$re = '/_([^\s]+)(?=.)/';
$str = '@VAR;Variable=Speed;Value=Fast;Op==;@ENDVAR;
@VAR;Variable=Fabricator;Value=Freescale;Op==;@ENDVAR;
@VAR; @ENDVAR;
@VAR;@ENDVAR;';
preg_match_all($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