#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>

#define TRUE 1

/*
 * This program creates a socket and then begins an infinite loop. Each time
 * through the loop it accepts a connection and prints out messages from it.
 * When the connection breaks, or a termination message comes through, the
 * program accepts a new connection.
 */

main()
{
     int sock, length; 
     struct sockaddr_in server; 
     int msgsock; 
     char buf[1024]; 
     int rval; 
     int i;

     /* Create socket */ 
     sock = socket(AF_INET, SOCK_STREAM, 0); 
     if (sock < 0) { 
          perror("opening stream socket"); 
          exit(1); 
     } 

     /* Name socket using wildcards */ 
     server.sin_family = AF_INET; 
     server.sin_addr.s_addr = INADDR_ANY; 
     server.sin_port = 0; 
     if (bind(sock, &server, sizeof(server))) { 
          perror("binding stream socket"); 
          exit(1); 
     } 

     /* Find out assigned port number and print it out */ 
     length = sizeof(server); 
     if (getsockname(sock, &server, &length)) { 
          perror("getting socket name"); 
          exit(1); 
     } 
     printf("Socket has port #%d\n", ntohs(server.sin_port));

     /* Start accepting connections */ 
     listen(sock, 5); 
     do { 
          msgsock = accept(sock, 0, 0); 
          if (msgsock == -1) 
               perror("accept");
          else do {
               bzero(buf, sizeof(buf));
               if ((rval = read(msgsock, buf, 1024)) < 0)
                    perror("reading stream message");
               i = 0;
               if (rval == 0)
                    printf("Ending connection\n");
               else
                    printf("-->%s\n", buf);
          } while (rval != 0);
          close(msgsock);
     } while (TRUE);

     /*
      * Since this program has an infinite loop, the socket "sock" is
      * never explicitly closed. However, all sockets will be closed
      * automatically when a process is killed or terminates normally.
      */
}