AddUserToGroups adds a user to a list of specified groups on a host using `usermod`.

CheckSudoers tests a suders file using `visudo`.

GroupAdd creates a group on a host using `groupadd` optionally specifying the GID to create the group with.

UserAdd creates a user on a host using `useradd`.

UserDel deletes a user on a host using `userdel`.

man GROUPADD(8), exit codes section.

man USERADD(8), exit codes section.