freebsd-dev/stand/lua/cli.lua.8

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.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
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.Dd October 31, 2018
.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
As of present, the
.Nm
module by default provides commands for
.Ic autoboot ,
.Ic boot ,
and
.Ic boot-conf.
In all three cases, 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.
.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 .