Show a PostgreSQL setting in psql shell

When you for example set shared_buffers=1GB in your postgresql.conf file and then want to verify this setting in a query, or the psql shell, it gets a bit confusing.

postgres=# select name,setting,unit from pg_settings where name='shared_buffers';
      name      | setting | unit
----------------+---------+------
 shared_buffers | 131072  | 8kB
(1 row)

There are two ways to view the correct value.

postgres=# select name, current_setting(name) from pg_settings where name='shared_buffers';
      name      | current_setting
----------------+-----------------
 shared_buffers | 1GB
(1 row)

postgres=# SHOW shared_buffers;
 shared_buffers
----------------
 1GB
(1 row)