db.php

<?php

if ($_SERVER['SCRIPT_NAME'] === '/db.php') {
   $error = "silly geezer went to db.php";
   $error_encoded = trim(base64_encode($error), '=');
   error_log("Gave SWR error: " . $error);
   header("Location: /swr?id=" . $error_encoded);
   die();
}

// Enter your host name, database username, password, and database name.
// If you have not set database password on localhost then set empty.
$con = mysqli_connect(
   "localhost",
   "phpmysql",
   "j%XNr&P'j!#~89@",
   "englon"
);

// Check connection
if (mysqli_connect_errno()) {
   echo "Failed to connect to MySQL: " . mysqli_connect_error();
   $error = 'Failed to connect to the MySQL database englon: ' . mysqli_connect_error();
   error_log("Gave SWR error: " . $error);
   header("Location: /swr?id=" . base64_encode($error));
}

/**
 * Optimizes PNG file with pngquant 1.8 or later (reduces file size of 24-bit/32-bit PNG images).
 *
 * BUZZZZ
 *
 * @param $path_to_png_file string - path to any PNG file, e.g. $_FILE['file']['tmp_name']
 * @param $max_quality int - conversion quality, useful values from 60 to 100 (smaller number = smaller file)
 * @return string - content of PNG file after conversion
 */
function compress_png($path_to_png_file, $max_quality = 90)
{
   if (!file_exists($path_to_png_file)) {
      throw new Exception("File does not exist: $path_to_png_file");
   }

   // guarantee that quality won't be worse than that.
   $min_quality = 60;

   // '-' makes it use stdout, required to save to $compressed_png_content variable
   // '<' makes it read from the given file path
   // escapeshellarg() makes this safe to use with any path
   $compressed_png_content = shell_exec("pngquant --quality=$min_quality-$max_quality - < " . escapeshellarg($path_to_png_file));

   if (!$compressed_png_content) {
      throw new Exception("Conversion to compressed PNG failed. Is pngquant 1.8+ installed on the server?");
   }

   return $compressed_png_content;
}
?>