Add battery support for OpenBSD (#76)

README.md

@@ -141,11 +141,12 @@ return a table of values to be formatted by `format`.
 
 Provides state, charge, and remaining time for a requested battery.
 
-Supported platforms: GNU/Linux (require `sysfs`), FreeBSD (require `acpiconf`).
+Supported platforms: GNU/Linux (require `sysfs`), FreeBSD (require `acpiconf`), OpenBSD (no extra requirements).
 
 * `warg` (from now on will be called *argument*):
     * On GNU/Linux: battery ID, e.g. `"BAT0"`
     * On FreeBSD (optional): battery ID, e.g. `"batt"` or `"0"`
+    * On OpenBSD (optional): `bat` followed by battery index, e.g. `bat0` or `bat1` on systems with more than one battery
 * Returns an array (integer-indexed table) consisting of:
     * `$1`: State of requested battery
     * `$2`: Charge level in percent

helpers.lua

@@ -64,7 +64,8 @@ function helpers.wrequire(table, key)
 
     local ostable = {
         linux = { "linux", "all" },
-        freebsd = { "freebsd", "bsd", "all" }
+        freebsd = { "freebsd", "bsd", "all" },
+        openbsd = { "openbsd", "bsd", "all" }
     }
 
     local os = ostable[helpers.getos()]

widgets/bat_openbsd.lua

@@ -0,0 +1,72 @@
+-- {{{ Grab environment
+local setmetatable = setmetatable
+local tonumber = tonumber
+local string = { format = string.format, gmatch = string.gmatch }
+local io = { popen = io.popen }
+local math = { floor = math.floor }
+local helpers = require("vicious.helpers")
+local string = {
+    gmatch = string.gmatch,
+    match = string.match,
+    format = string.format
+}
+-- }}}
+local bat_openbsd = {}
+
+local function worker(format, warg)
+    local battery = warg or "bat0"
+    local filter = string.format("hw.sensors.acpi%s", battery)
+    local cmd = string.format("sysctl -a | grep '^%s'", filter)
+    local proc = io.popen(cmd)
+
+    local bat_info = {}
+    for line in proc:lines("*l") do
+        for key, value in string.gmatch(line, "(%S+)=(%S+)") do
+	    key = key:gsub(filter .. ".", "")
+	    bat_info[key] = value
+        end
+    end
+
+    -- current state
+    local states = {[0] = "↯", -- not charging
+                    [1] = "-", -- discharging
+                    [2] = "!", -- critical
+                    [3] = "+", -- charging
+                    [4] = "N/A", -- unknown status
+                    [255] = "N/A"} -- unimplemented by the driver
+    local state = states[tonumber(bat_info.raw0)]
+
+    -- battery capacity in percent
+    local percent = tonumber(bat_info.watthour3 / bat_info.watthour0 * 100)
+
+    local time
+    if tonumber(bat_info.power0) < 1 then
+        time = "∞"
+    else
+	local raw_time = bat_info.watthour3 / bat_info.power0
+	local hours = math.floor(raw_time)
+	local minutes = raw_time % 1
+	time = string.format("%d:%0.2d", hours, minutes)
+    end
+
+    -- calculate wear level from (last full / design) capacity
+    local wear = "N/A"
+    if bat_info.watthour0 and bat_info.watthour4 then
+        local l_full = tonumber(bat_info.watthour0)
+        local design = tonumber(bat_info.watthour4)
+        wear = math.floor(l_full / design * 100)
+    end
+
+    -- dis-/charging rate as presented by battery
+    local rate = bat_info.power0
+
+    -- returns
+    --  * state (high "↯", discharging "-", charging "+", N/A "⌁" }
+    --  * remaining_capacity (percent)
+    --  * remaining_time, by battery
+    --  * wear level (percent)
+    --  * present_rate (W)
+    return {state, percent, time, wear, rate}
+end
+
+return setmetatable(bat_openbsd, { __call = function(_, ...) return worker(...) end })