Script básico de forçar download em php.

Forçar Download

<?php 
//$file = "/folder/filename.ext";
function force_download($file) {
$ext = explode(".", $file);
switch($ext[sizeof($ext)-1]) {
  case 'jar': 
    $mime = "application/java-archive";
    break;
  case 'zip': 
    $mime = "application/zip"; 
    break;
  case 'jpeg': 
    $mime = "image/jpeg";
    break; 
  case 'jpg': 
    $mime = "image/jpg";
    break;
  case 'jad':
    $mime = "text/vnd.sun.j2me.app-descriptor"; 
    break;
  case "gif": 
    $mime = "image/gif"; 
    break;
  case "png": 
    $mime = "image/png";
    break; 
  case "pdf": 
    $mime = "application/pdf";
    break;
  case "txt": 
    $mime = "text/plain"; 
    break;
  case "doc": 
    $mime = "application/msword";
    break;
  case "ppt": 
    $mime = "application/vnd.ms-powerpoint"; 
    break;
  case "wbmp":
    $mime = "image/vnd.wap.wbmp"; 
    break; 
  case "wmlc":
    $mime = "application/vnd.wap.wmlc";
    break;
  case "mp4s": 
    $mime = "application/mp4";
    break;
  case "ogg": 
    $mime = "application/ogg"; 
    break; 
  case "pls":
    $mime = "application/pls+xml"; 
    break;
  case "asf": 
    $mime = "application/vnd.ms-asf";
    break;
  case "swf":
    $mime = "application/x-shockwave-flash";
    break;
  case "mp4": 
    $mime = "video/mp4";
    break; 
  case "m4a": 
    $mime = "audio/mp4"; 
    break; 
  case "m4p": 
    $mime = "audio/mp4"; 
    break;
  case "mp4a":
    $mime = "audio/mp4"; 
    break; 
  case "mp3": 
    $mime = "audio/mpeg"; 
    break; 
  case "m3a":
    $mime = "audio/mpeg"; 
    break; 
  case "m2a":
    $mime = "audio/mpeg"; 
    break; 
  case "mp2a": 
    $mime = "audio/mpeg"; 
    break; 
  case "mp2":
    $mime = "audio/mpeg"; 
    break; 
  case "mpga": 
    $mime = "audio/mpeg"; 
    break;
  case "wav":
    $mime = "audio/wav";
    break;
  case "m3u":
    $mime = "audio/x-mpegurl"; 
    break;
  case "bmp": 
    $mime = "image/bmp"; 
    break;
  case "ico":
    $mime = "image/x-icon"; 
    break;
  case "3gp":
    $mime = "video/3gpp"; 
    break;
  case "3g2": 
    $mime = "video/3gpp2"; 
    break;
  case "mp4v":
    $mime = "video/mp4"; 
    break; 
  case "mpg4": 
    $mime = "video/mp4"; 
    break; 
  case "m2v": 
    $mime = "video/mpeg"; 
    break; 
  case "m1v": 
    $mime = "video/mpeg"; 
    break; 
  case "mpe": 
    $mime = "video/mpeg"; 
    break; 
  case "mpeg":
    $mime = "video/mpeg"; 
    break;
  case "mpg": 
    $mime = "video/mpeg"; 
    break; 
  case "mov":
    $mime = "video/quicktime"; 
    break; 
  case "qt": 
    $mime = "video/quicktime";
    break; 
  case "avi":
    $mime = "video/x-msvideo";
  break; case "midi": 
    $mime = "audio/midi"; 
    break;
  case "mid": 
    $mime = "audio/mid"; 
    break;
  case "amr":
    $mime = "audio/amr";
    break;
  default: 
    $mime = "application/force-download";
} 

header('Content-Description: File Transfer'); 
header('Content-Type: '.$mime);
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary'); header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
header('Pragma: public'); header('Content-Length: ' . filesize($file));
ob_clean(); 
flush(); 
readfile($file); 
}