cmd: add support for showing placeholder commands/opts/args in command usage strings

cmd/command.c

@@ -305,6 +305,21 @@ b_status b_command_usage_add_arg(
 	return B_SUCCESS;
 }
 
+b_status b_command_usage_add_command(b_command_usage *usage, unsigned int cmd_id)
+{
+	struct b_command_usage_command *u_cmd = malloc(sizeof *u_cmd);
+	if (!u_cmd) {
+		return B_ERR_NO_MEMORY;
+	}
+
+	memset(u_cmd, 0x0, sizeof *u_cmd);
+
+	u_cmd->cmd_id = cmd_id;
+
+	b_queue_push_back(&usage->u_cmd, &u_cmd->cmd_entry);
+	return B_SUCCESS;
+}
+
 static void prepend_command_name(struct b_command *cmd, b_string *out)
 {
 	int nr_names = 0;
@@ -362,7 +377,33 @@ static void get_usage_string(
 {
 	get_qualified_command_name(cmd, out);
 
+	struct b_string *cmd_name = b_string_create();
+
 	b_queue_iterator it;
+	b_queue_foreach (&it, &usage->u_cmd) {
+		struct b_command_usage_command *subcmd = b_unbox(
+			struct b_command_usage_command, it.entry, cmd_entry);
+
+		if (!subcmd) {
+			break;
+		}
+
+		b_string_clear(cmd_name);
+		b_string_append_cstr(out, " ");
+
+		if (subcmd->cmd_id == B_COMMAND_INVALID_ID) {
+			b_string_append_cstr(out, "[COMMAND]");
+		} else {
+			struct b_command *subcmd_info
+				= get_command(&command_list, subcmd->cmd_id);
+			prepend_command_name(subcmd_info, cmd_name);
+
+			b_string_append_s(out, cmd_name);
+		}
+	}
+
+	b_string_release(cmd_name);
+
 	b_queue_foreach (&it, &usage->u_opt) {
 		struct b_command_usage_opt *opt = b_unbox(
 			struct b_command_usage_opt, it.entry, opt_entry);
@@ -372,7 +413,13 @@ static void get_usage_string(
 		}
 
 		b_string_append_cstr(out, " ");
-		z__b_get_option_usage_string(opt->opt, CMD_STR_DIRECT_USAGE, out);
+
+		if (opt->opt == (struct b_command_option *)B_COMMAND_INVALID_ID) {
+			b_string_append_cstr(out, "[OPTIONS]");
+		} else {
+			z__b_get_option_usage_string(
+				opt->opt, CMD_STR_DIRECT_USAGE, out);
+		}
 	}
 
 	b_queue_foreach (&it, &usage->u_arg) {
@@ -384,7 +431,12 @@ static void get_usage_string(
 		}
 
 		b_string_append_cstr(out, " ");
-		z__b_get_arg_usage_string(arg->arg, false, out);
+
+		if (arg->arg == (struct b_command_arg *)B_COMMAND_INVALID_ID) {
+			b_string_append_cstr(out, "[ARGS]");
+		} else {
+			z__b_get_arg_usage_string(arg->arg, false, out);
+		}
 	}
 }
 

cmd/command.h

@@ -51,10 +51,16 @@ struct b_command_usage_arg {
 	struct b_command_arg *arg;
 };
 
+struct b_command_usage_command {
+	struct b_queue_entry cmd_entry;
+	unsigned int cmd_id;
+};
+
 struct b_command_usage {
 	b_command_usage_flags u_flags;
 	struct b_queue_entry u_entry;
 
+	struct b_queue u_cmd;
 	struct b_queue u_opt;
 	struct b_queue u_arg;
 };

cmd/include/blue/cmd.h

@@ -94,12 +94,26 @@
 	this_usage = z__b_unique_name();                                       \
 	if (this_usage)
 
+#define B_COMMAND_USAGE_COMMAND(cmd_id)                                        \
+	b_command_usage_add_command(this_usage, cmd_id)
+
+#define B_COMMAND_USAGE_COMMAND_PLACEHOLDER()                                  \
+	b_command_usage_add_command(this_usage, B_COMMAND_INVALID_ID)
+
 #define B_COMMAND_USAGE_OPT(opt_id)                                            \
 	b_command_usage_add_option(this_usage, opt_##opt_id)
 
+#define B_COMMAND_USAGE_OPT_PLACEHOLDER()                                      \
+	b_command_usage_add_option(                                            \
+		this_usage, (struct b_command_option *)B_COMMAND_INVALID_ID)
+
 #define B_COMMAND_USAGE_ARG(opt_id)                                            \
 	b_command_usage_add_arg(this_usage, arg_##opt_id)
 
+#define B_COMMAND_USAGE_ARG_PLACEHOLDER()                                      \
+	b_command_usage_add_arg(                                               \
+		this_usage, (struct b_command_arg *)B_COMMAND_INVALID_ID)
+
 #define B_COMMAND_OPTION_HELP ((unsigned int)0xF0000001)
 #define B_COMMAND_INVALID_ID  ((unsigned int)0xFFFFFFFF)
 
@@ -192,6 +206,8 @@ extern b_status b_command_arg_set_allowed_values(
 extern b_status b_command_usage_add_option(
 	b_command_usage *usage, b_command_option *opt);
 extern b_status b_command_usage_add_arg(b_command_usage *usage, b_command_arg *opt);
+extern b_status b_command_usage_add_command(
+	b_command_usage *usage, unsigned int cmd_id);
 
 extern b_status b_arglist_get_string(
 	const b_arglist *args, unsigned int opt_id, unsigned int arg_id,