GNU make simple usage example

Requirement: Write a Makefile to compile and link the two .cpp files to generate the executable file main. The cpp file can be found at the following link:

https://blog.csdn.net/Reading8/article/details/132630694https://blog.csdn.net/Reading8/article/details/132630694 a>There are two ways to compile and link this example to generate an executable file.

One is the command line method

(base) ganning@ganning:~/Xproject/makefilesteel$ g++ main.cpp myfunctions.cpp -o main
(base) ganning@ganning:~/Xproject/makefilesteel$ ls
main  main.cpp  myfunctions.cpp  myfunctions.h
(base) ganning@ganning:~/Xproject/makefilesteel$ ./main
Hello world!

Another way to write a Makefile

main: main.o myfunctions.o
	g++ main.o myfunctions.o -o main


main.o: main.cpp
	g++ -c main.cpp

myfunctions.o: myfunctions.cpp myfunctions.h
	g++ -c myfunctions.cpp
	
clean:
	rm *.o 

Note that in < g++ -c main.cpp > -c means not to generate an executable file, <rm *.o> means to delete all .o suffix files. You can use make clean to call this operation. You can see the Makefile The basic writing specification is

target： materials
    Operation

Result verification

(base) ganning@ganning:~/Xproject/makefilesteel$ make
g++ -c main.cpp
g++ -c myfunctions.cpp
g++ main.o myfunctions.o -o main
(base) ganning@ganning:~/Xproject/makefilesteel$ ls
main  main.cpp  main.o  Makefile  myfunctions.cpp  myfunctions.h  myfunctions.o
(base) ganning@ganning:~/Xproject/makefilesteel$ ./main
Hello world!
(base) ganning@ganning:~/Xproject/makefilesteel$ make clean
rm *.o 
(base) ganning@ganning:~/Xproject/makefilesteel$ ls
main  main.cpp  Makefile  myfunctions.cpp  myfunctions.h