I like pull-ups. They are an important part of most athletic training for upper body development. You should never live somewhere you cannot do pull ups. A home without a pull-up bar in the modern world confuses me as much as a home without electricity or running water. Unfortunately, not all landlords agree so before I bought my first house I had to build a solid pull-up bar. This mechanism pressure-fits between the studs in a hallway to provide horizontal stability in two directions. Vertical stability is provided by 2x4s which rest on the flooring.
To prevent the plywood from scraping up the wall I recommend taping a sheet of wax paper to the wall, then a towel, then the plywood compression mechanism. The towel provides a cushion and the wax paper prevents the towel from bonding with the paint on the drywall which can happen if the towel is compressed into the paint for months or years. It can ruin the drywall underneath so put down wax paper.
Hazards If you use a steel bar which is not girthy enough relative to its length to support your weight without bowing, this system will fall apart as you apply your bodyweight. I used a 2" piece of gas pipe which easily supported 300 lbs. Design carefully, test carefully, and you should be fine.