<?php
function bbcode($data)
{
'/\[b\](.*?)\[\/b\]/is',
'/\[b\](.*?)$/',
);
'<b>$1</b>',
'<b>$1</b>',
);
}
$bcode = bbcode('[b]this is testing text');
echo $bcode;
PD9waHAKCWZ1bmN0aW9uIGJiY29kZSgkZGF0YSkKCXsKCQkkaW5wdXQgPSBhcnJheSgKCQkJJy9cW2JcXSguKj8pXFtcL2JcXS9pcycsCgkJCScvXFtiXF0oLio/KSQvJywKCQkpOwoJCSRvdXRwdXQgPSBhcnJheSgKCQkJJzxiPiQxPC9iPicsCgkJCSc8Yj4kMTwvYj4nLAoJCSk7CgkJcmV0dXJuIHByZWdfcmVwbGFjZSAoJGlucHV0LCAkb3V0cHV0LCAkZGF0YSk7OwogICAgfQoKJGJjb2RlID0gYmJjb2RlKCdbYl10aGlzIGlzIHRlc3RpbmcgdGV4dCcpOwplY2hvICRiY29kZTs=