I want to use std::filesystem to query about a disk folder path that was given to my function. I want to find out if I have write access to the folder. But I want to do it without actually trying to write to the folder.
This last requirement is partly because
- a) I don't want to change the filesystem's last-written-to time on the folder
- b) I want to learn how to do this merely by querying the filesystem in some sort of platform-independent fashion, if possible
It would appear that std::filesystem::status() is the function that I want. However the permissions flags returned by that function include owner_write, group_write and others_write.
How do I tell which of these applies to me? I don't know if my application/user is the owner, the group or the "other". Is there some sort of can_i_write_to_this_folder() function kicking around somewhere?
The only thread I could find related to this has no answer that involves <filesystem>
[Edit] People appear to be under the impression that I'm looking for some unrealistic guarantee of write-ability. I'm not. I'm not under the illusion that any filesystem function is foolproof. I'm not basing some mission-critical system upon this decision
When <filesystem> came around and gave us all directory_iterator and other goodies, their advertised purpose was useful. So I evaluated them and used them, when I found that to be true. Just as I did for std::atomic<> and parameter packs and std::variant and a host of other things. I think we can all agree there are a few things added over the years that have proved not to be that great.
Now the library advertises this function, filesystem::status() that purports to tell us (among other things) the permissions on a file or folder. I want to find out if this "access" information is of any practical use.
The consensus seems to be that it is not.