How to start a ros node

edit

You can either use rosrun or manually execute the binary/script. In the first case, run:

rosrun <package_name> <executable_name>

In the second case look up the executable name (if you're using catking, it's usually in

<catkin_workspace>/devel/lib/<executable_name>

EDIT

I see what you want to do now! If you want the nodelet manager (that's the node you're looking for), then you should look at manager.launch.xml in rgbd_launch. In particular the lines that you're interested in are:

<!-- Nodelet manager -->
  <node pkg="nodelet" type="nodelet" name="$(arg name)" args="manager"
        output="screen" launch-prefix="$(arg launch_prefix)">
     <param name="num_worker_threads" value="$(arg num_worker_threads)" />
  </node>

where the name is set in the calling launch file (openni.launch, https://github.com/ros-drivers/openni... ).

Just remember that all roslaunch does is to call processes, so if roslaunch can do it then you can do it as well at the command line! For example if you want to run the nodelet above, just type:

>> rosrun nodelet nodelet manager _num_worker_threads:=4