From the psql interface, run the \du command:
在psql界面中,运行\du命令:

This will give you the list of all users in the system, plus their role attributes and the list of role groups they are member of.
这将为您提供系统中所有用户的列表,以及他们的角色属性和他们所属的角色组的列表。
翻译自: https://flaviocopes.com/postgres-how-to-list-all-users/