New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
os.path.isdir returns true for dots #75897
Comments
I uploaded this as a question on Stack Overflow and I suspect it might be a bug. Here is the link for the Stack Overflow question: https://stackoverflow.com/questions/46608731/python-os-path-isdir-returns-true-for-dots/46608842#46608842 The problem itself (copied from what I uploaded on Stack Overflow): I'm programming my own shell in python. Right now I'm trying to implement the The function that performs this command has several variables:
Here is my code: def command_cd(self, dir):
if os.path.isdir(self.shell.current_dir + dir):
self.shell.current_dir = self.shell.current_dir + dir + "\\" The problem is that for some strange reason, The problem occurs even if you change the amount of dots (even above 5 dots) and I really have no idea what causes it. There's obviously no folder named **If my problem isn't clear enough please comment and I'll edit it** |
This is standard Windows API behavior for the final path component. A single dot component means the current directory. Two dots means the parent directory. More than two dots and/or trailing spaces, gets reduced to a single dot, meaning the current directory. For example: >>> os.path.abspath('.')
'C:\\Temp'
>>> os.path.abspath('..')
'C:\\'
>>> os.path.abspath('...')
'C:\\Temp'
>>> os.path.abspath('... ... ...')
'C:\\Temp' Specifically, os.path.isdir is implemented as nt._isdir, which calls WinAPI GetFileAttributes to check for FILE_ATTRIBUTE_DIRECTORY, which in turn calls the NT system function NtQueryAttributesFile. GetFileAttributes has to translate the DOS path to an NT kernel path. In the kernel, none of this "." business exists. The kernel doesn't even have a concept of a working directory. Depending on your Windows version, it might call the runtime library function RtlDosPathNameToNtPathName_U_WithStatus to convert the path to a native OBJECT_ATTRIBUTES record. The first step is to normalize the path via RtlGetFullPathName_Ustr, which is what the Windows API GetFullPathName function calls like in the above abspath() examples. |
Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.
Show more details
GitHub fields:
bugs.python.org fields:
The text was updated successfully, but these errors were encountered: