nsz Git - musl/blob - src/time/strptime.c

   1 #include <stdlib.h>
   2 #include <langinfo.h>
   3 #include <time.h>
   4 #include <ctype.h>
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <strings.h>
   8
   9 char *strptime(const char *restrict s, const char *restrict f, struct tm *restrict tm)
  10 {
  11         int i, w, neg, adj, min, range, *dest, dummy;
  12         const char *ex;
  13         size_t len;
  14         int want_century = 0, century = 0;
  15         while (*f) {
  16                 if (*f != '%') {
  17                         if (isspace(*f)) for (; *s && isspace(*s); s++);
  18                         else if (*s != *f) return 0;
  19                         else s++;
  20                         f++;
  21                         continue;
  22                 }
  23                 f++;
  24                 if (*f == '+') f++;
  25                 if (isdigit(*f)) {
  26                         char *new_f;
  27                         w=strtoul(f, &new_f, 10);
  28                         f = new_f;
  29                 } else {
  30                         w=-1;
  31                 }
  32                 adj=0;
  33                 switch (*f++) {
  34                 case 'a': case 'A':
  35                         dest = &tm->tm_wday;
  36                         min = ABDAY_1;
  37                         range = 7;
  38                         goto symbolic_range;
  39                 case 'b': case 'B': case 'h':
  40                         dest = &tm->tm_mon;
  41                         min = ABMON_1;
  42                         range = 12;
  43                         goto symbolic_range;
  44                 case 'c':
  45                         s = strptime(s, nl_langinfo(D_T_FMT), tm);
  46                         if (!s) return 0;
  47                         break;
  48                 case 'C':
  49                         dest = &century;
  50                         if (w<0) w=2;
  51                         want_century |= 2;
  52                         goto numeric_digits;
  53                 case 'd': case 'e':
  54                         dest = &tm->tm_mday;
  55                         min = 1;
  56                         range = 31;
  57                         goto numeric_range;
  58                 case 'D':
  59                         s = strptime(s, "%m/%d/%y", tm);
  60                         if (!s) return 0;
  61                         break;
  62                 case 'H':
  63                         dest = &tm->tm_hour;
  64                         min = 0;
  65                         range = 24;
  66                         goto numeric_range;
  67                 case 'I':
  68                         dest = &tm->tm_hour;
  69                         min = 1;
  70                         range = 12;
  71                         goto numeric_range;
  72                 case 'j':
  73                         dest = &tm->tm_yday;
  74                         min = 1;
  75                         range = 366;
  76                         goto numeric_range;
  77                 case 'm':
  78                         dest = &tm->tm_mon;
  79                         min = 1;
  80                         range = 12;
  81                         adj = 1;
  82                         goto numeric_range;
  83                 case 'M':
  84                         dest = &tm->tm_min;
  85                         min = 0;
  86                         range = 60;
  87                         goto numeric_range;
  88                 case 'n': case 't':
  89                         for (; *s && isspace(*s); s++);
  90                         break;
  91                 case 'p':
  92                         ex = nl_langinfo(AM_STR);
  93                         len = strlen(ex);
  94                         if (!strncasecmp(s, ex, len)) {
  95                                 tm->tm_hour %= 12;
  96                                 break;
  97                         }
  98                         ex = nl_langinfo(PM_STR);
  99                         len = strlen(ex);
 100                         if (!strncasecmp(s, ex, len)) {
 101                                 tm->tm_hour %= 12;
 102                                 tm->tm_hour += 12;
 103                                 break;
 104                         }
 105                         return 0;
 106                 case 'r':
 107                         s = strptime(s, nl_langinfo(T_FMT_AMPM), tm);
 108                         if (!s) return 0;
 109                         break;
 110                 case 'R':
 111                         s = strptime(s, "%H:%M", tm);
 112                         if (!s) return 0;
 113                         break;
 114                 case 'S':
 115                         dest = &tm->tm_sec;
 116                         min = 0;
 117                         range = 61;
 118                         goto numeric_range;
 119                 case 'T':
 120                         s = strptime(s, "%H:%M:%S", tm);
 121                         if (!s) return 0;
 122                         break;
 123                 case 'U':
 124                 case 'W':
 125                         /* Throw away result, for now. (FIXME?) */
 126                         dest = &dummy;
 127                         min = 0;
 128                         range = 54;
 129                         goto numeric_range;
 130                 case 'w':
 131                         dest = &tm->tm_wday;
 132                         min = 0;
 133                         range = 7;
 134                         goto numeric_range;
 135                 case 'x':
 136                         s = strptime(s, nl_langinfo(D_FMT), tm);
 137                         if (!s) return 0;
 138                         break;
 139                 case 'X':
 140                         s = strptime(s, nl_langinfo(T_FMT), tm);
 141                         if (!s) return 0;
 142                         break;
 143                 case 'y':
 144                         dest = &tm->tm_year;
 145                         w = 2;
 146                         want_century |= 1;
 147                         goto numeric_digits;
 148                 case 'Y':
 149                         dest = &tm->tm_year;
 150                         if (w<0) w=4;
 151                         adj = 1900;
 152                         want_century = 0;
 153                         goto numeric_digits;
 154                 case '%':
 155                         if (*s++ != '%') return 0;
 156                         break;
 157                 default:
 158                         return 0;
 159                 numeric_range:
 160                         if (!isdigit(*s)) return 0;
 161                         *dest = 0;
 162                         for (i=1; i<=min+range && isdigit(*s); i*=10)
 163                                 *dest = *dest * 10 + *s++ - '0';
 164                         if (*dest - min >= (unsigned)range) return 0;
 165                         *dest -= adj;
 166                         switch((char *)dest - (char *)tm) {
 167                         case offsetof(struct tm, tm_yday):
 168                                 ;
 169                         }
 170                         goto update;
 171                 numeric_digits:
 172                         neg = 0;
 173                         if (*s == '+') s++;
 174                         else if (*s == '-') neg=1, s++;
 175                         if (!isdigit(*s)) return 0;
 176                         for (*dest=i=0; i<w && isdigit(*s); i++)
 177                                 *dest = *dest * 10 + *s++ - '0';
 178                         if (neg) *dest = -*dest;
 179                         *dest -= adj;
 180                         goto update;
 181                 symbolic_range:
 182                         for (i=2*range-1; i>=0; i--) {
 183                                 ex = nl_langinfo(min+i);
 184                                 len = strlen(ex);
 185                                 if (strncasecmp(s, ex, len)) continue;
 186                                 s += len;
 187                                 *dest = i % range;
 188                                 break;
 189                         }
 190                         if (i<0) return 0;
 191                         goto update;
 192                 update:
 193                         //FIXME
 194                         ;
 195                 }
 196         }
 197         if (want_century) {
 198                 if (want_century & 2) tm->tm_year += century * 100 - 1900;
 199                 else if (tm->tm_year <= 68) tm->tm_year += 100;
 200         }
 201         return (char *)s;
 202 }