What are the methods of traversing directories in PHP?

In PHP, there are several ways to traverse directories.

1. opendir() and readdir(): open a directory using opendir(), then read the files and subdirectories within the directory using readdir().

$dir = opendir('/path/to/directory');

while (($file = readdir($dir)) !== false) {
    echo $file . "\n";
}

closedir($dir);

1. glob(): Retrieve a list of files in a specified directory using the glob() function.

$files = glob('/path/to/directory/*');

foreach ($files as $file) {
    echo $file . "\n";
}

1. RecursiveDirectoryIterator and RecursiveIteratorIterator: recursively traverse directories and their subdirectories to access files.

$dir = new RecursiveDirectoryIterator('/path/to/directory');
$files = new RecursiveIteratorIterator($dir);

foreach ($files as $file) {
    echo $file . "\n";
}

Each method has its own characteristics and uses, so you can choose the appropriate traversal method based on actual needs.