When the folder name created by php contains the word '黑', the word '黑' is more likely to appear repeatedly. What is the reason?

Reply content:

BLACK

• GB18030: FC5C
• UTF-8: E9 BB 92
• UTF-16: 9ED2

Know that 5C is in ASCII What does it represent? The special symbol ''!
In the printf function of C language, it is an escape character. A bug in PHP prevents it from handling this correctly and causes the string to be truncated
The solution is to either file a bug or simply not use GB18030 Encoding using Unicode across the board I have encountered this word in python before, and it bugged me

But I am in php7.0.6 (PHP 7.0.6 (cli) (built: Apr 28 2016 14:11:34) (NTS)) Tested 10 times each with 5.6.7 (PHP 5.6.7 (cli) (built: Mar 19 2015 15:09:32)), the problem did not occur. The system is server2012R2, and the latest patch has been applied.