简易TCP C/S通信

蓝牙先生2025-11-28 22:22
效果
s.c
复制代码
root@TTT:~# cat s.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <assert.h>


int main(int argc, char *argv[])
{
        int fd = -1;
        int ret = -1;
        int opt = 1;
        struct sockaddr_in addr;
        struct sockaddr_in client;
        socklen_t len = 0;
        pid_t pid = -1;


        addr.sin_family = AF_INET;
        addr.sin_port = htons(7000);
        addr.sin_addr.s_addr = inet_addr("0.0.0.0");

        client.sin_family = AF_INET;
        client.sin_port = htons(7001);
        client.sin_addr.s_addr = inet_addr(argv[1]);

        pid = fork();
        if (pid == -1)
        {
                perror("fork:");
        }
        else if (pid > 0)
        {
                fd = socket(AF_INET, SOCK_STREAM, 0);
                setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

                printf("Server# set server IP %s Port %d\n", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
                ret = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
                assert(ret == 0);

                ret = listen(fd, 6);
                assert(ret == 0);

                printf("Server# start accept\n");
                len = sizeof(client);
                ret = accept(fd, (struct sockaddr *)&client, &len);
                printf("Server# accept IP %s Port %d connected\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
                close(ret);
                close(fd);
        }
        else
        {
                usleep(20000);
                fd = socket(AF_INET, SOCK_STREAM, 0);
                setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
                assert(fd != -1);

                printf("Client# set client IP %s Port %d\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
                ret = bind(fd, (struct sockaddr *)&client, sizeof(client));
                assert(ret == 0);

                printf("Client# connect to IP %s Port %d\n", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
                ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
                close(fd);
        }
        usleep(2000);

        return 0;
}