Add install rule to Makefile

Makefile

@@ -1,9 +1,8 @@
-CC = clang
 CFLAGS = -fPIC -Wall -Wextra -O
 LDFLAGS = -shared
+PREFIX ?= /usr
 
-.PHONY: all clean
-
+.PHONY: all
 all: libbuse.so
 
 libbuse.so: buse.o
@@ -12,5 +11,13 @@ libbuse.so: buse.o
 buse.o: buse.c
 	$(CC) $(CFLAGS) -c -o $@ $^
 
+.PHONY: install
+install: libbuse.so
+	mkdir -p $(DESTDIR)$(PREFIX)/lib
+	mkdir -p $(DESTDIR)$(PREFIX)/include
+	cp libbuse.so $(DESTDIR)$(PREFIX)/lib/
+	cp buse.h $(DESTDIR)$(PREFIX)/include/
+
+.PHONY: clean
 clean:
-	rm -f buse.o libbuse.so
+	$(RM) buse.o libbuse.so