GDB and CGDB Cheat Sheet

GDB (GNU Debugger)

GDB is a powerful tool for debugging applications written in C, C++, and other languages. Here’s a quick reference to some commonly used commands:

Basic Commands

  • gdb [program] - Start GDB with the specified program.
  • run [args] - Run the program with optional arguments.
  • break [location] - Set a breakpoint at the specified location (function, line number, etc.).
  • continue - Continue execution until the next breakpoint.
  • next - Execute the next line of the program (step over).
  • step - Step into a function.
  • list - Show the source code around the current line.
  • print [expression] - Evaluate and print the expression.
  • info breakpoints - List all breakpoints.
  • delete breakpoints [number] - Delete a specific breakpoint.
  • quit - Exit GDB.

Advanced Commands

  • watch [var] - Set a watchpoint for a variable.
  • backtrace - Show the call stack.
  • frame [number] - Select a frame from the call stack.
  • set variable [var]=[value] - Set a variable to a new value.
  • disassemble [function] - Show assembly code for the function.
  • catch [event] - Break on specific events like throw or catch.

CGDB (Curses-based interface to the GNU Debugger)

CGDB provides a more user-friendly interface to GDB. It includes split views showing source code and GDB commands simultaneously.

Key Bindings

  • F7 - Step into a function (step in GDB).
  • F8 - Step over a function (next in GDB).
  • F9 - Set or clear a breakpoint at the current line.
  • F10 - Continue program execution (continue in GDB).
  • Ctrl + L - Redraw the screen.
  • Tab - Switch between source and GDB command window.

Using CGDB

  • Launching: cgdb [program]
  • In the source window, you can navigate the code just like in a text editor.
  • In the GDB command window, you can type any GDB command.

Tips for CGDB

  • CGDB remembers the history of GDB commands; use the arrow keys to navigate through past commands.
  • The split screen allows simultaneous viewing of source code and real-time debugging output, enhancing the debugging experience.
This post is licensed under CC BY 4.0 by the author.