What is the ruling on whistling in order to call someone?

A Muslim must treat his brothers with good manners and call his companion by the name most beloved to him. As for whistling to alert someone with whom you have no affection, some scholars have disliked it. One must address a person who is not like that with the best address, so that he does not think you despise him, for Satan is keen to sow enmity among people, as Almighty Allah says: "Satan only wants to cause animosity and hatred between you" (Al-Ma'idah: 91).