php获取远程文件大小

获取本地文件大小filesize()就可以了,但是如何获取远程文件的大小呢? 这里介绍三个方法来获取远程文件的大小.

方法1:get_headers

[php]

<?php

get_headers($url,true);

//返回结果

Array

(

[0] => HTTP/1.1 200 OK

[Date] => Sat, 29 May 2004 12:28:14 GMT

[Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux)

[Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT

[ETag] => "3f80f-1b6-3e1cb03b"

[Accept-Ranges] => bytes

[Content-Length] => 438

[Connection] => close

[Content-Type] => text/html

)

?>

此处可以直接根据Content-Length来获取到远程文件的大小了.

方法2:curl

[php]

function remote_filesize($uri,$user='',$pw='')

{

// start output buffering

ob_start();

// initialize curl with given uri

$ch = curl_init($uri);

// make sure we get the header

curl_setopt($ch, CURLOPT_HEADER, 1);

// make it a http HEAD request

curl_setopt($ch, CURLOPT_NOBODY, 1);

// if auth is needed, do it here

if (!emptyempty($user) && !emptyempty($pw))

{

$headers = array('Authorization: Basic ' . base64_encode($user.':'.$pw));

curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

}

$okay = curl_exec($ch);

curl_close($ch);

// get the output buffer

$head = ob_get_contents();

// clean the output buffer and return to previous

// buffer settings

ob_end_clean();

echo '<br>head-->'.$head.'<----end <br>';

// gets you the numeric value from the Content-Length

// field in the http header

$regex = '/Content-Length:\s([0-9].+?)\s/';

$count = preg_match($regex, $head, $matches);

// if there was a Content-Length field, its value

// will now be in $matches[1]

if (isset($matches[1]))

{

$size = $matches[1];

}

else

{

$size = 'unknown';

}

//$last=round($size/(1024*1024),3);

//return $last.' MB';

return $size;

}

方法3:socket

[php]

function getFileSize($url)

{

$url = parse_url($url);

if($fp = @fsockopen($url['host'],emptyempty($url['port'])?80:$url['port'],$error))

{

fputs($fp,"GET ".(emptyempty($url['path'])?'/':$url['path'])." HTTP/1.1\r\n");

fputs($fp,"Host:$url[host]\r\n\r\n");

while(!feof($fp))

{

$tmp = fgets($fp);

if(trim($tmp) == '')

{

break;

}

elseif(preg_match('/Content-Length:(.*)/si',$tmp,$arr))

{

return trim($arr[1]);

}

}

return null;

}

else

{

return null;

}

}

方法4:file_get_contents

[php]

$fCont = file_get_contents("http://www.mg27.com/1.html");

echo strlen($fCont)/1024;

以上四种方法

curl > fsock > file_get_contents > getheader