simple gdb commands

i thr     Print information about all threads.
bt        Print backtrace.
f <num>   Just to stack frame <num> in current thread backtrace.
p <sym>   Print information about symbol <sym>.
i locals  Print information about local variables in current stack frame.
h         gdb help.
c         Continue execution.
s         Step to next line of code. Steps into functions.
n         Step to next line of code. Does not step into functions.