$re = '/(?<=[?!#])[\w\W]*?(?=;)/m';
$str = '#first line of text;
#second line of text;
#third line could easy
be on a new line;
#forth etc;
#this could (#hi,#hi,#hi) also
happen though:));
#so.... any idea;';
preg_match_all($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