Question

我是尝试使用Unix套接字进行编程的新手，并努力让简单的服务器正常工作。我喜欢这样保持运行并打印收到的消息，而是打印出第一条消息然后退出。取决于network和bytestring。

module Main where

import Network.Socket hiding (send, sendTo, recv, recvFrom)
import Network.Socket.ByteString
import qualified Data.ByteString.Char8 as C
import Control.Monad

main :: IO ()
main = withSocketsDo $ do
       sock <- socket AF_UNIX Stream 0 -- and try UDP?
       bind sock (SockAddrUnix "/tmp/test_sock.ipc")
       listen sock maxListenQueue -- TODO is maxListenQueue what we want?
       (conn, _) <- accept sock
       talk conn
       close conn
       close sock
       putStrLn "DONE"

    where
      talk :: Socket -> IO ()
      talk conn =
          do msg <- recv conn 1024
             unless (C.null msg) $ do
               C.putStrLn msg 
               talk conn

我正在使用socat进行测试，我也不知道该如何使用：

echo "FOOOOO" | socat - UNIX-CONNECT:/tmp/test_sock.ipc

关于haskell代码的任何指针，以及我可能对unix套接字的误解都会有所帮助。

编辑使用Datagram代替Stream我可以获得更多或更少的内容：

main :: IO（） main = withSocketsDo $ do sock＆lt; - socket AF_UNIX数据报0 - 并尝试UDP？绑定袜子（SockAddrUnix＆＃34; /tmp/test_sock.ipc"） - 对于数据报：说袜子关闭袜子 putStrLn＆＃34; DONE＆＃34;

where
  talk :: Socket -> IO ()
  talk conn =
      do msg <- recv conn 1024
         unless (C.null msg) $ do
           C.putStrLn msg 
           talk conn

我可以成功测试：

echo "FOOOOO" | socat - UNIX-SENDTO:/tmp/test_sock.ipc

我认为无论如何我对数据报套接字感兴趣，但是如果有人想向我解释这些内容，我会将其保留为开放状态。

Answer 1

您的代码仅运行＆＃34;接受＆＃34;一次，所以它只能处理一个连接。如果你想处理多个连接，那么＆＃34;接受＆＃34;部分必须重复，而不仅仅是＆＃34; recv＆＃34;一部分。

module Main where

import Network.Socket hiding (send, sendTo, recv, recvFrom)
import Network.Socket.ByteString
import qualified Data.ByteString.Char8 as C
import Control.Monad

main :: IO ()
main = withSocketsDo $ do
       sock <- socket AF_UNIX Stream 0 -- and try UDP?
       bind sock (SockAddrUnix "/tmp/test_sock.ipc")
       listen sock maxListenQueue -- TODO is maxListenQueue what we want?
       go sock
       close conn
       close sock
       putStrLn "DONE"

    where
      go sock = do
        (conn,_) <- accept sock
        talk conn
        go sock
      talk :: Socket -> IO ()
      talk conn =
          do msg <- recv conn 1024
             unless (C.null msg) $ do
               C.putStrLn msg 
               talk conn

简单的unix域套接字服务器

1 个答案: