php判断远程文件或网站是否能打开

//默认效果 print_r(get_headers("http://www.baidu.com/img/baidu_sylogo1.gif")); 结果： Array ( [0] => HTTP/1.1 200 OK [1] => Date: Thu, 02 Jun 2011 02:47:27 GMT [2] => Server: Apache [3] => P3P: CP=" OTI DSP COR IVA OUR IND COM " [4] => Set-Cookie: BAIDUID=7F6A5A2ED03878A7791C89C526966F3A:FG=1; expires=Fri, 01-Jun-12 02:47:27 GMT; max-age=31536000; path=/; domain=.baidu.com; version=1 [5] => Last-Modified: Thu, 20 Jan 2011 07:15:35 GMT [6] => ETag: "65e-49a41e65933c0" [7] => Accept-Ranges: bytes [8] => Content-Length: 1630 [9] => Cache-Control: max-age=315360000 [10] => Expires: Sun, 30 May 2021 02:47:27 GMT [11] => Connection: Close [12] => Content-Type: image/gif ) //加参数1的效果 print_r(get_headers("http://www.baidu.com/img/baidu_sylogo1.gif", 1)); 结果： Array ( [0] => HTTP/1.1 200 OK [Date] => Thu, 02 Jun 2011 02:49:28 GMT [Server] => Apache [P3P] => CP=" OTI DSP COR IVA OUR IND COM " [Set-Cookie] => BAIDUID=4D875812FC482C0ADE4F5C17068849EE:FG=1; expires=Fri, 01-Jun-12 02:49:28 GMT; max-age=31536000; path=/; domain=.baidu.com; version=1 [Last-Modified] => Thu, 20 Jan 2011 07:15:35 GMT [ETag] => "65e-49a41e65933c0" [Accept-Ranges] => bytes [Content-Length] => 1630 [Cache-Control] => max-age=315360000 [Expires] => Sun, 30 May 2021 02:49:28 GMT [Connection] => Close [Content-Type] => image/gif ) 怎么样，get_headers函数还是不错的吧，不过既然效率有问题，那只好不优先考虑了，curl就不错，下面看看curl的做法 function check_remote_file_exists($url) { $curl = curl_init($url); // 不取回数据 curl_setopt($curl, CURLOPT_NOBODY, true); curl_setopt($curl, CURLOPT_CUSTOMREQUEST, 'GET'); //不加这个会返回403，加了才返回正确的200，原因不明 // 发送请求 $result = curl_exec($curl); $found = false; // 如果请求没有发送失败 if ($result !== false) { // 再检查http响应码是否为200 $statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE); if ($statusCode == 200) { $found = true; } } curl_close($curl); return $found; } $exists = check_remote_file_exists('http://www.baidu.com/img/baidu_sylogo1.gif'); echo $exists ? '存在' : '不存在'; $exists = check_remote_file_exists('http://www.baidu.com/test.jpg'); echo $exists ? '存在' : '不存在'