Send Twist message on Ctrl.+C

edit

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

I want to send a "stop" message to the robot when user kills a node.

To handle Ctrl.+C event, I use this:

/**
 * Override the default ros sigint handler to stop the robot when user press
 * Ctrl.+C.
 */
void sigintHandler(int sig)
{


  // All the default sigint handler does is call shutdown()
  ros::shutdown();
}

But this function doesn't allow to pass more parameters (I need to pass topic publisher, ros::Publisher cmd_vel_pub, to send the "stop" command).

I have declared this publisher on main function:

int main(int argc, char **argv)
{
  ros::init(argc, argv, "astar_controller");

  ros::NodeHandle n;

  // Override the default ros sigint handler.
  // This must be set after the first NodeHandle is created.
  std::signal(SIGINT, sigintHandler);

  /**
   * Topic where we are going to publish speed commands.
   */
  ros::Publisher cmd_vel_pub = n.advertise<geometry_msgs::Twist>(cmdTopic, 1000);

  // More code...
}

What is the best option to get access to cmd_vel_pub?

I've thought to declared as global, but I don't think is a good option.