php 下载文件的函数 - carlo-jie

通过函数完成下载文件的PHP功能代码<br><br>function download($url, $filename) {<br>    // 获得文件大小, 防止超过2G的文件, 用sprintf来读<br>    $filesize = sprintf ( "%u", filesize ( $url ) );<br>    if (! $filesize) {<br>        return;<br>    }<br>    header ( "Content-type:application/octet-stream\n" ); //application/octet-stream<br>    header ( "Content-type:unknown/unknown;" );<br>    header ( "Content-disposition: attachment; filename=\"" . $filename . "\"" );<br>    header ( 'Content-transfer-encoding: binary' );<br>    if ($range = getenv ( 'HTTP_RANGE' )) { // 当有偏移量的时候，采用206的断点续传头<br>        $range = explode ( '=', $range );<br>        $range = $range [1];<br><br>        header ( "HTTP/1.1 206 Partial Content" );<br>        header ( "Date: " . gmdate ( "D, d M Y H:i:s" ) . " GMT" );<br>        header ( "Last-Modified: " . gmdate ( "D, d M Y H:i:s", filemtime ( $url ) ) . " GMT" );<br>        header ( "Accept-Ranges: bytes" );<br>        header ( "Content-Length:" . ($filesize - $range) );<br>        header ( "Content-Range: bytes " . $range . ($filesize - 1) . "/" . $filesize );<br>        header ( "Connection: close" . "\n\n" );<br>    } else {<br>        header ( "Content-Length:" . $filesize . "\n\n" );<br>        $range = 0;<br>    }<br>    loadFile ( $url );<br>}<br><br>function loadFile($filename, $retbytes = true) {<br>    $buffer = '';<br>    $cnt = 0;<br>    $handle = fopen ( $filename, 'rb' );<br>    if ($handle === false) {<br>        return false;<br>    }<br>    while ( ! feof ( $handle ) ) {<br>        $buffer = fread ( $handle, 1024 * 1024 );<br>        echo $buffer;<br>        ob_flush ();<br>        flush ();<br>        if ($retbytes) {<br>            $cnt += strlen ( $buffer );<br>        }<br>    }<br>    $status = fclose ( $handle );<br>    if ($retbytes && $status) {<br>        return $cnt; // return num. bytes delivered like readfile() does.<br>    }<br>    return $status;<br>}<br>输入2个参数即可完成下载

download($url, $filename)