added ServeEvent.InstallerFunc field

tools/osutils/cmd.go

@@ -0,0 +1,31 @@
+package osutils
+
+import (
+	"os/exec"
+	"runtime"
+
+	"github.com/go-ozzo/ozzo-validation/v4/is"
+)
+
+// LaunchURL attempts to open the provided url in the user's default browser.
+//
+// It is platform dependent and it uses:
+//   - "open" on macOS
+//   - "rundll32" on Windows
+//   - "xdg-open" on everything else (Linux, FreeBSD, etc.)
+func LaunchURL(url string) error {
+	if err := is.URL.Validate(url); err != nil {
+		return err
+	}
+
+	switch runtime.GOOS {
+	case "darwin":
+		return exec.Command("open", url).Start()
+	case "windows":
+		// not sure if this is the best command but seems to be the most reliable based on the comments in
+		// https://stackoverflow.com/questions/3739327/launching-a-website-via-the-windows-commandline#answer-49115945
+		return exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
+	default:
+		return exec.Command("xdg-open", url).Start()
+	}
+}