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	1	<!-- $Id: lua.man,v 1.11 2006/01/06 16:03:34 lhf Exp $ -->
	2	<HTML>
	3	<HEAD>
	4	<TITLE>LUA man page</TITLE>
	5	<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
	6	</HEAD>
	7
	8	<BODY BGCOLOR="#FFFFFF">
	9
	10	<H2>NAME</H2>
	11	lua - Lua interpreter
	12	<H2>SYNOPSIS</H2>
	13	<B>lua</B>
	14	[
	15	<I>options</I>
	16	]
	17	[
	18	<I>script</I>
	19	[
	20	<I>args</I>
	21	]
	22	]
	23	<H2>DESCRIPTION</H2>
	24	<B>lua</B>
	25	is the stand-alone Lua interpreter.
	26	It loads and executes Lua programs,
	27	either in textual source form or
	28	in precompiled binary form.
	29	(Precompiled binaries are output by
	30	<B>luac</B>,
	31	the Lua compiler.)
	32	<B>lua</B>
	33	can be used as a batch interpreter and also interactively.
	34	<P>
	35	The given
	36	<I>options</I>
	37	(see below)
	38	are executed and then
	39	the Lua program in file
	40	<I>script</I>
	41	is loaded and executed.
	42	The given
	43	<I>args</I>
	44	are available to
	45	<I>script</I>
	46	as strings in a global table named
	47	<B>arg</B>.
	48	If these arguments contain spaces or other characters special to the shell,
	49	then they should be quoted
	50	(but note that the quotes will be removed by the shell).
	51	The arguments in
	52	<B>arg</B>
	53	start at 0,
	54	which contains the string
	55	'<I>script</I>'.
	56	The index of the last argument is stored in
	57	<B>arg.n</B>.
	58	The arguments given in the command line before
	59	<I>script</I>,
	60	including the name of the interpreter,
	61	are available in negative indices in
	62	<B>arg</B>.
	63	<P>
	64	At the very start,
	65	before even handling the command line,
	66	<B>lua</B>
	67	executes the contents of the environment variable
	68	<B>LUA_INIT</B>,
	69	if it is defined.
	70	If the value of
	71	<B>LUA_INIT</B>
	72	is of the form
	73	'@<I>filename</I>',
	74	then
	75	<I>filename</I>
	76	is executed.
	77	Otherwise, the string is assumed to be a Lua statement and is executed.
	78	<P>
	79	Options start with
	80	<B>'-'</B>
	81	and are described below.
	82	You can use
	83	<B>'--'</B>
	84	to signal the end of options.
	85	<P>
	86	If no arguments are given,
	87	then
	88	<B>"-v -i"</B>
	89	is assumed when the standard input is a terminal;
	90	otherwise,
	91	<B>"-"</B>
	92	is assumed.
	93	<P>
	94	In interactive mode,
	95	<B>lua</B>
	96	prompts the user,
	97	reads lines from the standard input,
	98	and executes them as they are read.
	99	If a line does not contain a complete statement,
	100	then a secondary prompt is displayed and
	101	lines are read until a complete statement is formed or
	102	a syntax error is found.
	103	So, one way to interrupt the reading of an incomplete statement is
	104	to force a syntax error:
	105	adding a
	106	<B>';'</B>
	107	in the middle of a statement is a sure way of forcing a syntax error
	108	(except inside multiline strings and comments; these must be closed explicitly).
	109	If a line starts with
	110	<B>'='</B>,
	111	then
	112	<B>lua</B>
	113	displays the values of all the expressions in the remainder of the
	114	line. The expressions must be separated by commas.
	115	The primary prompt is the value of the global variable
	116	<B>_PROMPT</B>,
	117	if this value is a string;
	118	otherwise, the default prompt is used.
	119	Similarly, the secondary prompt is the value of the global variable
	120	<B>_PROMPT2</B>.
	121	So,
	122	to change the prompts,
	123	set the corresponding variable to a string of your choice.
	124	You can do that after calling the interpreter
	125	or on the command line
	126	(but in this case you have to be careful with quotes
	127	if the prompt string contains a space; otherwise you may confuse the shell.)
	128	The default prompts are "> " and ">> ".
	129	<H2>OPTIONS</H2>
	130	<P>
	131	<B>-</B>
	132	load and execute the standard input as a file,
	133	that is,
	134	not interactively,
	135	even when the standard input is a terminal.
	136	<P>
	137	<B>-e </B><I>stat</I>
	138	execute statement
	139	<I>stat</I>.
	140	You need to quote
	141	<I>stat </I>
	142	if it contains spaces, quotes,
	143	or other characters special to the shell.
	144	<P>
	145	<B>-i</B>
	146	enter interactive mode after
	147	<I>script</I>
	148	is executed.
	149	<P>
	150	<B>-l </B><I>name</I>
	151	call
	152	<B>require</B>('<I>name</I>')
	153	before executing
	154	<I>script</I>.
	155	Typically used to load libraries.
	156	<P>
	157	<B>-v</B>
	158	show version information.
	159	<H2>SEE ALSO</H2>
	160	<B>luac</B>(1)
	161	<BR>
	162	<A HREF="http://www.lua.org/">http://www.lua.org/</A>
	163	<H2>DIAGNOSTICS</H2>
	164	Error messages should be self explanatory.
	165	<H2>AUTHORS</H2>
	166	R. Ierusalimschy,
	167	L. H. de Figueiredo,
	168	and
	169	W. Celes
	170	<!-- EOF -->
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	172	</HTML>