Installing the command-line executable

Assuming you have Rust/Cargo installed, run this command in a terminal:

cargo install ffs

It will make the ffs command available in your PATH if you've allowed the PATH to be modified when installing Rust. cargo uninstall ffs uninstalls.

Back to the crate overview.

Readme

ffs: the file filesystem

ffs, the file filesystem, let's you mount semi-structured data as a filesystem---a tree structure you already know how to work with!

Working with semi-structured data using command-line tools is hard. Tools like jq help a lot, but learning a new language for simple manipulations is a big ask. By mapping hard-to-parse trees into a filesystem, you can keep using the tools you know.

Example

Run ffs [file.blah] to mount file.blah at the mountpoint file. The final, updated version of the file will be outputted on stdout.

$ cat object.json 
{ "name": "Michael Greenberg", "eyes": 2, "fingernails": 10, "human": true }
$ ffs -o object_edited.json object.json &
[1] 60182
$ tree object
object
├── eyes
├── fingernails
├── human
└── name

0 directories, 4 files
$ echo Mikey Indiana >object/name
$ echo 1 >object/nose
$ mkdir object/pockets
$ cd object/pockets/
$ echo keys >pants
$ echo pen >shirt
$ cd ..
$ cd ..
$ umount object
$ 
[1]+  Done                    ffs -o object_edited.json object.json
$ cat object_edited.json 
{"eyes":2,"fingernails":10,"human":true,"name":"Mikey Indiana","nose":1,"pockets":{"pants":"keys","shirt":"pen"}}

You can specify an explicit mountpoint by running ffs -m MOUNT file; you can specify an output file with -o OUTPUT. You can edit a file in place by running ffs -i file---when the volume is unmounted, the resulting output will be written back to file.

External dependencies

You need an appropriate FUSE or macFUSE along with pkg-config.

See the GitHub build workflow for examples of external dependency installation.