-#include <sys/types.h> /* predefined types */
+#include <stdlib.h> /* predefined types */
#include <unistd.h> /* include unix standard library */
#include <arpa/inet.h> /* IP addresses conversion utilities */
#include <sys/socket.h> /* socket library */
#include <stdio.h> /* include standard I/O library */
+#include <string.h> /* C strings library */
int main(int argc, char *argv[])
{