int main()
{
char bufa[BUFSZ] = {'\0'},
bufb[BUFSZ];
size_t lena = 0,
mem = BUFSZ;
nmeamsg_t nm;
nmeabuf_t nb;
nmea_ctor(&nb, bufb, mem);
nmea_concat(&nb, ",2*23\n$CAREV,INIT,0.1.2.3.4*45\n$CA", 34);
nmea_scan(&nb, &nm);
nmea_debug(stderr, &nb);
lena = nmea_parse(bufa, mem, &nm);
if (0 == lena) return -1;
if (0 != strncmp(bufa, "$CAREV,INIT,0.1.2.3.4*45\n", lena)) return -1;
bufa[lena-1]='.';
printf("len=%ld msg=\"%s\"\n", lena, bufa);
nmea_scan(&nb, &nm);
nmea_debug(stderr, &nb);
return 0;
}
/* Collect NMEA sentences from the tty. */
int
nmeainput(int c, struct tty *tp)
{
struct nmea *np = (struct nmea *)tp->t_sc;
struct timespec ts;
int64_t gap;
long tmin, tmax;
switch (c) {
case '$':
nanotime(&ts);
np->pos = np->sync = 0;
gap = (ts.tv_sec * 1000000000LL + ts.tv_nsec) -
(np->lts.tv_sec * 1000000000LL + np->lts.tv_nsec);
np->lts.tv_sec = ts.tv_sec;
np->lts.tv_nsec = ts.tv_nsec;
if (gap <= np->gap)
break;
np->ts.tv_sec = ts.tv_sec;
np->ts.tv_nsec = ts.tv_nsec;
#ifdef NMEA_DEBUG
if (nmeadebug > 0) {
linesw[TTYDISC].l_rint('[', tp);
linesw[TTYDISC].l_rint('0' + np->gapno++, tp);
linesw[TTYDISC].l_rint(']', tp);
}
#endif
np->gap = gap;
/*
* If a tty timestamp is available, make sure its value is
* reasonable by comparing against the timestamp just taken.
* If they differ by more than 2 seconds, assume no PPS signal
* is present, note the fact, and keep using the timestamp
* value. When this happens, the sensor state is set to
* CRITICAL later when the GPRMC sentence is decoded.
*/
if (tp->t_flags & (TS_TSTAMPDCDSET | TS_TSTAMPDCDCLR |
TS_TSTAMPCTSSET | TS_TSTAMPCTSCLR)) {
tmax = lmax(np->ts.tv_sec, tp->t_tv.tv_sec);
tmin = lmin(np->ts.tv_sec, tp->t_tv.tv_sec);
if (tmax - tmin > 1)
np->no_pps = 1;
else {
np->ts.tv_sec = tp->t_tv.tv_sec;
np->ts.tv_nsec = tp->t_tv.tv_usec *
1000L;
np->no_pps = 0;
}
}
break;
case '\r':
case '\n':
if (!np->sync) {
np->cbuf[np->pos] = '\0';
nmea_scan(np, tp);
np->sync = 1;
}
break;
default:
if (!np->sync && np->pos < (NMEAMAX - 1))
np->cbuf[np->pos++] = c;
break;
}
/* pass data to termios */
return (linesw[TTYDISC].l_rint(c, tp));
}
