Generally, debugging C/CPP is either incredibly slow or tedious. Plain GDB is incredibly strong and, in principle, fast, but actually using it is horrible. CGDB, a terminal-based front-end, actually shows the fucking code, so that's a (necessary) upgrade. You still need to enter GDB commands, hence this page as a quick start.

Resources:

• CGDB specific stuff
• GDB manual

Launching the debugger:

• Simple launch: cgdb ./Path/To/Program
• Launch and start with arguments: cgdb -ex=start --args programToDebug arg2 arg3
• Attach to running process: cgdb -p 1234

Commands

An empty command repeats the previous command

CGDB:

• Normal mode (Esc): Browse code using VIM bindings
  • Toggle window layout using CTRL-w
• Insert mode (i): Enter GDB commands

Program states:

• Start but pause program: start
• Start and run program: r or run
• Continue running the program: c or continue
• Stop program: k or kill
• Stop debugging: q or quit

Stepping:

• Step into: s or step
• Step over: n or next
• Step out: fin or finish
• Until after some point within the current frame: u [file:]123 or until [file:]123
• Until some point: adv [file:]123 or advance [file:]123

Breakpoints:

• Set "normal" Breakpoint: b [file:]123 or break [file:]123
• Set breakpoints on function entry: b [function]
• Set conditional Breakpoint: b [file:]123 if x >= 5
• List: i b or info break
• Disable: dis 3 or disable 3
• Enable: en 3 or enable 3
• Delete: d 3 or delete 3

"Watchpoints":

• Set memory access Breakpoint: aw EXPRESSION or awatch EXPRESSION
• Set memory read Breakpoint: rw EXPRESSION or rwatch EXPRESSION
• Set memory change Breakpoint: wa EXPRESSION or watch EXPRESSION
• NOTE: For raw memory addresses: aw *0x0000beef
• List: i w or info w
• Disables/Enable/Delete like breakpoints

Frames:

• Show current frame: f or frame
• Show whole callstack: bt or backtrace
• Change current frame: f digit

Threads:

• Overview: info threads
• Change the current thread: thread [thread number]
• Issue an command to another thread: thread apply [thread number] command
• List the backtrace for all threads: thread appl all bt

Printing values:

• Simple: p EXPRESSION or print EXPRESSION
• With specific format: p/FMT ...
  • Octal: p/o
  • Hex: p/x
  • Decimal: p/d
  • Unsigned: p/u
  • Binary: p/t
  • Float: p/f
  • Instruction: p/i
  • Character: p/c
  • String: p/s
• Print array: p EXPRESSION@COUNT
• Call existing function for printing special types: call [NameOfFunction]([ARG1], ...)

Reload files using lo or load.

Configuration

To remove the copyright dump on startup, edit/create the file ~/.config/gdb/gdbearlyinit and add the line:

set startup-quietly on

To make gdb settings persistent, edit/create the file ~/.config/gdb/gdbinit. Here is my current config:

set print pretty on
set pagination off
set confirm off
set history size 1000
set history save on
set history filename ~/.config/gdb/history
set disassembly-flavor intel