C语言解析dns

直接上代码：

#include <stdio.h>
#include <sys/socket.h>
#include <netdb.h>
#include <string.h>
#include <arpa/inet.h>

int main()
{
    struct hostent *hptr = NULL;
    char str[32];

    const char * ptr = "";

    if( (hptr = gethostbyname(ptr) ) == NULL )  //得到域名相关信息，失败返回NULL
    {
        printf("gethostbyname error : %s\n", hstrerror(h_errno)); //打印错误字符串
        return -1;
    }

    struct sockaddr_in me;
    int i = 0;
    for (; hptr->h_addr_list[i]; i++) {  //h_addr_list[i]中有多个ip，则h_addr_list[i]不为空
        memset(&me, 0, sizeof(struct sockaddr_in));
        memcpy(&me.sin_addr, hptr->h_addr_list[i], hptr->h_length);
        printf("address:%s\n", inet_ntop(hptr->h_addrtype, &me.sin_addr, str, sizeof(str)));
        printf("hptr->h_name:%s\n", hptr->h_name);
        printf("me.sin_addr.s_addr [%u]\n", ntohl(me.sin_addr.s_addr)); //网络序转换成主机序
        printf("\n");
    }

    return 0;
}

结果：

[root@localhost util]# ./a.out
address:180.97.33.108
hptr->h_name:www.a.shifen.com
me.sin_addr.s_addr [3026264428] //二进制网络序转成的主机序地址

address:180.97.33.107
hptr->h_name:www.a.shifen.com
me.sin_addr.s_addr [3026264427]