ode from either
<b>pcre2_regcomp()</b> or <b>pcre2_regexec()</b> to a printable message. If
<i>preg</i> is not NULL, the error should have arisen from the use of that
structure. A message terminated by a binary zero is placed in <i>errbuf</i>. If
the buffer is too short, only the first <i>errbuf_size</i> - 1 characters of the
error message are used. The yield of the function is the size of buffer needed
to hold the whole message, including the terminating zero. This value is
greater than <i>errbuf_size</i> 