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