On 27/01/2026 14:51, Fujii Masao wrote:
> It looks like the short description for %i is missing from the header comment
> at the top of get_prompt(). Could you add that?
>
>
> In the patch, nothing is shown when connected to PostgreSQL 13 or older
> (i.e., versions that do not report in_hot_standby). Would it be better to
> show "?", similar to what %S does?
It seems I reverted too much from the previous patch :)
Description added again.
>
>
> + else
> + buf[0] = '\0';
> + }
> + else
> + buf[0] = '\0';
>
> The second "else + buf[0] = '\0'" does not seem necessary.
Here I was just following the style of other options, like %x
case 'x':
if (!pset.db)
buf[0] = '?';
Removed (let me know if I misunderstood your point here)
>
> + <listitem>
> + <para>
> + Indicates whether the server is in hot standby mode.
>
> The indentation style for "<para>" and its contents seems to differ from
> the surrounding prompt option descriptions. For consistency, it might be
> better to match the existing style used nearby.
Indentation fixed.
>
>
> + The value is shown as <literal>standby</literal> if the
> server reports
> + <literal>in_hot_standby</literal> as <literal>on</literal>,
>
> Would it be better to replace "<literal>in_hot_standby</literal>" with
> "<xref linkend="guc-in-hot-standby"/>"?
>
Yes, it's indeed much better. Replaced <literal>in_hot_standby</literal>
with <xref linkend="guc-in-hot-standby"/>.
> As with %S, it would be helpful to explicitly document what is shown when
> connected to PostgreSQL 13 or older. For example, something like:
>
> -----------------
> Indicates whether the connected server is running in hot standby mode.
> The value is shown as <literal>standby</literal> if the server is
> currently in hot standby and reports <xref
> linkend="guc-in-hot-standby"/> as <literal>on</literal>, and
> <literal>primary</literal> otherwise. This is useful when connecting
> to multiple servers to quickly determine the role of each connection.
> A value of <literal>?</literal> is shown when connected to a server
> running <productname>PostgreSQL</productname> 13 or older.
> -----------------
Added as you suggested.
Thanks for the quick review. Much appreciated!
Best, JimFrom b73bab3819514da14df93c8a14c51d7840d9335c Mon Sep 17 00:00:00 2001
From: Jim Jones <[email protected]>
Date: Tue, 27 Jan 2026 15:27:13 +0100
Subject: [PATCH v9] Add %i prompt escape to indicate hot standby status
This patch introduces a new prompt escape %i for psql, which shows
whether the connected server is operating in hot standby mode. It
expands to standby if the server reports in_hot_standby = on, and
primary otherwise.
This is useful for distinguishing standby servers from primary ones
at a glance, especially when working with multiple connections in
replicated environments where libpq's multi-host connection strings
are used.
Author: Jim Jones <[email protected]>
Reviewed-by: Fujii Masao <[email protected]>
Reviewed-by: Greg Sabino Mullane <[email protected]>
Reviewed-by: Srinath Reddy Sadipiralla <[email protected]>
Reviewed-by: Nathan Bossart <[email protected]>
Reviewed-by: Chao Li <[email protected]>
Reviewed-by: Andreas Karlsson <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/[email protected]
---
doc/src/sgml/ref/psql-ref.sgml | 16 ++++++++++++++++
src/bin/psql/prompt.c | 18 +++++++++++++++++-
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index e464e3b13d..e27bba9c88 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -5075,6 +5075,22 @@ testdb=> <userinput>INSERT INTO my_table VALUES (:'content');</userinput>
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-prompting-i">
+ <term><literal>%i</literal></term>
+ <listitem>
+ <para>
+ Indicates whether the server is in hot standby mode.
+ The value is shown as <literal>standby</literal> if the server reports
+ <xref linkend="guc-in-hot-standby"/> as <literal>on</literal>,
+ and <literal>primary</literal> otherwise.
+ This can be useful when connecting to multiple hosts to quickly identify
+ if the connected server is currently in recovery mode.
+ A value of <literal>?</literal> is shown when connected to a server
+ running <productname>PostgreSQL</productname> 13 or older.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-prompting-x">
<term><literal>%x</literal></term>
<listitem>
diff --git a/src/bin/psql/prompt.c b/src/bin/psql/prompt.c
index 44eae59641..7aae217fb2 100644
--- a/src/bin/psql/prompt.c
+++ b/src/bin/psql/prompt.c
@@ -44,6 +44,8 @@
* or a ! if session is not connected to a database;
* in prompt2 -, *, ', or ";
* in prompt3 nothing
+ * %i - "standby" or "primary" depending on the server's in_hot_standby
+ * status, or "?" if unavailable (empty if unknown)
* %x - transaction status: empty, *, !, ? (unknown or no connection)
* %l - The line number inside the current statement, starting from 1.
* %? - the error code of the last query (not yet implemented)
@@ -258,7 +260,21 @@ get_prompt(promptStatus_t status, ConditionalStack cstack)
break;
}
break;
-
+ case 'i':
+ if (pset.db)
+ {
+ const char *hs = PQparameterStatus(pset.db, "in_hot_standby");
+ if (hs)
+ {
+ if (strcmp(hs, "on") == 0)
+ strlcpy(buf, "standby", sizeof(buf));
+ else
+ strlcpy(buf, "primary", sizeof(buf));
+ }
+ else
+ buf[0] = '?';
+ }
+ break;
case 'x':
if (!pset.db)
buf[0] = '?';
--
2.43.0
