Support staged installations

Makefile

@@ -4,12 +4,12 @@ CFLAGS += -Wall -Wextra -O3 -march=native
 prefix = /usr/local
 backlight_dir = /sys/class/backlight/intel_backlight/
 max_brightness = $(shell cat $(backlight_dir)max_brightness)
-backlight_rule = $(USER) ALL=NOPASSWD: $(prefix)/bin/backlight_control
+backlight_rule = ALL ALL=NOPASSWD: $(prefix)/bin/backlight_control
 
 DEFINES += -D BACKLIGHT_DIR=\"$(backlight_dir)\"
 DEFINES += -D MAX_BRIGHTNESS=$(max_brightness)
 
-all: install
+all: backlight_control
 
 %: %.c
 	$(CC) $(CFLAGS) $(DEFINES) $< -o $@
@@ -18,9 +18,9 @@ clean:
 	rm -f backlight_control
 
 install: backlight_control
-	echo $(backlight_rule) | sudo tee /etc/sudoers.d/backlight
-	sudo mv $< $(prefix)/bin
+	mv $< $(DESTDIR)$(prefix)/bin
+	tee $(DESTDIR)/etc/sudoers.d/backlight <<< "$(backlight_rule)"
 
 uninstall:
-	sudo rm -f /etc/sudoers.d/backlight
-	sudo rm -f $(prefix)/bin/backlight_control
+	rm -f $(DESTDIR)$(prefix)/bin/backlight_control
+	rm -f $(DESTDIR)/etc/sudoers.d/backlight

README.md

@@ -5,17 +5,17 @@ I had some problems with `xbacklight` in combination with the proprietary nvidia
 
 ## Build
 ```sh
-make backlight_control
+make
 ```
 
 ## Install
 ```sh
-make install
+sudo make install
 ```
 
 ## Uninstall
 ```sh
-make uninstall
+sudo make uninstall
 ```
 
 ## Usage