文章转载，话不多说，代码其实可以改的更好点。

<?php
$webfile = "sitexml.txt";
$opensite = fopen($webfile, 'r');

function curl($url) {
	/*
	* 测试用的浏览器信息
	*

	*/
	$browsers = array (

		"user_agent" => "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.6) Gecko/20091201 Firefox/3.5.6 (.NET CLR 3.5.30729)",
		"language" => "en-us,en;q=0.5"
	);
	$ch = curl_init();
	// 设置 url
	curl_setopt($ch, CURLOPT_URL, $url);
	// 设置浏览器的特定header
	//CURLOPT_HTTPHEADER: An array of HTTP header fields to set.
	//curl_setopt($ch, CURLOPT_HTTPHEADER, 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.6) Gecko/20091201 Firefox/3.5.6 (.NET CLR 3.5.30729)');
	curl_setopt($ch, CURLOPT_HTTPHEADER, array (
		"User-Agent: {$browsers['user_agent']}",
		"Accept-Language: {$browsers['language']}"
	));

	// 页面内容我们并不需要
	curl_setopt($ch, CURLOPT_NOBODY, 1);
	// 只需返回HTTP header
	curl_setopt($ch, CURLOPT_HEADER, 1);
	// 返回结果，而不是输出它
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	//执行curl操作
	//return (curl_exec($ch)!==false) ? true : false;
	$output = curl_exec($ch);
	return $output;
	curl_close($ch);
}
while (!feof($opensite)) {
	$onesite = fgets($opensite, 4096);
	$onesite = str_replace("\n", "", $onesite);
	$url = $onesite . "/sitemap.xml";
	if (!empty ($onesite)) {

		echo "[URL]: $url<br>";
		echo curl($url);

		if (curl($url) == false) {
			echo '<FONT color=#ff0000>' . "网站不能打开" . '</font>' . "<br>";

		}
		preg_match('/HTTP\/1.1\s*(\d+)[\s\S]+/', curl($url), $http_status);
		//print_r($http_status);
		if ($http_status[1] == 200) {
			echo $url . "存在sitemap" . "<br>";
		}
		if ($http_status[1] == 301) {
			$url = 'www.' . $url;
			preg_match('/HTTP\/1.1\s*(\d+)[\s\S]+/', curl($url), $http_status);
			if ($http_status[1] == 200) {
				echo $url . "存在sitemap" . "<br>";
			} else {
				echo '<FONT color=#ff0000>' . $url . "没有sitemap" . '</font>';
			}
		}
		if ($http_status[1] == (404|400|403|500|501|502|503|504|505)) {
			echo '<FONT color=#ff0000>' . $url . "没有sitemap" . '</font>';

		}

		echo "<br><br>";
	}
}
?>