I have makefile and I'm confused about what this command does
build:
mkdir -p $@
%: build/%
cp $< $@
Can any body explain it?
1 Answers
The makefile defines two rules: build and a pattern rule. The build rule simply creates a directory called build (note: $@ expands to the name of the target -- see Automatic Variables).
The second rule is a pattern rule. The pattern here is %, which matches anything. That target is dependent on build/% where the % is the target name. (so foo would be dependent on build/foo for example). If the dependency exists or can be built, foo would be created by copying the first dependency ($< expands to the first dependency which would be build/foo) to foo.
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