From: Tom Lane <tgl@sss.pgh.pa.us>
To: Soumya S Murali <soumyamurali.work@gmail.com>
cc: Oleg Tselebrovskiy <o.tselebrovskiy@postgrespro.ru>,
        pgsql-hackers@postgresql.org
Subject: Re: 001_password.pl fails with --without-readline
In-reply-to: <1718312.1768603611@sss.pgh.pa.us>
References: <db6fdb35a8665ad3c18be01181d44b31@postgrespro.ru>
 <c19ac5e530c27b69ded0c8efcc581772@postgrespro.ru>
 <CAMtXxw9Vk+7_F1-Q6gYhEBCARZUbbpH7gjVcgxg0WVeSN_mX8A@mail.gmail.com>
 <1768548191.602324347@fmail2.qdit>
 <CAMtXxw9PVPyiHY6y4CxS4L92wDqpOp6DsLpC4sAsqT5WO963xA@mail.gmail.com>
 <1718312.1768603611@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Fri, 16 Jan 2026 17:46:51 -0500"
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="----- =_aaaaaaaaaa0"
Content-ID: <1892274.1768609173.0@sss.pgh.pa.us>
Date: Fri, 16 Jan 2026 19:19:38 -0500
Message-ID: <1892298.1768609178@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/1892298.1768609178%40sss.pgh.pa.us>
Precedence: bulk

------- =_aaaaaaaaaa0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <1892274.1768609173.1@sss.pgh.pa.us>

I wrote:
> There are various ways that could be done, but what I propose in the
> attached v3 is to break the banner into two psql variables, like so:
> 	\set part1 something
> 	\set part2 else
> 	\echo :part1 :part2
> Then, if we match for "something else", there is no possibility
> whatsoever that that will match echoed commands, only the real
> output of the \echo.

On second thought, that's far more complicated than necessary.
It should be sufficient to insert quote marks in the echo commands.

			regards, tom lane


------- =_aaaaaaaaaa0
Content-Type: text/x-diff;
	name="v4-0001-background-psql-without-readline.patch";
	charset="us-ascii"
Content-ID: <1892274.1768609173.2@sss.pgh.pa.us>
Content-Description: v4-0001-background-psql-without-readline.patch
Content-Transfer-Encoding: quoted-printable

diff --git a/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm b/src/test/pe=
rl/PostgreSQL/Test/BackgroundPsql.pm
index 5bd41a278dd..eb2a252a7d7 100644
--- a/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm
+++ b/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm
@@ -100,7 +100,7 @@ sub new
 	  "Forbidden caller of constructor: package: $package, file: $file:$line=
"
 	  unless $package->isa('PostgreSQL::Test::Cluster');
 =

-	$psql->{timeout} =3D IPC::Run::timeout(
+	$psql->{timeout} =3D IPC::Run::timer(
 		defined($timeout)
 		? $timeout
 		: $PostgreSQL::Test::Utils::timeout_default);
@@ -155,11 +155,11 @@ sub wait_connect
 	#
 	# See query() for details about why/how the banner is used.
 	my $banner =3D "background_psql: ready";
-	my $banner_match =3D qr/(^|\n)$banner\r?\n/;
-	$self->{stdin} .=3D "\\echo $banner\n\\warn $banner\n";
+	my $banner_match =3D qr/$banner\r?\n/;
+	$self->{stdin} .=3D "\\echo '$banner'\n\\warn '$banner'\n";
 	$self->{run}->pump()
 	  until ($self->{stdout} =3D~ /$banner_match/
-		  && $self->{stderr} =3D~ /$banner\r?\n/)
+		  && $self->{stderr} =3D~ /$banner_match/)
 	  || $self->{timeout}->is_expired;
 =

 	note "connect output:\n",
@@ -264,22 +264,17 @@ sub query
 	# stderr (or vice versa), even if psql printed them in the opposite
 	# order. We therefore wait on both.
 	#
-	# We need to match for the newline, because we try to remove it below, a=
nd
-	# it's possible to consume just the input *without* the newline. In
-	# interactive psql we emit \r\n, so we need to allow for that. Also need
-	# to be careful that we don't e.g. match the echoed \echo command, rathe=
r
-	# than its output.
+	# In interactive psql we emit \r\n, so we need to allow for that.
+	# Also, include quotes around the banner string in the \echo and \warn
+	# commands, not because the string needs quoting but so that $banner_mat=
ch
+	# can't match readline's echoing of these commands.
 	my $banner =3D "background_psql: QUERY_SEPARATOR $query_cnt:";
-	my $banner_match =3D qr/(^|\n)$banner\r?\n/;
-	$self->{stdin} .=3D "$query\n;\n\\echo $banner\n\\warn $banner\n";
-	pump_until(
-		$self->{run}, $self->{timeout},
-		\$self->{stdout}, qr/$banner_match/);
-	pump_until(
-		$self->{run}, $self->{timeout},
-		\$self->{stderr}, qr/$banner_match/);
-
-	die "psql query timed out" if $self->{timeout}->is_expired;
+	my $banner_match =3D qr/$banner\r?\n/;
+	$self->{stdin} .=3D "$query\n;\n\\echo '$banner'\n\\warn '$banner'\n";
+	$self->{run}->pump()
+	  until ($self->{stdout} =3D~ /$banner_match/
+		  && $self->{stderr} =3D~ /$banner_match/)
+	  || $self->{timeout}->is_expired;
 =

 	note "results query $query_cnt:\n",
 	  explain {
@@ -287,9 +282,12 @@ sub query
 		stderr =3D> $self->{stderr},
 	  } unless !$params{verbose};
 =

-	# Remove banner from stdout and stderr, our caller doesn't care.  The
-	# first newline is optional, as there would not be one if consuming an
-	# empty query result.
+	die "psql query timed out" if $self->{timeout}->is_expired;
+
+	# Remove banner from stdout and stderr, our caller doesn't want it.
+	# Also remove the query output's trailing newline, if present (there
+	# would not be one if consuming an empty query result).
+	$banner_match =3D qr/\r?\n?$banner\r?\n/;
 	$output =3D $self->{stdout};
 	$output =3D~ s/$banner_match//;
 	$self->{stderr} =3D~ s/$banner_match//;

------- =_aaaaaaaaaa0
Content-Type: text/x-diff; name="v4-0002-030-pager-fix.patch";
	charset="us-ascii"
Content-ID: <1892274.1768609173.3@sss.pgh.pa.us>
Content-Description: v4-0002-030-pager-fix.patch

diff --git a/src/bin/psql/t/030_pager.pl b/src/bin/psql/t/030_pager.pl
index cf81fb1603c..a35f2b26293 100644
--- a/src/bin/psql/t/030_pager.pl
+++ b/src/bin/psql/t/030_pager.pl
@@ -40,6 +40,36 @@ my $node = PostgreSQL::Test::Cluster->new('main');
 $node->init;
 $node->start;
 
+# create a view we'll use below
+$node->safe_psql(
+	'postgres', 'create view public.view_030_pager as select
+1 as a,
+2 as b,
+3 as c,
+4 as d,
+5 as e,
+6 as f,
+7 as g,
+8 as h,
+9 as i,
+10 as j,
+11 as k,
+12 as l,
+13 as m,
+14 as n,
+15 as o,
+16 as p,
+17 as q,
+18 as r,
+19 as s,
+20 as t,
+21 as u,
+22 as v,
+23 as w,
+24 as x,
+25 as y,
+26 as z');
+
 # fire up an interactive psql session
 my $h = $node->interactive_psql('postgres');
 
@@ -77,25 +107,28 @@ sub do_command
 #
 # Note that interactive_psql starts psql with --no-align --tuples-only,
 # and that the output string will include psql's prompts and command echo.
+# So we have to test for patterns that can't match the command itself,
+# and we can't assume the match will extend across a whole line (there
+# might be a prompt ahead of it in the output).
 
 do_command(
 	"SELECT 'test' AS t FROM generate_series(1,23);\n",
-	qr/^test\r?$/m,
+	qr/test\r?$/m,
 	"execute SELECT query that needs no pagination");
 
 do_command(
 	"SELECT 'test' AS t FROM generate_series(1,24);\n",
-	qr/^ *24\r?$/m,
+	qr/24\r?$/m,
 	"execute SELECT query that needs pagination");
 
 do_command(
 	"\\pset expanded\nSELECT generate_series(1,20) as g;\n",
-	qr/^ *39\r?$/m,
+	qr/39\r?$/m,
 	"execute SELECT query that needs pagination in expanded mode");
 
 do_command(
-	"\\pset tuples_only off\n\\d+ information_schema.referential_constraints\n",
-	qr/^ *\d+\r?$/m,
+	"\\pset tuples_only off\n\\d+ public.view_030_pager\n",
+	qr/55\r?$/m,
 	"execute command with footer that needs pagination");
 
 # send psql an explicit \q to shut it down, else pty won't close properly

------- =_aaaaaaaaaa0--