json2dir: a JSON-to-directory converter, a fast alternative to home-manager for managing dotfiles

json2dir specifies a subset of JSON suitable for describing directory trees and provides a tool to instantiate such descriptions.

TL;DR:

example-tree.json:

{
  "file": "Hello, world!",
  "dir": {
    "subfile": "Content.\n",
    "subdir": {}
  },
  "symlink": ["link", "target path"],
  "script": ["script", "#!/bin/sh\necho Howdy!"]
}

cat example-tree.json | json2dir

Here, four files will be added to the current directory:

• file: a file with the text Hello, world!,
• dir: a directory with two entries in it,
• symlink: a symbolic link pointing to target path,
• script: an executable shell script that prints Howdy! when run.

Use cases

• Using json2dir with Nix as a home-manager alternative for managing dotfiles

Input schema

• Objects represent directories.
• Strings represent contents of files.
• Arrays are used to represent symlinks and executable files.
• Arrays of the form ["link", target] represent symlinks, second element representing the target of the symlink.
• Arrays of the form ["script", content] represent executable files, second representing the content of the script.

Caveats

Regular JSON constraints apply. In particular, the input must be UTF-8. Currently, there's no way to represent files containing non-UTF-8 content.

When using this utility to create files for other users, care must be taken in order to prevent TOCTOU (time of check, time of use) attacks (e.g. with symlinks).

Packaging

flake.nix contains a Nix package for json2dir.

Development

To build the project, run cargo build or nix build. If you're using rustup, rust-toolchain.toml is provided.

Useful scripts may be found in the scripts folder.

A Nix cache is available at https://json2dir.cachix.org.

Feel free to fork/open issues/submit PRs/etc.