Helpful GDB Plugins:
PEDA
PEDA – Python Exploit Development Assistance for GDB
https://github.com/longld/peda
GEF
GDB Enhanced Features
https://github.com/hugsy/gef Lisa.py
LLDB
Lisa.py: An Exploit Dev Swiss Army Knife.
https://github.com/ant4g0nist/lisa.py
Voltron
Voltron is an extensible debugger UI toolkit written in Python.
https://github.com/snare/voltron
How to use GDB debug:
http://heather.cs.ucdavis.edu/~matloff/UnixAndC/CLanguage/Debug.html