/_drafts/%.mdを、/%.htmlに変換する。テンプレートファイル_template._templateは、変換するmdごとに、同じフォルダにあればそれを、なければその上のフォルダを探してそれを、そこにもなければさらに上を……と探索する。

Makefile

####################
# markdown to html
# (For Windows)
####################
DRAFTS_DIR_NAME := _drafts
SITE_ROOT_DIR := $(shell cd)
# template file
TEMPLATE_EXT := _template
TEMPLATE_FILE := _template.$(TEMPLATE_EXT)

# markdown source files
SOURCE_MD := $(subst $(SITE_ROOT_DIR)\,,$(shell dir /A-D /B /S $(DRAFTS_DIR_NAME)\*.md))
# target html files
DEST_HTML := $(subst $(DRAFTS_DIR_NAME)\,,$(SOURCE_MD:.md=.html))
# vpath for markdown source files
vpath %.md $(DRAFTS_DIR_NAME)


####################
# functions
####################
# Get parent folder
Parent = $(subst $(SITE_ROOT_DIR)\,,$(subst /,\,$(dir $(abspath $(subst \,/,$(1))))))
# Return file path if it exsists, return empty if not
GetExistFile = $(if $(shell dir /A-D /B $(1) 2>NUL),$(1),)
# Return directory path if it exsists, return empty if not
GetExistFolder = $(if $(shell dir /AD $(1) 2>NUL),$(1),)
# Make template file path from base path
MakeTempPath = $(DRAFTS_DIR_NAME)\$(call Parent,$(1))$(TEMPLATE_FILE)
# Find template path from html file path
FindTemplate = $(if $(1),$(if $(call GetExistFile,$(call MakeTempPath,$(1))),$(call MakeTempPath,$(1)),$(call FindTemplate,$(call Parent,$(1)))),)
# Filter markdown source file from prerequisite list
PickMD = $(subst /,\,$(firstword $(filter %.md,$(1))))
# Filter template file from prerequisite list
PickTMP = $(subst /,\,$(firstword $(filter %.$(TEMPLATE_EXT),$(1))))


####################
# rules
####################
.PHONY: all
all: ${DEST_HTML}

.SECONDEXPANSION:
%.html: %.md $$(call FindTemplate,$$@)
	@echo Build $@
	-@mkdir $(call Parent,$@)
	@nkf -w8 $(call PickMD,$^) | pandoc --template $(call PickTMP,$^) -f markdown+east_asian_line_breaks -o $@