The post usermod Command: Manage Linux Users, Groups, UID, Shell and More first appeared on Tecmint: Linux Howtos, Tutorials & Guides .Most admins learn usermod -aG in their first week and never read much beyond it. But drop the -a onceThe post usermod Command: Manage Linux Users, Groups, UID, Shell and More first appeared on Tecmint: Linux Howtos, Tutorials & Guides.