# 7.3.44. `plugin_register`

New in version 5.0.1.

## 7.3.44.1. Summary

`plugin_register` command registers a plugin. You need to register a plugin before you use a plugin.

You need just one `plugin_register` command for a plugin in the same database because registered plugin information is written into the database. When you restart your `groonga` process, `groonga` process loads all registered plugins without `plugin_register` command.

You can unregister a registered plugin by plugin_unregister.

## 7.3.44.2. Syntax

This command takes only one required parameter:

    plugin_register name

## 7.3.44.3. Usage

Here is a sample that registers `QueryExpanderTSV` query expander that is included in `${PREFIX}/lib/groonga/plugins/query_expanders/tsv.so`.

Execution example:

    plugin_register query_expanders/tsv
    # [[0, 1337566253.89858, 0.000355720520019531], true]

You can omit `${PREFIX}/lib/groonga/plugins/` and suffix (`.so`). They are completed automatically.

You can specify absolute path such as `plugin_register /usr/lib/groonga/plugins/query_expanders/tsv.so`.

## 7.3.44.4. Return value

`plugin_register` returns `true` as body on success such as:

    [HEADER, true]

If `plugin_register` fails, error details are in `HEADER`.

See Output format for `HEADER`.

## 7.3.44.5. See also

- plugin_unregister