When working with PHP, mkdir can help with a specific task: creates a directory, optionally creating intermediate directories recursively.
This guide shows what mkdir does, how to use it in code, and which details you should check before relying on the result.
What Is mkdir in PHP?
Creates a directory, optionally creating intermediate directories recursively.
Usage: The following examples show calls with suitable values. Consult the function parameters described in the examples, especially when optional arguments or extensions are involved.
Example 1: Basic Usage
The first example introduces mkdir with a direct PHP expression.
<?php
$path = sys_get_temp_dir() . "/php-guide-" . bin2hex(random_bytes(4)); echo mkdir($path) ? "Created" : "Failed"; rmdir($path);
Observe the value returned or printed by mkdir and compare it with the input used in this example.
Example 2: A Different Input or Option
This second example demonstrates another input or condition, so you can compare the behavior with the first example.
<?php
$base = sys_get_temp_dir() . "/php-guide-" . bin2hex(random_bytes(4)); mkdir($base . "/reports", 0775, true); echo is_dir($base . "/reports") ? "Exists" : "Missing"; rmdir($base . "/reports"); rmdir($base);
Observe the value returned or printed by mkdir and compare it with the input used in this example.
Practical Example
Here is a small scenario illustrating how mkdir can fit into application code. Run the example only in an appropriate development environment if it reads files, changes data, starts processes or connects to a service.
<?php
$directory = sys_get_temp_dir() . "/export-" . bin2hex(random_bytes(4)); if (!is_dir($directory) && mkdir($directory, 0775, true)) { echo "Export directory ready"; rmdir($directory); }
Observe the value returned or printed by mkdir and compare it with the input used in this example.
Important Behavior and Edge Cases
- Core behavior: Creates a directory, optionally creating intermediate directories recursively.
- Important limitation: Directory permissions are affected by umask; beware of race conditions when handling user-supplied paths.
- Production use: Check return values and handle failures before acting on the result.
Comparison With Related Functions
| Function or Approach | Difference |
|---|---|
mkdir() | Creates a directory, optionally creating intermediate directories recursively. |
is_dir() | Related approach. Its purpose and return value differ; select it when your task matches that operation. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Overlooking a special case of mkdir(). | Directory permissions are affected by umask; beware of race conditions when handling user-supplied paths. |
Using mkdir() without checking the outcome. | Handle failures and confirm that the output is suitable for the next step. |
Key Takeaways
- Creates a directory, optionally creating intermediate directories recursively.
- Directory permissions are affected by umask; beware of race conditions when handling user-supplied paths.
- Test the function with relevant inputs before using it in production.
Use mkdir when its behavior matches the job you need to complete. For dependable results, consider the input data, returned value and limitations shown above.