Makefile

Variables can only be strings. You’ll typically
want to use :=, but = also works.

files := file1 file2
some_file: $(files)
	echo "Look at this variable: " $(files)
	touch some_file

file1:
	touch file1
file2:
	touch file2

clean:
	rm -f file1 file2 some_file

Reference variables using either ${} or $()

x := dude

all:
	echo $(x)
	echo ${x}

	# Bad practice, but works
	echo $x