HardenedBSD/stand/lua/cli.lua.8

.\"
.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd July 24, 2021
.Dt CLI.LUA 8
.Os
.Sh NAME
.Nm cli.lua
.Nd FreeBSD Lua CLI module
.Sh DESCRIPTION
.Nm
contains the main functionality required to add new CLI commands, which can be
executed at the loader prompt.
.Pp
Before hooking into the functionality provided by
.Nm ,
it must be included with a statement such as the following:
.Pp
.Dl local cli = require("cli")
.Ss Adding new commands
New loader commands may be created by adding functions to the object returned by
requiring the
.Nm
module.
.Pp
For instance:
.Pp
.Bd -literal -offset indent -compact
local cli = require("cli")

cli.foo = function(...)
	-- Expand args to command name and the rest of argv.  These arguments
	-- are pushed directly to the stack by loader, then handed off to
	-- cli_execute.  cli_execute then passes them on to the invoked
	-- function, where they appear as varargs that must be peeled apart into
	-- their respective components.
	local _, argv = cli.arguments(...)

	print("This is the foo command!")
	for k, v in ipairs(argv) do
		print("arg #" .. tostring(k) .. ": '" .. v .. "'")
	end
	-- Perform a loader command directly.  This will not get dispatched back
	-- to Lua, so it is acceptable to have a function of the exact same name
	-- in loader.  Lua will have the first chance to handle any commands
	-- executed at the loader prompt.
	loader.perform("foo")
end
.Ed
.Pp
This function may be invoked by a user at the loader prompt by simply typing
.Ic foo .
Arguments may be passed to it as usual, space-delimited.
.Ss Default Commands
The
.Nm
module provides the following default commands:
.Bl -bullet
.\"-width toggle-module -offset indent
.It
.Ic autoboot
.It
.Ic boot
.It
.Ic boot-conf
.It
.Ic reload-conf
.It
.Ic disable-device
.It
.Ic disable-module
.It
.Ic enable-module
.It
.Ic toggle-module
.It
.Ic show-module-options
.El
.Pp
For
.Ic autoboot ,
.Ic boot ,
and
.Ic boot-conf ,
the
.Xr core.lua 8
module will load all ELF modules as-needed before executing the equivalent
built-in loader commands.
All non-kernel arguments to these commands are passed in the same order to the
loader command.
.Pp
The
.Ic reload-conf
command will reload the configuration from disk.
This is useful if you have manually changed currdev and would like to easily
reload the configuration from the new device.
.Pp
The
.Ic enable-module ,
.Ic disable-module ,
and
.Ic toggle-module
commands manipulate the list of modules to be loaded along with the kernel.
Modules blacklisted are considered disabled by
.Ic toggle-module .
These commands will override any such restriction as needed.
The
.Ic show-module-options
command will dump the list of modules that loader has been made aware of and
any applicable options using paged output.
.Pp
The
.Ic disable-device
command sets the environment variable that disables the device argument.
.Ss Exported Functions
The following functions are exported from
.Nm :
.Bl -tag -width cli.arguments -offset indent
.It Fn cli.arguments ...
Takes varargs passed on the stack from
.Xr loader 8
to
.Ic cli_execute ,
splits them out into two return values: the command name, traditionally argv[0],
and the rest of argv.
.El
.Sh SEE ALSO
.Xr loader.conf 5 ,
.Xr core.lua 8 ,
.Xr loader 8
.Sh AUTHORS
The
.Nm
file was originally written by
.An Kyle Evans Aq Mt kevans@FreeBSD.org .