Initial commit

nbackbright.nim

@@ -0,0 +1,37 @@
+import os
+import streams
+import strutils
+
+const
+  BL_SYS_DIR = "/sys/class/backlight"
+
+proc change_brightness(percent: int) =
+  if dirExists(BL_SYS_DIR):
+    for kind, path in walkDir(BL_SYS_DIR):
+      let
+        br_file = path & "/brightness"
+        mb_file = path & "/max_brightness"
+      if fileExists(br_file) and fileExists(mb_file):
+        try:
+          let br_stream = openFileStream(br_file)
+          let br = parseInt(br_stream.readLine())
+          br_stream.close()
+
+          let mb_stream = openFileStream(mb_file)
+          let mb = parseInt(mb_stream.readLine())
+          mb_stream.close()
+
+          var new_br = int(float(br) + float(mb) / 100.0 * float(percent))
+          if new_br < 0: new_br = 0
+          if new_br > mb: new_br = mb
+
+          let br_write = openFileStream(br_file, fmWrite)
+          br_write.writeLine(new_br)
+          br_write.close()
+        except:
+          echo "Fail to interact with ", br_file
+
+when isMainModule:
+  if paramCount() > 0:
+    let percent = parseInt(paramStr(1))
+    change_brightness(percent)