Filesystem Librarian

Librarian runs pre-configured commands against a group of files that match a set of filters. The group of files is called a library. Librarian can either search for files in a library or watch for when files in the library are created or updated.

To run Librarian once, where it exits after searching through a list of configured libraries, run:

sh fs-librarian single-shot path/to/config.toml

To make Librarian continually watch for when files in configured libraries are created or updated, run:

sh fs-librarian watch path/to/config.toml

Building

You can use the pre-built binaries on the release page or build Librarian on your own. To build Librarian, make sure you have Rust installed on your machine (installation instructions are here) then run:

sh make clean build

The binary target/release/fs-librarian will be generated.

Configuration

An example configuration file can be found here.

Libraries

In the Librarian configuration file, define one or more "libraries" of files. A library is a set of files that match defined search filters. Supported search filters are:

• A required list of parent directories the file can be in
• An optional list of regexes the file's MIME type should match

For each of the defined libraries, provide a Tera template (whose syntax is based on Jinja2) of the command that should run when a file is found. The following variables are available to the template:

• {{ file_path }}: The path to the file that was found
• {{ mime_type }}: The MIME type for the file that was found. Run the fs-librarian test mime <path to a file> command to display the MIME types of files you are unsure about.

The following configuration snippet defines a music library which watches for files inside the Downloads and /tmp directories that have MIME types matching the audio/.+ regex (e.g. audio/flac and audio/ogg). When an audio file is found, it is moved to the Music directory:

```toml [libraries.music] command = """ mv "{{ file_path }}" /home/jrogena/Music/ """

[libraries.music.filter] directories = [ "/home/jrogena/Downloads", "/tmp" ] mimetyperegexes = [ "audio/.+" ] ```

Filesystem Watching

The following configurations, related to filesystem watching, are available:

• min_command_exec_freq: Optional. The minimum frequency (in seconds) between running the configured command against a file. Useful in situations where a file is updated frequently but you don't want Librarian to run against the file as frequently as it is updated.

  The following snippet is an example filesystem watching configuration:

toml [fs_watch] min_command_exec_freq = 60

Considerations

Consider the following when using Librarian:

• Librarian does not limit itself to files in the root of the configured filter directories. It will also consider files in sub-directories.
• The pre-configured commands will run concurrently against your libraries. In single-shot mode, a separate thread will be used for each of the configured libraries. Watch mode will use a separate thread for each file-update notification. Race conditions might occur if the same file matches the filters for more than one library or if a pre-configured command you provide isn't safe to be run more than once, concurrently, against the same file.
• Librarian relies on OS-specific MIME-type databases. Therefore, it is possible for the same file to appear to have a different MIME-type on different OSs.
• In watch mode, expect that the pre-configured command will be called more than once when a file is created or updated (once for each file-update notification emitted by the OS). Some OSs emit more than one notification (e.g. IN_CREATE and IN_CLOSE_WRITE on Linux) when a file is changed. You can avoid the pre-configured command from running more than once for every file update using the min_command_exec_freq option.
• Use absolute paths in your configuration files. Librarian might not behave as expected if you use relative paths.

License

MIT