Here is (most of) the California law that would apply to your situation:
"626.10. (b) Any person, except a duly appointed peace officer as defined
in Chapter 4.5 (commencing with Section 830) of Title 3 of Part 2, a
full-time paid peace officer of another state or the federal
government who is carrying out official duties while in this state, a
person summoned by any officer to assist in making arrests or
preserving the peace while the person is actually engaged in
assisting any officer, or a member of the military forces of this
state or the United States who is engaged in the performance of his
or her duties, who brings or possesses any dirk, dagger, ice pick, or
knife having a fixed blade longer than 21/2 inches upon the grounds
of, or within, any private university, the University of California,
the California State University, or the California Community Colleges
is guilty of a public offense, punishable by imprisonment in a
county jail not exceeding one year, or by imprisonment in the state
prison.
(c) Subdivisions (a) and (b) do not apply to any person who brings
or possesses a knife having a blade longer than 21/2 inches or a
razor with an unguarded blade upon the grounds of, or within, a
public or private school providing instruction in kindergarten or any
of grades 1 to 12, inclusive, or any private university, state
university, or community college at the direction of a faculty member
of the private university, state university, or community college,
or a certificated or classified employee of the school for use in a
private university, state university, community college, or
school-sponsored activity or class.
(d) Subdivisions (a) and (b) do not apply to any person who brings
or possesses an ice pick, a knife having a blade longer than 21/2
inches, or a razor with an unguarded blade upon the grounds of, or
within, a public or private school providing instruction in
kindergarten or any of grades 1 to 12, inclusive, or any private
university, state university, or community college for a lawful
purpose within the scope of the person's employment.
(e) Subdivision (b) does not apply to any person who brings or
possesses an ice pick or a knife having a fixed blade longer than
21/2 inches upon the grounds of, or within, any private university,
state university, or community college for lawful use in or around a
residence or residential facility located upon those grounds or for
lawful use in food preparation or consumption."
Note that 2 1/2 " is the magic number. In section a of this regulation, the prohibited objects are listed as "dirk, dagger, ice pick, knife having a blade longer than 21/2 inches, folding knife with a blade that locks into place, a razor with an unguarded blade, a taser, or a stun gun" which seems to differentiate between fixed blade and locking folder (both illegal over 2 1/2"), and a non-locking folder, which might not be illegal.
Best advice: Don't carry anything on campus which you know to be illegal; keep your knife low profile; keep your knife use very low profile; don't EVER pull a knife on someone, unless it's a life-or-death situation. (One student here pulled a knife on someone "jokingly" in some casual dorm wrestling play, and found himself very quickly facing a number of deputy sheriffs and a felony charge. Not fun!)