contrib: import nvidia SMI widget type

Right now nvsmi is just interested in temperature information. My
streaming server GPU 'fell of the bus' last night while decoding
video, I suspect overheating.

contrib/README

@@ -68,6 +68,11 @@ vicious.contrib.openweather
   - returns a table with string keys: {city}, {wind deg}, {wind aim},
     {wind kmh}, {wind mps}, {sky}, {weather}, {temp c}, {humid}, {press}
 
+vicious.contrib.nvsmi
+  - provides (very basic) information about Nvidia GPU status from SMI
+  - takes optional card ID as an argument, i.e. "1", or defaults to ID 0
+  - returns 1st value as temperature of requested graphics device
+
 vicious.contrib.ossvol
   -
 

contrib/nvsmi.lua

@@ -0,0 +1,42 @@
+---------------------------------------------------
+-- Licensed under the GNU General Public License v2
+--  * (c) 2014, Adrian C. <anrxc@sysphere.org>
+---------------------------------------------------
+
+-- {{{ Grab environment
+local tonumber = tonumber
+local io = { popen = io.popen }
+local setmetatable = setmetatable
+local string = { match = string.match }
+-- }}}
+
+
+-- nvsmi: provides GPU information from nvidia SMI
+-- vicious.contrib.nvsmi
+local nvsmi = {}
+
+
+-- {{{ GPU Information widget type
+local function worker(format, warg)
+    -- Fallback to querying first device
+    if not warg then warg = "0" end
+
+    -- Get data from smi
+    -- * Todo: support more; MEMORY,UTILIZATION,ECC,POWER,CLOCK,COMPUTE,PIDS,PERFORMANCE
+    local f = io.popen("nvidia-smi -q -d TEMPERATURE -i " .. warg)
+    local smi = f:read("*all")
+    f:close()
+
+    -- Not installed
+    if smi == nil then return {0} end
+
+    -- Get temperature information
+    local _thermal = string.match(smi, "Gpu[%s]+:[%s]([%d]+)[%s]C")
+    -- Handle devices without data
+    if _thermal == nil then return {0} end
+
+    return {tonumber(_thermal)}
+end
+-- }}}
+
+return setmetatable(nvsmi, { __call = function(_, ...) return worker(...) end })