Talk to custom protocols using asynchronous UDP sockets.
For TCP sockets see hs.socket
.
You can do a lot of neat trivial and non-trivial things with these. A simple ping ponger:
function ping(data, addr)
print(data)
addr = hs.socket.parseAddress(addr)
hs.timer.doAfter(1, function()
client:send("ping", addr.host, addr.port)
end)
end
function pong(data, addr)
print(data)
addr = hs.socket.parseAddress(addr)
hs.timer.doAfter(1, function()
server:send("pong", addr.host, addr.port)
end)
end
server = hs.socket.udp.server(9001, pong):receive()
client = hs.socket.udp.new(ping):send("ping", "localhost", 9001):receive()
Resulting in the following endless exchange:
20:26:56 LuaSkin: (secondary thread): Data written to UDP socket
LuaSkin: (secondary thread): Data read from UDP socket
ping
20:26:57 LuaSkin: (secondary thread): Data written to UDP socket
LuaSkin: (secondary thread): Data read from UDP socket
pong
20:26:58 LuaSkin: (secondary thread): Data written to UDP socket
LuaSkin: (secondary thread): Data read from UDP socket
ping
20:26:59 LuaSkin: (secondary thread): Data written to UDP socket
LuaSkin: (secondary thread): Data read from UDP socket
pong
...
You can do some silly things with a callback factory and enabling broadcasting:
local function callbackMaker(name)
local fun = function(data, addr)
addr = hs.socket.parseAddress(addr)
print(name.." received data:\n"..data.."\nfrom host: "..addr.host.." port: "..addr.port)
end
return fun
end
local listeners = {}
local port = 9001
for i=1,3 do
table.insert(listeners, hs.socket.udp.new(callbackMaker("listener "..i)):reusePort():listen(port):receive())
end
broadcaster = hs.socket.udp.new():broadcast()
broadcaster:send("hello!", "255.255.255.255", port)
Since neither IPv4 nor IPv6 have been disabled, the broadcast is received on both protocols ('dual-stack' IPv6 addresses shown):
listener 2 received data:
hello!
from host: ::ffff:192.168.0.3 port: 53057
listener 1 received data:
hello!
from host: ::ffff:192.168.0.3 port: 53057
listener 3 received data:
hello!
from host: ::ffff:192.168.0.3 port: 53057
listener 1 received data:
hello!
from host: 192.168.0.3 port: 53057
listener 3 received data:
hello!
from host: 192.168.0.3 port: 53057
listener 2 received data:
hello!
from host: 192.168.0.3 port: 53057
Signature | hs.socket.udp.timeout |
---|---|
Type | Variable |
Description |
Timeout for the socket operations, in seconds. |
Notes |
|
Source | extensions/socket/socket.lua line 173 |
Signature | hs.socket.udp.parseAddress(sockaddr) -> table or nil |
---|---|
Type | Function |
Description |
Alias for |
Parameters | |
Returns | |
Source | extensions/socket/socket.lua line 184 |
Signature | hs.socket.udp.new([fn]) -> hs.socket.udp object |
---|---|
Type | Constructor |
Description |
Creates an unconnected asynchronous UDP socket object. |
Parameters |
|
Returns |
|
Source | extensions/socket/libsocket_udp.m line 111 |
Signature | hs.socket.udp.server(port[, fn]) -> hs.socket.udp object |
---|---|
Type | Constructor |
Description |
Creates a UDP socket, and binds it to a port for listening. |
Parameters |
|
Returns |
|
Source | extensions/socket/socket.lua line 208 |
Signature | hs.socket.udp:broadcast([flag]) -> self or nil |
---|---|
Type | Method |
Description |
Enables broadcasting on the underlying socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 418 |
Signature | hs.socket.udp:close() -> self |
---|---|
Type | Method |
Description |
Immediately closes the socket, freeing it for reuse. Any pending send operations are discarded. |
Parameters |
|
Returns |
|
Source | extensions/socket/libsocket_udp.m line 222 |
Signature | hs.socket.udp:closed() -> bool |
---|---|
Type | Method |
Description |
Returns the closed status of the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 675 |
Signature | hs.socket.udp:connect(host, port[, fn]) -> self or nil |
---|---|
Type | Method |
Description |
Connects an unconnected socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 145 |
Signature | hs.socket.udp:connected() -> bool |
---|---|
Type | Method |
Description |
Returns the connection status of the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 652 |
Signature | hs.socket.udp:enableIPv(version[, flag]) -> self or nil |
---|---|
Type | Method |
Description |
Enables or disables IPv4 or IPv6 on the underlying socket. By default, both are enabled. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 486 |
Signature | hs.socket.udp:info() -> table |
---|---|
Type | Method |
Description |
Returns information about the socket. |
Parameters |
|
Returns |
|
Source | extensions/socket/libsocket_udp.m line 699 |
Signature | hs.socket.udp:listen(port) -> self or nil |
---|---|
Type | Method |
Description |
Binds an unconnected socket to a port for listening. |
Parameters |
|
Returns |
|
Source | extensions/socket/libsocket_udp.m line 192 |
Signature | hs.socket.udp:pause() -> self |
---|---|
Type | Method |
Description |
Suspends reading of packets from the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 243 |
Signature | hs.socket.udp:preferIPv([version]) -> self |
---|---|
Type | Method |
Description |
Sets the preferred IP version: IPv4, IPv6, or neutral (first to resolve). |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 523 |
Signature | hs.socket.udp:read(delimiter[, tag]) -> self |
---|---|
Type | Method |
Description |
Alias for |
Parameters | |
Returns | |
Source | extensions/socket/socket.lua line 237 |
Signature | hs.socket.udp:readOne(delimiter[, tag]) -> self |
---|---|
Type | Method |
Description |
Alias for |
Parameters | |
Returns | |
Source | extensions/socket/socket.lua line 243 |
Signature | hs.socket.udp:receive([fn]) -> self or nil |
---|---|
Type | Method |
Description |
Reads packets from the socket as they arrive. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 295 |
Signature | hs.socket.udp:receiveOne([fn]) -> self or nil |
---|---|
Type | Method |
Description |
Reads a single packet from the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 321 |
Signature | hs.socket.udp:reusePort([flag]) -> self or nil |
---|---|
Type | Method |
Description |
Enables port reuse on the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 452 |
Signature | hs.socket.udp:send(message[, host, port][, tag, fn]) -> self |
---|---|
Type | Method |
Description |
Sends a packet to the destination address. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 347 |
Signature | hs.socket.udp:setBufferSize(size[, version]) -> self |
---|---|
Type | Method |
Description |
Sets the maximum size of the buffer that will be allocated for receive operations. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 555 |
Signature | hs.socket.udp:setCallback([fn]) -> self |
---|---|
Type | Method |
Description |
Sets the read callback for the socket. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 597 |
Signature | hs.socket.udp:setTimeout(timeout) -> self |
---|---|
Type | Method |
Description |
Sets the timeout for the socket operations. |
Parameters |
|
Returns |
|
Notes |
|
Source | extensions/socket/libsocket_udp.m line 628 |
Signature | hs.socket.udp:write(message[, tag]) -> self |
---|---|
Type | Method |
Description |
Alias for |
Parameters | |
Returns | |
Source | extensions/socket/socket.lua line 249 |
© 2014–2017 Hammerspoon contributors
Licensed under the MIT License.
https://www.hammerspoon.org/docs/hs.socket.udp.html