diff --git a/arguments.c b/arguments.c
index 5c53b3cf5..7852655ab 100644
--- a/arguments.c
+++ b/arguments.c
@@ -51,15 +51,6 @@ struct args {
 	struct args_value	*values;
 };
 
-/* Prepared command state. */
-struct args_command_state {
-	struct cmd_parse_tree	*tree;
-	char			*cmd;
-	struct cmd_parse_input	 pi;
-	char			*error;
-	int			 parse_input;
-};
-
 static struct args_entry	*args_find(struct args *, u_char);
 
 static int	args_cmp(struct args_entry *, struct args_entry *);
@@ -748,151 +739,53 @@ args_string(struct args *args, u_int idx)
 	return (args_value_as_string(&args->values[idx]));
 }
 
-/* Make a command now. */
-struct cmdq_item *
-args_command_now(struct cmd *self, struct cmdq_item *item, u_int idx,
-    int expand)
+/*
+ * Convert one command argument into a parse tree. A string value is parsed;
+ * existing commands are referenced.
+ */
+struct cmd_parse_tree *
+args_to_commands(struct cmd *self, struct cmdq_item *item, u_int idx,
+    const char *default_command, int expand, char **cause)
 {
-	struct args_command_state	*state;
-	struct cmdq_item		*new_item;
-	struct cmdq_state		*cs = cmdq_get_state(item);
-	char				*error;
+	struct args		*args = cmd_get_args(self);
+	struct args_value	*value;
+	struct cmd_parse_input	 pi = { 0 };
+	const char		*cmd = NULL, *file;
+	char			*expanded;
+	struct cmd_parse_tree	*tree;
 
-	state = args_command_prepare(self, item, idx, NULL, expand);
-	new_item = args_command_get(state, 0, NULL, cs, &error);
-	if (new_item == NULL) {
-		cmdq_error(item, "%s", error);
-		free(error);
-	}
-	args_command_free(state);
-	return (new_item);
-}
+	*cause = NULL;
 
-/* Save bits to make a command later. */
-struct args_command_state *
-args_command_prepare(struct cmd *self, struct cmdq_item *item, u_int idx,
-    const char *default_command, int expand)
-{
-	struct args			*args = cmd_get_args(self);
-	struct args_value		*value;
-	struct args_command_state	*state;
-	const char			*cmd = NULL;
-	const char			*file;
-
-	state = xcalloc(1, sizeof *state);
-	state->pi.flags = cmd_get_parse_flags(self);
-
-	cmd_get_source(self, &file, &state->pi.line);
-	if (file != NULL)
-		state->pi.file = xstrdup(file);
-
-	if (idx < args->count) {
-		value = &args->values[idx];
-		if (value->type == ARGS_COMMANDS) {
-			state->tree = cmd_parse_add_ref(value->cmd);
-			return (state);
-		}
-		if (value->type != ARGS_STRING)
-			fatalx("argument not string or commands");
-		cmd = value->string;
-	} else {
-		if (default_command == NULL)
-			fatalx("argument out of range");
+	if (idx >= args->count)
 		cmd = default_command;
+	else {
+		value = &args->values[idx];
+		switch (value->type) {
+		case ARGS_COMMANDS:
+			return (cmd_parse_add_ref(value->cmd));
+		case ARGS_STRING:
+			cmd = value->string;
+			break;
+		case ARGS_NONE:
+			break;
+		}
 	}
-
+	if (cmd == NULL)
+		fatalx("argument out of range");
 
 	if (expand)
-		state->cmd = format_single_from_target(item, cmd);
+		expanded = format_single_from_target(item, cmd);
 	else
-		state->cmd = xstrdup(cmd);
-	log_debug("%s: %s", __func__, state->cmd);
+		expanded = xstrdup(cmd);
+	log_debug("%s: %s", __func__, expanded);
 
-	if (strcmp(state->cmd, "%1") == 0)
-		state->parse_input = 1;
-	else {
-		state->tree = cmd_parse_from_string(state->cmd, &state->pi,
-		    &state->error);
-	}
-
-	return (state);
-}
-
-/* Return argument as command queue item. */
-struct cmdq_item *
-args_command_get(struct args_command_state *state, int argc, char **argv,
-    struct cmdq_state *qstate, char **error)
-{
-	struct cmd_invoke_input	ci = { 0 };
-	struct cmd_parse_tree	*tree;
-	struct cmdq_item	*item;
-	int			 free_tree = 0;
-
-	if (state->error != NULL) {
-		*error = xstrdup(state->error);
-		return (NULL);
-	}
-
-	ci.file = state->pi.file;
-	ci.flags = state->pi.flags;
-
-	if (state->parse_input) {
-		if (argc == 0 || argv[0] == NULL) {
-			*error = xstrdup("missing command");
-			return (NULL);
-		}
-		tree = cmd_parse_from_string(argv[0], &state->pi, error);
-		if (tree == NULL)
-			return (NULL);
-		free_tree = 1;
-	} else {
-		if (state->tree == NULL)
-			fatalx("no command tree");
-		tree = state->tree;
-		ci.argc = argc;
-		ci.argv = argv;
-	}
-
-	item = cmd_invoke_get(tree, qstate, &ci);
-	if (free_tree)
-		cmd_parse_free(tree);
-	return (item);
-}
-
-/* Free commands state. */
-void
-args_command_free(struct args_command_state *state)
-{
-	if (state->tree != NULL)
-		cmd_parse_free(state->tree);
-	free((void *)state->pi.file);
-	free(state->cmd);
-	free(state->error);
-	free(state);
-}
-
-/* Get prepared command. */
-char *
-args_command_get_command(struct args_command_state *state)
-{
-	int	 n;
-	char	*s, *tmp;
-
-	if (state->parse_input)
-		return (xstrdup(""));
-	if (state->cmd == NULL && state->tree != NULL) {
-		tmp = cmd_parse_print(state->tree);
-		n = strcspn(tmp, " ,");
-		xasprintf(&s, "%.*s", n, tmp);
-		free(tmp);
-		return (s);
-	}
-	if (state->cmd != NULL) {
-		n = strcspn(state->cmd, " ,");
-		xasprintf(&s, "%.*s", n, state->cmd);
-		return (s);
-	}
-	return (xstrdup(""));
+	cmd_get_source(self, &file, &pi.line);
+	if (file != NULL)
+		pi.file = file;
+	pi.flags = cmd_get_parse_flags(self);
+	tree = cmd_parse_from_string(expanded, &pi, cause);
+	free(expanded);
+	return (tree);
 }
 
 /* Get first value in argument. */
diff --git a/cmd-command-prompt.c b/cmd-command-prompt.c
index 617cc4514..845985239 100644
--- a/cmd-command-prompt.c
+++ b/cmd-command-prompt.c
@@ -57,7 +57,7 @@ struct cmd_command_prompt_prompt {
 
 struct cmd_command_prompt_cdata {
 	struct cmdq_item		 *item;
-	struct args_command_state	 *state;
+	struct cmd_parse_tree		 *tree;
 
 	int				  flags;
 	enum prompt_type		  prompt_type;
@@ -85,13 +85,13 @@ cmd_command_prompt_exec(struct cmd *self, struct cmdq_item *item)
 	struct args			*args = cmd_get_args(self);
 	struct client			*tc = cmdq_get_target_client(item);
 	struct cmd_find_state		*target = cmdq_get_target(item);
-	const char			*type, *s, *input;
+	const char			*type, *s, *input, *cmd;
 	struct cmd_command_prompt_cdata *cdata;
 	char				*tmp, *prompts, *prompt, *next_prompt;
-	char				*inputs = NULL, *next_input;
+	char				*inputs = NULL, *next_input, *cause = NULL;
 	struct window_pane		*wp = target->wp;
 	u_int				 count = args_count(args);
-	int				 wait = !args_has(args, 'b'), space = 1;
+	int				 wait = !args_has(args, 'b'), space = 1, n;
 	int				 pane = args_has(args, 'P');
 
 	if (pane) {
@@ -107,14 +107,22 @@ cmd_command_prompt_exec(struct cmd *self, struct cmdq_item *item)
 		cdata->item = item;
 	if (pane)
 		cdata->wp = wp;
-	cdata->state = args_command_prepare(self, item, 0, "%1",
-	    args_has(args, 'F'));
+	if (count != 0) {
+		cdata->tree = args_to_commands(self, item, 0, NULL,
+		    args_has(args, 'F'), &cause);
+		if (cdata->tree == NULL) {
+			cmdq_error(item, "%s", cause);
+			free(cause);
+			free(cdata);
+			return (CMD_RETURN_ERROR);
+		}
+	}
 
 	if ((s = args_get(args, 'p')) == NULL) {
 		if (count != 0) {
-			tmp = args_command_get_command(cdata->state);
-			xasprintf(&prompts, "(%s)", tmp);
-			free(tmp);
+			cmd = args_string(args, 0);
+			n = strcspn(cmd, " ,");
+			xasprintf(&prompts, "(%.*s)", n, cmd);
 		} else {
 			prompts = xstrdup(":");
 			space = 0;
@@ -203,6 +211,9 @@ cmd_command_prompt_callback(struct client *c, void *data, const char *s,
 	struct cmdq_item			 *item = cdata->item, *new_item;
 	struct cmdq_state			 *cs = NULL;
 	struct cmd_command_prompt_prompt	 *prompt;
+	struct cmd_invoke_input			  ci = { 0 };
+	struct cmd_parse_tree			 *tree;
+	struct cmd_parse_input			  pi = { 0 };
 	int					  argc = 0;
 	char					**argv = NULL;
 
@@ -237,14 +248,33 @@ cmd_command_prompt_callback(struct client *c, void *data, const char *s,
 
 	if (item != NULL)
 		cs = cmdq_get_state(item);
-	new_item = args_command_get(cdata->state, argc, argv, cs, &error);
-	if (new_item == NULL) {
-		cmdq_append(c, cmdq_get_error(error));
-		free(error);
-	} else if (item == NULL) {
-		cmdq_append(c, new_item);
+
+	if (cdata->tree != NULL) {
+		/* Explicit body: prompt inputs become the template argv. */
+		ci.argc = argc;
+		ci.argv = argv;
+		new_item = cmd_invoke_get(cdata->tree, cs, &ci);
+		if (item == NULL)
+			cmdq_append(c, new_item);
+		else
+			cmdq_insert_after(item, new_item);
 	} else {
-		cmdq_insert_after(item, new_item);
+		/* No body: parse the submitted text as command language. */
+		tree = cmd_parse_from_string(s, &pi, &error);
+		if (tree == NULL) {
+			if (item == NULL)
+				cmdq_append(c, cmdq_get_error(error));
+			else
+				cmdq_error(item, "%s", error);
+			free(error);
+		} else {
+			new_item = cmd_invoke_get(tree, cs, NULL);
+			cmd_parse_free(tree);
+			if (item == NULL)
+				cmdq_append(c, new_item);
+			else
+				cmdq_insert_after(item, new_item);
+		}
 	}
 	cmd_free_argv(argc, argv);
 
@@ -281,6 +311,6 @@ cmd_command_prompt_free(void *data)
 	}
 	free(cdata->prompts);
 	cmd_free_argv(cdata->argc, cdata->argv);
-	args_command_free(cdata->state);
+	cmd_parse_free(cdata->tree);
 	free(cdata);
 }
diff --git a/cmd-confirm-before.c b/cmd-confirm-before.c
index 9c6326947..0109b8292 100644
--- a/cmd-confirm-before.c
+++ b/cmd-confirm-before.c
@@ -50,10 +50,10 @@ const struct cmd_entry cmd_confirm_before_entry = {
 };
 
 struct cmd_confirm_before_data {
-	struct cmdq_item		*item;
-	struct args_command_state	*state;
-	u_char				 confirm_key;
-	int				 default_yes;
+	struct cmdq_item	*item;
+	struct cmd_parse_tree	*tree;
+	u_char			 confirm_key;
+	int			 default_yes;
 };
 
 static enum args_parse_type
@@ -70,13 +70,18 @@ cmd_confirm_before_exec(struct cmd *self, struct cmdq_item *item)
 	struct cmd_confirm_before_data	*cdata;
 	struct client			*tc = cmdq_get_target_client(item);
 	struct cmd_find_state		*target = cmdq_get_target(item);
-	char				*new_prompt;
-	const char			*confirm_key, *prompt;
-	char				*cmd;
-	int				 wait = !args_has(args, 'b');
+	char				*new_prompt, *cause = NULL;
+	const char			*confirm_key, *prompt, *cmd;
+	int				 wait = !args_has(args, 'b'), n;
 
 	cdata = xcalloc(1, sizeof *cdata);
-	cdata->state = args_command_prepare(self, item, 0, NULL, 1);
+	cdata->tree = args_to_commands(self, item, 0, NULL, 1, &cause);
+	if (cdata->tree == NULL) {
+		cmdq_error(item, "%s", cause);
+		free(cause);
+		free(cdata);
+		return (CMD_RETURN_ERROR);
+	}
 
 	if (wait)
 		cdata->item = item;
@@ -89,7 +94,7 @@ cmd_confirm_before_exec(struct cmd *self, struct cmdq_item *item)
 			cdata->confirm_key = confirm_key[0];
 		else {
 			cmdq_error(item, "invalid confirm key");
-			args_command_free(cdata->state);
+			cmd_parse_free(cdata->tree);
 			free(cdata);
 			return (CMD_RETURN_ERROR);
 		}
@@ -100,10 +105,10 @@ cmd_confirm_before_exec(struct cmd *self, struct cmdq_item *item)
 	if ((prompt = args_get(args, 'p')) != NULL)
 		xasprintf(&new_prompt, "%s ", prompt);
 	else {
-		cmd = args_command_get_command(cdata->state);
-		xasprintf(&new_prompt, "Confirm '%s'? (%c/n) ", cmd,
+		cmd = args_string(args, 0);
+		n = strcspn(cmd, " ,");
+		xasprintf(&new_prompt, "Confirm '%.*s'? (%c/n) ", n, cmd,
 		    cdata->confirm_key);
-		free(cmd);
 	}
 
 	status_prompt_set(tc, target, new_prompt, NULL,
@@ -122,7 +127,6 @@ cmd_confirm_before_callback(struct client *c, void *data, const char *s,
 {
 	struct cmd_confirm_before_data	*cdata = data;
 	struct cmdq_item		*item = cdata->item, *new_item;
-	char				*error;
 	int				 retcode = 1;
 
 	if (c->flags & CLIENT_DEAD)
@@ -135,22 +139,11 @@ cmd_confirm_before_callback(struct client *c, void *data, const char *s,
 	retcode = 0;
 
 	if (item == NULL) {
-		new_item = args_command_get(cdata->state, 0, NULL, NULL,
-		    &error);
-		if (new_item == NULL) {
-			cmdq_append(c, cmdq_get_error(error));
-			free(error);
-			goto out;
-		}
+		new_item = cmd_invoke_get(cdata->tree, NULL, NULL);
 		cmdq_append(c, new_item);
 	} else {
-		new_item = args_command_get(cdata->state, 0, NULL,
-		    cmdq_get_state(item), &error);
-		if (new_item == NULL) {
-			cmdq_error(item, "%s", error);
-			free(error);
-			goto out;
-		}
+		new_item = cmd_invoke_get(cdata->tree, cmdq_get_state(item),
+		    NULL);
 		cmdq_insert_after(item, new_item);
 	}
 
@@ -169,6 +162,6 @@ cmd_confirm_before_free(void *data)
 {
 	struct cmd_confirm_before_data	*cdata = data;
 
-	args_command_free(cdata->state);
+	cmd_parse_free(cdata->tree);
 	free(cdata);
 }
diff --git a/cmd-display-panes.c b/cmd-display-panes.c
index b2f56c488..db7a87fbe 100644
--- a/cmd-display-panes.c
+++ b/cmd-display-panes.c
@@ -44,8 +44,8 @@ const struct cmd_entry cmd_display_panes_entry = {
 };
 
 struct cmd_display_panes_data {
-	struct cmdq_item		*item;
-	struct args_command_state	*state;
+	struct cmdq_item	*item;
+	struct cmd_parse_tree	*tree;
 };
 
 struct cmd_display_panes_ctx {
@@ -297,7 +297,7 @@ cmd_display_panes_free(__unused struct client *c, void *data)
 
 	if (cdata->item != NULL)
 		cmdq_continue(cdata->item);
-	args_command_free(cdata->state);
+	cmd_parse_free(cdata->tree);
 	free(cdata);
 }
 
@@ -305,9 +305,9 @@ static int
 cmd_display_panes_key(struct client *c, void *data, struct key_event *event)
 {
 	struct cmd_display_panes_data	*cdata = data;
-	char				*expanded, *error;
+	char				*expanded;
+	struct cmd_invoke_input		 ci = { 0 };
 	struct cmdq_item		*item = cdata->item, *new_item;
-	struct cmdq_state		*cs = NULL;
 	struct window			*w = c->session->curw->window;
 	struct window_pane		*wp;
 	u_int				 index;
@@ -330,20 +330,14 @@ cmd_display_panes_key(struct client *c, void *data, struct key_event *event)
 	window_unzoom(w, 1);
 
 	xasprintf(&expanded, "%%%u", wp->id);
+	ci.argc = 1;
+	ci.argv = &expanded;
 
-	if (item != NULL)
-		cs = cmdq_get_state(item);
-	new_item = args_command_get(cdata->state, 1, &expanded, cs,
-	    &error);
-	if (new_item == NULL) {
-		cmdq_append(c, cmdq_get_error(error));
-		free(error);
-	} else {
-		if (item == NULL)
-			cmdq_append(c, new_item);
-		else
-			cmdq_insert_after(item, new_item);
-	}
+	new_item = cmd_invoke_get(cdata->tree, cmdq_get_state(item), &ci);
+	if (item == NULL)
+		cmdq_append(c, new_item);
+	else
+		cmdq_insert_after(item, new_item);
 
 	free(expanded);
 	return (1);
@@ -363,21 +357,28 @@ cmd_display_panes_exec(struct cmd *self, struct cmdq_item *item)
 	if (tc->overlay_draw != NULL)
 		return (CMD_RETURN_NORMAL);
 
-	if (args_has(args, 'd')) {
+	if (!args_has(args, 'd'))
+		delay = options_get_number(s->options, "display-panes-time");
+	else {
 		delay = args_strtonum(args, 'd', 0, UINT_MAX, &cause);
 		if (cause != NULL) {
 			cmdq_error(item, "delay %s", cause);
 			free(cause);
 			return (CMD_RETURN_ERROR);
 		}
-	} else
-		delay = options_get_number(s->options, "display-panes-time");
+	}
 
 	cdata = xcalloc(1, sizeof *cdata);
 	if (wait)
 		cdata->item = item;
-	cdata->state = args_command_prepare(self, item, 0,
-	    "select-pane -t \"%%%\"", 0);
+	cdata->tree = args_to_commands(self, item, 0, "select-pane -t \"%%%\"",
+	    0, &cause);
+	if (cdata->tree == NULL) {
+		cmdq_error(item, "%s", cause);
+		free(cause);
+		free(cdata);
+		return (CMD_RETURN_ERROR);
+	}
 
 	if (args_has(args, 'N')) {
 		server_client_set_overlay(tc, delay, NULL, NULL,
diff --git a/cmd-if-shell.c b/cmd-if-shell.c
index 3cd9829ad..216bca55b 100644
--- a/cmd-if-shell.c
+++ b/cmd-if-shell.c
@@ -53,11 +53,11 @@ const struct cmd_entry cmd_if_shell_entry = {
 };
 
 struct cmd_if_shell_data {
-	struct args_command_state	*cmd_if;
-	struct args_command_state	*cmd_else;
+	struct cmd_parse_tree	*cmd_if;
+	struct cmd_parse_tree	*cmd_else;
 
-	struct client			*client;
-	struct cmdq_item		*item;
+	struct client		*client;
+	struct cmdq_item	*item;
 };
 
 static enum args_parse_type
@@ -76,42 +76,58 @@ cmd_if_shell_exec(struct cmd *self, struct cmdq_item *item)
 	struct cmd_find_state		*target = cmdq_get_target(item);
 	struct cmd_if_shell_data	*cdata;
 	struct cmdq_item		*new_item;
-	char				*shellcmd;
+	struct cmd_parse_tree		*tree;
+	char				*shellcmd, *cause = NULL;
 	struct client			*tc = cmdq_get_target_client(item);
 	struct session			*s = target->s;
-	u_int				 count = args_count(args);
+	u_int				 count = args_count(args), idx;
 	int				 wait = !args_has(args, 'b');
 
 	shellcmd = format_single_from_target(item, args_string(args, 0));
 	if (args_has(args, 'F')) {
 		if (*shellcmd != '0' && *shellcmd != '\0')
-			new_item = args_command_now(self, item, 1, 0);
+			idx = 1;
 		else if (count == 3)
-			new_item = args_command_now(self, item, 2, 0);
+			idx = 2;
 		else {
 			free(shellcmd);
 			return (CMD_RETURN_NORMAL);
 		}
 		free(shellcmd);
-		if (new_item == NULL)
+
+		tree = args_to_commands(self, item, idx, NULL, 0, &cause);
+		if (tree == NULL) {
+			cmdq_error(item, "%s", cause);
+			free(cause);
 			return (CMD_RETURN_ERROR);
+		}
+		new_item = cmd_invoke_get(tree, cmdq_get_state(item), NULL);
+		cmd_parse_free(tree);
 		cmdq_insert_after(item, new_item);
 		return (CMD_RETURN_NORMAL);
 	}
 
 	cdata = xcalloc(1, sizeof *cdata);
-
-	cdata->cmd_if = args_command_prepare(self, item, 1, NULL, 0);
+	cdata->cmd_if = args_to_commands(self, item, 1, NULL, 0, &cause);
+	if (cdata->cmd_if == NULL) {
+		cmdq_error(item, "%s", cause);
+		goto fail;
+	}
 	if (count == 3) {
-		cdata->cmd_else = args_command_prepare(self, item, 2,
-		    NULL, 0);
+		cdata->cmd_else = args_to_commands(self, item, 2, NULL, 0,
+		    &cause);
+		if (cdata->cmd_else == NULL) {
+			cmdq_error(item, "%s", cause);
+			goto fail;
+		}
 	}
 
-	if (wait) {
+	if (!wait)
+		cdata->client = tc;
+	else {
 		cdata->client = cmdq_get_client(item);
 		cdata->item = item;
-	} else
-		cdata->client = tc;
+	}
 	if (cdata->client != NULL)
 		cdata->client->references++;
 
@@ -120,15 +136,19 @@ cmd_if_shell_exec(struct cmd *self, struct cmdq_item *item)
 	    cmd_if_shell_callback, cmd_if_shell_free, cdata, 0, -1,
 	    -1) == NULL) {
 		cmdq_error(item, "failed to run command: %s", shellcmd);
-		free(shellcmd);
-		cmd_if_shell_free(cdata);
-		return (CMD_RETURN_ERROR);
+		goto fail;
 	}
 	free(shellcmd);
 
 	if (!wait)
 		return (CMD_RETURN_NORMAL);
 	return (CMD_RETURN_WAIT);
+
+fail:
+	free(cause);
+	free(shellcmd);
+	cmd_if_shell_free(cdata);
+	return (CMD_RETURN_ERROR);
 }
 
 static void
@@ -137,35 +157,23 @@ cmd_if_shell_callback(struct job *job)
 	struct cmd_if_shell_data	*cdata = job_get_data(job);
 	struct client			*c = cdata->client;
 	struct cmdq_item		*item = cdata->item, *new_item;
-	struct cmdq_state		*cs = NULL;
-	struct args_command_state	*state;
-	char				*error;
+	struct cmd_parse_tree		*tree;
 	int				 status;
 
 	status = job_get_status(job);
 	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
-		state = cdata->cmd_else;
+		tree = cdata->cmd_else;
 	else
-		state = cdata->cmd_if;
-	if (state == NULL)
+		tree = cdata->cmd_if;
+	if (tree == NULL)
 		goto out;
 
-	if (item != NULL)
-		cs = cmdq_get_state(item);
-	new_item = args_command_get(state, 0, NULL, cs, &error);
-	if (new_item == NULL) {
-		if (cdata->item != NULL)
-			cmdq_error(cdata->item, "%s", error);
-		else {
-			*error = toupper((u_char)*error);
-			status_message_set(c, -1, 1, 0, 0, "%s", error);
-		}
-		free(error);
+	if (item == NULL) {
+		new_item = cmd_invoke_get(tree, NULL, NULL);
+		cmdq_append(c, new_item);
 	} else {
-		if (item == NULL)
-			cmdq_append(c, new_item);
-		else
-			cmdq_insert_after(item, new_item);
+		new_item = cmd_invoke_get(tree, cmdq_get_state(item), NULL);
+		cmdq_insert_after(item, new_item);
 	}
 
 out:
@@ -182,8 +190,8 @@ cmd_if_shell_free(void *data)
 		server_client_unref(cdata->client);
 
 	if (cdata->cmd_else != NULL)
-		args_command_free(cdata->cmd_else);
-	args_command_free(cdata->cmd_if);
-
+		cmd_parse_free(cdata->cmd_else);
+	if (cdata->cmd_if != NULL)
+		cmd_parse_free(cdata->cmd_if);
 	free(cdata);
 }
diff --git a/cmd-run-shell.c b/cmd-run-shell.c
index 547c44b95..e8328278e 100644
--- a/cmd-run-shell.c
+++ b/cmd-run-shell.c
@@ -55,15 +55,15 @@ const struct cmd_entry cmd_run_shell_entry = {
 };
 
 struct cmd_run_shell_data {
-	struct client			*client;
-	char				*cmd;
-	struct args_command_state	*state;
-	char				*cwd;
-	struct cmdq_item		*item;
-	struct session			*s;
-	int				 wp_id;
-	struct event			 timer;
-	int				 flags;
+	struct client		*client;
+	char			*cmd;
+	struct cmd_parse_tree	*tree;
+	char			*cwd;
+	struct cmdq_item	*item;
+	struct session		*s;
+	int			 wp_id;
+	struct event		 timer;
+	int			 flags;
 };
 
 static enum args_parse_type
@@ -118,7 +118,7 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 	struct format_tree		*ft;
 	double				 d;
 	struct timeval			 tv;
-	char				*end, key[16];
+	char				*end, key[16], *cause = NULL;
 	u_int				 i;
 	int				 wait = !args_has(args, 'b');
 
@@ -128,8 +128,10 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 			cmdq_error(item, "invalid delay time: %s", delay);
 			return (CMD_RETURN_ERROR);
 		}
-	} else if (args_count(args) == 0)
-		return (CMD_RETURN_NORMAL);
+	} else {
+		if (args_count(args) == 0)
+			return (CMD_RETURN_NORMAL);
+	}
 
 	cdata = xcalloc(1, sizeof *cdata);
 	if (!args_has(args, 'C')) {
@@ -144,8 +146,13 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 			format_free(ft);
 		}
 	} else {
-		cdata->state = args_command_prepare(self, item, 0, NULL,
-		    1);
+		cdata->tree = args_to_commands(self, item, 0, NULL, 1, &cause);
+		if (cdata->tree == NULL) {
+			cmdq_error(item, "%s", cause);
+			free(cause);
+			cmd_run_shell_free(cdata);
+			return (CMD_RETURN_ERROR);
+		}
 	}
 
 	if (args_has(args, 't') && wp != NULL)
@@ -162,6 +169,7 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 	}
 	if (cdata->client != NULL)
 		cdata->client->references++;
+
 	if (args_has(args, 'c'))
 		cdata->cwd = xstrdup(args_get(args, 'c'));
 	else
@@ -170,18 +178,20 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 	if (args_has(args, 'E'))
 		cdata->flags |= JOB_SHOWSTDERR;
 
-	cdata->s = s;
-	if (s != NULL)
+	if (s != NULL) {
+		cdata->s = s;
 		session_add_ref(s, __func__);
+	}
 
 	evtimer_set(&cdata->timer, cmd_run_shell_timer, cdata);
-	if (delay != NULL) {
+	if (delay == NULL)
+		event_active(&cdata->timer, EV_TIMEOUT, 1);
+	else {
 		timerclear(&tv);
 		tv.tv_sec = (time_t)d;
 		tv.tv_usec = (d - (double)tv.tv_sec) * 1000000U;
 		evtimer_add(&cdata->timer, &tv);
-	} else
-		event_active(&cdata->timer, EV_TIMEOUT, 1);
+	}
 
 	if (!wait)
 		return (CMD_RETURN_NORMAL);
@@ -196,9 +206,8 @@ cmd_run_shell_timer(__unused int fd, __unused short events, void* arg)
 	const char			*cmd = cdata->cmd;
 	struct cmdq_item		*item = cdata->item, *new_item;
 	struct cmdq_state		*cs = NULL;
-	char				*error;
 
-	if (cdata->state == NULL) {
+	if (cdata->tree == NULL) {
 		if (cmd == NULL) {
 			if (cdata->item != NULL)
 				cmdq_continue(cdata->item);
@@ -223,21 +232,11 @@ cmd_run_shell_timer(__unused int fd, __unused short events, void* arg)
 
 	if (item != NULL)
 		cs = cmdq_get_state(item);
-	new_item = args_command_get(cdata->state, 0, NULL, cs, &error);
-	if (new_item == NULL) {
-		if (cdata->item != NULL)
-			cmdq_error(cdata->item, "%s", error);
-		else {
-			*error = toupper((u_char)*error);
-			status_message_set(c, -1, 1, 0, 0, "%s", error);
-		}
-		free(error);
-	} else {
-		if (item == NULL)
-			cmdq_append(c, new_item);
-		else
-			cmdq_insert_after(item, new_item);
-	}
+	new_item = cmd_invoke_get(cdata->tree, cs, NULL);
+	if (item == NULL)
+		cmdq_append(c, new_item);
+	else
+		cmdq_insert_after(item, new_item);
 
 	if (cdata->item != NULL)
 		cmdq_continue(cdata->item);
@@ -305,8 +304,7 @@ cmd_run_shell_free(void *data)
 		session_remove_ref(cdata->s, __func__);
 	if (cdata->client != NULL)
 		server_client_unref(cdata->client);
-	if (cdata->state != NULL)
-		args_command_free(cdata->state);
+	cmd_parse_free(cdata->tree);
 	free(cdata->cwd);
 	free(cdata->cmd);
 	free(cdata);
diff --git a/tmux.h b/tmux.h
index dd2dd60c0..bffda3a44 100644
--- a/tmux.h
+++ b/tmux.h
@@ -40,7 +40,6 @@
 extern char   **environ;
 
 struct args;
-struct args_command_state;
 struct client;
 struct cmd;
 struct cmd_find_state;
@@ -2898,14 +2897,8 @@ u_int		 args_count(struct args *);
 struct args_value *args_values(struct args *);
 struct args_value *args_value(struct args *, u_int);
 const char	*args_string(struct args *, u_int);
-struct cmdq_item *args_command_now(struct cmd *, struct cmdq_item *,
-		     u_int, int);
-struct args_command_state *args_command_prepare(struct cmd *,
-		     struct cmdq_item *, u_int, const char *, int);
-struct cmdq_item *args_command_get(struct args_command_state *, int, char **,
-		     struct cmdq_state *, char **);
-void		 args_command_free(struct args_command_state *);
-char		*args_command_get_command(struct args_command_state *);
+struct cmd_parse_tree *args_to_commands(struct cmd *, struct cmdq_item *,
+		     u_int, const char *, int, char **);
 struct args_value *args_first_value(struct args *, u_char);
 struct args_value *args_next_value(struct args_value *);
 long long	 args_strtonum(struct args *, u_char, long long, long long,