s no way to stop newline from matching [^a].
</p>
<p>
Default POSIX newline handling can be obtained by setting PCRE2_DOTALL and
PCRE2_DOLLAR_ENDONLY when calling <b>pcre2_compile()</b> directly, but there is
no way to make PCRE2 behave exactly as for the REG_NEWLINE action. When using
the POSIX API, passing REG_NEWLINE to PCRE2's <b>pcre2_regcomp()</b> function
causes PCRE2_MULTILINE to be passed to <b>pcre2_compile()</b>, and REG_DOTALL
passes PCRE2_DOTALL. There is no way to pass PCRE2_DOLLAR_ENDONLY.
</