PHP Script to Force Download a file using Header Function

This PHP script that will make the browser to open a new window and download a file instead of opening it. This script is helpful if you dont want a file to be open directly when using a browser, like if you want a javascript or simple text file to be downloaded.

function file_ext( $pathInfo, $type ){
	$res = pathinfo($pathInfo);
	return $res[$type];
}

function mime_type($filename){
	
	/* get the file extension of a file name */
	$extension = file_ext( $filename, 'extension' );

	switch(strtolower($extension)){
		case "js" :
			return "application/x-javascript";
			break;
		case "json" :
			return "application/json";
			break;
		case "jpg" :
		case "jpeg" :
		case "jpe" :
			return "image/jpg";
			break;
		case "png" :
		case "gif" :
		case "bmp" :
		case "tiff" :
			return "image/".strtolower($extension);
			break;
		case "css" :
			return "text/css";
			break;
		case "xml" :
			return "application/xml";
			break;
		case "doc" :
		case "docx" :
			return "application/msword";
			break;
		case "xls" :
		case "xlt" :
		case "xlm" :
		case "xld" :
		case "xla" :
		case "xlc" :
		case "xlw" :
		case "xll" :
			return "application/vnd.ms-excel";
			break;
		case "ppt" :
		case "pps" :
			return "application/vnd.ms-powerpoint";
			break;
		case "rtf" :
			return "application/rtf";
			break;
		case "pdf" :
			return "application/pdf";
			break;
		case "html" :
		case "htm" :
		case "php" :
			return "text/html";
		case "txt" :
			return "text/plain";
			break;
		case "mpeg" :
		case "mpg" :
		case "mpe" :
			return "video/mpeg";
			break;
		case "mp3" :
			return "audio/mpeg3";
			break;
		case "wav" :
			return "audio/wav";
			break;
		case "aiff" :
		case "aif" :
			return "audio/aiff";
			break;
		case "avi" :
			return "video/msvideo";
			break;
		case "wmv" :
			return "video/x-ms-wmv";
			break;
		case "mov" :
			return "video/quicktime";
			break;
		case "zip" :
			return "application/zip";
			break;
		case "tar" :
			return "application/x-tar";
			break;
		case "swf" :
			return "application/x-shockwave-flash";
			break;
		default :
			return "application/octet-stream";
			break;
	}
}


/* 
Get the value of the variable file_name GET
value of variable file_name will then be decode 
from its URL format and also decode from its 
base64 encoding.
*/
$file_name = base64_decode(urldecode($_GET['file_name']));
	
/* return the MIME Type of the File */
$content_type = mime_type($file_name);

/* Change to file the directory location of the file */
$file_root_loc = 'public_html/uploads/';

header('Content-type: '.$content_type);
header('Content-Disposition: attachment; filename="'.$file_name.'"');
readfile($file_root_loc.$file_name);