TCP/IP 多進程服務端

echo_server.c

#include <stdio.h>
#include <signal.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 1024

void read_childproc(int sig)
{
    pid_t pid;
    int status;

    pid = waitpid(-1, &status, WNOHANG);
    printf("removed proc id: %d\n", pid);
}

int main()
{

    //註冊子進程信號
    struct sigaction act;
    act.sa_sigaction = read_childproc;
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    sigaction(SIGCHLD, &act, 0);

    int serv_sock = socket(PF_INET, SOCK_STREAM, 0);

    //初始化地址
    struct sockaddr_in serv_addr;
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(9200);

    if (bind(serv_sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1)
    {
        printf("綁定地址失敗 \n");
        exit(1);
    }

    if (listen(serv_sock, 5) == 1)
    {
        printf("綁定端口失敗 \n");
        exit(1);
    }

    ////////接收請求///////////
    struct sockaddr_in clnt_adr;
    int clnt_sock, adr_sz, str_len;
    pid_t pid;
    char buf[BUF_SIZE];

    while (1)
    {
        adr_sz = sizeof(clnt_adr);
        clnt_sock = accept(serv_sock, (struct sockaddr *)&clnt_adr, &adr_sz);
        if (clnt_sock == -1)
        {
            continue;
        }
        else
        {
            puts("new client connected...");
        }

        pid = fork();
        if (pid == -1)
        {
            puts("-1 -1 -1");
            close(clnt_sock);
            continue;
        }

        //子進程處理
        if (pid == 0)
        {
            //關閉複製到的父文件號
            close(serv_sock);
            while ((str_len = read(clnt_sock, buf, BUF_SIZE)) != 0)
                write(clnt_sock, buf, str_len);
            
            close(clnt_sock);
            puts("子進程受理");
            //正常退出子進程
            return 0;
        }
        else
        {
            puts("父進程不處理 clnt_sock");
            close(clnt_sock);
        }
    }

    close(serv_sock);
    return 0;
}
複製代碼

echo_client.c

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define BUF_SIZE 5

int main(int argc, char *argv[])
{
    char message[BUF_SIZE];
    int str_len, recv_len, recv_cnt, i;

    struct sockaddr_in serv_addr, clnt_addr;

    int serv_sock = socket(PF_INET, SOCK_STREAM, 0);
    if (serv_sock == -1)
    {
        printf("socket() error");
        exit(1);
    }

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    serv_addr.sin_port = htons(9200);

    if (connect(serv_sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1)
    {
        printf("connect() error");
        exit(1);
    }

    while (1)
    {
        fputs("請輸入您的信息,按Q鍵退出\n", stdout);
        fgets(message, 1024, stdin);

        //由於fgets會保留輸入中換行符,故判斷加\n
        if (!strcmp(message, "q\n") || !strcmp(message, "Q\n"))
        {
            break;
        }

        write(serv_sock, message, strlen(message));
        str_len = read(serv_sock, message, BUF_SIZE);

        printf("Message from server: %s\n", message);
    }

    close(serv_sock);
    return 0;
}
複製代碼