GDB Hex Display

I always forget how useful that is, so writing it here:

x (for "examine") examines memory in several formats

x/nfu addr
x addr
x

n, f, and u are optional parameters that specify how much memory to display and how to format it;
addr is an expression where to start displaying memory. 

n, the repeat count
Decimal integer; the default is 1. It specifies how much memory (counting by units u) to display.

f, the display format
One of the formats used by print, 's' (null-terminated string), or 'i' (machine instruction). The default is 'x' (hexadecimal) initially. The default changes each time you use either x or print.

u, the unit size
The unit size is any of
    b - bytes.
    h - half words (two bytes).
   w - words (four bytes). This is the initial default.
   g - giant words (eight bytes).

e.g.

x/20xb