re provided for backwards compatibility with
earlier versions of PCRE2, which had only POSIX names. However, this has proved
troublesome in situations where a program links with several libraries, some of
which use PCRE2's POSIX interface while others use the real POSIX functions.
For this reason, the POSIX names have been removed since release 10.37.
</p>
<p>
Calling the header file <b>pcre2posix.h</b> avoids any conflict with other POSIX
libraries. It can, of course, be renamed or aliased as <b>regex.h</b