php调用系统命令执行批处理文件

<?php
header("Content-Type: text/html; charset=gb2312");
function my_exec($cmd, $input="")
{
       $proc=proc_open($cmd, array(0=>array("pipe", "r"),
                          1=>array("pipe", "w"),
                          2=>array("pipe",  "w")),
                          $pipes);
      fwrite($pipes[0], $input); fclose($pipes[0]);
       $stdout=stream_get_contents($pipes[1]); fclose($pipes[1]);    
      $stderr=stream_get_contents($pipes[2]); fclose($pipes[2]);
       $rtn=proc_close($proc); return array( "stdout"=>$stdout,
                                     "stderr"=>$stderr,
                                "return"=>$rtn );
}
      $need_run_file = __DIR__."..1make.bat";
      $need_run_file = "D:xampphtdocswu1make.bat";
      var_export(my_exec($need_run_file)); 
?>