ntent A string which might contain a URL. * @return string The found URL. */ function get_url_in_content( $content ) { if ( empty( $content ) ) { return false; } if ( preg_match( '/]*?href=([\'"])(.+?)\1/is', $content, $matches ) ) { return esc_url_raw( $matches[2] ); } return false; } /** * Returns the regexp for common whitespace characters. * * By default, spaces include new lines, tabs, nbsp entities, and the UTF-8 nbsp. * This is designed to replace the PCRE \s sequence. In ticket #22692, that * sequence was found to be unreliable due to random inclusion of the A0 byte. * * @since 4.0.0 * * @return string The spaces regexp. */ function wp_spaces_regexp() { static $spaces; if ( empty( $spaces ) ) { /** * Filter the regexp for common whitespace characters. * * This string is substituted for the \s sequence as needed in regular * expressions. For websites not written in English, different characters * may represent whitespace. For websites not encoded in UTF-8, the 0xC2 0xA0 * sequence may not be in use. * * @since 4.0.0 * * @param string $spaces Regexp pattern for matching common whitespace characters. */ $spaces = apply_filters( 'wp_spaces_regexp', '[\r\n\t ]|\xC2\xA0| ' ); } return $spaces; }