git-annex/CmdLine.hs
2010-12-30 15:15:22 -04:00

66 lines
2 KiB
Haskell

{- git-annex command line parsing
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module CmdLine (
parseCmd,
Option,
storeOptBool,
storeOptString,
) where
import System.Console.GetOpt
import Control.Monad (when)
import Control.Monad.State (liftIO)
import qualified Annex
import Types
import Command
{- Each dashed command-line option results in generation of an action
- in the Annex monad that performs the necessary setting.
-}
type Option = OptDescr (Annex ())
storeOptBool :: FlagName -> Bool -> Annex ()
storeOptBool name val = Annex.flagChange name $ FlagBool val
storeOptString :: FlagName -> String -> Annex ()
storeOptString name val = Annex.flagChange name $ FlagString val
{- Parses command line, stores configure flags, and returns a
- list of actions to be run in the Annex monad. -}
parseCmd :: [String] -> String -> [Command] -> [Option] -> Annex [Annex Bool]
parseCmd argv header cmds options = do
(flags, params) <- liftIO $ getopt
when (null params) $ error usagemsg
case lookupCmd (head params) of
[] -> error usagemsg
[command] -> do
_ <- sequence flags
prepCmd command (drop 1 params)
_ -> error "internal error: multiple matching commands"
where
getopt = case getOpt Permute options argv of
(flags, params, []) -> return (flags, params)
(_, _, errs) -> ioError (userError (concat errs ++ usagemsg))
lookupCmd cmd = filter (\c -> cmd == cmdname c) cmds
usagemsg = usage header cmds options
{- Usage message with lists of commands and options. -}
usage :: String -> [Command] -> [Option] -> String
usage header cmds options =
usageInfo header options ++ "\nSubcommands:\n" ++ cmddescs
where
cmddescs = unlines $ map (indent . showcmd) cmds
showcmd c =
cmdname c ++
pad (longest cmdname + 1) (cmdname c) ++
cmdparams c ++
pad (longest cmdparams + 2) (cmdparams c) ++
cmddesc c
indent l = " " ++ l
pad n s = replicate (n - length s) ' '
longest f = foldl max 0 $ map (length . f) cmds