you should be aware of a feature that
allows users to turn on UTF support from within a pattern, provided that PCRE
was built with UTF support. For example, an 8-bit pattern that begins with
"(*UTF8)" or "(*UTF)" turns on UTF-8 mode, which interprets patterns and
subjects as strings of UTF-8 characters instead of individual 8-bit characters.
This causes both the pattern and any data against which it is matched to be
checked for UTF-8 validity. If the data string is very long, such a check might
use sufficie