Makefile that runs GraphViz Dot utility on all *.gv files in the current directory

Makefile

# Makefile for GraphViz files in this directory
#
# `make all`         - build all targets
# `make clean`       - delete all targets
# `make listtargets` - print list of all targets

# `brew install graphviz`, or download from <http://graphviz.org/download/>
# to get the `dot` utility.
DOT?=dot

# Pattern rules
%.png : %.gv
	$(DOT) -Tpng -o $@ $<
%.svg : %.gv
	$(DOT) -Tsvg -o $@ $<

# Process all *.gv files in this directory, producing .png and .svg output.
SRC_FILES=$(wildcard *.gv)
OUT_FILES=$(SRC_FILES:.gv=.png) $(SRC_FILES:.gv=.svg)

all: $(OUT_FILES)
.PHONY: all

listtargets:
	@echo $(OUT_FILES)
.PHONY: listtargets

clean:
	- $(RM) $(OUT_FILES)
.PHONY: clean