Add brightness adjust program

brightness-adjust.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define ROOT_DIR "/sys/class/backlight/intel_backlight/"
+#define BRIGHTNESS_STEP 750
+
+
+int main(int argc, char** argv) {
+	FILE* brightness = fopen(ROOT_DIR "brightness", "r+");
+	if(brightness == NULL) {
+		perror("fopen");
+		exit(EXIT_FAILURE);
+	}
+
+	int current_brightness;
+
+	int res = fscanf(brightness, "%d", &current_brightness);
+	if(res != 1) {
+		perror("fscanf");
+		exit(EXIT_FAILURE);
+	}
+
+
+	if(argc != 2) {
+		fprintf(stderr, "Exactly one argument is required. Got %d arguments.\n", argc);
+		exit(EXIT_FAILURE);
+	}
+
+	if(*argv[1] == '+') {
+		current_brightness+=BRIGHTNESS_STEP;
+	} else if(*argv[1] == '-') {
+		current_brightness-=BRIGHTNESS_STEP;
+	} else {
+		fprintf(stderr, "Argument must be '+' or '-', got %s.\n", argv[1]);
+		exit(EXIT_FAILURE);
+	}
+
+	if(current_brightness < 0)
+		current_brightness = 0;
+
+	rewind(brightness);
+
+	if(!fprintf(brightness, "%d", current_brightness)) {
+		perror("fprintf");
+		exit(EXIT_FAILURE);
+	}
+
+
+	if(fclose(brightness)) {
+		perror("fclose");
+		exit(EXIT_FAILURE);
+	}
+
+	return 0;
+
+}

xmonad.hs

@@ -123,6 +123,9 @@ main = do
         , ((0, 0x1008ff15), spawn "clementine --stop")
         , ((0, 0x1008ff16), spawn "clementine --restart-or-previous")
         , ((0, 0x1008ff17), spawn "clementine --next")
+	-- Brightness buttons
+	, ((0, 0x1008ff02), spawn "~/.xmonad/brightness-adjust +")
+	, ((0, 0x1008ff03), spawn "~/.xmonad/brightness-adjust -")
         ]
         `additionalKeys`
         --