I have been feeding a friendly feral cat for the last 10 months. He began visiting us when he was well into his feline teens, so to speak (so he can forage food for himself). He is not exactly a lap kitty, but loves being stroked and can be lifted for upto 30 seconds at a stretch. In the daytime, I usually leave the window open for him to come and go as he pleases. He spends the day indoors napping after I give him his meal. Around 11 pm every evening, he wakes up and gets restless, which is when I have to let him outside. He spends the night outside and comes back in the morning to repeat the nap-eat-nap schedule.
The problem is that I am going to be moving houses in 15 days and I would really like to take him along. I am okay with keeping him indoors and litter-training him -- however is this the humane thing to do for a cat who has lived outdoors for pretty much all his life?
Edit: He's not a stray -- I'm fairly sure he was born in the neighbourhood. Also, it took quite a while for him to warm up to me and allow me to pet him.