function phutil_is_utf8_slowly($string, $only_bmp)
libphutil Technical Documentation (Core Utilities)

Determine if a string is valid UTF-8, slowly.

This works on any system, but has very poor performance.

You should call phutil_is_utf8() instead of this function, as that function can use more performant mechanisms if they are available on the system.

Parameters

string	$string	Some string which may or may not be valid UTF-8.
bool	$only_bmp	True to require all characters be part of the basic multilingual plane (no more than 3-bytes long).

Return

bool	True if the string is valid UTF-8.

function phutil_is_utf8_slowly($string, $only_bmp)libphutil Technical Documentation (Core Utilities)