The ROS2CD Tool

The journey of writing a quick cd tool for ros2 packages.

If you use ROS (Robot Operating System) long enough, you would know the command line tool roscd. And once you start using ROS2, I am sure you would notice that the equivalent command is not available.

There are multiple reasons why there is not a ros2cd tool. One of the reasons, is that ROS2 no longer have the concept of devel space for a workspace, hence, after the installation of the packages, we have no correlation of the source space anymore. Therefore, the only possible location to switch to would be the install space which is not what we developers wants.

If you dig deeper, you would find the colcon_cd tool. Unfortunately, this tool is written by someone how has never used roscd. So to close this bridge, let’s dive into a simple solution for ros2cd, it is by no means perfect, but hopefully a starting point where others could built on top and be helpful to those who are used to roscd coming from ROS1.

Thought Process

At the moment, tab completion feature is not available, it is only a simple script to quickly bring the user to their developing packages. I am also utilizing the fzf tool to allow the user to fuzzy search through the available packages with zsh. Of course, bash users can use it without any issue.

1. Obtain the path to the packages from the environment variables
2. Loop through the paths and save it to trimmed_workspaces variable if it contains the install keyword
3. To ensure that the path is a ROS2 package, we will filter the obtained paths by checking whether package.xml file exist
4. Prompt users to choose with fzf to fuzzy search through the available packages
5. Lastly, jump to the selected directory

Try Out!

The tool is currently on GitHub, please feel free to try it out! Suggestions and pull request are welcome!

curl -s https://raw.githubusercontent.com/BruceChanJianLe/ros2cd/refs/heads/master/install.sh | bash

Future Work

One thing that could actually be worked on is to cache the results of the local packages, instead of looking it up every single invoke of ros2cd. Latency can be observed with large workspaces that has a lot of packages.

Surely, tab completion could also be something nice. Well below are some references that I found useful for readings about zsh tab completion:

• https://mrigank11.github.io/2018/03/zsh-auto-completion/
• https://caelis.medium.com/create-basic-zsh-command-with-auto-completion-cc069f971ba8
• https://github.com/zsh-users/zsh-completions/blob/master/zsh-completions-howto.org