luac -v (return code: 0)
Lua 5.2.4 Copyright (C) 1994-2015 Lua.org, PUC-Rio
luac --help (return code: 1)
luac: unrecognized option '--help'
usage: luac [options] [filenames]
Available options are:
-l list (use -l -l for full listing)
-o name output to file 'name' (default is "luac.out")
-p parse only
-s strip debug information
-v show version information
-- stop handling options
- stop handling options and process stdin