Command line boolean parameters to ros node

I'm working with ROS melodic and Gazebo 9.9.0 on an Ubuntu 18.04.2 LTS.

I want to get two boolean parameters from command line. To do it, I have this code:

int main(int argc, char **argv)
{
bool doDiagonalSteps = false;

bool checkDiagonalCornerUnBlocked = false;
/**
* We must call one of the versions of ros::init() before using any other
* part of the ROS system.
*/
ros::init(argc, argv, "astar_controller");

/**
* NodeHandle is the main access point to communications with the ROS system.
*/
ros::NodeHandle n;

/**
* Get parameters (if there are parameters to get.)
*/
if (!n.getParam("diagonalSteps", doDiagonalSteps))
doDiagonalSteps = false;
else
{
std::cout << "Diagonal steps: " <<  std::endl;
}

if (!n.getParam("checkDiagonalStepCorner", checkDiagonalCornerUnBlocked))
checkDiagonalCornerUnBlocked = false;
else
{
std::cout << "Diagonal Corner: " << checkDiagonalCornerUnBlocked << std::endl;
}


When I run this command on terminal:

rosrun nav_astar_nodes astar_controller _diagonalSteps:=true _checkDiagonalStepCorner:=false


I don't get anything on the output.

How can I get a boolean parameter from command line?

• and BTW: you can use nh.param<bool>("diagonalSteps", doDiagonalSteps, false); to use a default parameter. (wiki.ros.org/roscpp/Overview/…) Jul 29, 2019 at 7:15

ros::NodeHandle n("~");

Then the call to n.getParam("diagonalSteps", doDiagonalSteps) will look for the parameter in the namespace /astar_controller (the name of your node) where it was set when you passed an under-scored variable to it from the command line, instead of the global namespace which is what happens by default.