My question is if this candidate passwords are stored in some file where i can see it.
For example, cracking passwords are saved in john.pot

Hi, do you know if in john the ripper is possible to store all guesses and not just cracked ones?

I want to make a modification in the process of verifying a possible password (not in the generation) to compare different options when checking if a password exists or not.
Could you do it with external mode? or by modifying the code itself, and in this case in which file this check is made.