- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
// Everything you enter here will be executed by our servers. Try it!
$p = '/^([A-Za-z0-9\!\@\#\$\%\^\&\*\(\)\-\=\_\+\~\`\\\'\;\[\]\/\.\,\<\>\?\|\"\:\}\{])*$/';
var_dump(
preg_match($p, 'admin')
);