Closed bonsairobo closed 3 months ago
Makes sense as well, I can add a wrapper for that. Thanks!
Cool, so I've added this. Currently just on master... it's going to need a major version bump since I had to update the return signature of the top-level methods to support accessing the OS-assigned port. For the "low-level" stuff, it's accessible at glisten/transport.{port}
and it uses the ListenSocket
. It probably works with both, but that's annoying to do with the Gleam type system.
I suspect it will be okay in practice to just look it up once the listen socket is obtained. If you have a use-case in mind that needs it otherwise, I can work around it. Will probably just need a separate function.
If you want, you can clone the repo and try it out as a path dependency. If you can, would be helpful to see if I did anything wrong 😅 if not, no worries!
Thanks!
It probably works with both, but that's annoying to do with the Gleam type system.
Understandable, I can't think of a use case for getting the bound port from an accept
call. I'm curious what you mean by "annoying" though.
Also OOC, what does the unknown
mean here?
pub fn port(socket: ListenSocket) -> Result(Int, unknown)
If you want, you can clone the repo and try it out as a path dependency
I just made a small change to the "low_level" example to see it working:
diff --git a/examples/low_level/src/low_level.gleam b/examples/low_level/src/low_level.gleam
index 5a087ab..20c2b81 100644
--- a/examples/low_level/src/low_level.gleam
+++ b/examples/low_level/src/low_level.gleam
@@ -1,13 +1,17 @@
+import gleam/int
import gleam/io
import gleam/result
import glisten/socket/options.{ActiveMode, Passive}
import glisten/tcp
+import glisten/transport
import logging
pub fn main() {
logging.configure()
- use listener <- result.then(tcp.listen(8000, [ActiveMode(Passive)]))
+ use listener <- result.then(tcp.listen(0, [ActiveMode(Passive)]))
+ use port <- result.then(transport.port(listener))
+ io.println("port = " <> int.to_string(port))
use socket <- result.then(tcp.accept(listener))
use msg <- result.then(tcp.receive(socket, 0))
io.debug(#("got a msg", msg))
Oh also the "echo_server" example is already doing this, but via the get_port
function.
For example, I would like to be able to get the port number of a socket like so:
Notice that port 0 is used so the OS will allocate a port for us. Without the
inet:port
function, there is no way to know what the actual port number is.I did something very simple here to test it out:
But I'm completely new to gleam, and I'm not sure how to make this work for both
ListenSocket
andSocket
types. I don't know any Erlang, so I'm not sure how those opaque types are related to the Erlanggen_tcp
code.I'm also not sure if
SocketReason
is the proper error type for this external function.