Rewrite an interface similar to user management tools in gnome-system-tools and gnome-control-center, displayed in the control center.
https://askubuntu.com/questions/66718/how-to-manage-users-and-groups
http://ubuntuhandbook.org/index.php/2014/05/install-users-groups-management-tool-ubuntu1404/
http://linuxbsdos.com/2012/04/03/creating-and-managing-user-accounts-in-a-gnome-3-or-ubuntu-desktop/
http://ftp.gnome.org/pub/GNOME/sources/gnome-system-tools/ https://github.com/GNOME/gnome-control-center/
Now there are accountservice DBUS services, which provide many user management related functions, and code can be implemented in DBUS.
meson build -Dprefix=/usr
ninja -C build
sudo ninja -C build install