This paper explores the concept of file as directory (FAD) as a unified interface to structured data within a file by representing such a file as (virtual) directory and the structured data as subdirectories and subfiles. Transparent conversion of files an their structured data into directory trees is to be handled by virtual filesystem providers. This allows for arbitrary applications and programming languages to read and write data within supported file types without the need to understand the file format - e.g., in order to modify pixel values within an image file, paragraphs in a text document, or settings in a configuration file. Advantages of this approach compared to API-mediated file access might include better learnability, modularity, explorability, synchronous access, better integration of proprietary applications, and a few other nice features. While technical issues of the FAD concept have been discussed by developers in the past, no major operating system allows FAD at the moment. In this paper I present concept, advantages, limitations, and use cases of FAD.