Files
2026-02-23 05:31:02 +01:00

236 lines
6.1 KiB
C

/* copyright (c) 2022 - 2026 grunfink et al. / MIT license */
#ifndef _XS_TIME_H
#define _XS_TIME_H
#include <time.h>
xs_str *xs_str_time(time_t t, const char *fmt, int local);
#define xs_str_localtime(t, fmt) xs_str_time(t, fmt, 1)
#define xs_str_utctime(t, fmt) xs_str_time(t, fmt, 0)
#define xs_str_iso_date(t) xs_str_time(t, "%Y-%m-%dT%H:%M:%SZ", 0)
time_t xs_parse_iso_date(const char *iso_date, int local);
time_t xs_parse_time(const char *str, const char *fmt, int local);
#define xs_parse_localtime(str, fmt) xs_parse_time(str, fmt, 1)
#define xs_parse_utctime(str, fmt) xs_parse_time(str, fmt, 0)
xs_str *xs_str_time_diff(time_t time_diff);
xs_list *xs_tz_list(void);
int xs_tz_offset(const char *tz);
#ifdef XS_IMPLEMENTATION
xs_str *xs_str_time(time_t t, const char *fmt, int local)
/* returns a string with a formated time */
{
struct tm tm;
char tmp[64];
if (t == 0)
t = time(NULL);
if (local)
localtime_r(&t, &tm);
else
gmtime_r(&t, &tm);
strftime(tmp, sizeof(tmp), fmt, &tm);
return xs_str_new(tmp);
}
xs_str *xs_str_time_diff(time_t time_diff)
/* returns time_diff in seconds to 'human' units (d:hh:mm:ss) */
{
int secs = time_diff % 60;
int mins = (time_diff /= 60) % 60;
int hours = (time_diff /= 60) % 24;
int days = (time_diff /= 24);
return xs_fmt("%d:%02d:%02d:%02d", days, hours, mins, secs);
}
char *strptime(const char *s, const char *format, struct tm *tm);
time_t xs_parse_time(const char *str, const char *fmt, int local)
{
time_t t = 0;
#ifndef WITHOUT_STRPTIME
struct tm tm = {0};
strptime(str, fmt, &tm);
/* try to guess the Daylight Saving Time */
if (local)
tm.tm_isdst = -1;
t = local ? mktime(&tm) : timegm(&tm);
#endif /* WITHOUT_STRPTIME */
return t;
}
time_t xs_parse_iso_date(const char *iso_date, int local)
/* parses a YYYY-MM-DDTHH:MM:SS date string */
{
time_t t = 0;
#ifndef WITHOUT_STRPTIME
t = xs_parse_time(iso_date, "%Y-%m-%dT%H:%M:%S", local);
#else /* WITHOUT_STRPTIME */
struct tm tm = {0};
if (sscanf(iso_date, "%d-%d-%dT%d:%d:%d",
&tm.tm_year, &tm.tm_mon, &tm.tm_mday,
&tm.tm_hour, &tm.tm_min, &tm.tm_sec) == 6) {
tm.tm_year -= 1900;
tm.tm_mon -= 1;
if (local)
tm.tm_isdst = -1;
t = local ? mktime(&tm) : timegm(&tm);
}
#endif /* WITHOUT_STRPTIME */
return t;
}
/** timezones **/
/* intentionally dead simple */
struct {
const char *tz; /* timezone name */
float h_offset; /* hour offset */
} xs_tz[] = {
{ "UTC", 0 },
{ "WET (Western European Time)", 0 },
{ "WEST (Western European Summer Time)", 1 },
{ "CET (Central European Time)", 1 },
{ "CEST (Central European Summer Time)", 2 },
{ "EET (Eastern European Time)", 2 },
{ "EEST (Eastern European Summer Time)", 3 },
{ "MSK (Moskow Time Zone)", 3 },
{ "EST (Eastern Time Zone)", -5 },
{ "AST (Atlantic Time Zone)", -4 },
{ "ADT (Atlantic Daylight Time Zone)", -3 },
{ "CST (Central Time Zone)", -6 },
{ "CDT (Central Daylight Time Zone)", -5 },
{ "MST (Mountain Time Zone)", -7 },
{ "MDT (Mountain Daylight Time Zone)", -6 },
{ "PST (Pacific Time Zone)", -8 },
{ "PDT (Pacific Daylight Time Zone)", -7 },
{ "AKST (Alaska Time Zone)", -9 },
{ "AKDT (Alaska Daylight Time Zone)", -8 },
{ "China Time Zone", 8 },
{ "IST (Indian Standard Time)", 5.5 },
{ "IDT (Israel Daylight Standard Time)", 3 },
{ "WIB (Western Indonesia Time)", 7 },
{ "WITA (Central Indonesia Time)", 8 },
{ "WIT (Eastern Indonesia Time)", 9 },
{ "AWST (Australian Western Time)", 8 },
{ "ACST (Australian Eastern Time)", 9.5 },
{ "ACDT (Australian Daylight Eastern Time)", 10.5 },
{ "AEST (Australian Eastern Time)", 10 },
{ "AEDT (Australian Daylight Eastern Time)", 11 },
{ "NZST (New Zealand Time)", 12 },
{ "NZDT (New Zealand Daylight Time)", 13 },
{ "UTC", 0 },
{ "UTC+1", 1 },
{ "UTC+2", 2 },
{ "UTC+3", 3 },
{ "UTC+4", 4 },
{ "UTC+5", 5 },
{ "UTC+6", 6 },
{ "UTC+7", 7 },
{ "UTC+8", 8 },
{ "UTC+9", 9 },
{ "UTC+10", 10 },
{ "UTC+11", 11 },
{ "UTC+12", 12 },
{ "UTC-1", -1 },
{ "UTC-2", -2 },
{ "UTC-3", -3 },
{ "UTC-4", -4 },
{ "UTC-5", -5 },
{ "UTC-6", -6 },
{ "UTC-7", -7 },
{ "UTC-8", -8 },
{ "UTC-9", -9 },
{ "UTC-10", -10 },
{ "UTC-11", -11 },
{ "UTC-12", -12 },
{ "UTC-13", -13 },
{ "UTC-14", -14 },
{ "GMT", 0 },
{ "GMT+1", 1 },
{ "GMT+2", 2 },
{ "GMT+3", 3 },
{ "GMT+4", 4 },
{ "GMT+5", 5 },
{ "GMT+6", 6 },
{ "GMT+7", 7 },
{ "GMT+8", 8 },
{ "GMT+9", 9 },
{ "GMT+10", 10 },
{ "GMT+11", 11 },
{ "GMT+12", 12 },
{ "GMT-1", -1 },
{ "GMT-2", -2 },
{ "GMT-3", -3 },
{ "GMT-4", -4 },
{ "GMT-5", -5 },
{ "GMT-6", -6 },
{ "GMT-7", -7 },
{ "GMT-8", -8 },
{ "GMT-9", -9 },
{ "GMT-10", -10 },
{ "GMT-11", -11 },
{ "GMT-12", -12 },
{ "GMT-13", -13 },
{ "GMT-14", -14 },
{ NULL, 0 }
};
xs_list *xs_tz_list(void)
/* returns the list of supported timezones */
{
xs_list *l = xs_list_new();
for (int n = 0; xs_tz[n].tz != NULL; n++)
l = xs_list_append(l, xs_tz[n].tz);
return l;
}
int xs_tz_offset(const char *tz)
/* returns the offset in seconds from the specified Time Zone to UTC */
{
for (int n = 0; xs_tz[n].tz != NULL; n++) {
if (strcmp(xs_tz[n].tz, tz) == 0)
return xs_tz[n].h_offset * 3600;
}
return 0;
}
#endif /* XS_IMPLEMENTATION */
#endif /* _XS_TIME_H */