hex_dump

void hex_dump(void *addr, int len)
{

   printf("length of hexdump = %d", len);
   int            i;
   unsigned char  buff[17];
   unsigned char *pc = (unsigned char *)addr;

   // Process every byte in the data.
   for (i = 0; i < len; i++)
   {
      // Multiple of 16 means new line (with line offset).

      if ((i % 16) == 0)
      {
         // Just don't print ASCII for the zeroth line.
         if (i != 0)
            printf(" %s\n", buff);

         // Output the offset.
         printf(" %04x ", i);
      }

      // Now the hex code for the specific character.
      printf(" %02x", pc[i]);

      // And store a printable ASCII character for later.
      if ((pc[i] < 0x20) || (pc[i] > 0x7e))
         buff[i % 16] = '.';
      else
         buff[i % 16] = pc[i];
      buff[(i % 16) + 1] = '\0';
   }

   // Pad out last line if not exactly 16 characters.
   while ((i % 16) != 0)
   {
      printf(" ");
      i++;
   }

   // And print the final ASCII bit.
   printf(" %s\n", buff);
}

// Now the hex code for the specific character.
printf (" %02x", pc[i]);

// And store a printable ASCII character for later.
if ((pc[i] < 0x20) || (pc[i] > 0x7e))
buff[i % 16] = '.';
else
buff[i % 16] = pc[i];
buff[(i % 16) + 1] = '\0';
}

// Pad out last line if not exactly 16 characters.
while ((i % 16) != 0) {
printf (" ");
i++;
}

// And print the final ASCII bit.
printf (" %s\n", buff);
}