load program

Load the program into the target.

b main

Set a breakpoint in function main.

c

Continue after a breakpoint.

l

View a listing of the program.

n

Step one line (stepping over function calls).

s

Step one line (stepping into function calls).

info reg

View register values.

p xyz

Print the value of xyz data.

watch gvar1

Set Watchpoint on Global Variable gvar1.

via Commonly Used GDB Console Commands