Makefile with loops

Makefile

OS = $(shell uname -s)
CONFIGS = $(wildcard *.js)
empty =
tab = $(empty)$(shell printf '\t')$(empty)

define execute-command
$(tab)$(1)

endef

what = $(foreach a,$(CONFIGS),./bin/dnscontrol-$(OS) -js $(a) preview${\n})

fetch-binary: ## fetch dns control binary for your OS
        @echo "Please wait while fetching your binary. It will be placed in bin/"
        @mkdir -p bin
        @curl -s -o bin/dnscontrol-$(OS) -L https://github.com/StackExchange/dnscontrol/releases/download/latest/dnscontrol-$(OS)

preview: ## preview changes for all files
        @$(foreach a,$(CONFIGS),$(call execute-command,./bin/dnscontrol-$(OS) -js $(a) preview))

push: ## push changes for all files
        @$(foreach a,$(CONFIGS),$(call execute-command,./bin/dnscontrol-$(OS) -js $(a) push))


.PHONY: help preview
.DEFAULT_GOAL := help

help:
        @grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'