usage:
	@echo "make nolib | static | dynamic"

%.o: %.c
	gcc -c -fPIC -g -Wall $<

nolib: main.o util.o
	gcc -g -o main main.o util.o


static: libutil.a main.o
	gcc -o main main.o -L. -lutil

libutil.a: util.o
	ar rcs libutil.a util.o


# use "ldd main" to see the shared objects used by main
dynamic: main.o libutil.so.1 solink
	gcc -o main main.o -L. -lutil

libutil.so.1: util.o
	gcc -shared -Wl,-soname,libutil.so -o libutil.so.1 util.o -lc

solink:
	ln -sf libutil.so.1 libutil.so

clean:
	rm -f *.a *.o main libutil.so libutil.so.1 *~