ROS_Begin

1. Turtlesim Try

rospack find turtlesim

Begin

roscore
rosrun turtlesim turtlesim_node
rosrun turtlesim turtle_teleop_key
//The three commands must be in three shells.

2. Create a workspace

echo $ROS_PACKAGE_PATH

mkdir -p ~/dev/catkin_ws/src
cd ~/dev/catkin_ws/src
catkin_init_workspace

cd ~/dev/catkin_ws
catkin_make

source devel/setup.bash     
//在新终端下无法定位功能包时，可运行此命令解决，因此可将此命令写入.bashrc中彻底解决问题。

3. Create a package and build it

cd ~/dev/catkin_ws/src
catkin_create_pkg tutorials std_msgs roscpp
//catkin_create_pkg [package_name] [depend1] [depend2] [depend...]

cd ~/dev/catkin_ws
catkin_make     //build all
//catkin_make tutorials //build tutorials only