<?php
$re = "/modules\\\\([^\\\\]*)\\\\controllers/";
$str = "test\\modules\\test\\controllers";
echo $matches[1];
PD9waHAKCiRyZSA9ICIvbW9kdWxlc1xcXFwoW15cXFxcXSopXFxcXGNvbnRyb2xsZXJzLyI7IAokc3RyID0gInRlc3RcXG1vZHVsZXNcXHRlc3RcXGNvbnRyb2xsZXJzIjsgCnByZWdfbWF0Y2goJHJlLCAkc3RyLCAkbWF0Y2hlcyk7CmVjaG8gJG1hdGNoZXNbMV07