PHP下載文件的函數(shù)實例代碼

    本文通過實例代碼給大家介紹php下載文件的函數(shù)相關(guān)知識，介紹的非常詳解，具有參考借鑒價值，感興趣的朋友一起學(xué)習(xí)吧
    通過函數(shù)完成下載文件的PHP功能代碼
    function download($url, $filename) {
    // 獲得文件大小, 防止超過2G的文件, 用sprintf來讀
    $filesize = sprintf ( "%u", filesize ( $url ) );
    if (! $filesize) {
    return;
    }
    header ( "Content-type:application/octet-stream\n" ); //application/octet-stream
    header ( "Content-type:unknown/unknown;" );
    header ( "Content-disposition: attachment; filename=\"" . $filename . "\"" );
    header ( 'Content-transfer-encoding: binary' );
    if ($range = getenv ( 'HTTP_RANGE' )) { // 當(dāng)有偏移量的時候，采用206的斷點續(xù)傳頭
    $range = explode ( '=', $range );
    $range = $range [1];
    header ( "HTTP/1.1 206 Partial Content" );
    header ( "Date: " . gmdate ( "D, d M Y H:i:s" ) . " GMT" );
    header ( "Last-Modified: " . gmdate ( "D, d M Y H:i:s", filemtime ( $url ) ) . " GMT" );
    header ( "Accept-Ranges: bytes" );
    header ( "Content-Length:" . ($filesize - $range) );
    header ( "Content-Range: bytes " . $range . ($filesize - 1) . "/" . $filesize );
    header ( "Connection: close" . "\n\n" );
    else {
    header ( "Content-Length:" . $filesize . "\n\n" );
    $range = 0; }
    loadFile ( $url );}
    function loadFile($filename, $retbytes = true) {
    $buffer = ''; $cnt = 0; $handle = fopen ( $filename, 'rb' );
    if ($handle === false) { return false;
    } while ( ! feof ( $handle ) ) {
    $buffer = fread ( $handle, 1024 * 1024 );
    echo $buffer;
    ob_flush ();
    flush ();
    if ($retbytes) {
    $cnt += strlen ( $buffer );
    }
    }
    $status = fclose ( $handle );
    if ($retbytes && $status) {
    return $cnt; // return num. bytes delivered like readfile() does.
    }
    return $status;}
    輸入2個參數(shù)即可完成下載 download($url, $filename)
    以上所述是小編給大家介紹的PHP下載文件的函數(shù)實例代碼的相關(guān)知識，希望對大家有所幫助