Get the IP of a player, Minetest command.

get_player_ip.lua

minetest.register_chatcommand("ip", {
    params = "<name>",
    description = "Show the IP of a player",
    privs = {server = true},
    func = function(name, param)
		-- If no playername is specified you will get a help message
		if param == "" then
			minetest.chat_send_player(name, "Usage: /ip <playername>")
			return
		end
		-- If the player specified does not exist then you will get a message
		if minetest.get_player_by_name(param) == nil then
			minetest.chat_send_player(name, "The specified player was not found...")
			return
		end
		-- Gets the IP of the player and sends it to the player who used the command
		minetest.chat_send_player(name, "IP of ".. param .." is ".. minetest.get_player_ip(param))
    end,
})

--TO DO
--Search auth.txt for players with the same IP.