Download a file from php-mysql database

To download a file stored in php-mysql database first of all we have to read the filename and check the filetype. Further we have to set the Content-Type of the file according to its filetype ( check extention ) and set appropriate headers. But you don't worry. You don't need to do anything.

Simply call the download.php file by passing filename ( which is to be downloaded ). And it works for you. That's it !!   The full code is given here !!

download.php

 
 <?php
 function download_file($file){
  if (!is_file($file)) { die("404 File not found"); }

  //Gather relevent info about file
  $len = filesize($file);
  $name = basename($file);
  $ext = strtolower(substr(strrchr($name,"."),1));

  //This will set the appropriate Content-Type
  switch( $ext ) {
   case "pdf": $ctype="application/pdf"; break;
   case "exe": $ctype="application/octet-stream"; break;
   case "zip": $ctype="application/zip"; break;
   case "doc": $ctype="application/msword"; break;
   case "xls": $ctype="application/vnd.ms-excel"; break;
   case "ppt": $ctype="application/vnd.ms-powerpoint"; break;
   case "gif": $ctype="image/gif"; break;
   case "png": $ctype="image/png"; break;
   case "jpeg":
   case "jpg": $ctype="image/jpg"; break;
   case "mp3": $ctype="audio/mpeg"; break;
   case "wav": $ctype="audio/x-wav"; break;
   case "mpeg":
   case "mpg":
   case "mpe": $ctype="video/mpeg"; break;
   case "mov": $ctype="video/quicktime"; break;
   case "avi": $ctype="video/x-msvideo"; break;

  //Following are extensions that shouldn't be downloaded
   case "php":
   case "htm":
   case "html":
   case "txt": die("Cannot be used for ". $ext ." files!");
   break;

   default: $ctype="application/force-download";
  }

  //Begin writing headers
  header("Pragma: public");
  header("Expires: 0");
  header("Cache-Control: must-revalidate, 
  post-check=0, pre-check=0");
  header("Cache-Control: public");
  header("Content-Description: File Transfer");

  //Use the switch-generated Content-Type
  header("Content-Type: $ctype");

  //Force the download
  $header="Content-Disposition:attachment;filename=".$name;
  header($header );
  header("Content-Transfer-Encoding: binary");
  header("Content-Length: ".$len);
  @readfile($file);
  exit;
 }
 
 //Function call
 $file =$_REQUEST['file'];
 download_file($file);

 ?>

The Html Link to download the file
<a href="download.php?file=filename.doc">Download</a>