When working with Robot Operating System (ROS), you will often create packages to organize your code and make it easy to share with others. These packages can contain multiple nodes, libraries, and other resources. However, to build and use a ROS package, you need to create two important files:

• CMakeLists.txt

• package.xml

Also Read: ROS parameters

In this blog post, we will explore what these files are, why they are created automatically in a ROS package, and how important they are to a ROS package.

What is CMakeLists.txt?

CMakeLists.txt is a text file used by the CMake build system to configure, build, and install software. In ROS, CMakeLists.txt is used to specify the dependencies, compiler flags, and build rules for a package.

CMakeLists.txt is created automatically in a new ROS package, and it is an important file because it defines how your package is built and linked to other packages. For example, you can use CMakeLists.txt to specify that your package depends on another package, and CMake will automatically find and include that package in the build process.

What is package.xml?

package.xml is an XML file used to describe the metadata of a ROS package, including its name, version, dependencies, and maintainer information. It is also created automatically in a new ROS package.

The package.xml file is important because it provides important information about your package, such as its dependencies, that other ROS tools and users can use to find and use your package. For example, the ROS package manager, apt-get, use the package.xml file to resolve package dependencies and install packages.

Why are CMakeLists.txt and package.xml files important in a ROS package?

CMakeLists.txt and package.xml files are essential to a ROS package because they define how your package is built, linked, and distributed. By specifying the dependencies, compiler flags, and build rules in CMakeLists.txt, you can ensure that your package is built correctly and can link to other packages. Similarly, by including metadata such as dependencies and maintainer information in the package.xml file, you can make it easy for other users and tools to find and use your package.

Additionally, the CMakeLists.txt and package.xml files are used by other ROS tools, such as roscd and rospack, to locate and manage packages. Without these files, your package may not be recognized or built correctly, making it difficult to use and share with others.

Conclusion

In conclusion, CMakeLists.txt and package.xml files are automatically created in a new ROS package and are essential to building, linking, and distributing a ROS package. By understanding how to use these files effectively, you can ensure that your package is built and linked correctly and can be easily shared and used by others in the ROS community.