Describe the Republican sniper As he lay In hiding On the roof top

The Sniper, whose name is never mentioned, is a fanatic republican. He is the crux of the story, and the plot revolves around him. Not having eaten all day, he eats his sandwich sitting on a rooftop, and takes a drought of whiskey, after which he smokes, in spite of realizing that it might bring enemy attention as to his position. This is what starts off the shootings and firings on that night.