Question

我想通过套接字将文件从Linux服务器发送到Windows客户端，问题是我收到的字节多于发送的字节数。

服务器代码--------------------------------------------- -

if (resultEnviarLongitud = send(ClientSocket,GotFileSize.c_str(),1024,0)<0){
    cout<<endl<<"Error mandando la longitud! "<<endl;
}
rewind(fs);

while ((len = fread(Buffer,1,1024, fs)) > 0)
{
    if((resultEnviar = send(ClientSocket,Buffer,1024,0)) < 0){
        printf("ERROR: Failed to send file %s.\n", nombreArchivoADescargar.c_str());
        break;
    }
    sumEnviada+=len;
}

send(ClientSocket,"Hi",sizeof(Buffer),0);


cout<<"Bytes enviados: "<<sumEnviada<<endl;
strcpy(data, "");

cout<<endl<<"ARCHIVO MANDADO EXITOSAMENTE!"<<endl;
rutaArchivoADescargar.clear();

客户端代码-----------------------------------------

if (resultRecibirLongitud = recv(sock, Buffer, sizeof(Buffer), 0) > 0)
{
    LongitudArchivo = atoi(Buffer);
    cout<<endl<<"Longitud Archivo a Recibir: " <<LongitudArchivo<<endl; 
}

FILE *fp=fopen("imagen.jpg","wb");
if (fp==NULL){
    cout<<"Error al crear archivo."<<endl;
}else{
    bzero(Buffer2, 1024); 
    int fr_block_sz = 0;
    int contador=0;

    //shutdown(sock, SD_SEND); I HAVE TO USE IT?

    while((fr_block_sz = recv(sock, Buffer2, 1024, 0)) >= 0) 
    {
        if (fr_block_sz == 0) break;
        if ( strcmp (Buffer,"Hi") == 0) break;
        int write_sz = fwrite(Buffer2, 1, 1024, fp);
        if(write_sz < fr_block_sz)
        {
            printf("File write failed on server.\n");
        }
        bzero(Buffer2, 1024);
        contador+=fr_block_sz;
        if (contador >= LongitudArchivo)break;
        bzero(Buffer2, 1024); 
    }
    cout<<endl<<"Numero de bytes recibidos: "<<contador<<endl<<endl;
    if(fr_block_sz < 0)
    {
        printf("Error receiving file from client to server.\n");
    }
    printf("Ok received from client!\n");
    fclose(fp); 
}

谢谢，

Answer 1

while ((len = fread(Buffer,1,1024, fs)) > 0)
{
    if((resultEnviar = send(ClientSocket,Buffer,1024,0)) < 0)

您的一个问题是，即使您fread字节较少，也始终发送1024字节的缓冲区。（请注意，1348656向上舍入到最接近的1024的倍数是1349632.）

所以，在写作方面你需要类似的东西：

while ((len = fread(Buffer,1,1024, fs)) > 0)
{
    if((resultEnviar = send(ClientSocket,Buffer,len,0)) < 0)

并且在阅读方面你需要类似的东西：

while((fr_block_sz = recv(sock, Buffer2, 1024, 0)) >= 0) 
{
    // ...
    int write_sz = fwrite(Buffer2, 1, fr_block_sz, fp);

您的初始send也存在问题，因为您总是发送1024个字节而不检查这是c_str返回的实际长度。

接收比发送的C ++更多的字节

1 个答案: