使用 Lua 显示消息

fltk4lua 对于像这样简单的东西来说很容易，是的。

#! /usr/bin/env lua
--  sudo apt install libfltk1.3-dev
--  luarocks install fltk4lua

local fl = require( 'fltk4lua' )
fl .scheme( 'gtk+' )

local Width, Height = 300, 200
local Title = 'Lua 输出'
local window = fl .Window( Width, Height, Title )

local icon = fl .Chart{ Width *0.1,  Height *0.1,  100,  100,  type = FL_BAR_CHART }
local text = fl .Box{ Width *0.5,  Height *0.3,  100,  30,  'Hello World!' }
local button = fl .Button{ Width *0.5,  Height *0.75,  100,  30,  'Okay' }

icon :add( 6,  6,  0x05 )  --   www.fltk.org/doc-1.3/drawing.html#drawing_colors
icon :add( 5,  5,  0x04 )
icon :add( 4,  4,  0x02 )
icon :add( 3,  3,  0x01 )

window :end_group()
window :show( arg )
fl .run()