? PHP opendir(), readdir(), closedir()

? Overview

PHP provides several functions for interacting with directories, including opendir(), readdir(), and closedir(). These functions allow you to open a directory, read its contents, and then close the directory after you’re done working with it.

?️ Key Concepts

opendir() opens a directory and returns a handle.
readdir() reads directory entries one by one.
closedir() releases the directory resource.

? Syntax & Theory

opendir(path) requires read permission on the directory.
readdir(handle) returns file or directory names.
closedir(handle) should always be called after reading.

? Code Example

? View Code Example

// Open a directory, read files, and close it safely
<?php
$directory_path = "./myFolder";
$dir = opendir($directory_path);

if ($dir) {
echo "Files in '$directory_path':<br>";
while (($file = readdir($dir)) !== false) {
echo $file . "<br>";
}
closedir($dir);
} else {
echo "Failed to open directory.<br>";
}
?>

? Output / Explanation

The script opens the directory, loops through all entries, prints each file name, and finally closes the directory handle to free system resources.

? Interactive Understanding

Think of the directory handle as a pointer that moves forward each time readdir() is called, stopping when no more entries are available.

? Use Cases

Listing uploaded files.
Processing batch files.
Scanning folders for backups or logs.

✅ Tips & Best Practices

Always validate directory paths before opening.
Skip . and .. entries during iteration.
Close directories to prevent memory leaks.

? Try It Yourself

Count files in a directory using readdir().
Filter files by extension.
Test behavior with nested directories.