I don't live in San Antonio, but I have to tell you that I would carry a lockblade knife and never think twice about it. Like others have mentioned, I am willing to bet that this is a seldom enforced law, and it's one of those things that I just generally ignore. Why? Well, honestly put, I don't look or act like the type of person from whom the police could expect trouble. I don't do things that would get me caught with a locking blade knife. Even on the off chance that some policeman did see it and did bring it to my attention, I have a hard time believing that I would even be arrested, let alone convicted, of any crime.
But, thats just me. THR does not encourage people to break the law, and I am not suggesting anyone do so. I am simply saying that I would break it if I lived there, because it's just not something that I think would realistically ever be an issue for me.