Windows 11 Python and Windows File System Permissions

Josephur

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What is the best way to read a files owner and permissions, create a new file then apply those permissions without using the subprocess method or command line icacls etc.
 
The best way to handle file permissions and ownership is to use the built-in Python libraries like os and shutil. In order to read file permissions and ownership, you should use the following code:
Code:
import os import stat file_path = 'yourfile.txt' # get file permissions file_info = os.stat(file_path) file_permissions = stat.S_IMODE(file_info.st_mode) # get owner id owner_id = file_info.st_uid
In the above code, st_mode contains information about file permissions, which you get using stat.S_IMODE. st_uid attribute is for user id who owns the file. To create a new file via Python, you can use the open() function:
Code:
new_file_path = 'new_file.txt' # create a new file open(new_file_path, 'a').close()
To apply the read permissions to a newly created file, you can use the os.chmod() method and ownership by os.chown() method:
Code:
# applying permissions os.chmod(new_file_path, file_permissions) # applying onwership os.chown(new_file_path, owner_id, -1)
The above code applies the same permissions as the original file to the new file. Note that you need superuser privileges to change the owner of the file. Please be aware that managing file permissions and ownership is a sensitive task and always make sure to verify your actions to avoid security issues. Remember that this code sample will work fine on Unix-based systems like Linux and macOS. However, on Windows, Python's os.chmod doesn't support all permissions and os.chown function is not available in Python for Windows. In case you are working on Windows, you have to approach it differently, perhaps by using libraries that support Windows ACLs, like pywin32 or win32security as working with file permissions on Windows is more complicated due to the Access Control Lists (ACLs).
 
I get an error,
Traceback (most recent call last):
File "C:\Temp\test.py", line 27, in <module>
os.chown(new_file_path, owner_id, -1)
^^^^^^^^
AttributeError: module 'os' has no attribute 'chown'
 
@ChatGPT Shouldn;'t it use PowerShell since that has native integration with Microsoft Windows and PS5 is included with every copy of Windows?
 
The error indicates that you’re attempting to use the os.chown() function in Python, but the error happens because Windows does not support the chown attribute in the os module. The os.chown() method is specific to Unix-like operating systems (e.g., Linux, macOS), and it doesn’t exist on Windows, as Windows handles file ownership differently.

How to Address This on Windows:​

  1. Understand Windows File Permissions:
    • Windows uses ACLs (Access Control Lists) to manage file ownership and permissions, not Unix-style chown.
  2. Alternative Approach on Windows:
    • To change ownership in Python on Windows, you’ll need to use additional libraries or call Windows-specific commands.
    • Here's how you can proceed:

Solution 1: Use icacls Command in Subprocess​

You can execute the Windows built-in icacls command to modify ownership of a file or folder.

Example Code:​

Python:
import subprocess def take_ownership(file_path, owner): try: subprocess.run(["icacls", file_path, "/setowner", owner], check=True) print(f"Ownership of {file_path} changed to {owner}") except subprocess.CalledProcessError as e: print(f"Error taking ownership of {file_path}: {e}") # Usage: file_path = "C:\\Temp\\example_file.txt" owner = "YOUR-PC\\YourUsername" # Replace with your user take_ownership(file_path, owner)
This uses icacls to set the ownership of the file. Be sure to replace "YOUR-PC\\YourUsername" with your actual user account in Windows.

Solution 2: Use pywin32 for File Ownership (Advanced)​

The pywin32 library provides a Python interface to Windows APIs, including file/directory ownership.

Example Code:​

Python:
import win32security import ntsecuritycon as con def set_owner(file_path, new_owner): # Lookup the user SID sd = win32security.GetFileSecurity(file_path, win32security.OWNER_SECURITY_INFORMATION) sid, _ = win32security.LookupAccountName(None, new_owner) # Set the new owner sd.SetSecurityDescriptorOwner(sid, 0) win32security.SetFileSecurity(file_path, win32security.OWNER_SECURITY_INFORMATION, sd) print(f"Ownership of {file_path} changed to {new_owner}") # Usage: file_path = "C:\\Temp\\example_file.txt" new_owner = "YOUR-PC\\YourUsername" # Replace with your Windows username set_owner(file_path, new_owner)
  • Install pywin32: This requires the pywin32 package. Install it via:
    Code:
    sh pip install pywin32

Solution 3: Skip Ownership​

If file ownership does not need to be explicitly altered, you can simply modify file permissions using the os.chmod() method, which works on both Unix and Windows to set read/write access.

Example Code:​

Python:
import os file_path = "C:\\Temp\\example.txt" os.chmod(file_path, 0o777) # Grants full read/write/execute permissions
  • Note: On Windows, this may get reverted in certain cases because chmod does not fully account for ACL-based permissions.

Final Notes​

  • If you need to manage ACLs (like permission additions beyond ownership), explore Windows-specific tools like the win32security module or third-party packages like pyACL.
  • Let me know if you’d like assistance in setting up any of these solutions or debugging further!
 
Thank you for your feedback! If you have any questions about Python, Windows file system permissions, or even HTML after checking out that tutorial, feel free to ask. I’m here to help with anything technical you need—just let me know what you’d like to dig into!
 
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