/wp-includes/ms-functions.php

<?php

/**

 * Multi-site WordPress API

 *

 * @package WordPress

 * @subpackage Multisite

 * @since 3.0.0

 */



/**

 * Gets the network's site and user counts.

 *

 * @since MU 1.0

 * @uses get_blog_count()

 * @uses get_user_count()

 *

 * @return array Site and user count for the network.

 */

function get_sitestats() {

	global $wpdb;



	$stats['blogs'] = get_blog_count();

	$stats['users'] = get_user_count();



	return $stats;

}



/**

 * Get the admin for a domain/path combination.

 *

 * @since MU 1.0

 *

 * @param string $sitedomain Optional. Site domain.

 * @param string $path Optional. Site path.

 * @return array The network admins

 */

function get_admin_users_for_domain( $sitedomain = '', $path = '' ) {

	global $wpdb;



	if ( ! $sitedomain )

		$site_id = $wpdb->siteid;

	else

		$site_id = $wpdb->get_var( $wpdb->prepare( "SELECT id FROM $wpdb->site WHERE domain = %s AND path = %s", $sitedomain, $path ) );



	if ( $site_id )

		return $wpdb->get_results( $wpdb->prepare( "SELECT u.ID, u.user_login, u.user_pass FROM $wpdb->users AS u, $wpdb->sitemeta AS sm WHERE sm.meta_key = 'admin_user_id' AND u.ID = sm.meta_value AND sm.site_id = %d", $site_id ), ARRAY_A );



	return false;

}



/**

 * Get one of a user's active blogs

 *

 * Returns the user's primary blog, if she has one and

 * it is active. If it's inactive, function returns another

 * active blog of the user. If none are found, the user

 * is added as a Subscriber to the Dashboard Blog and that blog

 * is returned.

 *

 * @since MU 1.0

 * @uses get_blogs_of_user()

 * @uses add_user_to_blog()

 * @uses get_blog_details()

 *

 * @param int $user_id The unique ID of the user

 * @return object The blog object

 */

function get_active_blog_for_user( $user_id ) {

	global $wpdb;

	$blogs = get_blogs_of_user( $user_id );

	if ( empty( $blogs ) )

		return null;



	if ( !is_multisite() )

		return $blogs[$wpdb->blogid];



	$primary_blog = get_user_meta( $user_id, 'primary_blog', true );

	$first_blog = current($blogs);

	if ( false !== $primary_blog ) {

		if ( ! isset( $blogs[ $primary_blog ] ) ) {

			update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );

			$primary = $first_blog;

		} else {

			$primary = get_blog_details( $primary_blog );

		}

	} else {

		//TODO Review this call to add_user_to_blog too - to get here the user must have a role on this blog?

		add_user_to_blog( $first_blog->userblog_id, $user_id, 'subscriber' );

		update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );

		$primary = $first_blog;

	}



	if ( ( ! is_object( $primary ) ) || ( is_object( $primary ) && $primary->archived == 1 || $primary->spam == 1 || $primary->deleted == 1 ) ) {

		$blogs = get_blogs_of_user( $user_id, true ); // if a user's primary blog is shut down, check their other blogs.

		$ret = false;

		if ( is_array( $blogs ) && count( $blogs ) > 0 ) {

			foreach ( (array) $blogs as $blog_id => $blog ) {

				if ( $blog->site_id != $wpdb->siteid )

					continue;

				$details = get_blog_details( $blog_id );

				if ( is_object( $details ) && $details->archived == 0 && $details->spam == 0 && $details->deleted == 0 ) {

					$ret = $blog;

					if ( get_user_meta( $user_id , 'primary_blog', true ) != $blog_id )

						update_user_meta( $user_id, 'primary_blog', $blog_id );

					if ( !get_user_meta($user_id , 'source_domain', true) )

						update_user_meta( $user_id, 'source_domain', $blog->domain );

					break;

				}

			}

		} else {

			return null;

		}

		return $ret;

	} else {

		return $primary;

	}

}



/**

 * Find out whether a user is a member of a given blog.

 *

 * @since MU 1.1

 * @uses get_blogs_of_user()

 *

 * @param int $user_id The unique ID of the user

 * @param int $blog Optional. If no blog_id is provided, current site is used

 * @return bool

 */

function is_user_member_of_blog( $user_id, $blog_id = 0 ) {

	$user_id = (int) $user_id;

	$blog_id = (int) $blog_id;



	if ( $blog_id == 0 ) {

		global $wpdb;

		$blog_id = $wpdb->blogid;

	}



	$blogs = get_blogs_of_user( $user_id );

	if ( is_array( $blogs ) )

		return array_key_exists( $blog_id, $blogs );

	else

		return false;

}



/**

 * The number of active users in your installation.

 *

 * The count is cached and updated twice daily. This is not a live count.

 *

 * @since MU 2.7

 *

 * @return int

 */

function get_user_count() {

	return get_site_option( 'user_count' );

}



/**

 * The number of active sites on your installation.

 *

 * The count is cached and updated twice daily. This is not a live count.

 *

 * @since MU 1.0

 *

 * @param int $id Optional. A site_id.

 * @return int

 */

function get_blog_count( $id = 0 ) {

	return get_site_option( 'blog_count' );

}



/**

 * Get a blog post from any site on the network.

 *

 * @since MU 1.0

 *

 * @param int $blog_id ID of the blog.

 * @param int $post_id ID of the post you're looking for.

 * @return object The post.

 */

function get_blog_post( $blog_id, $post_id ) {

	global $wpdb;



	$key = $blog_id . '-' . $post_id;

	$post = wp_cache_get( $key, 'global-posts' );

	if ( $post == false ) {

		$post = $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM ' . $wpdb->get_blog_prefix( $blog_id ) . 'posts WHERE ID = %d', $post_id ) );

		wp_cache_add( $key, $post, 'global-posts' );

	}



	return $post;

}



/**

 * Add a user to a blog.

 *

 * Use the 'add_user_to_blog' action to fire an event when

 * users are added to a blog.

 *

 * @since MU 1.0

 *

 * @param int $blog_id ID of the blog you're adding the user to.

 * @param int $user_id ID of the user you're adding.

 * @param string $role The role you want the user to have

 * @return bool

 */

function add_user_to_blog( $blog_id, $user_id, $role ) {

	switch_to_blog($blog_id);



	$user = new WP_User($user_id);



	if ( empty( $user->ID ) ) {

		restore_current_blog();

		return new WP_Error('user_does_not_exist', __('That user does not exist.'));

	}



	if ( !get_user_meta($user_id, 'primary_blog', true) ) {

		update_user_meta($user_id, 'primary_blog', $blog_id);

		$details = get_blog_details($blog_id);

		update_user_meta($user_id, 'source_domain', $details->domain);

	}



	$user->set_role($role);



	do_action('add_user_to_blog', $user_id, $role, $blog_id);

	wp_cache_delete( $user_id, 'users' );

	restore_current_blog();

	return true;

}



/**

 * Remove a user from a blog.

 *

 * Use the 'remove_user_from_blog' action to fire an event when

 * users are removed from a blog.

 *

 * Accepts an optional $reassign parameter, if you want to

 * reassign the user's blog posts to another user upon removal.

 *

 * @since MU 1.0

 *

 * @param int $user_id ID of the user you're removing.

 * @param int $blog_id ID of the blog you're removing the user from.

 * @param string $reassign Optional. A user to whom to reassign posts.

 * @return bool

 */

function remove_user_from_blog($user_id, $blog_id = '', $reassign = '') {

	global $wpdb;

	switch_to_blog($blog_id);

	$user_id = (int) $user_id;

	do_action('remove_user_from_blog', $user_id, $blog_id);



	// If being removed from the primary blog, set a new primary if the user is assigned

	// to multiple blogs.

	$primary_blog = get_user_meta($user_id, 'primary_blog', true);

	if ( $primary_blog == $blog_id ) {

		$new_id = '';

		$new_domain = '';

		$blogs = get_blogs_of_user($user_id);

		foreach ( (array) $blogs as $blog ) {

			if ( $blog->userblog_id == $blog_id )

				continue;

			$new_id = $blog->userblog_id;

			$new_domain = $blog->domain;

			break;

		}



		update_user_meta($user_id, 'primary_blog', $new_id);

		update_user_meta($user_id, 'source_domain', $new_domain);

	}



	// wp_revoke_user($user_id);

	$user = new WP_User($user_id);

	if ( empty( $user->ID ) ) {

		restore_current_blog();

		return new WP_Error('user_does_not_exist', __('That user does not exist.'));

	}



	$user->remove_all_caps();



	$blogs = get_blogs_of_user($user_id);

	if ( count($blogs) == 0 ) {

		update_user_meta($user_id, 'primary_blog', '');

		update_user_meta($user_id, 'source_domain', '');

	}



	if ( $reassign != '' ) {

		$reassign = (int) $reassign;

		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->posts SET post_author = %d WHERE post_author = %d", $reassign, $user_id) );

		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->links SET link_owner = %d WHERE link_owner = %d", $reassign, $user_id) );

	}



	restore_current_blog();

}



/**

 * Create an empty blog.

 *

 * @since MU 1.0

 * @uses install_blog()

 *

 * @param string $domain The new blog's domain.

 * @param string $path The new blog's path.

 * @param string $string The new blog's title.

 * @param int $site Optional. Defaults to 1.

 * @return int The ID of the newly created blog

 */

function create_empty_blog( $domain, $path, $weblog_title, $site_id = 1 ) {

	$domain			= addslashes( $domain );

	$weblog_title	= addslashes( $weblog_title );



	if ( empty($path) )

		$path = '/';



	// Check if the domain has been used already. We should return an error message.

	if ( domain_exists($domain, $path, $site_id) )

		return __( 'Error: Site URL already taken.' );



	// Need to back up wpdb table names, and create a new wp_blogs entry for new blog.

	// Need to get blog_id from wp_blogs, and create new table names.

	// Must restore table names at the end of function.



	if ( ! $blog_id = insert_blog($domain, $path, $site_id) )

		return __( 'Error: problem creating site entry.' );



	switch_to_blog($blog_id);

	install_blog($blog_id);

	restore_current_blog();



	return $blog_id;

}



/**

 * Get the permalink for a post on another blog.

 *

 * @since MU 1.0

 *

 * @param int $_blog_id ID of the source blog.

 * @param int $post_id ID of the desired post.

 * @return string The post's permalink

 */

function get_blog_permalink( $_blog_id, $post_id ) {

	$key = "{$_blog_id}-{$post_id}-blog_permalink";

	$link = wp_cache_get( $key, 'site-options' );

	if ( $link == false ) {

		switch_to_blog( $_blog_id );

		$link = get_permalink( $post_id );

		restore_current_blog();

		wp_cache_add( $key, $link, 'site-options', 360 );

	}

	return $link;

}



/**

 * Get a blog's numeric ID from its URL.

 *

 * On a subdirectory installation like example.com/blog1/,

 * $domain will be the root 'example.com' and $path the

 * subdirectory '/blog1/'. With subdomains like blog1.example.com,

 * $domain is 'blog1.example.com' and $path is '/'.

 *

 * @since MU 2.6.5

 *

 * @param string $domain

 * @param string $path Optional. Not required for subdomain installations.

 * @return int

 */

function get_blog_id_from_url( $domain, $path = '/' ) {

	global $wpdb;



	$domain = strtolower( $wpdb->escape( $domain ) );

	$path = strtolower( $wpdb->escape( $path ) );

	$id = wp_cache_get( md5( $domain . $path ), 'blog-id-cache' );



	if ( $id == -1 ) { // blog does not exist

		return 0;

	} elseif ( $id ) {

		return (int)$id;

	}



	$id = $wpdb->get_var( "SELECT blog_id FROM $wpdb->blogs WHERE domain = '$domain' and path = '$path' /* get_blog_id_from_url */" );



	if ( !$id ) {

		wp_cache_set( md5( $domain . $path ), -1, 'blog-id-cache' );

		return false;

	}

	wp_cache_set( md5( $domain . $path ), $id, 'blog-id-cache' );



	return $id;

}



// Admin functions



/**

 * Redirect a user based on $_GET or $_POST arguments.

 *

 * The function looks for redirect arguments in the following order:

 * 1) $_GET['ref']

 * 2) $_POST['ref']

 * 3) $_SERVER['HTTP_REFERER']

 * 4) $_GET['redirect']

 * 5) $_POST['redirect']

 * 6) $url

 *

 * @since MU

 * @uses wpmu_admin_redirect_add_updated_param()

 *

 * @param string $url

 */

function wpmu_admin_do_redirect( $url = '' ) {

	$ref = '';

	if ( isset( $_GET['ref'] ) )

		$ref = $_GET['ref'];

	if ( isset( $_POST['ref'] ) )

		$ref = $_POST['ref'];



	if ( $ref ) {

		$ref = wpmu_admin_redirect_add_updated_param( $ref );

		wp_redirect( $ref );

		exit();

	}

	if ( empty( $_SERVER['HTTP_REFERER'] ) == false ) {

		wp_redirect( $_SERVER['HTTP_REFERER'] );

		exit();

	}



	$url = wpmu_admin_redirect_add_updated_param( $url );

	if ( isset( $_GET['redirect'] ) ) {

		if ( substr( $_GET['redirect'], 0, 2 ) == 's_' )

			$url .= '&action=blogs&s='. esc_html( substr( $_GET['redirect'], 2 ) );

	} elseif ( isset( $_POST['redirect'] ) ) {

		$url = wpmu_admin_redirect_add_updated_param( $_POST['redirect'] );

	}

	wp_redirect( $url );

	exit();

}



/**

 * Adds an 'updated=true' argument to a URL.

 *

 * @since MU

 *

 * @param string $url

 * @return string

 */

function wpmu_admin_redirect_add_updated_param( $url = '' ) {

	if ( strpos( $url, 'updated=true' ) === false ) {

		if ( strpos( $url, '?' ) === false )

			return $url . '?updated=true';

		else

			return $url . '&updated=true';

	}

	return $url;

}



/**

 * Checks an email address against a list of banned domains.

 *

 * This function checks against the Banned Email Domains list

 * at wp-admin/network/settings.php. The check is only run on

 * self-registrations; user creation at wp-admin/network/users.php

 * bypasses this check.

 *

 * @since MU

 *

 * @param string $user_email The email provided by the user at registration.

 * @return bool Returns true when the email address is banned.

 */

function is_email_address_unsafe( $user_email ) {

	$banned_names = get_site_option( 'banned_email_domains' );

	if ($banned_names && !is_array( $banned_names ))

		$banned_names = explode( "\n", $banned_names);



	if ( is_array( $banned_names ) && empty( $banned_names ) == false ) {

		$email_domain = strtolower( substr( $user_email, 1 + strpos( $user_email, '@' ) ) );

		foreach ( (array) $banned_names as $banned_domain ) {

			if ( $banned_domain == '' )

				continue;

			if (

				strstr( $email_domain, $banned_domain ) ||

				(

					strstr( $banned_domain, '/' ) &&

					preg_match( $banned_domain, $email_domain )

				)

			)

			return true;

		}

	}

	return false;

}



/**

 * Processes new user registrations.

 *

 * Checks the data provided by the user during signup. Verifies

 * the validity and uniqueness of user names and user email addresses,

 * and checks email addresses against admin-provided domain

 * whitelists and blacklists.

 *

 * The hook 'wpmu_validate_user_signup' provides an easy way

 * to modify the signup process. The value $result, which is passed

 * to the hook, contains both the user-provided info and the error

 * messages created by the function. 'wpmu_validate_user_signup' allows

 * you to process the data in any way you'd like, and unset the

 * relevant errors if necessary.

 *

 * @since MU

 * @uses is_email_address_unsafe()

 * @uses username_exists()

 * @uses email_exists()

 *

 * @param string $user_name The login name provided by the user.

 * @param string $user_email The email provided by the user.

 * @return array Contains username, email, and error messages.

 */

function wpmu_validate_user_signup($user_name, $user_email) {

	global $wpdb;



	$errors = new WP_Error();



	$orig_username = $user_name;

	$user_name = preg_replace( '/\s+/', '', sanitize_user( $user_name, true ) );

	$maybe = array();

	preg_match( '/[a-z0-9]+/', $user_name, $maybe );



	if ( $user_name != $orig_username || $user_name != $maybe[0] ) {

		$errors->add( 'user_name', __( 'Only lowercase letters (a-z) and numbers are allowed.' ) );

		$user_name = $orig_username;

	}



	$user_email = sanitize_email( $user_email );



	if ( empty( $user_name ) )

	   	$errors->add('user_name', __('Please enter a username'));



	$illegal_names = get_site_option( 'illegal_names' );

	if ( is_array( $illegal_names ) == false ) {

		$illegal_names = array(  'www', 'web', 'root', 'admin', 'main', 'invite', 'administrator' );

		add_site_option( 'illegal_names', $illegal_names );

	}

	if ( in_array( $user_name, $illegal_names ) == true )

		$errors->add('user_name',  __('That username is not allowed'));



	if ( is_email_address_unsafe( $user_email ) )

		$errors->add('user_email',  __('You cannot use that email address to signup. We are having problems with them blocking some of our email. Please use another email provider.'));



	if ( strlen( $user_name ) < 4 )

		$errors->add('user_name',  __('Username must be at least 4 characters'));



	if ( strpos( ' ' . $user_name, '_' ) != false )

		$errors->add( 'user_name', __( 'Sorry, usernames may not contain the character &#8220;_&#8221;!' ) );



	// all numeric?

	$match = array();

	preg_match( '/[0-9]*/', $user_name, $match );

	if ( $match[0] == $user_name )

		$errors->add('user_name', __('Sorry, usernames must have letters too!'));



	if ( !is_email( $user_email ) )

		$errors->add('user_email', __('Please enter a correct email address'));



	$limited_email_domains = get_site_option( 'limited_email_domains' );

	if ( is_array( $limited_email_domains ) && empty( $limited_email_domains ) == false ) {

		$emaildomain = substr( $user_email, 1 + strpos( $user_email, '@' ) );

		if ( in_array( $emaildomain, $limited_email_domains ) == false )

			$errors->add('user_email', __('Sorry, that email address is not allowed!'));

	}



	// Check if the username has been used already.

	if ( username_exists($user_name) )

		$errors->add('user_name', __('Sorry, that username already exists!'));



	// Check if the email address has been used already.

	if ( email_exists($user_email) )

		$errors->add('user_email', __('Sorry, that email address is already used!'));



	// Has someone already signed up for this username?

	$signup = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->signups WHERE user_login = %s", $user_name) );

	if ( $signup != null ) {

		$registered_at =  mysql2date('U', $signup->registered);

		$now = current_time( 'timestamp', true );

		$diff = $now - $registered_at;

		// If registered more than two days ago, cancel registration and let this signup go through.

		if ( $diff > 172800 )

			$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->signups WHERE user_login = %s", $user_name) );

		else

			$errors->add('user_name', __('That username is currently reserved but may be available in a couple of days.'));



		if ( $signup->active == 0 && $signup->user_email == $user_email )

			$errors->add('user_email_used', __('username and email used'));

	}



	$signup = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->signups WHERE user_email = %s", $user_email) );

	if ( $signup != null ) {

		$diff = current_time( 'timestamp', true ) - mysql2date('U', $signup->registered);

		// If registered more than two days ago, cancel registration and let this signup go through.

		if ( $diff > 172800 )

			$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->signups WHERE user_email = %s", $user_email) );

		else

			$errors->add('user_email', __('That email address has already been used. Please check your inbox for an activation email. It will become available in a couple of days if you do nothing.'));

	}



	$result = array('user_name' => $user_name, 'orig_username' => $orig_username, 'user_email' => $user_email, 'errors' => $errors);



	return apply_filters('wpmu_validate_user_signup', $result);

}



/**

 * Processes new site registrations.

 *

 * Checks the data provided by the user during blog signup. Verifies

 * the validity and uniqueness of blog paths and domains.

 *

 * This function prevents the current user from registering a new site

 * with a blogname equivalent to another user's login name. Passing the

 * $user parameter to the function, where $user is the other user, is

 * effectively an override of this limitation.

 *

 * Filter 'wpmu_validate_blog_signup' if you want to modify

 * the way that WordPress validates new site signups.

 *

 * @since MU

 * @uses domain_exists()

 * @uses username_exists()

 *

 * @param string $blogname The blog name provided by the user. Must be unique.

 * @param string $blog_title The blog title provided by the user.

 * @return array Contains the new site data and error messages.

 */

function wpmu_validate_blog_signup($blogname, $blog_title, $user = '') {

	global $wpdb, $domain, $base, $current_site;



	$blog_title = strip_tags( $blog_title );

	$blog_title = substr( $blog_title, 0, 50 );



	$errors = new WP_Error();

	$illegal_names = get_site_option( 'illegal_names' );

	if ( $illegal_names == false ) {

		$illegal_names = array( 'www', 'web', 'root', 'admin', 'main', 'invite', 'administrator' );

		add_site_option( 'illegal_names', $illegal_names );

	}



	// On sub dir installs, Some names are so illegal, only a filter can spring them from jail

	if (! is_subdomain_install() )

		$illegal_names = array_merge($illegal_names, apply_filters( 'subdirectory_reserved_names', array( 'page', 'comments', 'blog', 'files', 'feed' ) ) );





	if ( empty( $blogname ) )

		$errors->add('blogname', __('Please enter a site name'));



	$maybe = array();

	preg_match( '/[a-z0-9]+/', $blogname, $maybe );

	if ( $blogname != $maybe[0] )

		$errors->add('blogname', __('Only lowercase letters and numbers allowed'));



	if ( in_array( $blogname, $illegal_names ) == true )

		$errors->add('blogname',  __('That name is not allowed'));



	if ( strlen( $blogname ) < 4 && !is_super_admin() )

		$errors->add('blogname',  __('Site name must be at least 4 characters'));



	if ( strpos( ' ' . $blogname, '_' ) != false )

		$errors->add( 'blogname', __( 'Sorry, site names may not contain the character &#8220;_&#8221;!' ) );



	// do not allow users to create a blog that conflicts with a page on the main blog.

	if ( !is_subdomain_install() && $wpdb->get_var( $wpdb->prepare( "SELECT post_name FROM " . $wpdb->get_blog_prefix( $current_site->blog_id ) . "posts WHERE post_type = 'page' AND post_name = %s", $blogname ) ) )

		$errors->add( 'blogname', __( 'Sorry, you may not use that site name.' ) );



	// all numeric?

	$match = array();

	preg_match( '/[0-9]*/', $blogname, $match );

	if ( $match[0] == $blogname )

		$errors->add('blogname', __('Sorry, site names must have letters too!'));



	$blogname = apply_filters( 'newblogname', $blogname );



	$blog_title = stripslashes(  $blog_title );



	if ( empty( $blog_title ) )

		$errors->add('blog_title', __('Please enter a site title'));



	// Check if the domain/path has been used already.

	if ( is_subdomain_install() ) {

		$mydomain = $blogname . '.' . preg_replace( '|^www\.|', '', $domain );

		$path = $base;

	} else {

		$mydomain = "$domain";

		$path = $base.$blogname.'/';

	}

	if ( domain_exists($mydomain, $path) )

		$errors->add('blogname', __('Sorry, that site already exists!'));



	if ( username_exists( $blogname ) ) {

		if ( is_object( $user ) == false || ( is_object($user) && ( $user->user_login != $blogname ) ) )

			$errors->add( 'blogname', __( 'Sorry, that site is reserved!' ) );

	}



	// Has someone already signed up for this domain?

	$signup = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->signups WHERE domain = %s AND path = %s", $mydomain, $path) ); // TODO: Check email too?

	if ( ! empty($signup) ) {

		$diff = current_time( 'timestamp', true ) - mysql2date('U', $signup->registered);

		// If registered more than two days ago, cancel registration and let this signup go through.

		if ( $diff > 172800 )

			$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->signups WHERE domain = %s AND path = %s", $mydomain, $path) );

		else

			$errors->add('blogname', __('That site is currently reserved but may be available in a couple days.'));

	}



	$result = array('domain' => $mydomain, 'path' => $path, 'blogname' => $blogname, 'blog_title' => $blog_title, 'errors' => $errors);

	return apply_filters('wpmu_validate_blog_signup', $result);

}



/**

 * Record site signup information for future activation.

 *

 * @since MU

 * @uses wpmu_signup_blog_notification()

 *

 * @param string $domain The requested domain.

 * @param string $path The requested path.

 * @param string $title The requested site title.

 * @param string $user The user's requested login name.

 * @param string $user_email The user's email address.

 * @param array $meta By default, contains the requested privacy setting and lang_id.

 */

function wpmu_signup_blog($domain, $path, $title, $user, $user_email, $meta = '') {

	global $wpdb;



	$key = substr( md5( time() . rand() . $domain ), 0, 16 );

	$meta = serialize($meta);

	$domain = $wpdb->escape($domain);

	$path = $wpdb->escape($path);

	$title = $wpdb->escape($title);



	$wpdb->insert( $wpdb->signups, array(

		'domain' => $domain,

		'path' => $path,

		'title' => $title,

		'user_login' => $user,

		'user_email' => $user_email,

		'registered' => current_time('mysql', true),

		'activation_key' => $key,

		'meta' => $meta

	) );



	wpmu_signup_blog_notification($domain, $path, $title, $user, $user_email, $key, $meta);

}



/**

 * Record user signup information for future activation.

 *

 * This function is used when user registration is open but

 * new site registration is not.

 *

 * @since MU

 * @uses wpmu_signup_user_notification()

 *

 * @param string $user The user's requested login name.

 * @param string $user_email The user's email address.

 * @param array $meta By default, this is an empty array.

 */

function wpmu_signup_user($user, $user_email, $meta = '') {

	global $wpdb;



	// Format data

	$user = preg_replace( '/\s+/', '', sanitize_user( $user, true ) );

	$user_email = sanitize_email( $user_email );

	$key = substr( md5( time() . rand() . $user_email ), 0, 16 );

	$meta = serialize($meta);



	$wpdb->insert( $wpdb->signups, array(

		'domain' => '',

		'path' => '',

		'title' => '',

		'user_login' => $user,

		'user_email' => $user_email,

		'registered' => current_time('mysql', true),

		'activation_key' => $key,

		'meta' => $meta

	) );



	wpmu_signup_user_notification($user, $user_email, $key, $meta);

}



/**

 * Notify user of signup success.

 *

 * This is the notification function used when site registration

 * is enabled.

 *

 * Filter 'wpmu_signup_blog_notification' to bypass this function or

 * replace it with your own notification behavior.

 *

 * Filter 'wpmu_signup_blog_notification_email' and

 * 'wpmu_signup_blog_notification_email' to change the content

 * and subject line of the email sent to newly registered users.

 *

 * @since MU

 *

 * @param string $domain The new blog domain.

 * @param string $path The new blog path.

 * @param string $title The site title.

 * @param string $user The user's login name.

 * @param string $user_email The user's email address.

 * @param array $meta By default, contains the requested privacy setting and lang_id.

 * @param string $key The activation key created in wpmu_signup_blog()

 * @return bool

 */

function wpmu_signup_blog_notification($domain, $path, $title, $user, $user_email, $key, $meta = '') {

	global $current_site;



	if ( !apply_filters('wpmu_signup_blog_notification', $domain, $path, $title, $user, $user_email, $key, $meta) )

		return false;



	// Send email with activation link.

	if ( !is_subdomain_install() || $current_site->id != 1 )

		$activate_url = network_site_url("wp-activate.php?key=$key");

	else

		$activate_url = "http://{$domain}{$path}wp-activate.php?key=$key"; // @todo use *_url() API



	$activate_url = esc_url($activate_url);

	$admin_email = get_site_option( 'admin_email' );

	if ( $admin_email == '' )

		$admin_email = 'support@' . $_SERVER['SERVER_NAME'];

	$from_name = get_site_option( 'site_name' ) == '' ? 'WordPress' : esc_html( get_site_option( 'site_name' ) );

	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";

	$message = sprintf(

		apply_filters( 'wpmu_signup_blog_notification_email',

			__( "To activate your blog, please click the following link:\n\n%s\n\nAfter you activate, you will receive *another email* with your login.\n\nAfter you activate, you can visit your site here:\n\n%s" ),

			$domain, $path, $title, $user, $user_email, $key, $meta

		),

		$activate_url,

		esc_url( "http://{$domain}{$path}" ),

		$key

	);

	// TODO: Don't hard code activation link.

	$subject = sprintf(

		apply_filters( 'wpmu_signup_blog_notification_subject',

			__( '[%1$s] Activate %2$s' ),

			$domain, $path, $title, $user, $user_email, $key, $meta

		),

		$from_name,

		esc_url( 'http://' . $domain . $path )

	);

	wp_mail($user_email, $subject, $message, $message_headers);

	return true;

}



/**

 * Notify user of signup success.

 *

 * This is the notification function used when no new site has

 * been requested.

 *

 * Filter 'wpmu_signup_user_notification' to bypass this function or

 * replace it with your own notification behavior.

 *

 * Filter 'wpmu_signup_user_notification_email' and

 * 'wpmu_signup_user_notification_subject' to change the content

 * and subject line of the email sent to newly registered users.

 *

 * @since MU

 *

 * @param string $user The user's login name.

 * @param string $user_email The user's email address.

 * @param array $meta By default, an empty array.

 * @param string $key The activation key created in wpmu_signup_user()

 * @return bool

 */

function wpmu_signup_user_notification($user, $user_email, $key, $meta = '') {

	if ( !apply_filters('wpmu_signup_user_notification', $user, $user_email, $key, $meta) )

		return false;



	// Send email with activation link.

	$admin_email = get_site_option( 'admin_email' );

	if ( $admin_email == '' )

		$admin_email = 'support@' . $_SERVER['SERVER_NAME'];

	$from_name = get_site_option( 'site_name' ) == '' ? 'WordPress' : esc_html( get_site_option( 'site_name' ) );

	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";

	$message = sprintf(

		apply_filters( 'wpmu_signup_user_notification_email',

			__( "To activate your user, please click the following link:\n\n%s\n\nAfter you activate, you will receive *another email* with your login.\n\n" ),

			$user, $user_email, $key, $meta

		),

		site_url( "wp-activate.php?key=$key" )

	);

	// TODO: Don't hard code activation link.

	$subject = sprintf(

		apply_filters( 'wpmu_signup_user_notification_subject',

			__( '[%1$s] Activate %2$s' ),

			$user, $user_email, $key, $meta

		),

		$from_name,

		$user

	);

	wp_mail($user_email, $subject, $message, $message_headers);

	return true;

}



/**

 * Activate a signup.

 *

 * Hook to 'wpmu_activate_user' or 'wpmu_activate_blog' for events

 * that should happen only when users or sites are self-created (since

 * those actions are not called when users and sites are created

 * by a Super Admin).

 *

 * @since MU

 * @uses wp_generate_password()

 * @uses wpmu_welcome_user_notification()

 * @uses add_user_to_blog()

 * @uses add_new_user_to_blog()

 * @uses wpmu_create_user()

 * @uses wpmu_create_blog()

 * @uses wpmu_welcome_notification()

 *

 * @param string $key The activation key provided to the user.

 * @return array An array containing information about the activated user and/or blog

 */

function wpmu_activate_signup($key) {

	global $wpdb, $current_site;



	$signup = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->signups WHERE activation_key = %s", $key) );



	if ( empty( $signup ) )

		return new WP_Error( 'invalid_key', __( 'Invalid activation key.' ) );



	if ( $signup->active ) {

		if ( empty( $signup->domain ) )

			return new WP_Error( 'already_active', __( 'The user is already active.' ), $signup );

		else

			return new WP_Error( 'already_active', __( 'The site is already active.' ), $signup );

	}



	$meta = unserialize($signup->meta);

	$user_login = $wpdb->escape($signup->user_login);

	$user_email = $wpdb->escape($signup->user_email);

	$password = wp_generate_password( 12, false );



	$user_id = username_exists($user_login);



	if ( ! $user_id )

		$user_id = wpmu_create_user($user_login, $password, $user_email);

	else

		$user_already_exists = true;



	if ( ! $user_id )

		return new WP_Error('create_user', __('Could not create user'), $signup);



	$now = current_time('mysql', true);



	if ( empty($signup->domain) ) {

		$wpdb->update( $wpdb->signups, array('active' => 1, 'activated' => $now), array('activation_key' => $key) );



		if ( isset( $user_already_exists ) )

			return new WP_Error( 'user_already_exists', __( 'That username is already activated.' ), $signup);



		wpmu_welcome_user_notification($user_id, $password, $meta);



		add_new_user_to_blog( $user_id, $user_email, $meta );

		do_action('wpmu_activate_user', $user_id, $password, $meta);

		return array('user_id' => $user_id, 'password' => $password, 'meta' => $meta);

	}



	$blog_id = wpmu_create_blog( $signup->domain, $signup->path, $signup->title, $user_id, $meta, $wpdb->siteid );



	// TODO: What to do if we create a user but cannot create a blog?

	if ( is_wp_error($blog_id) ) {

		// If blog is taken, that means a previous attempt to activate this blog failed in between creating the blog and

		// setting the activation flag.  Let's just set the active flag and instruct the user to reset their password.

		if ( 'blog_taken' == $blog_id->get_error_code() ) {

			$blog_id->add_data( $signup );

			$wpdb->update( $wpdb->signups, array( 'active' => 1, 'activated' => $now ), array( 'activation_key' => $key ) );

		}

		return $blog_id;

	}



	$wpdb->update( $wpdb->signups, array('active' => 1, 'activated' => $now), array('activation_key' => $key) );

	wpmu_welcome_notification($blog_id, $user_id, $password, $signup->title, $meta);

	do_action('wpmu_activate_blog', $blog_id, $user_id, $password, $signup->title, $meta);



	return array('blog_id' => $blog_id, 'user_id' => $user_id, 'password' => $password, 'title' => $signup->title, 'meta' => $meta);

}



/**

 * Create a user.

 *

 * This function runs when a user self-registers as well as when

 * a Super Admin creates a new user. Hook to 'wpmu_new_user' for events

 * that should affect all new users, but only on Multisite (otherwise

 * use 'user_register').

 *

 * @since MU

 * @uses wp_create_user()

 *

 * @param string $user_name The new user's login name.

 * @param string $password The new user's password.

 * @param string $email The new user's email address.

 * @return mixed Returns false on failure, or int $user_id on success

 */

function wpmu_create_user( $user_name, $password, $email) {

	$user_name = preg_replace( '/\s+/', '', sanitize_user( $user_name, true ) );



	$user_id = wp_create_user( $user_name, $password, $email );

	if ( is_wp_error($user_id) )

		return false;



	// Newly created users have no roles or caps until they are added to a blog.

	delete_user_option( $user_id, 'capabilities' );

	delete_user_option( $user_id, 'user_level' );



	do_action( 'wpmu_new_user', $user_id );



	return $user_id;

}



/**

 * Create a site.

 *

 * This function runs when a user self-registers a new site as well

 * as when a Super Admin creates a new site. Hook to 'wpmu_new_blog'

 * for events that should affect all new sites.

 *

 * On subdirectory installs, $domain is the same as the main site's

 * domain, and the path is the subdirectory name (eg 'example.com'

 * and '/blog1/'). On subdomain installs, $domain is the new subdomain +

 * root domain (eg 'blog1.example.com'), and $path is '/'.

 *

 * @since MU

 * @uses domain_exists()

 * @uses insert_blog()

 * @uses wp_install_defaults()

 * @uses add_user_to_blog()

 *

 * @param string $domain The new site's domain.

 * @param string $path The new site's path.

 * @param string $title The new site's title.

 * @param int $user_id The user ID of the new site's admin.

 * @param array $meta Optional. Used to set initial site options.

 * @param int $site_id Optional. Only relevant on multi-network installs.

 * @return mixed Returns WP_Error object on failure, int $blog_id on success

 */

function wpmu_create_blog($domain, $path, $title, $user_id, $meta = '', $site_id = 1) {

	$domain = preg_replace( '/\s+/', '', sanitize_user( $domain, true ) );



	if ( is_subdomain_install() )

		$domain = str_replace( '@', '', $domain );



	$title = strip_tags( $title );

	$user_id = (int) $user_id;



	if ( empty($path) )

		$path = '/';



	// Check if the domain has been used already. We should return an error message.

	if ( domain_exists($domain, $path, $site_id) )

		return new WP_Error('blog_taken', __('Site already exists.'));



	if ( !defined('WP_INSTALLING') )

		define( 'WP_INSTALLING', true );



	if ( ! $blog_id = insert_blog($domain, $path, $site_id) )

		return new WP_Error('insert_blog', __('Could not create site.'));



	switch_to_blog($blog_id);

	install_blog($blog_id, $title);

	wp_install_defaults($user_id);



	add_user_to_blog($blog_id, $user_id, 'administrator');



	if ( is_array($meta) ) foreach ($meta as $key => $value) {

		if ( $key == 'public' || $key == 'archived' || $key == 'mature' || $key == 'spam' || $key == 'deleted' || $key == 'lang_id' )

			update_blog_status( $blog_id, $key, $value );

		else

			update_option( $key, $value );

	}



	add_option( 'WPLANG', get_site_option( 'WPLANG' ) );

	update_option( 'blog_public', (int)$meta['public'] );



	if ( !is_super_admin() && ! get_user_meta( $user_id, 'primary_blog', true ) )

		update_user_meta( $user_id, 'primary_blog', $blog_id );



	restore_current_blog();

	do_action( 'wpmu_new_blog', $blog_id, $user_id, $domain, $path, $site_id, $meta );



	return $blog_id;

}



/**

 * Notifies the network admin that a new site has been activated.

 *

 * Filter 'newblog_notify_siteadmin' to change the content of

 * the notification email.

 *

 * @since MU

 *

 * @param int $blog_id The new site's ID.

 * @return bool

 */

function newblog_notify_siteadmin( $blog_id, $deprecated = '' ) {

	if ( get_site_option( 'registrationnotification' ) != 'yes' )

		return false;



	$email = get_site_option( 'admin_email' );

	if ( is_email($email) == false )

		return false;



	$options_site_url = esc_url(network_admin_url('settings.php'));



	switch_to_blog( $blog_id );

	$blogname = get_option( 'blogname' );

	$siteurl = site_url();

	restore_current_blog();



	$msg = sprintf( __( 'New Site: %1s

URL: %2s

Remote IP: %3s



Disable these notifications: %4s' ), $blogname, $siteurl, $_SERVER['REMOTE_ADDR'], $options_site_url);

	$msg = apply_filters( 'newblog_notify_siteadmin', $msg );



	wp_mail( $email, sprintf( __( 'New Site Registration: %s' ), $siteurl ), $msg );

	return true;

}



/**

 * Notifies the network admin that a new user has been activated.

 *

 * Filter 'newuser_notify_siteadmin' to change the content of

 * the notification email.

 *

 * @since MU

 *

 * @param int $user_id The new user's ID.

 * @return bool

 */

function newuser_notify_siteadmin( $user_id ) {

	if ( get_site_option( 'registrationnotification' ) != 'yes' )

		return false;



	$email = get_site_option( 'admin_email' );



	if ( is_email($email) == false )

		return false;



	$user = new WP_User($user_id);



	$options_site_url = esc_url(network_admin_url('settings.php'));

	$msg = sprintf(__('New User: %1s

Remote IP: %2s



Disable these notifications: %3s'), $user->user_login, $_SERVER['REMOTE_ADDR'], $options_site_url);



	$msg = apply_filters( 'newuser_notify_siteadmin', $msg );

	wp_mail( $email, sprintf(__('New User Registration: %s'), $user->user_login), $msg );

	return true;

}



/**

 * Check whether a blogname is already taken.

 *

 * Used during the new site registration process to ensure

 * that each blogname is unique.

 *

 * @since MU

 *

 * @param string $domain The domain to be checked.

 * @param string $path The path to be checked.

 * @param int $site_id Optional. Relevant only on multi-network installs.

 * @return int

 */

function domain_exists($domain, $path, $site_id = 1) {

	global $wpdb;

	return $wpdb->get_var( $wpdb->prepare("SELECT blog_id FROM $wpdb->blogs WHERE domain = %s AND path = %s AND site_id = %d", $domain, $path, $site_id) );

}



/**

 * Store basic site info in the blogs table.

 *

 * This function creates a row in the wp_blogs table and returns

 * the new blog's ID. It is the first step in creating a new blog.

 *

 * @since MU

 *

 * @param string $domain The domain of the new site.

 * @param string $path The path of the new site.

 * @param int $site_id Unless you're running a multi-network install, be sure to set this value to 1.

 * @return int The ID of the new row

 */

function insert_blog($domain, $path, $site_id) {

	global $wpdb;



	$path = trailingslashit($path);

	$site_id = (int) $site_id;



	$result = $wpdb->insert( $wpdb->blogs, array('site_id' => $site_id, 'domain' => $domain, 'path' => $path, 'registered' => current_time('mysql')) );

	if ( ! $result )

		return false;



	refresh_blog_details($wpdb->insert_id);

	return $wpdb->insert_id;

}



/**

 * Install an empty blog.

 *

 * Creates the new blog tables and options. If calling this function

 * directly, be sure to use switch_to_blog() first, so that $wpdb

 * points to the new blog.

 *

 * @since MU

 * @uses make_db_current_silent()

 * @uses populate_roles()

 *

 * @param int $blog_id The value returned by insert_blog().

 * @param string $blog_title The title of the new site.

 */

function install_blog($blog_id, $blog_title = '') {

	global $wpdb, $table_prefix, $wp_roles;

	$wpdb->suppress_errors();



	// Cast for security

	$blog_id = (int) $blog_id;



	require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );



	if ( $wpdb->get_results("SELECT ID FROM $wpdb->posts") )

		die(__('<h1>Already Installed</h1><p>You appear to have already installed WordPress. To reinstall please clear your old database tables first.</p>') . '</body></html>');



	$wpdb->suppress_errors(false);



	$url = get_blogaddress_by_id($blog_id);



	// Set everything up

	make_db_current_silent();

	populate_options();

	populate_roles();

	$wp_roles->_init();



	// fix url.

	update_option('siteurl', $url);

	update_option('home', $url);

	update_option('fileupload_url', $url . "files" );

	update_option('upload_path', UPLOADBLOGSDIR . "/$blog_id/files");

	update_option('blogname', stripslashes( $blog_title ) );

	update_option('admin_email', '');

	$wpdb->update( $wpdb->options, array('option_value' => ''), array('option_name' => 'admin_email') );



	// remove all perms

	$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->usermeta WHERE meta_key = %s", $table_prefix.'user_level') );

	$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->usermeta WHERE meta_key = %s", $table_prefix.'capabilities') );



	$wpdb->suppress_errors( false );

}



/**

 * Set blog defaults.

 *

 * This function creates a row in the wp_blogs table.

 *

 * @since MU

 * @deprecated MU

 * @deprecated Use wp_install_defaults()

 * @uses wp_install_defaults()

 *

 * @param int $blog_id Ignored in this function.

 * @param int $user_id

 */

function install_blog_defaults($blog_id, $user_id) {

	global $wpdb;



	require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );



	$wpdb->suppress_errors();



	wp_install_defaults($user_id);



	$wpdb->suppress_errors( false );

}



/**

 * Notify a user that her blog activation has been successful.

 *

 * Filter 'wpmu_welcome_notification' to disable or bypass.

 *

 * Filter 'update_welcome_email' and 'update_welcome_subject' to

 * modify the content and subject line of the notification email.

 *

 * @since MU

 *

 * @param int $blog_id

 * @param int $user_id

 * @param string $password

 * @param string $title The new blog's title

 * @param array $meta Optional. Not used in the default function, but is passed along to hooks for customization.

 * @return bool

 */

function wpmu_welcome_notification($blog_id, $user_id, $password, $title, $meta = '') {

	global $current_site;



	if ( !apply_filters('wpmu_welcome_notification', $blog_id, $user_id, $password, $title, $meta) )

		return false;



	$welcome_email = stripslashes( get_site_option( 'welcome_email' ) );

	if ( $welcome_email == false )

		$welcome_email = stripslashes( __( 'Dear User,



Your new SITE_NAME site has been successfully set up at:

BLOG_URL



You can log in to the administrator account with the following information:

Username: USERNAME

Password: PASSWORD

Log in here: BLOG_URLwp-login.php



We hope you enjoy your new site. Thanks!



--The Team @ SITE_NAME' ) );



	$url = get_blogaddress_by_id($blog_id);

	$user = new WP_User($user_id);



	$welcome_email = str_replace( 'SITE_NAME', $current_site->site_name, $welcome_email );

	$welcome_email = str_replace( 'BLOG_TITLE', $title, $welcome_email );

	$welcome_email = str_replace( 'BLOG_URL', $url, $welcome_email );

	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );

	$welcome_email = str_replace( 'PASSWORD', $password, $welcome_email );



	$welcome_email = apply_filters( 'update_welcome_email', $welcome_email, $blog_id, $user_id, $password, $title, $meta);

	$admin_email = get_site_option( 'admin_email' );



	if ( $admin_email == '' )

		$admin_email = 'support@' . $_SERVER['SERVER_NAME'];



	$from_name = get_site_option( 'site_name' ) == '' ? 'WordPress' : esc_html( get_site_option( 'site_name' ) );

	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";

	$message = $welcome_email;



	if ( empty( $current_site->site_name ) )

		$current_site->site_name = 'WordPress';



	$subject = apply_filters( 'update_welcome_subject', sprintf(__('New %1$s Site: %2$s'), $current_site->site_name, stripslashes( $title ) ) );

	wp_mail($user->user_email, $subject, $message, $message_headers);

	return true;

}



/**

 * Notify a user that her account activation has been successful.

 *

 * Filter 'wpmu_welcome_user_notification' to disable or bypass.

 *

 * Filter 'update_welcome_user_email' and 'update_welcome_user_subject' to

 * modify the content and subject line of the notification email.

 *

 * @since MU

 *

 * @param int $user_id

 * @param string $password

 * @param array $meta Optional. Not used in the default function, but is passed along to hooks for customization.

 * @return bool

 */

function wpmu_welcome_user_notification($user_id, $password, $meta = '') {

	global $current_site;



	if ( !apply_filters('wpmu_welcome_user_notification', $user_id, $password, $meta) )

		return false;



	$welcome_email = get_site_option( 'welcome_user_email' );



	$user = new WP_User($user_id);



	$welcome_email = apply_filters( 'update_welcome_user_email', $welcome_email, $user_id, $password, $meta);

	$welcome_email = str_replace( 'SITE_NAME', $current_site->site_name, $welcome_email );

	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );

	$welcome_email = str_replace( 'PASSWORD', $password, $welcome_email );

	$welcome_email = str_replace( 'LOGINLINK', wp_login_url(), $welcome_email );



	$admin_email = get_site_option( 'admin_email' );



	if ( $admin_email == '' )

		$admin_email = 'support@' . $_SERVER['SERVER_NAME'];



	$from_name = get_site_option( 'site_name' ) == '' ? 'WordPress' : esc_html( get_site_option( 'site_name' ) );

	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";

	$message = $welcome_email;



	if ( empty( $current_site->site_name ) )

		$current_site->site_name = 'WordPress';



	$subject = apply_filters( 'update_welcome_user_subject', sprintf(__('New %1$s User: %2$s'), $current_site->site_name, $user->user_login) );

	wp_mail($user->user_email, $subject, $message, $message_headers);

	return true;

}



/**

 * Get the current site info.

 *

 * Returns an object containing the ID, domain, path, and site_name

 * of the site being viewed.

 *

 * @since MU

 *

 * @return object

 */

function get_current_site() {

	global $current_site;

	return $current_site;

}



/**

 * Get a numeric user ID from either an email address or a login.

 *

 * @since MU

 * @uses is_email()

 *

 * @param string $string

 * @return int

 */

function get_user_id_from_string( $string ) {

	$user_id = 0;

	if ( is_email( $string ) ) {

		$user = get_user_by('email', $string);

		if ( $user )

			$user_id = $user->ID;

	} elseif ( is_numeric( $string ) ) {

		$user_id = $string;

	} else {

		$user = get_user_by('login', $string);

		if ( $user )

			$user_id = $user->ID;

	}



	return $user_id;

}



/**

 * Get a user's most recent post.

 *

 * Walks through each of a user's blogs to find the post with

 * the most recent post_date_gmt.

 *

 * @since MU

 * @uses get_blogs_of_user()

 *

 * @param int $user_id

 * @return array Contains the blog_id, post_id, post_date_gmt, and post_gmt_ts

 */

function get_most_recent_post_of_user( $user_id ) {

	global $wpdb;



	$user_blogs = get_blogs_of_user( (int) $user_id );

	$most_recent_post = array();



	// Walk through each blog and get the most recent post

	// published by $user_id

	foreach ( (array) $user_blogs as $blog ) {

		$recent_post = $wpdb->get_row( $wpdb->prepare("SELECT ID, post_date_gmt FROM {$wpdb->base_prefix}{$blog->userblog_id}_posts WHERE post_author = %d AND post_type = 'post' AND post_status = 'publish' ORDER BY post_date_gmt DESC LIMIT 1", $user_id ), ARRAY_A);



		// Make sure we found a post

		if ( isset($recent_post['ID']) ) {

			$post_gmt_ts = strtotime($recent_post['post_date_gmt']);



			// If this is the first post checked or if this post is

			// newer than the current recent post, make it the new

			// most recent post.

			if ( !isset($most_recent_post['post_gmt_ts']) || ( $post_gmt_ts > $most_recent_post['post_gmt_ts'] ) ) {

				$most_recent_post = array(

					'blog_id'		=> $blog->userblog_id,

					'post_id'		=> $recent_post['ID'],

					'post_date_gmt'	=> $recent_post['post_date_gmt'],

					'post_gmt_ts'	=> $post_gmt_ts

				);

			}

		}

	}



	return $most_recent_post;

}



// Misc functions



/**

 * Get the size of a directory.

 *

 * A helper function that is used primarily to check whether

 * a blog has exceeded its allowed upload space.

 *

 * @since MU

 * @uses recurse_dirsize()

 *

 * @param string $directory

 * @return int

 */

function get_dirsize( $directory ) {

	$dirsize = get_transient( 'dirsize_cache' );

	if ( is_array( $dirsize ) && isset( $dirsize[ $directory ][ 'size' ] ) )

		return $dirsize[ $directory ][ 'size' ];



	if ( false == is_array( $dirsize ) )

		$dirsize = array();



	$dirsize[ $directory ][ 'size' ] = recurse_dirsize( $directory );



	set_transient( 'dirsize_cache', $dirsize, 3600 );

	return $dirsize[ $directory ][ 'size' ];

}



/**

 * Get the size of a directory recursively.

 *

 * Used by get_dirsize() to get a directory's size when it contains

 * other directories.

 *

 * @since MU

 *

 * @param string $directory

 * @return int

 */

function recurse_dirsize( $directory ) {

	$size = 0;



	if ( substr( $directory, -1 ) == '/' )

		$directory = substr($directory,0,-1);



	if ( !file_exists($directory) || !is_dir( $directory ) || !is_readable( $directory ) )

		return false;



	if ($handle = opendir($directory)) {

		while(($file = readdir($handle)) !== false) {

			$path = $directory.'/'.$file;

			if ($file != '.' && $file != '..') {

				if (is_file($path)) {

					$size += filesize($path);

				} elseif (is_dir($path)) {

					$handlesize = recurse_dirsize($path);

					if ($handlesize > 0)

						$size += $handlesize;

				}

			}

		}

		closedir($handle);

	}

	return $size;

}



/**

 * Check whether a blog has used its allotted upload space.

 *

 * Used by get_dirsize() to get a directory's size when it contains

 * other directories.

 *

 * @since MU

 * @uses get_dirsize()

 *

 * @param bool $echo Optional. If $echo is set and the quota is exceeded, a warning message is echoed. Default is true.

 * @return int

 */

function upload_is_user_over_quota( $echo = true ) {

	if ( get_site_option( 'upload_space_check_disabled' ) )

		return false;



	$spaceAllowed = get_space_allowed();

	if ( empty( $spaceAllowed ) || !is_numeric( $spaceAllowed ) )

		$spaceAllowed = 10;	// Default space allowed is 10 MB



	$dirName = BLOGUPLOADDIR;

	$size = get_dirsize($dirName) / 1024 / 1024;



	if ( ($spaceAllowed-$size) < 0 ) {

		if ( $echo )

			_e( 'Sorry, you have used your space allocation. Please delete some files to upload more files.' ); // No space left

		return true;

	} else {

		return false;

	}

}



/**

 * Check an array of MIME types against a whitelist.

 *

 * WordPress ships with a set of allowed upload filetypes,

 * which is defined in wp-includes/functions.php in

 * get_allowed_mime_types(). This function is used to filter

 * that list against the filetype whitelist provided by Multisite

 * Super Admins at wp-admin/network/settings.php.

 *

 * @since MU

 *

 * @param array $mimes

 * @return array

 */

function check_upload_mimes( $mimes ) {

	$site_exts = explode( ' ', get_site_option( 'upload_filetypes' ) );

	foreach ( $site_exts as $ext ) {

		foreach ( $mimes as $ext_pattern => $mime ) {

			if ( $ext != '' && strpos( $ext_pattern, $ext ) !== false )

				$site_mimes[$ext_pattern] = $mime;

		}

	}

	return $site_mimes;

}



/**

 * Update a blog's post count.

 *

 * WordPress MS stores a blog's post count as an option so as

 * to avoid extraneous COUNTs when a blog's details are fetched

 * with get_blog_details(). This function is called when posts

 * are published to make sure the count stays current.

 *

 * @since MU

 */

function update_posts_count( $deprecated = '' ) {

	global $wpdb;

	update_option( 'post_count', (int) $wpdb->get_var( "SELECT COUNT(ID) FROM {$wpdb->posts} WHERE post_status = 'publish' and post_type = 'post'" ) );

}



/**

 * Logs user registrations.

 *

 * @since MU

 *

 * @param int $blog_id

 * @param int $user_id

 */

function wpmu_log_new_registrations( $blog_id, $user_id ) {

	global $wpdb;

	$user = new WP_User( (int) $user_id );

	$wpdb->insert( $wpdb->registration_log, array('email' => $user->user_email, 'IP' => preg_replace( '/[^0-9., ]/', '',$_SERVER['REMOTE_ADDR'] ), 'blog_id' => $blog_id, 'date_registered' => current_time('mysql')) );

}



/**

 * Get the remaining upload space for this blog.

 *

 * @since MU

 * @uses upload_is_user_over_quota()

 * @uses get_space_allowed()

 * @uses get_dirsize()

 *

 * @param int $size

 * @return int

 */

function fix_import_form_size( $size ) {

	if ( upload_is_user_over_quota( false ) == true )

		return 0;



	$spaceAllowed = 1024 * 1024 * get_space_allowed();

	$dirName = BLOGUPLOADDIR;

	$dirsize = get_dirsize($dirName) ;

	if ( $size > $spaceAllowed - $dirsize )

		return $spaceAllowed - $dirsize; // remaining space

	else

		return $size; // default

}



/**

 * Maintains a canonical list of terms by syncing terms created for each blog with the global terms table.

 *

 * @since 3.0.0

 *

 * @see term_id_filter

 *

 * @param int $term_id An ID for a term on the current blog.

 * @return int An ID from the global terms table mapped from $term_id.

 */

function global_terms( $term_id, $deprecated = '' ) {

	global $wpdb;

	static $global_terms_recurse = null;



	if ( !global_terms_enabled() )

		return $term_id;



	// prevent a race condition

	$recurse_start = false;

	if ( $global_terms_recurse === null ) {

		$recurse_start = true;

		$global_terms_recurse = 1;

	} elseif ( 10 < $global_terms_recurse++ ) {

		return $term_id;

	}



	$term_id = intval( $term_id );

	$c = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->terms WHERE term_id = %d", $term_id ) );



	$global_id = $wpdb->get_var( $wpdb->prepare( "SELECT cat_ID FROM $wpdb->sitecategories WHERE category_nicename = %s", $c->slug ) );

	if ( $global_id == null ) {

		$used_global_id = $wpdb->get_var( $wpdb->prepare( "SELECT cat_ID FROM $wpdb->sitecategories WHERE cat_ID = %d", $c->term_id ) );

		if ( null == $used_global_id ) {

			$wpdb->insert( $wpdb->sitecategories, array( 'cat_ID' => $term_id, 'cat_name' => $c->name, 'category_nicename' => $c->slug ) );

			$global_id = $wpdb->insert_id;

			if ( empty( $global_id ) )

				return $term_id;

		} else {

			$max_global_id = $wpdb->get_var( "SELECT MAX(cat_ID) FROM $wpdb->sitecategories" );

			$max_local_id = $wpdb->get_var( "SELECT MAX(term_id) FROM $wpdb->terms" );

			$new_global_id = max( $max_global_id, $max_local_id ) + mt_rand( 100, 400 );

			$wpdb->insert( $wpdb->sitecategories, array( 'cat_ID' => $new_global_id, 'cat_name' => $c->name, 'category_nicename' => $c->slug ) );

			$global_id = $wpdb->insert_id;

		}

	} elseif ( $global_id != $term_id ) {

		$local_id = $wpdb->get_row( $wpdb->prepare( "SELECT term_id FROM $wpdb->terms WHERE term_id = %d", $global_id ) );

		if ( null != $local_id )

			$local_id = global_terms( $local_id );

			if ( 10 < $global_terms_recurse )

				$global_id = $term_id;

	}



	if ( $global_id != $term_id ) {

		if ( get_option( 'default_category' ) == $term_id )

			update_option( 'default_category', $global_id );



		$wpdb->update( $wpdb->terms, array('term_id' => $global_id), array('term_id' => $term_id) );

		$wpdb->update( $wpdb->term_taxonomy, array('term_id' => $global_id), array('term_id' => $term_id) );

		$wpdb->update( $wpdb->term_taxonomy, array('parent' => $global_id), array('parent' => $term_id) );



		clean_term_cache($term_id);

	}

	if( $recurse_start )

		$global_terms_recurse = null;



	return $global_id;

}



/**

 * Ensure that the current site's domain is listed in the allowed redirect host list.

 *

 * @see wp_validate_redirect()

 * @since MU

 *

 * @return array The current site's domain

 */

function redirect_this_site( $deprecated = '' ) {

	global $current_site;

	return array( $current_site->domain );

}



/**

 * Check whether an upload is too big.

 *

 * @since MU

 *

 * @param array $upload

 * @return mixed If the upload is under the size limit, $upload is returned. Otherwise returns an error message.

 */

function upload_is_file_too_big( $upload ) {

	if ( is_array( $upload ) == false || defined( 'WP_IMPORTING' ) )

		return $upload;



	if ( strlen( $upload['bits'] )  > ( 1024 * get_site_option( 'fileupload_maxk', 1500 ) ) )

		return sprintf( __( 'This file is too big. Files must be less than %d KB in size.' ) . '<br />', get_site_option( 'fileupload_maxk', 1500 ));



	return $upload;

}



/**

 * Add a nonce field to the signup page.

 *

 * @since MU

 * @uses wp_nonce_field()

 */

function signup_nonce_fields() {

	$id = mt_rand();

	echo "<input type='hidden' name='signup_form_id' value='{$id}' />";

	wp_nonce_field('signup_form_' . $id, '_signup_form', false);

}



/**

 * Process the signup nonce created in signup_nonce_fields().

 *

 * @since MU

 * @uses wp_create_nonce()

 *

 * @param array $result

 * @return array

 */

function signup_nonce_check( $result ) {

	if ( !strpos( $_SERVER[ 'PHP_SELF' ], 'wp-signup.php' ) )

		return $result;



	if ( wp_create_nonce('signup_form_' . $_POST[ 'signup_form_id' ]) != $_POST['_signup_form'] )

		wp_die( __('Please try again!') );



	return $result;

}



/**

 * Correct 404 redirects when NOBLOGREDIRECT is defined.

 *

 * @since MU

 */

function maybe_redirect_404() {

	global $current_site;

	if ( is_main_site() && is_404() && defined( 'NOBLOGREDIRECT' ) && ( $destination = apply_filters( 'blog_redirect_404', NOBLOGREDIRECT ) ) ) {

		if ( $destination == '%siteurl%' )

			$destination = network_home_url();

		wp_redirect( $destination );

		exit();

	}

}



/**

 * Add a new user to a blog by visiting /newbloguser/username/.

 *

 * This will only work when the user's details are saved as an option

 * keyed as 'new_user_x', where 'x' is the username of the user to be

 * added, as when a user is invited through the regular WP Add User interface.

 *

 * @since MU

 * @uses add_existing_user_to_blog()

 */

function maybe_add_existing_user_to_blog() {

	if ( false === strpos( $_SERVER[ 'REQUEST_URI' ], '/newbloguser/' ) )

		return false;



	$parts = explode( '/', $_SERVER[ 'REQUEST_URI' ] );

	$key = array_pop( $parts );



	if ( $key == '' )

		$key = array_pop( $parts );



	$details = get_option( 'new_user_' . $key );

	if ( !empty( $details ) )

		delete_option( 'new_user_' . $key );



	if ( empty( $details ) || is_wp_error( add_existing_user_to_blog( $details ) ) )

		wp_die( sprintf(__('An error occurred adding you to this site. Back to the <a href="%s">homepage</a>.'), site_url() ) );



	wp_die( sprintf(__('You have been added to this site. Please visit the <a href="%s">homepage</a> or <a href="%s">login</a> using your username and password.'), site_url(), admin_url() ), __('Success') );

}



/**

 * Add a user to a blog based on details from maybe_add_existing_user_to_blog().

 *

 * @since MU

 * @uses add_user_to_blog()

 *

 * @param array $details

 */

function add_existing_user_to_blog( $details = false ) {

	global $blog_id;



	if ( is_array( $details ) ) {

		$result = add_user_to_blog( $blog_id, $details[ 'user_id' ], $details[ 'role' ] );

		do_action( 'added_existing_user', $details[ 'user_id' ], $result );

	}

	return $result;

}



/**

 * Add a newly created user to the appropriate blog

 *

 * @since MU

 *

 * @param int $user_id

 * @param string $email

 * @param array $meta

 */

function add_new_user_to_blog( $user_id, $email, $meta ) {

	global $current_site;

	if ( !empty( $meta[ 'add_to_blog' ] ) ) {

		$blog_id = $meta[ 'add_to_blog' ];

		$role = $meta[ 'new_role' ];

		remove_user_from_blog($user_id, $current_site->blog_id); // remove user from main blog.

		add_user_to_blog( $blog_id, $user_id, $role );

		update_user_meta( $user_id, 'primary_blog', $blog_id );

	}

}



/**

 * Correct From host on outgoing mail to match the site domain

 *

 * @since MU

 */

function fix_phpmailer_messageid( $phpmailer ) {

	global $current_site;

	$phpmailer->Hostname = $current_site->domain;

}



/**

 * Check to see whether a user is marked as a spammer, based on username

 *

 * @since MU

 * @uses get_current_user_id()

 * @uses get_user_id_from_string()

 *

 * @param string $username

 * @return bool

 */

function is_user_spammy( $username = 0 ) {

	if ( $username == 0 ) {

		$user_id = get_current_user_id();

	} else {

		$user_id = get_user_id_from_string( $username );

	}

	$u = new WP_User( $user_id );



	return ( isset( $u->spam ) && $u->spam == 1 );

}



/**

 * Update this blog's 'public' setting in the global blogs table.

 *

 * Public blogs have a setting of 1, private blogs are 0.

 *

 * @since MU

 * @uses update_blog_status()

 *

 * @param int $old_value

 * @param int $value The new public value

 * @return bool

 */

function update_blog_public( $old_value, $value ) {

	global $wpdb;

	do_action('update_blog_public');

	update_blog_status( $wpdb->blogid, 'public', (int) $value );

}

add_action('update_option_blog_public', 'update_blog_public', 10, 2);



/**

 * Get the "dashboard blog", the blog where users without a blog edit their profile data.

 *

 * @since MU

 * @uses get_blog_details()

 *

 * @return int

 */

function get_dashboard_blog() {

	if ( $blog = get_site_option( 'dashboard_blog' ) )

		return get_blog_details( $blog );



	return get_blog_details( $GLOBALS['current_site']->blog_id );

}



/**

 * Check whether a usermeta key has to do with the current blog.

 *

 * @since MU

 * @uses wp_get_current_user()

 *

 * @param string $key

 * @param int $user_id Optional. Defaults to current user.

 * @param int $blog_id Optional. Defaults to current blog.

 * @return bool

 */

function is_user_option_local( $key, $user_id = 0, $blog_id = 0 ) {

	global $wpdb;



	$current_user = wp_get_current_user();

	if ( $user_id == 0 )

		$user_id = $current_user->ID;

	if ( $blog_id == 0 )

		$blog_id = $wpdb->blogid;



	$local_key = $wpdb->base_prefix . $blog_id . '_' . $key;



	if ( isset( $current_user->$local_key ) )

		return true;



	return false;

}



/**

 * Check whether users can self-register, based on Network settings.

 *

 * @since MU

 *

 * @return bool

 */

function users_can_register_signup_filter() {

	$registration = get_site_option('registration');

	if ( $registration == 'all' || $registration == 'user' )

		return true;



	return false;

}

add_filter('option_users_can_register', 'users_can_register_signup_filter');



/**

 * Ensure that the welcome message is not empty. Currently unused.

 *

 * @since MU

 *

 * @param string $text

 * @return string

 */

function welcome_user_msg_filter( $text ) {

	if ( !$text ) {

		return __( 'Dear User,



Your new account is set up.



You can log in with the following information:

Username: USERNAME

Password: PASSWORD

LOGINLINK



Thanks!



--The Team @ SITE_NAME' );

	}

	return $text;

}

add_filter( 'site_option_welcome_user_email', 'welcome_user_msg_filter' );



/**

 * Whether to force SSL on content.

 *

 * @since 2.8.5

 *

 * @param string|bool $force

 * @return bool True if forced, false if not forced.

 */

function force_ssl_content( $force = '' ) {

	static $forced_content;



	if ( '' != $force ) {

		$old_forced = $forced_content;

		$forced_content = $force;

		return $old_forced;

	}



	return $forced_content;

}



/**

 * Formats an String URL to use HTTPS if HTTP is found.

 * Useful as a filter.

 *

 * @since 2.8.5

 **/

function filter_SSL( $url ) {

	if ( !is_string( $url ) )

		return get_bloginfo( 'url' ); //return home blog url with proper scheme



	$arrURL = parse_url( $url );



	if ( force_ssl_content() && is_ssl() ) {

		if ( 'http' === $arrURL['scheme'] && 'https' !== $arrURL['scheme'] )

			$url = str_replace( $arrURL['scheme'], 'https', $url );

	}



	return $url;

}



/**

 * Schedule update of the network-wide counts for the current network.

 *

 * @since 3.1.0

 */

function wp_schedule_update_network_counts() {

	if ( !is_main_site() )

		return;



	if ( !wp_next_scheduled('update_network_counts') && !defined('WP_INSTALLING') )

		wp_schedule_event(time(), 'twicedaily', 'update_network_counts');

}



/**

 *  Update the network-wide counts for the current network.

 *

 *  @since 3.1.0

 */

function wp_update_network_counts() {

	global $wpdb;



	$count = $wpdb->get_var( $wpdb->prepare("SELECT COUNT(blog_id) as c FROM $wpdb->blogs WHERE site_id = %d AND spam = '0' AND deleted = '0' and archived = '0'", $wpdb->siteid) );

	update_site_option( 'blog_count', $count );



	$count = $wpdb->get_var( $wpdb->prepare("SELECT COUNT(ID) as c FROM $wpdb->users WHERE spam = '0' AND deleted = '0'") );

	update_site_option( 'user_count', $count );

}



?>