Exploring the frequently used commands

CMake offers many, many scripting commands that allow you to work with variables and the environment. Some of them have been extensively covered in the Appendix section, for example: list(), string() and file(). Others, such as find_file(), find_package(), find_path() fit better in chapters that talk about their respective subjects. In this section, we will provide a brief overview of the common commands that are useful in most situations:

• message()
• include()
• include_guard()
• file()
• execute_process()

Let’s get to it.

The message() command

We already know and love our trusty message() command, which prints text to standard output. However, there's a lot more to it than meets the eye. By providing a MODE argument, you can customize the behavior of the command like so: message(<MODE> "text to print").

The recognized modes are as follows:

• FATAL_ERROR: This stops processing and generation.
• SEND_ERROR: This continues processing...