ref: 88412aa050adddde5cacf3a45e914bad9a5d3e22
dir: /sys/src/cmd/aux/gps/util.c/
#include <u.h> #include <libc.h> #include "dat.h" Place nowhere = { Undef, Undef }; static void setlat(Place *p, double lat) { p->lat = lat; } static void setlon(Place *p, double lon) { p->lon = lon; } static int printlatlon(char *p, int n, double lat, char po, char ne) { char c; double d; int deg, min, sec; if(lat > 0) c = po; else if(lat < 0){ c = ne; lat = -lat; } else c = ' '; sec = 3600 * modf(lat, &d); deg = d; min = sec/60; sec = sec % 60; return snprint(p, n, "%#3.3d°%#2.2d′%#2.2d″%c", deg, min, sec, c); } int placeconv(Fmt *fp) { char str[256]; int n; Place pl; pl = va_arg(fp->args, Place); n = 0; n += printlatlon(str+n, sizeof(str)-n, pl.lat, 'N', 'S'); n += snprint(str+n, sizeof(str)-n, ", "); printlatlon(str+n, sizeof(str)-n, pl.lon, 'E', 'W'); return fmtstrcpy(fp, str); } int strtolatlon(char *p, char **ep, Place *pl) { double latlon; int neg = 0; while(*p == '0') p++; latlon = strtod(p, &p); if(latlon < 0){ latlon = -latlon; neg = 1; } if(*p == ':'){ p++; while(*p == '0') p++; latlon += strtod(p, &p)/60.0; if(*p == ':'){ p++; while(*p == '0') p++; latlon += strtod(p, &p)/3600.0; } } switch (*p++){ case 'N': case 'n': if(neg) latlon = -latlon; if(pl->lat != Undef) return -1; setlat(pl, latlon); break; case 'S': case 's': if(!neg) latlon = -latlon; if(pl->lat != Undef) return -1; setlat(pl, latlon); break; case 'E': case 'e': if(neg) latlon = -latlon; if(pl->lon != Undef) return -1; setlon(pl, latlon); break; case 'W': case 'w': if(!neg) latlon = -latlon; if(pl->lon != Undef) return -1; setlon(pl, latlon); break; case '\0': case ' ': case '\t': case '\n': p--; if(neg) latlon = -latlon; if(pl->lat == Undef){ setlat(pl, latlon); } else if(pl->lon == Undef){ latlon = -latlon; setlon(pl, latlon); } else return -1; break; default: return -1; } if(ep) *ep = p; return 0; } Place strtopos(char *p, char **ep) { Place pl = nowhere; if(strtolatlon(p, &p, &pl) < 0) return nowhere; while(*p == ' ' || *p == '\t' || *p == '\n') p++; if(strtolatlon(p, &p, &pl) < 0) return nowhere; if(ep) *ep = p; return pl; } void rtcset(long t) { static int fd = -1; long r; int n; char buf[32]; if(fd < 0 && (fd = open("#r/rtc", ORDWR)) < 0){ fprint(2, "Can't open #r/rtc: %r\n"); return; } n = read(fd, buf, sizeof buf - 1); if(n <= 0){ fprint(2, "Can't read #r/rtc: %r\n"); return; } buf[n] = '\0'; r = strtol(buf, nil, 0); if(r <= 0){ fprint(2, "ridiculous #r/rtc: %ld\n", r); return; } if(r - t > 1 || t - r > 0){ seek(fd, 0, 0); fprint(fd, "%ld", t); fprint(2, "correcting #r/rtc: %ld → %ld\n", r, t); } seek(fd, 0, 0); }