I try to send a .jpeg file from client to server. Everytime I read a byte in my client I immediatley send it to my server and write it to the file. The file creation goes successfully but when I open the new image it doesn't view it. How can I send a file successfully?

server:

char buf[BUFSIZ]; // Array where the read objects are stored
FILE* copyFile; // Write to this
fopen_s(&copyFile, "C:\\Users\\name\\Documents\\img3.jpeg", "wb");

while (1)
{
    recv(s, buf, BUFSIZ, 0);
    fwrite(buf, 1, BUFSIZ, copyFile);
}
fclose(copyFile);

client:

char buf[BUFSIZ]; // Array where the read objects are stored
size_t size = BUFSIZ;
FILE* originalFile; // Read from this
fopen_s(&originalFile, "C:\\Users\\name\\Documents\\img.jpeg", "rb");

while (size == BUFSIZ)
{
    size = fread(buf, 1, BUFSIZ, originalFile);
    send(ClientSocket, buf, 1, 0);
}
fclose(originalFile);

CodePudding user response：

You are ignoring the return values of both fread()/fwrite() and send()/recv(). They tell you how many bytes were actually read/written and sent/received, respectively. Never ignore the return values of system calls.

Try this instead:

server:

FILE* copyFile; // Write to this
if (fopen_s(&copyFile, "C:\\Users\\name\\Documents\\img3.jpeg", "wb") == 0)
{
    char buf[BUFSIZ]; // Array where the read objects are stored
    int numRecvd;
    while ((numRecvd = recv(s, buf, sizeof(buf), 0)) > 0)
    {
        if (fwrite(buf, numRecvd, 1, copyFile) != 1) break;
    }
    fclose(copyFile);
}

client:

FILE* originalFile; // Read from this
if (fopen_s(&originalFile, "C:\\Users\\name\\Documents\\img.jpeg", "rb") == 0)
{
    char buf[BUFSIZ]; // Array where the read objects are stored
    size_t size;
    while ((size = fread(buf, 1, sizeof(buf), originalFile)) > 0)
    {
        char *ptr = buf;
        do {
            int numSent = send(ClientSocket, ptr, size, 0);
            if (numSent < 0) break;
            ptr  = numSent;
            size -= numSent;
        }
        while (size > 0);
        if (size != 0) break;
    }
    fclose(originalFile);
}