sys/src/cmd/upas/fs/strtotm.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 static char*
   5 skiptext(char *q)
   6 {
   7         while(*q != '\0' && *q != ' ' && *q != '\t' && *q != '\r' && *q != '\n')
   8                 q++;
   9         return q;
  10 }
  11
  12 static char*
  13 skipwhite(char *q)
  14 {
  15         while(*q == ' ' || *q == '\t' || *q == '\r' || *q == '\n')
  16                 q++;
  17         return q;
  18 }
  19
  20 static char* months[] = {
  21         "jan", "feb", "mar", "apr",
  22         "may", "jun", "jul", "aug",
  23         "sep", "oct", "nov", "dec"
  24 };
  25
  26 int
  27 strtotm(char *p, Tm *t)
  28 {
  29         char *q, *r;
  30         int j;
  31         Tm tm;
  32         int delta;
  33
  34         delta = 0;
  35         memset(&tm, 0, sizeof(tm));
  36         tm.mon = -1;
  37         tm.hour = -1;
  38         tm.min = -1;
  39         tm.year = -1;
  40         tm.mday = -1;
  41         memcpy(tm.zone, "GMT", 3);
  42         for(p = skipwhite(p); *p; p = skipwhite(q)){
  43                 q = skiptext(p);
  44
  45                 /* look for time in hh:mm[:ss] */
  46                 if(r = memchr(p, ':', q - p)){
  47                         tm.hour = strtol(p, 0, 10);
  48                         tm.min = strtol(r + 1, 0, 10);
  49                         if(r = memchr(r + 1, ':', q - (r + 1)))
  50                                 tm.sec = strtol(r + 1, 0, 10);
  51                         else
  52                                 tm.sec = 0;
  53                         continue;
  54                 }
  55
  56                 /* look for month */
  57                 for(j = 0; j < 12; j++)
  58                         if(cistrncmp(p, months[j], 3) == 0){
  59                                 tm.mon = j;
  60                                 break;
  61                         }
  62                 if(j != 12)
  63                         continue;
  64
  65                 /* look for time zone [A-Z][A-Z]T */
  66                 if(q - p == 3)
  67                 if(p[0] >= 'A' && p[0] <= 'Z')
  68                 if(p[1] >= 'A' && p[1] <= 'Z')
  69                 if(p[2] == 'T'){
  70                         strecpy(tm.zone, tm.zone + 4, p);
  71                         continue;
  72                 }
  73
  74                 if(p[0] == '+'||p[0] == '-')
  75                 if(q - p == 5 && strspn(p + 1, "0123456789") == 4){
  76                         delta = (((p[1] - '0')*10 + p[2] - '0')*60 + (p[3] - '0')*10 + p[4] - '0')*60;
  77                         if(p[0] == '-')
  78                                 delta = -delta;
  79                         continue;
  80                 }
  81                 if(strspn(p, "0123456789") == q - p){
  82                         j = strtol(p, nil, 10);
  83                         if(j >= 1 && j <= 31)
  84                                 tm.mday = j;
  85                         if(j >= 1900)
  86                                 tm.year = j - 1900;
  87                         continue;
  88                 }
  89                 //eprint("strtotm: garbage %.*s\n", utfnlen(p, q - p), p);
  90         }
  91         if(tm.mon < 0 || tm.year < 0
  92         || tm.hour < 0 || tm.min < 0
  93         || tm.mday < 0)
  94                 return -1;
  95
  96         *t = *localtime(tm2sec(&tm) - delta);
  97         return 0;
  98 }