graph-deps.py

#!/usr/bin/env python
# file: graph-deps.py
# vim:fileencoding=utf-8:ft=python
#
# Copyright © 2017-2018 R.F. Smith <rsmith@xs4all.nl>.
# SPDX-License-Identifier: MIT
# Created: 2017-04-27T14:20:52+02:00
# Last modified: 2021-12-19T10:45:28+0100
"""
Creates a graph of FreeBSD package dependencies. Requires Python 3 as python.

Use it like this:

    pkg info -dx py39- | python graph-deps.py | dot -o py39-deps.pdf -Tpdf

This will output a graphviz digraph for all Python 3.9 packages on stdout,
which is processed by the “dot” program from the graphics/graphviz port and
turned into a PDF rendering of the graph.
"""

import sys

if len(sys.argv) > 1 and sys.argv[1] in ("-h", "--help"):
    print(__doc__)
    exit(0)
output = [
    "digraph deps {",
    "rankdir=LR;",
    'fontname="Alegreya";',
    "concentratr=true;",
    'node [shape=box, fontname="Alegreya"];',
]
parent = None
try:
    for ln in sys.stdin:
        pkgname = ln.strip()
        if pkgname.endswith(":"):
            pkgname = pkgname[:-1]
        output.append(f'"{pkgname}" [label="{pkgname}"];')
        if ln[0] not in " \t":  # parent
            parent = pkgname
        else:
            output.append(f'"{parent}" -> "{pkgname}";')
except KeyboardInterrupt:
    print("\n", __doc__)
else:
    print("\n".join(output) + "}")