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/* See LICENSE file for copyright and license details. */
#include "common.h"
static char *
get_timezone(struct libgeome_context *ctx, int *env_determined_out)
{
const char *tzdir;
const char *tz;
char *tzbuf = NULL;
char *ret;
size_t tzdirlen;
tz = getenv("TZ");
*env_determined_out = !!tz;
if (!tz) {
tzdir = getenv("TZDIR");
if (!tzdir)
tzdir = TZDIR;
tz = tzbuf = libgeome_util_areadlink(ctx, TZFILE);
if (!tz)
return NULL;
tzdirlen = strlen(tzdir);
if (!strncmp(tz, tzdir, tzdirlen) && tz[tzdirlen] == '/') {
tz = &tz[tzdirlen];
while (*tz == '/')
tz++;
}
}
ret = strdup(tz);
if (!ret)
ctx->print_error(ctx, "strdup: %s\n", strerror(errno));
free(tzbuf);
return ret;
}
static int
get_timezone_location3(struct libgeome_context *ctx, const char *tz, const char *tabfile, struct location *location_out)
{
const char *tzdir, *coords;
char *path, *line = NULL, *p;
size_t size = 0, tzlen = strlen(tz);
int lat_sign, lat_degrees, lat_minutes, lat_seconds = 0;
int lon_sign, lon_degrees, lon_minutes, lon_seconds = 0;
ssize_t len;
FILE *f;
tzdir = getenv("TZDIR");
if (!tzdir)
tzdir = TZDIR;
path = malloc(strlen(tzdir) + strlen(tabfile) + sizeof("/"));
if (!path) {
ctx->print_error(ctx, "malloc: %s\n", strerror(errno));
return -1;
}
stpcpy(stpcpy(stpcpy(path, tzdir), "/"), tabfile);
f = fopen(path, "r");
if (!f) {
if (errno == ENOENT)
ctx->print_debug(ctx, "fopen %s r: %s\n", path, strerror(errno));
else
ctx->print_error(ctx, "fopen %s r: %s\n", path, strerror(errno));
free(path);
return -1;
}
again:
while (len = getline(&line, &size, f), len >= 0) {
p = line;
for (;; p++) {
if (!*p || *p == '\r' || *p == '\n' || *p == '#')
goto next_line;
if (*p == '\t')
break;
}
coords = ++p;
for (;; p++) {
if (!*p || *p == '\r' || *p == '\n' || *p == '#')
goto next_line;
if (*p == '\t')
break;
}
*p++ = '\0';
if (strncmp(p, tz, tzlen))
goto next_line;
p = &p[tzlen];
if (*p && *p != '\r' && *p != '\n' && *p != '#' && *p != '\t')
goto next_line;
goto found_coords;
next_line:;
}
if (!feof(f)) {
if (errno == EINTR) {
clearerr(f);
goto again;
}
ctx->print_error(ctx, "getline %s: %s\n", path, strerror(errno));
}
ctx->print_debug(ctx, "entry for timezone %s not found in %s\n", tz, path);
free(line);
free(path);
fclose(f);
return -1;
bad_coords:
ctx->print_debug(ctx, "malformatted coordinates for %s in %s\n", tz, path);
free(line);
free(path);
fclose(f);
return -1;
found_coords:
if (coords[0] != '+' && coords[0] != '-')
goto bad_coords;
if (!isdigit(coords[1]) || !isdigit(coords[2]))
goto bad_coords;
if (!isdigit(coords[3]) || !isdigit(coords[4]))
goto bad_coords;
lat_sign = coords[0] == '-' ? -1 : +1;
lat_degrees = (coords[1] & 15) * 10 + (coords[2] & 15);
lat_minutes = (coords[3] & 15) * 10 + (coords[4] & 15);
coords = &coords[5];
if (isdigit(coords[0]) && isdigit(coords[1])) {
lat_seconds = (coords[0] & 15) * 10 + (coords[1] & 15);
coords = &coords[2];
}
if (coords[0] != '+' && coords[0] != '-')
goto bad_coords;
if (!isdigit(coords[1]) || !isdigit(coords[2]) || !isdigit(coords[3]))
goto bad_coords;
if (!isdigit(coords[4]) || !isdigit(coords[5]))
goto bad_coords;
lon_sign = coords[0] == '-' ? -1 : +1;
lon_degrees = (coords[1] & 15) * 100 + (coords[2] & 15) * 10 + (coords[3] & 15);
lon_minutes = (coords[4] & 15) * 10 + (coords[5] & 15);
coords = &coords[6];
if (isdigit(coords[0]) && isdigit(coords[1])) {
lon_seconds = (coords[0] & 15) * 10 + (coords[1] & 15);
coords = &coords[2];
}
if (*coords)
goto bad_coords;
if (lat_degrees > 90 || lon_degrees > 180)
goto bad_coords;
if (lat_minutes >= 60 || lon_minutes >= 60)
goto bad_coords;
if (lat_seconds >= 60 || lon_seconds >= 60)
goto bad_coords;
if (lat_degrees == 90 && lat_minutes + lat_seconds)
goto bad_coords;
if (lon_degrees == 180 && lon_minutes + lon_seconds)
goto bad_coords;
location_out->latitude = (double)lat_degrees;
location_out->latitude += (double)lat_minutes / 60;
location_out->latitude += (double)lat_seconds / 3600;
location_out->latitude *= (double)lat_sign;
location_out->longitude = (double)lon_degrees;
location_out->longitude += (double)lon_minutes / 60;
location_out->longitude += (double)lon_seconds / 3600;
location_out->longitude *= (double)lon_sign;
free(line);
free(path);
fclose(f);
return 0;
}
static int
get_timezone_location(struct libgeome_context *ctx, const char *tz, struct location *location_out)
{
if (!get_timezone_location3(ctx, tz, "zone1970.tab", location_out))
return 0;
if (!get_timezone_location3(ctx, tz, "zone.tab", location_out))
return 0;
if (!get_timezone_location3(ctx, tz, "zonenow.tab", location_out))
return 0;
return -1;
}
int
libgeome_get_from_timezone(struct libgeome_context *ctx, struct libgeome_data *out)
{
struct location location;
char *tz;
tz = get_timezone(ctx, &(int){0});
if (!tz)
return -1;
if (get_timezone_location(ctx, tz, &location)) {
free(tz);
return -1;
}
free(tz);
out->requested_data &= LIBGEOME_DATUM_LATITUDE | LIBGEOME_DATUM_LONGITUDE;
if (out->requested_data) {
if (out->requested_data & LIBGEOME_DATUM_LATITUDE)
out->latitude = location.latitude;
if (out->requested_data & LIBGEOME_DATUM_LONGITUDE)
out->longitude = location.longitude;
}
return 0;
}
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