Would it be legal to carry a 2 inch keychain knife in Australia?

The blade on my Swiss army knife is longer and those are also designed to be carried on a keychain, although I heard about an elderly guy who got charged for having one of those in Sydney as part of an anti-knoife crackdown. I have no idea if laws like this are only used against people acting like maniacs in public or if any random person could realistically get in trouble.