/* client2.c -- request-reply demo
 Compilation on cs:
 gcc -Wall -o client2 client2.c -lnsl -lsocket -lresolv
 */

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

#define MAXDATASIZE 100 // max number of bytes we can get at once 

int main(int argc, char *argv[])
{
  int sockfd, numbytes, reqnum = 1;
  char buf[MAXDATASIZE], req[MAXDATASIZE];
  struct hostent *he;
  struct sockaddr_in their_addr; // connector's address information 
  int port = 5555;      // default port

  /* hostname as first parameter */
  if (argc < 2) {
	  fprintf(stderr,"usage: %s hostname [number] [port]\n", argv[0]);
	  exit(1);
  }

  if ((he=gethostbyname(argv[1])) == NULL) {  // get the host info 
	  perror("gethostbyname");
	  exit(1);
  }

  /* request as optional second parameter */
  if (argc > 2)
	  reqnum = atoi(argv[2]);

  /* port as optional third parameter */
  if (argc > 3)
	  port = atoi(argv[3]);

  /* get socket */
  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
	  perror("socket");
	  exit(1);
  }

  /* construct host address struct */
  their_addr.sin_family = AF_INET;    // host byte order 
  their_addr.sin_port = htons(port);  // short, network byte order 
  their_addr.sin_addr = *((struct in_addr *)he->h_addr);
  memset(&(their_addr.sin_zero), '\0', 8);  // zero the rest of the struct 

  /* connect */
  if (connect(sockfd, (struct sockaddr *)&their_addr, sizeof(struct sockaddr)) == -1) {
	  perror("connect");
	  exit(1);
  }

  /* construct and send request */
  sprintf(req, "%d\015\012", reqnum);

  if (send(sockfd, req, strlen(req), 0) == -1) {
	  perror("send");
	  exit(1);
  }


  /* receive until revc returns 0 (connection closed) (or -1 (error)) */

  printf("Receiving:\n");
  while ((numbytes = recv(sockfd, buf, MAXDATASIZE-1, 0))) {
	  if (numbytes == -1) {
		  perror("recv");
		  exit(1);
	  }
	  buf[numbytes] = '\0';	/* terminate string */
	  fputs(buf, stdout);
  }

  close(sockfd);

  return 0;
}