Re: Help on sending a UDP Packet

[Gary Highberger]

Hello David and all,

I have a few (noob) questions about the UDP example Smalltalk program. More
questions likely to follow as I come up to speed. Your patience is much
appreciated David and everybody.

QUESTIONS:
•  Is "_" the preferred assignment operator? I've been seeing ":=" too. I
don't have a back arrow on my keyboard. I guess the PARC people used "_".

•  Does statement 1)
assign the destination IP address? Note that for my application, the source
and destination addresses will be different.

•  Does statement 3)
populate the (UDP) datagram socket with the message, port, and address? Why
a "#" symbol prefixing the message string, 'hello world'?

•  Does statement 4)
create a listening socket?

•  Does statement 5)
trigger the send?

•  Does statement 6)
block until the UDP response?

+---------------------------------------------------------+

UDP Smalltalk (example) program:

1) h _ Sockets.SocketAddress createLoopbackHost.

2) s _ Sockets.DatagramSocket new.

3) d _ Sockets.Datagram data:#'hello world' address:h port:13.

4) answer _ Sockets.Datagram new.

5) s nextPut:d.

6) s receive:answer.

7) (answer data) asString printNl.

8) s close.

Gary Highberger


On Sun, Jan 10, 2021, 8:48 AM Gary Highberger <gary.highberger@gmail.com>
wrote:

> Good morning David,
>
> I'm not familiar with 'daytime' but will come up to speed on it and get it
> and your use cases running and report my findings for everybody to see.
>
> Hopefully netTest.c explains what I'm trying to do with Smalltalk. It's
> very short and simple.
>
> https://www.dropbox.com/s/xc23wj6r5aqh153/netTest.c?dl=0
>
> I used my cell phone as the destination, my home WiFi as the network, and
> tcpdump to see the packet.
>
> Thank you David for the Smalltalk code fragments and introducing me to
> inetd and 'daytime'.
>
> Gary Highberger
>
>
>