Let's restrict this question to rockets whose first stage :
- run on liquid propellant
- use turbopump (this may be too restrictive for this question, but it still restrict to many rockets in use today -in 2019- )
- use gimbal for attitude control
Those restriction still let many rockets all over the world (PSLV, Ariane V,...)
As gimbal is used to orient the entire engine (or at least the combustion chamber and the nozzle), the feed pipes going from the tanks (fix relative to the rocket stage) to the combustion chamber (moving relative to the rocket stage), pipes must allow such movements. How is it done? Is it done through flexible pipes?