gistfile1.txt

import Prelude hiding (catch)
import System (getArgs)
import System.IO (hPutStrLn, hSetBuffering, BufferMode(NoBuffering), hClose, Handle)
import System.IO.Error (isEOFError, IOError(..))
import Network (connectTo, PortID(..), withSocketsDo)
import Control.Concurrent (forkIO, threadDelay)
import Control.Exception 

delay :: Int
delay = 60

main :: IO ()
main = withSocketsDo $ do
    [host, port] <- getArgs
    forever host port


forever :: String -> String -> IO ()
forever host port = do
    pinger host port `catch` handler `finally` forever host port
        where
            handler :: SomeException -> IO ()         
            handler e = forever host port

pinger :: String -> String -> IO ()
pinger host port = do
    handle <- connectTo host $ PortNumber $ fromIntegral (read port :: Int)
    putStrLn "Sending ping to Nexus"
    hSetBuffering handle NoBuffering
    hPutStrLn handle "ping"
    hClose handle
    threadDelay $ (floor $ fromIntegral delay*1e6 :: Int)
    pinger host port