Knife Carry Related Laws- California penal code has two main sections interesting to us in this discussion: 653K and 12020. 653Kbelongs to the section 639-653.2 - Of Other And Miscellaneous Offenses and 12020 belongs to the section 12020-12040 - Unlawful Carrying and Possession of Weapons, that is in the link provided at the beginning of this paragraph. Penal code 653K defines what is a legal pocket knife and what is a switchblade and gravity or ballisong knife. Pocket knives, most likely that'd be a folding knife are legal, while switchblades, gravity and ballisong knives are illegal. Penal code 12020 deals with the street carry laws. There are other penal codes dealing with knife carry in specific places. Those are: penal code 626.10 which deals with the knife school carry rules. There is also penal code 171.b which deals with the knives in public buildings.
Very Short Summary
653K- Defines legal and illegal pocket knives. Full text of the penal code 653K. The most interesting part of the penal code is the following definition of the switchblade knives:
12020- Deals with knife carry and prohibits several types of knives. Code 12020 is way too long to cite it here completely, thus only the most relevant parts here. For The reference - full text of the penal code 12020.
(1) Manufactures or causes to be manufactured, imports into the state, keeps for sale, or offers or exposes for sale, or who gives, lends, or possesses ... any ballistic knife, ... any belt buckle knife, any lipstick case knife, any cane sword, any shobi-zue, any air gauge knife, any writing pen knife, ...
So, not only you can't carry, but you can't even posses any of the listed in above. Some of it makes sense, some not so much. THe same section bans slungshots, but slingshots are ok. Yup, that's right, no slingies in California. Half of those things are most likely unknown to general public and probably knife enthusiastas as well. For your information, Shurikens are also included in this section. They are not exactly knives, but still edged weapons. Ok, moving on.
171.b- Tells you what you can and can not carry in public buildings and meetings. For the reference - Full Text Of Penal Code 171. 171.b starts with:
(a) Any person who brings or possesses within any state or local public building or at any meeting required to be open to the public pursuant to Chapter 9 (commencing with Section 54950) of Part 1 of Division 2 of Title 5 of, or Article 9 (commencing with Section 11120) of Chapter 1 of Part 1 of Division 3 of Title 2 of, the Government Code, any of the following is guilty of a public offense punishable by imprisonment in a county jail for not more than one year, or in the state prison:
(1) Any firearm.
(2) Any deadly weapon described in Section 653k or 12020.
(3) Any knife with a blade length in excess of four inches, the blade of which is fixed or is capable of being fixed in an unguarded position by the use of one or two hands.
Thus no knives longer than 4" in state and public buildings. Exact definition of the state or local public meeting and open to public buildings can be found in 171.b(c). In short, those are state or local government owned or leased buildings such as courts, police stations, city halls, etc. Meetings mean wherever those officials get together to conduct regular or irregular work, e.g. city council meetings.