Keep same file owner for newly created files

Question

This question is regarding samba file access.

I have created a folder A, and under folder A created two folders B and C. And also created three users A, B and C.

User A has access to all three folders but User B has only access to folder B and User C has only access to folder C.

Permission of B & C folders are:

drwxrwxr-x 3 a b 4096 May 10 16:22 b
drwxrwxr-x 3 a c 4096 May 10 16:43 c

Problem:

When user B creates any new file under folder B, it's permission becomes

drwxr-x--- 2 b b 4096 May 10 16:21 New Folder

whereas I want it to keep the owner, group and permission same as folder B for any newly created files.

Solution

Folder b and c are owned by user b and c. A file created by a user will belong to that user.

You can use the user permission for b and c, and the group permissions for a. If you set the SGID bit (g+s) on a folder, created files will get the group permission of that folder.

mkdir a
chown a:a a
chmod g+s a

mkdir b
chown b:a b

mkdir c
chown c:a c

(assuming all users are in a group of the same name.)

Comments

[Admin]

"User A has access to all three folders" shall mean "write access"? Why do you want to change the owner, or is this about access rights only?

[Admin]

ohh i am sorry i missed a main part. folder B and folder C is created under folder A.

[Admin]

@Kevin main question was wrong...I have edited it now.

[Admin]

and I also think SGID and SUID will do the job... but haven't tried yet.

[PeeJay]

so i don't need to do sticky bit in folder b and c?

[slm]

@user1723636, just so you understand the SGID bit and the "sticky bit" are 2 completely different things. See man chmod.

[slm]

@aust - Is make use of ACL's instead.