Rewrite Makefile to accomodate file split

Makefile

@@ -1,25 +1,72 @@
-# See LICENSE file for copyright and license details.
+# See LICENSE file for copyright and license details
 # slstatus - suckless status monitor
 .POSIX:
 
 include config.mk
 
+REQ = util
+HDR = arg.h
+COM =\
+	battery\
+	cpu\
+	datetime\
+	disk\
+	entropy\
+	hostname\
+	ip\
+	kernel_release\
+	keyboard_indicators\
+	load_avg\
+	num_files\
+	ram\
+	run_command\
+	swap\
+	temperature\
+	uptime\
+	user\
+	volume\
+	wifi
+
 all: slstatus
 
-slstatus: slstatus.c config.h config.mk
-	$(CC) -o $@ $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) slstatus.c $(LDLIBS)
+slstatus: slstatus.o $(COM:=.o) $(REQ:=.o)
+slstatus.o: slstatus.c slstatus.h $(HDR) $(REQ:=.h)
 
-config.h:
-	cp config.def.h $@
+battery.o: battery.c config.mk $(HDR) $(REQ:=.h)
+cpu.o: cpu.c config.mk $(HDR) $(REQ:=.h)
+datetime.o: datetime.c config.mk $(HDR) $(REQ:=.h)
+disk.o: disk.c config.mk $(HDR) $(REQ:=.h)
+entropy.o: entropy.c config.mk $(HDR) $(REQ:=.h)
+hostname.o: hostname.c config.mk $(HDR) $(REQ:=.h)
+ip.o: ip.c config.mk $(HDR) $(REQ:=.h)
+kernel_release.o: kernel_release.c config.mk $(HDR) $(REQ:=.h)
+keyboard_indicators.o: keyboard_indicators.c config.mk $(HDR) $(REQ:=.h)
+load_avg.o: load_avg.c config.mk $(HDR) $(REQ:=.h)
+num_files.o: num_files.c config.mk $(HDR) $(REQ:=.h)
+ram.o: ram.c config.mk $(HDR) $(REQ:=.h)
+run_command.o: run_command.c config.mk $(HDR) $(REQ:=.h)
+swap.o: swap.c config.mk $(HDR) $(REQ:=.h)
+temperature.o: temperature.c config.mk $(HDR) $(REQ:=.h)
+uptime.o: uptime.c config.mk $(HDR) $(REQ:=.h)
+user.o: user.c config.mk $(HDR) $(REQ:=.h)
+volume.o: volume.c config.mk $(HDR) $(REQ:=.h)
+wifi.o: wifi.c config.mk $(HDR) $(REQ:=.h)
+
+.o:
+	$(CC) -o $@ $(LDFLAGS) $< $(COM:=.o) $(REQ:=.o) $(LDLIBS)
+
+.c.o:
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 clean:
-	rm -f slstatus
+	rm -f slstatus slstatus.o $(COM:=.o) $(REQ:=.o)
 
 dist:
 	rm -rf "slstatus-$(VERSION)"
 	mkdir -p "slstatus-$(VERSION)"
-	cp -R arg.h config.def.h config.mk LICENSE Makefile README slstatus.1 \
-		slstatus.c slstatus.png "slstatus-$(VERSION)"
+	cp -R LICENSE Makefile README config.mk config.def.h \
+	      $(HDR) slstatus.c $(COM:=.c) $(REQ:=.c) $(REQ:=.h) \
+	      slstatus.1 "slstatus-$(VERSION)"
 	tar -cf - "slstatus-$(VERSION)" | gzip -c > "slstatus-$(VERSION).tar.gz"
 	rm -rf "slstatus-$(VERSION)"