$re = '/int\s+.*? (
\{ # Match opening brace
(?: # Start non-capturing group
[^{}]++ # Match non-brace chars without backtracking
| # OR
(?-1) # Recursively match the entire expression
)* # Match 0 or more times
\}
)/xs';
$str = 'int max(int x, int y)
{
if (x > y)
{
return x;
}
else
{
return y;
}
}';
preg_match_all($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