I'm making a program that copies a file from client to server. I have to send the length of the file to the server before copying. Both of the programs work fine, until I add int sizeFile = getSizeFile(originalFile); in the client part of my program. All of a sudden (after I add the function) the while() loop in my server gets stuck on recv(). And the while() in my client just loops once and then breaks.

Why does my program work fine until I add the getSizeFile() function and how can I solve it?

function:

int getSizeFile(FILE* file)
{
    // get file size
    FILE *f = file;
    fseek(f, 0L, SEEK_END);
    int sizeFile = ftell(f);
    return sizeFile;
}

server:

char ch[70];
printf("where do you want to save it(full path   name): ");
scanf_s("%s", ch, 70);

char c[70];
printf("which file you want to copy(full path   name): ");
scanf_s("%s", c, 70);

r = send(s, c, 70, 0); // B
if (r == SOCKET_ERROR)
{
    printf("2 error: %d\n", WSAGetLastError);
}

FILE* copyFile;
fopen_s(&copyFile, ch, "wb");
if (copyFile == NULL)
{
    printf("Error opening file\n");
}

char buf[BUFSIZE];
size_t size = BUFSIZE;
int counter = 0;

while (1)
    {
        int res = recv(s, buf, BUFSIZE, 0);
        if (res == SOCKET_ERROR)
    {
        printf("3 error %d\n", WSAGetLastError);
        break;
    }
    size = fwrite(buf, 1, res, copyFile);
    printf("size: %d\n", size);
    printf("res: %d\n", res);
    counter  ;
    printf("counter: %d\n", counter);
}
fclose(copyFile);

client:

    char c[70];
    res = recv(ClientSocket, c, 70, 0); // B
    if (res == SOCKET_ERROR)
    {
        printf("Server disconeccted\n");
        break;
    }
                
    FILE* originalFile;
    fopen_s(&originalFile, c, "rb");
    if (originalFile == NULL)
    {
        printf("Error opening file\n");
    }

    char buf[BUFSIZE];
    size_t size = BUFSIZE;
    int counter = 0;

    int sizeFile = getSizeFile(originalFile); // <-- this one

    while (size == BUFSIZE)
    {
    size = fread(buf, 1, BUFSIZE, originalFile);
    int r = send(ClientSocket, buf, size, 0);
    if (r == SOCKET_ERROR)
    {
        printf("1 error: %d\n", WSAGetLastError);
        break;
    }
    printf("size: %d\n", size);
    printf("r: %d\n", r);
    counter  ;
    printf("counter: %d\n", counter);
}
fclose(originalFile);

CodePudding user response：

Would make this a comment since it just riffs off what Alex F said, but not enough reputation. In any case, if you add rewind(f); after int sizeFile = ftell(f); in getSizeFile(FILE* file), that should solve the issue of not being able to read the file properly.