Useful snippets for ROS

Set CMake options in `catkin build`

To pass CMake options to the catkin build tool simply use the --cmake-args command line switch. For example to set the CMAKE_BUILD_TYPE I would use:

catkin build --cmake-args -DCMAKE_BUILD_TYPE=Debug

To save the so that they are added for every call you can use the --save-config command line option :

catkin build --save-CONFIG --cmake-args -DCMAKE_BUILD_TYPE=Debug

Build a single package

To build a single package just specify its name at after catkin build, e.g.

catkin build my_package

There is also an even more convenient form. If you are in the package directory then you can simply use

catkin build --this

To just re-build the package without touching any of its dependencies use:

catkin build --this --no-deps

The --this switch can also, quite conveniently, be used for catkin clean.

Create a new package

To create a new ROS package with all the boilerplate just use:

catkin create pkg PACKAGE_NAME

Most of the options of the package.xml file can also be set from the command line.

-l	Add licence
-a	Add author in "First Name, Last Name" email format
-m	Add maintainer

An example invocation using all of these parameters is:

catkin create pkg demo -l MIT -a "Thibaud Chupin" thibaud.chupin@mail.com

Change the console log format

The default format string for logs in ROS is quite poor. I usually want to know what node produced each message for example. Changing it is quite simple fortunately, we just need to override the ROSCONSOLE_FORMAT shell variable. The format string I use now is:

export ROSCONSOLE_FORMAT='[${severity}] <${time}> ${node} @ ${file}:${line}
    ${message}'

Note the new line! This produces logs that have the following appearance.

[ INFO] <1494230701.053693261> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:26
    Listening for camera images on /lappycam/image_rect_color
[ INFO] <1494230701.060647944> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:43
    Publishing camera pose to /lappycam/pose
[ INFO] <1494230701.063317878> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:49
    Publishing detection images on /lappycam/detections
[ INFO] <1494230701.356161276> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:55
    Publishing detected marker poses and ids on /lappycam/markers
[ INFO] <1494230701.357764129> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:59
    Aruco board detector ready.
[ INFO] <1494230701.362489914> /camera_left_extrinsic @ /home/me/Projects/Nearlab/ros_ws/src/aruco_extrinsic/src/ArucoBoardDetector.cpp:66
    Aruco board parameters: size = 6x4, length = 0.0222, sep = 0.004, dictionary = 1

The full list of variables that can be used in the ROS console format string cane be found in the documentation.

Debugging a node launched with `rosrun`

To run gdb on a node launched with rosrun simply add --prefix 'gdb -ex run' to the command line. This will start gdb and run the node.

A complete invocation might look something like this:

rosrun --prefix 'gdb -ex run' my_pkg my_node

Debugging a node launched with `roslaunch`

With roslaunch we don't control the command line like when we start the node with rosrun instead we can pass gdb command with the prefix parameter in the <node> declaration.

<node pkg="my_pkg" type="my_node" name="node" prefix="gb -ex run">
</node>

Check out the documentation for node to see the full list of parameters it accepts.

Set CMake options in catkin build