123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172 |
- <!-- $Id: lua.man,v 1.11 2006/01/06 16:03:34 lhf Exp $ -->
- <HTML>
- <HEAD>
- <TITLE>LUA man page</TITLE>
- <LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
- </HEAD>
- <BODY BGCOLOR="#FFFFFF">
- <H2>NAME</H2>
- lua - Lua interpreter
- <H2>SYNOPSIS</H2>
- <B>lua</B>
- [
- <I>options</I>
- ]
- [
- <I>script</I>
- [
- <I>args</I>
- ]
- ]
- <H2>DESCRIPTION</H2>
- <B>lua</B>
- is the stand-alone Lua interpreter.
- It loads and executes Lua programs,
- either in textual source form or
- in precompiled binary form.
- (Precompiled binaries are output by
- <B>luac</B>,
- the Lua compiler.)
- <B>lua</B>
- can be used as a batch interpreter and also interactively.
- <P>
- The given
- <I>options</I>
- (see below)
- are executed and then
- the Lua program in file
- <I>script</I>
- is loaded and executed.
- The given
- <I>args</I>
- are available to
- <I>script</I>
- as strings in a global table named
- <B>arg</B>.
- If these arguments contain spaces or other characters special to the shell,
- then they should be quoted
- (but note that the quotes will be removed by the shell).
- The arguments in
- <B>arg</B>
- start at 0,
- which contains the string
- '<I>script</I>'.
- The index of the last argument is stored in
- <B>arg.n</B>.
- The arguments given in the command line before
- <I>script</I>,
- including the name of the interpreter,
- are available in negative indices in
- <B>arg</B>.
- <P>
- At the very start,
- before even handling the command line,
- <B>lua</B>
- executes the contents of the environment variable
- <B>LUA_INIT</B>,
- if it is defined.
- If the value of
- <B>LUA_INIT</B>
- is of the form
- '@<I>filename</I>',
- then
- <I>filename</I>
- is executed.
- Otherwise, the string is assumed to be a Lua statement and is executed.
- <P>
- Options start with
- <B>'-'</B>
- and are described below.
- You can use
- <B>'--'</B>
- to signal the end of options.
- <P>
- If no arguments are given,
- then
- <B>"-v -i"</B>
- is assumed when the standard input is a terminal;
- otherwise,
- <B>"-"</B>
- is assumed.
- <P>
- In interactive mode,
- <B>lua</B>
- prompts the user,
- reads lines from the standard input,
- and executes them as they are read.
- If a line does not contain a complete statement,
- then a secondary prompt is displayed and
- lines are read until a complete statement is formed or
- a syntax error is found.
- So, one way to interrupt the reading of an incomplete statement is
- to force a syntax error:
- adding a
- <B>';'</B>
- in the middle of a statement is a sure way of forcing a syntax error
- (except inside multiline strings and comments; these must be closed explicitly).
- If a line starts with
- <B>'='</B>,
- then
- <B>lua</B>
- displays the values of all the expressions in the remainder of the
- line. The expressions must be separated by commas.
- The primary prompt is the value of the global variable
- <B>_PROMPT</B>,
- if this value is a string;
- otherwise, the default prompt is used.
- Similarly, the secondary prompt is the value of the global variable
- <B>_PROMPT2</B>.
- So,
- to change the prompts,
- set the corresponding variable to a string of your choice.
- You can do that after calling the interpreter
- or on the command line
- (but in this case you have to be careful with quotes
- if the prompt string contains a space; otherwise you may confuse the shell.)
- The default prompts are "> " and ">> ".
- <H2>OPTIONS</H2>
- <P>
- <B>-</B>
- load and execute the standard input as a file,
- that is,
- not interactively,
- even when the standard input is a terminal.
- <P>
- <B>-e </B><I>stat</I>
- execute statement
- <I>stat</I>.
- You need to quote
- <I>stat </I>
- if it contains spaces, quotes,
- or other characters special to the shell.
- <P>
- <B>-i</B>
- enter interactive mode after
- <I>script</I>
- is executed.
- <P>
- <B>-l </B><I>name</I>
- call
- <B>require</B>('<I>name</I>')
- before executing
- <I>script</I>.
- Typically used to load libraries.
- <P>
- <B>-v</B>
- show version information.
- <H2>SEE ALSO</H2>
- <B>luac</B>(1)
- <BR>
- <A HREF="http://www.lua.org/">http://www.lua.org/</A>
- <H2>DIAGNOSTICS</H2>
- Error messages should be self explanatory.
- <H2>AUTHORS</H2>
- R. Ierusalimschy,
- L. H. de Figueiredo,
- and
- W. Celes
- <!-- EOF -->
- </BODY>
- </HTML>
|