NAME

hook.lua — bootloader hook module

DESCRIPTION

hook.lua contains functionality for defining hook types and attaching hooks. Hooks are functions used to attach custom behaviors at pre-defined points in loader execution. These pre-defined points are what we refer to as “hook types”. Hooks may also take an optional data parameter, which may or may not be populated by the caller.

Before using the functionality provided by hook.lua, it must be included with a statement such as the following:

local hook =
  require("hook")

Exported functions

The following functions are exported from hook.lua:

hook.registerType(hooktype): Adds hooktype as a recognized hook type. This allows functions to be added to run when hooks of this type are invoked using hook.runAll(hooktype).
hook.register(hooktype, hookfunc): Register hookfunc to be run when hooks of type hooktype are invoked.
hook.runAll(hooktype): Invoke all hooks registered for type hooktype. Hooks are invoked in the order in which they are registered.

Hook Naming Guidelines

Hook names should consist of the name of the module they are defined in, as well as a verb describing when the hook is executed, separated by a period. For example, “config.reloaded” is defined in the config.lua(8) module and run when the configuration is reloaded.

EXAMPLES

To register a hook to be run when configuration is reloaded:

local hook = require("hook")

local function configuration_was_reloaded()
	print("Configuration was reloaded!")
end

hook.register("config.reloaded", configuration_was_reloaded)

AUTHORS

The hook.lua file was originally written by Kyle Evans <kevans@FreeBSD.org>.