demo.mov
GEP
(GDB Enhanced Prompt) is a GDB plug-in which make your GDB command prompt more convenient and flexibility.
GDB's original prompt is using hardcoded built-in GNU readline library, we can't add our custom function and key binding easily. The old way to implement them is by patching the GDB's C source code and compiling it again.
But now, you can write your function in Python and use arbitrary key binding easily with GEP without any patching!
And also, GEP has some awesome features already, you can directly use it!
- Ctrl+r for fzf history reverse search
- ↑ key for partial string matching in history
- TAB for auto-completion with:
- fzf (When fzf is installed)
- floating window (Similar to IPython's auto-completion)
- fish-like autosuggestions (→ key to accept the suggestion)
- has the ability to build custom key binding and its callback function by modifying
geprc.py
- compatible with the latest version of your favorite GDB plug-ins:
Make sure you have GDB 8.0+ (ideally GDB 14.1+ for the best experience) and compiled with Python3.8+ bindings, then:
- Install git
- Make sure you have virtualenv installed
- Install fzf: Installation (Optional, but GEP works better with fzf)
- Install this plug-in by:
# You could also choose other directories to install GEP if you want
git clone --depth 1 https://github.com/lebr0nli/GEP.git ~/.local/share/GEP
~/.local/share/GEP/install.sh
- Enjoy!
Important
After the installation, the script will automatically add source /path/to/GEP/gdbinit-gep.py
to your ~/.gdbinit
file. Please make sure this line is always at the end of your ~/.gdbinit
file during future modifications of your ~/.gdbinit
to avoid some unexpected behaviors.
If your ~/.gdbinit
is something like this: source ~/.local/share/GEP/gdbinit-gep.py
, then you can update GEP by:
cd ~/.local/share/GEP && git pull && ./install.sh
You can modify the configuration for history, auto-completion, and other GEP configurations in /path/to/GEP/gdbinit-gep
.
You can also add your custom key bindings by modifying /path/to/GEP/geprc.py
.
Note
The example subdirectory houses samples and default configurations.
Since GDB doesn't have a good Python API to fully control and emulate its prompt, this plug-in has some side effects.
However, the side effects are avoidable, here are the guides to avoid them:
Somehow, GEP breaks the TUI mode in GDB, so it's advisable not to use GDB's built-in TUI when working with GEP (refer to issue #13).
Instead of using gdb TUI, I personally recommend trying pwndbg/pwndbg, hugsy/gef and cyrus-and/gdb-dashboard to enhance your debugging experience.
If you have any ideas to resolve this issue, PRs are greatly appreciated. 🙏
The GDB Python API event: gdb.event.before_prompt
may be called only once.
So if you are using a GDB plug-in that is listening on this event, this plug-in will cause some bugs.
Note
pwndbg, gef, and gdb-dashboard won't be affected by this side effect so far, but please open an issue if you find any plug-in that is affected by this side effect.
To avoid this, you can change the callback function by adding them to gdb.prompt_hook
, gdb.prompt_hook
has almost
the same effects with event.before_prompt
, but gdb.prompt_hook
can be directed invoke, so this plug-in still can
emulate that callback for you!
When your input is empty and directly press ENTER, GDB will execute the previous command from history if that command
doesn't have the property: dont-repeat
.
As far as I know, there is no GDB API for checking a command's property.
So, I added some commonly used commands (for original GDB API and GEF) which have that property in a set to avoid repeatedly executing them.
If you have some user-defined function that has dont-repeat
property, add your command into the set manually, too.
Note
The set of those user-defined commands are in geprc.py
and the variable name for it is DONT_REPEAT
.
If you found some builtin commands which should or shouldn't be added by default, let me know on the issue page, thanks!
If this is your current ~/.gdbinit
file after the installation:
source /path/to/GEP/gdbinit-gep.py
Then, you can uninstall this plug-in by:
rm -rf /path/to/GEP
And remove source /path/to/GEP/gdbinit-gep.py
from your ~/.gdbinit
.
Some ideas/code are inspired by hugsy/gef and pwndbg/pwndbg.
Thanks!
If you found any bug, or you have any suggestions/ideas about this plug-in, feel free to leave your feedback on the GitHub issue page or send me a pull request!
Thanks!