Added new wifi widget using iw (#20)

* added new wifi widget that uses iw

README

@@ -221,6 +221,13 @@ vicious.widgets.wifi
   - returns a table with string keys: {ssid}, {mode}, {chan}, {rate},
     {link}, {linp} (link quality in percent) and {sign} (signal level)
 
+vicious.widgets.wifiiw
+  - similar to vicious.widgets.wifi, but uses iw instead of iwconfig
+  - provides wireless information for a requested interface
+  - takes the network interface as an argument, i.e. "wlan0"
+  - returns a table with string keys: {ssid}, {mode}, {chan}, {rate},
+    {freq}, {linp} (link quality in percent), {txpw} (tx power) and {sign} (signal level)
+
 vicious.widgets.mbox
   - provides the subject of last e-mail in a mbox file
   - takes the full path to the mbox as an argument, or a table with

README.md

@@ -254,6 +254,15 @@ string.
   - returns a table with string keys: {ssid}, {mode}, {chan}, {rate},
     {link}, {linp} (link quality in percent) and {sign} (signal level)
 	
+**vicious.widgets.wifiiw**
+
+  - similar to vicious.widgets.wifi, but uses iw instead of iwconfig
+  - provides wireless information for a requested interface
+  - takes the network interface as an argument, i.e. "wlan0"
+  - returns a table with string keys: {ssid}, {mode}, {chan}, {rate},
+    {freq}, {linp} (link quality in percent), {txpw} (tx power) and {sign} (signal level)
+
+
 **vicious.widgets.mbox**
 
   - provides the subject of last e-mail in a mbox file

widgets/wifiiw.lua

@@ -0,0 +1,66 @@
+---------------------------------------------------
+-- Licensed under the GNU General Public License v2
+--  * (c) 2016, Marius M. <mellich@gmx.net>
+---------------------------------------------------
+
+-- {{{ Grab environment
+local tonumber = tonumber
+local setmetatable = setmetatable
+local helpers = require("vicious.helpers")
+local io = {
+    open  = io.open,
+    popen = io.popen
+}
+local string = {
+    find  = string.find,
+    match = string.match
+}
+-- }}}
+
+
+-- Wifiiw: provides wireless information for a requested interface using iw instead of deprecated iwconfig
+-- vicious.widgets.wifiiw
+local wifiiw = {}
+
+
+-- {{{ Wireless widget type
+local function worker(format, warg)
+    if not warg then return end
+
+    -- Default values
+    local winfo = {}
+
+    -- Get data from iw where available
+    local f = io.popen("export PATH=$PATH:/sbin/:/usr/sbin:/usr/local/sbin;" ..
+					"iw dev ".. helpers.shellquote(tostring(warg)) .. " link 2>&1;" ..
+					"iw dev ".. helpers.shellquote(tostring(warg)) .. " info 2>&1")
+    local iwresult = f:read("*all")
+    f:close()
+
+    -- iw wasn't found, isn't executable, or non-wireless interface
+    if iwresult == nil or string.find(iwresult, "No such device") then
+        return winfo
+    end
+	-- string match is simple in most cases, because iw uses a new line for every info
+    winfo["{ssid}"] =  -- SSID can have almost anything in it until new line
+      string.match(iwresult, "SSID: ([^\n]*)") or "N/A"
+    winfo["{mode}"] =  -- everything after 'type ' until new line
+      string.match(iwresult, "type ([^\n]*)") or "N/A"
+    winfo["{chan}"] =  -- Channels are plain digits
+      tonumber(string.match(iwresult, "channel ([%d]+)") or 0)
+    winfo["{rate}"] =  -- We don't want to display Mb/s
+      tonumber(string.match(iwresult, "tx bitrate: ([%d%.]*)") or 0)
+    winfo["{freq}"] =  -- Frequency are plain digits
+      tonumber(string.match(iwresult, "freq: ([%d]+)") or 0)
+    winfo["{sign}"] =  -- Signal level can be a negative value, don't display decibel notation
+      tonumber(string.match(iwresult, "signal: (%-[%d]+)") or 0)
+    winfo["{linp}"] =  -- Link Quality using the Windows definition (-50dBm->100%, -100dBm->0%)
+      (winfo["{sign}"] ~= 0 and 100 - ((winfo["{sign}"] * -2) - 100) or 0)
+    winfo["{txpw}"] =  -- TX Power can be a negative value, don't display decibel notation
+      tonumber(string.match(iwresult, "txpower ([%-]?[%d]+)") or 0)
+
+    return winfo
+end
+-- }}}
+
+return setmetatable(wifiiw, { __call = function(_, ...) return worker(...) end })