php获取https下的内容

直接用file_get_contents，会报错；

$url = ('https://xxx.com");
file_get_contents($url);

错误：

Warning: file_get_contents(https://xxx.com) [function.file-get-contents]: failed to open stream: No such file   or directory in D:wampwwwgrabber_clientindex.php on line 3

用curl的方式是可以的：

<?php
$url = ('https://xxx.com');
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
$result = curl_exec($ch);
print_r($result);
?>

重点是以下两句：
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); 
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);