wget http://fishros.com/install -O fishros && . fishros

步骤1：创建并编译工作空间
//
mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/src
catkin_init_workspace
cd ~/catkin_ws/
catkin_make
source ~/catkin_ws/devel/setup.bash     #设置环境变量
echo $ROS_PACKAGE_PATH                  #检查环境变量是否正确；正确的形式：（/home/root1/catkin_ws/src:/opt/ros/noetic/share）
//
步骤2：创建并编译功能包
//
cd ~/catkin_ws/src
catkin_create_pkg turtle_circle rospy std_msgs geometry_msgs   #创建功能包
cd ~/catkin_ws
catkin_make
source ~/catkin_ws/devel/setup.bash
//
步骤3：创建脚本文件draw_circle.py。

cd ~/catkin_ws/src/turtle_circle
mkdir scripts
cd scripts
touch draw_circle.py      
gedit draw_circle.py  #编译画圆代码处
chmod +x draw_circle.py

步骤4：运行节点
首先启动 turtlesim_node
然后运行你的 draw_circle 节点

source ~/catkin_ws/devel/setup.bash
roscore & rosrun turtlesim turtlesim_node
rosrun turtle_circle draw_circle.py
结束
补充2：
cd ~/catkin_ws/src
source ~/catkin_ws/devel/setup.bash

拓展：打开新的命令框
添加乌龟：rosservice call /spawn 3 3 0 turtle2
模仿上只运动：rosrun turtlesim mimic input:=turtle1 output:=turtle2
改变初始位置：rosservice call /turtle1/teleport_absolute 1 1 0