| #include <stdio.h> |
| #include <stdlib.h> |
| #include <langinfo.h> |
| #include <locale.h> |
| #include <time.h> |
| #include <limits.h> |
| #include "libc.h" |
| |
| // FIXME: integer overflows |
| |
| const char *__nl_langinfo_l(nl_item, locale_t); |
| |
| 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 + 7 - (tm->tm_wday+6)%7) / 7; |
| /* If 1 Jan is just 1-3 days past Monday, |
| * the previous week is also in this year. */ |
| if ((tm->tm_wday - tm->tm_yday - 2 + 371) % 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 - tm->tm_yday - 1 + 7) % 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 - tm->tm_yday + 371) % 7; |
| if (jan1 != 4 && (jan1 != 3 || !is_leap(tm->tm_year))) |
| val = 1; |
| } |
| return val; |
| } |
| |
| size_t __strftime_l(char *restrict, size_t, const char *restrict, const struct tm *restrict, locale_t); |
| |
| int __strftime_fmt_1(char *s, size_t n, int f, const struct tm *tm, locale_t loc) |
| { |
| nl_item item; |
| int val; |
| const char *fmt; |
| size_t l; |
| |
| if (n<2) return 0; |
| |
| switch (f) { |
| case 'a': |
| item = ABDAY_1 + tm->tm_wday; |
| goto nl_strcat; |
| case 'A': |
| item = DAY_1 + tm->tm_wday; |
| goto nl_strcat; |
| case 'h': |
| case 'b': |
| item = ABMON_1 + tm->tm_mon; |
| goto nl_strcat; |
| case 'B': |
| item = MON_1 + tm->tm_mon; |
| goto nl_strcat; |
| case 'c': |
| item = D_T_FMT; |
| goto nl_strftime; |
| case 'C': |
| val = (1900+tm->tm_year) / 100; |
| fmt = "%02d"; |
| goto number; |
| case 'd': |
| val = tm->tm_mday; |
| fmt = "%02d"; |
| goto number; |
| case 'D': |
| fmt = "%m/%d/%y"; |
| goto recu_strftime; |
| case 'e': |
| val = tm->tm_mday; |
| fmt = "%2d"; |
| goto number; |
| case 'F': |
| fmt = "%Y-%m-%d"; |
| goto recu_strftime; |
| case 'g': |
| case 'G': |
| fmt = "%04d"; |
| val = tm->tm_year + 1900; |
| if (tm->tm_yday < 3 && week_num(tm) != 1) val--; |
| else if (tm->tm_yday > 360 && week_num(tm) == 1) val++; |
| if (f=='g') { |
| fmt = "%02d"; |
| val %= 100; |
| } |
| goto number; |
| case 'H': |
| val = tm->tm_hour; |
| fmt = "%02d"; |
| goto number; |
| case 'I': |
| val = tm->tm_hour; |
| if (!val) val = 12; |
| else if (val > 12) val -= 12; |
| fmt = "%02d"; |
| goto number; |
| case 'j': |
| val = tm->tm_yday+1; |
| fmt = "%03d"; |
| goto number; |
| case 'm': |
| val = tm->tm_mon+1; |
| fmt = "%02d"; |
| goto number; |
| case 'M': |
| val = tm->tm_min; |
| fmt = "%02d"; |
| goto number; |
| case 'n': |
| s[0] = '\n'; |
| s[1] = 0; |
| return 1; |
| 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->tm_sec; |
| fmt = "%02d"; |
| goto number; |
| case 't': |
| s[0] = '\t'; |
| s[1] = 0; |
| return 1; |
| case 'T': |
| fmt = "%H:%M:%S"; |
| goto recu_strftime; |
| case 'u': |
| val = tm->tm_wday ? tm->tm_wday : 7; |
| fmt = "%d"; |
| goto number; |
| case 'U': |
| val = (tm->tm_yday + 7 - tm->tm_wday) / 7; |
| fmt = "%02d"; |
| goto number; |
| case 'W': |
| val = (tm->tm_yday + 7 - (tm->tm_wday+6)%7) / 7; |
| fmt = "%02d"; |
| goto number; |
| case 'V': |
| val = week_num(tm); |
| fmt = "%02d"; |
| goto number; |
| case 'w': |
| val = tm->tm_wday; |
| fmt = "%d"; |
| goto number; |
| case 'x': |
| item = D_FMT; |
| goto nl_strftime; |
| case 'X': |
| item = T_FMT; |
| goto nl_strftime; |
| case 'y': |
| val = tm->tm_year % 100; |
| fmt = "%02d"; |
| goto number; |
| case 'Y': |
| val = tm->tm_year + 1900; |
| fmt = "%04d"; |
| goto number; |
| case 'z': |
| val = -tm->__tm_gmtoff; |
| return snprintf(s, n, "%+.2d%.2d", val/3600, abs(val%3600)/60); |
| case 'Z': |
| return snprintf(s, n, "%s", tm->__tm_zone); |
| case '%': |
| s[0] = '%'; |
| s[1] = 0; |
| return 1; |
| default: |
| return 0; |
| } |
| number: |
| return snprintf(s, n, fmt, val); |
| nl_strcat: |
| return snprintf(s, n, "%s", __nl_langinfo_l(item, loc)); |
| nl_strftime: |
| fmt = __nl_langinfo_l(item, loc); |
| recu_strftime: |
| return __strftime_l(s, n, fmt, tm, loc); |
| } |
| |
| 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; |
| for (l=0; *f && l<n; f++) { |
| if (*f != '%') { |
| s[l++] = *f; |
| continue; |
| } |
| f++; |
| if (*f == 'E' || *f == 'O') f++; |
| k = __strftime_fmt_1(s+l, n-l, *f, tm, loc); |
| if (!k) return 0; |
| l += k; |
| } |
| if (l >= n) return 0; |
| s[l] = 0; |
| return l; |
| } |
| |
| 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, 0); |
| } |
| |
| weak_alias(__strftime_l, strftime_l); |