WinSCP cannot overwrite file without write permissions to containing directory

Question

I want to overwrite a file having permissions 777 but the directory in which file is placed has permissions 755. So it is not allowing to do so.

Answer 1

I suggest changing the permissions on the directory.

A short recap of your post with irrelevant parts left out:
I want to WRITE a file ... to a directory which is not writable for anyone bar the users. I am assuming that you are not logged in as that specific user.

That is, the 755 rights are:

• User: read (r), write (w) , cd into directory (x)
• group: read (r),cd into directory (x)
• other: read (r),cd into directory (x)

Ergo only the user which own the directory is allowed to write to it. You might want to replace a writable file in that directory but that is the same as writing to a public dairy (777, not locked) in a locked cabinet. It fails because the cabinet is locked.

(If you think: why should I write to the directory and not just the file: The directory will be updated with things like last accessed, size, ....)

Other things which I assumed:

1. You are not using ACL.
2. This is not some special folder (such as /dev, /proc, ....)

Answer 2

Your question is pretty vague.

But I would assume you are having the problem because WinSCP tries to transfer to a temporary file first, what conflicts with your lack of create-file permissions.

Turn off Transfer Resume/Transfer to Temporary Filename preference option in WinSCP:
https://winscp.net/eng/docs/ui_pref_resume