ADS ntfs

r"""
ADS are alternative data streams of files in NTFS on Windows.

This is just a demonstration, that you can use a regular open
function to write and read this files.


I got the Idea from: https://www.youtube.com/watch?v=vz15OqiYYXo

After you run the programm, you can comment out the write of the file.
Then repeat the process and you'll see the content again.
Then look on your desktop and look if you see more than one file.txt

You can show this files with dir. Here some output from my vm:

C:\Users\andre\Desktop>dir /R

... removed ...

26.03.2021  18:40    <DIR>          .
26.03.2021  18:40    <DIR>          ..
26.03.2021  18:30               632 ads.py
26.03.2021  18:30                 4 file.txt
                                  3 file.txt:bar:$DATA
                                  4 file.txt:buzz:$DATA
                                  4 file.txt:fizz:$DATA
                                  3 file.txt:foo:$DATA
                                  7 file.txt:my_data:$DATA

... removed ...
"""

from pathlib import Path
from typing import Optional


def open_ads(
    file: Path,
    mode: str = "r",
    stream: Optional[str] = None,
    **kwargs,
):
    """
    Open alternate data streams on Windows.

    if stream is None, then the default stream is used,
    which is visible to the user.
    """
    file = str(file)
    if stream:
        file += f":{stream}:$data"
    return open(file, mode, **kwargs)


# place to put the file is yor Desktop with
# the current user, who runs the program
desktop = Path.home() / "Desktop"
text_file = desktop / "file.txt"

# name of streams
# None is a regular file
STREAMS = (None, "my_data", "foo", "bar", "fizz", "buzz")


def write():
    for stream in STREAMS:
        print("Writing to stream", stream or "default")
        with open_ads(text_file, "w", stream=stream) as fd:
            fd.write(stream or "None")


def read():
    for stream in STREAMS:
        print(f"Content of {stream or 'default'} is:", end=" ")
        with open_ads(text_file, stream=stream) as fd:
            print(fd.read())


if __name__ == "__main__":
    print(f"'{text_file}' will be created.", end="\n\n")
    yesno = input("Am I allowed to do this? [y/n]: ")
    if yesno.lower().strip().startswith("y"):
        write()
        print()
    try:
        read()
    except FileNotFoundError:
        print(f"'{text_file}' does not exsit")