blob: cc53d5369ca717900ef5816ed7bdc400d149dc6b [file] [log] [blame] [edit]
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <langinfo.h>
#include <locale.h>
#include <time.h>
#include <limits.h>
#include "locale_impl.h"
#include "time_impl.h"
static int is_leap(int y)
{
/* Avoid overflow */
if (y>INT_MAX-1900) y -= 2000;
y += 1900;
return !(y%4) && ((y%100) || !(y%400));
}
static int week_num(const struct tm *tm)
{
int val = (tm->tm_yday + 7U - (tm->tm_wday+6U)%7) / 7;
/* If 1 Jan is just 1-3 days past Monday,
* the previous week is also in this year. */
if ((tm->tm_wday + 371U - tm->tm_yday - 2) % 7 <= 2)
val++;
if (!val) {
val = 52;
/* If 31 December of prev year a Thursday,
* or Friday of a leap year, then the
* prev year has 53 weeks. */
int dec31 = (tm->tm_wday + 7U - tm->tm_yday - 1) % 7;
if (dec31 == 4 || (dec31 == 5 && is_leap(tm->tm_year%400-1)))
val++;
} else if (val == 53) {
/* If 1 January is not a Thursday, and not
* a Wednesday of a leap year, then this
* year has only 52 weeks. */
int jan1 = (tm->tm_wday + 371U - tm->tm_yday) % 7;
if (jan1 != 4 && (jan1 != 3 || !is_leap(tm->tm_year)))
val = 1;
}
return val;
}
const char *__strftime_fmt_1(char (*s)[100], size_t *l, int f, const struct tm *tm, locale_t loc, int pad)
{
nl_item item;
long long val;
const char *fmt = "-";
int width = 2, def_pad = '0';
switch (f) {
case 'a':
if (tm->tm_wday > 6U) goto string;
item = ABDAY_1 + tm->tm_wday;
goto nl_strcat;
case 'A':
if (tm->tm_wday > 6U) goto string;
item = DAY_1 + tm->tm_wday;
goto nl_strcat;
case 'h':
case 'b':
if (tm->tm_mon > 11U) goto string;
item = ABMON_1 + tm->tm_mon;
goto nl_strcat;
case 'B':
if (tm->tm_mon > 11U) goto string;
item = MON_1 + tm->tm_mon;
goto nl_strcat;
case 'c':
item = D_T_FMT;
goto nl_strftime;
case 'C':
val = (1900LL+tm->tm_year) / 100;
goto number;
case 'e':
def_pad = '_';
case 'd':
val = tm->tm_mday;
goto number;
case 'D':
fmt = "%m/%d/%y";
goto recu_strftime;
case 'F':
fmt = "%Y-%m-%d";
goto recu_strftime;
case 'g':
case 'G':
val = tm->tm_year + 1900LL;
if (tm->tm_yday < 3 && week_num(tm) != 1) val--;
else if (tm->tm_yday > 360 && week_num(tm) == 1) val++;
if (f=='g') val %= 100;
else width = 4;
goto number;
case 'H':
val = tm->tm_hour;
goto number;
case 'I':
val = tm->tm_hour;
if (!val) val = 12;
else if (val > 12) val -= 12;
goto number;
case 'j':
val = tm->tm_yday+1;
width = 3;
goto number;
case 'm':
val = tm->tm_mon+1;
goto number;
case 'M':
val = tm->tm_min;
goto number;
case 'n':
*l = 1;
return "\n";
case 'p':
item = tm->tm_hour >= 12 ? PM_STR : AM_STR;
goto nl_strcat;
case 'r':
item = T_FMT_AMPM;
goto nl_strftime;
case 'R':
fmt = "%H:%M";
goto recu_strftime;
case 's':
val = __tm_to_secs(tm) - tm->__tm_gmtoff;
width = 1;
goto number;
case 'S':
val = tm->tm_sec;
goto number;
case 't':
*l = 1;
return "\t";
case 'T':
fmt = "%H:%M:%S";
goto recu_strftime;
case 'u':
val = tm->tm_wday ? tm->tm_wday : 7;
width = 1;
goto number;
case 'U':
val = (tm->tm_yday + 7U - tm->tm_wday) / 7;
goto number;
case 'W':
val = (tm->tm_yday + 7U - (tm->tm_wday+6U)%7) / 7;
goto number;
case 'V':
val = week_num(tm);
goto number;
case 'w':
val = tm->tm_wday;
width = 1;
goto number;
case 'x':
item = D_FMT;
goto nl_strftime;
case 'X':
item = T_FMT;
goto nl_strftime;
case 'y':
val = (tm->tm_year + 1900LL) % 100;
if (val < 0) val = -val;
goto number;
case 'Y':
val = tm->tm_year + 1900LL;
if (val >= 10000) {
*l = snprintf(*s, sizeof *s, "+%lld", val);
return *s;
}
width = 4;
goto number;
case 'z':
if (tm->tm_isdst < 0) {
*l = 0;
return "";
}
*l = snprintf(*s, sizeof *s, "%+.4ld",
tm->__tm_gmtoff/3600*100 + tm->__tm_gmtoff%3600/60);
return *s;
case 'Z':
if (tm->tm_isdst < 0) {
*l = 0;
return "";
}
fmt = __tm_to_tzname(tm);
goto string;
case '%':
*l = 1;
return "%";
default:
return 0;
}
number:
switch (pad ? pad : def_pad) {
case '-': *l = snprintf(*s, sizeof *s, "%lld", val); break;
case '_': *l = snprintf(*s, sizeof *s, "%*lld", width, val); break;
case '0':
default: *l = snprintf(*s, sizeof *s, "%0*lld", width, val); break;
}
return *s;
nl_strcat:
fmt = __nl_langinfo_l(item, loc);
string:
*l = strlen(fmt);
return fmt;
nl_strftime:
fmt = __nl_langinfo_l(item, loc);
recu_strftime:
*l = __strftime_l(*s, sizeof *s, fmt, tm, loc);
if (!*l) return 0;
return *s;
}
size_t __strftime_l(char *restrict s, size_t n, const char *restrict f, const struct tm *restrict tm, locale_t loc)
{
size_t l, k;
char buf[100];
char *p;
const char *t;
int pad, plus;
unsigned long width;
for (l=0; l<n; f++) {
if (!*f) {
s[l] = 0;
return l;
}
if (*f != '%') {
s[l++] = *f;
continue;
}
f++;
pad = 0;
if (*f == '-' || *f == '_' || *f == '0') pad = *f++;
if ((plus = (*f == '+'))) f++;
width = strtoul(f, &p, 10);
if (*p == 'C' || *p == 'F' || *p == 'G' || *p == 'Y') {
if (!width && p!=f) width = 1;
} else {
width = 0;
}
f = p;
if (*f == 'E' || *f == 'O') f++;
t = __strftime_fmt_1(&buf, &k, *f, tm, loc, pad);
if (!t) break;
if (width) {
/* Trim off any sign and leading zeros, then
* count remaining digits to determine behavior
* for the + flag. */
if (*t=='+' || *t=='-') t++, k--;
for (; *t=='0' && t[1]-'0'<10U; t++, k--);
if (width < k) width = k;
size_t d;
for (d=0; t[d]-'0'<10U; d++);
if (tm->tm_year < -1900) {
s[l++] = '-';
width--;
} else if (plus && d+(width-k) >= (*p=='C'?3:5)) {
s[l++] = '+';
width--;
}
for (; width > k && l < n; width--)
s[l++] = '0';
}
if (k > n-l) k = n-l;
memcpy(s+l, t, k);
l += k;
}
if (n) {
if (l==n) l=n-1;
s[l] = 0;
}
return 0;
}
size_t strftime(char *restrict s, size_t n, const char *restrict f, const struct tm *restrict tm)
{
return __strftime_l(s, n, f, tm, CURRENT_LOCALE);
}
weak_alias(__strftime_l, strftime_l);