compat/strftime.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <time.h>
   4 #include "strftime.h"
   5
   6 static const char *monthAbbr[]={
   7         "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};
   8 size_t strftime(char *s,size_t max, const char *format,
   9                 const struct tm *tm) {
  10         size_t i=0,j=0;
  11         while(j<max && format[i]) {
  12                 if (format[i]!='%') {
  13                         s[j]=format[i];
  14                         i++;j++;
  15                 } else {
  16                         i++;
  17                         switch (format[i]) {
  18                                 case '%': s[j++]='%';break;
  19                                 case 'm': if ((j+2) >=max) return 0;
  20                                                   j+=sprintf(s+j,"%02d",tm->tm_mon+1);
  21                                                   break;
  22                                 case 'd': if ((j+2) >=max) return 0;
  23                                                   j+=sprintf(s+j,"%02d",tm->tm_mday);
  24                                                   break;
  25                                 case 'y': if ((j+2) >=max) return 0;
  26                                                   j+=sprintf(s+j,"%02d",tm->tm_year%100);
  27                                                   break;
  28                                 case 'Y': if ((j+4) >=max) return 0;
  29                                                   j+=sprintf(s+j,"%d",tm->tm_year+1900);
  30                                                   break;
  31                                 case 'b': if ((j+3)>=max) return 0;
  32                                                          strcpy(s+j,monthAbbr[tm->tm_mon]);
  33                                                          j+=3;
  34                                                   break;
  35                                 case 'l': if ((j+2) >= max) return 0;
  36                                                           { int hour = tm->tm_hour;
  37                                                                   if (hour>12) hour -=12;
  38                                                                   if (hour == 0) hour = 12;
  39                                                                   j+=sprintf(s+j,"%2d",hour);
  40                                                                   break;
  41                                                           }
  42                                 case 'p':  if ((j+2) >= max) return 0;
  43                                                   if (tm->tm_hour >11) {
  44                                                           strcpy(s+j,"PM");
  45                                                   } else {
  46                                                           strcpy(s+j,"AM");
  47                                                   }
  48                                                    j+=2;
  49                                                   break;
  50                                 case 'H':  if ((j+2) >= max) return 0;
  51                                                    j+=sprintf(s+j,"%02d",tm->tm_hour);
  52                                                         break;
  53                                 case 'M':if ((j+2) >= max) return 0;
  54                                                    j+=sprintf(s+j,"%02d",tm->tm_min);
  55                                                         break;
  56                                 case 'S':if ((j+2) >= max) return 0;
  57                                                    j+=sprintf(s+j,"%02d",tm->tm_sec);
  58                                                         break;
  59                                 default:
  60                                                         ;
  61                         }
  62                         i++;
  63                 }
  64         }
  65         if (j>=max) return 0;
  66         else {
  67                 s[j]=0;
  68                 return j;
  69         }
  70 }