Question

What are the prerequisites in the following makefile rule?

store: main.o store.o
          $(CXX) $(CXXFLAGS) -o store main.o store.o

	A.	main.o store.o
	B.	store
	C.	$(CXXFLAGS)
	D.	$(CXX) $(CXXFLAGS) -o store main.o store.o

Answer 1

Answer  : The prerequisites in the following makefile rule

store: main.o store.o
          $(CXX) $(CXXFLAGS) -o store main.o store.o

is A. main.o store.o.

Explanation :

• A simple makefile rule consists of format :

target ....... : prerequisites ........
recipe
   ...
   .....

• store is a target file. A target is usually a file that is generated by a program or name of an action that you want to carry out.
• main.o store.o is the prerequisites. A prerequisite is an input file that is used to create a target file. There can be many prerequisites that can be used for creating target file.
• $(CXX) $(CXXFLAGS) are the variables. Variables are used to store text string which is defined once and they can then be substituted in program later. The use of variable to access it in program is in format $(variable_name).
• -o store main.o store.o is recipe. A recipe is a rule with prerequisite which serves to create target file if any of the prerequisites change.
• Above all explanation ,the last option is eliminated already.