From b5c16f0472b10f63ce1865433acefb3f36174395 Mon Sep 17 00:00:00 2001
From: Michael Santos <michael.santos@gmail.com>
Date: Sun, 16 Nov 2014 15:38:09 -0500
Subject: [PATCH] Fix the echo example

The behaviour of gen_tcp:listen/2 seems to have changed at some point:
if a non-zero port is passed in, the inet driver attempts to bind this
port, even if an 'fd' parameter exists in the options.

Setting the port to 0 seems to force inet to use the fd option.
---
 examples/echo.erl | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/examples/echo.erl b/examples/echo.erl
index 075dc9b..2c26449 100644
--- a/examples/echo.erl
+++ b/examples/echo.erl
@@ -47,13 +47,13 @@ start(Port, Options) ->
     Family = proplists:get_value(family, Options, inet),
     {ok, Fd} = procket:open(Port, Options),
     io:format("Listening on: ~p/~p~n", [Port, Protocol]),
-    listen(Protocol, Family, Fd, Port).
+    listen(Protocol, Family, Fd).
 
-listen(tcp, Family, Fd, Port) ->
-    {ok, S} = gen_tcp:listen(Port, [binary, Family, {fd, Fd}]),
+listen(tcp, Family, Fd) ->
+    {ok, S} = gen_tcp:listen(0, [binary, Family, {fd, Fd}]),
     accept(S);
-listen(udp, Family, Fd, Port) ->
-    {ok, S} = gen_udp:open(Port, [binary, Family, {fd, Fd}]),
+listen(udp, Family, Fd) ->
+    {ok, S} = gen_udp:open(0, [binary, Family, {fd, Fd}]),
     recv(S).
 
 accept(LS) ->