require_once('download.class.php'); 
date_default_timezone_set('Asia/Shanghai'); 
error_reporting(E_STRICT); 
 
function errorHandler($errno, $errstr, $errfile, $errline) { 
    echo '<p>error:', $errstr, '</p>'; 
    exit(); 
} 
 
set_error_handler('errorHandler'); 
define('IS_DEBUG', true); 
 
$filePath = 'test.zip'; 
$mimeType = 'audio/x-matroska'; 
$range = isset($_SERVER['HTTP_RANGE']) ? $_SERVER['HTTP_RANGE'] : null; 
if (IS_DEBUG) { 
//    $range = "bytes=1000-1999\n2000"; 
//    $range = "bytes=1000-1999,2000";  
//    $range = "bytes=1000-1999,-2000";  
//    $range = "bytes=1000-1999,2000-2999";  
} 
set_time_limit(0); 
$transfer = new Transfer($filePath, $mimeType, $range); 
if (IS_DEBUG) { 
    $transfer->setIsLog(true); 
} 
$transfer->send();
 

download.class.php

/** 
 * 檔案傳輸，支援斷點續傳。 
 * 2g以上超大檔案也有效 
 * @author MoXie 
 */ 
class Transfer { 
 
    /** 
     * 緩衝單元 
     */ 
    const BUFF_SIZE = 5120; // 1024 * 5 
 
    /** 
     * 檔案地址 
     * @var <String> 
     */ 
 
    private $filePath; 
 
    /** 
     * 檔案大小 
     * @var <String> Php超大數字 字串形式描述 
     */ 
    private $fileSize; 
 
    /** 
     * 檔案型別 
     * @var <String> 
     */ 
    private $mimeType; 
 
    /** 
     * 請求區域（範圍） 
     * @var <String> 
     */ 
    private $range; 
 
    /** 
     * 是否寫入日誌 
     * @var <Boolean> 
     */ 
    private $isLog = false; 
 
    /** 
     * 
     * @param <String> $filePath 檔案路徑 
     * @param <String> $mimeType  檔案型別 
     * @param <String> $range 請求區域（範圍） 
     */ 
    function __construct($filePath, $mimeType = null, $range = null) { 
        $this->filePath = $filePath; 
        $this->fileSize = sprintf('%u', filesize($filePath)); 
        $this->mimeType = ($mimeType != null) ? $mimeType : "application/octet-stream"; //  bin 
        $this->range = trim($range); 
    } 
 
    /** 
     *  獲取檔案區域 
     * @return <Map> {'start':long,'end':long} or null 
     */ 
    private function getRange() { 
        /** 
         *  Range: bytes=-128 
         *  Range: bytes=-128 
         *  Range: bytes=28-175,382-399,510-541,644-744,977-980 
         *  Range: bytes=28-175\n380 
         *  type 1 
         *  RANGE: bytes=1000-9999 
         *  RANGE: bytes=2000-9999 
         *  type 2 
         *  RANGE: bytes=1000-1999 
         *  RANGE: bytes=2000-2999 
         *  RANGE: bytes=3000-3999 
         */ 
        if (!empty($this->range)) { 
            $range = preg_replace('/[\s|,].*/', '', $this->range); 
            $range = explode('-', substr($range, 6)); 
            if (count($range) < 2) { 
                $range[1] = $this->fileSize; // Range: bytes=-100 
            } 
            $range = array_combine(array('start', 'end'), $range); 
            if (empty($range['start'])) { 
                $range['start'] = 0; 
            } 
            if (!isset($range['end']) || empty($range['end'])) { 
                $range['end'] = $this->fileSize; 
            } 
            return $range; 
        } 
        return null; 
    } 
 
    /** 
     * 向客戶端傳送檔案 
     */ 
    public function send() { 
        $fileHande = fopen($this->filePath, 'rb'); 
        if ($fileHande) { 
            // setting 
            ob_end_clean(); // clean cache 
            ob_start(); 
            ini_set('output_buffering', 'Off'); 
            ini_set('zlib.output_compression', 'Off'); 
            $magicQuotes = get_magic_quotes_gpc(); 
//            set_magic_quotes_runtime(0); 
            // init 
            $lastModified = gmdate('D, d M Y H:i:s', filemtime($this->filePath)) . ' GMT'; 
            $etag = sprintf('w/"%s:%s"', md5($lastModified), $this->fileSize); 
            $ranges = $this->getRange(); 
            // headers 
            header(sprintf('Last-Modified: %s', $lastModified)); 
            header(sprintf('ETag: %s', $etag)); 
            header(sprintf('Content-Type: %s', $this->mimeType)); 
            $disposition = 'attachment'; 
            if (strpos($this->mimeType, 'image/') !== FALSE) { 
                $disposition = 'inline'; 
            } 
            header(sprintf('Content-Disposition: %s; filename="%s"', $disposition, basename($this->filePath))); 
 
            if ($ranges != null) { 
                if ($this->isLog) { 
                    $this->log(json_encode($ranges) . ' ' . $_SERVER['HTTP_RANGE']); 
                } 
                header('HTTP/1.1 206 Partial Content'); 
                header('Accept-Ranges: bytes'); 
                header(sprintf('Content-Length: %u', $ranges['end'] - $ranges['start'])); 
                header(sprintf('Content-Range: bytes %s-%s/%s', $ranges['start'], $ranges['end'], $this->fileSize)); 
                // 
                fseek($fileHande, sprintf('%u', $ranges['start'])); 
            } else { 
                header("HTTP/1.1 200 OK"); 
                header(sprintf('Content-Length: %s', $this->fileSize)); 
            } 
            // read file 
            $lastSize = 0; 
            while (!feof($fileHande) && !connection_aborted()) { 
                $lastSize = sprintf("%u", bcsub($this->fileSize, sprintf("%u", ftell($fileHande)))); 
                if (bccomp($lastSize, self::BUFF_SIZE) > 0) { 
                    $lastSize = self::BUFF_SIZE; 
                } 
                echo fread($fileHande, $lastSize); 
                ob_flush(); 
                flush(); 
            } 
            set_magic_quotes_runtime($magicQuotes); 
            ob_end_flush(); 
        } 
        if ($fileHande != null) { 
            fclose($fileHande); 
        } 
    } 
 
    /** 
     * 設定記錄 
     * @param <Boolean> $isLog  是否記錄 
     */ 
    public function setIsLog($isLog = true) { 
        $this->isLog = $isLog; 
    } 
 
    /** 
     * 記錄 
     * @param <String> $msg  記錄資訊 
     */ 
    private function log($msg) { 
        try { 
            $handle = fopen('transfer_log.txt', 'a'); 
            fwrite($handle, sprintf('%s : %s' . PHP_EOL, date('Y-m-d H:i:s'), $msg)); 
            fclose($handle); 
        } catch (Exception $e) { 
            // null; 
        } 
    } 
 
}
 

這樣就實現了大檔案斷點下載功能了，有興趣的朋友可以學起