module Main where

import qualified Data.ByteString.Char8 as B
import Bio.Seq
import Bio.Seq.IO
import System.Environment

main :: IO ()
main = do
    [fl, chr, start, end] <- getArgs
    withGenome fl $ \g -> do
        s <- getSeq g (B.pack chr, read start, read end) :: IO (Either String (DNA IUPAC))
        case s of
            Left err -> error err
            Right x -> B.putStrLn . toBS $ x