gethostbyname不能返回IP地址

为什么如下这段代码不能成功得到IP地址，打印出NULL了，环境为windows，dev c++ 和 VC 都失败了
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#pragma   comment(lib,"WS2_32.lib")

int main(int argc, char *argv[]) {
    struct hostent * remotehost;
    remotehost = gethostbyname("www.baidu.com");
    if (NULL == remotehost) printf("NULL\n");
    return 0;
}