Extend psql's \lo_list/\dl to be able to print large objects' ACLs.

The ACL is printed when you add + to the command, similarly to
various other psql backslash commands.

Along the way, move the code for this into describe.c,
where it is a better fit (and can share some code).

Pavel Luzanov, reviewed by Georgios Kokolatos

Discussion: https://postgr.es/m/6d722115-6297-bc53-bb7f-5f150e765299@postgrespro.ru

Author: tglsfdc

doc/src/sgml/ddl.sgml

@@ -2146,7 +2146,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
       <entry><literal>LARGE OBJECT</literal></entry>
       <entry><literal>rw</literal></entry>
       <entry>none</entry>
-      <entry></entry>
+      <entry><literal>\dl+</literal></entry>
      </row>
      <row>
       <entry><literal>SCHEMA</literal></entry>

doc/src/sgml/ref/psql-ref.sgml

@@ -1681,11 +1681,14 @@ testdb=>
 
 
       <varlistentry>
-        <term><literal>\dl</literal></term>
+        <term><literal>\dl[+]</literal></term>
         <listitem>
         <para>
         This is an alias for <command>\lo_list</command>, which shows a
         list of large objects.
+        If <literal>+</literal> is appended to the command name,
+        each large object is listed with its associated permissions,
+        if any.
         </para>
         </listitem>
       </varlistentry>
@@ -2610,12 +2613,15 @@ lo_import 152801
       </varlistentry>
 
       <varlistentry>
-        <term><literal>\lo_list</literal></term>
+        <term><literal>\lo_list[+]</literal></term>
         <listitem>
         <para>
         Shows a list of all <productname>PostgreSQL</productname>
         large objects currently stored in the database,
         along with any comments provided for them.
+        If <literal>+</literal> is appended to the command name,
+        each large object is listed with its associated permissions,
+        if any.
         </para>
         </listitem>
       </varlistentry>

src/bin/psql/command.c

@@ -811,7 +811,7 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
 				success = describeRoles(pattern, show_verbose, show_system);
 				break;
 			case 'l':
-				success = do_lo_list();
+				success = listLargeObjects(show_verbose);
 				break;
 			case 'L':
 				success = listLanguages(pattern, show_verbose, show_system);
@@ -1963,7 +1963,9 @@ exec_command_lo(PsqlScanState scan_state, bool active_branch, const char *cmd)
 		}
 
 		else if (strcmp(cmd + 3, "list") == 0)
-			success = do_lo_list();
+			success = listLargeObjects(false);
+		else if (strcmp(cmd + 3, "list+") == 0)
+			success = listLargeObjects(true);
 
 		else if (strcmp(cmd + 3, "unlink") == 0)
 		{

src/bin/psql/describe.c

@@ -6463,3 +6463,49 @@ listOpFamilyFunctions(const char *access_method_pattern,
 	PQclear(res);
 	return true;
 }
+
+/*
+ * \dl or \lo_list
+ * Lists large objects
+ */
+bool
+listLargeObjects(bool verbose)
+{
+	PQExpBufferData buf;
+	PGresult   *res;
+	printQueryOpt myopt = pset.popt;
+
+	initPQExpBuffer(&buf);
+
+	printfPQExpBuffer(&buf,
+					  "SELECT oid as \"%s\",\n"
+					  "  pg_catalog.pg_get_userbyid(lomowner) as \"%s\",\n  ",
+					  gettext_noop("ID"),
+					  gettext_noop("Owner"));
+
+	if (verbose)
+	{
+		printACLColumn(&buf, "lomacl");
+		appendPQExpBufferStr(&buf, ",\n  ");
+	}
+
+	appendPQExpBuffer(&buf,
+					  "pg_catalog.obj_description(oid, 'pg_largeobject') as \"%s\"\n"
+					  "FROM pg_catalog.pg_largeobject_metadata\n"
+					  "ORDER BY oid",
+					  gettext_noop("Description"));
+
+	res = PSQLexec(buf.data);
+	termPQExpBuffer(&buf);
+	if (!res)
+		return false;
+
+	myopt.nullPrint = NULL;
+	myopt.title = _("Large objects");
+	myopt.translate_header = true;
+
+	printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+
+	PQclear(res);
+	return true;
+}

src/bin/psql/describe.h

@@ -139,5 +139,7 @@ extern bool listOpFamilyOperators(const char *accessMethod_pattern,
 extern bool listOpFamilyFunctions(const char *access_method_pattern,
 								  const char *family_pattern, bool verbose);
 
+/* \dl or \lo_list */
+extern bool listLargeObjects(bool verbose);
 
 #endif							/* DESCRIBE_H */

src/bin/psql/help.c

@@ -248,7 +248,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\dFt[+] [PATTERN]      list text search templates\n"));
 	fprintf(output, _("  \\dg[S+] [PATTERN]      list roles\n"));
 	fprintf(output, _("  \\di[S+] [PATTERN]      list indexes\n"));
-	fprintf(output, _("  \\dl                    list large objects, same as \\lo_list\n"));
+	fprintf(output, _("  \\dl[+]                 list large objects, same as \\lo_list\n"));
 	fprintf(output, _("  \\dL[S+] [PATTERN]      list procedural languages\n"));
 	fprintf(output, _("  \\dm[S+] [PATTERN]      list materialized views\n"));
 	fprintf(output, _("  \\dn[S+] [PATTERN]      list schemas\n"));
@@ -325,7 +325,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("Large Objects\n"));
 	fprintf(output, _("  \\lo_export LOBOID FILE\n"
 					  "  \\lo_import FILE [COMMENT]\n"
-					  "  \\lo_list\n"
+					  "  \\lo_list[+]\n"
 					  "  \\lo_unlink LOBOID      large object operations\n"));
 
 	ClosePager(output);

src/bin/psql/large_obj.c

@@ -262,42 +262,3 @@ do_lo_unlink(const char *loid_arg)
 
 	return true;
 }
-
-
-
-/*
- * do_lo_list()
- *
- * Show all large objects in database with comments
- */
-bool
-do_lo_list(void)
-{
-	PGresult   *res;
-	char		buf[1024];
-	printQueryOpt myopt = pset.popt;
-
-	snprintf(buf, sizeof(buf),
-			 "SELECT oid as \"%s\",\n"
-			 "  pg_catalog.pg_get_userbyid(lomowner) as \"%s\",\n"
-			 "  pg_catalog.obj_description(oid, 'pg_largeobject') as \"%s\"\n"
-			 "  FROM pg_catalog.pg_largeobject_metadata "
-			 "  ORDER BY oid",
-			 gettext_noop("ID"),
-			 gettext_noop("Owner"),
-			 gettext_noop("Description"));
-
-	res = PSQLexec(buf);
-	if (!res)
-		return false;
-
-	myopt.topt.tuples_only = false;
-	myopt.nullPrint = NULL;
-	myopt.title = _("Large objects");
-	myopt.translate_header = true;
-
-	printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
-
-	PQclear(res);
-	return true;
-}

src/bin/psql/large_obj.h

@@ -11,6 +11,5 @@
 bool		do_lo_export(const char *loid_arg, const char *filename_arg);
 bool		do_lo_import(const char *filename_arg, const char *comment_arg);
 bool		do_lo_unlink(const char *loid_arg);
-bool		do_lo_list(void);
 
 #endif							/* LARGE_OBJ_H */

src/test/regress/expected/largeobject.out

@@ -6,31 +6,46 @@
 \getenv abs_builddir PG_ABS_BUILDDIR
 -- ensure consistent test output regardless of the default bytea format
 SET bytea_output TO escape;
+-- Test ALTER LARGE OBJECT OWNER, GRANT, COMMENT
+CREATE ROLE regress_lo_user;
+SELECT lo_create(42);
+ lo_create 
+-----------
+        42
+(1 row)
+
+ALTER LARGE OBJECT 42 OWNER TO regress_lo_user;
+GRANT SELECT ON LARGE OBJECT 42 TO public;
+COMMENT ON LARGE OBJECT 42 IS 'the ultimate answer';
+-- Test psql's \lo_list et al (we assume no other LOs exist yet)
+\lo_list
+               Large objects
+ ID |      Owner      |     Description     
+----+-----------------+---------------------
+ 42 | regress_lo_user | the ultimate answer
+(1 row)
+
+\lo_list+
+                                  Large objects
+ ID |      Owner      |         Access privileges          |     Description     
+----+-----------------+------------------------------------+---------------------
+ 42 | regress_lo_user | regress_lo_user=rw/regress_lo_user+| the ultimate answer
+    |                 | =r/regress_lo_user                 | 
+(1 row)
+
+\lo_unlink 42
+\dl
+      Large objects
+ ID | Owner | Description 
+----+-------+-------------
+(0 rows)
+
 -- Load a file
 CREATE TABLE lotest_stash_values (loid oid, fd integer);
 -- lo_creat(mode integer) returns oid
 -- The mode arg to lo_creat is unused, some vestigal holdover from ancient times
 -- returns the large object id
 INSERT INTO lotest_stash_values (loid) SELECT lo_creat(42);
--- Test ALTER LARGE OBJECT
-CREATE ROLE regress_lo_user;
-DO $$
-  BEGIN
-    EXECUTE 'ALTER LARGE OBJECT ' || (select loid from lotest_stash_values)
-		|| ' OWNER TO regress_lo_user';
-  END
-$$;
-SELECT
-	rol.rolname
-FROM
-	lotest_stash_values s
-	JOIN pg_largeobject_metadata lo ON s.loid = lo.oid
-	JOIN pg_authid rol ON lo.lomowner = rol.oid;
-     rolname     
------------------
- regress_lo_user
-(1 row)
-
 -- NOTE: large objects require transactions
 BEGIN;
 -- lo_open(lobjId oid, mode integer) returns integer

src/test/regress/expected/largeobject_1.out

@@ -6,31 +6,46 @@
 \getenv abs_builddir PG_ABS_BUILDDIR
 -- ensure consistent test output regardless of the default bytea format
 SET bytea_output TO escape;
+-- Test ALTER LARGE OBJECT OWNER, GRANT, COMMENT
+CREATE ROLE regress_lo_user;
+SELECT lo_create(42);
+ lo_create 
+-----------
+        42
+(1 row)
+
+ALTER LARGE OBJECT 42 OWNER TO regress_lo_user;
+GRANT SELECT ON LARGE OBJECT 42 TO public;
+COMMENT ON LARGE OBJECT 42 IS 'the ultimate answer';
+-- Test psql's \lo_list et al (we assume no other LOs exist yet)
+\lo_list
+               Large objects
+ ID |      Owner      |     Description     
+----+-----------------+---------------------
+ 42 | regress_lo_user | the ultimate answer
+(1 row)
+
+\lo_list+
+                                  Large objects
+ ID |      Owner      |         Access privileges          |     Description     
+----+-----------------+------------------------------------+---------------------
+ 42 | regress_lo_user | regress_lo_user=rw/regress_lo_user+| the ultimate answer
+    |                 | =r/regress_lo_user                 | 
+(1 row)
+
+\lo_unlink 42
+\dl
+      Large objects
+ ID | Owner | Description 
+----+-------+-------------
+(0 rows)
+
 -- Load a file
 CREATE TABLE lotest_stash_values (loid oid, fd integer);
 -- lo_creat(mode integer) returns oid
 -- The mode arg to lo_creat is unused, some vestigal holdover from ancient times
 -- returns the large object id
 INSERT INTO lotest_stash_values (loid) SELECT lo_creat(42);
--- Test ALTER LARGE OBJECT
-CREATE ROLE regress_lo_user;
-DO $$
-  BEGIN
-    EXECUTE 'ALTER LARGE OBJECT ' || (select loid from lotest_stash_values)
-		|| ' OWNER TO regress_lo_user';
-  END
-$$;
-SELECT
-	rol.rolname
-FROM
-	lotest_stash_values s
-	JOIN pg_largeobject_metadata lo ON s.loid = lo.oid
-	JOIN pg_authid rol ON lo.lomowner = rol.oid;
-     rolname     
------------------
- regress_lo_user
-(1 row)
-
 -- NOTE: large objects require transactions
 BEGIN;
 -- lo_open(lobjId oid, mode integer) returns integer