Creating a simple makefile. Why doesn't the clean target work?

Question

GNU Make

I'm learning the make utility. As an example, I threw the following simple example in the makefile:

.PHONY: all clean

all: hello

clean:
  rm -rf hello *.o

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

hello: main.o
  g++ -o hello main.o

I can’t understand why clean doesn’t work (the object file main.o appears in the folder).
Tell me what I'm doing wrong?!

Answer 1

Most likely you do not specify the target explicitly. By default, the first target is executed (except for those that start with a period) - and in this target (all) there is no clean in the dependencies.
www.gnu.org/software/make/manual/make.html#How-Mak...
And .PHONY is used to bypass file name and script match (try removing clean from .phony, create clean file and do make clean)
https://www.gnu.org/software/make/manual/html_node...