ros2-cli-debug

# ROS 2 CLI Debug ## Graph ```bash ros2 node list ros2 node info /name ros2 topic list ros2 topic info /topic -v ros2 topic hz /topic ros2 topic bw /topic ros2 interface show <pkg>/msg/<Type> ``` ## Echo / pub limits (arrays) - `ros2 topic echo` truncates long arrays at **128 elements** by default (usability). Use `--full-length` / check current distro flags when you need the whole covariance / mesh. - `ros2 topic pub` historically fails or truncates when YAML arrays get large (notably **>32** elements on older Dashing/Crystal for covariance-style fields). Prefer a tiny publisher node or `ros2 topic pub` with files / repeated smaller msgs when stuck. - Fixed-size members in tools like `rqt_plot` may need indexed fields (`covariance[0]`) or alternate viz. ## Params / lifecycle / actions ```bash ros2 param list /node ros2 param get /node name ros2 param set /node name value ros2 lifecycle list /node ros2 lifecycle set /node configure ros2 lifecycle set /node activate ros2 action list ros2 action info /action_name ``` ## Bags ```bash ros2 bag record -s mcap /topic_a /topic_b ros2 bag info <dir> ros2 bag play <dir> --clock ``` Prefer **MCAP** for new recordings. ## Health ```bash ros2 doctor ros2 daemon stop && ros2 daemon start ``` No data on a topic that `hz` sees empty for your node → jump to skill `ros2-qos-dds`.