Recently I developed Erlang, and I was speechless about its string handling ability, so I decided to combine it with python to create a powerful distributed system, and when I need system-level development in the future, I'll put C++/C into the mix.
First refer to the official Erlang documentation and /?tag=erlang and /computer/port-howto/ .
It took nearly 24 hours of study to completely solve the problem. The name is town, which means a marketplace in English, and also represents the exchange and interaction of various languages here). )
-module(town).
-behaviour(gen_server).
%% API
-export([start/0,combine/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-record(state, {port}).
start() ->
gen_server:start_link({global, ?MODULE}, ?MODULE, [], []).
stop() ->
gen_server:cast(?SERVER, stop).
init([]) ->
process_flag(trap_exit, true),
Port = open_port({spawn, "python -u /home/freefis/Desktop/"},[stream,{line, 1024}]),
{ok, #state{port = Port}}.
handle_call({combine,String}, _From, #state{port = Port} = State) ->
port_command(Port,String),
receive
{Port,{data,{_Flag,Data}}} ->
io:format("receiving:~p~n",[Data]),
sleep(2000),
{reply, Data, Port}
end.
handle_cast(stop, State) ->
{stop, normal, State};
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info(Info, State) ->
{noreply,State}.
terminate(_Reason, Port) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%--------------------------------------------------------------------
%%% Internal ---------------------------------------------------------
combine(_String) ->
start(),
String = list_to_binary("combine|"++_String++"\n"),
gen_server:call(?SERVER,{combine,String},infinity),
stop().
This is a Python script When town:combine("sentence1+sentence2") is executed in erlang, a python script is started in the background, processed and returned to Erlang with the result. sentence1sentence2, and then exits.
import sys
def handle(_string):
if _string.startswith("combine|"):
string = "".join( _string[8:].split(","))
return string
"""waiting for input """
while 1:
# Recv. Binary Stream as Standard IN
_stream = ()
if not _stream: break
# Scheme, Turn into Formal String
inString = _stream.strip("\r\n")
# handle String
outString = handle(inString)
# send to port as Standart OUT
("%s\n" % (outString,))
(0)
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