How do I convert arabic letters in htmlentities symbols?

Question

I need convert arabic letters in htmlentities symbols. Codepage: ISO-8859-1.

سك - this is arabic symbol for example.

htmlentities("سك")

returns:

س� 

How can I get from this symbol the html-entities سك?

Answer 1

htmlentities() can do only characters that have named entities. See this question on how to convert arbitrary characters into numeric entities.