commands: improve help/usage output

Replace --help --help with --long-help.
Some blank lines were needed.
Add 'lvm help all' to print help for all commands.

tools/args.h

@@ -244,6 +244,9 @@ arg(locktype_ARG, '\0', "locktype", locktype_VAL, 0, 0,
 arg(logonly_ARG, '\0', "logonly", 0, 0, 0,
     "Suppress command report and display only log report.\n")
 
+arg(longhelp_ARG, '\0', "longhelp", 0, 0, 0,
+    "Display long help text.\n")
+
 arg(maxrecoveryrate_ARG, '\0', "maxrecoveryrate", sizekb_VAL, 0, 0,
     "Sets the maximum recovery rate for a RAID LV.  The rate value\n"
     "is an amount of data per second for each device in the array.\n"
@@ -920,8 +923,8 @@ arg(force_ARG, 'f', "force", 0, ARG_COUNTABLE, 0,
 /* Not used. */
 arg(full_ARG, 'f', "full", 0, 0, 0, NULL)
 
-arg(help_ARG, 'h', "help", 0, ARG_COUNTABLE, 0,
-    "Display help text. Repeat this option for more information.\n")
+arg(help_ARG, 'h', "help", 0, 0, 0,
+    "Display help text.\n")
 
 arg(cache_ARG, 'H', "cache", 0, 0, 0,
     "Specifies the command is handling a cache LV or cache pool.\n"

tools/command-lines.in

@@ -187,7 +187,7 @@
 # OO_ALL is included in every command automatically.
 #
 OO_ALL: --commandprofile String, --config String, --debug,
---driverloaded Bool, --help, --profile String, --quiet,
+--driverloaded Bool, --help, --longhelp, --profile String, --quiet,
 --verbose, --version, --yes, --test
 
 #

tools/command.c

@@ -1640,7 +1640,7 @@ void print_usage(struct command *cmd)
 
 	printf(" ]");
  done:
-	printf("\n");
+	printf("\n\n");
 	return;
 }
 
@@ -1704,7 +1704,8 @@ void print_usage_common(struct command_name *cname, struct command *cmd)
 		}
 	}
 
-	printf(" ]\n");
+	printf(" ]");
+	printf("\n\n");
 }
 
 #ifdef MAN_PAGE_GENERATOR

tools/lvmcmdline.c

@@ -1384,7 +1384,7 @@ static struct command *_find_command(struct cmd_context *cmd, const char *path,
 			continue;
 
 		/* For help and version just return the first entry with matching name. */
-		if (arg_is_set(cmd, help_ARG) || arg_is_set(cmd, help2_ARG) || arg_is_set(cmd, version_ARG))
+		if (arg_is_set(cmd, help_ARG) || arg_is_set(cmd, help2_ARG) || arg_is_set(cmd, longhelp_ARG) || arg_is_set(cmd, version_ARG))
 			return &commands[i];
 
 		match_required = 0;    /* required parameters that match */
@@ -1661,35 +1661,8 @@ static void _short_usage(const char *name)
 	log_error("Run `%s --help' for more information.", name);
 }
 
-static int _usage(const char *name, int help_count)
+static void _usage_notes(void)
 {
-	struct command_name *cname = find_command_name(name);
-	struct command *cmd;
-	int i;
-
-	if (!cname) {
-		log_print("%s: no such command.", name);
-		return 0;
-	}
-
-	log_print("%s - %s\n", name, cname->desc);
-
-	for (i = 0; i < COMMAND_COUNT; i++) {
-		if (strcmp(_cmdline.commands[i].name, name))
-			continue;
-
-		if ((_cmdline.commands[i].cmd_flags & CMD_FLAG_SECONDARY_SYNTAX) && (help_count < 3))
-			continue;
-
-		print_usage(&_cmdline.commands[i]);
-		cmd = &_cmdline.commands[i];
-		printf("\n");
-	}
-
-	/* Common options are printed once for all variants of a command name. */
-	print_usage_common(cname, cmd);
-
-	if (help_count > 1) {
 	/*
 	 * Excluding commonly understood syntax style like the meanings of:
 	 * [ ] for optional, ... for repeatable, | for one of the following,
@@ -1715,15 +1688,56 @@ static int _usage(const char *name, int help_count)
 	log_print("  which represents other possible input units: bBsSkKmMgGtTpPeE.");
 	log_print(". Output units can be specified with the --units option, for which");
 	log_print("  lower/upper case letters refer to base 2/10 values.");
-		log_print(". Use --help --help --help to print secondary command syntax");
 	log_print("  formats that are recognized, e.g. for compatibility.");
 	log_print(". See man pages for short option equivalents of long option names,");
 	log_print("  and for more detailed descriptions of variable parameters.");
+	log_print(" ");
 }
 
+static int _usage(const char *name, int longhelp)
+{
+	struct command_name *cname = find_command_name(name);
+	struct command *cmd;
+	int i;
+
+	if (!cname) {
+		log_print("%s: no such command.", name);
+		return 0;
+	}
+
+	log_print("%s - %s\n", name, cname->desc);
+
+	for (i = 0; i < COMMAND_COUNT; i++) {
+		if (strcmp(_cmdline.commands[i].name, name))
+			continue;
+
+		if ((_cmdline.commands[i].cmd_flags & CMD_FLAG_SECONDARY_SYNTAX) && !longhelp)
+			continue;
+
+		print_usage(&_cmdline.commands[i]);
+		cmd = &_cmdline.commands[i];
+	}
+
+	/* Common options are printed once for all variants of a command name. */
+	print_usage_common(cname, cmd);
+
+	if (longhelp)
+		_usage_notes();
+
 	return 1;
 }
 
+static void _usage_all(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_COMMAND_NAMES; i++) {
+		if (!command_names[i].name)
+			break;
+		_usage(command_names[i].name, 0);
+	}
+}
+
 /*
  * Sets up the arguments to pass to getopt_long().
  *
@@ -2158,11 +2172,10 @@ static int _get_settings(struct cmd_context *cmd)
 
 static int _process_common_commands(struct cmd_context *cmd)
 {
-	if (arg_is_set(cmd, help_ARG) || arg_is_set(cmd, help2_ARG)) {
-		_usage(cmd->name, arg_count(cmd, help_ARG));
-
-		if (arg_count(cmd, help_ARG) < 2)
-			log_print("(Use --help --help for usage notes.)");
+	if (arg_is_set(cmd, help_ARG) ||
+	    arg_is_set(cmd, longhelp_ARG) ||
+	    arg_is_set(cmd, help2_ARG)) {
+		_usage(cmd->name, arg_is_set(cmd, longhelp_ARG));
 		return ECMD_PROCESSED;
 	}
 
@@ -2195,6 +2208,8 @@ int help(struct cmd_context *cmd __attribute__((unused)), int argc, char **argv)
 
 	if (!argc)
 		_display_help();
+	else if (argc == 1 && !strcmp(argv[0], "all"))
+		_usage_all();
 	else {
 		int i;
 		for (i = 0; i < argc; i++)