// fritz very simple portscan in 24 lines :) 
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
main(int argn, char **argv)
{
 struct sockaddr_in address;
 int porta, sock, z;
 if (argn!=4) 
     {printf("\nUsage: %s <ip> <porta_iniziale> <porta_finale>\n",argv[0]);
      exit(0);}
 for (porta=atoi(argv[2]); porta<=atoi(argv[3]); porta++)
      {
      if ((sock=socket(AF_INET, SOCK_STREAM, 0))==-1) perror("Socket:");
      else { 
          address.sin_family=AF_INET;
	  address.sin_addr.s_addr=inet_addr(argv[1]);
	  address.sin_port=htons(porta);	
	  if (z=connect(sock,(struct sockaddr*) &address, sizeof(address))==0) 
	     printf ("\nfound port %d open!", porta); 
	   }
     close (sock);
     }
}