Adding download option to images - php

Question

I have a PHP script that is working fine for displaying all my images in a directy that I upload to. I wand to make a little download button so someone can click the button and download the image. I am making this for my company so people can download our logos.
<?php
// Find all files in that folder
$files = glob('grips/*');
// Do a natural case insensitive sort, usually 1.jpg and 10.jpg would come next to each other with a regular sort
natcasesort($files);
// Display images
foreach($files as $file) {
echo '<img src="' . $file . '" />';
}
?>
I figue I could just make a button and call the href of $file but that would just link to the file and show the image. I am not sure to have it auto download. Any help would be great.

Answer 1

Just add some headers in a download.php file so you can then read the file in like this:
Make sure you sanitize your data coming to the file, you don't want people to be able to download your php files.
<?php
// Find all files in that folder
$files = glob('grips/*');
// Do a natural case insensitive sort, usually 1.jpg and 10.jpg would come next to each other with a regular sort
natcasesort($files);
// Display images
foreach($files as $file) {
echo '<img src="' . $file . '" /><br />Download Image';
}
?>
download.php
$filename = base64_decode($_GET["file"]);
// Data sanitization goes here
if(!getimagesize($filename) || !is_file($filename)){
// Not an image, or file doesn't exist. Redirect user
header("Location: /back_to_images.php");
exit;
}
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Disposition: attachment; filename=".basename($filename).";");
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".filesize($filename));
readfile($filename);