File permission: prevent folder owner

[Johnson Punniyalingam]

Is there a way to set the file permission of the a file such that folder owner cannot modify or delete files which he has no such permissions?

Example:
group1: user1, user2
folder: /testfolder
ownership: user1:group1
permission: 750
file1 : /testfolder/file1
ownership: user2:group1
permission: 740

user1 should not be able to delete the file even if he owns the main folder where the file is located.

Appreciate help. Thanks.

[Modris Bremze · Accepted solution]

It might be doable with ACLs. Please see http://docs.hp.com/en/B2355-90950/ch08s04.html

[Horia Chirculescu]

Hello,

How about

chmod g-w file1
chmod u+rw file1
chmod o-rw file1

user1 still have write access on file1?

Horia.

[Dennis Handly]

>user1 should not be able to delete the file even if he owns the main folder where the file is located.

The user can be prevented from modifying the file but nothing can stop him from removing it.
I.e. the user can always change the permissions or ACL to allow write.

The sticky bit would maybe stop a naive user from removing files, for a few seconds.

[Johnson Punniyalingam]

Thanks for all your support