1  #include <string.h>
       2  
       3  int memcmp(const void *cs, const void *ct, size_t count)
       4  {
       5   const unsigned char *su1, *su2;
       6   int res = 0;
       7  
       8   for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
       9    if ((res = *su1 - *su2) != 0)
      10     break;
      11   return res;
      12  }