make

Make is a powerful build system with the simple concept of transforming files in other files based on a recipe

flowchart LR A[source files] B(( recipe )) C[output files] A --> B --> C

Special chars

The makefile syntax involves some character that expands to specific files when make is executed, such as:

$% the target member name
$@ expands to the target file
$< expands to the first requisite
$^ expands to all requisites

makefile vars

A var in a makefile is defined as follows:

BUILDDIR = ./build

And is referred with the $() notations

mytarget:
  some_long_command $(BUILDDIR)

✔️ ENVIRONMENT variables are automatic exposed with the same notation $(), example $(HOME)

PHONY targets

Phony targets are targets that doesn’t generate any file, they are a useful way to group other targets together

.PHONY: build clean

Examples

makefile with build directory that generates png from mermaid graph files

BUILDDIR = ./build

%.png: %.mmd
	mkdir -p $(BUILDDIR)
	mmdc -i $< -o $(BUILDDIR)/$@

clean:
	rm -rf $(BUILDDIR)

build: $(patsubst %.mmd,%.png,$(wildcard *.mmd))