I want every user to have full permissions over a single directory(and all the contents). Is this possible, and how? Thanks.
You can get what you want to with adding users in particular group and then applying full permission to that group.
Then following command-line information can help you:
The guest session user could then not access the contents of
Looks like users created in GUI or at installation are not added to Users group automatically. I assumed this to be true.
you would have to
This would need you to add users to the group manually thus making this answer by TuKsn just as easy.
You can create a group for all the user which should have access to this folder.
Create a new group:
Add a user to the group
Change user and group of the directory
Change the permissions of the directory
Edit: As Shutupsquare suggest you can use the group users which already exists. To add all human users to the group you can use:
based on: http://askubuntu.com/a/329689/265974