example of GNU make builtin functions

Makefile

YAML:=hoge.yaml
FILES:=$(YAML) fuga.tar.gz ./foo/bar.json

all: \
        abspath \
        addprefix \
        addsuffix \
        basename \
        dir \
        notdir \
        realpath \
        subst \
        shell \
        info \
        warning \
        if \
        foreach
.PHONY: \
        all \
        abspath \
        addprefix \
        addsuffix \
        basename \
        dir \
        notdir \
        realpath \
        subst \
        shell \
        info \
        warning \
        if \
        foreach

abspath:
        @echo $@
        @echo $(abspath .)
        @echo

addprefix:
        @echo $@
        @echo $(addprefix xxx,$(FILES))
        @echo

addsuffix:
        @echo $@
        @echo $(addsuffix xxx,$(FILES))
        @echo

basename:
        @echo $@
        @echo $(basename $(FILES))
        @echo

dir:
        @echo $@
        @echo $(dir $(FILES))
        @echo

notdir:
        @echo $@
        @echo $(notdir $(FILES))
        @echo

realpath: $(YAML)
        @echo $@
        @echo $(realpath $(FILES))
        @echo

subst:
        @echo $@
        @echo $(subst .json,.txt,$(FILES))
        @echo

shell:
        @echo $@
        @echo $(shell ls)
        @echo

info:
        @echo $@
        @echo $(info "this function is for print debug of Makefile")
        @echo

warning:
        @echo $@
        @echo $(warning "warning")
        @echo

foreach:
        @echo $@
        @echo $(foreach f,$(FILES),"$(f)\n")
        @echo

if:
        @echo $@
        @echo $(if a,not empty,empty)
        @echo $(if  ,notempty,empty)
        @echo

$(YAML):
        touch $@