Flint Butane, How do they work?

[Buckeye Jack]

I think I understand the concept of a flint/fluid lighter. The wick is soaked in the fluid, lights when a spark hits it.

I think I understand how a butane lighter works. With the click of a button or what not, it releases the gas which ignites when a spark is let off. When you release the button, the gas stops flowing.

Now I may be completely wrong about all of this (i've been known to be wrong before but is there a release/shutoff for the butane gas on a flint lighter? In my thinking, the gas would just be continuously coming out, which would obviously suck because you would be out of fuel all the time. All I can think of, everytime I have used one, is the spark mechanism, not on/off valve for the butane.

Anyone want to clarify this for me? Thanks!!