let's say we have dir1 with mode 755 root root and I want user1 to be able to write to the directory, but I don't want to add him to the root group or change the user or group ownership of the directory. Is there something along the lines of
chmod user1+w for only granting additional access to a single user without disturbing ownership or adding the user to another group? ACLs perhaps?
CentOS 6.4 EXT4