$re = '/(?:[^@`]|\s+|^)(?:love|luv)\s?(?:u|you|me)?,?\s?(?:cbot|@?camperbot)/i';
$str = 'Show me some
# Should
Show me some luv cbot
Do you love me cbot?
love cbot
love camperbot
luv you, cbot
We love u @camperbot
love you cbot
love, cbot
`
love camperbot
`
# Shouldn\'t
noone loves, cbot
`love camperbot`
@love you cbot
I love js
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php