Use ls -l to see which permissions are present in the current files.
Use whoimi to see what is the current user.
Use groups to see to which security groups belongs the current user.
Use id to see information about the current user.
How to know the group the user belongs to?
Change to the user you want to know more info about and write the command id
How to change a user's group?
Change to the user you want to add to a group and write the command newgrp
Change file owner and group
Change file owner and group
Change the user and group of one or more elements (files and directories). The -R option makes it recursive (useful for changing the permissions of a directory and all or some of its files).
Syntax
chown [OPTION] [OWNER]:[GROUP] ELEMENT
USER - If only the user is specified, the specified user will become the owner of the given files. The group ownership is not changed.
USER: - When the username is followed by a colon :, and the group name is not given, the user will become the owner of the files, and the files group ownership is changed to the user’s login group.
USER:GROUP - If both the user and the group are specified (with no space between them), the user ownership of the files is changed to the given user and the group ownership is changed to the given group.
:GROUP - If the User is omitted and the group is prefixed with a colon :, only the group ownership of the files is changed to the given group.
: If only a colon : is given, without specifying the user and the group, no change is made.