What potential issues can arise when using is_dir() and is_file() functions in PHP to differentiate between folders and files?

Potential issues can arise when using is_dir() and is_file() functions in PHP to differentiate between folders and files because symbolic links can cause unexpected results. To solve this issue, you can use the realpath() function to resolve the symbolic links before checking if the path is a directory or a file.

$path = '/path/to/file/or/folder';

// Resolve symbolic links
$realPath = realpath($path);

if ($realPath !== false) {
    if (is_dir($realPath)) {
        echo "The path is a directory.";
    } elseif (is_file($realPath)) {
        echo "The path is a file.";
    } else {
        echo "The path is neither a directory nor a file.";
    }
} else {
    echo "Invalid path.";
}