php 求两个文件的相对路径

$a = ‘/a/b/c/d/e.php‘;

$b = ‘/a/d/12/34/c.php‘;

getpath($a , $b );
  
public function getpath($a, $b)
{
     $aarr = explode(‘/‘, $a);
     $barr = explode(‘/‘, $b);
     $count = count($barr) - 2;
     $pathinfo = ‘‘;
     for($i = 1; $i <= $count; $i++){
         if($aarr[$i] == $barr[$i]){
              $pathinfo .= ‘../‘;
         }else{
              $pathinfo .= $barr[$i] . ‘/‘;
         }
     }
     echo $pathinfo;
}

    function getpath($a,$b)
    {
         $aarr = explode(‘/‘, $a);
         $barr = explode(‘/‘, $b);
         $flag = true; 
         $count = count($barr) - 2;
         $pathinfo = ‘‘;
         for($i = 1; $i <= $count; $i++){
             if($flag && $aarr[$i] != $barr[$i] ){
                  $pathinfo .= str_repeat(‘../‘, $count-$i+1).$aarr[$i].‘/‘;
                  $flag = false;
              }elseif(!$flag){
                    $pathinfo .= $aarr[$i].‘/‘;
              }
         }
         return empty($pathinfo)? ‘./‘ : $pathinfo;
    }

    echo getpath($a,$b);