Sending AND Receiving on the Same Port

HalNineThousand has asked for the wisdom of the Perl Monks concerning the following question:

I've been searching and I've found a LOT of tutorials on creating sockets in Perl. In a few cases there's even chat applications.

What I haven't found is anything on how to send AND receive on the same port.

I want to be able to send out a broadcast message (which I know is UDP), then listen for a response on the same port. This is a simple app to find a system when you can't be sure where it is on the LAN (in case I can't get an assigned IP address for the system).

Are there any tutorials or is there any information using a socket on one port for sending AND receiving? (Or a way to make one socket to listen and one to send?)

Comment on Sending AND Receiving on the Same Port

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Re: Sending AND Receiving on the Same Port by ikegami (Patriarch) on Feb 23, 2011 at 22:09 UTC
What I haven't found is anything on how to send AND receive on the same port. It's impossible for a socket to do otherwise. Maybe the bit you are missing is that you need to use the same socket for sending and receiving? Unlike (most?) pipes, sockets are bidirectional.	[reply]
Re^2: Sending AND Receiving on the Same Port by HalNineThousand (Beadle) on Feb 24, 2011 at 01:29 UTC
Okay, I get that. I've been playing around with it. Now there's only one other issue: My first message is a broadcast message, so I have the socket set to broadcast. It appears the issue is that I can't listen on the same socket I broadcast on. Am I right on this? If so, how do I sent out a broadcast message, then listen for a reply on the same port? Since it seems if I broadcast, I can't also listen, in the time it takes to make a new socket, won't data be incoming and lost?	[reply]
Re^3: Sending AND Receiving on the Same Port by ikegami (Patriarch) on Feb 24, 2011 at 02:08 UTC
It appears the issue is that I can't listen on the same socket I broadcast on. Am I right on this? That makes no sense. Each message is completely independent in UDP. You can send to anyone and receive from anyone with a single socket. in the time it takes to make a new socket, won't data be incoming and lost? Why would someone be sending to a socket you haven't created yet?	[reply]
Re^4: Sending AND Receiving on the Same Port by HalNineThousand (Beadle) on Feb 24, 2011 at 02:53 UTC
Re^5: Sending AND Receiving on the Same Port (udp broadcast example) by ikegami (Patriarch) on Feb 24, 2011 at 05:24 UTC
Re^5: Sending AND Receiving on the Same Port by ikegami (Patriarch) on Feb 24, 2011 at 04:53 UTC
Re^4: Sending AND Receiving on the Same Port by HalNineThousand (Beadle) on Feb 24, 2011 at 17:35 UTC