examples: add a Lua example for getting Wi-Fi access points

examples/lua/lgi/Makefile.am

@@ -1,4 +1,5 @@
 EXTRA_DIST = \
 	add-connection.lua \
 	list-connections.lua \
-	list-devices.lua
+	list-devices.lua \
+	show-wifi-networks.lua

examples/lua/lgi/show-wifi-networks.lua

@@ -0,0 +1,79 @@
+#!/usr/bin/env lua
+-- -*- Mode: Lua; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+-- vim: ft=lua ts=2 sts=2 sw=2 et ai
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License along
+-- with this program; if not, write to the Free Software Foundation, Inc.,
+-- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+--
+-- Copyright 2015 Red Hat, Inc.
+--
+--
+-- This example lists Wi-Fi access points NetworkManager scanned on Wi-Fi devices.
+-- The example uses libnm library using GObject introspection via Lua lgi module.
+-- Most distribution ship the module as lua-lgi package.
+-- libnm guide:   https://developer.gnome.org/libnm/1.0/
+-- Lua-lgi guide: https://github.com/pavouk/lgi/blob/master/docs/guide.md
+--
+
+local lgi = require 'lgi'
+local NM = lgi.NM
+
+function ssid_to_utf8(ap)
+  local ssid = ap:get_ssid()
+  if not ssid then return "" end
+  return NM.utils_ssid_to_utf8(ssid:get_data())
+end
+
+function print_device_info(device)
+  local active_ap = device:get_active_access_point()
+  if active_ap then ssid = ssid_to_utf8(active_ap) end
+  local info = string.format("Device: %s | Driver: %s | Active AP: %s",
+                             device:get_iface(), device:get_driver(), ssid)
+  print(info)
+  print(string.rep("=", info:len()))
+end
+
+function print_ap_info(ap)
+  local strength = ap:get_strength()
+  local frequency = ap:get_frequency()
+  print("SSID:      ", ssid_to_utf8(ap))
+  print("BSSID:     ", ap:get_bssid())
+  print("Frequency: ", frequency)
+  print("Channel:   ", NM.utils_wifi_freq_to_channel(frequency))
+  print(string.format("Strength:  %s %s%%", NM.utils_wifi_strength_bars(strength), strength))
+  print("")
+end
+
+
+---------------------------
+-- Main code starts here --
+---------------------------
+-- Call setlocale() else NM.utils_wifi_strength_bars() will think the locale
+-- is ASCII-only, and return the fallback characters rather than the unicode bars
+os.setlocale('')
+
+-- get all devices
+client = NM.Client.new()
+devs = client:get_devices()
+
+-- print APs for all Wi-Fi devices
+for _, dev in ipairs(devs) do
+  if dev:get_device_type() == "WIFI" then
+    print_device_info(dev)
+    for _, ap in ipairs(dev:get_access_points()) do
+      print_ap_info(ap)
+    end
+  end
+end
+