How to check the real number of the other party when you receive a text message quietly?

If there is an illegal act, it can be found. If it is a joke between friends, it can't be found.

If I disturb you and affect your normal life, it is a violation of the Law on Public Security Administration Punishment. The parties can report the case to the public security organ, and the public security department will conduct a real-name investigation.

Detained for less than 5 days or fined for less than 500 yuan; If the circumstances are serious, they shall be detained for more than 5 days 10 days, and may also be fined up to 500 yuan.