we are going to learn today the basics of ROS so open up your terminal and uh here we have 2
already installed the ROS but let me check ROS2 topic list ROS2 command not found so this system 3
does not know where the ROS2 actually is so we will have to Source out terminal in order to let 4
the system know that here is the ROS type source opt ROS foxy setup dot bash okay so now I 5
will try the same command again this time it gives me topics but for if I open up another 6
terminal and type ros2 topic list oh again the command not found so if we have to use the ROS we 7
will have to source the ROS setup first but in order to avoid it we can do one more thing 8
echo source opt Ros foxy setup dot bash 9
bashrc it will insert this line into the bashrc just close this terminal and 10
open a new terminal ros2 topic list now we have the topics no we do not need to 11
source ROS2 every time in a new terminal you can also do it manually you 12
can go to the file press control H or show the hidden file uh there you go bashrc and 13
in the end you will see this is added you can simply close it press contrl h so in order to 14
check your verion of ros and the ros distro you can choose a Command this is the Command where you can 15
check the Ross variable distro and the version here you can see the ROS version is two 16
python version is three and a bunch of other detail that you do not need to 17
know right now that was the all about environment 18
setup