntp_adjtime() return value: ");
	switch(ret) {
	case TIME_OK:
		printf("TIME_OK\n");
		break;
	case TIME_INS:
		printf("TIME_INS a leap second will be added at the end of the UTC day\n");
		break;
	case TIME_DEL:
		printf("TIME_DEL a leap second will be deleted at the end of the UTC day\n");
		break;
	case TIME_OOP:
		printf("TIME_OOP leap-second insertion or deletion has been completed\n");
		break;
	case TIME_ERROR:
		printf("TIME_ERROR system clock is not synchronized to a reliable server\n");
		break;
	default:
		printf("unexpected return value: %d\n", ret);
		break;
	}

	printf("%20ld Time offset in %sseconds\n", tx.offset, nano ? "nano" : "micro");
	printf("%20ld Frequency offset\n", tx.freq);
	printf("%20ld Maximum error microseconds\n", tx.maxerror);
	printf("%20ld Estimated error microseconds\n", tx.esterror);
	printf("%20d Clock status\n", tx.status);

	if (tx.status & STA_PLL)	{printf("%*s ^ phase-locked loop updates\n", 21, "");}
	if (tx.status & STA_PPSFREQ)	{printf("%*s ^ pulse-per-second frequency discipline\n", 21, "");}
	if (tx.status & STA_PPSTIME)	{printf("%*s ^ pulse-per-second time discipline\n", 21, "");}
	if (tx.status & STA_FLL)	{printf("%*s ^ frequency-lock mode\n", 21, "");}

	if (tx.status & STA_INS)	{printf("%*s ^ insert leap\n", 21, "");}
	if (tx.status & STA_DEL)	{printf("%*s ^ delete leap\n", 21, "");}
	if (tx.status & STA_UNSYNC)	{printf("%*s ^ clock unsynchronized\n", 21, "");}
	if (tx.status & STA_FREQHOLD)	{printf("%*s ^ hold frequency\n", 21, "");}

	if (tx.status & STA_PPSSIGNAL)	{printf("%*s ^ PPS signal present\n", 21, "");}
	if (tx.status & STA_PPSJITTER)	{printf("%*s ^ PPS signal jitter exceeded\n", 21, "");}
	if (tx.status & STA_PPSWANDER)	{printf("%*s ^ PPS signal wander exceeded\n", 21, "");}
	if (tx.status & STA_PPSERROR)	{printf("%*s ^ PPS signal calibration error\n", 21, "");}

	if (tx.status & STA_CLOCKERR)	{printf("%*s ^ clock hardware fault\n", 21, "");}
	if (tx.status & STA_NANO)	{printf("%*s ^ nanosecond resolution\n", 21, "");}
	if (tx.status & STA_MODE)	{printf("%*s ^ frequency-locked loop mode\n", 21, "");}
	if (tx.status & STA_CLK)	{printf("%*s ^ ADJ_TICK in use\n", 21, "");}

	printf("%20ld PLL (phase-locked loop) time constant\n", tx.constant);
	printf("%20ld Clock precision microseconds\n", tx.precision);
	printf("%20ld Clock frequency tolerance\n", tx.tolerance);
	printf("%ld.%09ld Current time\n", tx.time.tv_sec, tx.time.tv_usec);
	printf("%20ld Microseconds between clock ticks\n", tx.tick);
	if (tx.status & STA_PPSFREQ || tx.status & STA_PPSTIME) {
		printf("%20ld PPS (pulse per second) frequency\n", tx.ppsfreq);
		printf("%20ld PPS jitter (read-only); %sseconds\n", tx.jitter, nano ? "nano" : "micro");
		printf("%20d PPS interval duration\n", tx.shift);
		printf("%20ld PPS stability\n", tx.stabil);
		printf("%20ld PPS count of jitter limit exceeded events\n", tx.jitcnt);
		printf("%20ld PPS count of calibration intervals\n", tx.calcnt);
		printf("%20ld PPS count of calibration errors\n", tx.errcnt);
		printf("%20ld PPS count of stability limit exceeded events\n", tx.stbcnt);
	}
	printf("%20d TAI offset\n", tx.tai);

	return 0;
}