PHP mkdir Function

last modified April 3, 2025

The PHP mkdir function creates a new directory with specified permissions. It's essential for filesystem operations in PHP applications.

Basic Definition

The mkdir function attempts to create the directory specified by pathname. It returns true on success or false on failure.

Syntax: mkdir(string $directory, int $permissions = 0777, bool $recursive = false, resource $context = null): bool. The function supports recursive directory creation.

Basic mkdir Example

This shows the simplest usage of mkdir to create a single directory.

basic_mkdir.php

<?php

declare(strict_types=1);

$dir = "new_directory";

if (mkdir($dir)) {
    echo "Directory created successfully";
} else {
    echo "Failed to create directory";
}

This creates "new_directory" in the current working directory. The default permissions (0777) are used if not specified.

Specifying Permissions

You can set specific permissions when creating a directory.

mkdir_permissions.php

<?php

declare(strict_types=1);

$dir = "secure_dir";
$permissions = 0750; // Owner: rwx, Group: r-x, Others: ---

if (mkdir($dir, $permissions)) {
    echo "Secure directory created";
} else {
    echo "Directory creation failed";
}

This creates a directory with restricted permissions. Note that the actual permissions may be affected by the umask setting.

Recursive Directory Creation

The recursive parameter allows creating nested directories in one call.

recursive_mkdir.php

<?php

declare(strict_types=1);

$path = "parent/child/grandchild";

if (mkdir($path, 0777, true)) {
    echo "Directory tree created";
} else {
    echo "Failed to create directories";
}

This creates all three directories (parent, child, grandchild) if they don't exist. Without recursive mode, this would fail if parent didn't exist.

Checking Directory Existence

It's good practice to check if a directory exists before creating it.

mkdir_exists.php

<?php

declare(strict_types=1);

$dir = "new_folder";

if (!file_exists($dir)) {
    if (mkdir($dir)) {
        echo "Directory created";
    } else {
        echo "Creation failed";
    }
} else {
    echo "Directory already exists";
}

This prevents errors when trying to create an existing directory. The file_exists check is important for robust code.

Using Context Parameter

The context parameter allows specifying stream context options.

mkdir_context.php

<?php

declare(strict_types=1);

$dir = "context_dir";
$context = stream_context_create();

if (mkdir($dir, 0777, false, $context)) {
    echo "Directory created with context";
} else {
    echo "Context creation failed";
}

This shows the basic usage of context, though normally you'd set specific stream options. Context is rarely needed for local filesystem operations.

Best Practices

Error Handling: Always check the return value of mkdir.
Permissions: Set appropriate permissions for security.
Exists Check: Verify if directory exists first.
Recursive: Use recursive mode for nested directories.
Absolute Paths: Prefer absolute paths for reliability.

Source

PHP mkdir Documentation

This tutorial covered the PHP mkdir function with practical examples showing directory creation in different scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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