/**
* This outputs a list of timezone changes for the given timezone to the
* given file, up to the maximum year given. We compare this output with the
* output from 'vzic --dump-changes' to make sure that we are consistent.
* (vzic is the Olson timezone database to VTIMEZONE converter.)
*
* The output format is:
*
* Zone-Name [tab] Date [tab] Time [tab] UTC-Offset
*
* The Date and Time fields specify the time change in UTC.
*
* The UTC Offset is for local (wall-clock) time. It is the amount of time
* to add to UTC to get local time.
*/
int
icaltimezone_dump_changes (icaltimezone *zone,
int max_year,
FILE *fp)
{
static char *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
icaltimezonechange *zone_change;
int change_num;
char buffer[8];
/* Make sure the changes array is expanded up to the given time. */
icaltimezone_ensure_coverage (zone, max_year);
#if 0
printf ("Num changes: %i\n", zone->changes->num_elements);
#endif
change_num = 0;
for (change_num = 0; change_num < zone->changes->num_elements; change_num++) {
zone_change = icalarray_element_at (zone->changes, change_num);
if (zone_change->year > max_year)
break;
fprintf (fp, "%s\t%2i %s %04i\t%2i:%02i:%02i",
zone->location,
zone_change->day, months[zone_change->month - 1],
zone_change->year,
zone_change->hour, zone_change->minute, zone_change->second);
/* Wall Clock Time offset from UTC. */
format_utc_offset (zone_change->utc_offset, buffer);
fprintf (fp, "\t%s", buffer);
fprintf (fp, "\n");
}
return 1;
}
static bool
istrftime(char *buf, size_t size, char const *time_fmt,
struct tm const *tm, time_t t, char const *ab, char const *zone_name)
{
char *b = buf;
size_t s = size;
char const *f = time_fmt, *p;
for (p = f; ; p++)
if (*p == '%' && p[1] == '%')
p++;
else if (!*p
|| (*p == '%'
&& (p[1] == 'f' || p[1] == 'L' || p[1] == 'Q'))) {
size_t formatted_len;
size_t f_prefix_len = p - f;
size_t f_prefix_copy_size = p - f + 2;
char fbuf[100];
bool oversized = sizeof fbuf <= f_prefix_copy_size;
char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf;
memcpy(f_prefix_copy, f, f_prefix_len);
strcpy(f_prefix_copy + f_prefix_len, "X");
formatted_len = strftime(b, s, f_prefix_copy, tm);
if (oversized)
free(f_prefix_copy);
if (formatted_len == 0)
return false;
formatted_len--;
b += formatted_len, s -= formatted_len;
if (!*p++)
break;
switch (*p) {
case 'f':
formatted_len = format_quoted_string(b, s, zone_name);
break;
case 'L':
formatted_len = format_local_time(b, s, tm);
break;
case 'Q':
{
bool show_abbr;
int offlen = format_utc_offset(b, s, tm, t);
if (! (0 <= offlen && (size_t)offlen < s))
return false;
show_abbr = strcmp(b, ab) != 0;
b += offlen, s -= offlen;
if (show_abbr) {
char const *abp;
size_t len;
if (s <= 1)
return false;
*b++ = '\t', s--;
for (abp = ab; is_alpha(*abp); abp++)
continue;
len = (!*abp && *ab
? (size_t)snprintf(b, s, "%s", ab)
: format_quoted_string(b, s, ab));
if (s <= len)
return false;
b += len, s -= len;
}
formatted_len = (tm->tm_isdst
? snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst)
: 0);
}
break;
}
if (! (formatted_len < s))
return false;
b += formatted_len, s -= formatted_len;
f = p + 1;
}
*b = '\0';
return true;
}
