/*
 * From the BSD 4.4 IPC tutorial.
 * Figure 6a - Reading Internet domain datagrams.
 */

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

main()
{
  int sock, length;
  struct sockaddr_in name;
  char buf[1024], hostname[512];

  sock = socket(AF_INET, SOCK_DGRAM, 0);
  if(sock < 0){
    perror("opening datagram socket");
    exit(1);
  }

  name.sin_family = AF_INET;
  name.sin_addr.s_addr = INADDR_ANY;
  name.sin_port = 0;
  if(bind(sock, &name, sizeof(name)) < 0){
    perror("bind");
    exit(1);
  }

  length = sizeof(name);
  if(getsockname(sock, &name, &length) < 0){
    perror("getting socket name");
    exit(1);
  }

  gethostname(hostname, sizeof(hostname));
  printf("host %s port %d\n", hostname, ntohs(name.sin_port));
  
  if(read(sock, buf, 1024) < 0)
    perror("receiving datagram packet");
  printf("-->%s\n", buf);
  close(sock);

  exit(0);
}