First little hiccup you might have been hindered by is that starting this year, the State legislature changed all the numbers of the existing laws. So virtually all the secondary sources on the law are probably out of date.
Like all laws, the absolutely most reliable source is the state legislatures site:
http://www.leginfo.ca.gov/calaw.html
It's free and completely public. Knife laws are under the Penal Code. I can't link directly to them but I can tell you where to look and what there is to find.
Here's a simple breakdown at the state level though, by knife type. Numbers indicate the relevant statute from the Penal Code:
Switchblades and butterfly knives If the blade is less than 2 inches long, it's legal to buy, sell, own and carry. Go nuts. If the blade is longer than 2 inches, you can own and buy. But it is illegal to sell them or carry them, including in a car's passenger compartment. (
17235, 21510)
Assisted Openers - Considered the same as regular folders, so long as they have a bias towards closure (which almost all AOs do). (
17235)
Folders - Legal all around to carry. No size limit, no age limit. Illegal to carry with the blade locked open already (shows preparation to use it for attack). (
16470)
Fixed blades - Legal to buy, sell, own and carry
openly. Illegal to carry concealed. Open carry is commonly described in this state's legal records as in a sheath hung from the belt, with no clothing covering the handle such that it is readily identifiable as a knife. (
21310, 20200)
Truth be told the laws really have not changed much over the past few years other than the numbering scheme.
As usual, when you live in a specific area of a state, you are subject to the state's laws and the local laws as well. Just like they taught you in social studies: If the big area doesn't have a law on it, the smaller areas within can make their own that are more restrictive.
San Francisco just has a weird law that you can't loiter or get in fights when you have a knife with a blade over 3 inches. And you can't sell knives to minors.
