GREP PATTERN -A ∞

droowhile.hs

{-# LANGUAGE UnicodeSyntax #-}

import Control.Applicative ((<$>))
import System.Environment (getArgs)
import Text.Regex.Posix ((=~))

main ∷ IO ()
main = do
  pattern ← head <$> getArgs
  mapM_ putStrLn =<< dropWhile (\α → not $ α =~ pattern) . lines <$> getContents