In which film is Mark Watney a character?

Who played Sean Maguire in 'Good Will Hunting'? In which film is Sean Maguire a character? Who played Jason Bourne in 'The Bourne Identity'? Who played Mark Watney in 'The Martian'? Who played John Keating in 'Dead Poets Society'? In which film is John Keating a character? Who played Adrian Cronauer in 'Good Morning, Vietnam'? Who played Agent J in 'Men in Black'?