luac50 -v (return code: 0)
Lua 5.0.3 Copyright (C) 1994-2006 Tecgraf, PUC-Rio
luac50 --help (return code: 1)
luac50: unrecognized option `--help'
usage: luac50 [options] [filenames]. Available options are:
- process stdin
-l list
-o name output to file `name' (default is "luac.out")
-p parse only
-s strip debug information
-v show version information
-- stop handling options