最简单的Erlang Socket程序

最简单的Erlang Socket程序

server.erl:

 1  - module(server).
 2  - export([start / 0 ]).
 3 
 4  start()  ->
 5      {ok,Listen} = gen_tcp:listen( 2345 ,[binary,{packet, 4 },
 6                                              {reuseaddr, true },
 7                                              {active, true }]),
 8      {ok,Socket} = gen_tcp:accept(Listen),
 9      gen_tcp:close(Listen),
10      loop(Socket).
11 
12  loop(Socket)  ->
13      receive
14          {tcp,Socket,Bin}  ->
15              io:format( " Server received binary = ~p~n " ,[Bin]),
16              Str = binary_to_term(Bin),
17              io:format( " Server (unpacked) ~p~n " ,[Str]),
18              Reply =  Str  ++   " ** MLGB! " ,
19              io:format( " Server replying = ~p~n " ,[Reply]),
20              gen_tcp:send(Socket,term_to_binary(Reply)),
21              loop(Socket);
22          {tcp_closed,Socket}  ->
23              io:format( " Server socket closed~n " )
24      end.

client.erl:

 1  - module(client).
 2  - export([start / 1 ]).
 3 
 4  start(Str)  ->
 5    {ok, Socket}  =  
 6      gen_tcp:connect( " localhost " ,  2345 , [binary, {packet,  4 }]),
 7      ok  =  gen_tcp:send(Socket, term_to_binary(Str)),
 8      receive
 9        {tcp, Socket, Bin}  ->
10          io:format( " Client received binary = ~p~n " , [Bin]),
11          Val  =  binary_to_term(Bin),
12          io:format( " Client result = ~p~n " , [Val]),
13          gen_tcp:close(Socket)
14      end.

编译:

1  Eshell  >  c(server).
2  Eshell  >  c(client).

启动server:

1  Eshell  >  server:start().

启动client:

1  Eshell  > client:start("sb").

server端输出:

1 Server received binary = <<131,107,0,2,115,98>>
2 Server (unpacked) "sb"
3 Server replying = "sb** MLGB!"
4 Server socket closed

client端输出:

1 Client received binary = <<131,107,0,10,115,98,42,42,32,77,76,71,66,33>>
2 Client result = "sb** MLGB!"