<?php
/*
?* PHP下載斷點續傳
?*/
function dl_file_resume($file){
?
??? //檢測文件是否存在
??? if (!is_file($file)) { die("<b>404 File not found!</b>"); }
?????
??? $len = filesize($file);//獲取文件大小
??? $filename = basename($file);//獲取文件名字
??? $file_extension = strtolower(substr(strrchr($filename,"."),1));//獲取文件擴展名
?????
??? //根據擴展名 指出輸出瀏覽器格式
??? switch( $file_extension ) {
??????? case "exe": $ctype="application/octet-stream"; break;
??????? case "zip": $ctype="application/zip"; break;
??????? case "mp3": $ctype="audio/mpeg"; break;
??????? case "mpg":$ctype="video/mpeg"; break;
??????? case "avi": $ctype="video/x-msvideo"; break;
??????? default: $ctype="application/force-download";
??? }
?????
??? //Begin writing headers
??? header("Cache-Control:");
??? header("Cache-Control: public");
?????
??? //設置輸出瀏覽器格式
??? header("Content-Type: $ctype");
??? if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE")) {//如果是IE瀏覽器
??????? # workaround for IE filename bug with multiple periods / multiple dots in filename
??????? # that adds square brackets to filename - eg. setup.abc.exe becomes setup[1].abc.exe
??????? $iefilename = preg_replace('/\./', '%2e', $filename, substr_count($filename, '.') - 1);
??????? header("Content-Disposition: attachment; filename=\"$iefilename\"");
??? } else {
??????? header("Content-Disposition: attachment; filename=\"$filename\"");
??? }
??? header("Accept-Ranges: bytes");
?????
??? $size=filesize($file);
??? //如果有$_SERVER['HTTP_RANGE']參數
??? if(isset($_SERVER['HTTP_RANGE'])) {
/*?? ---------------------------
?? Range頭域 　　Range頭域可以哀求實體的一個或者多個子范圍.例如, 　　表示頭500個字節：bytes=0-499 　　表示第二個500字節：bytes=500-999 　　表示最后500個字節：bytes=-500 　　表示500字節以后的范圍：bytes=500- 　　第一個和最后一個字節：bytes=0-0,-1 　　同時指定幾個范圍：bytes=500-600,601-999 　　但是服務器可以忽略此哀求頭,如果無條件GET包含Range哀求頭,響應會以狀態碼206(PartialContent)返回而不是以200 (OK).
?? ---------------------------*/
???
// 斷點后再次連接 $_SERVER['HTTP_RANGE'] 的值 bytes=4390912-
???
??????? list($a, $range)=explode("=",$_SERVER['HTTP_RANGE']);
?? //if yes, download missing part
??????? str_replace($range, "-", $range);//這句干什么的呢....
?? $size2=$size-1;//文件總字節數
??????? $new_length=$size2-$range;//獲取下次下載的長度
??????? header("HTTP/1.1 206 Partial Content");
??????? header("Content-Length: $new_length");//輸入總長
??????? header("Content-Range: bytes $range$size2/$size");//Content-Range: bytes 4908618-4988927/4988928?? 95%的時候
??? } else {//第一次連接
??????? $size2=$size-1;
??????? header("Content-Range: bytes 0-$size2/$size"); //Content-Range: bytes 0-4988927/4988928
??????? header("Content-Length: ".$size);//輸出總長
??? }
??? //打開文件
??? $fp=fopen("$file","rb");
??? //設置指針位置
??? fseek($fp,$range);
??? //虛幻輸出
??? while(!feof($fp)){
??????? //設置文件最長執行時間
??????? set_time_limit(0);
??????? print(fread($fp,1024*8));//輸出文件
??????? flush();//輸出緩沖
??????? ob_flush();
??? }
??? fclose($fp);
??? exit;
}
?
dl_file_resume("1.zip");//同級目錄的1.zip 文件
?
//---------------------------------------
?
//不支持斷點續傳的文件下載.
?
//---------------------------------------
?
downFile("1.zip");
?
function downFile($sFilePath)
{
?? if(file_exists($sFilePath)){
?????? $aFilePath=explode("/",str_replace("\\","/",$sFilePath),$sFilePath);
?????? $sFileName=$aFilePath[count($aFilePath)-1];
?????? $nFileSize=filesize ($sFilePath);
?????? header ("Content-Disposition: attachment; filename=" . $sFileName);
?????? header ("Content-Length: " . $nFileSize);
?????? header ("Content-type: application/octet-stream");
?????? readfile($sFilePath);
?? }
?? else
?? {
?????? echo("文件不存在!");
?? }
}
?>