To execute the code(linux)

Important- Sourcing the setup file in all terminals which you use directory_To_workspace/catkin_ws/devel/setup.bash.

-> Install ROS (http://wiki.ros.org/kinetic/Installation) --> Either you can create your own catkin_ws and follow

--> Else clone the whole workspace from git

create catkin workspace following http://wiki.ros.org/catkin/Tutorials/create_a_workspace
create ros pakage http://wiki.ros.org/ROS/Tutorials/CreatingPackage add std_msgs rospy roscpp as dependencies.
download all cpp file from https://github.com/karannaoh/catkin_ws/tree/master/src/intern_task/src and mv them to workspace/src/pakage_you_created/scr
download file form
download https://github.com/karannaoh/catkin_ws/blob/master/intern_task/launch/intern_task.launch in folder workspace/pakage_name/launch
in workspace catkin_make
then roslaunch pakage_name inten_task.launcher

note:-