<?php
/**********************************************************************
**
** A class to download files
** Version 1.0
** Features :
** - hide the real path to the file
** - allow / disallow download resuming
** - partial download (useful for download managers)
** - rename the file on the fly
** - limit download speed
**
** Author: Mourad Boufarguine / EPT <mourad.boufarguine@gmail.com>
**
** License: Public Domain
** Warranty: None
**
***********************************************************************/
class Bf_Download{
// just one array to gather all the properties of a download
private $properties = array("path" => "", // the real path to the file
"name" => "", // to rename the file on the fly
"extension" => "", // extension of the file
"type" => "", // the type of the file
"size" => "", // the file size
"resume" => "", // allow / disallow resuming
"max_speed" => "" // speed limit (ko) ( 0 = no limit)
);
// the constructor
public function __construct($path, $name="", $resume="off", $max_speed=0){ // by default, resuming is NOT allowed and there is no speed limit
$name = ($name == "") ? substr(strrchr("/".$path,"/"),1) : $name; // if "name" is not specified, th file won't be renamed
$file_extension = strtolower(substr(strrchr($path,"."),1)); // the file extension
switch( $file_extension ) { // the file type
case "mp3": $content_type="audio/mpeg"; break;
case "mpg": $content_type="video/mpeg"; break;
case "avi": $content_type="video/x-msvideo"; break;
case "wmv": $content_type="video/x-ms-wmv";break;
case "wma": $content_type="audio/x-ms-wma";break;
default: $content_type="application/force-download";
}
$file_size = filesize($path); // the file size
$this->properties = array(
"path" => $path,
"name" => $name,
"extension" =>$file_extension,
"type"=>$content_type,
"size" => $file_size,
"resume" => $resume,
"max_speed" => $max_speed
);
}
// public function to get the value of a property
public function get_property ($property){
if ( array_key_exists($property,$this->properties) ) // check if the property do exist
return $this->properties[$property]; // get its value
else
return null; // else return null
}
// public function to set the value of a property
public function set_property ($property, $value){
if ( array_key_exists($property, $this->properties) ){ // check if the property do exist
$this->properties[$property] = $value; // set the new value
return true;
} else
return false;
}
// public function to start the download
public function download_file(){
if ( $this->properties['path'] == "" ) // if the path is unset, then error !
echo "Nothing to download!";
else {
// if resuming is allowed ...
if ($this->properties["resume"] == "on") {
if(isset($_SERVER['HTTP_RANGE'])) { // check if http_range is sent by browser (or download manager)
list($a, $range)=explode("=",$_SERVER['HTTP_RANGE']);
ereg("([0-9]+)-([0-9]*)/?([0-9]*)",$range,$range_parts); // parsing Range header
$byte_from = $range_parts [1]; // the download range : from $byte_from ...
$byte_to = $range_parts [2]; // ... to $byte_to
} else
if(isset($_ENV['HTTP_RANGE'])) { // some web servers do use the $_ENV['HTTP_RANGE'] instead
list($a, $range)=explode("=",$_ENV['HTTP_RANGE']);
ereg("([0-9]+)-([0-9]*)/?([0-9]*)",$range,$range_parts); // parsing Range header
$byte_from = $range_parts [1]; // the download range : from $byte_from ...
$byte_to = $range_parts [2]; // ... to $byte_to
}else{
$byte_from = 0; // if no range header is found, download the whole file from byte 0 ...
$byte_to = $this->properties["size"] - 1; // ... to the last byte
}
if ($byte_to == "") // if the end byte is not specified, ...
$byte_to = $this->properties["size"] -1; // ... set it to the last byte of the file
header("HTTP/1.1 206 Patial Content"); // send the partial content header
// ... else, download the whole file
} else {
$byte_from = 0;
$byte_to = $this->properties["size"] - 1;
}
$download_range = $byte_from."-".$byte_to."/".$this->properties["size"]; // the download range
$download_size = $byte_to - $byte_from; // the download length
// download speed limitation
if (($speed = $this->properties["max_speed"]) > 0) // determine the max speed allowed ...
$sleep_time = (8 / $speed) * 1e6; // ... if "max_speed" = 0 then no limit (default)
else
$sleep_time = 0;
// send the headers
header("Pragma: public"); // purge the browser cache
header("Expires: 0"); // ...
header("Cache-Control:"); // ...
header("Cache-Control: public"); // ...
header("Content-Description: File Transfer"); //
header("Content-Type: ".$this->properties["type"]); // file type
header('Content-Disposition: attachment; filename="'.$this->properties["name"].'";');
header("Content-Transfer-Encoding: binary"); // transfer method
header("Content-Range: $download_range"); // download range
header("Content-Length: $download_size"); // download length
// send the file content
$fp=fopen($this->properties["path"],"r"); // open the file
if(!fp) exit; // if $fp is not a valid stream resource, exit
fseek($fp,$byte_from); // seek to start of missing part
while(!feof($fp)){ // start buffered download
set_time_limit(0); // reset time limit for big files (has no effect if php is executed in safe mode)
print(fread($fp,1024*8)); // send 8ko
flush();
usleep($sleep_time); // sleep (for speed limitation)
}
fclose($fp); // close the file
exit;
}
}
}
?>
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