Download files to a remote server.

download.php

<?php

if (isset($_POST['url'])) {
  if (empty($_POST['filename'])) {
    $filename = 'download.bin';
  }
  else {
    $filename = $_POST['filename'];
  }
  
  # Credits: http://stackoverflow.com/a/3938551/1149962
  file_put_contents($filename, $url);
  exit('Done.');
}

?>
<form method="POST">
  <label>
    <span>URL: </span>
    <input type="text" name="url">
  </label>
  <label>
    <span>Filename: </span>
    <input type="text" name="filename">
  </label>
  <input type="submit" value="Submit">
</form>