This function is the Hello World example from the AWS Greengrass Core C SDK. It also contains the rest of the C examples from that repo so it can be reconfigured to run any of those functions.
The build script in this directory uses Docker to build the AWS C++ SDK and the example functions. Even on a fast machine this may take hours the first time the build runs.
Some systems do not run the Resin.io cross-build container properly. Docker will print an error message like this when cross-builds are not possible:
standard_init_linux.go:207: exec user process caused "exec format error"
If the Docker host is ARM32 it should work without an issue.
If this function is launched successfully then you should expect to see the message hello world! on the hello/world topic every few seconds.