编写简单的消息发布器与订阅器，消息由浮点数和字符串两种数据类型组成，要求发布器用C++编写，订阅器用python编写

发布器(C++)代码如下：

#include <iostream>
#include <string>
#include <vector>
#include <cstring>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>

using namespace std;

struct msgbuf {
    long mtype;
    char mtext[1024];
};

int main() {
    key_t key = ftok("message_queue", 1);
    int msgid = msgget(key, IPC_CREAT | 0666);
    if (msgid == -1) {
        cerr << "Error creating message queue" << endl;
        return -1;
    }

    while (true) {
        double num;
        string str;
        cout << "Enter a number or a string: ";
        if (cin >> num) {
            msgbuf buf;
            buf.mtype = 1;
            memcpy(buf.mtext, &num, sizeof(num));
            msgsnd(msgid, &buf, sizeof(num), 0);
        } else {
            cin.clear();
            cin.ignore();
            getline(cin, str);
            msgbuf buf;
            buf.mtype = 2;
            strcpy(buf.mtext, str.c_str());
            msgsnd(msgid, &buf, str.size() + 1, 0);
        }
    }

    return 0;
}

订阅器(python)代码如下：

import struct
import sys
import os
import time
from ctypes import *
from numpy import *

class msgbuf(Structure):
    _fields_ = [
        ("mtype", c_long),
        ("mtext", c_char * 1024)
    ]

def main():
    key = os.ftok("message_queue", 1)
    msgid = os.msgget(key, 0666)
    if msgid == -1:
        print("Error creating message queue")
        return -1

    while True:
        buf = msgbuf()
        if os.msgrcv(msgid, byref(buf), sizeof(double), 1, os.MSG_NOERROR | os.IPC_NOWAIT) != -1:
            num = struct.unpack('d', buf.mtext)[0]
            print(f"Received number: {num}")
        if os.msgrcv(msgid, byref(buf), sizeof(buf.mtext), 2, os.MSG_NOERROR | os.IPC_NOWAIT) != -1:
            str_ = buf.mtext.decode('utf-8')
            print(f"Received string: {str_}")
        time.sleep(0.5)

if __name__ == '__main__':
    main()

这两个程序需要在同一个操作系统下运行。发布器程序会等待用户输入消息，如果是浮点数则发送消息类型为1的消息，如果是字符串则发送消息类型为2的消息。订阅器程序会不断接收消息队列中的消息，如果消息类型为1，则按照浮点数解析消息并输出；如果消息类型为2，则按照字符串解析消息并输出。