redirect_guess_404_permalink(): string|false

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

string|false

The correct URL if one is found. False on failure.

Performance profile

How much work a call to redirect_guess_404_permalink() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via ->get_var().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

8–158

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 207.

Plugin surface

3 hooks

Third-party callbacks on 'do_redirect_guess_404_permalink', 'pre_redirect_guess_404_permalink', 'strict_redirect_guess_404_permalink' run inside this call, and their cost is not bounded by anything here.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly
• sqldatabase query->get_var()called directly
• querycontent queryget_post()one call below redirect_guess_404_permalink()
• optionoption read or writeget_option()one call below redirect_guess_404_permalink()

Further down the call graph this can also reach cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 199 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost redirect_guess_404_permalink() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 3

3 hooks fire while redirect_guess_404_permalink() runs, in this order:

1. 1
   apply_filters( do_redirect_guess_404_permalink )filterline 940 (+14 into the body)

   Filters whether to attempt to guess a redirect URL for a 404 request.

2. 2
   apply_filters( pre_redirect_guess_404_permalink )filterline 955 (+29 into the body)

   Short-circuits the redirect URL guessing for 404 requests.

3. 3
   apply_filters( strict_redirect_guess_404_permalink )filterline 973 (+47 into the body)

   Filters whether to perform a strict guess for a 404 redirect.

Uses · 9

• apply_filters()Calls the callback functions that have been added to a filter hook.
• get_query_var()Retrieves the value of a query variable in the WP_Query class.
• get_post_stati()Gets a list of post statuses.
• get_post_types()Gets a list of all registered post type objects.
• esc_sql()Escapes data for use in a MySQL query.
• get_post_comments_feed_link()Retrieves the permalink for the post comments feed.
• trailingslashit()Appends a trailing slash.
• get_permalink()Retrieves the full permalink for the current post or post ID.
• user_trailingslashit()Retrieves a trailing-slashed string if the site is set for adding trailing slashes.

Used by · 1

• redirect_canonical()Redirects incoming links to the proper URL based on the site url.

Source code

View on Trac ↗View on GitHub ↗

926function redirect_guess_404_permalink() {927	global $wpdb;928 929	/**930	 * Filters whether to attempt to guess a redirect URL for a 404 request.931	 *932	 * Returning a false value from the filter will disable the URL guessing933	 * and return early without performing a redirect.934	 *935	 * @since 5.5.0936	 *937	 * @param bool $do_redirect_guess Whether to attempt to guess a redirect URL938	 *                                for a 404 request. Default true.939	 */940	if ( false === apply_filters( 'do_redirect_guess_404_permalink', true ) ) {941		return false;942	}943 944	/**945	 * Short-circuits the redirect URL guessing for 404 requests.946	 *947	 * Returning a non-null value from the filter will effectively short-circuit948	 * the URL guessing, returning the passed value instead.949	 *950	 * @since 5.5.0951	 *952	 * @param null|string|false $pre Whether to short-circuit guessing the redirect for a 404.953	 *                               Default null to continue with the URL guessing.954	 */955	$pre = apply_filters( 'pre_redirect_guess_404_permalink', null );956	if ( null !== $pre ) {957		return $pre;958	}959 960	if ( get_query_var( 'name' ) ) {961		$publicly_viewable_statuses   = array_filter( get_post_stati(), 'is_post_status_viewable' );962		$publicly_viewable_post_types = array_filter( get_post_types( array( 'exclude_from_search' => false ) ), 'is_post_type_viewable' );963 964		/**965		 * Filters whether to perform a strict guess for a 404 redirect.966		 *967		 * Returning a truthy value from the filter will redirect only exact post_name matches.968		 *969		 * @since 5.5.0970		 *971		 * @param bool $strict_guess Whether to perform a strict guess. Default false (loose guess).972		 */973		$strict_guess = apply_filters( 'strict_redirect_guess_404_permalink', false );974 975		if ( $strict_guess ) {976			$where = $wpdb->prepare( 'post_name = %s', get_query_var( 'name' ) );977		} else {978			$where = $wpdb->prepare( 'post_name LIKE %s', $wpdb->esc_like( get_query_var( 'name' ) ) . '%' );979		}980 981		// If any of post_type, year, monthnum, or day are set, use them to refine the query.982		if ( get_query_var( 'post_type' ) ) {983			if ( is_array( get_query_var( 'post_type' ) ) ) {984				$post_types = array_intersect( get_query_var( 'post_type' ), $publicly_viewable_post_types );985				if ( empty( $post_types ) ) {986					return false;987				}988				$where .= " AND post_type IN ('" . join( "', '", esc_sql( $post_types ) ) . "')";989			} else {990				if ( ! in_array( get_query_var( 'post_type' ), $publicly_viewable_post_types, true ) ) {991					return false;992				}993				$where .= $wpdb->prepare( ' AND post_type = %s', get_query_var( 'post_type' ) );994			}995		} else {996			$where .= " AND post_type IN ('" . implode( "', '", esc_sql( $publicly_viewable_post_types ) ) . "')";997		}998 999		if ( get_query_var( 'year' ) ) {1000			$where .= $wpdb->prepare( ' AND YEAR(post_date) = %d', get_query_var( 'year' ) );1001		}1002		if ( get_query_var( 'monthnum' ) ) {1003			$where .= $wpdb->prepare( ' AND MONTH(post_date) = %d', get_query_var( 'monthnum' ) );1004		}1005		if ( get_query_var( 'day' ) ) {

Changelog

Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

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