Nix's Simplified File System Object Model

# File System Object Nix uses a simplified model of the file system, which consists of file system objects. Every file system object is one of the following: - File - A possibly empty sequence of bytes for contents - A single boolean representing the [executable](https://en.m.wikipedia.org/wiki/File-system_permissions#Permissions) permission - Directory Mapping of names to child file system objects - [Symbolic link](https://en.m.wikipedia.org/wiki/Symbolic_link) An arbitrary string. Nix does not assign any semantics to symbolic links. File system objects and their children form a tree. A bare file or symlink can be a root file system object. Nix does not encode any other file system notions such as [hard links](https://en.m.wikipedia.org/wiki/Hard_link), [permissions](https://en.m.wikipedia.org/wiki/File-system_permissions), timestamps, or other metadata. ## Examples of file system objects A plain file: ``` 50 B, executable: false ``` An executable file: ``` 122 KB, executable: true ``` A symlink: ``` -> /usr/bin/sh ``` A directory with contents: ``` ├── bin │ └── hello: 35 KB, executable: true └── share ├── info │ └── hello.info: 36 KB, executable: false └── man └── man1 └── hello.1.gz: 790 B, executable: false ``` A directory that contains a symlink and other directories: ``` ├── bin -> share/go/bin ├── nix-support/ └── share/ ```

Nix utilizes a simplified file system model based on three types of objects: Files, Directories, and Symbolic Links. Files consist of a sequence of bytes and a single boolean indicating executability. Directories map names to child file system objects. Symbolic links are arbitrary strings that Nix does not assign any specific semantics to. This model deliberately omits other common file system notions such as hard links, detailed permissions, or timestamps. These objects form a tree structure, with examples provided for each type.