[Haskell-beginners] Haskell network sample

[Bob Ippolito]

Not sure why you're having issues, I just tried it on GHC 7.6.3 on Fedora
20 and it worked fine there as well (both with runhaskell or compiled with
-O).

I might start adding putStrLn statements to the code to see where it's
unexpectedly blocking, or perhaps use 127.0.0.1 instead of "localhost" in
case the issue is a DNS misconfiguration.



On Tue, May 20, 2014 at 10:51 PM, yang.zhao <hckjsnzf at gmail.com> wrote:

> thanks for your replay.
> i run the two program in two different teriminal for sure.
>
> it works for you?
> but why can't run well on my computer.
>
> make me creazy....
>
>
> 2014-05-21 13:47 GMT+08:00 Bob Ippolito <bob at redivi.com>:
>
> How precisely are you trying to run the client? Are you typing it in to
>> the same terminal? If so, then the client is never actually started,
>> because when you type ./cli the input is going to ./serv and not the shell.
>> Try running the client in a separate terminal.
>>
>> It works for me here on Mac OS X 10.9.2 with GHC 7.8.2.
>>
>>
>> On Tue, May 20, 2014 at 10:42 PM, yang.zhao <hckjsnzf at gmail.com> wrote:
>>
>>> hi guys,
>>> I'm newbie, just begin to learn Haskell.
>>> now i write a very simple server and client .
>>>
>>> Server:
>>> import Control.Concurrent
>>> import System.IO
>>> import Network
>>>
>>> port :: Int
>>> port = 1234
>>>
>>> main :: IO ()
>>> main = withSocketsDo $ do
>>>     s <- listenOn $ PortNumber $ fromIntegral port
>>>     (h, _, _) <- accept s
>>>
>>>     sline <- hGetLine h
>>>     hPutStrLn h sline
>>>     putStrLn $ "send "++sline
>>>     threadDelay 1000000
>>>
>>>     hClose h
>>>     sClose s
>>>
>>> Client :
>>> import System.IO
>>> import Network
>>>
>>> port :: Int
>>> port = 1234
>>>
>>> main :: IO ()
>>> main = withSocketsDo $ do
>>>     h <- connectTo "localhost" $ PortNumber $ fromIntegral port
>>>     hPutStrLn h "hello"
>>>     bs <- hGetContents h
>>>     putStrLn bs
>>>     hClose h
>>>
>>>
>>> And, it doesn't work now . I run ./serv , then run ./cli , they will
>>> block all the time.
>>> but,  when i run ./serv, and telnet localhost 1234 in another terminal,
>>> it works fine.
>>> so i don't know what's the wrong with my code.
>>> anybody can tell me about my problem?
>>>
>>> os is Debian 7,  haskell-platform  2012.2.0.0
>>>
>>> thanks a lot!!!
>>> --
>>> K.I.S.S.
>>>
>>> _______________________________________________
>>> Beginners mailing list
>>> Beginners at haskell.org
>>> http://www.haskell.org/mailman/listinfo/beginners
>>>
>>>
>>
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>
>
> --
> K.I.S.S.
>
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