PCRE, Perl-compatible regular expression, library has its own native API, but
a set of wrapper functions that are based on the POSIX API are also supplied
in the libpcreposix library. Note that this just provides a POSIX calling
interface to PCRE: the regular expressions themselves still follow Perl syntax
and semantics. This package provides support for strings in 8-bit and UTF-8
encodings. Detailed change log is provided by pcre-doc package.