c语言实现简单的tcp服务端

功能：监听本地8888端口，接收到客户端连接请求后创建线程单独处理与客户端的交互，支持同时与多个客户端交互。

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#define PORT 8888

void *deal_client(void *args)
{
    int fd;
    int i;
    unsigned char recv_buff[1024] = {0};
    int read_len = 0;
    int send_len = 0;
    unsigned char *send_data = "hello,this is a tcp server\n";

    fd = (int) *(int *) args;
    printf("fd %d\n", fd);
    if (fd < 0)
    {
        printf("socket err\n");
        return NULL;
    }

    while (1)
    {
        memset(recv_buff, 0x00, sizeof (recv_buff));

        read_len = recv(fd, recv_buff, sizeof (recv_buff), 0);
        if (read_len < 0)
        {
            printf("recv err\n");
            close(fd);
            fd = -1;
            return NULL;
        } else if (read_len == 0)
        {
            printf("close \n");
            close(fd);
            fd = -1;
            return NULL;
        }


        printf("recv data: %s\n", recv_buff);
        //        for (i = 0; i < read_len; i++)
        //        {
        //            printf("%02x ", recv_buff[i]);
        //        }
        //        printf("\n");

        send_len = send(fd, send_data, strlen(send_data), 0);
        if (send_len <= 0)
        {
            printf("send err\n");
            close(fd);
            fd = -1;
            return NULL;
        }
    }
}

int main()
{
    //创建套接字
    int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_fd < 0)
    {
        printf("socket err\n");
        return -1;
    }
    printf("socket create success sfd=%d\n", socket_fd);

    //设置端口重用
    int resue = 1;
    if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &resue, sizeof (resue)) < 0)
    {
        printf("setsockopt SO_REUSEADDR err\n");
        return -1;
    }

    //填充服务器的地址信息结构体
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr("0.0.0.0");

    //绑定端口号
    if (bind(socket_fd, (struct sockaddr*) &sin, sizeof (sin)) < 0)
    {
        printf("bind err\n");
        return -1;
    }
    printf("bind success\n");

    //监听端口号
    if (listen(socket_fd, 5) == -1)
    {
        printf("listen err\n");
        return -1;
    }
    printf("listen success\n");

    while (1)
    {
        struct sockaddr_in cin; //存储连接成功的客户端地址
        socklen_t addrlen = sizeof (cin);
        int socket_cli = -1;

        socket_cli = accept(socket_fd, (struct sockaddr*) &cin, &addrlen);
        if (socket_cli < 0)
        {
            printf("accept err\n");
            continue;
        }
        printf("socket_cli %d\n", socket_cli);
        pthread_t tid = -1;
        pthread_create(&tid, NULL, deal_client, &socket_cli);

        usleep(1000); //注意这里必须sleep一下，不然参数传递不过去
    }
}