The first step is to create an empty workspace folder and another folder called src to store the ROS package in. The following command will do this job. The workspace folder name here is catkin_ws.

$ mkdir -p ~/catkin_ws/src

Switch to the src folder and execute the catkin_init_workspace command. This command will initialize a catkin workspace in the current src folder. We can now start creating packages inside the src folder.

$ cd ~/catkin_ws/src
$ catkin_init_workspace

After initializing the catkin workspace, we can build the packages inside the workspace using the following command, catkin_make. We can build the workspace even without any packages.

$ cd ~/catkin_ws/
$ catkin_make

This will create additional folders called build and devel inside the ROS workspace:

Figure 19: The catkin workspace folders

Once you've built the workspace, in order to access packages inside the workspace we should add the workspace environment to our .bashrc file using the following command:

$ echo "source ~/catkin_ws/devel/setup.bash" >> 
      ~/.bashrc
$ source ~/.bashrc

If everything is done, you can verify it by executing the following command. This command will print the entire ROS package path. If your workspace path is in the output, you are done!

$ echo $ROS_PACKAGE_PATH

Figure 20: The ROS package path