How do I Grab the Walls

I need know how to grab the wall like in demons crest, when you grab the wall you can shoot and to leave him need jump

Like that:

Because this is in beginner's questions I don't know what you know in C2 but you can do this with the platform behaviour, when you jump onto a wall, set vectorx to 0, vectory to 0 and gravity to 0, it will be like you are stuck to the wall. Then you need some logic in for when you jump away from the wall (up arrow pressed), reset the vector and gravity values.