I'm looking to make a basic solana program with just some slight modifications from the spl token program.
Is there an example of importing the spl program and then adding a function?
SPL-Token is a program that is currently used as the token standard on Solana. In order to add additional functionality to the program, you have to either:
You can find an example of wrapping some of the existing SPL-Token instructions with another program in these program examples.
It all depends on the functionality you want to add.
There is an upcoming token22 standard that allows extensions to be added, but the functionality is still set to a few different extensions. The preferred way to add functionality is still listed in the 2 options above.