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<!-- $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>
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<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 orin 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 thenthe 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 andlines are read until a complete statement is formed ora syntax error is found.So, one way to interrupt the reading of an incomplete statement isto 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 theline. 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 interpreteror on the command line(but in this case you have to be careful with quotesif 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,andW. Celes<!-- EOF --></BODY></HTML>
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