C/C++网络编程9——多进程服务器端实现

#include <iostream>
#include <unistd.h>
#include <cstdlib>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <signal.h>
#include <string>

using namespace std;

const int BUFFER_SIZE = 1024;

void read_child_proc(int sig)
{
    int status = 0;
    waitpid(-1, &status, WNOHANG);
}

int deal_error(string error_msg)
{
    cout << error_msg << endl;
    return 0;
}

int main()
{
    // 创建套接字
    int ser_sock = socket(PF_INET, SOCK_STREAM, 0);
    if (ser_sock == -1) {
        return deal_error("socket() failed");
    }

    // 套接字绑定ip及端口号
    sockaddr_in ser_addr;
    ser_addr.sin_family = AF_INET;
    ser_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    ser_addr.sin_port = htons(9999);
    if (bind(ser_sock, (sockaddr *)&ser_addr, sizeof(ser_addr)) == -1) {
        close(ser_sock);
        return deal_error("bind() failed");
    }

    // 开始监听
    if (listen(ser_sock, 5) == -1) {
        close(ser_sock);
        return deal_error("listen() failed");
    }

    // 注册信号
    signal(SIGCHLD, read_child_proc);   // 子进程执行结束信号注册，防止僵尸进程产生
    signal(SIGINT, exit);               // CTRL+C信号注册，退出程序

    while(1) {
        sockaddr_in clnt_addr;
        socklen_t addr_length = sizeof(clnt_addr);
        int clnt_sock = accept(ser_sock, (sockaddr *)&clnt_addr, &addr_length);
        if (clnt_sock == -1) {
            continue;
        }

        cout << "new client connected: " << clnt_sock << endl;
        pid_t pid = fork();
        if (pid < 0) {
            continue;
        } else if (pid == 0) {  // 子进程
            close(ser_sock);
            char message[BUFFER_SIZE];
            int str_len = read(clnt_sock, message, BUFFER_SIZE-1);
            if (str_len > 0) {
                message[str_len] = '\0';
                cout << message << endl;
            }
            close(clnt_sock);
            sleep(60);
            return 0;
        } else {    // 父进程
            close(clnt_sock);
        }
    }

    close(ser_sock);
    return 0;
}