/*
** talker.c -- a datagram "client" demo
*/

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

#define SERVERPORT 3490    /* the port users will be connecting to */
#define MAXBUFLEN 128

int main(int argc, char *argv[])
{
    char buf[MAXBUFLEN];
    int sockfd, sin_size;
    struct sockaddr_in their_addr; /* connector's address information */
    struct hostent *he;
    int numbytes;

    if (argc != 2) {
        fprintf(stderr,"usage: client_udptcp hostname \n");
        exit(1);
    }

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

    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    their_addr.sin_family = AF_INET;         /* host byte order */
    their_addr.sin_port = htons(SERVERPORT);     /* short, network byte order */
    their_addr.sin_addr = *((struct in_addr *)he->h_addr);
    bzero(&(their_addr.sin_zero), 8);        /* zero the rest of the struct */
    sin_size = sizeof(struct sockaddr);

    if ((numbytes= sendto(sockfd,buf,0,0,(struct sockaddr *)&their_addr,
                         sizeof(struct sockaddr_in))) == -1) {
        perror("sendto");
        exit(1);
    }

    if ((numbytes=recvfrom(sockfd,buf, MAXBUFLEN,0,(struct sockaddr *)&their_addr,
                         &sin_size)) == -1) {
        perror("recvfrom");
        exit(1);
    }
    buf[numbytes]=0;
    printf("received: %sfrom: %s\n",buf,inet_ntoa(their_addr.sin_addr));

    close(sockfd);

    return 0;
}