Each function is for a different operating system.
GOOS=windows go run main.go
## Mac (Darwin)
GOOS=darwin go run main.go
GOOS=linux go run main.go
Each function makes use of the filename suffix e.g. _linux.go instead of using // go:build linux commentary
More examples: https://www.jetbrains.com/help/go/configuring-build-constraints-and-vendoring.html#build-constraints