reactos/lib/sdk/crt/string/strpbrk.c

   1 /*
   2  * $Id$
   3  */
   4 #include <limits.h>
   5 #include <string.h>
   6
   7 #define BIT_SIZE (CHAR_BIT * sizeof(unsigned long) / sizeof(char))
   8
   9 char* strpbrk(const char *s1, const char *s2)
  10 {
  11     if (*s2 == 0)
  12     {
  13        return 0;
  14     }
  15     if (*(s2+1) == 0)
  16     {
  17        return strchr(s1, *s2);
  18     }
  19     else if (*(s2+2) == 0)
  20     {
  21        char *s3, *s4;
  22        s3 = strchr(s1, *s2);
  23        s4 = strchr(s1, *(s2+1));
  24        if (s3 == 0)
  25        {
  26           return s4;
  27        }
  28        else if (s4 == 0)
  29        {
  30           return s3;
  31        }
  32        return s3 < s4 ? s3 : s4;
  33     }
  34     else
  35     {
  36        unsigned long char_map[(1 << CHAR_BIT) / BIT_SIZE] = {0, };
  37        const unsigned char* str = (const unsigned char*)s1;
  38        while (*s2)
  39        {
  40           char_map[*(const unsigned char*)s2 / BIT_SIZE] |= (1 << (*(const unsigned char*)s2 % BIT_SIZE));
  41           s2++;
  42        }
  43        while (*str)
  44        {
  45           if (char_map[*str / BIT_SIZE] & (1 << (*str % BIT_SIZE)))
  46           {
  47              return (char*)((size_t)str);
  48           }
  49           str++;
  50        }
  51     }
  52     return 0;
  53 }
  54