On Thu, Mar 20, 2025 at 8:24 PM David G. Johnston <
david.g.johns...@gmail.com> wrote:
> It's \pset null for boolean values
>
v1, Ready aside from bike-shedding the name.
David J.
From c897e53577d433c374e51619405a5c2b8bd4151c Mon Sep 17 00:00:00 2001
From: "David G. Johnston" <david.g.johns...@gmail.com>
Date: Wed, 18 Jun 2025 12:20:43 -0700
Subject: [PATCH] Add \pset options for boolean value display
The server's space-expedient choice to use 't' and 'f' to represent
boolean true and false respectively is technically understandable
but visually atrocious. Teach psql to detect these two values
and print whatever it deems is appropriate. For now, in the
interest of backward compatability, that defaults to 't' and 'f'.
However, now the user can impose their own standards by using the
newly introduced display_true and display_false pset settings.
---
doc/src/sgml/ref/psql-ref.sgml | 24 ++++++++++++++++
src/bin/psql/command.c | 45 +++++++++++++++++++++++++++++-
src/fe_utils/print.c | 6 ++++
src/include/fe_utils/print.h | 2 ++
src/test/regress/expected/psql.out | 32 +++++++++++++++++++++
src/test/regress/sql/psql.sql | 16 +++++++++++
6 files changed, 124 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 570ef21d1fc..03d4e429d8a 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -3287,6 +3287,30 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-pset-display_true">
+ <term><literal>display_true</literal></term>
+ <listitem>
+ <para>
+ Sets the string to be printed in place of a true value.
+ The default is to print <literal>t</literal> as that is the value
+ transmitted by the server. For readability,
+ <literal>\pset print_true 'true'</literal> is recommended.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="app-psql-meta-command-pset-display_false">
+ <term><literal>display_false</literal></term>
+ <listitem>
+ <para>
+ Sets the string to be printed in place of a false value.
+ The default is to print <literal>f</literal> as that is the value
+ transmitted by the server. For readability,
+ <literal>\pset print_false 'false'</literal> is recommended.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-pset-null">
<term><literal>null</literal></term>
<listitem>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 83e84a77841..c6afa982a59 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -2688,7 +2688,8 @@ exec_command_pset(PsqlScanState scan_state, bool active_branch)
int i;
static const char *const my_list[] = {
- "border", "columns", "csv_fieldsep", "expanded", "fieldsep",
+ "border", "columns", "csv_fieldsep",
+ "display_true", "display_false", "expanded", "fieldsep",
"fieldsep_zero", "footer", "format", "linestyle", "null",
"numericlocale", "pager", "pager_min_lines",
"recordsep", "recordsep_zero",
@@ -5198,6 +5199,26 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
}
}
+ /* true display */
+ else if (strcmp(param, "display_true") == 0)
+ {
+ if (value)
+ {
+ free(popt->truePrint);
+ popt->truePrint = pg_strdup(value);
+ }
+ }
+
+ /* false display */
+ else if (strcmp(param, "display_false") == 0)
+ {
+ if (value)
+ {
+ free(popt->falsePrint);
+ popt->falsePrint = pg_strdup(value);
+ }
+ }
+
/* field separator for unaligned text */
else if (strcmp(param, "fieldsep") == 0)
{
@@ -5416,6 +5437,20 @@ printPsetInfo(const char *param, printQueryOpt *popt)
popt->nullPrint ? popt->nullPrint : "");
}
+ /* show boolean true display */
+ else if (strcmp(param, "display_true") == 0)
+ {
+ printf(_("Boolean true display is \"%s\".\n"),
+ popt->truePrint ? popt->truePrint : "t");
+ }
+
+ /* show boolean false display */
+ else if (strcmp(param, "display_false") == 0)
+ {
+ printf(_("Boolean false display is \"%s\".\n"),
+ popt->falsePrint ? popt->falsePrint : "f");
+ }
+
/* show locale-aware numeric output */
else if (strcmp(param, "numericlocale") == 0)
{
@@ -5661,6 +5696,14 @@ pset_value_string(const char *param, printQueryOpt *popt)
return pset_quoted_string(popt->nullPrint
? popt->nullPrint
: "");
+ else if (strcmp(param, "display_true") == 0)
+ return pset_quoted_string(popt->truePrint
+ ? popt->truePrint
+ : "t");
+ else if (strcmp(param, "display_false") == 0)
+ return pset_quoted_string(popt->falsePrint
+ ? popt->falsePrint
+ : "f");
else if (strcmp(param, "numericlocale") == 0)
return pstrdup(pset_bool_string(popt->topt.numericLocale));
else if (strcmp(param, "pager") == 0)
diff --git a/src/fe_utils/print.c b/src/fe_utils/print.c
index 4af0f32f2fc..7829460f7d3 100644
--- a/src/fe_utils/print.c
+++ b/src/fe_utils/print.c
@@ -3582,6 +3582,12 @@ printQuery(const PGresult *result, const printQueryOpt *opt,
if (PQgetisnull(result, r, c))
cell = opt->nullPrint ? opt->nullPrint : "";
+ else if (PQftype(result, c) == BOOLOID)
+ {
+ cell = (PQgetvalue(result, r, c)[0] == 't')
+ ? (opt->truePrint ? opt->truePrint : "t")
+ : (opt->falsePrint ? opt->falsePrint : "f");
+ }
else
{
cell = PQgetvalue(result, r, c);
diff --git a/src/include/fe_utils/print.h b/src/include/fe_utils/print.h
index c99c2ee1a31..2378e26acb6 100644
--- a/src/include/fe_utils/print.h
+++ b/src/include/fe_utils/print.h
@@ -184,6 +184,8 @@ typedef struct printQueryOpt
{
printTableOpt topt; /* the options above */
char *nullPrint; /* how to print null entities */
+ char *truePrint; /* how to print boolean true values */
+ char *falsePrint; /* how to print boolean false values */
char *title; /* override title */
char **footers; /* override footer (default is "(xx rows)") */
bool translate_header; /* do gettext on column headers */
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index cf48ae6d0c2..a276d79bf46 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -445,6 +445,8 @@ environment value
border 1
columns 0
csv_fieldsep ','
+display_true 't'
+display_false 'f'
expanded off
fieldsep '|'
fieldsep_zero off
@@ -464,6 +466,36 @@ unicode_border_linestyle single
unicode_column_linestyle single
unicode_header_linestyle single
xheader_width full
+-- test the simple display substitution settings
+prepare q as select null as n, true as t, false as f;
+\pset null '(null)'
+\pset display_true 'true'
+\pset display_false 'false'
+execute q;
+ n | t | f
+--------+------+-------
+ (null) | true | false
+(1 row)
+
+\pset null
+\pset display_true
+\pset display_false
+execute q;
+ n | t | f
+--------+------+-------
+ (null) | true | false
+(1 row)
+
+\pset null ''
+\pset display_true 't'
+\pset display_false 'f'
+execute q;
+ n | t | f
+---+---+---
+ | t | f
+(1 row)
+
+deallocate q;
-- test multi-line headers, wrapping, and newline indicators
-- in aligned, unaligned, and wrapped formats
prepare q as select array_to_string(array_agg(repeat('x',2*n)),E'\n') as "ab
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 1a8a83462f0..c1784a691fe 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -219,6 +219,22 @@ select 'drop table gexec_test', 'select ''2000-01-01''::date as party_over'
-- show all pset options
\pset
+-- test the simple display substitution settings
+prepare q as select null as n, true as t, false as f;
+\pset null '(null)'
+\pset display_true 'true'
+\pset display_false 'false'
+execute q;
+\pset null
+\pset display_true
+\pset display_false
+execute q;
+\pset null ''
+\pset display_true 't'
+\pset display_false 'f'
+execute q;
+deallocate q;
+
-- test multi-line headers, wrapping, and newline indicators
-- in aligned, unaligned, and wrapped formats
prepare q as select array_to_string(array_agg(repeat('x',2*n)),E'\n') as "ab
--
2.34.1
