php有很多方法可以获取远程文件大小的,最常用的就有fsockopen、file_get_contents、curl函数,下面我来给各位总结一下.

1、fsockopen,代码如下:

1. <?php
2. function getFileSize($url){
3. $url = parse_url($url);
4. if($fp = @fsockopen($url['host'],emptyempty($url['port'])?80:$url['port'],$error)){
5. fputs($fp,"GET ".(emptyempty($url['path'])?'/':$url['path'])." HTTP/1.1rn");
6. fputs($fp,"Host:$url[host]rnrn");
7. while(!feof($fp)){
8. $tmp = fgets($fp);
9. if(trim($tmp) == ''){
10. break;
11. }else if(preg_match('/Content-Length:(.*)/si',$tmp,$arr)){
12. return trim($arr[1]);
13. }
14. }
15. return null;
16. }else{
17. return null;
18. }
19. }
20. //调用方法
21. echo getFileSize("http://www.phpfensi.com/")
22. ?>

2、使用file_get_contents(),代码如下:

1. <?php
2. $file = file_get_contents($url);
3. echo strlen($file);
4. ?>

3. 使用get_headers(),代码如下:

1. <?php
2. $header_array = get_headers($url, true);
3. //返回结果
4. Array
5. (
6. [0] => HTTP/1.1 200 OK
7. [Date] => Sat, 29 May 2004 12:28:14 GMT
8. [Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux)
9. [Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT
10. [ETag] => "3f80f-1b6-3e1cb03b"
11. [Accept-Ranges] => bytes
12. [Content-Length] => 438
13. [Connection] => close
14. [Content-Type] => text/html
15. )
16. $size = $header_array['Content-Length'];
17. echo $size;
18. ?>

4.curl,代码如下:

1. function remote_filesize($uri,$user='',$pw='')
2. {
3. // start output buffering
4. ob_start();
5. // initialize curl with given uri
6. $ch = curl_init($uri);
7. // make sure we get the header
8. curl_setopt($ch, CURLOPT_HEADER, 1);
9. // make it a http HEAD request
10. curl_setopt($ch, CURLOPT_NOBODY, 1);
11. // if auth is needed, do it here
12. if (!emptyempty($user) && !emptyempty($pw))
13. {
14. $headers = array('Authorization: Basic ' . base64_encode($user.':'.$pw));
15. curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
16. }
17. $okay = curl_exec($ch);
18. curl_close($ch);
19. // get the output buffer
20. $head = ob_get_contents();
21. // clean the output buffer and return to previous
22. // buffer settings
23. ob_end_clean();
24. echo '<br>head-->'.$head.'<----end <br>';
25. // gets you the numeric value from the Content-Length
26. // field in the http header
27. $regex = '/Content-Length:s([0-9].+?)s/';
28. $count = preg_match($regex, $head, $matches);
29. // if there was a Content-Length field, its value
30. // will now be in $matches[1]
31. if (isset($matches[1]))
32. { //开源代码phpfensi.com
33. $size = $matches[1];
34. }
35. else
36. {
37. $size = 'unknown';
38. }
39. //$last=round($size/(1024*1024),3);
40. //return $last.' MB';
41. return $size;
42. }