$re = '/(?<=\[)([^[]*)(?=\|)\|\1(?=\])/m';
$str = '==///Listings==/?
assadsadsadsa
adasdsad
</test>
\'\'[[excellent wheat|excellent wheat]]\'\'
\'\'[[brilliant corn|Tom\'s brilliant corn]]\'\'
</separation>
Remember to purchase this if on offer
\'\'[[jub|jub/ha]]\'\',
\'\'[[barley|barley/hops]]\'\'
zcxcxzcxz';
preg_match_all($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