diff --git a/stand/common/bootstrap.h b/stand/common/bootstrap.h
--- a/stand/common/bootstrap.h
+++ b/stand/common/bootstrap.h
@@ -52,6 +52,7 @@
 void	interact(void);
 void	interp_emit_prompt(void);
 int	interp_builtin_cmd(int argc, char *argv[]);
+bool	interp_has_builtin_cmd(const char *cmd);
 
 /* Called by interp.c for interp_*.c embedded interpreters */
 int	interp_include(const char *);	/* Execute commands from filename */
diff --git a/stand/common/interp.c b/stand/common/interp.c
--- a/stand/common/interp.c
+++ b/stand/common/interp.c
@@ -190,3 +190,12 @@
 	}
 	return (result);
 }
+
+/*
+ * Return true if the builtin command exists
+ */
+bool
+interp_has_builtin_cmd(const char *cmd)
+{
+	return (interp_lookup_cmd(cmd) != NULL);
+}