Describe pips encounter in the cemetery

Pip visits the cemetary. He is suddenly terrified by the voice of large, bedraggled man who threatens to cut Pip's throat if he doesn't stop crying.The man, dressed in a prison uniform with a great iron shackle around his leg, grabs the boy and shakes him upside down, emptying his pockets. The man devours a piece of bread which falls from the boy, then barks questions at him. Pip tells him that yes, he is an orphan and that he lives with his sister, Mrs. Joe Gargery, the wife of a blacksmith, about a mile from the church. The man tells Pip that if he wants to live, he'll go down to his house and bring him back some food and a file for the shackle on his leg. Pip agrees to meet him early the next morning and the man walks back into the marshes.

In great expectations what two ways does pip help the convict