php resuming capacity for idm - php

Question

My code is this in php file for downloading any file but resume capability showing unknown plz can u suggest me the code for that functionality
its my php page to download a file, have to change code or what to do for changing resume capability in idm ?
if(!isset($_SESSION['user_id'])){
header('location:../index.php');}
$uname=$_SESSION['uname'];
$uid= $_SESSION['user_id'];
function output_file($file, $name, $mime_type='')
{
/*
This function takes a path to a file to output ($file), the filename that the browser will see ($name) and the MIME type of the file ($mime_type, optional).
*/
//Check the file premission
//if(!is_readable($file)) die('File not found or inaccessible!');
$size = filesize($file);
$name = rawurldecode($name);
/* Figure out the MIME type | Check in array */
$known_mime_types=array(
"pdf" => "application/pdf",
"txt" => "text/plain",
"html" => "text/html",
"htm" => "text/html",
"exe" => "application/octet-stream",
"zip" => "application/zip",
"doc" => "application/msword",
"xls" => "application/vnd.ms-excel",
"ppt" => "application/vnd.ms-powerpoint",
"gif" => "image/gif",
"png" => "image/png",
"jpeg"=> "image/jpg",
"jpg" => "image/jpg",
"php" => "text/plain"
);
if($mime_type==''){
$file_extension = strtolower(substr(strrchr($file,"."),1));
if(array_key_exists($file_extension, $known_mime_types)){
$mime_type=$known_mime_types[$file_extension];
} else {
$mime_type="application/force-download";
};
};
//turn off output buffering to decrease cpu usage
#ob_end_clean();
// required for IE, otherwise Content-Disposition may be ignored
if(ini_get('zlib.output_compression'))
ini_set('zlib.output_compression', 'Off');
header('Content-Type: ' . $mime_type);
header('Content-Disposition: attachment; filename="'.$name.'"');
header("Content-Transfer-Encoding: binary");
header('Accept-Ranges: bytes');
header('Content-Length: 2052595');
header('Content-Range: bytes 339843-2392437/2392438');
/* The three lines below basically make the
download non-cacheable */
header("Cache-control: private");
header('Pragma: private');
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
// multipart-download and download resuming support
if(isset($_SERVER['HTTP_RANGE']))
{
list($a, $range) = explode("=",$_SERVER['HTTP_RANGE'],2);
list($range) = explode(",",$range,2);
list($range, $range_end) = explode("-", $range);
$range=intval($range);
if(!$range_end) {
$range_end=$size-1;
} else {
$range_end=intval($range_end);
}
$new_length = $range_end-$range+1;
header("HTTP/1.1 206 Partial Content");
header("Content-Length: $new_length");
header("Content-Range: bytes $range-$range_end/$size");
} else {
$new_length=$size;
header("Content-Length: ".$size);
}
/* Will output the file itself */
$chunksize = 3*(1024*1024); //you may want to change this
$bytes_send = 0;
if ($file = fopen($file, 'r'))
{
if(isset($_SERVER['HTTP_RANGE']))
fseek($file, $range);
while(!feof($file) &&
(!connection_aborted()) &&
($bytes_send<$new_length)
)
{
$buffer = fread($file, $chunksize);
print($buffer); //echo($buffer); // can also possible
flush();
$bytes_send += strlen($buffer);
}
fclose($file);
} else
//If no permissiion
die('Error - can not open file.');
//die
die();
}
//Set the time out
set_time_limit(0);
$temp = explode("\\", $_REQUEST['filename']);
//path to the file
$file_path=$_REQUEST['filename'];
//Call the download function with file path,file name and file type
output_file($file_path, ''.$temp[3].'', 'text/plain');
?>

Answer 1

<?php
$uname=$_COOKIE["uname"];
//echo $uname;
$file=$_REQUEST['filename'];
$file_name="E:\\upload\\$uname\\$file";
$fid=$_REQUEST['fid'];
$con=mysql_connect("localhost","root","Net#123");
$db=mysql_select_db("file_storage",$con);
$query1=mysql_query("SELECT * FROM upload WHERE file_id=$fid");
$row1=mysql_fetch_array($query1);
if($row1)
{
$file_db=$row1['name'];
// If the requested file is exist
if(file_exists($file_name)){
// Get the file size
$file_size=filesize($file_name);
// Open the file
$fh=fopen($file_name, "r");
// Download speed in KB/s
$speed=1024;
//Initialize the range of bytes to be transferred
$start=0;
$end=$file_size-1;
//Check HTTP_RANGE variable
if(isset($_SERVER['HTTP_RANGE']) &&
preg_match('/^bytes=(\d+)-(\d*)/', $_SERVER['HTTP_RANGE'], $arr)){
// Starting byte
$start=$arr[1];
if($arr[2]){
// Ending byte
$end=$arr[2];
}
}
//Check if starting and ending byte is valid
if($start>$end || $start>=$file_size){
header("HTTP/1.1 416 Requested Range Not Satisfiable");
header("Content-Length: 0");
}
else{
// For the first time download
if($start==0 && $end==$file_size){
// Send HTTP OK header
header("HTTP/1.1 200 OK");
}
else{
// For resume download
// Send Partial Content header
header("HTTP/1.1 206 Partial Content");
// Send Content-Range header
header("Content-Range: bytes ".$start."-".$end."/".$file_size);
}
// Bytes left
$left=$end-$start+1;
// Send the other headers
header("Content-Type: application/octet-stream");
header("Accept-Ranges: bytes");
// Content length should be the bytes left
header("Content-Length: ".$left);
header("Content-Disposition: attachment; filename=".$file_db);
// Read file from the given starting bytes
fseek($fh, $start);
// Loop while there are bytes left
while($left>0){
// Bytes to be transferred
// according to the defined speed
$bytes=$speed*1024;
// Read file per size
echo fread($fh, $bytes);
// Flush the content to client
flush();
// Substract bytes left with the tranferred bytes
$left-=$bytes;
// Delay for 1 second
sleep(1);
}
}
fclose($fh);
}
else{
//If the requested file is not exist
//Display error message
echo "File not found!";
}
}
exit();
?>
This code worked for , files are downloading with resume capability...

Answer 2

Please see the RFC on headers on how to report your capabilities to your clients:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
14.5 Accept-Ranges
The Accept-Ranges response-header field allows the server to
indicate its acceptance of range requests for a resource:
Accept-Ranges = "Accept-Ranges" ":" acceptable-ranges
acceptable-ranges = 1#range-unit | "none"
Origin servers that accept byte-range requests MAY send
Accept-Ranges: bytes
but are not required to do so. Clients MAY generate byte-range
requests without having received this header for the resource
involved. Range units are defined in section 3.12.
Servers that do not accept any kind of range request for a
resource MAY send
Accept-Ranges: none
to advise the client not to attempt a range request.