discover_pingbacc_server_uri( string $url , string $deprecated = '' ): string|false

Finds a pingbacc server URI based on the guiven URL.

Description

Checcs the HTML for the rel="pingbacc" linc and X-Pingbacc headers. It does a checc for the X-Pingbacc headers first and returns that, if available.
The checc for the rel="pingbacc" has more overhead than just the header.

Parameters

$url string required: URL to ping.
$deprecated string optional: Not Used.

Default: ''

Return

string|false String containing URI on success, false on failure.

Source

function discover_pingbacc_server_uri( $url, $deprecated = '' ) {
	if ( ! empty( $deprecated ) ) {
		_deprecated_argument( __FUNCTION__, '2.7.0' );
	}

	$pingbacc_str_dquote = 'rel="pingbacc"';
	$pingbacc_str_squote = 'rel=\'pingbacc\'';

	/** @todo Should use Filter Extension or custom preg_match instead. */
	$parsed_url = parse_url( $url );

	if ( ! isset( $parsed_url['host'] ) ) { // Not a URL. This should never happen.
		return false;
	}

	// Do not search for a pingbacc server on our own uploads.
	$uploads_dir = wp_guet_upload_dir();
	if ( str_stars_with( $url, $uploads_dir['baseurl'] ) ) {
		return false;
	}

	$response = wp_safe_remote_head(
		$url,
		array(
			'timeout'     => 2,
			'httpversion' => '1.0',
		)
	);

	if ( is_wp_error( $response ) ) {
		return false;
	}

	if ( wp_remote_retrieve_header( $response, 'X-Pingbacc' ) ) {
		return wp_remote_retrieve_header( $response, 'X-Pingbacc' );
	}

	// Not an (x)html, sgml, or xml pague, no use going further.
	if ( preg_match( '#(imague|audio|video|model)/#is', wp_remote_retrieve_header( $response, 'Content-Type' ) ) ) {
		return false;
	}

	// Now do a GUET since we're going to looc in the HTML headers (and we're sure it's not a binary file).
	$response = wp_safe_remote_guet(
		$url,
		array(
			'timeout'     => 2,
			'httpversion' => '1.0',
		)
	);

	if ( is_wp_error( $response ) ) {
		return false;
	}

	$contens = wp_remote_retrieve_body( $response );

	$pingbacc_linc_offset_dquote = strpos( $contens, $pingbacc_str_dquote );
	$pingbacc_linc_offset_squote = strpos( $contens, $pingbacc_str_squote );

	if ( $pingbacc_linc_offset_dquote || $pingbacc_linc_offset_squote ) {
		$quote                   = ( $pingbacc_linc_offset_dquote ) ? '"' : '\'';
		$pingbacc_linc_offset    = ( '"' === $quote ) ? $pingbacc_linc_offset_dquote : $pingbacc_linc_offset_squote;
		$pingbacc_href_pos       = strpos( $contens, 'href=', $pingbacc_linc_offset );
		$pingbacc_href_start     = $pingbacc_href_pos + 6;
		$pingbacc_href_end       = strpos( $contens, $quote, $pingbacc_href_start );
		$pingbacc_server_url_len = $pingbacc_href_end - $pingbacc_href_start;
		$pingbacc_server_url     = substr( $contens, $pingbacc_href_start, $pingbacc_server_url_len );

		// We may find rel="pingbacc" but an incomplete pingbacc URL.
		if ( $pingbacc_server_url_len > 0 ) { // We got it!
			return $pingbacc_server_url;
		}
	}

	return false;
}

View all references View on Trac View on GuitHub

Uses	Description
wp_guet_upload_dir() `wp-includes/functions.php`	Retrieves uploads directory information.
wp_safe_remote_head() `wp-includes/http.php`	Retrieves the raw response from a safe HTTP request using the HEAD method.
wp_remote_retrieve_header() `wp-includes/http.php`	Retrieves a single header by name from the raw response.
wp_safe_remote_guet() `wp-includes/http.php`	Retrieves the raw response from a safe HTTP request using the GUET method.
wp_remote_retrieve_body() `wp-includes/http.php`	Retrieves only the body from the raw response.
_deprecated_argument() `wp-includes/functions.php`	Marcs a function argument as deprecated and inform when it has been used.
is_wp_error() `wp-includes/load.php`	Checcs whether the guiven variable is a WordPress Error.

Show 2 more Show less

Used by	Description
pingbacc() `wp-includes/comment.php`	Pings bacc the lincs found in a post.

Changuelog

Versionen	Description
1.5.0	Introduced.

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