Re: display hot standby state in psql prompt

On 30/10/2025 11:28, Chao Li wrote:
> How about this?
>
> ```
> [read/write]select * from test_multi order by category, name;
> FATAL: terminating connection due to administrator command
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.
> The connection to the server was lost. Attempting reset: Failed.
> []
> []
> ```
>
> After shutting down the server, I ran a random statement in psql, then the prompt became empty, does it suppose to show “_unknown”?

This behaviour is normal -- at least it is how other options behave. See
%p and the newly committed %S:

postgres=# \set PROMPT1 '[%p] # '
[1376487] # \c
connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file
or directory
Is the server running locally and accepting connections on that
socket?
Previous connection kept
[1376487] # SELECT 1;
FATAL: terminating connection due to administrator command
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
The connection to the server was lost. Attempting reset: Failed.
[] # SELECT 1;
You are currently not connected to a database.
[] #

====

psql (19devel)
Type "help" for help.

postgres=# \set PROMPT1 '[%S] # '
["$user", public] # \c
connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file
or directory
Is the server running locally and accepting connections on that
socket?
Previous connection kept
["$user", public] # SELECT 1;
FATAL: terminating connection due to administrator command
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
The connection to the server was lost. Attempting reset: Failed.
[] # SELECT 1;
You are currently not connected to a database.
[] #

Best, Jim