1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<TITLE>Lua 5.2 readme</TITLE> 5<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css"> 6<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1"> 7<STYLE TYPE="text/css"> 8blockquote, .display { 9 border: solid #a0a0a0 2px ; 10 padding: 1em ; 11 margin: 0px ; 12} 13 14.display { 15 word-spacing: 0.25em ; 16} 17 18dl.display dd { 19 padding-bottom: 0.2em ; 20} 21 22tt, kbd, code { 23 font-size: 12pt ; 24} 25</STYLE> 26</HEAD> 27 28<BODY> 29 30<HR> 31<H1> 32<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua" BORDER=0></A> 33Welcome to Lua 5.2 34</H1> 35 36<P> 37<A HREF="#about">about</A> 38· 39<A HREF="#install">installation</A> 40· 41<A HREF="#changes">changes</A> 42· 43<A HREF="#license">license</A> 44· 45<A HREF="contents.html">reference manual</A> 46 47<H2><A NAME="about">About Lua</A></H2> 48 49<P> 50Lua is a powerful, fast, lightweight, embeddable scripting language 51developed by a 52<A HREF="http://www.lua.org/authors.html">team</A> 53at 54<A HREF="http://www.puc-rio.br/">PUC-Rio</A>, 55the Pontifical Catholic University of Rio de Janeiro in Brazil. 56Lua is 57<A HREF="#license">free software</A> 58used in many products and projects around the world. 59 60<P> 61Lua's 62<A HREF="http://www.lua.org/">official web site</A> 63provides complete information 64about Lua, 65including 66an 67<A HREF="http://www.lua.org/about.html">executive summary</A> 68and 69updated 70<A HREF="http://www.lua.org/docs.html">documentation</A>, 71especially the 72<A HREF="http://www.lua.org/manual/5.2/">reference manual</A>, 73which may differ slightly from the 74<A HREF="contents.html">local copy</A> 75distributed in this package. 76 77<H2><A NAME="install">Installing Lua</A></H2> 78 79<P> 80Lua is distributed in 81<A HREF="http://www.lua.org/ftp/">source</A> 82form. 83You need to build it before using it. 84Building Lua should be straightforward 85because 86Lua is implemented in pure ANSI C and compiles unmodified in all known 87platforms that have an ANSI C compiler. 88Lua also compiles unmodified as C++. 89The instructions given below for building Lua are for Unix-like platforms. 90See also 91<A HREF="#other">instructions for other systems</A> 92and 93<A HREF="#customization">customization options</A>. 94 95<P> 96If you don't have the time or the inclination to compile Lua yourself, 97get a binary from 98<A HREF="http://lua-users.org/wiki/LuaBinaries">LuaBinaries</A>. 99Try also 100<A HREF="http://luaforwindows.luaforge.net/">Lua for Windows</A>, 101an easy-to-use distribution of Lua that includes many useful libraries. 102 103<H3>Building Lua</H3> 104 105<P> 106In most Unix-like platforms, simply do "<KBD>make</KBD>" with a suitable target. 107Here are the details. 108 109<OL> 110<LI> 111Open a terminal window and move to 112the top-level directory, which is named <TT>lua-5.2.2</TT>. 113The Makefile there controls both the build process and the installation process. 114<P> 115<LI> 116 Do "<KBD>make</KBD>" and see if your platform is listed. 117 The platforms currently supported are: 118<P> 119<P CLASS="display"> 120 aix ansi bsd freebsd generic linux macosx mingw posix solaris 121</P> 122<P> 123 If your platform is listed, just do "<KBD>make xxx</KBD>", where xxx 124 is your platform name. 125<P> 126 If your platform is not listed, try the closest one or posix, generic, 127 ansi, in this order. 128<P> 129<LI> 130The compilation takes only a few moments 131and produces three files in the <TT>src</TT> directory: 132lua (the interpreter), 133luac (the compiler), 134and liblua.a (the library). 135<P> 136<LI> 137 To check that Lua has been built correctly, do "<KBD>make test</KBD>" 138 after building Lua. This will run the interpreter and print its version string. 139</OL> 140<P> 141If you're running Linux and get compilation errors, 142make sure you have installed the <TT>readline</TT> development package. 143If you get link errors after that, 144then try "<KBD>make linux MYLIBS=-ltermcap</KBD>". 145 146<H3>Installing Lua</H3> 147<P> 148 Once you have built Lua, you may want to install it in an official 149 place in your system. In this case, do "<KBD>make install</KBD>". The official 150 place and the way to install files are defined in the Makefile. You'll 151 probably need the right permissions to install files. 152 153<P> 154 To build and install Lua in one step, do "<KBD>make xxx install</KBD>", 155 where xxx is your platform name. 156 157<P> 158 To install Lua locally, do "<KBD>make local</KBD>". 159 This will create a directory <TT>install</TT> with subdirectories 160 <TT>bin</TT>, <TT>include</TT>, <TT>lib</TT>, <TT>man</TT>, 161 and install Lua as listed below. 162 163 To install Lua locally, but in some other directory, do 164 "<KBD>make install INSTALL_TOP=xxx</KBD>", where xxx is your chosen directory. 165 166<DL CLASS="display"> 167<DT> 168 bin: 169<DD> 170 lua luac 171<DT> 172 include: 173<DD> 174 lua.h luaconf.h lualib.h lauxlib.h lua.hpp 175<DT> 176 lib: 177<DD> 178 liblua.a 179<DT> 180 man/man1: 181<DD> 182 lua.1 luac.1 183</DL> 184 185<P> 186 These are the only directories you need for development. 187 If you only want to run Lua programs, 188 you only need the files in bin and man. 189 The files in include and lib are needed for 190 embedding Lua in C or C++ programs. 191 192<H3><A NAME="customization">Customization</A></H3> 193<P> 194 Three kinds of things can be customized by editing a file: 195<UL> 196 <LI> Where and how to install Lua — edit <TT>Makefile</TT>. 197 <LI> How to build Lua — edit <TT>src/Makefile</TT>. 198 <LI> Lua features — edit <TT>src/luaconf.h</TT>. 199</UL> 200 201<P> 202 You don't actually need to edit the Makefiles because you may set the 203 relevant variables in the command line when invoking make. 204 Nevertheless, it's probably best to edit and save the Makefiles to 205 record the changes you need. 206 207<P> 208 On the other hand, if you need to customize some Lua features, you'll need 209 to edit <TT>src/luaconf.h</TT> before building and installing Lua. 210 The edited file will be the one installed, and 211 it will be used by any Lua clients that you build, to ensure consistency. 212 Further customization is available to experts by editing the Lua sources. 213 214<P> 215 We strongly recommend that you enable dynamic loading in <TT>src/luaconf.h</TT>. 216 This is done automatically for all platforms listed above that have 217 this feature and also for Windows. 218 219<H3><A NAME="other">Building Lua on other systems</A></H3> 220 221<P> 222 If you're not using the usual Unix tools, then the instructions for 223 building Lua depend on the compiler you use. You'll need to create 224 projects (or whatever your compiler uses) for building the library, 225 the interpreter, and the compiler, as follows: 226 227<DL CLASS="display"> 228<DT> 229library: 230<DD> 231lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c 232lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c 233ltm.c lundump.c lvm.c lzio.c 234lauxlib.c lbaselib.c lbitlib.c lcorolib.c ldblib.c liolib.c 235lmathlib.c loslib.c lstrlib.c ltablib.c loadlib.c linit.c 236<DT> 237interpreter: 238<DD> 239 library, lua.c 240<DT> 241compiler: 242<DD> 243 library, luac.c 244</DL> 245 246<P> 247 To use Lua as a library in your own programs you'll need to know how to 248 create and use libraries with your compiler. Moreover, to dynamically load 249 C libraries for Lua you'll need to know how to create dynamic libraries 250 and you'll need to make sure that the Lua API functions are accessible to 251 those dynamic libraries — but <EM>don't</EM> link the Lua library 252 into each dynamic library. For Unix, we recommend that the Lua library 253 be linked statically into the host program and its symbols exported for 254 dynamic linking; <TT>src/Makefile</TT> does this for the Lua interpreter. 255 For Windows, we recommend that the Lua library be a DLL. 256 257<P> 258 As mentioned above, you may edit <TT>src/luaconf.h</TT> to customize 259 some features before building Lua. 260 261<H2><A NAME="changes">Changes since Lua 5.1</A></H2> 262 263<P> 264Here are the main changes introduced in Lua 5.2. 265The 266<A HREF="contents.html">reference manual</A> 267lists the 268<A HREF="manual.html#8">incompatibilities</A> that had to be introduced. 269 270<H3>Main changes</H3> 271<UL> 272<LI> yieldable pcall and metamethods 273<LI> new lexical scheme for globals 274<LI> ephemeron tables 275<LI> new library for bitwise operations 276<LI> light C functions 277<LI> emergency garbage collector 278<LI> <CODE>goto</CODE> statement 279<LI> finalizers for tables 280</UL> 281 282Here are the other changes introduced in Lua 5.2: 283<H3>Language</H3> 284<UL> 285<LI> no more fenv for threads or functions 286<LI> tables honor the <CODE>__len</CODE> metamethod 287<LI> hex and <CODE>\z</CODE> escapes in strings 288<LI> support for hexadecimal floats 289<LI> order metamethods work for different types 290<LI> no more verification of opcode consistency 291<LI> hook event "tail return" replaced by "tail call" 292<LI> empty statement 293<LI> <CODE>break</CODE> statement may appear in the middle of a block 294</UL> 295 296<H3>Libraries</H3> 297<UL> 298<LI> arguments for function called through <CODE>xpcall</CODE> 299<LI> optional 'mode' argument to load and loadfile (to control binary x text) 300<LI> optional 'env' argument to load and loadfile (environment for loaded chunk) 301<LI> <CODE>loadlib</CODE> may load libraries with global names (RTLD_GLOBAL) 302<LI> new function <CODE>package.searchpath</CODE> 303<LI> modules receive their paths when loaded 304<LI> optional base in <CODE>math.log</CODE> 305<LI> optional separator in <CODE>string.rep</CODE> 306<LI> <CODE>file:write</CODE> returns <CODE>file</CODE> 307<LI> closing a pipe returns exit status 308<LI> <CODE>os.exit</CODE> may close state 309<LI> new metamethods <CODE>__pairs</CODE> and <CODE>__ipairs</CODE> 310<LI> new option 'isrunning' for <CODE>collectgarbage</CODE> and <CODE>lua_gc</CODE> 311<LI> frontier patterns 312<LI> <CODE>\0</CODE> in patterns 313<LI> new option <CODE>*L</CODE> for <CODE>io.read</CODE> 314<LI> options for <CODE>io.lines</CODE> 315<LI> <CODE>debug.getlocal</CODE> can access function varargs 316</UL> 317 318<H3>C API</H3> 319<UL> 320<LI> main thread predefined in the registry 321<LI> new functions 322<CODE>lua_absindex</CODE>, 323<CODE>lua_arith</CODE>, 324<CODE>lua_compare</CODE>, 325<CODE>lua_copy</CODE>, 326<CODE>lua_len</CODE>, 327<CODE>lua_rawgetp</CODE>, 328<CODE>lua_rawsetp</CODE>, 329<CODE>lua_upvalueid</CODE>, 330<CODE>lua_upvaluejoin</CODE>, 331<CODE>lua_version</CODE>. 332<LI> new functions 333<CODE>luaL_checkversion</CODE>, 334<CODE>luaL_setmetatable</CODE>, 335<CODE>luaL_testudata</CODE>, 336<CODE>luaL_tolstring</CODE>. 337<LI> <CODE>lua_pushstring</CODE> and <CODE>pushlstring</CODE> return string 338<LI> <CODE>nparams</CODE> and <CODE>isvararg</CODE> available in debug API 339<LI> new <CODE>lua_Unsigned</CODE> 340</UL> 341 342<H3>Implementation</H3> 343<UL> 344<LI> max constants per function raised to 2<SUP>26</SUP> 345<LI> generational mode for garbage collection (experimental) 346<LI> NaN trick (experimental) 347<LI> internal (immutable) version of ctypes 348<LI> simpler implementation for string buffers 349<LI> parser uses much less C-stack space (no more auto arrays) 350</UL> 351 352<H3>Lua standalone interpreter</H3> 353<UL> 354<LI> new <CODE>-E</CODE> option to avoid environment variables 355<LI> handling of non-string error messages 356</UL> 357 358<H2><A NAME="license">License</A></H2> 359<A HREF="http://www.opensource.org/docs/definition.php"> 360<IMG SRC="osi-certified-72x60.png" ALIGN="right" BORDER="0" ALT="[osi certified]" STYLE="padding-left: 30px ;"> 361</A> 362 363<P> 364Lua is free software distributed under the terms of the 365<A HREF="http://www.opensource.org/licenses/mit-license.html">MIT license</A> 366reproduced below; 367it may be used for any purpose, including commercial purposes, 368at absolutely no cost without having to ask us. 369 370The only requirement is that if you do use Lua, 371then you should give us credit by including the appropriate copyright notice somewhere in your product or its documentation. 372 373For details, see 374<A HREF="http://www.lua.org/license.html">this</A>. 375 376<BLOCKQUOTE STYLE="padding-bottom: 0em"> 377Copyright © 1994–2013 Lua.org, PUC-Rio. 378 379<P> 380Permission is hereby granted, free of charge, to any person obtaining a copy 381of this software and associated documentation files (the "Software"), to deal 382in the Software without restriction, including without limitation the rights 383to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 384copies of the Software, and to permit persons to whom the Software is 385furnished to do so, subject to the following conditions: 386 387<P> 388The above copyright notice and this permission notice shall be included in 389all copies or substantial portions of the Software. 390 391<P> 392THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 393IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 394FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 395AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 396LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 397OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 398THE SOFTWARE. 399</BLOCKQUOTE> 400<P> 401 402<HR> 403<SMALL CLASS="footer"> 404Last update: 405Fri Feb 22 09:24:20 BRT 2013 406</SMALL> 407<!-- 408Last change: revised for Lua 5.2.2 409--> 410 411</BODY> 412</HTML> 413