以下代码来自http://php.net/unlink:

/**
 * Delete a file or recursively delete a directory
 *
 * @param string $str Path to file or directory
 */
function recursiveDelete($str) {
    if (is_file($str)) {
        return @unlink($str);
    }
    elseif (is_dir($str)) {
        $scan = glob(rtrim($str,'/').'/*');
        foreach($scan as $index=>$path) {
            recursiveDelete($path);
        }
        return @rmdir($str);
    }
}

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());
    }
}

另一个解决方案: 该类删除所有文件、子目录和子目录中的文件。

class Your_Class_Name {
    /**
     * @see http://php.net/manual/de/function.array-map.php
     * @see http://www.php.net/manual/en/function.rmdir.php 
     * @see http://www.php.net/manual/en/function.glob.php
     * @see http://php.net/manual/de/function.unlink.php
     * @param string $path
     */
    public function delete($path) {
        if (is_dir($path)) {
            array_map(function($value) {
                $this->delete($value);
                rmdir($value);
            },glob($path . '/*', GLOB_ONLYDIR));
            array_map('unlink', glob($path."/*"));
        }
    }
}

我更新了@Stichoza的答案，通过子文件夹删除文件。

function glob_recursive($pattern, $flags = 0) {
    $fileList = glob($pattern, $flags);
    foreach (glob(dirname($pattern).'/*', GLOB_ONLYDIR|GLOB_NOSORT) as $dir) {
        $subPattern = $dir.'/'.basename($pattern);
        $subFileList = glob_recursive($subPattern, $flags);
        $fileList = array_merge($fileList, $subFileList);
    }
    return $fileList;
}

function glob_recursive_unlink($pattern, $flags = 0) {
    array_map('unlink', glob_recursive($pattern, $flags));
}

以下代码来自http://php.net/unlink:

/**
 * Delete a file or recursively delete a directory
 *
 * @param string $str Path to file or directory
 */
function recursiveDelete($str) {
    if (is_file($str)) {
        return @unlink($str);
    }
    elseif (is_dir($str)) {
        $scan = glob(rtrim($str,'/').'/*');
        foreach($scan as $index=>$path) {
            recursiveDelete($path);
        }
        return @rmdir($str);
    }
}