通过TCP | C、Windows发送文件

你好，我正在尝试将文件从服务器发送到客户端 我确实发了一条信息，它确实起了作用 但对于文件来说，它就是不起作用。。 可能是语法有问题 你知道为什么吗

客户：

#include<stdio.h>
#include<winsock2.h>
#include <stdlib.h>
#include <Windows.h>
#include <string.h>

#pragma comment(lib,"ws2_32.lib") //Winsock Library

int main()
{
    WSADATA wsa;// Struct that winsock2 has
    SOCKET s; // the socket
        size_t nRecv,nWrite;
FILE *fp;


    struct sockaddr_in server; // built-in struct
        /*struct sockaddre_in
    {
        short  sin_family; // Address Faimly (IPV4 / IPV6)
        unsigned short sin_port; // which port the data will transfer e.g htons(80)
        struct in_addr sin_addr;
        char sin_zero[8];
    }server;*/
    char *message , server_reply[2000]; // the data we send and the server reply
    int recv_size; // the size of the recived data

    // ------------------------------------------Checking the DLL verision --------------------------------------- //


    // - First we have to initialising the winsock dll to see if there are any errors while loading it //

    printf("\nInitialising Winsock...");
    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)  // if there are any error WSAStartup will return non-zero value .
    {
        printf("Failed. Error Code : %d",WSAGetLastError());
        return 1;
    }

    printf("Step 1 : Initialised.\n");

        // ---------------------------------------------Creating the Socket ----------------------------------------- //

    // - AF_INET - Address Family (IP version , This case is IPV4)
    //- SOCK_STREAM - this is the type , what type of communction would be this case is TCP Which could STREAM
    // - 0 is the TCP protocol.

    if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET) // if the returned value of socket() INVALID_SOCKET
    {
        printf("Could not create socket : %d" , WSAGetLastError());
        return 1;
    }

    printf("Step 2 : Socket created.\n");

         // --------------------------------------- Connecting to the SERVER ----------------------------------------//

    // inet_addr() converting a IP to a long format .

    server.sin_addr.s_addr = inet_addr("10.0.0.4"); // <-- here we have to insert the ip of the server
    server.sin_family = AF_INET; // IPV4 in this case .
    server.sin_port = htons( 9999 ); // the wanted port (HTML = 80)

    //Connect to remote server
    if (connect(s , (struct sockaddr *)&server , sizeof(server)) < 0)//casing server value to sockaddr struct
    {
        puts("connect error");
        return 1;
    }

    puts("Step 3 : Connected");

//-----------------------------------------------------Recieve from the Server ------------------------------//

fp = fopen("output.txt", "wb");
    if (fp == NULL)
    {
        printf("File not found!\n");
        return 1;
    }
    else
    {
        printf("created file output.txt\n");
    }  


while (recv_size = recv(s, server_reply, 256, 0))
{
    if (recv_size == SOCKET_ERROR) {
        puts("recv failed");
        return 1;
    }
    else
    {
         nWrite = fwrite(server_reply, sizeof(char), recv_size, fp);
    }

if(nWrite<=0)
{
printf("error while reading the file");
return 1;
}
else{
puts("Step 4 :Reply received\n");
}

}



    return 0;
}

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#pragma注释（lib，“ws2_32.lib”）//Winsock库
int main（）
{
WSADATA wsa；//winsock2具有的结构
套接字s；//套接字
尺寸为nRecv，nWrite；
文件*fp；
服务器中的struct sockaddr_；//内置结构
/*结构sockaddre_in
{
短sinu系列；//地址Faimly（IPV4/IPV6）
无符号短单端口；//数据将传输到哪个端口，例如htons（80）
结构输入地址sin地址；
char sin_zero[8]；
}服务器*/
char*message，server_reply[2000]；//我们发送的数据和服务器回复
int recv_size；//接收数据的大小
//---------------------------------------正在检查DLL验证--------------------//
//-首先，我们必须初始化winsock dll，查看加载时是否有任何错误//
printf（“\n初始化Winsock…”）；
if（WSAStartup（MAKEWORD（2,2），&wsa）！=0）//如果有任何错误，WSAStartup将返回非零值。
{
printf（“失败。错误代码：%d”，WSAGetLastError（））；
返回1；
}
printf（“步骤1：初始化。\n”）；
//---------------------------------------------------创建套接字--------------------------------//
//-AF_INET-地址系列（IP版本，本例为IPV4）
//-SOCK_STREAM-这是一种类型，什么类型的通信会是这种情况下的TCP可以流
//-0是TCP协议。
if（（s=socket（AF\u INET，SOCK\u STREAM，0））==无效的\u socket）//如果socket（）的返回值无效的\u socket
{
printf（“无法创建套接字：%d”，WSAGetLastError（））；
返回1；
}
printf（“步骤2：创建套接字。\n”）；
//------------------------------------连接到服务器----------------------------------------//
//inet_addr（）将IP转换为长格式。
server.sin_addr.s_addr=inet_addr（“10.0.0.4”）；//客户端：'nWrite=fwrite（server_reply，sizeof（char），nRecv，fp）；'-nRecv未初始化。你是说'recv_size'？还有，几乎不可避免的问题：你在自己的调试工作中发现了什么？为什么海报不告诉我们这些东西？@MartinJames，是的，对不起。调试错误：表达式（steam！=NULL）。读取时出错。无法读取文件
#include<io.h>
#include<stdio.h>
#include<winsock2.h>

#pragma comment(lib,"ws2_32.lib") //Winsock Library

int main()
{

        File *fp;
    WSADATA wsa;
    SOCKET s , new_socket;
    struct sockaddr_in server , client;
    int c;
    char message[200],TheData[256];
        size_t nRead,nSent

    printf("\nInitialising Winsock...");
    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
    {
        printf("Failed. Error Code : %d",WSAGetLastError());
        return 1;
    }

    printf("Initialised.\n");

    //Create a socket
    if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
    {
        printf("Could not create socket : %d" , WSAGetLastError());
    }

    printf("Socket created.\n");

    //Prepare the sockaddr_in structure
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = inet_addr("10.0.0.4");
    server.sin_port = htons( 9999 );

    //Bind
    if( bind(s ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
    {
        printf("Bind failed with error code : %d" , WSAGetLastError());
        return 1;
    }

    puts("Bind done");

    //Listen to incoming connections
    listen(s , 3);

    //Accept and incoming connection
    puts("Waiting for incoming connections...");

    c = sizeof(struct sockaddr_in);

   while ((new_socket = accept(s , (struct sockaddr *)&client, &c)) != INVALID_SOCKET) {
    printf ("Server: ");

    pf = fopen("input.txt", "rb");

    while (!feof(pf))
    {
        nRead = fread(TheData, sizeof(char), 256, pf);
        if (nRead <= 0)
{
            printf("ERROR reading file");
                return 1;
}
        while (nRead > 0)
        {
            nSent = send(new_socket, TheData, nRead, 0);
            if (nSent < 0)
            {

                    printf("ERROR sending from socket = %d\n", WSAGetLastError());
                    return 1;

            }
            if (nSent == 0)
{
                printf("DISCONNECTED writing to socket");
                return 1;
}

}


    closesocket(s);
    WSACleanup();

    return 0;
}