怎么从参数文件中读取内容并替换变量值

$a1 = '02';<br />$a2 = '01';<br />$a3 = '03';<br /><br />$c1 = '01';<br />$c2 = '03';<br />$c3 = '05';<br /><br />$na = 'a';<br />parse_str(str_replace(array(':', PHP_EOL), array('=', '&'), file_get_contents("data/$na.txt")), $ar);<br />foreach(preg_grep("/^$na\d+/", array_keys(get_defined_vars())) as $v) {<br />  $$v = $ar[$$v];<br />}<br />$na = 'c';<br />parse_str(str_replace(array(':', PHP_EOL), array('=', '&'), file_get_contents("data/$na.txt")), $ar);<br />foreach(preg_grep("/^$na\d+/", array_keys(get_defined_vars())) as $v) {<br />  $$v = $ar[$$v];<br />}<br />echo $a1, PHP_EOL;<br />echo $a2, PHP_EOL;<br />echo $a3, PHP_EOL;<br />echo $c1, PHP_EOL;<br />echo $c2, PHP_EOL;<br />echo $c3, PHP_EOL;<br />