text: /*
  ** talker.c -- a datagram "client" demo
  */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <errno.h>
  #include <string.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <netdb.h>
  
  #define SERVERPORT "4950"	// the port users will be connecting to
  
  int main(int argc, char *argv[])
  {
  	int sockfd;
  	struct addrinfo hints, *servinfo, *p;
  	int rv;
  	int numbytes;
  
  	if (argc != 3) {
  		fprintf(stderr,"usage: talker hostname message\n");
  		exit(1);
  	}
  
  	memset(&hints, 0, sizeof hints);
  	hints.ai_family = AF_UNSPEC;
  	hints.ai_socktype = SOCK_DGRAM;
  
  	if ((rv = getaddrinfo(argv[1], SERVERPORT, &hints, &servinfo)) != 0) {
  		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
  		return 1;
  	}
  
  	// loop through all the results and make a socket
  	for(p = servinfo; p != NULL; p = p->ai_next) {
  		if ((sockfd = socket(p->ai_family, p->ai_socktype,
  				p->ai_protocol)) == -1) {
  			perror("talker: socket");
  			continue;
  		}
  
  		break;
  	}
  
  	if (p == NULL) {
  		fprintf(stderr, "talker: failed to create socket\n");
  		return 2;
  	}
  
  	if ((numbytes = sendto(sockfd, argv[2], strlen(argv[2]), 0,
  			 p->ai_addr, p->ai_addrlen)) == -1) {
  		perror("talker: sendto");
  		exit(1);
  	}
  
  	freeaddrinfo(servinfo);
  
  	printf("talker: sent %d bytes to %s\n", numbytes, argv[1]);
  	close(sockfd);
  
  	return 0;
  }
  