网络编程：TCP传输

TCP传输

1.TCP实现文件传输

服务器端 server.cpp：

#include 
#include 
#include 
#pragma comment (lib, "ws2_32.lib")  //加载 ws2_32.dll

#define BUF_SIZE 1024

int main(){
    //先检查文件是否存在
    char *filename = "D:\\send.avi";  //文件名
    FILE *fp = fopen(filename, "rb");  //以二进制方式打开文件
    if(fp == NULL){
        printf("Cannot open file, press any key to exit!\n");
        system("pause");
        exit(0);
    }

    WSADATA wsaData;
    WSAStartup( MAKEWORD(2, 2), &wsaData);
    SOCKET servSock = socket(AF_INET, SOCK_STREAM, 0);

    sockaddr_in sockAddr;
    memset(&sockAddr, 0, sizeof(sockAddr));
    sockAddr.sin_family = PF_INET;
    sockAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    sockAddr.sin_port = htons(1234);
    bind(servSock, (SOCKADDR*)&sockAddr, sizeof(SOCKADDR));
    listen(servSock, 20);

    SOCKADDR clntAddr;
    int nSize = sizeof(SOCKADDR);
    SOCKET clntSock = accept(servSock, (SOCKADDR*)&clntAddr, &nSize);

    //循环发送数据，直到文件结尾
    char buffer[BUF_SIZE] = {0};  //缓冲区
    int nCount;
    while( (nCount = fread(buffer, 1, BUF_SIZE, fp)) > 0 ){
        send(clntSock, buffer, nCount, 0);
    }

    shutdown(clntSock, SD_SEND);  //文件读取完毕，断开输出流，向客户端发送FIN包
    recv(clntSock, buffer, BUF_SIZE, 0);  //阻塞，等待客户端接收完毕

    fclose(fp);
    closesocket(clntSock);
    closesocket(servSock);
    WSACleanup();

    system("pause");
    return 0;
}

客户端代码client.cpp：

#include 
#include 
#include 
#pragma comment(lib, "ws2_32.lib")

#define BUF_SIZE 1024

int main(){
    //先输入文件名，看文件是否能创建成功
    char filename[100] = {0};  //文件名
    printf("Input filename to save: ");
    gets(filename);
    FILE *fp = fopen(filename, "wb");  //以二进制方式打开（创建）文件
    if(fp == NULL){
        printf("Cannot open file, press any key to exit!\n");
        system("pause");
        exit(0);
    }

    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);
    SOCKET sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);

    sockaddr_in sockAddr;
    memset(&sockAddr, 0, sizeof(sockAddr));
    sockAddr.sin_family = PF_INET;
    sockAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    sockAddr.sin_port = htons(1234);
    connect(sock, (SOCKADDR*)&sockAddr, sizeof(SOCKADDR));

    //循环接收数据，直到文件传输完毕
    char buffer[BUF_SIZE] = {0};  //文件缓冲区
    int nCount;
    while( (nCount = recv(sock, buffer, BUF_SIZE, 0)) > 0 ){
        fwrite(buffer, nCount, 1, fp);
    }
    puts("File transfer success!");

    //文件接收完毕后直接关闭套接字，无需调用shutdown()
    fclose(fp);
    closesocket(sock);
    WSACleanup();
    system("pause");
    return 0;
}