Examine execution stack and variables

• 'bt' shows you the execution stack (innermost function first).
• 'up' and 'down' move between stack frames, to allow examining their contents
• ...(but does NOT move the instruction pointer - i.e. 'next' will continue in the inner-most frame).
• 'frame <number>' moves to the given frame ('bt' shows frame numbers').
• 'frame' to see the current stack frame.
• 'print <expression>' evaluates an expression.
• ... In particular, use it to view contents of variables.
• ... Will look for local variables in the current stack frame.

Originally written by guy keren