03. Create a Catkin Workspace

Create a Catkin Workspace

Step 1: Create a catkin workspace and a sub directory

All of the ROS-related code you develop throughout this course will reside in your catkin workspace. You only need to create and initialize the workspace once.

First, create the top level catkin workspace directory and a sub-directory named src (pronounced source). The top level directory name is arbitrary, but is often called catkin_ws (an abbreviation of catkin_workspace), so we will follow this convention. You can create these two directories in /home/workspace/ with a single command: 

$ mkdir -p /home/workspace/catkin_ws/src

Step 2: Navigate to the source directory

Next, navigate to the src directory with the cd command: 

$ cd /home/workspace/catkin_ws/src

Step 3: Initialize the catkin workspace

Now you can initialize the catkin workspace which will create a CMakeLists.txt file: 

$ catkin_init_workspace

Let’s list the contents of the current directory to see what changed. 

$ ls -l

Notice that a symbolic link ( CMakeLists.txt ) has been created to /opt/ros/kinetic/share/catkin/cmake/toplevel.cmake

Step 4: Return to top level directory

Return to the catkin_ws, 

$ cd /home/workspace/catkin_ws

Step 5: Build the Workspace 

$ catkin_make

Note : you must issue this command from within the top level directory (i.e., within catkin_ws NOT catkin_ws/src )

While it is not essential that you have a deep understanding of the catkin build system, particularly if you are doing most of your development work in Python, it is helpful to learn about it. We encourage you to read the ROS wiki .

After the command is executed you will notice the output of the build processes being echoed to your display. When it has finished you should see the following lines at the end of the output: 

-- BUILD_SHARED_LIBS is on
-- Configuring done
-- Generating done
-- Build files have been written to: /home/workspace/catkin_ws/build
####
#### Running command: "make -j4 -l4" in "/home/workspace/catkin_ws/build"
####

But what else has changed? Use the ls command again to see what is new. 

$ ls

You now have two new directories: build and devel . The aptly named build directory is the build space for C++ packages and, for the most part, you will not interact with it. The devel directory does contain something of interest, a file named setup.bash . This setup.bash script must be sourced before using the catkin workspace with source devel/setup.bash

Step 6: Commentary

Congratulations! You just created your first catkin workspace.

Optional

Before you begin to work with and develop your own ROS package, you can take a moment to get acquainted with catkin workspace conventional directory structure as described in the ROS Enhancement Proposal (REP) 128 by clicking here .

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