Add command union and name of the disk to be associated with.

libguestfs-inspect.h

@@ -1,11 +1,23 @@
 enum guestfs_inspect_command {
   GUESTFS_COMMAND_LS,
-  GUESTFS_COMMAND_TOUCH,
+  /* GUESTFS_COMMAND_TOUCH, */
-  GUESTFS_COMMAND_MKDIR,
+  /* GUESTFS_COMMAND_MKDIR, */
   GUESTFS_COMMAND_CAT
 };
 
+struct guestfs_ls_args {
+  size_t path_length;
+  char path[];
+};
+struct guestfs_cat_args {};
+
 struct guestfs_inpsect_command {
   enum guestfs_inspect_command command;
+  union {
+    struct guestfs_ls_args ls;
+    struct guestfs_cat_args cat;
+  } args;
+  size_t name_length;
+  char name[];
 };