/@Abstract getHostInformation
*/

include <stdio.h>
include <stdlib.h>
include <netdb.h>
include <arpa/inet.h>
define NET_ADDR_STR_LEN 16     //16個字節，用于存放點分十進制IP地址的字符串長度
int main(int argc,char *argv)
{
    struct hostent host;   //存放主機信息
    char addr_p[NET_ADDR_STR_LEN]; //用于存放點分十進制IP地址的字符串
    int i;
    if((host = gethostent()) == NULL)
    {
        perror("fail to get host's information\n");
        exit(1);
    }
    printf("hostName: %s\n" , host->h_name);
    for(i = 0 ; host->h_aliases[i] != NULL;i++)
    {
        printf("%s\n" , host->h_aliases[i]);     //主機別名列表，可以又很多，以二維數組形式存儲   h_aliases[0] 為主機IP
    }
    if(host->h_addrtype == AF_INET)      //判斷IP類型是否是ipv4
    {
        printf("at_inet\n");
    }
    else
    {
        printf("unix_inet\n");
    }
    printf("len%d\n",host->h_length);    //地址長度
    for(i = 0 ; host->h_addr_list[i] != NULL ; i++)
    {
        //該地址以二進制形式存儲，轉換為字符串的形式
        printf("%s\n",inet_ntop(host->h_addrtype,host->h_addr_list[i],addr_p,NET_ADDR_STR_LEN));      //打印主機IP地址
    }
    return 0;
}</pre>