ludic/docs/language/udp/udp-open_local.md

id	name	category	kind	tokens	sig	tip	order	ns	member
udp-open_local	Udp.open_local	udp	namespace-method	Udp.open_local	Udp.open_local(port) -> int	Open a socket only this machine can reach.	0	Udp	open_local

Opens a non-blocking IPv4 socket like Udp.open, but bound to 127.0.0.1 alone: programs on the same machine reach it, and nothing on the network can. Use it for a port only local tools should talk to, such as a development link. Returns the handle, or 0 when it could not.

program Demo {
  entry {
    let s = Udp.open_local(port: 0)
    print(s > 0)
  }
}