How to Set SUID so files owned by owner of directory ?

[Sammy_2]

I have user (samu11) put files in
/home/cognos directory. The files are owned by samu11. How do I make so any files put in /home/cognos are always owned by cognos user.

Thanks

[James R. Ferguson · Accepted solution]

Hi Sammy:

The best you can do is set the 'setgid' bit on the "/home/cognos" directory. Then, when any user who has permission to write into that directory does so, the files added will have a _group_ ownership of the "/home/cognos" directory.

Regards!

...JRF...

[Sammy_2]

Thanks, JRF. The SGID worked.
but SUID on a directory does not.
But is it possible to change the owner of the file in a directory to have the same owner as the directory itself.
We got different users put out file in a directory but just want one owner of all files in there.

[Patrick Wallek]

The only thing I can think of is to have a cron job run periodically that changes the ownership of the files in that directory.

[Pete Randall]

The only thing I can think of is to write a script that will be run by cron at whatever interval you deem necessary. Said script would look at the ownership of the directory, then chown -R the directory, thus ensuring that all files are owned by the directory owner.


Pete

[James R. Ferguson]

Hi (again) Sammy:

> The SGID worked. but SUID on a directory does not.

That's correct. The idea of a 'setuid' bit is that when set for an executable, the executable runs with an effective UID of the executable file's owner. The 'passwd' command is one classic example. That command runs with an effective UID of 'root'.

This said, of course, if a SETUID executable were to create a file, then the owner of the file would be that of the effective UID.

You do NOT want to travel this road except in very, very special cases. As Patrick and Pete said, setup a 'cron'task to 'chown' what you need.

Regards!

...JRF...

[Sammy_2]

Thanks Pat and Pete. I will use cron.
And of course , kudos to JRF for explaining the SUID concept.