diohsc-0.1.3: Opts.hs

-- This file is part of Diohsc
-- Copyright (C) 2020 Martin Bays <mbays@sdf.org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of version 3 of the GNU General Public License as
-- published by the Free Software Foundation, or any later version.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see http://www.gnu.org/licenses/.

{-# LANGUAGE Safe #-}

module Opts (usage, parseArgs, Opt(..)) where

import           System.Console.GetOpt

import           Version

data Opt
    = Restricted
    | Interactive
    | ScriptFile FilePath
    | OptCommand String
    | DataDir FilePath
    | Ghost
    | Ansi
    | NoAnsi
    | Help
    | Version
    deriving (Eq, Ord, Show)

options :: [OptDescr Opt]
options =
    [ Option ['d'] ["datadir"] (ReqArg DataDir "PATH") "data and config directory (default: ~/.diohsc)"
    , Option ['e'] ["command"] (ReqArg OptCommand "COMMAND") "execute command"
    , Option ['f'] ["file"] (ReqArg ScriptFile "PATH") "execute commands from file (\"-\" for stdin)"
    , Option ['i'] ["interact"] (NoArg Interactive) "interactive mode (assumed unless -e/-f used)"
    , Option ['c'] ["colour"] (NoArg Ansi) "use ANSI colour (assumed if stdout is term)"
    , Option ['C'] ["no-colour"] (NoArg NoAnsi) "do not use ANSI colour"
    , Option ['g'] ["ghost"] (NoArg Ghost) "write nothing to filesystem (unless commanded)"
    , Option ['r'] ["restricted"] (NoArg Restricted) "disallow shell and filesystem access"
    , Option ['v'] ["version"] (NoArg Version) "show version information"
    , Option ['h'] ["help"] (NoArg Help) "show usage information"
    ]

usage :: String
usage = usageInfo header options
    where header = "Usage: " ++ programName ++ " [OPTION...] [URI|PATH]"

parseArgs :: [String] -> IO ([Opt],[String])
parseArgs argv =
    case getOpt Permute options argv of
        (o,n,[])   -> return (o,n)
        (_,_,errs) -> ioError (userError (concat errs ++ usage))