I`m designing a circuit and I want to turn it on and off. I have two linear regulator and a step-up switch regulator in it. If I use a switch that connects the input pin of the regulator to the battery positive pole or open it, do I have a ON/OFF button or can I have malfunction doing so?
If your switch is momentary then there are some additional complexities. Linear has some nice ICs if you want to avoid any headaches with this and make it a pretty "brain dead" design.
They have nice schematics in there that show you exactly how to do what you're trying to do. If it's not a momentary switch then of course the answer that Samuel provided above is great.