Base 64 URL encoding/decoding sample

base64_sample.php

<?php

//Checks if plain URL was given
if ( $_GET['url'] ){
  //Encodes $_GET['url'] parameter
  $encodedURL = base64_encode( urlencode( $_GET['url'] ) );

  //Prints out the encoded url
  echo "Encoded URL => " . $encodedURL . "<br />";
}
//Checks if encoded URL was given
else if ( $_GET['enc'] ) {
  //Decodes $_GET['enc'] parameter
  $decodedURL = urldecode( base64_decode( $_GET['enc'] ) );

  //Prints out the decoded url
  echo "Decoded URL => " . $decodedURL . "<br />";
}
//If no encoded or decoded URL, prints a simple help
else {
  ?>
  <h1> Error! </h1>
  <p>You should inform either an URL to encode or and encoded URL to decode.</p>
  <p>Use ?url=http://example.com to encode the given URL.</p>
  <p>Use ?enc= to decode the given encoded URL.</p>
  <?php
}