[hwmontemp_linux] Deprecate io.popen

Note that all failures now return an empty table instead of { N/A },
since N/A indicates missing information from a successful attempt.

Changes.md

@@ -18,7 +18,7 @@ Added:
 Fixed:
 
 - Deprecate the use of `io.popen` in following widgets:
-    * wifi_linux, wifiiw_linux
+    * wifi_linux, wifiiw_linux, hwmontemp_linux
     * bat_freebsd, mem_freebsd, net_freebsd
     * volume, gmail, mdir, mpd
 - [mpd] Lua 5.3 compatibility (for real this time); also correct a typo

widgets/hwmontemp_linux.lua

@@ -4,57 +4,37 @@
 ----------------------------------------------------------------
 
 -- environment
-local io = { popen = io.popen, open = io.open }
-local assert = assert
-local setmetatable = setmetatable
+local type = type
+local tonumber = tonumber
+local io = { open = io.open }
 
--- sysfs prefix for hwmon devices
-local sys_hwmon = "/sys/class/hwmon/"
--- cache table for hwmon device names
-local paths = {}
-
--- transparently caching hwmon device name lookup
-function name_to_path(name)
-    if paths[name] then return paths[name] end
-
-    for sensor in io.popen("ls -1 " .. sys_hwmon):lines() do
-        local path = sys_hwmon .. sensor
-        local f = assert(io.open(path .. "/name", "r"))
-        local sname = f:read("*line")
-        f:close()
-        if sname == name then
-            paths[name] = path
-            return path
-        end
-    end
-
-    return nil
-end
+local helpers = require"vicious.helpers"
+local spawn = require"vicious.spawn"
 
 -- hwmontemp: provides name-indexed temps from /sys/class/hwmon
 -- vicious.widgets.hwmontemp
-local hwmontemp_linux = {}
-
-function worker(format, warg)
-    assert(type(warg) == "table", "invalid hwmontemp argument: must be a table")
-    name = warg[1]
-
-    if not warg[2] then
-        input = 1
+return helpers.setasyncall{
+    async = function (format, warg, callback)
+        if type(warg) ~= "table" or type(warg[1]) ~= "string" then
+            return callback{}
+        end
+        local input = warg[2]
+        if type(input) == "number" then
+            input = ("temp%d_input"):format(input)
         else
-        input = warg[2]
+            input = "temp1_input"
         end
 
-    local sensor = name_to_path(name)
-    if not sensor then return { "N/A" } end
-
-    local f = assert(io.open(("%s/temp%d_input"):format(sensor, input), "r"))
-    local temp = f:read("*line")
+        spawn.easy_async_with_shell(
+            "grep " .. warg[1] .. " -wl /sys/class/hwmon/*/name",
+            function (stdout, stderr, exitreason, exitcode)
+                if exitreason == "exit" and exitcode == 0 then
+                    local f = io.open(stdout:gsub("name%s+", input), "r")
+                    callback{ tonumber(f:read"*line") / 1000 }
                     f:close()
-
-    return { temp / 1000 }
+                else
+                    callback{}
                 end
-
-return setmetatable(hwmontemp_linux, { __call = function(_, ...) return worker(...) end })
-
+            end)
+    end }
 -- vim: ts=4:sw=4:expandtab