simple-cmd-args
A thin layer over optparse-applicative that avoids type plumbing for
subcommands by using Parser (IO ())
.
Various wrapper functions are also provided for common option/arg idioms.
See the library’s documentation for details of all the functions provided.
Usage
$ cat readme.hs
import SimpleCmdArgs
import Control.Applicative (some)
import System.Directory
main =
simpleCmdArgs Nothing "readme example" "Longer description..." $
subcommands
[ Subcommand "echo" "Print words" $
putStrLn . unwords <$> some (strArg "STR...")
, Subcommand "ls" "List directory" $
ls <$> strArg "DIR"
, Subcommand "mkdir" "Create directory" $
mkdir <$> parentsOpt <*> strArg "DIR"
]
where
parentsOpt = switchWith 'p' "parents" "Make missing directories"
ls :: FilePath -> IO ()
ls dir =
listDirectory dir >>= mapM_ putStrLn
mkdir :: Bool -> FilePath -> IO ()
mkdir parents =
if parents then createDirectoryIfMissing True else createDirectory
$ ghc readme.hs
$ ./readme --help
readme example
Usage: readme COMMAND
Longer description...
Available options:
-h,--help Show this help text
Available commands:
echo Print words
ls List directory
mkdir Create directory
$ ./readme echo hello world
hello world
$ ./readme mkdir -h
Usage: readme mkdir [-p|--parents] DIR
Create directory
Available options:
-p,--parents Make missing directories
-h,--help Show this help text
Examples
See the examples.
Hackage packages using this library: https://packdeps.haskellers.com/reverse/simple-cmd-args