subscribe example?

[paul-shannon]

?subscribe does not show an example (as far as I could see).
experimentation failed:

context <- init.context()
socket <- init.socket(context, "ZMQ_REQ")
connect.socket(socket, "tcp://localhost:5432")
subscribe(socket, "") # following node.js example
--> Invalid argument

I'd be very grateful for a small working example!

Thanks,

• Paul

[armstrtw]

Hmm, I haven't tried it with an empty string.

Have a look at this pdf for now starting on page 13:
http://www.rinfinance.com/agenda/2013/workshop/Armstrong+Lewis.pdf

[paul-shannon]

Hi Whit,

The pdf is very helpful. It turns out that the empty string DOES work - and appears to be interpreted as “subscribe to all messages”. I had failed to specify “ZMQ_SUB” in my init.socket call.

For what it’s worth, my learning exercise is a companion piece to the zmq chapter in

Node.js the Right Way: Practical, Server-Side JavaScript That Scales
by Jim R. Wilson

Your library works great now that I am using it properly. Many thanks.

My working version (on the off chance you’d find it interesting) subscribing to the messages published in Wilson’s zmq-watcher-pub.js:

library(rzmq)
library(jsonlite)
context = init.context()
socket = init.socket(context,"ZMQ_SUB")
connect.socket(socket,"tcp://localhost:5432”)
subscribe(socket, “”) # all messages

i <- 0
while (i < 5) {
res <- receive.socket(socket, unserialize=FALSE)
x <- fromJSON(rawToChar(res))
print(x)
i <- i + 1
}

Many thanks!

• Paul

On Jan 23, 2016, at 1:54 PM, Whit Armstrong notifications@github.com wrote:

Hmm, I haven't tried it with an empty string.

Have a look at this pdf for now starting on page 13:
http://www.rinfinance.com/agenda/2013/workshop/Armstrong+Lewis.pdf

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