$re = '/\~\![A-Za-z]+\ start(?:(?:(?:\(|,)\ ?[\w]+)*?\))\:\{((?:(?!\}\:end\n)[\S\s])+)(?:\}\:end)/';
$str = '~!data start(f1, f2, f3):{
abc \'\\}:end\'a
}:end
~!data start(f1, f2, f3):{
abc \'\\}:end\'a
}:end';
preg_match_all($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