TCP/IP socket programming in C（二）

// get_ipaddr.c
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>

#include <sys/socket.h>
#include <netdb.h>

int main(int argc, char *argv[])
{
char *hostname = "www.baidu.com";
char ip[100];
struct hostent *he;
struct in_addr **addr_list;
int i;

if ((he = gethostbyname(hostname)) == NULL) {
// gethostbyname failed
herror("gethostbyname");
return 1;
}

// Cast the h_addr_list to in_addr, since h_addr_list also has the
// ip address in long format only
addr_list = (struct in_addr **)he->h_addr_list;

for (i = 0; addr_list[i] != NULL; i++) {
// Return the first one
strcpy(ip, inet_ntoa(*addr_list[i]));
}

printf("%s resolved to : %s\n", hostname, ip);
return 0;
}