Preview last screenshot on another device

retina-preview.php

<?php 

/* I use this to quickly preview last taken screenshot on my retina ipad.
 * (I use xip.io to quickly access virtual hosts on my dev machine.)
 * 
 * Be sure to allow write in the dir where this script is located.
 * 
 * It's possible to change the directory where screenshots are stored on mac. 
 * Consider using one exclusively for this purpose
 * (see google.com/search?q=change+screenshot+location+mac).
 */

$pixelRatio = 2; // to preview pics on @2x retina screen
$dir = '/Users/username/Documents/Screenshots'; // allow server to read this dir

// find file
$files = glob($dir . "/*.png");
$files = array_combine($files, array_map("filemtime", $files));
arsort($files);
$latest = key($files);
copy($latest, 'img.png');

// set img size
$size = getimagesize($latest);
$width = $size[0] / $pixelRatio;
$height = $size[1] / $pixelRatio;

echo "<img src=\"img.png\" width=\"$width\" height=\"$height\">";