Lua

Lua is a free, fast, embeddable, portable, small, powerful, yet simple, proven and robust scripting language or interpreter designed for extending applications. The Lua scripting language combines powerful data description constructs, which are based on extensible semantics and associative arrays, with simple procedural syntax.

The software is interpreted from bytecodes, dynamically typed, and features automatic memory management with garbage collection, making it the perfect tool for scripting, rapid prototyping, and configuration. Lua also includes a small library of C functions, written in ANSI C. Lua is pronounced “LOO-ah” and it means "Moon" in Portuguese.

Getting started with Lua

Lua installs a little bit different then other open source programs. After you have downloaded the latest release from Softoware or via the project’s official homepage (see link at the end of the article), extract the package with an archive manager utility on your Home directory, open your favorite Terminal app and move to the location of the extracted archive files (e.g. cd /home/softoware/lua-5.2.3 - replace ‘softoware’ with your username).

Then, run the ‘make linux’ command to compile Lua and create the executable, which will be located on the /src folder and usable right away. To install Lua system wide, run the ‘sudo make install’ command right after the compilation process. Use Lua from the shell prompt and view available command-line options, as well as the usage message by running the ‘lua --help’ command.

Command-line options

Like any other command-line program, Lua comes with a several options. These will allow you to execute a custom string, to ignore environment variables, to stop handling options, to enter the interactive mode after executing a script, to use a custom library, as well as to stop handling options and execute stdin. Run the ‘man lua’ command to learn how to use Lua.

What is new in this release:

• This is a bug-fix release.

What is new in version 5.3.1:

• This is a bug-fix release.

What is new in version 5.3.0:

• Main changes:
• integers (64-bit by default)
• official support for 32-bit numbers
• bitwise operators
• basic utf-8 support
• functions for packing and unpacking values
• Language:
• userdata can have any Lua value as uservalue
• integer division
• more flexible rules for some metamethods
• Libraries:
• ipairs and the table library respect metamethods
• strip option in string.dump
• table library respects metamethods
• new function table.move
• new function string.pack
• new function string.unpack
• new function string.packsize
• C API:
• simpler API for continuation functions in C
• lua_gettable and similar functions return type of resulted value
• strip option in lua_dump
• new function: lua_geti
• new function: lua_seti
• new function: lua_isyieldable
• new function: lua_numbertointeger
• new function: lua_rotate
• new function: lua_stringtonumber
• Lua standalone interpreter:
• can be used as calculator; no need to prefix with '='
• arg table available to all code

What is new in version 5.2.3:

• This is a bug-fix release.

What is new in version 5.2.1:

• This release fixes all known bugs.

What is new in version 5.2.0 RC2:

• Documentation and portability fixes.