执行 Lua 程序
通常，Lua 附带两个二进制文件：
lua- 独立解释器和交互式 shellluac- 字节码编译器
让我们说我们有一个像这样的示例程序（bottles_of_mate.lua）：
local string = require "string"
function bottle_take(bottles_available)
local count_str = "%d bottles of mate on the wall."
local take_str = "Take one down, pass it around, " .. count_str
local end_str = "Oh noes, " .. count_str
local buy_str = "Get some from the store, " .. count_str
local bottles_left = 0
if bottles_available > 0 then
print(string.format(count_str, bottles_available))
bottles_left = bottles_available - 1
print(string.format(take_str, bottles_left))
else
print(string.format(end_str, bottles_available))
bottles_left = 99
print(string.format(buy_str, bottles_left))
end
return bottles_left
end
local bottle_count = 99
while true do
bottle_count = bottle_take(bottle_count)
end
可以通过在 shell 上执行以下命令来运行程序本身：
$ lua bottles_of_mate.lua
输出应该如下所示，在无限循环中运行：
Get some from the store, 99 bottles of mate on the wall.
99 bottles of mate on the wall.
Take one down, pass it around, 98 bottles of mate on the wall.
98 bottles of mate on the wall.
Take one down, pass it around, 97 bottles of mate on the wall.
97 bottles of mate on the wall.
...
...
3 bottles of mate on the wall.
Take one down, pass it around, 2 bottles of mate on the wall.
2 bottles of mate on the wall.
Take one down, pass it around, 1 bottles of mate on the wall.
1 bottles of mate on the wall.
Take one down, pass it around, 0 bottles of mate on the wall.
Oh noes, 0 bottles of mate on the wall.
Get some from the store, 99 bottles of mate on the wall.
99 bottles of mate on the wall.
Take one down, pass it around, 98 bottles of mate on the wall.
...
你可以通过在你的 shell 上执行以下命令将程序编译为 Lua 的字节码：
$ luac bottles_of_mate.lua -o bottles_of_mate.luac
字节码列表也可通过以下方式执行：
$ luac -l bottles_of_mate.lua
main <./bottles.lua:0,0> (13 instructions, 52 bytes at 0x101d530)
0+ params, 4 slots, 0 upvalues, 2 locals, 4 constants, 1 function
1 [1] GETGLOBAL 0 -1 ; require
2 [1] LOADK 1 -2 ; "string"
3 [1] CALL 0 2 2
4 [22] CLOSURE 1 0 ; 0x101d710
5 [22] MOVE 0 0
6 [3] SETGLOBAL 1 -3 ; bottle_take
7 [24] LOADK 1 -4 ; 99
8 [27] GETGLOBAL 2 -3 ; bottle_take
9 [27] MOVE 3 1
10 [27] CALL 2 2 2
11 [27] MOVE 1 2
12 [27] JMP -5 ; to 8
13 [28] RETURN 0 1
function <./bottles.lua:3,22> (46 instructions, 184 bytes at 0x101d710)
1 param, 10 slots, 1 upvalue, 6 locals, 9 constants, 0 functions
1 [5] LOADK 1 -1 ; "%d bottles of mate on the wall."
2 [6] LOADK 2 -2 ; "Take one down, pass it around, "
3 [6] MOVE 3 1
4 [6] CONCAT 2 2 3
5 [7] LOADK 3 -3 ; "Oh noes, "
6 [7] MOVE 4 1
7 [7] CONCAT 3 3 4
8 [8] LOADK 4 -4 ; "Get some from the store, "
9 [8] MOVE 5 1
10 [8] CONCAT 4 4 5
11 [9] LOADK 5 -5 ; 0
12 [11] EQ 1 0 -5 ; - 0
13 [11] JMP 16 ; to 30
14 [12] GETGLOBAL 6 -6 ; print
15 [12] GETUPVAL 7 0 ; string
16 [12] GETTABLE 7 7 -7 ; "format"
17 [12] MOVE 8 1
18 [12] MOVE 9 0
19 [12] CALL 7 3 0
20 [12] CALL 6 0 1
21 [13] SUB 5 0 -8 ; - 1
22 [14] GETGLOBAL 6 -6 ; print
23 [14] GETUPVAL 7 0 ; string
24 [14] GETTABLE 7 7 -7 ; "format"
25 [14] MOVE 8 2
26 [14] MOVE 9 5
27 [14] CALL 7 3 0
28 [14] CALL 6 0 1
29 [14] JMP 15 ; to 45
30 [16] GETGLOBAL 6 -6 ; print
31 [16] GETUPVAL 7 0 ; string
32 [16] GETTABLE 7 7 -7 ; "format"
33 [16] MOVE 8 3
34 [16] MOVE 9 0
35 [16] CALL 7 3 0
36 [16] CALL 6 0 1
37 [17] LOADK 5 -9 ; 99
38 [18] GETGLOBAL 6 -6 ; print
39 [18] GETUPVAL 7 0 ; string
40 [18] GETTABLE 7 7 -7 ; "format"
41 [18] MOVE 8 4
42 [18] MOVE 9 5
43 [18] CALL 7 3 0
44 [18] CALL 6 0 1
45 [21] RETURN 5 2
46 [22] RETURN 0 1