brainf**k of the last 15 minutes! =)

checkConfigSyntax.php

<?php
if(preg_match("/^; <\?php die\(\); \?>".PHP_EOL."([\w\d]+=[#$\w\d\/\"\\\]+".PHP_EOL.")*(\[[\w\d]+\]".PHP_EOL."([\w\d]+=[#$\w\d\/\"\\\]+".PHP_EOL.")*)*\$/im", @file_get_contents('conf.php') )){
echo ("match");
}
else{
echo ("didn't match");}
?>

conf.php

; <?php die(); ?>
fo_o="_b\/a#$är"
[general]
foo="b\/aär"
t=123
t2=123
[foo]
bar="foobar"