What potential pitfalls should be considered when using __FILE__ or __DIR__ in PHP?

When using __FILE__ or __DIR__ in PHP, it's important to be aware that these magic constants return the file path of the current file at the time of execution. This means that if the file is included or required from another file, the path returned may not be what is expected. To ensure consistency and accuracy, it's recommended to use the realpath() function to get the absolute path of the file.

// Get the absolute path of the current file using realpath()
$currentFilePath = realpath(__FILE__);

// Get the absolute path of the current directory using realpath()
$currentDirectoryPath = realpath(__DIR__);