Socket_server(TCP)

#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<string.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<sys/socket.h>
#include<sys/wait.h>

#define PORT 3333     //服务器监听端口号
#define BACKLOG 10    //最大同时连接请求数

int main()
{
    int sockfd;     /*监听socket*/
    int client_fd;     /*数据传送socket*/
    struct sockaddr_in my_addr;    /*本机地址信息*/
    struct sockaddr_in remote_addr; /*客户端地址信息*/
    int sin_size;
    /*
     socket(int domain,int type,int protocol)
     domain:
        AF_INET :Ipv4 协议
        AF_INET6:Ipv6 协议
        ……
     type:
        SOCK_STREAM: 字节数据流套接字
        SOCK_DGRAM: 数据包套接字
        SOCK_RAW: 原始套接字
     protocol:
        设置为 0 表示自动选择
    */
    sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd == -1)
    {
        perror("socket create error!");
        exit(1);
    }
    my_addr.sin_family = AF_INET;
    /*htons()函数把主机字节序转换成网络字节序*/
    my_addr.sin_port = htons(PORT);
    my_addr.sin_addr.s_addr = INADDR_ANY; /*????*/
    bzero(my_addr.sin_zero,8);
    /*
     int bind(int sockfd,struct sockaddr* my_addr,int addrlen)
     sockfd:
        socket()函数返回的socket描述符
     my_addr:
        指向包含本机ip及端口号等信息的sockaddr类型的指针
     addrlen:
        sockaddr结构体长度
    */
    int bindret = bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr));

    if(bindret == -1)
    {
        perror("bind error！");
        exit(1);
    }

    int listenret = listen(sockfd,BACKLOG);

    if(listenret == -1)
    {
        perror("listen error！");
        exit(1);
    }
    while(1)
    {
        sin_size = sizeof(struct sockaddr_in);

        client_fd = accept(sockfd,(struct sockaddr*)&remote_addr,&sin_size);

        if(client_fd == -1)
        {
            perror("accept error!");
            continue;
        }
        printf("receve a connect from : %s\n",inet_ntoa(remote_addr.sin_addr));

        if(!fork())
        {
            /*子进程代码段*/
            /*
             int send(int sockfd,const void *msg,int len,int flags);
            */
            int send_ret = send(client_fd,"Connected succeed!",26,0);

            if(send_ret == -1)
            {
                perror("send error!");
            }
            close(client_fd);
            exit(0);
        }

        close(client_fd);
    }

}