From: Ryan Sun > Stream and networking programming seems like a rock on the way to > ZCE for most people, so I'm learning some socket examples before I sit > in the room for exam. > Here is the script for server <snip> > server&client hangs after output and time out later. > > Can any1 point out whats the reason and the more correct way to get > socket client input in socket server? I have not done any socket programs in PHP, but I have in Assembler, C and Perl. First, I don't think feof() will do what you think it does. I wouldn't expect it to show up until after the other end has actually closed the connection. The other problem has to do with thinking an fread() will always give you everything you sent in an fwrite(). TCP is a stream protocol, there are no guarantees about delivering a complete message in one read, or that two writes won't be read together. It only guarantees that all octets will eventually be delivered in the same order they were sent, or you will get an error. The buffering is completely hidden and outside of your control. If you want writes to be atomic, you want UDP, but then you lose the guarantee of delivery. If you want to enforce a structure on the data in that stream, it is your application's responsibility to reconstruct that data at the receiver. One other detail that may or may not make a difference. TCP actually defines two independent pipes, one in each direction. Many Unix applications create two processes to service a socket, one to send, the other to receive. Only occasionally does a protocol require alternating messages similar to a conversation or ping-pong match. Bob McConnell -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
