Avoiding program blocking while recv()

I need to send many chunks of a file through a socket ... while looping, the client need to check for incoming messages from the server.

ex:

Code:

---

while(1)
{
//check for incoming message from server
if (message) then recv();
else then continue sending;
}

---

if I use recv() for checking for incoming message, the program is blocked.

Is using poll() a good way to make it work ?

Thanks

Finally i'm tryin to use select()

But select always return -1 .... any idea ?

client side:
FD_ZERO(&readset);
FD_SET(mySocket, &readSet);
timeVal.tv_sec = 1;
timeVal.tv_usec = 0;

int result = select(mySocket + 1, &readSet, NULL, NULL, &timeVal);

server side:
messageSize = strlen(trame);
messageSize = htonl(messageSize);
(nBytes = send(clientSocket, (char*)&messageSize, sizeof(messageSize), 0);

> But select always return -1 .... any idea ?
Maybe look at the value stored in errno, and perhaps use perror() or strerror() to get a text description of the error.

Did you do this, and get a back socket?
if ( fd = socket() == 0 )