Add --no-instructions parameter to initdb

Specifying this parameter removes the informational messages about how
to start the server. This is intended for use by wrappers in different
packaging systems, where those instructions would most likely be wrong
anyway, but the other output from initdb would still be useful (and thus
just redirecting everything to /dev/null would be bad).

Author: Magnus Hagander
Reviewed-By: Peter Eisentraut
Discusion: https://postgr.es/m/CABUevEzo4t5bmTXF0_B9WzmuWpVbMpkNZZiGvzV8NZa-=fPqeQ@mail.gmail.com

doc/src/sgml/ref/initdb.sgml

@@ -275,6 +275,19 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--no-instructions</option></term>
+      <listitem>
+       <para>
+        By default, <command>initdb</command> will write instructions for how
+        to start the cluster at the end of its output. This option causes
+        those instructions to be left out. This is primarily intended for use
+        by tools that wrap <command>initdb</command> in platform specific
+        behavior, where those instructions are likely to be incorrect.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--pwfile=<replaceable>filename</replaceable></option></term>
       <listitem>

src/bin/initdb/initdb.c

@@ -139,6 +139,7 @@ static const char *authmethodhost = NULL;
 static const char *authmethodlocal = NULL;
 static bool debug = false;
 static bool noclean = false;
+static bool noinstructions = false;
 static bool do_sync = true;
 static bool sync_only = false;
 static bool show_setting = false;
@@ -2294,6 +2295,7 @@ usage(const char *progname)
 	printf(_("  -L DIRECTORY              where to find the input files\n"));
 	printf(_("  -n, --no-clean            do not clean up after errors\n"));
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
+	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
 	printf(_("  -S, --sync-only           only sync data directory\n"));
 	printf(_("\nOther options:\n"));
@@ -2955,6 +2957,7 @@ main(int argc, char *argv[])
 		{"no-clean", no_argument, NULL, 'n'},
 		{"nosync", no_argument, NULL, 'N'}, /* for backwards compatibility */
 		{"no-sync", no_argument, NULL, 'N'},
+		{"no-instructions", no_argument, NULL, 13},
 		{"sync-only", no_argument, NULL, 'S'},
 		{"waldir", required_argument, NULL, 'X'},
 		{"wal-segsize", required_argument, NULL, 12},
@@ -3095,6 +3098,9 @@ main(int argc, char *argv[])
 			case 12:
 				str_wal_segment_size_mb = pg_strdup(optarg);
 				break;
+			case 13:
+				noinstructions = true;
+				break;
 			case 'g':
 				SetDataDirectoryCreatePerm(PG_DIR_MODE_GROUP);
 				break;
@@ -3245,34 +3251,40 @@ main(int argc, char *argv[])
 						  "--auth-local and --auth-host, the next time you run initdb.\n"));
 	}
 
-	/*
-	 * Build up a shell command to tell the user how to start the server
-	 */
-	start_db_cmd = createPQExpBuffer();
+	if (!noinstructions)
+	{
+		/*
+		 * Build up a shell command to tell the user how to start the server
+		 */
+		start_db_cmd = createPQExpBuffer();
+
+		/* Get directory specification used to start initdb ... */
+		strlcpy(pg_ctl_path, argv[0], sizeof(pg_ctl_path));
+		canonicalize_path(pg_ctl_path);
+		get_parent_directory(pg_ctl_path);
+		/* ... and tag on pg_ctl instead */
+		join_path_components(pg_ctl_path, pg_ctl_path, "pg_ctl");
 
-	/* Get directory specification used to start initdb ... */
-	strlcpy(pg_ctl_path, argv[0], sizeof(pg_ctl_path));
-	canonicalize_path(pg_ctl_path);
-	get_parent_directory(pg_ctl_path);
-	/* ... and tag on pg_ctl instead */
-	join_path_components(pg_ctl_path, pg_ctl_path, "pg_ctl");
+		/* path to pg_ctl, properly quoted */
+		appendShellString(start_db_cmd, pg_ctl_path);
 
-	/* path to pg_ctl, properly quoted */
-	appendShellString(start_db_cmd, pg_ctl_path);
+		/* add -D switch, with properly quoted data directory */
+		appendPQExpBufferStr(start_db_cmd, " -D ");
+		appendShellString(start_db_cmd, pgdata_native);
 
-	/* add -D switch, with properly quoted data directory */
-	appendPQExpBufferStr(start_db_cmd, " -D ");
-	appendShellString(start_db_cmd, pgdata_native);
+		/* add suggested -l switch and "start" command */
+		/* translator: This is a placeholder in a shell command. */
+		appendPQExpBuffer(start_db_cmd, " -l %s start", _("logfile"));
 
-	/* add suggested -l switch and "start" command */
-	/* translator: This is a placeholder in a shell command. */
-	appendPQExpBuffer(start_db_cmd, " -l %s start", _("logfile"));
+		printf(_("\nSuccess. You can now start the database server using:\n\n"
+				 "    %s\n\n"),
+			   start_db_cmd->data);
 
-	printf(_("\nSuccess. You can now start the database server using:\n\n"
-			 "    %s\n\n"),
-		   start_db_cmd->data);
+		destroyPQExpBuffer(start_db_cmd);
+
+		printf(_("\nSuccess.\n"));
+	}
 
-	destroyPQExpBuffer(start_db_cmd);
 
 	success = true;
 	return 0;