Lua scripting language

Introduction

This plugin is an interpreter for the Lua language. To quote from the Lua website ( http://www.lua.org), Lua is a “powerful, fast, lightweight, embeddable scripting language”. Select a .lua file in the File Browser to run it. For more information on programming in Lua, please see http://www.lua.org/manual/5.1/ and http://www.lua.org/pil/.

There are a few exceptions/additions to the Lua support in Rockbox:

• No floating point support.
  • The number type in Lua is usually float, however in the Rockbox implementation it is integer.
• Non-supported libraries.
  • The coroutine, debug and math libraries are not supported.
• Partially-supported libraries.
  • The os and package libraries are only partially supported.
• Additional libraries.
  • The bitlib library is integrated to support bitwise operators. See http://luaforge.net/projects/bitlib and http://lua-users.org/wiki/BitwiseOperators.

Documentation of the API is still a work in progress, and the API itself is not finalised. For the latest information, see PluginLua?.

Note: Please note that if a script does not provide a way to exit, then the only way to exit will be to reset the player.

API

The plugin API and some Rockbox C functions are directly exposed in the rb table. Have a look at the source code for more info (like plugin.h and others).

To generate a /rb.txt file containing the keys of the rb object, you can run this code:

rb_obj = {}
for k, v in pairs(rb) do
    local the_type = type(v)..'s'
    if not rb_obj[the_type] then
        rb_obj[the_type] = {}
        end
    table.insert(rb_obj[the_type], k)
    end

local list = {}
for rb_type, rb_table in pairs(rb_obj) do
    table.insert(list, string.format('* %s *', rb_type))
    table.sort(rb_table)
    for _, v in ipairs(rb_table) do
        table.insert(list, v)
        end
    -- jump a line
    table.insert(list, '')
    end
local file = io.open('/rb.txt', "w+")
file:write(table.concat(list, '\n'))
file:close()

Example

Note that the following example may not be up to date with the current version of the Lua plugin.

function sayhello(seconds)
  local message = string.format("Hello from LUA for %d seconds", 5)
  rb.splash(seconds, message)
end

-- Drawn an X on the screen
rb.lcd_clear_display()
rb.lcd_drawline(0, 0, rb.LCD_WIDTH, rb.LCD_HEIGHT)
rb.lcd_drawline(rb.LCD_WIDTH, 0, 0, rb.LCD_HEIGHT)
rb.lcd_update()

local seconds = 5

rb.sleep(5 * rb.HZ)

sayhello(seconds)

There's also a helloworld example script in SVN, see apps/plugins/helloworld.lua

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CategoryPlugin: Lua interpreter [Sansa Clip, Sansa Fuze, Sansa e200, Sansa c200, iPod 1G2G, iPod 3G, iPod 4G, iPod Color, iPod Video, iPod Mini, iPod Nano, Gigabeat, MR-100, iAudio M5, iAudio X5, H100, H300, H10]