C++ :: Sending Variable Amount Of Data Over Winsock?

Client:

Code: ....
string cmd = "dir c:filequeue > ";
string outputFilePath;
outputFilePath.append(getTempPath());
outputFilePath.append(" est.txt");
cmd.append(outputFilePath);
system(cmd.c_str()); // dir c:filequeue > %temp% est.txt
string content = get_file_contents(outputFilePath.c_str());

send(s, content.c_str(), content.length(), 0); I'm executing the "dir" command to get a listing of Folders/files of one Folder. Then I read the Output of the file and send it over winsock to the Server.

Now, the Problem is, I don't know how I can handle the recv properly, cause I have to set the buffer size without knowing, how much data is actually transfered. Sometimes maybe no files are in c:filequeue, sometimes a 100k.

So I tried to make recv as a Loop:

Server:

Code: ...

while (rc != SOCKET_ERROR) {
printf("
#");
gets(buf); //please no discussion about gets, I will Change this later ;)
if (strcmp(buf, "ls") == 0){
send(connectedSocket, "LIST", 4, 0);

[Code] .....

now it works, but as the recv blocks, it will never leave the Loop, even when the Transfer is finished.What should I do?

I believe I could make unblocking sockets, but that's a bit complicated. Isn't there an easier solution, with malloc'ing the buffer or a Signal when to leave the recv Loop?