SUBDIRS = client-tool server-tool 
  
RECURSIVE_MAKE = @for subdir in $(SUBDIRS); do \
                 echo "making in $$subdir"; \
                 $(MAKE) -C $$subdir; \
                 done  

RECURSIVE_CLEAN = @for subdir in $(SUBDIRS); do \
                  echo "making in $$subdir"; \
                  $(MAKE) -C $$subdir clean; \
                  done

all:
	$(RECURSIVE_MAKE) 
clean:
	$(RECURSIVE_CLEAN)