WordPress/wp-blog-header.php

<?php

if (! isset($wp_did_header)):
if ( !file_exists( dirname(__FILE__) . '/wp-config.php') ) {
	if ( strstr( $_SERVER['PHP_SELF'], 'wp-admin') ) $path = '';
	else $path = 'wp-admin/';
    die("There doesn't seem to be a <code>wp-config.php</code> file. I need this before we can get started. Need more help? <a href='http://wordpress.org/docs/faq/#wp-config'>We got it</a>. You can <a href='{$path}setup-config.php'>create a <code>wp-config.php</code> file through a web interface</a>, but this doesn't work for all server setups. The safest way is to manually create the file.");
}

$wp_did_header = true;

require_once( dirname(__FILE__) . '/wp-config.php');

$query_vars = array();

// Process PATH_INFO and 404.
if ((isset($_GET['error']) && $_GET['error'] == '404') ||
		((! empty($_SERVER['PATH_INFO'])) &&
		('/' != $_SERVER['PATH_INFO']) &&
		 (false === strpos($_SERVER['PATH_INFO'], 'index.php'))
		)) {

	// If we match a rewrite rule, this will be cleared.
	$error = '404';

	// Fetch the rewrite rules.
	$rewrite = $wp_rewrite->wp_rewrite_rules();

	if (! empty($rewrite)) {
		$pathinfo = $_SERVER['PATH_INFO'];
		$req_uri = $_SERVER['REQUEST_URI'];      
		$home_path = parse_url(get_settings('home'));
		$home_path = $home_path['path'];

		// Trim path info from the end and the leading home path from the
		// front.  For path info requests, this leaves us with the requesting
		// filename, if any.  For 404 requests, this leaves us with the
		// requested permalink.	
		$req_uri = str_replace($pathinfo, '', $req_uri);
		$req_uri = str_replace($home_path, '', $req_uri);
		$req_uri = trim($req_uri, '/');
		$pathinfo = trim($pathinfo, '/');

		// The requested permalink is in $pathinfo for path info requests and
		//  $req_uri for other requests.
		if (! empty($pathinfo)) {
			$request = $pathinfo;
		} else {
			$request = $req_uri;
		}

		// Look for matches.
		$request_match = $request;
		foreach ($rewrite as $match => $query) {
			// If the requesting file is the anchor of the match, prepend it
			// to the path info.
	    if ((! empty($req_uri)) && (strpos($match, $req_uri) === 0)) {
	      $request_match = $req_uri . '/' . $request;
	    }

			if (preg_match("!^$match!", $request_match, $matches)) {
				// Got a match.
				// Trim the query of everything up to the '?'.
				$query = preg_replace("!^.+\?!", '', $query);

				// Substitute the substring matches into the query.
				eval("\$query = \"$query\";");

				// Parse the query.
				parse_str($query, $query_vars);

				// If we're processing a 404 request, clear the error var
				// since we found something.
				if (isset($_GET['error'])) {
					unset($_GET['error']);
				}

				if (isset($error)) {
					unset($error);
				}

				break;
			}
		}
	}
 }

$wpvarstoreset = array('m','p','posts','w', 'cat','withcomments','s','search','exact', 'sentence','preview','debug', 'calendar','page','paged','more','tb', 'pb','author','order','orderby', 'year', 'monthnum', 'day', 'hour', 'minute', 'second', 'name', 'category_name', 'feed', 'author_name', 'static', 'pagename', 'page_id', 'error');

$wpvarstoreset = apply_filters('query_vars', $wpvarstoreset);

for ($i=0; $i<count($wpvarstoreset); $i += 1) {
	$wpvar = $wpvarstoreset[$i];
	if (!isset($$wpvar)) {
		if (empty($_POST[$wpvar])) {
			if (empty($_GET[$wpvar]) && empty($query_vars[$wpvar])) {
				$$wpvar = '';
			} elseif (!empty($_GET[$wpvar])) {
				$$wpvar = $_GET[$wpvar];
			} else {
				$$wpvar = $query_vars[$wpvar];
			}
		} else {
			$$wpvar = $_POST[$wpvar];
		}
	}
}

// Sending HTTP headers

if ( !empty($error) && '404' == $error ) {
	header('HTTP/1.x 404 Not Found');
 } else if ( empty($feed) ) {
	@header('X-Pingback: '. get_bloginfo('pingback_url'));
} else {
	// We're showing a feed, so WP is indeed the only thing that last changed
	if ( $withcomments )
		$wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastcommentmodified('GMT'), 0).' GMT';
	else 
		$wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
	$wp_etag = '"' . md5($wp_last_modified) . '"';
	@header("Last-Modified: $wp_last_modified");
	@header("ETag: $wp_etag");
	@header('X-Pingback: ' . get_bloginfo('pingback_url'));

	// Support for Conditional GET
	if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) $client_last_modified = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
	else $client_last_modified = false;
	if (isset($_SERVER['HTTP_IF_NONE_MATCH'])) $client_etag = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
	else $client_etag = false;

	if ( ($client_last_modified && $client_etag) ?
	    (($client_last_modified == $wp_last_modified) && ($client_etag == $wp_etag)) :
	    (($client_last_modified == $wp_last_modified) || ($client_etag == $wp_etag)) ) {
		if ( preg_match('/cgi/',php_sapi_name()) ) {
		    header('HTTP/1.1 304 Not Modified');
		    echo "\r\n\r\n";
		    exit;
		} else {
		    if ( version_compare(phpversion(), '4.3.0', '>=') ) {
		        header('Not Modified', TRUE, 304);
		    } else {
		        header('HTTP/1.x 304 Not Modified');
		    }
			exit;
		}
	}
}

$use_gzipcompression = get_settings('gzipcompression');

$more_wpvars = array('posts_per_page', 'posts_per_archive_page', 'what_to_show', 'showposts', 'nopaging');

// Construct the query string.
$query_string = '';
foreach (array_merge($wpvarstoreset, $more_wpvars) as $wpvar) {
	if ($$wpvar != '') {
		$query_string .= (strlen($query_string) < 1) ? '' : '&';
		$query_string .= $wpvar . '=' . rawurlencode($$wpvar);
	}
}

$query_string = apply_filters('query_string', $query_string);

update_category_cache();

// Call query posts to do the work.
$posts = query_posts($query_string);

// Extract updated query vars back into global namespace.
extract($wp_query->query_vars);

if (1 == count($posts)) {
	$more = 1;
	$single = 1;
}

// Issue a 404 if a permalink request doesn't match any posts.  Don't issue a
// 404 if one was already issued, if the request was a search, or if the
// request was a regular query string request rather than a permalink request.
if ( (0 == count($posts)) && !is_404() && !is_search()
		 && !empty($_SERVER['QUERY_STRING']) &&
		 (false === strpos($_SERVER['REQUEST_URI'], '?')) ) {
	$wp_query->is_404 = true;
	header('HTTP/1.x 404 Not Found');
}

// Template redirection
if ( defined('WP_USE_THEMES') && constant('WP_USE_THEMES') ) {
	do_action('template_redirect');
	if ( is_feed() && empty($doing_rss) ) {
		include(ABSPATH . '/wp-feed.php');
		exit;
	} else if ( is_trackback() && empty($doing_trackback) ) {
		include(ABSPATH . '/wp-trackback.php');
		exit;
	} else if ( is_404() && get_404_template() ) {
		include(get_404_template());
		exit;
	} else if ( is_search() && get_search_template() ) {
		include(get_search_template());
		exit;
	} else if ( is_home() && get_home_template() ) {
		include(get_home_template());
		exit;
	} else if ( is_single() && get_single_template() ) {
		include(get_single_template());
		exit;
	} else if ( is_page() && get_page_template() ) {
		include(get_page_template());
		exit;
	} else if ( is_category() && get_category_template()) {
		include(get_category_template());
		exit;		
	} else if ( is_author() && get_author_template() ) {
		include(get_author_template());
		exit;
	} else if ( is_date() && get_date_template() ) {
		include(get_date_template());
		exit;
	} else if ( is_archive() && get_archive_template() ) {
		include(get_archive_template());
		exit;
	} else if ( is_paged() && get_paged_template() ) {
		include(get_paged_template());
		exit;
	} else if ( file_exists(TEMPLATEPATH . "/index.php") ) {
		include(TEMPLATEPATH . "/index.php");
		exit;
	}
} else {
	// Process feeds and trackbacks even if not using themes.
	if ( is_feed() && empty($doing_rss) ) {
		include(ABSPATH . '/wp-feed.php');
		exit;
	} else if ( is_trackback() && empty($doing_trackback) ) {
		include(ABSPATH . '/wp-trackback.php');
		exit;
	}
}

if ($pagenow != 'post.php' && $pagenow != 'edit.php') {
	if ( get_settings('gzipcompression') ) 
		gzip_compression();
}

endif;
?>