Build a dependency graph of selected formulae

Makefile

# Build a dependency graph of selected formulae

.DELETE_ON_ERROR:
.SECONDARY:
.PHONY: all

all: cxx.deps.unisolated.gv.tsort.txt cxx.deps.unisolated.pdf

# Generate the dependencies of a list of formula
%.deps.tsv: %.txt
	for i in `<$<`; do \
		for j in `brew deps $$i`; do \
			printf "%s\t%s\n" $$i $$j; \
		done; \
	done >$@

# Convert a TSV file of dependencies to GraphViz
%.gv: %.tsv
	( \
		echo 'digraph {' ; \
		cut -f1 $< | sort -u | sed 's/.*/"&" [cxx=1]/'; \
		awk '{ print "\"" $$2 "\" -> \"" $$1 "\"" }' <$<; \
		echo '}' \
	) | gvpr -i 'N[cxx]' | tred >$@

# Remove isolated vertices.
%.unisolated.gv: %.gv
	gvpr 'E[1]' $< >$@

# Extract vertex names from a GraphViz file.
%.gv.txt: %.gv
	gvpr 'N{ print(name) }' $< | sort >$@

# Convert a GraphViz file to a TSV file.
%.gv.tsv: %.gv
	gvpr 'E{ print(tail, "\t", head) }' $< >$@

# Topological sort a TSV file.
%.tsort.txt: %.tsv
	tsort $< >$@

# Render a GraphViz file to PDF.
%.pdf: %.gv
	dot -Tpdf -o $@ $<