Most of California follows state law regarding knives, some counties and cities have their own seperate laws.
Down here in San Diego county all we have is state law. Down here we can carry ANY SIZE folder conceald or openly (as long as the blade of the conceald folder isn't in the open and locked position. And as long as it isn't a gravilty knife, or a switchblade with a blade 2 inches or longer.
We can also carry a fixed-blade of ANY SIZE or design as long as we carry it openly
I've been living in San Diego for the past 42 years, I ride a motorcyle everyday wherever I go, my riding gear is old and somewhat ragged, I'm not clean-shaven, I've been carrying a fixed-blade openly for the past 7 years, several cops have seen me carrying it, none of them have ever said a negative word about it, asked to see my ID, or given me any hassle whatsoever.
The only time a cop ever stopped me because of my knife is when part of my motorcycle jacket momentarily coverd the knife and he warned me that technically it could be considerd "conceald" as a result. He never took the knife from me, never asked for my name or ID, he just gave me a friendly warning with a smile and I was on my way down the road.
I love San Diego, our knife laws, and the freedom we enjoy are great.