Load: new load average monitor

Closes #208

1 files changed, 45 insertions, 0 deletions

diff --git a/src/Xmobar/Plugins/Monitors/Load.hs b/src/Xmobar/Plugins/Monitors/Load.hs
new file mode 100644
index 0000000..238d374
--- /dev/null
+++ b/src/Xmobar/Plugins/Monitors/Load.hs
@@ -0,0 +1,45 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Plugins.Monitors.Load
+-- Copyright   :  Finn Lawler
+-- License     :  BSD-style (see LICENSE)
+--
+-- Author      :  Finn Lawler <flawler@cs.tcd.ie>
+-- Maintainer  :  jao <mail@jao.io>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A load average monitor for Xmobar.  Adapted from
+-- Xmobar.Plugins.Monitors.Thermal by Juraj Hercek.
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.Plugins.Monitors.Load (loadConfig, runLoad) where
+
+import Xmobar.Plugins.Monitors.Common
+import qualified Data.ByteString.Lazy.Char8 as B
+import System.Posix.Files (fileExist)
+
+-- | Default configuration.
+loadConfig :: IO MConfig
+loadConfig = mkMConfig
+       "Load: <load1>" -- template
+       ["load1", "load5", "load15"]       -- available replacements
+
+-- | Parses the contents of a loadavg proc file, returning
+-- the list of load averages
+parseLoadAvgs :: B.ByteString -> [Float]
+parseLoadAvgs =
+  map ((read :: String -> Float) . B.unpack) . take 3 . B.words . head . B.lines
+
+-- | Retrieves load information.  Returns the monitor string parsed
+-- according to template (either default or user specified).
+runLoad :: [String] -> Monitor String
+runLoad _ = do
+  let file = "/proc/loadavg"
+  exists <- io $ fileExist file
+  if exists then
+      (do l <- io $ B.readFile file >>= return . parseLoadAvgs
+          parseTemplate =<< mapM (showWithColors $ showDigits 2) l)
+    else
+      return "Load: N/A"