C/C++网络编程：TCP基础编程

• TCP Server（Linux）demo

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define CHECK_POINT(x, y) {if((x) < 0){printf("%s error!\n", y);}}

typedef struct sockaddr sockaddr;
typedef struct sockaddr_in sockaddr_in;
const char * ip = "127.0.0.1";
const uint16_t port = 39000;

int main()
{
    int sock, ret;
    sockaddr_in addr, peer;

    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr(ip);
    addr.sin_port = htons(39000);

    sock = socket(AF_INET, SOCK_STREAM, 0);
    
    ret = bind(sock, (sockaddr *)&addr, sizeof(addr));
    CHECK_POINT(ret, "bind");

    ret = listen(sock, 5);
    CHECK_POINT(ret, "listen");

    while(true)
    {
        printf("TCP Server Running...\n");

        socklen_t peer_len = sizeof(peer);
        ret = accept(sock, (sockaddr *)&peer, &peer_len);

        char * peer_ip = inet_ntoa(peer.sin_addr);
        uint16_t peer_port = ntohs(peer.sin_port);

        printf("accept from %s:%d connection...\n", peer_ip, peer_port);
    }

    return 0;
}

• TCP Client（Linux）demo

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
// #include <winsock2.h>
#include <unistd.h>

#define CHECK_POINT(x, y) {if((x) < 0){printf("%s error!\n", y);}}

typedef struct sockaddr sockaddr;
typedef struct sockaddr_in sockaddr_in;
const char * ip = "127.0.0.1";
const ushort port = 39000;

int main()
{
    int sock, ret;
    sockaddr_in addr;

    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr(ip);
    addr.sin_port = htons(port);

    sock = socket(AF_INET, SOCK_STREAM, 0);

    ret = connect(sock, (sockaddr *)&addr, sizeof(addr));
    CHECK_POINT(ret, "connect");

    return 0;
}

• TCP Client（Windows）demo

#include <stdio.h>
// #include <sys/socket.h>
// #include <netinet/in.h>
// #include <arpa/inet.h>
#include <winsock2.h>
#include <unistd.h>

#define CHECK_POINT(x, y) {if((x) < 0){printf("%s error!\n", y);}}

typedef struct sockaddr sockaddr;
typedef struct sockaddr_in sockaddr_in;
const char * ip = "127.0.0.1";
const USHORT port = 39000;

int main()
{
    int sock, ret;
    sockaddr_in addr;

    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr(ip);
    addr.sin_port = htons(port);

    WSADATA wsaData;
    if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
        printf("WSAStartup error!\n");

    sock = socket(AF_INET, SOCK_STREAM, 0);

    ret = connect(sock, (sockaddr *)&addr, sizeof(addr));
    CHECK_POINT(ret, "connect");

    return 0;
}