LaTeX file path as command line argument to SVG on stdout in the worst possible version (impure)

latex-to-svg.py

#!/usr/bin/env python
# Takes a filename of a LaTeX file as argv[1] and prints the resulting svg on
# stdout. Impure, depends on pdflatex and pdf2svg, creates a temporary dir.
import re
import subprocess
import sys
import tempfile
from pathlib import Path


SEARCH_AND_REPLACE = [
    # actually utilize all that width available instead of squishing everything together
    ('width=".*" height=".*" viewbox=".*"', 'width="100%"'),
    # fix up the fill which is always either empty or black, for some reason
    # this way the SVG actually responds to the mdbook theme
    ('fill=".*"', 'style="fill: var(--fg)"'),
]


def latex_to_svg(source: Path) -> str:
    with tempfile.TemporaryDirectory() as tmpdir:
        tmpdir = Path(tmpdir)
        svg_file = tmpdir / "lol.svg"

        # perform the actual compilation
        mute_args = {
            "stdin": subprocess.DEVNULL,
            "stdout": subprocess.DEVNULL,
            "stderr": subprocess.DEVNULL,
        }
        subprocess.run(
            ["pdflatex", f"-output-directory={tmpdir}", source.resolve()], **mute_args
        )
        subprocess.run(
            ["pdf2svg", (tmpdir / source.stem).with_suffix(".pdf"), svg_file],
            **mute_args,
        )

        with open(svg_file) as fh:
            content = fh.read()

        for search, replace in SEARCH_AND_REPLACE:
            content = re.sub(search, replace, content)

    return content


def panic(message: str):
    print(message, file=sys.stderr)
    sys.exit(1)


def main(argv: list):
    latex_source_path = (
        Path(argv[1])
        if argv[1:]
        else panic("please give me one argument as path to a latex file")
    )

    svg_content = latex_to_svg(latex_source_path)

    sys.stdout.write(svg_content)
    sys.stdout.flush()  # not sure if this has even any effect, tbh


if __name__ == "__main__":
    main(sys.argv)