Validate command argument types (string or command list) and give more

useful error messages.

arguments.c

@@ -124,10 +124,11 @@ args_create(void)
 /* Parse arguments into a new argument set. */
 struct args *
 args_parse(const struct args_parse *parse, struct args_value *values,
-    u_int count)
+    u_int count, char **cause)
 {
 	struct args		*args;
 	u_int			 i;
+	enum args_parse_type	 type;
 	struct args_value	*value, *new;
 	u_char			 flag, argument;
 	const char		*found, *string, *s;
@@ -153,11 +154,13 @@ args_parse(const struct args_parse *parse, struct args_value *values,
 			if (flag == '\0')
 				break;
 			if (!isalnum(flag)) {
+				xasprintf(cause, "invalid flag -%c", flag);
 				args_free(args);
 				return (NULL);
 			}
 			found = strchr(parse->template, flag);
 			if (found == NULL) {
+				xasprintf(cause, "unknown flag -%c", flag);
 				args_free(args);
 				return (NULL);
 			}
@@ -167,12 +170,22 @@ args_parse(const struct args_parse *parse, struct args_value *values,
 				args_set(args, flag, NULL);
 				continue;
 			}
-			new = xcalloc(1, sizeof *value);
+			new = xcalloc(1, sizeof *new);
 			if (*string != '\0') {
 				new->type = ARGS_STRING;
 				new->string = xstrdup(string);
 			} else {
 				if (i == count) {
+					xasprintf(cause,
+					    "-%c expects an argument",
+					    flag);
+					args_free(args);
+					return (NULL);
+				}
+				if (values[i].type != ARGS_STRING) {
+					xasprintf(cause,
+					    "-%c argument must be a string",
+					    flag);
 					args_free(args);
 					return (NULL);
 				}
@@ -192,14 +205,60 @@ args_parse(const struct args_parse *parse, struct args_value *values,
 			s = args_value_as_string(value);
 			log_debug("%s: %u = %s", __func__, i, s);
 
+			if (parse->cb != NULL) {
+				type = parse->cb(args, args->count, cause);
+				if (type == ARGS_PARSE_INVALID) {
+					args_free(args);
+					return (NULL);
+				}
+			} else
+				type = ARGS_PARSE_STRING;
+
 			args->values = xrecallocarray(args->values,
 			    args->count, args->count + 1, sizeof *args->values);
-			args_copy_value(&args->values[args->count++], value);
+			new = &args->values[args->count++];
+
+			switch (type) {
+			case ARGS_PARSE_INVALID:
+				fatalx("unexpected argument type");
+			case ARGS_PARSE_STRING:
+				if (value->type != ARGS_STRING) {
+					xasprintf(cause,
+					    "argument %u must be \"string\"",
+					    args->count);
+					args_free(args);
+					return (NULL);
+				}
+				args_copy_value(new, value);
+				break;
+			case ARGS_PARSE_COMMANDS_OR_STRING:
+				args_copy_value(new, value);
+				break;
+			case ARGS_PARSE_COMMANDS:
+				if (value->type != ARGS_COMMANDS) {
+					xasprintf(cause,
+					    "argument %u must be { commands }",
+					    args->count);
+					args_free(args);
+					return (NULL);
+				}
+				args_copy_value(new, value);
+				break;
+			}
 		}
 	}
 
-	if ((parse->lower != -1 && args->count < (u_int)parse->lower) ||
+	if (parse->lower != -1 && args->count < (u_int)parse->lower) {
-	    (parse->upper != -1 && args->count > (u_int)parse->upper)) {
+		xasprintf(cause,
+		    "too few arguments (need at least %u)",
+		    parse->lower);
+		args_free(args);
+		return (NULL);
+	}
+	if (parse->upper != -1 && args->count > (u_int)parse->upper) {
+		xasprintf(cause,
+		    "too many arguments (need at most %u)",
+		    parse->upper);
 		args_free(args);
 		return (NULL);
 	}
@@ -254,15 +313,25 @@ args_free(struct args *args)
 void
 args_vector(struct args *args, int *argc, char ***argv)
 {
-	struct args_value	*value;
+	char	*s;
 	u_int	 i;
 
 	*argc = 0;
 	*argv = NULL;
 
 	for (i = 0; i < args->count; i++) {
-		value = &args->values[i];
+		switch (args->values[i].type) {
-		cmd_append_argv(argc, argv, args_value_as_string(value));
+		case ARGS_NONE:
+			break;
+		case ARGS_STRING:
+			cmd_append_argv(argc, argv, args->values[i].string);
+			break;
+		case ARGS_COMMANDS:
+			s = cmd_list_print(args->values[i].cmdlist, 0);
+			cmd_append_argv(argc, argv, s);
+			free(s);
+			break;
+		}
 	}
 }
 

cmd-bind-key.c

@@ -27,13 +27,16 @@
  * Bind a key to a command.
  */
 
-static enum cmd_retval	cmd_bind_key_exec(struct cmd *, struct cmdq_item *);
+static enum args_parse_type	cmd_bind_key_args_parse(struct args *, u_int,
+				    char **);
+static enum cmd_retval		cmd_bind_key_exec(struct cmd *,
+				    struct cmdq_item *);
 
 const struct cmd_entry cmd_bind_key_entry = {
 	.name = "bind-key",
 	.alias = "bind",
 
-	.args = { "nrN:T:", 1, -1, NULL },
+	.args = { "nrN:T:", 1, -1, cmd_bind_key_args_parse },
 	.usage = "[-nr] [-T key-table] [-N note] key "
 	         "[command [arguments]]",
 
@@ -41,6 +44,15 @@ const struct cmd_entry cmd_bind_key_entry = {
 	.exec = cmd_bind_key_exec
 };
 
+static enum args_parse_type
+cmd_bind_key_args_parse(__unused struct args *args, u_int idx,
+    __unused char **cause)
+{
+	if (idx == 1)
+		return (ARGS_PARSE_COMMANDS_OR_STRING);
+	return (ARGS_PARSE_STRING);
+}
+
 static enum cmd_retval
 cmd_bind_key_exec(struct cmd *self, struct cmdq_item *item)
 {

cmd-command-prompt.c

@@ -29,6 +29,8 @@
  * Prompt for command in client.
  */
 
+static enum args_parse_type	cmd_command_prompt_args_parse(struct args *,
+				    u_int, char **);
 static enum cmd_retval		cmd_command_prompt_exec(struct cmd *,
 				    struct cmdq_item *);
 
@@ -40,7 +42,7 @@ const struct cmd_entry cmd_command_prompt_entry = {
 	.name = "command-prompt",
 	.alias = NULL,
 
-	.args = { "1bFkiI:Np:t:T:", 0, 1, NULL },
+	.args = { "1bFkiI:Np:t:T:", 0, 1, cmd_command_prompt_args_parse },
 	.usage = "[-1bFkiN] [-I inputs] [-p prompts] " CMD_TARGET_CLIENT_USAGE
 		 " [-T type] [template]",
 
@@ -68,6 +70,13 @@ struct cmd_command_prompt_cdata {
 	char				**argv;
 };
 
+static enum args_parse_type
+cmd_command_prompt_args_parse(__unused struct args *args, __unused u_int idx,
+    __unused char **cause)
+{
+	return (ARGS_PARSE_COMMANDS_OR_STRING);
+}
+
 static enum cmd_retval
 cmd_command_prompt_exec(struct cmd *self, struct cmdq_item *item)
 {

cmd-confirm-before.c

@@ -28,6 +28,8 @@
  * Asks for confirmation before executing a command.
  */
 
+static enum args_parse_type	cmd_confirm_before_args_parse(struct args *,
+				    u_int, char **);
 static enum cmd_retval		cmd_confirm_before_exec(struct cmd *,
 				    struct cmdq_item *);
 
@@ -39,7 +41,7 @@ const struct cmd_entry cmd_confirm_before_entry = {
 	.name = "confirm-before",
 	.alias = "confirm",
 
-	.args = { "bp:t:", 1, 1, NULL },
+	.args = { "bp:t:", 1, 1, cmd_confirm_before_args_parse },
 	.usage = "[-b] [-p prompt] " CMD_TARGET_CLIENT_USAGE " command",
 
 	.flags = CMD_CLIENT_TFLAG,
@@ -51,6 +53,13 @@ struct cmd_confirm_before_data {
 	struct cmd_list		*cmdlist;
 };
 
+static enum args_parse_type
+cmd_confirm_before_args_parse(__unused struct args *args, __unused u_int idx,
+    __unused char **cause)
+{
+	return (ARGS_PARSE_COMMANDS_OR_STRING);
+}
+
 static enum cmd_retval
 cmd_confirm_before_exec(struct cmd *self, struct cmdq_item *item)
 {

cmd-display-menu.c

@@ -28,6 +28,8 @@
  * Display a menu on a client.
  */
 
+static enum args_parse_type	cmd_display_menu_args_parse(struct args *,
+				    u_int, char **);
 static enum cmd_retval		cmd_display_menu_exec(struct cmd *,
 				    struct cmdq_item *);
 static enum cmd_retval		cmd_display_popup_exec(struct cmd *,
@@ -37,7 +39,7 @@ const struct cmd_entry cmd_display_menu_entry = {
 	.name = "display-menu",
 	.alias = "menu",
 
-	.args = { "c:t:OT:x:y:", 1, -1, NULL },
+	.args = { "c:t:OT:x:y:", 1, -1, cmd_display_menu_args_parse },
 	.usage = "[-O] [-c target-client] " CMD_TARGET_PANE_USAGE " [-T title] "
 		 "[-x position] [-y position] name key command ...",
 
@@ -54,7 +56,7 @@ const struct cmd_entry cmd_display_popup_entry = {
 	.args = { "BCc:d:Eh:t:w:x:y:", 0, -1, NULL },
 	.usage = "[-BCE] [-c target-client] [-d start-directory] [-h height] "
 		 CMD_TARGET_PANE_USAGE " [-w width] "
-	         "[-x position] [-y position] [command]",
+		 "[-x position] [-y position] [shell-command]",
 
 	.target = { 't', CMD_FIND_PANE, 0 },
 
@@ -62,6 +64,30 @@ const struct cmd_entry cmd_display_popup_entry = {
 	.exec = cmd_display_popup_exec
 };
 
+static enum args_parse_type
+cmd_display_menu_args_parse(struct args *args, u_int idx, __unused char **cause)
+{
+	u_int			 i = 0;
+	enum args_parse_type	 type = ARGS_PARSE_STRING;
+
+	for (;;) {
+		type = ARGS_PARSE_STRING;
+		if (i == idx)
+			break;
+		if (*args_string(args, i++) == '\0')
+			continue;
+
+		type = ARGS_PARSE_STRING;
+		if (i++ == idx)
+			break;
+
+		type = ARGS_PARSE_COMMANDS_OR_STRING;
+		if (i++ == idx)
+			break;
+	}
+	return (type);
+}
+
 static int
 cmd_display_menu_get_position(struct client *tc, struct cmdq_item *item,
     struct args *args, u_int *px, u_int *py, u_int w, u_int h)

cmd-display-panes.c

@@ -27,6 +27,8 @@
  * Display panes on a client.
  */
 
+static enum args_parse_type	cmd_display_panes_args_parse(struct args *,
+				    u_int, char **);
 static enum cmd_retval		cmd_display_panes_exec(struct cmd *,
 				    struct cmdq_item *);
 
@@ -34,7 +36,7 @@ const struct cmd_entry cmd_display_panes_entry = {
 	.name = "display-panes",
 	.alias = "displayp",
 
-	.args = { "bd:Nt:", 0, 1, NULL },
+	.args = { "bd:Nt:", 0, 1, cmd_display_panes_args_parse },
 	.usage = "[-bN] [-d duration] " CMD_TARGET_CLIENT_USAGE " [template]",
 
 	.flags = CMD_AFTERHOOK|CMD_CLIENT_TFLAG,
@@ -46,6 +48,13 @@ struct cmd_display_panes_data {
 	struct args_command_state	*state;
 };
 
+static enum args_parse_type
+cmd_display_panes_args_parse(__unused struct args *args, __unused u_int idx,
+    __unused char **cause)
+{
+	return (ARGS_PARSE_COMMANDS_OR_STRING);
+}
+
 static void
 cmd_display_panes_draw_pane(struct screen_redraw_ctx *ctx,
     struct window_pane *wp)

cmd-if-shell.c

@@ -29,7 +29,10 @@
  * Executes a tmux command if a shell command returns true or false.
  */
 
-static enum cmd_retval	cmd_if_shell_exec(struct cmd *, struct cmdq_item *);
+static enum args_parse_type	cmd_if_shell_args_parse(struct args *, u_int,
+				    char **);
+static enum cmd_retval		cmd_if_shell_exec(struct cmd *,
+				    struct cmdq_item *);
 
 static void	cmd_if_shell_callback(struct job *);
 static void	cmd_if_shell_free(void *);
@@ -38,7 +41,7 @@ const struct cmd_entry cmd_if_shell_entry = {
 	.name = "if-shell",
 	.alias = "if",
 
-	.args = { "bFt:", 2, 3, NULL },
+	.args = { "bFt:", 2, 3, cmd_if_shell_args_parse },
 	.usage = "[-bF] " CMD_TARGET_PANE_USAGE " shell-command command "
 		 "[command]",
 
@@ -56,6 +59,15 @@ struct cmd_if_shell_data {
 	struct cmdq_item	*item;
 };
 
+static enum args_parse_type
+cmd_if_shell_args_parse(__unused struct args *args, u_int idx,
+    __unused char **cause)
+{
+	if (idx == 1 || idx == 2)
+		return (ARGS_PARSE_COMMANDS_OR_STRING);
+	return (ARGS_PARSE_STRING);
+}
+
 static enum cmd_retval
 cmd_if_shell_exec(struct cmd *self, struct cmdq_item *item)
 {

cmd-run-shell.c

@@ -30,7 +30,10 @@
  * Runs a command without a window.
  */
 
-static enum cmd_retval	cmd_run_shell_exec(struct cmd *, struct cmdq_item *);
+static enum args_parse_type	cmd_run_shell_args_parse(struct args *, u_int,
+				    char **);
+static enum cmd_retval		cmd_run_shell_exec(struct cmd *,
+				    struct cmdq_item *);
 
 static void	cmd_run_shell_timer(int, short, void *);
 static void	cmd_run_shell_callback(struct job *);
@@ -41,7 +44,7 @@ const struct cmd_entry cmd_run_shell_entry = {
 	.name = "run-shell",
 	.alias = "run",
 
-	.args = { "bd:Ct:", 0, 1, NULL },
+	.args = { "bd:Ct:", 0, 1, cmd_run_shell_args_parse },
 	.usage = "[-bC] [-d delay] " CMD_TARGET_PANE_USAGE " [shell-command]",
 
 	.target = { 't', CMD_FIND_PANE, CMD_FIND_CANFAIL },
@@ -62,6 +65,15 @@ struct cmd_run_shell_data {
 	int			 flags;
 };
 
+static enum args_parse_type
+cmd_run_shell_args_parse(struct args *args, __unused u_int idx,
+    __unused char **cause)
+{
+	if (args_has(args, 'C'))
+		return (ARGS_PARSE_COMMANDS_OR_STRING);
+	return (ARGS_PARSE_STRING);
+}
+
 static void
 cmd_run_shell_print(struct job *job, const char *msg)
 {

cmd-set-option.c

@@ -27,13 +27,16 @@
  * Set an option.
  */
 
-static enum cmd_retval	cmd_set_option_exec(struct cmd *, struct cmdq_item *);
+static enum args_parse_type	cmd_set_option_args_parse(struct args *,
+				    u_int, char **);
+static enum cmd_retval		cmd_set_option_exec(struct cmd *,
+				    struct cmdq_item *);
 
 const struct cmd_entry cmd_set_option_entry = {
 	.name = "set-option",
 	.alias = "set",
 
-	.args = { "aFgopqst:uUw", 1, 2, NULL },
+	.args = { "aFgopqst:uUw", 1, 2, cmd_set_option_args_parse },
 	.usage = "[-aFgopqsuUw] " CMD_TARGET_PANE_USAGE " option [value]",
 
 	.target = { 't', CMD_FIND_PANE, CMD_FIND_CANFAIL },
@@ -46,7 +49,7 @@ const struct cmd_entry cmd_set_window_option_entry = {
 	.name = "set-window-option",
 	.alias = "setw",
 
-	.args = { "aFgoqt:u", 1, 2, NULL },
+	.args = { "aFgoqt:u", 1, 2, cmd_set_option_args_parse },
 	.usage = "[-aFgoqu] " CMD_TARGET_WINDOW_USAGE " option [value]",
 
 	.target = { 't', CMD_FIND_WINDOW, CMD_FIND_CANFAIL },
@@ -59,7 +62,7 @@ const struct cmd_entry cmd_set_hook_entry = {
 	.name = "set-hook",
 	.alias = NULL,
 
-	.args = { "agpRt:uw", 1, 2, NULL },
+	.args = { "agpRt:uw", 1, 2, cmd_set_option_args_parse },
 	.usage = "[-agpRuw] " CMD_TARGET_PANE_USAGE " hook [command]",
 
 	.target = { 't', CMD_FIND_PANE, CMD_FIND_CANFAIL },
@@ -68,6 +71,15 @@ const struct cmd_entry cmd_set_hook_entry = {
 	.exec = cmd_set_option_exec
 };
 
+static enum args_parse_type
+cmd_set_option_args_parse(__unused struct args *args, u_int idx,
+    __unused char **cause)
+{
+	if (idx == 1)
+		return (ARGS_PARSE_COMMANDS_OR_STRING);
+	return (ARGS_PARSE_STRING);
+}
+
 static enum cmd_retval
 cmd_set_option_exec(struct cmd *self, struct cmdq_item *item)
 {

cmd.c

@@ -502,6 +502,7 @@ cmd_parse(struct args_value *values, u_int count, const char *file, u_int line,
 	const struct cmd_entry	*entry;
 	struct cmd		*cmd;
 	struct args		*args;
+	char			*error;
 
 	if (count == 0 || values[0].type != ARGS_STRING) {
 		xasprintf(cause, "no command");
@@ -511,11 +512,16 @@ cmd_parse(struct args_value *values, u_int count, const char *file, u_int line,
 	if (entry == NULL)
 		return (NULL);
 
-	args = args_parse(&entry->args, values, count);
+	args = args_parse(&entry->args, values, count, &error);
-	if (args == NULL) {
+	if (args == NULL && error == NULL) {
 		xasprintf(cause, "usage: %s %s", entry->name, entry->usage);
 		return (NULL);
 	}
+	if (args == NULL) {
+		xasprintf(cause, "command %s: %s", entry->name, error);
+		free(error);
+		return (NULL);
+	}
 
 	cmd = xcalloc(1, sizeof *cmd);
 	cmd->entry = entry;

key-bindings.c

@@ -634,8 +634,10 @@ key_bindings_init(void)
 
 	for (i = 0; i < nitems(defaults); i++) {
 		pr = cmd_parse_from_string(defaults[i], NULL);
-		if (pr->status != CMD_PARSE_SUCCESS)
+		if (pr->status != CMD_PARSE_SUCCESS) {
+			log_debug("%s", pr->error);
 			fatalx("bad default key: %s", defaults[i]);
+		}
 		cmdq_append(NULL, cmdq_get_command(pr->cmdlist, NULL));
 		cmd_list_free(pr->cmdlist);
 	}

tmux.h

@@ -1378,8 +1378,16 @@ struct args_value {
 struct args_entry;
 RB_HEAD(args_tree, args_entry);
 
+/* Arguments parsing type. */
+enum args_parse_type {
+	ARGS_PARSE_INVALID,
+	ARGS_PARSE_STRING,
+	ARGS_PARSE_COMMANDS_OR_STRING,
+	ARGS_PARSE_COMMANDS
+};
+
 /* Arguments parsing state. */
-typedef enum args_type (*args_parse_cb)(struct args *, u_int);
+typedef enum args_parse_type (*args_parse_cb)(struct args *, u_int, char **);
 struct args_parse {
 	const char	*template;
 	int		 lower;
@@ -2201,7 +2209,7 @@ int		tty_keys_next(struct tty *);
 void		 args_set(struct args *, u_char, struct args_value *);
 struct args 	*args_create(void);
 struct args	*args_parse(const struct args_parse *, struct args_value *,
-    		     u_int);
+		     u_int, char **);
 void		 args_vector(struct args *, int *, char ***);
 void		 args_free_value(struct args_value *);
 void		 args_free(struct args *);