#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <time.h>
#include <string.h>

int
main (int argc, char **argv)
{
 int sd, result, server_port;
 struct hostent *he;
 struct sockaddr_in servaddr;

 printf ("Test TCP/IP port scanner:\n");

 if (argc != 2)
   {
     printf ("Usage: %s host\n", argv[0]);
     exit (1);
   }

 if ((he = gethostbyname (argv[1])) == NULL)
   {
     perror ("gethostbyname()");
     exit (1);
   }

 printf ("Scanning %s\n", argv[1]);

 for (server_port = 0; server_port < 65536; server_port++)
   {
     if ((sd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
    {
      perror ("socket()");
      exit (1);
    }

     bzero (&servaddr, sizeof servaddr);
     servaddr.sin_family = AF_INET;
     servaddr.sin_port = htons (server_port);
     servaddr.sin_addr = *((struct in_addr *) he->h_addr);

     result = connect (sd, (struct sockaddr *) &servaddr, sizeof servaddr);

     if (result != -1)
    {
      printf ("open port:  %d\n",server_port);
    }
     close (sd);
   }
 return result;
}