pg_createsubscriber: Improve error messages.

Consistently, an option name is used in the error messages where
applicable. Also, change the code to use pg_fatal() instead of a
combination of pg_log_error() and exit().

Author: vignesh C <vignesh21@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CALDaNm0HxF1RH27LP7VisLzNsSJbssy8a64M5p6UduDaBq6-ag@mail.gmail.com

src/bin/pg_basebackup/pg_createsubscriber.c

@@ -2124,10 +2124,7 @@ main(int argc, char **argv)
 					num_dbs++;
 				}
 				else
-				{
-					pg_log_error("database \"%s\" specified more than once", optarg);
-					exit(1);
-				}
+					pg_fatal("database \"%s\" specified more than once for -d/--database", optarg);
 				break;
 			case 'D':
 				subscriber_dir = pg_strdup(optarg);
@@ -2146,7 +2143,7 @@ main(int argc, char **argv)
 				if (!simple_string_list_member(&opt.objecttypes_to_remove, optarg))
 					simple_string_list_append(&opt.objecttypes_to_remove, optarg);
 				else
-					pg_fatal("object type \"%s\" is specified more than once for --remove", optarg);
+					pg_fatal("object type \"%s\" is specified more than once for -R/--remove", optarg);
 				break;
 			case 's':
 				opt.socket_dir = pg_strdup(optarg);
@@ -2174,10 +2171,7 @@ main(int argc, char **argv)
 					num_pubs++;
 				}
 				else
-				{
-					pg_log_error("publication \"%s\" specified more than once", optarg);
-					exit(1);
-				}
+					pg_fatal("publication \"%s\" specified more than once for --publication", optarg);
 				break;
 			case 3:
 				if (!simple_string_list_member(&opt.replslot_names, optarg))
@@ -2186,10 +2180,7 @@ main(int argc, char **argv)
 					num_replslots++;
 				}
 				else
-				{
-					pg_log_error("replication slot \"%s\" specified more than once", optarg);
-					exit(1);
-				}
+					pg_fatal("replication slot \"%s\" specified more than once for --replication-slot", optarg);
 				break;
 			case 4:
 				if (!simple_string_list_member(&opt.sub_names, optarg))
@@ -2198,10 +2189,7 @@ main(int argc, char **argv)
 					num_subs++;
 				}
 				else
-				{
-					pg_log_error("subscription \"%s\" specified more than once", optarg);
-					exit(1);
-				}
+					pg_fatal("subscription \"%s\" specified more than once for --subscription", optarg);
 				break;
 			default:
 				/* getopt_long already emitted a complaint */
@@ -2226,7 +2214,7 @@ main(int argc, char **argv)
 
 		if (bad_switch)
 		{
-			pg_log_error("%s cannot be used with --all", bad_switch);
+			pg_log_error("%s cannot be used with -a/--all", bad_switch);
 			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
 			exit(1);
 		}
@@ -2352,7 +2340,7 @@ main(int argc, char **argv)
 			dbinfos.objecttypes_to_remove |= OBJECTTYPE_PUBLICATIONS;
 		else
 		{
-			pg_log_error("invalid object type \"%s\" specified for --remove", cell->val);
+			pg_log_error("invalid object type \"%s\" specified for -R/--remove", cell->val);
 			pg_log_error_hint("The valid option is: \"publications\"");
 			exit(1);
 		}

src/bin/pg_basebackup/t/040_pg_createsubscriber.pl

@@ -399,7 +399,7 @@ command_fails_like(
 		'--database' => $db1,
 		'--all',
 	],
-	qr/--database cannot be used with --all/,
+	qr/--database cannot be used with -a\/--all/,
 	'fail if --database is used with --all');
 
 # run pg_createsubscriber with '--publication' and '--all' and verify
@@ -416,7 +416,7 @@ command_fails_like(
 		'--all',
 		'--publication' => 'pub1',
 	],
-	qr/--publication cannot be used with --all/,
+	qr/--publication cannot be used with -a\/--all/,
 	'fail if --publication is used with --all');
 
 # run pg_createsubscriber with '--all' option