How do you fix a door that won't stay open or shut?

A regular door?! Brace the door, remove the top hinge pin with a screw driver and hammer. Lay the hinge pin flat on a hard surface. Lightly strike it with the hammer to put a slight bend in the pin. Reinsert the hinge pin. The bend creates friction to keep the door open or closed. May need to do this to the bottom pin.

I'd put a level on top of the door to find out precisely where it is out of plumb. Then you know where/how to readjust it.

https://www.google.com/search?q=how+to+level+a+door&rlz=1C1AOHY_enUS708US708&oq=how+to+level+a+door&aqs=chrome.0.0l6.3127j0j7&sourceid=chrome&ie=UTF-8

First see if the door has been hung onto a Straight Frame. Use a piece of string with a stone attached. Hold it at the top of the door frame, does it hang into or away from the door? If it does, then that is the problem. Of course you could use a large spirit level if you have one for the purpose.

I would first tighten up the hinge screws and give them a shot of WD40. Then I would try rubbing a bar of soap on the edges of the door.

adjust striker --door sage

Thanks everyone. I will try these out and hopefully one will work. It is my bedroom door. I would have it shut at night but I have a kitten who has to be able to come and go or he will make me get up and let him in and out. I hate having the door open all the way and it will not stay shut part of the way without something behind hit to prevent it from opening all the way.

use Point Chisel, create a small dimple in one of the hinges that will increase friction, door stays as desired. Multiple hinges, often does not break off paint.