"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."

No double edge needed to be a dirk/dagger. Even your open pocket knife is one it seems.