使用 PHP 删除空子文件夹

2022-01-01 00:00:00 directory php

我正在开发一个 PHP 函数，该函数将递归删除所有不包含从给定绝对路径开始的文件的子文件夹.

I am working on a PHP function that will recursively remove all sub-folders that contain no files starting from a given absolute path.

这是目前开发的代码:

function RemoveEmptySubFolders($starting_from_path) {

    // Returns true if the folder contains no files
    function IsEmptyFolder($folder) {
        return (count(array_diff(glob($folder.DIRECTORY_SEPARATOR."*"), Array(".", ".."))) == 0);
    }

    // Cycles thorugh the subfolders of $from_path and
    // returns true if at least one empty folder has been removed
    function DoRemoveEmptyFolders($from_path) {
        if(IsEmptyFolder($from_path)) {
            rmdir($from_path);
            return true;
        }
        else {
            $Dirs = glob($from_path.DIRECTORY_SEPARATOR."*", GLOB_ONLYDIR);
            $ret = false;
            foreach($Dirs as $path) {
                $res = DoRemoveEmptyFolders($path);
                $ret = $ret ? $ret : $res;
            }
            return $ret;
        }
    }

    while (DoRemoveEmptyFolders($starting_from_path)) {}
}

根据我的测试，此功能有效，但我很高兴看到任何改进代码性能的想法.

As per my tests this function works, though I would be very delighted to see any ideas for better performing code.

推荐答案

如果您在空文件夹内有空文件夹内有空文件夹，则需要在所有文件夹中循环 3 次.所有这一切，因为您首先要进行广度测试 - 在测试其子项之前测试文件夹.相反，您应该在测试父文件夹是否为空之前进入子文件夹，这样一次就足够了.

If you have empty folder within empty folder within empty folder, you'll need to loop through ALL folders three times. All this, because you go breadth first - test folder BEFORE testing its children. Instead, you should go into child folders before testing if parent is empty, this way one pass will be sufficient.

function RemoveEmptySubFolders($path)
{
  $empty=true;
  foreach (glob($path.DIRECTORY_SEPARATOR."*") as $file)
  {
     if (is_dir($file))
     {
        if (!RemoveEmptySubFolders($file)) $empty=false;
     }
     else
     {
        $empty=false;
     }
  }
  if ($empty) rmdir($path);
  return $empty;
}

顺便说一下， glob 不会返回.和...条目.

By the way, glob does not return . and .. entries.

更短的版本:

function RemoveEmptySubFolders($path)
{
  $empty=true;
  foreach (glob($path.DIRECTORY_SEPARATOR."*") as $file)
  {
     $empty &= is_dir($file) && RemoveEmptySubFolders($file);
  }
  return $empty && rmdir($path);
}

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