<?
//delete all files from folder  & sub folders
function listFolderFiles($dir)
{
    $ffs = scandir($dir);
    echo '<ol>';
    foreach ($ffs as $ff) {
        if ($ff != '.' && $ff != '..') {
            if (file_exists("$dir/$ff")) {
                unlink("$dir/$ff");
            }
            echo '<li>' . $ff;
            if (is_dir($dir . '/' . $ff)) {
                listFolderFiles($dir . '/' . $ff);
            }
            echo '</li>';
        }
    }
    echo '</ol>';
}
$arr = array(
    "folder1",
    "folder2"
);
for ($x = 0; $x < count($arr); $x++) {
    $mm = $arr[$x];
    listFolderFiles($mm);
}
//end
?> 

下面是一种使用标准PHP库(SPL)的更现代的方法。

$dir = "path/to/directory";
if(file_exists($dir)){
    $di = new RecursiveDirectoryIterator($dir, FilesystemIterator::SKIP_DOTS);
    $ri = new RecursiveIteratorIterator($di, RecursiveIteratorIterator::CHILD_FIRST);
    foreach ( $ri as $file ) {
        $file->isDir() ?  rmdir($file) : unlink($file);
    }
}

参见readdir和unlink。

<?php
    if ($handle = opendir('/path/to/files'))
    {
        echo "Directory handle: $handle\n";
        echo "Files:\n";

        while (false !== ($file = readdir($handle)))
        {
            if( is_file($file) )
            {
                unlink($file);
            }
        }
        closedir($handle);
    }
?>

foreach (new DirectoryIterator('/path/to/directory') as $fileInfo) {
    if(!$fileInfo->isDot()) {
        unlink($fileInfo->getPathname());
    }
}

如果你想删除文件夹中的所有内容(包括子文件夹)，请使用array_map, unlink和glob的组合:

array_map( 'unlink', array_filter((array) glob("path/to/temp/*") ) );

这个调用还可以处理空目录(感谢您的提示，@mojuba!)

 <?
//delete all files from folder  & sub folders
function listFolderFiles($dir)
{
    $ffs = scandir($dir);
    echo '<ol>';
    foreach ($ffs as $ff) {
        if ($ff != '.' && $ff != '..') {
            if (file_exists("$dir/$ff")) {
                unlink("$dir/$ff");
            }
            echo '<li>' . $ff;
            if (is_dir($dir . '/' . $ff)) {
                listFolderFiles($dir . '/' . $ff);
            }
            echo '</li>';
        }
    }
    echo '</ol>';
}
$arr = array(
    "folder1",
    "folder2"
);
for ($x = 0; $x < count($arr); $x++) {
    $mm = $arr[$x];
    listFolderFiles($mm);
}
//end
?>