cd subdir && $(MAKE) targets -> $(MAKE) -C subdir targets

- first step towards parallel building

test/Makefile

@@ -39,7 +39,7 @@ $(ROOTOBJ):
 	@rm a.out
 
 clean:	
-	cd select && make clean
+	$(MAKE) -C select clean
 	-rm -rf *.o *.s *.bak test? test?? test??-gcc t10a t11a t11b \
 		t40a t40b t40c t40d t40e t40f t43 DIR*
 

test/ipc/Makefile

@@ -17,15 +17,15 @@
 #
 
 all test clean:
-#	cd ./msgctl && $(MAKE) $@
-#	cd ./msgget && $(MAKE) $@
-#	cd ./msgrcv && $(MAKE) $@
-#	cd ./msgsnd && $(MAKE) $@
-	cd ./semctl && $(MAKE) $@
-	cd ./semget && $(MAKE) $@
-	cd ./semop && $(MAKE) $@
-	cd ./shmat && $(MAKE) $@
-	cd ./shmctl && $(MAKE) $@
-	cd ./shmdt && $(MAKE) $@
-	cd ./shmget && $(MAKE) $@
-	cd ./shmt && $(MAKE) $@
+#	$(MAKE) -C ./msgctl $@
+#	$(MAKE) -C ./msgget $@
+#	$(MAKE) -C ./msgrcv $@
+#	$(MAKE) -C ./msgsnd $@
+	$(MAKE) -C ./semctl $@
+	$(MAKE) -C ./semget $@
+	$(MAKE) -C ./semop $@
+	$(MAKE) -C ./shmat $@
+	$(MAKE) -C ./shmctl $@
+	$(MAKE) -C ./shmdt $@
+	$(MAKE) -C ./shmget $@
+	$(MAKE) -C ./shmt $@