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