68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
/*
|
|
** 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 "4711" // 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 bind 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;
|
|
}
|