GDB init file (~/.gdbinit) auto-loads on startup. Use it to set options, define commands, and configure debugging defaults.

# ~/.gdbinit
set print pretty on              # pretty-print structures
set pagination off               # no paging (useful for scripts)
set print address off            # hide memory addresses in output
set confirm off                  # no confirmation prompts
set history save on              # save command history
set history size 10000           # keep 10k commands in history
break main                       # set breakpoint at startup
directory /path/to/sources       # add source path
define mycommand                 # define custom command
  print x
  print y
  backtrace
end

set print pretty on formats structures with indentation, making them easier to read. Especially useful for nested structures or large arrays.

set pagination off disables paging—GDB no longer stops output with -- more -- prompts. Useful when running GDB in scripts or remote sessions.

set print address off hides memory addresses in output. Makes output cleaner when addresses are not needed for debugging.

set confirm off removes confirmation prompts (e.g., “Really delete all breakpoints?”). Useful for automation, but risk losing data if you accidentally delete something.

directory adds source search paths. GDB uses these to find source files for display. If GDB can't find main.c, add directory /path/to/project.

define creates custom commands. Define reusable debugging sequences. Commands defined in ~/.gdbinit are available at every GDB session. Define debugging shortcuts for your project (e.g., dumpstate might print key variables and backtrace).

History saves your commands across sessions. history size controls how many to keep (default 256). Useful for recalling previous debugging sessions.

Create ~/.gdbinit for your preferred settings. Start fresh sessions with your configuration automatically loaded.