htaccess Elite

// Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference" by Mark Jaquith

Code: Select all

function redirect_canonical($requested_url=NULL, $do_redirect=true) {
   global $wp_rewrite, $posts, $is_IIS;

   if ( is_feed() || is_trackback() || is_search() || is_comments_popup() || is_admin() || $is_IIS || ( isset($_POST) && count($_POST) ) )
      return;

   if ( !$requested_url ) {
      // build the URL in the address bar
      $requested_url  = ( isset($_SERVER['HTTPS'] ) && strtolower($_SERVER['HTTPS']) == 'on' ) ? 'https://' : 'http://';
      $requested_url .= $_SERVER['HTTP_HOST'];
      $requested_url .= $_SERVER['REQUEST_URI'];
   }

   $original = @parse_url($requested_url);
   if ( false === $original )
      return;

   // Some PHP setups turn requests for / into /index.php in REQUEST_URI
   $original['path'] = preg_replace('|/index\.php$|', '/', $original['path']);

   $redirect = $original;
   $redirect_url = false;

   // These tests give us a WP-generated permalink
   if ( is_404() ) {
      $redirect_url = redirect_guess_404_permalink();
   } elseif ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() ) {
      // rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101
      if ( is_single() && isset($_GET['p']) ) {
         if ( $redirect_url = get_permalink(get_query_var('p')) )
            $redirect['query'] = remove_query_arg('p', $redirect['query']);
      } elseif ( is_page() && isset($_GET['page_id']) ) {
         if ( $redirect_url = get_permalink(get_query_var('page_id')) )
            $redirect['query'] = remove_query_arg('page_id', $redirect['query']);
      } elseif ( isset($_GET['m']) && ( is_year() || is_month() || is_day() ) ) {
         $m = get_query_var('m');
         switch ( strlen($m) ) {
            case 4: // Yearly
               $redirect_url = get_year_link($m);
               break;
            case 6: // Monthly
               $redirect_url = get_month_link( substr($m, 0, 4), substr($m, 4, 2) );
               break;
            case 8: // Daily
               $redirect_url = get_day_link(substr($m, 0, 4), substr($m, 4, 2), substr($m, 6, 2));
               break;
         }
         if ( $redirect_url )
            $redirect['query'] = remove_query_arg('m', $redirect['query']);
      // now moving on to non ?m=X year/month/day links
      } elseif ( is_day() && get_query_var('year') && get_query_var('monthnum') && isset($_GET['day']) ) {
         if ( $redirect_url = get_day_link(get_query_var('year'), get_query_var('monthnum'), get_query_var('day')) )
            $redirect['query'] = remove_query_arg(array('year', 'monthnum', 'day'), $redirect['query']);
      } elseif ( is_month() && get_query_var('year') && isset($_GET['monthnum']) ) {
         if ( $redirect_url = get_month_link(get_query_var('year'), get_query_var('monthnum')) )
            $redirect['query'] = remove_query_arg(array('year', 'monthnum'), $redirect['query']);
      } elseif ( is_year() && isset($_GET['year']) ) {
         if ( $redirect_url = get_year_link(get_query_var('year')) )
            $redirect['query'] = remove_query_arg('year', $redirect['query']);
      } elseif ( is_category() && isset($_GET['cat']) ) {
         if ( $redirect_url = get_category_link(get_query_var('cat')) )
            $redirect['query'] = remove_query_arg('cat', $redirect['query']);
      } elseif ( is_author() && isset($_GET['author']) ) {
         $author = get_userdata(get_query_var('author'));
         if ( false !== $author && $redirect_url = get_author_link(false, $author->ID, $author->user_nicename) )
            $redirect['query'] = remove_query_arg('author', $redirect['author']);
      }

   // paging
      if ( $paged = get_query_var('paged') ) {
         if ( $paged > 0 ) {
            if ( !$redirect_url )
               $redirect_url = $requested_url;
            $paged_redirect = @parse_url($redirect_url);
            $paged_redirect['path'] = preg_replace('|/page/[0-9]+?(/+)?$|', '/', $paged_redirect['path']); // strip off any existing paging
            $paged_redirect['path'] = preg_replace('|/index.php/?$|', '/', $paged_redirect['path']); // strip off trailing /index.php/
            if ( $paged > 1 && !is_single() ) {
               $paged_redirect['path'] = trailingslashit($paged_redirect['path']);
               if ( $wp_rewrite->using_index_permalinks() && strpos($paged_redirect['path'], '/index.php/') === false )
                  $paged_redirect['path'] .= 'index.php/';
               $paged_redirect['path'] .= user_trailingslashit("page/$paged", 'paged');
            } elseif ( !is_home() && !is_single() ){
               $paged_redirect['path'] = user_trailingslashit($paged_redirect['path'], 'paged');
            }
            $redirect_url = $paged_redirect['scheme'] . '://' . $paged_redirect['host'] . $paged_redirect['path'];
            $redirect['path'] = $paged_redirect['path'];
         }
         $redirect['query'] = remove_query_arg('paged', $redirect['query']);
      }
   }

   // tack on any additional query vars
   if ( $redirect_url && $redirect['query'] ) {
      if ( strpos($redirect_url, '?') !== false )
         $redirect_url .= '&';
      else
         $redirect_url .= '?';
      $redirect_url .= $redirect['query'];
   }

   if ( $redirect_url )
      $redirect = @parse_url($redirect_url);

   // www.example.com vs example.com
   $user_home = @parse_url(get_option('home'));
   $redirect['host'] = $user_home['host'];

   // Handle ports
   if ( isset($user_home['port']) )
      $redirect['port'] = $user_home['port'];
   else
      unset($redirect['port']);

   // trailing /index.php/
   $redirect['path'] = preg_replace('|/index.php/$|', '/', $redirect['path']);

   // strip /index.php/ when we're not using PATHINFO permalinks
   if ( !$wp_rewrite->using_index_permalinks() )
      $redirect['path'] = str_replace('/index.php/', '/', $redirect['path']);

   // trailing slashes
   if ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() && !is_404() && (!is_home() || ( is_home() && (get_query_var('paged') > 1) ) ) ) {
      $user_ts_type = '';
      if ( get_query_var('paged') > 0 ) {
         $user_ts_type = 'paged';
      } else {
         foreach ( array('single', 'category', 'page', 'day', 'month', 'year') as $type ) {
            $func = 'is_' . $type;
            if ( call_user_func($func) )
               $user_ts_type = $type;
               break;
            }
         }
      $redirect['path'] = user_trailingslashit($redirect['path'], $user_ts_type);
   } elseif ( is_home() ) {
      $redirect['path'] = trailingslashit($redirect['path']);
   }

   // Always trailing slash the 'home' URL
   if ( $redirect['path'] == $user_home['path'] )
      $redirect['path'] = trailingslashit($redirect['path']);

   // Ignore differences in host capitalization, as this can lead to infinite redirects
   if ( strtolower($original['host']) == strtolower($redirect['host']) )
      $redirect['host'] = $original['host'];

   if ( array($original['host'], $original['port'], $original['path'], $original['query']) !== array($redirect['host'], $redirect['port'], $redirect['path'], $redirect['query']) ) {
      $redirect_url = $redirect['scheme'] . '://' . $redirect['host'];
      if ( isset($redirect['port']) )
          $redirect_url .= ':' . $redirect['port'];
      $redirect_url .= $redirect['path'];
      if ( $redirect['query'] )
         $redirect_url .= '?' . $redirect['query'];
   }

   if ( $redirect_url && $redirect_url != $requested_url ) {
      // var_dump($redirect_url); die();
      $redirect_url = apply_filters('redirect_canonical', $redirect_url, $requested_url);
      if ( $do_redirect) {
         // protect against chained redirects
         if ( !redirect_canonical($redirect_url, false) ) {
            wp_redirect($redirect_url, 301);
            exit();
         } else {
            return false;
         }
      } else {
         return $redirect_url;
      }
   } else {
      return false;
   }
}

Code: Select all

function redirect_guess_404_permalink() {
   global $wp_query, $wpdb;
   if ( !get_query_var('name') )
      return false;

   $where = "post_name LIKE '" . $wpdb->escape(get_query_var('name')) . "%'";

   // if any of year, monthnum, or day are set, use them to refine the query
   if ( get_query_var('year') )
      $where .= " AND YEAR(post_date) = '" . $wpdb->escape(get_query_var('year')) . "'";
   if ( get_query_var('monthnum') )
      $where .= " AND MONTH(post_date) = '" . $wpdb->escape(get_query_var('monthnum')) . "'";
   if ( get_query_var('day') )
      $where .= " AND DAYOFMONTH(post_date) = '" . $wpdb->escape(get_query_var('day')) . "'";

   $post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE $where AND post_status = 'publish'");
   if ( !$post_id )
      return false;
   return get_permalink($post_id);
}

add_action('template_redirect', 'redirect_canonical');

[quote]Canonical URLs is one of the features that I worked on for WordPress 2.3 It’s sort of a geeky concept, but the end result has benefits that a non-geek can appreciate, so I’m going to break it down for you.

WordPress has traditionally been very lenient in the URLs that it will accept.

For instance, say your blog is hosted on http://www.example.com/blog/.

You can likely access the front page of your blog via these alternative URLs:

* http://example.com/blog/
* http://www.example.com/blog/index.php/
* http://example.com/blog/index.php/
* http://www.example.com/blog/?paged=1
* http://example.com/blog/?paged=1
* http://www.example.com/blog/page/1/
* http://example.com/blog/page/1/

And those are just the “saneâ€