Question

I have a file main.lua:

require("hello")

and a file hello.lua in the directory foo bar! baz (with !) in it:

module(...,package.seeall)
print("hello from hello.lua")

when I set (on Windows) the environment variable LUA_PATH to the directory:

set LUA_PATH="C:\Programme\Lua\5.1\foo bar! baz\?.lua"

I get a strange error:

C:\Programme\Lua\5.1>lua main.lua
lua: main.lua:4: module 'hello' not found:
        no field package.preload['hello']
        no file '"C:\Programme\Lua\5.1\foo barC:\Programme\Lua\5.1 baz\hello.lua
"'
        no file '.\hello.dll'
        no file '.\hello51.dll'
        no file 'C:\Programme\Lua\5.1\hello.dll'
        no file 'C:\Programme\Lua\5.1\hello51.dll'
        no file 'C:\Programme\Lua\5.1\clibs\hello.dll'
        no file 'C:\Programme\Lua\5.1\clibs\hello51.dll'
        no file 'C:\Programme\Lua\5.1\loadall.dll'
        no file 'C:\Programme\Lua\5.1\clibs\loadall.dll'
stack traceback:
        [C]: in function 'require'
        main.lua:4: in main chunk
        [C]: ?

See the very strange path C:\Programme\Lua\5.1\foo barC:\Programme\Lua\5.1 baz\hello.lua? What is so special about the exclamation mark (bang)? How to get that right in windows? On Mac this seems to be working fine.

Answer 1

“This substitution only happens the first time Lua sets the path
(either from LUA_PATH or from the default from luaconf). If you
set the path by other means, you can avoid the problem.”

More info and potential alternatives: http://lua-users.org/lists/lua-l/2012-08/msg00052.html