$re = '/^(‾+|(‾*\\\\)?(_*\/‾*\\\\)*_*(\/‾*)?)$/m';
$str = '__/‾‾\\/\\_/‾
1
_
1
\\
1
/
1
‾
1
___
1
\\/
1
/\\/
1
/\\/\\
1
‾‾‾
1
\\\\
0
‾‾
1
_‾
0
‾_
0
\\_____/
1
\\/\\\\/\\\\___
0
\\/\\__/‾‾\\
1
______/\\_____
1
‾‾‾‾‾‾\\\\_____
0
‾‾‾‾‾‾\\______
1
_____/‾‾‾‾‾
1
\\___/‾‾‾\\___/‾‾‾
1
\\_/_\\_
0
\\_/\\_
1
/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/
1
____________________
1
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
1
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾/
0
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾\\
1
/\\‾/\\‾___/|\\_|\\/__\\/\\‾‾
0';
preg_match_all($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