I would like the Linux filing system to set a specific group when new files and directories are created by different users under a specific directory. I know I can use chmod to change existing files and directories but I want it to happen automatically. Does anyone know how?
The standard user/group/other security model in Unix doesn't support this. The closest you can get are the "sticky" bits to assign ownership and group to newly created files.
However, you tagged this
http://www.vanemery.com/Linux/ACL/linux-acl.html#default has further examples of how to use these tools.
If all you needed to do was make sure new things got created with a specific directory, though, that is much easier:
That has no influence over file mode, just file ownership.