Refactored and reorganized code

internal/util/util.go

@@ -5,6 +5,8 @@ import (
 	"math/rand"
 	"net/url"
 	"os"
+	"os/exec"
+	"runtime"
 	"strings"
 )
 
@@ -58,3 +60,22 @@ func PathExists(path string) (bool, error) {
 	}
 	return false, err
 }
+
+// https://stackoverflow.com/questions/39320371/how-start-web-server-to-open-page-in-browser-in-golang
+// open opens the specified URL in the default browser of the user.
+func OpenUrl(url string) error {
+	var cmd string
+	var args []string
+
+	switch runtime.GOOS {
+	case "windows":
+		cmd = "cmd"
+		args = []string{"/c", "start"}
+	case "darwin":
+		cmd = "open"
+	default: // "linux", "freebsd", "openbsd", "netbsd"
+		cmd = "xdg-open"
+	}
+	args = append(args, url)
+	return exec.Command(cmd, args...).Start()
+}