vncdotool is a command line VNC client.

It comes in handy when automating interactions with virtual machines or some hardware devices that are otherwise difficult to control.

Currently under development, so use at your own peril but what is the worst that could happen?

Quick Start

To see vncdotool in action you can run it against an existing VNC server or start one locally with x11vnc. Then you can run:

pip install twisted # if you don't already have it
python vncdotool/ -s hostaddr type "hello world"

If you have PIL installed then you can do a screen captures with:

python vncdotool/ -s hostaddr capture screen.png


vncdotool depends on Twisted. Additionally, for capture and expect commands to work you will need the Python Image Library. You can use your favourite package manager to grab them. Once you have the dependencies installed you install from the unpacked source tree.

python install


Once installed you can use the vncdotool command to send key-presses. Alphanumerics are straightforward just specify the character. For other keys longer names are used:

vncdotool key a
vncdotool key 5
vncdotool key .
vncdotool key enter
vncdotool key shift-a
vncdotool key ctrl-C
vncdotool key ctrl-alt-del

To type longer strings when entering data or commands you can use the type c command, which does not support special characters:

vncdotool type "hello world"

You can control the mouse pointer with move and click commands:

vncdotool move 100 100
vncdotool click 1

If you have the Python Imaging Library (PIL) installed you can also make screen captures of the session:

vncdotool capture screenshot.png

Again if you have PIL, you can wait for the screen to match a known image.:

vncdotool expect somescreen.png 0

Finally, you may specify multiple actions on a single command line:

vncdotool type username key enter expect password_prompt.png
vncdotool type password move 100 150 click 1 expect welcome_screen.png


Comments, suggestions and patches are welcome and appreciated. They can be sent to or via


Thanks to Chris Liechti, techtonik and Todd Whiteman for developing the RFB and DES implementations used by vncdotool.

_python-vnc-viewer: _Twisted: _PIL: