/* 
 * Example of client using UDP protocol.
 */

#include "inet.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc, char *argv[])
{
   int                sockfd;
   struct sockaddr_in serv_addr, cli_addr;
   struct hostent *hp;
   void dg_cli(FILE *, int, struct sockaddr *, int );

   if (argc != 2)
   {
      cerr << "usage : " << argv[0] << " remote_host " << endl;
      exit(1);
   }

   /* 
    * Get server's information
    */

   hp = gethostbyname(argv[1]);
   bzero((char *)&serv_addr, sizeof(serv_addr));
   bcopy(hp->h_addr, (char *)&serv_addr.sin_addr, hp->h_length);
   serv_addr.sin_port = htons(SERV_UDP_PORT);
   serv_addr.sin_family = hp->h_addrtype;
//   strcpy(serv_addr.sin_zero,argv[1]);

   /* 
    * Open a UDP socket (an Internet datagram socket)
    */

   if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
       err_dump("client: can't open datagram socket");

   /* 
    * Bind any local address for us
    */
  
   bzero((char *)&cli_addr, sizeof(cli_addr));
   cli_addr.sin_family = AF_INET;
   cli_addr.sin_addr.s_addr = htonl(INADDR_ANY);
/* port 0 allows the system to assign any available port */
   cli_addr.sin_port = htons(0);

/*
   cli_addr.sin_port = htons(3000);
*/

   if (bind(sockfd, (struct sockaddr *)&cli_addr, sizeof(cli_addr)) < 0)
      err_dump("client: can't bind local address");

   dg_cli(stdin, sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));

   close(sockfd);

   return 0;
}

/*
 * Read the contents of the FILE *fp, write each line to the datagram
 * socket, then read a line back from the datagram socket and write it to the
 * standard output.
 *
 */

#define MAXLINE 50000

void dg_cli(FILE *fp, int sockfd, struct sockaddr *pserv_addr, int servlen)
{
  int n;
  int maxservlen;
  char sendline[MAXLINE], recvline[MAXLINE+1];
  int fd;

  fd = creat("new.dat", 0644);

//  while (fgets(sendline,MAXLINE,fp) != NULL)
  while ((n = read(0, sendline, MAXLINE)) > 0)
  {
//    n = strlen(sendline);
    if (sendto(sockfd, sendline, n, 0, pserv_addr, servlen) != n)
       err_dump("dg_cli: sendto error on socket");

    /* 
     * Now read a message from the socket and write to 
     * standard output.
     */

    maxservlen = servlen;
    n = recvfrom(sockfd, recvline, MAXLINE, 0,
                pserv_addr, (socklen_t*)&maxservlen);


    if (n < 0)
       err_dump("dg_cli: recvfrom error");
    recvline[n] = 0;      /* null terminate */
    printf("%d === %s\n bytes received.", n, recvline);
    write(fd, recvline, n);

//    fputs(recvline,stdout);
  }

  close(fd);

  if (ferror(fp))
     err_dump("dg_cli: error reading file");
}