the luash model can't work , please help me solve this problem

[TaoTaoFu]

th> local sh = require('sh')
                                                                      [0.0001s]
th> sh
function: 0x410888b0	
                                                                      [0.0001s]
th> local dockerbusybox = sh.command('docker', 'run', 'busybox')
[string "local dockerbusybox = sh.command('docker', 'r..."]:1: attempt to index global 'sh' (a function value)
stack traceback:
	[string "local dockerbusybox = sh.command('docker', 'r..."]:1: in main chunk
	[C]: in function 'xpcall'
	/home/tao/Datas/torch/install/share/lua/5.1/trepl/init.lua:679: in function 'repl'
	...atas/torch/install/lib/luarocks/rocks/trepl/scm-1/bin/th:204: in main chunk
	[C]: at 0x004065c0	
                                                                      [0.0002s]
th> dockerbusybox('echo', 'hello')
sh: 1: dockerbusybox: not found

                                                                      [0.0027s]

When I installed the sh as the command

   "luarocks install --server=http://luarocks.org/dev luash "

It's successful , but when I run the example as above ， the problem occured .

I don't know how to solve it, please help me sovle this problem. Thanks in advance ~ : )

[folknor]

It's because of how lua variables are looked up in the lua shell vs during full script interpretation; so these two things will produce different results.

test.lua:
#!/usr/bin/lua
local sh = require("sh")
print(type(sh))

$ lua test.lua
table

$ lua
Lua 5.2.4  Copyright (C) 1994-2015 Lua.org, PUC-Rio
> local sh = require("sh")
> print(type(sh))
function

And the reason this happens is because luash changes _G's metatable, adding a __index that translates all attempts at accessing unset _G.xyz members as invoking a shell command of the same name (xyz).

So in your shell, type(sh) == "function" is not a defined function from the library, it's a function that in turn would have invoked this shell command for you:
$ sh

Here is a snippet of the relevant code from https://github.com/zserge/luash/blob/master/sh.lua

local mt = getmetatable(_G)
if mt == nil then
  mt = {}
  setmetatable(_G, mt)
end

-- set hook for undefined variables
mt.__index = function(t, cmd)
	return command(cmd)
end