Example of preg_match

admin.php

<?php
/* test regex */

$input[] = 'admin/';
$input[] = 'mens-books';
$input[] = 'admin/foo';
$input[] = 'foo/bar';
$input[] = 'min';
$input[] = 'admin';

$regex = '/^(?!admin\/)/';

foreach ($input as $in) {
  echo $in . ' - ';
  if(preg_match($regex, $in)) {
    echo 'Match';
  }
  else {
    echo 'No Match';
  }
  echo "\n";
}