Create a WiFi QR code as a PDF or printout

create-wifi-qr-code-sign.py

#!/usr/bin/env python3

"""Create a wifi QR code as a PDF or printout.

This script creates a small sign showing a WiFi network name (SSID) and
password along with a QR code encoding this information in a format which
allows Android devices to connect automatically to the network by scanning
the code.

Requires: pdflatex, qrencode

By Pontus Lurcock, 2019. Released into the public domain.
"""

from tempfile import TemporaryDirectory
import argparse
import subprocess
import os.path
import shutil


def main():
    parser = argparse.ArgumentParser(
        description="Create a WiFi QR code as a PDF or printout. "
        "If no filename or device specified, prints to the default printer.")

    parser.add_argument("--output", "-o", metavar="filename",
                        help="write PDF to specified file")
    parser.add_argument("--printer", "-p", metavar="printer-id",
                        help="print to specified printer")
    parser.add_argument("network", type=str)
    parser.add_argument("password", type=str)
    args = parser.parse_args()
    with TemporaryDirectory() as tempdir:
            make_label(args, tempdir)


def make_label(args, tempdir):
    with open(os.path.join(tempdir, "sign.tex"), "w") as fh:
        fh.write(template % (args.network, args.password))

    wifi_code = "WIFI:T:WPA;S:%s;P:%s;;" % (args.network, args.password)
        
    subprocess.call(["qrencode", "-t", "eps", "-o", "qr-image.eps",
                     "-m", "3", wifi_code], cwd=tempdir)
    subprocess.call(["pdflatex", "sign.tex"],
                    cwd=tempdir)
    subprocess.call(["pdflatex", "sign.tex"],
                    cwd=tempdir)
    if args.output:
        shutil.copy2(os.path.join(tempdir, "sign.pdf"),
                     args.output)
    if args.printer:
        subprocess.call(["lp",
                         "-d", args.printer,
                         os.path.join(tempdir, "sign.pdf")])
    if (not args.output) and (not args.printer):
        subprocess.call(["lp",
                         os.path.join(tempdir, "sign.pdf")])


template = r"""
\documentclass[a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[sfdefault]{AlegreyaSans}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\begin{document}
\setlength{\unitlength}{1mm}
\fontsize{5mm}{8mm}\selectfont
\framebox(60,40){\shortstack{Netzwerk: %s\\
  \includegraphics[height=25mm]{qr-image}\\  
Passwort: %s}}
\end{document}
"""

if __name__ == "__main__":
    main()