On 8/25/20, Andrew Nelson <andyf...@gmail.com> wrote: > > st_ino is supposed to "uniquely identify the file for a given value of > st_dev."
That assurance only applies to POSIX systems, not Windows. st_ino is the file ID in Windows. Some filesystems do not support reliable file IDs, if any at all. I would only rely on the st_ino value if the filesystem flags include FILE_SUPPORTS_OPEN_BY_FILE_ID. You can get the filesystem flags via GetVolumeInformationByHandleW, using a handle for any file in the filesystem. For example, FAT filesystems use a semi-stable file ID, which is based on a file's byte offset in the parent directory. This offset can can change if the filesystem is defragmented, so FAT file IDs are unreliable. This is probably why FAT filesystems do not support opening by file ID. Another example is the WebDAV filesystem, which doesn't support file IDs at all, so the value is 0 for all files. st_dev is the volume serial number (VSN) in Windows. Like the file ID, filesystems are not required to support a VSN, in which case it may be 0 (e.g. it's 0 for WebDAV). Even if the VSN is supported, Windows does not guarantee that the value is unique. It's a random 32-bit number, so it's unlikely that a non-zero value isn't unique, but there's no hard guarantee. -- https://mail.python.org/mailman/listinfo/python-list
