In Scent of a Woman, there is a scene where Colonel Slade is preparing for his suicide and has a conversation with Charlie. He asks this question: "Should I adopt you or shoot you?"
What is he adopting? Charlie's conscious?
You need to look at the entire conversation to understand it:
As we know, Frank Slade is a short tempered alcoholic, whose is also blind and medically retired. He's not happy. He's on one last trip to enjoy himself, before killing himself. Charlie meets him by taking a temporary job to look after him to earn some money. Charlie is only a student, compared to the old, retired man.
This is one of these stories about understanding the good of life and how every day can bring hope and a new adventure. Charlie is so naivé in the world, so good inside compared to the bitter, cynical nature of Slade.
Charlie realises Slade is going to kill himself and rushes back to the hotel to save him. Charlie states how he really was fooled and thought Slade had gotten rid of the bullets from the gun. Slade can't believe how young and foolish he can be (which is why he asks him how he'll survive without him).
When Slade says he'll shoot him, he refers to the fact he and George are going to "sing like a canary". If you remember, this is a reference to the start of the film:
Slade is effectively telling him that once he accepts the bribe, he's going to be like everybody else. Nothing special, nothing good. Ruined.
Charlie tries to be firm with him to turn the situation around and when that only appears to aggravate the situation, he apologises - despite being the one with a gun pointed at him.
It's at this moment Slade mentions the line you quoted. What he means is that he respects Charlie a lot. Part of Charlie frustrates him beyond belief - the naivé little boy who can be fooled so easily ("whether to shoot you"), and another part of him respects this incredible kid, who'll stand up for what he believes for no reason other than because he feels he has to ("adopt you").
He's showing his conflicting emotions, that's all. Part of him is frustrated, but a larger part (which we see in the remainder of the movie) is moved by Charlie's integrity and strength of character - so much so, that Slade unexpectedly passionately defends him at the disciplinary committee and appears at the end of the film to turn his own life around based on his experiences with Charlie.