lua zmq及socket通信

ZMQ在线docs：http://api.zeromq.org/2-1-3:_start

1，序言，zmq 作为一种通信比较好，快捷的方式，越来越多的开发者使用。

这里提供一个简单的例子来叙述lua_zmq的通信方式：案例是在Mac电脑编写 
1，先说zmq中req和rep方式，rep 作为服务端，req作为请求端，req只有先收到req的请求后，才会发消息回复，同理，req只有发送请求后，才会得到rep的消息相应。流程不可变， 
上代码： 
服务端rep:
 

require "zhelpers"
local zmq = require "lzmq"  -- 获取zmq的安装包
local context = zmq.context()   -- 创建一个ZMQ 上下文  ，
local publisher, err = context:socket{zmq.REP, bind = "tcp://*:5025"}  -- 调用套接字  服务端将套接字绑定在端口5025  
zassert(publisher, err)   -- 开始等待响应 发出应答 如此循环
--  客户端是发送请求 并等待服务端的应答
local y = 0
while y>=0 do 
    local x = "This is a zmq test!"
    y = y + 1
    local ret = zassert(publisher:recv())
    print(y.."rep recv"..ret)
    sleep(1)
    zassert(publisher:send(x))
    -- print(y..":"..x)
end

客户端 req:

---------------------------------------req------------------------------------
require "zhelpers"
local zmq = require "lzmq"
local context = zmq.context();
local requester,err = context:socket{zmq.REQ,connect = "tcp://localhost:5025"}
zassert(requester,err)
for i = 1,10 do
    -- print("hello world")
    zassert(requester:send("hello"));
    local ret = requester:recv()
    print("req recv==="..ret)
end

2,方式2 zmq中的Sub和Pub,发布和订阅式，Pub可以发布许多消息给不同的用户，Sub通过filter 筛选自 己所需要的内容：
pub端：

require "zhelpers"
local zmq = require "lzmq"  -- 获取zmq的安装包
local context = zmq.context()   -- 创建一个ZMQ 上下文  ，
local publisher, err = context:socket{zmq.PUB, bind = "tcp://*:7002"}  -- 调用套接字  服务端将套接字绑定在端口6801  
zassert(publisher, err)   -- 开始等待响应 发出应答 如此循环
--  客户端是发送请求 并等待服务端的应答
local y = 0
while y>=0 do 
    local x = "This is a zmq test"
    local xx = "This is a zmq test too"
    local xxx = "This is a zmq test too too"
    y = y + 1
    -- local ret = zassert(publisher:recv())
    -- print(y.."rep recv"..ret)
    sleep(1)
    zassert(publisher:send(x))
    zassert(publisher:send(xx))
    zassert(publisher:send(xxx))
    sleep(1)
    print(y..":"..x..xx..xx)
end

sub端

--------------------------SUB-------------------

SUB会过滤PUB来得消息，由filter来定义数据格式
local filter =""
printf("Collecting updates from weather server ...\n")
local context = zmq.context()
local subscriber, err = context:socket{zmq.SUB,
  -- subscribe = filter;
  -- connect   = "tcp://172.15.2.4:6000";
  connect = "tcp://*:7002";
}
zassert(subscriber,err)
print(subscriber)
local update_nbr, total_temp = 100, 0
-- for i = 1, update_nbr do
while(1) do
    print("~~~~~~~~~~~")
    local message = subscriber:recv()
    -- local y = {}
    -- y = string.split(message,%s)
    -- print(y..":"..#y)
    local x = ""
    local table1 = {}
    for name1 in string.gmatch(message,"([%d]*)%s+([-]?[%d-]*)%s+([-]?[%d-]*)") do 
        table.insert(table1.name1)
        print(name1)
    end
    for i=1,7 do
        -- x = x..table1[i]..","
        print(i)
        print(table1[i])
    end
    -- for name2 in string.gmatch(message,"title_name %w+") do 
    --  print(name2)
    --  x = x..","..name2
    -- end
    print(x)
    print(total_temp.."-> "..message)
    total_temp = total_temp + 1
end

3，lua 中的socket通信，案例中只有发送以及接受消息，并没有回复的设置，代码后续完善： 
socket 通过绑定一个IP地址，端口号，来实现两台机子之间的通信过程。  
服务端Server:

    -- server.lua
local socket = require("socket")

-- local host = "127.0.0.1"
local host = "192.168.0.100"
local port = "12346"
local server = assert(socket.bind(host, port, 1024))
server:settimeout(0)
local client_tab = {}
local conn_count = 0

print("Server Start " .. host .. ":" .. port) 

while 1 do
    local conn = server:accept()
    if conn then
        conn_count = conn_count + 1
        client_tab[conn_count] = conn
        print("A client successfully connect!") 
    end

    for conn_count, client in pairs(client_tab) do
        local recvt, sendt, status = socket.select({client}, nil, 1)
        if #recvt > 0 then
            local receive, receive_status = client:receive()
            if receive_status ~= "closed" then
                if receive then
                    assert(client:send("Client " .. conn_count .. " Send : "))
                    assert(client:send(receive .. "\n"))
                    print("Receive Client " .. conn_count .. " : ", receive)   
                end
            else
                table.remove(client_tab, conn_count) 
                client:close() 
                print("Client " .. conn_count .. " disconnect!") 
            end
        end

    end
end

客户端Client: 
– client.lua

local socket = require("socket")

local host = "192.168.0.100"
local port = "12346"
local sock = assert(socket.connect(host, port))
sock:settimeout(0)

print("Press enter after input something:")

local input, recvt, sendt, status
while true do
    input = io.read()
    if #input > 0 then
        assert(sock:send(input .. "\n"))
    end

    recvt, sendt, status = socket.select({sock}, nil, 1)
    while #recvt > 0 do
        local response, receive_status = sock:receive()
        if receive_status ~= "closed" then
            if response then
                print(response)
                recvt, sendt, status = socket.select({sock}, nil, 1)
            end
        else
            break
        end
    end
end