socket__02________accept()

inet_ntoa(addr_in param);//返回一个指针，指向ip串，失败为null
//思考，ip地址串保存在哪里？

int ret = accept(int sock,sockaddr_in *sockaddr,int len);

://len传入sockaddr_in的结构长度
//ret返回一个socket套接字，鱼客户端请求连接

注意：三次握手已经在监听过程完成
accept不含三次握手

#ifdef WIN32
#include<windows.h>
#pragma comment(lib,"ws2_32.lib")
typedef int socklen_t;
#else
#include<unistd.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>

#define closesocket close
#endif
#include<iostream>


int main()
{
#ifdef WIN32
    WSADATA wsa;
    WSAStartup(MAKEWORD(2,2),&wsa);
#endif
    int sock = socket(AF_INET,SOCK_STREAM,0);

    if (-1 == sock)
    {
        std::cout << "create socket failed" << std::endl;
        return 0;
    }

    sockaddr_in saddr;
    saddr.sin_family = AF_INET;
    saddr.sin_port = htons(8080);

//  typedef struct in_addr {
//      union {
//          struct { UCHAR s_b1, s_b2, s_b3, s_b4; } S_un_b;
//          struct { USHORT s_w1, s_w2; } S_un_w;
//          ULONG S_addr;
//      } S_un;
//#define s_addr  S_un.S_addr /* can be used for most tcp & ip code */
//#define s_host  S_un.S_un_b.s_b2    // host on imp
//#define s_net   S_un.S_un_b.s_b1    // network
//#define s_imp   S_un.S_un_w.s_w2    // imp
//#define s_impno S_un.S_un_b.s_b4    // imp #
//#define s_lh    S_un.S_un_b.s_b3    // logical host
//  } IN_ADDR, *PIN_ADDR, FAR *LPIN_ADDR;
//
//

#ifdef WIN32
    saddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
#else
    saddr.sin_addr.s_addr = inet_addr("192.168.23.130");
#endif
    int ret = bind(sock,(sockaddr*)&saddr,sizeof(saddr));
    if (0 != ret)
    {
        std::cout << "failed to bind" << std::endl;
        return -2;
    }

    std::cout << "bind port : " << ntohs(saddr.sin_port) << "success" << std::endl;

    listen(sock,20);

    sockaddr_in client;
    socklen_t len = sizeof(client);
    int retsock = accept(sock,(sockaddr*)&client,&len);
    if (-1 == retsock)
    {
        std::cout << "failed to accept" << std::endl;
        return -3;
    }

    std::cout << inet_ntoa(client.sin_addr) << std::endl;


    closesocket(sock);

    std::cin.ignore();

    return 0;
}

在linux端运行改程序
在windows端可用ssh，telnet远程连接

cmd–.>>telnet ip port