Here is a diff of changes to the psql source code implementing a simple

'list domains' command '\dD'. This is the interface component of
rbt@zort.ca's domain backend modifications.

Jonathan Eisler

src/bin/psql/command.c

@@ -3,7 +3,7 @@
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/command.c,v 1.67 2002/03/05 00:01:00 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/command.c,v 1.68 2002/03/06 20:39:45 momjian Exp $
  */
 #include "postgres_fe.h"
 #include "command.h"
@@ -380,6 +380,10 @@ exec_command(const char *cmd,
 			case 'u':
 				success = describeUsers(name);
 				break;
+			case 'D':
+				success = listDomains(name);
+				break;
+
 			default:
 				status = CMD_UNKNOWN;
 		}

src/bin/psql/describe.c

@@ -3,7 +3,7 @@
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/describe.c,v 1.43 2002/03/05 02:42:56 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/describe.c,v 1.44 2002/03/06 20:39:45 momjian Exp $
  */
 #include "postgres_fe.h"
 #include "describe.h"
@@ -1036,3 +1036,51 @@ listTables(const char *infotype, const char *name, bool desc)
 	PQclear(res);
 	return true;
 }
+
+/*
+ * \dD [domain]
+ *
+ * Describes domains, possibly based on a simplistic prefix search on the
+ * argument.
+ */
+
+bool
+listDomains(const char *name)
+{
+	char		buf[512 + REGEXP_CUTOFF];
+	PGresult   *res;
+	printQueryOpt myopt = pset.popt;
+
+	snprintf(buf, sizeof(buf),
+		 "SELECT t.typname as \"%s\",\n"
+		 "       format_type( t.typbasetype, t.typmod) as \"%s\",\n"
+		 "       CASE WHEN t.typnotnull AND t.typdefault IS NOT NULL THEN 'not null default '||t.typdefault\n"
+		 "            WHEN t.typnotnull AND t.typdefault IS NULL THEN 'not null'\n"
+		 "            WHEN NOT t.typnotnull AND t.typdefault IS NOT NULL THEN 'default '||t.typdefault\n"
+		 "            ELSE ''\n"
+		 "       END as \"%s\"\n"
+		 "FROM pg_type t\n"
+		 "WHERE t.typtype = 'd'\n",
+		 _("Name"),
+		 _("Type"),
+		 _("Modifier"));
+	if (name)
+	{
+		strcat(buf, "AND t.typname ~ '^");
+		strncat(buf, name, REGEXP_CUTOFF);
+		strcat(buf, "'\n");
+	}
+	strcat(buf, "ORDER BY 1;");
+
+	res = PSQLexec(buf);
+	if (!res)
+		return false;
+
+	myopt.nullPrint = NULL;
+	myopt.title = _("List of database domains");
+
+	printQuery(res, &myopt, pset.queryFout);
+
+	PQclear(res);
+	return true;
+}

src/bin/psql/describe.h

@@ -3,7 +3,7 @@
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/describe.h,v 1.13 2001/11/05 17:46:31 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/describe.h,v 1.14 2002/03/06 20:39:45 momjian Exp $
  */
 #ifndef DESCRIBE_H
 #define DESCRIBE_H
@@ -40,4 +40,7 @@ bool		listAllDbs(bool desc);
 /* \dt, \di, \ds, \dS, etc. */
 bool		listTables(const char *infotype, const char *name, bool desc);
 
+/* \dD */
+bool		listDomains(const char *name);
+
 #endif   /* DESCRIBE_H */

src/bin/psql/help.c

@@ -3,7 +3,7 @@
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/help.c,v 1.44 2002/03/05 06:13:19 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/help.c,v 1.45 2002/03/06 20:39:45 momjian Exp $
  */
 #include "postgres_fe.h"
 #include "help.h"
@@ -202,6 +202,7 @@ slashUsage(void)
 	fprintf(fout, _(" \\d{p|S|l}      list access privileges, system tables, or large objects\n"));
 	fprintf(fout, _(" \\da            list aggregate functions\n"));
 	fprintf(fout, _(" \\dd NAME       show comment for table, type, function, or operator\n"));
+	fprintf(fout, _(" \\dD [NAME]     list domains\n"));
 	fprintf(fout, _(" \\df            list functions\n"));
 	fprintf(fout, _(" \\do            list operators\n"));
 	fprintf(fout, _(" \\dT            list data types\n"));