L~$ id -nG victor0000
victor0000 mail dialout cdrom plugdev lpadmin admin sambashare vboxusers libvirtd smmta smmsp davfs2
L~$ id -nG mo
mo
L~$ sudo usermod mail,dialout,cdrom,plugdev,lpadmin,admin,sambashare,vboxusers,libvirtd,smmta,smmsp,davfs2,mo mo
[sudo] password for victor0000:
usermod: не заданы параметры
L~$ sudo usermod -G mail,dialout,cdrom,plugdev,lpadmin,admin,sambashare,vboxusers,libvirtd,smmta,smmsp,davfs2,mo mo
L~$ id -nG mo
mo mail dialout cdrom plugdev lpadmin admin sambashare vboxusers libvirtd smmta smmsp davfs2
L~$ sudo usermod -G mo mo
L~$ id -nG mo
mo
L~$