如何通过PHP检查目录是否存在?

I want to create a directory if it does'nt exist.

如果目录不存在，我想创建它。

Is using is_dir enough for that purpose?

使用is_dir足以达到这个目的吗?

if (!is_dir($dir)) {
    mkdir($dir);         
}

Or should I combine is_dir with file_exists?

还是应该将is_dir与file_exist合并?

if (!file_exists($dir) && !is_dir($dir)) {
    mkdir($dir);         
} 

8 个解决方案

#1

Both would return true on Unix systems - in Unix everything is a file, including directories. But to test if that name is taken, you should check both. There might be a regular file named 'foo', which would prevent you from creating a directory name 'foo'.

两者在Unix系统上都将返回true—在Unix系统中，所有内容都是一个文件，包括目录。但是要测试这个名字是否被使用，您应该同时检查这两个名称。可能有一个名为“foo”的常规文件，它会阻止您创建一个目录名“foo”。

#2

$dirname = $_POST["search"];
$filename = "/folder/" . $dirname . "/";

if (!file_exists($filename)) {
    mkdir("folder/" . $dirname, 0777);
    echo "The directory $dirname was successfully created.";
    exit;
} else {
    echo "The directory $dirname exists.";
}

#3

I think realpath() may be the best way to validate if a path exist http://www.php.net/realpath

我认为realpath()可能是验证路径是否存在的最佳方法http://www.php.net/realpath

Here is an example function:

下面是一个示例函数:

<?php
/**
 * Checks if a folder exist and return canonicalized absolute pathname (long version)
 * @param string $folder the path being checked.
 * @return mixed returns the canonicalized absolute pathname on success otherwise FALSE is returned
 */
function folder_exist($folder)
{
    // Get canonicalized absolute pathname
    $path = realpath($folder);

    // If it exist, check if it's a directory
    if($path !== false AND is_dir($path))
    {
        // Return canonicalized absolute pathname
        return $path;
    }

    // Path/folder does not exist
    return false;
}

Short version of the same function

同一函数的简短版本

<?php
/**
 * Checks if a folder exist and return canonicalized absolute pathname (sort version)
 * @param string $folder the path being checked.
 * @return mixed returns the canonicalized absolute pathname on success otherwise FALSE is returned
 */
function folder_exist($folder)
{
    // Get canonicalized absolute pathname
    $path = realpath($folder);

    // If it exist, check if it's a directory
    return ($path !== false AND is_dir($path)) ? $path : false;
}

Output examples

输出示例

<?php
/** CASE 1 **/
$input = '/some/path/which/does/not/exist';
var_dump($input);               // string(31) "/some/path/which/does/not/exist"
$output = folder_exist($input);
var_dump($output);              // bool(false)

/** CASE 2 **/
$input = '/home';
var_dump($input);
$output = folder_exist($input);         // string(5) "/home"
var_dump($output);              // string(5) "/home"

/** CASE 3 **/
$input = '/home/..';
var_dump($input);               // string(8) "/home/.."
$output = folder_exist($input);
var_dump($output);              // string(1) "/"

Usage

使用

<?php

$folder = '/foo/bar';

if(FALSE !== ($path = folder_exist($folder)))
{
    die('Folder ' . $path . ' already exist');
}

mkdir($folder);
// Continue do stuff

#4

Second variant in question post is not ok, because, if you already have file with the same name, but it is not a directory, !file_exists($dir) will return false, folder will not be created, so error "failed to open stream: No such file or directory" will be occured. In Windows there is a difference between 'file' and 'folder' types, so need to use file_exists() and is_dir() at the same time, for ex.:

问题中的第二个变体是不可以的，因为，如果您已经有同名的文件，但是它不是一个目录，!file_exists($dir)将返回false，文件夹将不会被创建，因此错误“未能打开流:没有这样的文件或目录”将被占用。在Windows中，“文件”和“文件夹”类型之间有区别，因此需要同时使用file_exists()和is_dir()，例如:

if (file_exists('file')) {
    if (!is_dir('file')) { //if file is already present, but it's not a dir
        //do something with file - delete, rename, etc.
        unlink('file'); //for example
        mkdir('file', NEEDED_ACCESS_LEVEL);
    }
} else { //no file exists with this name
    mkdir('file', NEEDED_ACCESS_LEVEL);
}

#5

$year = date("Y");   
$month = date("m");   
$filename = "../".$year;   
$filename2 = "../".$year."/".$month;

if(file_exists($filename)){
    if(file_exists($filename2)==false){
        mkdir($filename2,0777);
    }
}else{
    mkdir($filename,0777);
}

#6

$save_folder = "some/path/" . date('dmy');

if (!file_exists($save_folder)) {
   mkdir($save_folder, 0777);
}

#7

Well instead of checking both, you could do if(stream_resolve_include_path($folder)!==false). It is slower but kills two birds in one shot.

但是，如果(stream_resolve_include_path($文件夹)!==false)，那么您可以这样做。它速度较慢，但一次就能杀死两只鸟。

Another option is to simply ignore the E_WARNING, not by using @mkdir(...); (because that would simply waive all possible warnings, not just the directory already exists one), but by registering a specific error handler before doing it:

另一种选择是忽略E_WARNING，而不是使用@mkdir(…);(因为这样做只会放弃所有可能的警告，而不只是目录已经存在)，而是在执行之前注册一个特定的错误处理程序:

namespace com\*;

set_error_handler(function($errno, $errm) { 
    if (strpos($errm,"exists") === false) throw new \Exception($errm); //or better: create your own FolderCreationException class
});
mkdir($folder);
/* possibly more mkdir instructions, which is when this becomes useful */
restore_error_handler();

#8

add true after 0777

0777年之后添加真实

<?php
    $dirname = "small";
    $filename = "upload/".$dirname."/";

    if (!is_dir($filename )) {
        mkdir("upload/" . $dirname, 0777, true);
        echo "The directory $dirname was successfully created.";
        exit;
    } else {
        echo "The directory $dirname exists.";
    }
     ?>