``siemens-qu-pr-decode`` is utility for decode Quoted-Printable (old Siemens non-standard dialect)

decode.sh

#!/usr/bin/bash

out_file="decode-out.txt"
decode_filter="$(dirname -- "$0")/siemens-qu-pr-decode"

echo "# $(date)" >"$out_file"

for arg
do
    echo "--------------------------------------------------">>"$out_file"
    cat -- "$arg" | "$decode_filter" >>"$out_file"
done

siemens-qu-pr-decode

#!/usr/bin/python3
# -*- mode: python; coding: utf-8 -*-
#
# Copyright 2013 Andrej A Antonov <[email protected]>.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

assert str is not bytes

import argparse, sys, re

magic_str = b'CHARSET=UTF-8;ENCODING=QUOTED-PRINTABLE:'
regex = re.compile(re.escape(magic_str) + br'|=(?P<char>[0-9A-Fa-f]{2}|\r\n|\n)|\r\n', re.S)

def decode_func(matchobj):
    if matchobj.group('char') is not None:
        if matchobj.group('char') in (b'\r\n', b'\n'):
            return
        
        return bytes((int(matchobj.group('char'), base=16),))
    
    if matchobj.group() == magic_str:
        return
    
    if matchobj.group() == b'\r\n':
        return b'\n'

def decode(in_text):
    out_text = regex.sub(decode_func, in_text)
    
    return out_text

def main():
    parser = argparse.ArgumentParser(
            description="utility for decode Quoted-Printable (old Siemens non-standard dialect)")
    
    args = parser.parse_args()
    
    ifd = sys.stdin.buffer
    ofd = sys.stdout.buffer
    
    in_text = ifd.read()
    out_text = decode(in_text)
    ofd.write(out_text)
    ofd.flush()

if __name__ == '__main__':
    main()