test_getsockname.c [plain text]
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include "autoconf.h"
int
main(argc, argv)
int argc;
char *argv[];
{
int sock;
GETSOCKNAME_ARG3_TYPE i;
struct hostent *host;
struct sockaddr_in s_sock;
struct sockaddr_in c_sock;
char *hostname;
if (argc == 2) {
hostname = argv[1];
} else {
fprintf(stderr, "Usage: %s hostname\n", argv[0]);
exit(1);
}
if ((host = gethostbyname(hostname)) == (struct hostent *) 0) {
fprintf(stderr, "%s: unknown host\n", hostname);
exit(1);
}
(void) memset((char *)&s_sock, 0, sizeof(s_sock));
memcpy((char *)&s_sock.sin_addr, host->h_addr, sizeof(s_sock.sin_addr));
#ifdef DEBUG
printf("s_sock.sin_addr is %s\n", inet_ntoa(s_sock.sin_addr));
#endif
s_sock.sin_family = AF_INET;
s_sock.sin_port = htons(5555);
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("socket");
exit(1);
}
memset((char *)&c_sock, 0, sizeof(c_sock));
c_sock.sin_family = AF_INET;
if (bind(sock, (struct sockaddr *)&c_sock, sizeof(c_sock)) < 0) {
perror("bind");
exit(1);
}
if (connect(sock, (struct sockaddr *)&s_sock, sizeof(s_sock)) == -1) {
perror("connect");
exit(1);
}
memset((char *) &c_sock, 0, sizeof(c_sock));
i = sizeof(c_sock);
if (getsockname(sock, (struct sockaddr *)&c_sock, &i) < 0) {
perror("getsockname");
exit(1);
}
printf("My interface address is: %s\n", inet_ntoa(c_sock.sin_addr));
exit(0);
}