#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void *memmem(const void *buf, const void *pattern, size_t buflen, size_t len)
{
    char *bf = (char *)buf, *pt = (char *)pattern, *p = bf;

    while (len <= (buflen - (p - bf)))
    {
          if (NULL != (p = memchr(p, (int)(*pt), buflen - (p - bf))))
          {
               if (!memcmp(p, pattern, len))
                        return p;
               else  ++p;
          }
          else  break;
    }
    return NULL;
}

void main()
{
   char *ptr1 = "kjkdkjafk;fdakjk;ljfd;lasjdfk;lasjdfk;lasjdk;asjI love her\0ksdljkfd;jsd";
   char *ptr2 = "I love";
   char *pstr;

   pstr = memmem(ptr1, ptr2, strlen(ptr1), strlen(ptr2));
   printf("%s\n", pstr);
}