California Code, Penal Code - PEN § 16470

As used in this part, “dirk” or “dagger” means a knife or other instrument with or without a handguard that is capable of ready use as a stabbing weapon that may inflict great bodily injury or death. A nonlocking folding knife, a folding knife that is not prohibited by Section 21510, or a pocketknife is capable of ready use as a stabbing weapon that may inflict great bodily injury or death only if the blade of the knife is exposed and locked into position.