select-0.4: example/FdSetExample.hs

module Main where

import Prelude hiding (elem)
import System.Posix.IO
import System.Posix.IO.Select.FdSet.Unsafe
import System.Posix.IO.Select.Types

flags :: OpenFileFlags
flags = OpenFileFlags { append = False, exclusive = False, noctty = False, nonBlock = True, trunc = False }

main :: IO ()
main = openFd "fifo" ReadOnly Nothing flags >>= \fd -> 
       openFd "fifo2" ReadOnly Nothing flags >>= \fd2 -> 
       openFd "fifo3" ReadOnly Nothing flags >>= \fd3 -> 
       openFd "fifo4" ReadOnly Nothing flags >>= \fd4 -> 
       putStrLn "Making" >>
       let
           set = fromList [fd, fd3]
           set2 = insert fd4 set
           set3 = fromList [fd, fd3]
           set4 = remove fd4 (remove fd3 (remove fd2 (remove fd set3)))
       in
         print (fd `elem` set) >> 
         print (fd2 `elem` set) >> 
         print (fd3 `elem` set) >>
         print (fd4 `elem` set) >> 
         print [fd, fd3] >>
         print (unsafeToList set) >>
         print (fd `elem` set2) >> 
         print (fd2 `elem` set2) >> 
         print (fd3 `elem` set2) >>
         print (fd4 `elem` set2) >>
         print (fd `elem` set3) >> 
         print (fd2 `elem` set3) >> 
         print (fd3 `elem` set3) >>
         print (fd4 `elem` set3) >>
         print (fd `elem` set4) >> 
         print (fd2 `elem` set4) >> 
         print (fd3 `elem` set4) >>
         print (fd4 `elem` set4)