New submission from Tom Hale <tomn...@gmail.com>:
I cannot find a race-condition-free way to force overwrite an existing symlink. os.symlink() requires that the target does not exist, meaning that it could be created via race condition the two workaround solutions that I've seen: 1. Unlink existing symlink (could be recreated, causing following symlink to fail) 2. Create a new temporary symlink, then overwrite target (temp could be changed between creation and replace. The additional gotcha with the safer (because the attack filename is unknown) option (2) is that replace() may fail if the two files are on separate filesystems. I suggest an additional `force=` argument to os.symlink(), defaulting to `False` for backward compatibility, but allowing atomic overwriting of a symlink when set to `True`. I would be willing to look into a PR for this. Prior art: https://stackoverflow.com/a/55742015/5353461 ---------- messages: 340474 nosy: Tom Hale priority: normal severity: normal status: open title: Allow os.symlink(src, target, force=True) to prevent race conditions versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36656> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
