<?php
$regex1 = '/^(|(\[[^\]]*\])|([A-Z][A-Z0-9_\-]*\s*=(\s*(("[^"]*")|(_QQ_)))+))\s*(;.*)?$/';
$regex2 = '/^(|(\[[^\]]*\])|([A-Z][A-Z0-9_\-]*\s*=(\s*(("(\"|[^"])*")|(_QQ_)))+))\s*(;.*)?$/';
$line1 = 'JLIB_LOGIN_AUTHENTICATE="Username and password do not match or you do not have an account yet."';
$line2 = 'JLIB_LOGIN_AUTHENTICATE="foo \" bar"; baz';
 
echo preg_match($regex1, $line1) . "\n";
echo preg_match($regex1, $line2) . "\n";
echo preg_match($regex2, $line1) . "\n";
echo preg_match($regex2, $line2) . "\n";
?>

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