World: r3wp

So how do I "query" a port?

my R3 need with DNS is to be able to tell if a domain is there or 
was it mistyped, to prevent calamity

in the awake handler, there is a 'lookup event

inside this event, use query port

I'm guessing here of course :)

rebol []
make-scheme [
	name: 'dns2
	title: "DNS Protocol"
	spec: make system/standard/port-spec-net [port-id: 80]


	awake: funct [event ] [
		print ["=== Client event:" event/type]
		client: event/port
		switch event/type [
			lookup [
				; print "DNS lookup"
				probe query client
				return true
			]
			connect []
		]
	]
	actor: [
		open: func [
			port [port!]
			/local conn
		] [
			if port/state [return port]
			if none? port/spec/host [http-error "Missing host address"]
			; set the port state
			port/state: context [
				state:
				connection:
				error: none
				awake: none ;:port/awake
				close?: no
			]
			; create the tcp port and set it to port/state/connection
			port/state/connection: conn: make port! [
				scheme: 'tcp
				host: port/spec/host
				port-id: port/spec/port-id
				ref: rejoin [tcp:// host ":" port-id]
			]
			conn/awake: :awake
			open conn
			print "port opened ..."
			; return the newly created and open port
			wait conn
			conn
		]
	]
]

open dns2://www.rebol.com

open? will read work too? Feels weird ...

what do you mean?

Hmm.. why can't I overwrite the existing scheme?

I mean - I was used to get data by using 'read, not 'open .... Open 
just always opened the port, nothing more ... now try following with 
your solution:

print read dns://www.rebol.com

Don't understand.

I only wrote an open actor for my dns scheme

Should be enough

make-scheme [
	title: "Dns"
	name: 'dns2
	actor: [
		read: func [port [port!] /con][
			con: open [scheme: 'tcp host: port/spec/host]
			con/awake: func [event][true]
			wait [con 5]  ;*** timeout 5 secs
			attempt [get in query con 'remote-ip]
		]
	]
]
>>read dns2://www.rebol.net
216.240.11.203

Thanks Steeve!

not that i don't need to close the tcp port because it is not (really) 
opened yet

not=notice

I didn't open the port either

Normally one would open the port in the lookup event

yep

Andreas likes to use funct so no need to declare the locals

Now how to do a reverse dns lookup??

i don't have any idea how to do that

>>read reverse dns2://216.240.11.203
www.rebol.net

oops ... someone made this group web public!

ahah

we can change it back ...

the above was a joke!  please ignore

reverse lookups http://cr.yp.to/djbdns/intro-dns.html

IIRC we need UDP to do a DNS request.

So that we can't currently

Yeah .. just did a packet trace and it's all UDP

R3 does not contain UDP in networking device low level code?

not yet

Steeve, what's the algorithm for reading data from a port when you 
don't know how much data is coming down?

Does each arrival of data trigger a 'read event?

and does it append to port/data ?

some internals on how low level networking code works - http://www.rebol.net/wiki/TCP_Port_Details

yep graham

# Setup the IO-request data and length fields. Data is the buffer 
tail position. Length is the buffer space available from above. Clear 
the actual field.

so it does an append

but don't forget to execute a [read port] each time you received 
a packet , to be able to receive the futher one.

so you need to do a read port inside the read event?

yep

all this word overloading drives me crazy!

packet are append to port/data but the index is not moved

eh?

so how to read until there is no more data ?

no "eh?" me !!!
:-)

so the index is used by ??

there is no way to know how much packets can be received.
Your protocol has to send this info, if not you're tricked