gistfile1.rb

require 'socket'

# Addrinfo#connect_internal
puts "(1) Addrinfo#connect (connect_internal)"
begin
  raise
rescue
  p Addrinfo.tcp('www.ruby-lang.org', 80).connect
end

# Addrinfo.bind
puts "\n(2) Addrinfo#bind"
begin
  ai = Addrinfo.tcp(nil, 11229)
  raise
rescue
  begin
    p ai.bind
  end
end

# Addrinfo.listen
puts "\n(3) Addrinfo#listen"
begin
  ai = Addrinfo.tcp(nil, 11228)
  raise
rescue
  begin
    p ai.listen
  end
end

# Socket.ip_sockets_port0
puts "\n(4) Socket.tcp_server_sockets (ip_sockets_port0)"
begin
  raise
rescue
  begin
    Socket.tcp_server_sockets(0)
  rescue IOError
    $stderr.puts "#{$!.class}: #{$!}", $!.backtrace
  end
end