PHP獲取遠程文件大小

獲取本地文件大小filesize()就可以了,但是如何獲取遠程文件的大小呢? 這里介紹四個方法來獲取遠程文件的大小.

方法1:get_headers

<?php 
get_headers($url,true); 

//返回結果 
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 
) 
?> 

此處可以直接根據Content-Length來獲取到遠程文件的大小了.

方法2:curl

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:fsock

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

$fCont = file_get_contents("http://www.cnmiss.cn/"); 
echo strlen($fCont)/1024; 

以上四種方法