recv() problem?

Hi,
I'm kind of new for networking programming and need to write some
basic socket connection (in C) using 2 linux machines that do the
following:
The client sends request (query) to the server, then the server needs
to send the query results to the client. So I established the
connection, and the client seems to get the query correctly and send
the results back to the client. The only problem is that the client is
either getting part of the data- when I'm using:
/*********************************************
RECEIVES THE OUTPUT FROM THE SERVER
**********************************************/
strcpy(buf, "");
if ((numbytes=recv(sockfd, buf, MAX-1, 0)) == -1) {
error("recv");
exit(1);
}
buf[numbytes] = '\0';
printf("%s",buf);

or when I'm trying to use a while loop it got stuck forever...:

/*********************************************
RECEIVES THE OUTPUT FROM THE SERVER - loop
**********************************************/
strcpy(buf, "");
while(recv(sockfd, buf, MAX-1, 0) >0) {
printf("%s",buf);
}


as for the server, I'm using:
/**********************************
SENDS THE OUPUT
***********************************/
if (send(new_fd, rdata1, MAX, 0) == -1){
//error
}
close(new_fd);
exit(0);

what is wrong with this? How can I terminate the recv() in such a way
that it should stop after getting all the data back? Any help will be
appreciated.

Thanks.