WordPress/wp-includes/pluggable.php

<?php
/**
 * These functions can be replaced via plugins. If plugins do not redefine these
 * functions, then these will be used instead.
 *
 * @package WordPress
 */

if ( !function_exists('wp_set_current_user') ) :
/**
 * Changes the current user by ID or name.
 *
 * Set $id to null and specify a name if you do not know a user's ID.
 *
 * Some WordPress functionality is based on the current user and not based on
 * the signed in user. Therefore, it opens the ability to edit and perform
 * actions on users who aren't signed in.
 *
 * @since 2.0.3
 * @global object $current_user The current user object which holds the user data.
 *
 * @param int $id User ID
 * @param string $name User's username
 * @return WP_User Current user User object
 */
function wp_set_current_user($id, $name = '') {
	global $current_user;

	if ( isset( $current_user ) && ( $current_user instanceof WP_User ) && ( $id == $current_user->ID ) )
		return $current_user;

	$current_user = new WP_User( $id, $name );

	setup_userdata( $current_user->ID );

	/**
	 * Fires after the current user is set.
	 *
	 * @since 2.0.1
	 */
	do_action( 'set_current_user' );

	return $current_user;
}
endif;

if ( !function_exists('wp_get_current_user') ) :
/**
 * Retrieve the current user object.
 *
 * @since 2.0.3
 *
 * @return WP_User Current user WP_User object
 */
function wp_get_current_user() {
	global $current_user;

	get_currentuserinfo();

	return $current_user;
}
endif;

if ( !function_exists('get_currentuserinfo') ) :
/**
 * Populate global variables with information about the currently logged in user.
 *
 * Will set the current user, if the current user is not set. The current user
 * will be set to the logged-in person. If no user is logged-in, then it will
 * set the current user to 0, which is invalid and won't have any permissions.
 *
 * @since 0.71
 *
 * @uses $current_user Checks if the current user is set
 * @uses wp_validate_auth_cookie() Retrieves current logged in user.
 *
 * @return bool|null False on XML-RPC Request and invalid auth cookie. Null when current user set.
 */
function get_currentuserinfo() {
	global $current_user;

	if ( ! empty( $current_user ) ) {
		if ( $current_user instanceof WP_User )
			return;

		// Upgrade stdClass to WP_User
		if ( is_object( $current_user ) && isset( $current_user->ID ) ) {
			$cur_id = $current_user->ID;
			$current_user = null;
			wp_set_current_user( $cur_id );
			return;
		}

		// $current_user has a junk value. Force to WP_User with ID 0.
		$current_user = null;
		wp_set_current_user( 0 );
		return false;
	}

	if ( defined('XMLRPC_REQUEST') && XMLRPC_REQUEST ) {
		wp_set_current_user( 0 );
		return false;
	}

	/**
	 * Filter the current user.
	 *
	 * The default filters use this to determine the current user from the
	 * request's cookies, if available.
	 *
	 * Returning a value of false will effectively short-circuit setting
	 * the current user.
	 *
	 * @since 3.9.0
	 *
	 * @param int|bool $user_id User ID if one has been determined, false otherwise.
	 */
	$user_id = apply_filters( 'determine_current_user', false );
	if ( ! $user_id ) {
		wp_set_current_user( 0 );
		return false;
	}

	wp_set_current_user( $user_id );
}
endif;

if ( !function_exists('get_userdata') ) :
/**
 * Retrieve user info by user ID.
 *
 * @since 0.71
 *
 * @param int $user_id User ID
 * @return WP_User|bool WP_User object on success, false on failure.
 */
function get_userdata( $user_id ) {
	return get_user_by( 'id', $user_id );
}
endif;

if ( !function_exists('get_user_by') ) :
/**
 * Retrieve user info by a given field
 *
 * @since 2.8.0
 *
 * @param string $field The field to retrieve the user with. id | slug | email | login
 * @param int|string $value A value for $field. A user ID, slug, email address, or login name.
 * @return WP_User|bool WP_User object on success, false on failure.
 */
function get_user_by( $field, $value ) {
	$userdata = WP_User::get_data_by( $field, $value );

	if ( !$userdata )
		return false;

	$user = new WP_User;
	$user->init( $userdata );

	return $user;
}
endif;

if ( !function_exists('cache_users') ) :
/**
 * Retrieve info for user lists to prevent multiple queries by get_userdata()
 *
 * @since 3.0.0
 *
 * @param array $user_ids User ID numbers list
 */
function cache_users( $user_ids ) {
	global $wpdb;

	$clean = _get_non_cached_ids( $user_ids, 'users' );

	if ( empty( $clean ) )
		return;

	$list = implode( ',', $clean );

	$users = $wpdb->get_results( "SELECT * FROM $wpdb->users WHERE ID IN ($list)" );

	$ids = array();
	foreach ( $users as $user ) {
		update_user_caches( $user );
		$ids[] = $user->ID;
	}
	update_meta_cache( 'user', $ids );
}
endif;

if ( !function_exists( 'wp_mail' ) ) :
/**
 * Send mail, similar to PHP's mail
 *
 * A true return value does not automatically mean that the user received the
 * email successfully. It just only means that the method used was able to
 * process the request without any errors.
 *
 * Using the two 'wp_mail_from' and 'wp_mail_from_name' hooks allow from
 * creating a from address like 'Name <email@address.com>' when both are set. If
 * just 'wp_mail_from' is set, then just the email address will be used with no
 * name.
 *
 * The default content type is 'text/plain' which does not allow using HTML.
 * However, you can set the content type of the email by using the
 * 'wp_mail_content_type' filter.
 *
 * The default charset is based on the charset used on the blog. The charset can
 * be set using the 'wp_mail_charset' filter.
 *
 * @since 1.2.1
 *
 * @uses PHPMailer
 *
 * @param string|array $to Array or comma-separated list of email addresses to send message.
 * @param string $subject Email subject
 * @param string $message Message contents
 * @param string|array $headers Optional. Additional headers.
 * @param string|array $attachments Optional. Files to attach.
 * @return bool Whether the email contents were sent successfully.
 */
function wp_mail( $to, $subject, $message, $headers = '', $attachments = array() ) {
	// Compact the input, apply the filters, and extract them back out

	/**
	 * Filter the wp_mail() arguments.
	 *
	 * @since 2.2.0
	 *
	 * @param array $args A compacted array of wp_mail() arguments, including the "to" email,
	 *                    subject, message, headers, and attachments values.
	 */
	$atts = apply_filters( 'wp_mail', compact( 'to', 'subject', 'message', 'headers', 'attachments' ) );

	if ( isset( $atts['to'] ) ) {
		$to = $atts['to'];
	}

	if ( isset( $atts['subject'] ) ) {
		$subject = $atts['subject'];
	}

	if ( isset( $atts['message'] ) ) {
		$message = $atts['message'];
	}

	if ( isset( $atts['headers'] ) ) {
		$headers = $atts['headers'];
	}

	if ( isset( $atts['attachments'] ) ) {
		$attachments = $atts['attachments'];
	}

	if ( ! is_array( $attachments ) ) {
		$attachments = explode( "\n", str_replace( "\r\n", "\n", $attachments ) );
	}
	global $phpmailer;

	// (Re)create it, if it's gone missing
	if ( !is_object( $phpmailer ) || !is_a( $phpmailer, 'PHPMailer' ) ) {
		require_once ABSPATH . WPINC . '/class-phpmailer.php';
		require_once ABSPATH . WPINC . '/class-smtp.php';
		$phpmailer = new PHPMailer( true );
	}

	// Headers
	if ( empty( $headers ) ) {
		$headers = array();
	} else {
		if ( !is_array( $headers ) ) {
			// Explode the headers out, so this function can take both
			// string headers and an array of headers.
			$tempheaders = explode( "\n", str_replace( "\r\n", "\n", $headers ) );
		} else {
			$tempheaders = $headers;
		}
		$headers = array();
		$cc = array();
		$bcc = array();

		// If it's actually got contents
		if ( !empty( $tempheaders ) ) {
			// Iterate through the raw headers
			foreach ( (array) $tempheaders as $header ) {
				if ( strpos($header, ':') === false ) {
					if ( false !== stripos( $header, 'boundary=' ) ) {
						$parts = preg_split('/boundary=/i', trim( $header ) );
						$boundary = trim( str_replace( array( "'", '"' ), '', $parts[1] ) );
					}
					continue;
				}
				// Explode them out
				list( $name, $content ) = explode( ':', trim( $header ), 2 );

				// Cleanup crew
				$name    = trim( $name    );
				$content = trim( $content );

				switch ( strtolower( $name ) ) {
					// Mainly for legacy -- process a From: header if it's there
					case 'from':
						if ( strpos($content, '<' ) !== false ) {
							// So... making my life hard again?
							$from_name = substr( $content, 0, strpos( $content, '<' ) - 1 );
							$from_name = str_replace( '"', '', $from_name );
							$from_name = trim( $from_name );

							$from_email = substr( $content, strpos( $content, '<' ) + 1 );
							$from_email = str_replace( '>', '', $from_email );
							$from_email = trim( $from_email );
						} else {
							$from_email = trim( $content );
						}
						break;
					case 'content-type':
						if ( strpos( $content, ';' ) !== false ) {
							list( $type, $charset ) = explode( ';', $content );
							$content_type = trim( $type );
							if ( false !== stripos( $charset, 'charset=' ) ) {
								$charset = trim( str_replace( array( 'charset=', '"' ), '', $charset ) );
							} elseif ( false !== stripos( $charset, 'boundary=' ) ) {
								$boundary = trim( str_replace( array( 'BOUNDARY=', 'boundary=', '"' ), '', $charset ) );
								$charset = '';
							}
						} else {
							$content_type = trim( $content );
						}
						break;
					case 'cc':
						$cc = array_merge( (array) $cc, explode( ',', $content ) );
						break;
					case 'bcc':
						$bcc = array_merge( (array) $bcc, explode( ',', $content ) );
						break;
					default:
						// Add it to our grand headers array
						$headers[trim( $name )] = trim( $content );
						break;
				}
			}
		}
	}

	// Empty out the values that may be set
	$phpmailer->ClearAllRecipients();
	$phpmailer->ClearAttachments();
	$phpmailer->ClearCustomHeaders();
	$phpmailer->ClearReplyTos();

	// From email and name
	// If we don't have a name from the input headers
	if ( !isset( $from_name ) )
		$from_name = 'WordPress';

	/* If we don't have an email from the input headers default to wordpress@$sitename
	 * Some hosts will block outgoing mail from this address if it doesn't exist but
	 * there's no easy alternative. Defaulting to admin_email might appear to be another
	 * option but some hosts may refuse to relay mail from an unknown domain. See
	 * http://trac.wordpress.org/ticket/5007.
	 */

	if ( !isset( $from_email ) ) {
		// Get the site domain and get rid of www.
		$sitename = strtolower( $_SERVER['SERVER_NAME'] );
		if ( substr( $sitename, 0, 4 ) == 'www.' ) {
			$sitename = substr( $sitename, 4 );
		}

		$from_email = 'wordpress@' . $sitename;
	}

	/**
	 * Filter the email address to send from.
	 *
	 * @since 2.2.0
	 *
	 * @param string $from_email Email address to send from.
	 */
	$phpmailer->From = apply_filters( 'wp_mail_from', $from_email );

	/**
	 * Filter the name to associate with the "from" email address.
	 *
	 * @since 2.3.0
	 *
	 * @param string $from_name Name associated with the "from" email address.
	 */
	$phpmailer->FromName = apply_filters( 'wp_mail_from_name', $from_name );

	// Set destination addresses
	if ( !is_array( $to ) )
		$to = explode( ',', $to );

	foreach ( (array) $to as $recipient ) {
		try {
			// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
			$recipient_name = '';
			if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
				if ( count( $matches ) == 3 ) {
					$recipient_name = $matches[1];
					$recipient = $matches[2];
				}
			}
			$phpmailer->AddAddress( $recipient, $recipient_name);
		} catch ( phpmailerException $e ) {
			continue;
		}
	}

	// Set mail's subject and body
	$phpmailer->Subject = $subject;
	$phpmailer->Body    = $message;

	// Add any CC and BCC recipients
	if ( !empty( $cc ) ) {
		foreach ( (array) $cc as $recipient ) {
			try {
				// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
				$recipient_name = '';
				if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
					if ( count( $matches ) == 3 ) {
						$recipient_name = $matches[1];
						$recipient = $matches[2];
					}
				}
				$phpmailer->AddCc( $recipient, $recipient_name );
			} catch ( phpmailerException $e ) {
				continue;
			}
		}
	}

	if ( !empty( $bcc ) ) {
		foreach ( (array) $bcc as $recipient) {
			try {
				// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>"
				$recipient_name = '';
				if( preg_match( '/(.*)<(.+)>/', $recipient, $matches ) ) {
					if ( count( $matches ) == 3 ) {
						$recipient_name = $matches[1];
						$recipient = $matches[2];
					}
				}
				$phpmailer->AddBcc( $recipient, $recipient_name );
			} catch ( phpmailerException $e ) {
				continue;
			}
		}
	}

	// Set to use PHP's mail()
	$phpmailer->IsMail();

	// Set Content-Type and charset
	// If we don't have a content-type from the input headers
	if ( !isset( $content_type ) )
		$content_type = 'text/plain';

	/**
	 * Filter the wp_mail() content type.
	 *
	 * @since 2.3.0
	 *
	 * @param string $content_type Default wp_mail() content type.
	 */
	$content_type = apply_filters( 'wp_mail_content_type', $content_type );

	$phpmailer->ContentType = $content_type;

	// Set whether it's plaintext, depending on $content_type
	if ( 'text/html' == $content_type )
		$phpmailer->IsHTML( true );

	// If we don't have a charset from the input headers
	if ( !isset( $charset ) )
		$charset = get_bloginfo( 'charset' );

	// Set the content-type and charset

	/**
	 * Filter the default wp_mail() charset.
	 *
	 * @since 2.3.0
	 *
	 * @param string $charset Default email charset.
	 */
	$phpmailer->CharSet = apply_filters( 'wp_mail_charset', $charset );

	// Set custom headers
	if ( !empty( $headers ) ) {
		foreach( (array) $headers as $name => $content ) {
			$phpmailer->AddCustomHeader( sprintf( '%1$s: %2$s', $name, $content ) );
		}

		if ( false !== stripos( $content_type, 'multipart' ) && ! empty($boundary) )
			$phpmailer->AddCustomHeader( sprintf( "Content-Type: %s;\n\t boundary=\"%s\"", $content_type, $boundary ) );
	}

	if ( !empty( $attachments ) ) {
		foreach ( $attachments as $attachment ) {
			try {
				$phpmailer->AddAttachment($attachment);
			} catch ( phpmailerException $e ) {
				continue;
			}
		}
	}

	/**
	 * Fires after PHPMailer is initialized.
	 *
	 * @since 2.2.0
	 *
	 * @param PHPMailer &$phpmailer The PHPMailer instance, passed by reference.
	 */
	do_action_ref_array( 'phpmailer_init', array( &$phpmailer ) );

	// Send!
	try {
		return $phpmailer->Send();
	} catch ( phpmailerException $e ) {
		return false;
	}
}
endif;

if ( !function_exists('wp_authenticate') ) :
/**
 * Checks a user's login information and logs them in if it checks out.
 *
 * @since 2.5.0
 *
 * @param string $username User's username
 * @param string $password User's password
 * @return WP_User|WP_Error WP_User object if login successful, otherwise WP_Error object.
 */
function wp_authenticate($username, $password) {
	$username = sanitize_user($username);
	$password = trim($password);

	/**
	 * Filter the user to authenticate.
	 *
	 * If a non-null value is passed, the filter will effectively short-circuit
	 * authentication, returning an error instead.
	 *
	 * @since 2.8.0
	 *
	 * @param null|WP_User $user     User to authenticate.
	 * @param string       $username User login.
	 * @param string       $password User password
	 */
	$user = apply_filters( 'authenticate', null, $username, $password );

	if ( $user == null ) {
		// TODO what should the error message be? (Or would these even happen?)
		// Only needed if all authentication handlers fail to return anything.
		$user = new WP_Error('authentication_failed', __('<strong>ERROR</strong>: Invalid username or incorrect password.'));
	}

	$ignore_codes = array('empty_username', 'empty_password');

	if (is_wp_error($user) && !in_array($user->get_error_code(), $ignore_codes) ) {
		/**
		 * Fires after a user login has failed.
		 *
		 * @since 2.5.0
		 *
		 * @param string $username User login.
		 */
		do_action( 'wp_login_failed', $username );
	}

	return $user;
}
endif;

if ( !function_exists('wp_logout') ) :
/**
 * Log the current user out.
 *
 * @since 2.5.0
 */
function wp_logout() {
	wp_destroy_current_session();
	wp_clear_auth_cookie();

	/**
	 * Fires after a user is logged-out.
	 *
	 * @since 1.5.0
	 */
	do_action( 'wp_logout' );
}
endif;

if ( !function_exists('wp_validate_auth_cookie') ) :
/**
 * Validates authentication cookie.
 *
 * The checks include making sure that the authentication cookie is set and
 * pulling in the contents (if $cookie is not used).
 *
 * Makes sure the cookie is not expired. Verifies the hash in cookie is what is
 * should be and compares the two.
 *
 * @since 2.5.0
 *
 * @param string $cookie Optional. If used, will validate contents instead of cookie's
 * @param string $scheme Optional. The cookie scheme to use: auth, secure_auth, or logged_in
 * @return bool|int False if invalid cookie, User ID if valid.
 */
function wp_validate_auth_cookie($cookie = '', $scheme = '') {
	if ( ! $cookie_elements = wp_parse_auth_cookie($cookie, $scheme) ) {
		/**
		 * Fires if an authentication cookie is malformed.
		 *
		 * @since 2.7.0
		 *
		 * @param string $cookie Malformed auth cookie.
		 * @param string $scheme Authentication scheme. Values include 'auth', 'secure_auth',
		 *                       or 'logged_in'.
		 */
		do_action( 'auth_cookie_malformed', $cookie, $scheme );
		return false;
	}

	$scheme = $cookie_elements['scheme'];
	$username = $cookie_elements['username'];
	$hmac = $cookie_elements['hmac'];
	$token = $cookie_elements['token'];
	$expired = $expiration = $cookie_elements['expiration'];

	// Allow a grace period for POST and AJAX requests
	if ( defined('DOING_AJAX') || 'POST' == $_SERVER['REQUEST_METHOD'] ) {
		$expired += HOUR_IN_SECONDS;
	}

	// Quick check to see if an honest cookie has expired
	if ( $expired < time() ) {
		/**
		 * Fires once an authentication cookie has expired.
		 *
		 * @since 2.7.0
		 *
		 * @param array $cookie_elements An array of data for the authentication cookie.
		 */
		do_action( 'auth_cookie_expired', $cookie_elements );
		return false;
	}

	$user = get_user_by('login', $username);
	if ( ! $user ) {
		/**
		 * Fires if a bad username is entered in the user authentication process.
		 *
		 * @since 2.7.0
		 *
		 * @param array $cookie_elements An array of data for the authentication cookie.
		 */
		do_action( 'auth_cookie_bad_username', $cookie_elements );
		return false;
	}

	$pass_frag = substr($user->user_pass, 8, 4);

	$key = wp_hash( $username . '|' . $pass_frag . '|' . $expiration . '|' . $token, $scheme );
	$hash = hash_hmac( 'sha256', $username . '|' . $expiration . '|' . $token, $key );

	if ( ! hash_equals( $hash, $hmac ) ) {
		/**
		 * Fires if a bad authentication cookie hash is encountered.
		 *
		 * @since 2.7.0
		 *
		 * @param array $cookie_elements An array of data for the authentication cookie.
		 */
		do_action( 'auth_cookie_bad_hash', $cookie_elements );
		return false;
	}

	$manager = WP_Session_Tokens::get_instance( $user->ID );
	if ( ! $manager->verify_token( $token ) ) {
		do_action( 'auth_cookie_bad_session_token', $cookie_elements );
		return false;
	}

	// AJAX/POST grace period set above
	if ( $expiration < time() ) {
		$GLOBALS['login_grace_period'] = 1;
	}

	/**
	 * Fires once an authentication cookie has been validated.
	 *
	 * @since 2.7.0
	 *
	 * @param array   $cookie_elements An array of data for the authentication cookie.
	 * @param WP_User $user            User object.
	 */
	do_action( 'auth_cookie_valid', $cookie_elements, $user );

	return $user->ID;
}
endif;

if ( !function_exists('wp_generate_auth_cookie') ) :
/**
 * Generate authentication cookie contents.
 *
 * @since 2.5.0
 *
 * @param int $user_id User ID
 * @param int $expiration Cookie expiration in seconds
 * @param string $scheme Optional. The cookie scheme to use: auth, secure_auth, or logged_in
 * @param string $token User's session token to use for this cookie
 * @return string Authentication cookie contents. Empty string if user does not exist.
 */
function wp_generate_auth_cookie( $user_id, $expiration, $scheme = 'auth', $token = '' ) {
	$user = get_userdata($user_id);
	if ( ! $user ) {
		return '';
	}

	if ( ! $token ) {
		$manager = WP_Session_Tokens::get_instance( $user_id );
		$token = $manager->create_token( $expiration );
	}

	$pass_frag = substr($user->user_pass, 8, 4);

	$key = wp_hash( $user->user_login . '|' . $pass_frag . '|' . $expiration . '|' . $token, $scheme );
	$hash = hash_hmac( 'sha256', $user->user_login . '|' . $expiration . '|' . $token, $key );

	$cookie = $user->user_login . '|' . $expiration . '|' . $token . '|' . $hash;

	/**
	 * Filter the authentication cookie.
	 *
	 * @since 2.5.0
	 *
	 * @param string $cookie     Authentication cookie.
	 * @param int    $user_id    User ID.
	 * @param int    $expiration Authentication cookie expiration in seconds.
	 * @param string $scheme     Cookie scheme used. Accepts 'auth', 'secure_auth', or 'logged_in'.
	 * @param string $token      User's session token used.
	 */
	return apply_filters( 'auth_cookie', $cookie, $user_id, $expiration, $scheme, $token );
}
endif;

if ( !function_exists('wp_parse_auth_cookie') ) :
/**
 * Parse a cookie into its components
 *
 * @since 2.7.0
 *
 * @param string $cookie
 * @param string $scheme Optional. The cookie scheme to use: auth, secure_auth, or logged_in
 * @return array Authentication cookie components
 */
function wp_parse_auth_cookie($cookie = '', $scheme = '') {
	if ( empty($cookie) ) {
		switch ($scheme){
			case 'auth':
				$cookie_name = AUTH_COOKIE;
				break;
			case 'secure_auth':
				$cookie_name = SECURE_AUTH_COOKIE;
				break;
			case "logged_in":
				$cookie_name = LOGGED_IN_COOKIE;
				break;
			default:
				if ( is_ssl() ) {
					$cookie_name = SECURE_AUTH_COOKIE;
					$scheme = 'secure_auth';
				} else {
					$cookie_name = AUTH_COOKIE;
					$scheme = 'auth';
				}
	    }

		if ( empty($_COOKIE[$cookie_name]) )
			return false;
		$cookie = $_COOKIE[$cookie_name];
	}

	$cookie_elements = explode('|', $cookie);
	if ( count( $cookie_elements ) !== 4 ) {
		return false;
	}

	list( $username, $expiration, $token, $hmac ) = $cookie_elements;

	return compact( 'username', 'expiration', 'token', 'hmac', 'scheme' );
}
endif;

if ( !function_exists('wp_set_auth_cookie') ) :
/**
 * Sets the authentication cookies based on user ID.
 *
 * The $remember parameter increases the time that the cookie will be kept. The
 * default the cookie is kept without remembering is two days. When $remember is
 * set, the cookies will be kept for 14 days or two weeks.
 *
 * @since 2.5.0
 *
 * @param int $user_id User ID
 * @param bool $remember Whether to remember the user
 * @param mixed $secure  Whether the admin cookies should only be sent over HTTPS.
 *                       Default is_ssl().
 */
function wp_set_auth_cookie($user_id, $remember = false, $secure = '') {
	if ( $remember ) {
		/**
		 * Filter the duration of the authentication cookie expiration period.
		 *
		 * @since 2.8.0
		 *
		 * @param int  $length   Duration of the expiration period in seconds.
		 * @param int  $user_id  User ID.
		 * @param bool $remember Whether to remember the user login. Default false.
		 */
		$expiration = time() + apply_filters( 'auth_cookie_expiration', 14 * DAY_IN_SECONDS, $user_id, $remember );

		/*
		 * Ensure the browser will continue to send the cookie after the expiration time is reached.
		 * Needed for the login grace period in wp_validate_auth_cookie().
		 */
		$expire = $expiration + ( 12 * HOUR_IN_SECONDS );
	} else {
		/** This filter is documented in wp-includes/pluggable.php */
		$expiration = time() + apply_filters( 'auth_cookie_expiration', 2 * DAY_IN_SECONDS, $user_id, $remember );
		$expire = 0;
	}

	if ( '' === $secure ) {
		$secure = is_ssl();
	}

	// Frontend cookie is secure when the auth cookie is secure and the site's home URL is forced HTTPS.
	$secure_logged_in_cookie = $secure && 'https' === parse_url( get_option( 'home' ), PHP_URL_SCHEME );

	/**
	 * Filter whether the connection is secure.
	 *
	 * @since 3.1.0
	 *
	 * @param bool $secure  Whether the connection is secure.
	 * @param int  $user_id User ID.
	 */
	$secure = apply_filters( 'secure_auth_cookie', $secure, $user_id );

	/**
	 * Filter whether to use a secure cookie when logged-in.
	 *
	 * @since 3.1.0
	 *
	 * @param bool $secure_logged_in_cookie Whether to use a secure cookie when logged-in.
	 * @param int  $user_id                 User ID.
	 * @param bool $secure                  Whether the connection is secure.
	 */
	$secure_logged_in_cookie = apply_filters( 'secure_logged_in_cookie', $secure_logged_in_cookie, $user_id, $secure );

	if ( $secure ) {
		$auth_cookie_name = SECURE_AUTH_COOKIE;
		$scheme = 'secure_auth';
	} else {
		$auth_cookie_name = AUTH_COOKIE;
		$scheme = 'auth';
	}

	$manager = WP_Session_Tokens::get_instance( $user_id );
	$token = $manager->create_token( $expiration );

	$auth_cookie = wp_generate_auth_cookie( $user_id, $expiration, $scheme, $token );
	$logged_in_cookie = wp_generate_auth_cookie( $user_id, $expiration, 'logged_in', $token );

	/**
	 * Fires immediately before the authentication cookie is set.
	 *
	 * @since 2.5.0
	 *
	 * @param string $auth_cookie Authentication cookie.
	 * @param int    $expire      Login grace period in seconds. Default 43,200 seconds, or 12 hours.
	 * @param int    $expiration  Duration in seconds the authentication cookie should be valid.
	 *                            Default 1,209,600 seconds, or 14 days.
	 * @param int    $user_id     User ID.
	 * @param string $scheme      Authentication scheme. Values include 'auth', 'secure_auth', or 'logged_in'.
	 */
	do_action( 'set_auth_cookie', $auth_cookie, $expire, $expiration, $user_id, $scheme );

	/**
	 * Fires immediately before the secure authentication cookie is set.
	 *
	 * @since 2.6.0
	 *
	 * @param string $logged_in_cookie The logged-in cookie.
	 * @param int    $expire           Login grace period in seconds. Default 43,200 seconds, or 12 hours.
	 * @param int    $expiration       Duration in seconds the authentication cookie should be valid.
	 *                                 Default 1,209,600 seconds, or 14 days.
	 * @param int    $user_id          User ID.
	 * @param string $scheme           Authentication scheme. Default 'logged_in'.
	 */
	do_action( 'set_logged_in_cookie', $logged_in_cookie, $expire, $expiration, $user_id, 'logged_in' );

	setcookie($auth_cookie_name, $auth_cookie, $expire, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN, $secure, true);
	setcookie($auth_cookie_name, $auth_cookie, $expire, ADMIN_COOKIE_PATH, COOKIE_DOMAIN, $secure, true);
	setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, COOKIEPATH, COOKIE_DOMAIN, $secure_logged_in_cookie, true);
	if ( COOKIEPATH != SITECOOKIEPATH )
		setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, $secure_logged_in_cookie, true);
}
endif;

if ( !function_exists('wp_clear_auth_cookie') ) :
/**
 * Removes all of the cookies associated with authentication.
 *
 * @since 2.5.0
 */
function wp_clear_auth_cookie() {
	/**
	 * Fires just before the authentication cookies are cleared.
	 *
	 * @since 2.7.0
	 */
	do_action( 'clear_auth_cookie' );

	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH,   COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH,   COOKIE_DOMAIN );
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
	setcookie( LOGGED_IN_COOKIE,   ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,          COOKIE_DOMAIN );
	setcookie( LOGGED_IN_COOKIE,   ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH,      COOKIE_DOMAIN );

	// Old cookies
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

	// Even older cookies
	setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
	setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
}
endif;

if ( !function_exists('is_user_logged_in') ) :
/**
 * Checks if the current visitor is a logged in user.
 *
 * @since 2.0.0
 *
 * @return bool True if user is logged in, false if not logged in.
 */
function is_user_logged_in() {
	$user = wp_get_current_user();

	if ( ! $user->exists() )
		return false;

	return true;
}
endif;

if ( !function_exists('auth_redirect') ) :
/**
 * Checks if a user is logged in, if not it redirects them to the login page.
 *
 * @since 1.5.0
 */
function auth_redirect() {
	// Checks if a user is logged in, if not redirects them to the login page

	$secure = ( is_ssl() || force_ssl_admin() );

	/**
	 * Filter whether to use a secure authentication redirect.
	 *
	 * @since 3.1.0
	 *
	 * @param bool $secure Whether to use a secure authentication redirect. Default false.
	 */
	$secure = apply_filters( 'secure_auth_redirect', $secure );

	// If https is required and request is http, redirect
	if ( $secure && !is_ssl() && false !== strpos($_SERVER['REQUEST_URI'], 'wp-admin') ) {
		if ( 0 === strpos( $_SERVER['REQUEST_URI'], 'http' ) ) {
			wp_redirect( set_url_scheme( $_SERVER['REQUEST_URI'], 'https' ) );
			exit();
		} else {
			wp_redirect( 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
			exit();
		}
	}

	if ( is_user_admin() ) {
		$scheme = 'logged_in';
	} else {
		/**
		 * Filter the authentication redirect scheme.
		 *
		 * @since 2.9.0
		 *
		 * @param string $scheme Authentication redirect scheme. Default empty.
		 */
		$scheme = apply_filters( 'auth_redirect_scheme', '' );
	}

	if ( $user_id = wp_validate_auth_cookie( '',  $scheme) ) {
		/**
		 * Fires before the authentication redirect.
		 *
		 * @since 2.8.0
		 *
		 * @param int $user_id User ID.
		 */
		do_action( 'auth_redirect', $user_id );

		// If the user wants ssl but the session is not ssl, redirect.
		if ( !$secure && get_user_option('use_ssl', $user_id) && false !== strpos($_SERVER['REQUEST_URI'], 'wp-admin') ) {
			if ( 0 === strpos( $_SERVER['REQUEST_URI'], 'http' ) ) {
				wp_redirect( set_url_scheme( $_SERVER['REQUEST_URI'], 'https' ) );
				exit();
			} else {
				wp_redirect( 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
				exit();
			}
		}

		return;  // The cookie is good so we're done
	}

	// The cookie is no good so force login
	nocache_headers();

	$redirect = ( strpos( $_SERVER['REQUEST_URI'], '/options.php' ) && wp_get_referer() ) ? wp_get_referer() : set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );

	$login_url = wp_login_url($redirect, true);

	wp_redirect($login_url);
	exit();
}
endif;

if ( !function_exists('check_admin_referer') ) :
/**
 * Makes sure that a user was referred from another admin page.
 *
 * To avoid security exploits.
 *
 * @since 1.2.0
 *
 * @param string $action Action nonce
 * @param string $query_arg where to look for nonce in $_REQUEST (since 2.5)
 */
function check_admin_referer($action = -1, $query_arg = '_wpnonce') {
	if ( -1 == $action )
		_doing_it_wrong( __FUNCTION__, __( 'You should specify a nonce action to be verified by using the first parameter.' ), '3.2' );

	$adminurl = strtolower(admin_url());
	$referer = strtolower(wp_get_referer());
	$result = isset($_REQUEST[$query_arg]) ? wp_verify_nonce($_REQUEST[$query_arg], $action) : false;
	if ( !$result && !(-1 == $action && strpos($referer, $adminurl) === 0) ) {
		wp_nonce_ays($action);
		die();
	}

	/**
	 * Fires once the admin request has been validated or not.
	 *
	 * @since 1.5.1
	 *
	 * @param string $action The nonce action.
	 * @param bool   $result Whether the admin request nonce was validated.
	 */
	do_action( 'check_admin_referer', $action, $result );
	return $result;
}
endif;

if ( !function_exists('check_ajax_referer') ) :
/**
 * Verifies the AJAX request to prevent processing requests external of the blog.
 *
 * @since 2.0.3
 *
 * @param string $action Action nonce
 * @param string $query_arg where to look for nonce in $_REQUEST (since 2.5)
 */
function check_ajax_referer( $action = -1, $query_arg = false, $die = true ) {
	$nonce = '';

	if ( $query_arg && isset( $_REQUEST[ $query_arg ] ) )
		$nonce = $_REQUEST[ $query_arg ];
	elseif ( isset( $_REQUEST['_ajax_nonce'] ) )
		$nonce = $_REQUEST['_ajax_nonce'];
	elseif ( isset( $_REQUEST['_wpnonce'] ) )
		$nonce = $_REQUEST['_wpnonce'];

	$result = wp_verify_nonce( $nonce, $action );

	if ( $die && false == $result ) {
		if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
			wp_die( -1 );
		else
			die( '-1' );
	}

	/**
	 * Fires once the AJAX request has been validated or not.
	 *
	 * @since 2.1.0
	 *
	 * @param string $action The AJAX nonce action.
	 * @param bool   $result Whether the AJAX request nonce was validated.
	 */
	do_action( 'check_ajax_referer', $action, $result );

	return $result;
}
endif;

if ( !function_exists('wp_redirect') ) :
/**
 * Redirects to another page.
 *
 * @since 1.5.1
 *
 * @param string $location The path to redirect to.
 * @param int $status Status code to use.
 * @return bool False if $location is not provided, true otherwise.
 */
function wp_redirect($location, $status = 302) {
	global $is_IIS;

	/**
	 * Filter the redirect location.
	 *
	 * @since 2.1.0
	 *
	 * @param string $location The path to redirect to.
	 * @param int    $status   Status code to use.
	 */
	$location = apply_filters( 'wp_redirect', $location, $status );

	/**
	 * Filter the redirect status code.
	 *
	 * @since 2.3.0
	 *
	 * @param int    $status   Status code to use.
	 * @param string $location The path to redirect to.
	 */
	$status = apply_filters( 'wp_redirect_status', $status, $location );

	if ( ! $location )
		return false;

	$location = wp_sanitize_redirect($location);

	if ( !$is_IIS && php_sapi_name() != 'cgi-fcgi' )
		status_header($status); // This causes problems on IIS and some FastCGI setups

	header("Location: $location", true, $status);

	return true;
}
endif;

if ( !function_exists('wp_sanitize_redirect') ) :
/**
 * Sanitizes a URL for use in a redirect.
 *
 * @since 2.3.0
 *
 * @return string redirect-sanitized URL
 **/
function wp_sanitize_redirect($location) {
	$location = preg_replace('|[^a-z0-9-~+_.?#=&;,/:%!*]|i', '', $location);
	$location = wp_kses_no_null($location);

	// remove %0d and %0a from location
	$strip = array('%0d', '%0a', '%0D', '%0A');
	$location = _deep_replace($strip, $location);
	return $location;
}
endif;

if ( !function_exists('wp_safe_redirect') ) :
/**
 * Performs a safe (local) redirect, using wp_redirect().
 *
 * Checks whether the $location is using an allowed host, if it has an absolute
 * path. A plugin can therefore set or remove allowed host(s) to or from the
 * list.
 *
 * If the host is not allowed, then the redirect is to wp-admin on the siteurl
 * instead. This prevents malicious redirects which redirect to another host,
 * but only used in a few places.
 *
 * @since 2.3.0
 *
 * @uses wp_validate_redirect() To validate the redirect is to an allowed host.
 *
 * @return void Does not return anything
 **/
function wp_safe_redirect($location, $status = 302) {

	// Need to look at the URL the way it will end up in wp_redirect()
	$location = wp_sanitize_redirect($location);

	$location = wp_validate_redirect($location, admin_url());

	wp_redirect($location, $status);
}
endif;

if ( !function_exists('wp_validate_redirect') ) :
/**
 * Validates a URL for use in a redirect.
 *
 * Checks whether the $location is using an allowed host, if it has an absolute
 * path. A plugin can therefore set or remove allowed host(s) to or from the
 * list.
 *
 * If the host is not allowed, then the redirect is to $default supplied
 *
 * @since 2.8.1
 *
 * @param string $location The redirect to validate
 * @param string $default The value to return if $location is not allowed
 * @return string redirect-sanitized URL
 **/
function wp_validate_redirect($location, $default = '') {
	$location = trim( $location );
	// browsers will assume 'http' is your protocol, and will obey a redirect to a URL starting with '//'
	if ( substr($location, 0, 2) == '//' )
		$location = 'http:' . $location;

	// In php 5 parse_url may fail if the URL query part contains http://, bug #38143
	$test = ( $cut = strpos($location, '?') ) ? substr( $location, 0, $cut ) : $location;

	$lp  = parse_url($test);

	// Give up if malformed URL
	if ( false === $lp )
		return $default;

	// Allow only http and https schemes. No data:, etc.
	if ( isset($lp['scheme']) && !('http' == $lp['scheme'] || 'https' == $lp['scheme']) )
		return $default;

	// Reject if scheme is set but host is not. This catches urls like https:host.com for which parse_url does not set the host field.
	if ( isset($lp['scheme'])  && !isset($lp['host']) )
		return $default;

	$wpp = parse_url(home_url());

	/**
	 * Filter the whitelist of hosts to redirect to.
	 *
	 * @since 2.3.0
	 *
	 * @param array       $hosts An array of allowed hosts.
	 * @param bool|string $host  The parsed host; empty if not isset.
	 */
	$allowed_hosts = (array) apply_filters( 'allowed_redirect_hosts', array($wpp['host']), isset($lp['host']) ? $lp['host'] : '' );

	if ( isset($lp['host']) && ( !in_array($lp['host'], $allowed_hosts) && $lp['host'] != strtolower($wpp['host'])) )
		$location = $default;

	return $location;
}
endif;

if ( ! function_exists('wp_notify_postauthor') ) :
/**
 * Notify an author (and/or others) of a comment/trackback/pingback on a post.
 *
 * @since 1.0.0
 *
 * @param int $comment_id Comment ID
 * @param string $deprecated Not used
 * @return bool True on completion. False if no email addresses were specified.
 */
function wp_notify_postauthor( $comment_id, $deprecated = null ) {
	if ( null !== $deprecated ) {
		_deprecated_argument( __FUNCTION__, '3.8' );
	}

	$comment = get_comment( $comment_id );
	if ( empty( $comment ) )
		return false;

	$post    = get_post( $comment->comment_post_ID );
	$author  = get_userdata( $post->post_author );

	// Who to notify? By default, just the post author, but others can be added.
	$emails = array();
	if ( $author ) {
		$emails[] = $author->user_email;
	}

	/**
	 * Filter the list of email addresses to receive a comment notification.
	 *
	 * By default, only post authors are notified of comments. This filter allows
	 * others to be added.
	 *
	 * @since 3.7.0
	 *
	 * @param array $emails     An array of email addresses to receive a comment notification.
	 * @param int   $comment_id The comment ID.
	 */
	$emails = apply_filters( 'comment_notification_recipients', $emails, $comment_id );
	$emails = array_filter( $emails );

	// If there are no addresses to send the comment to, bail.
	if ( ! count( $emails ) ) {
		return false;
	}

	// Facilitate unsetting below without knowing the keys.
	$emails = array_flip( $emails );

	/**
	 * Filter whether to notify comment authors of their comments on their own posts.
	 *
	 * By default, comment authors aren't notified of their comments on their own
	 * posts. This filter allows you to override that.
	 *
	 * @since 3.8.0
	 *
	 * @param bool $notify     Whether to notify the post author of their own comment.
	 *                         Default false.
	 * @param int  $comment_id The comment ID.
	 */
	$notify_author = apply_filters( 'comment_notification_notify_author', false, $comment_id );

	// The comment was left by the author
	if ( $author && ! $notify_author && $comment->user_id == $post->post_author ) {
		unset( $emails[ $author->user_email ] );
	}

	// The author moderated a comment on their own post
	if ( $author && ! $notify_author && $post->post_author == get_current_user_id() ) {
		unset( $emails[ $author->user_email ] );
	}

	// The post author is no longer a member of the blog
	if ( $author && ! $notify_author && ! user_can( $post->post_author, 'read_post', $post->ID ) ) {
		unset( $emails[ $author->user_email ] );
	}

	// If there's no email to send the comment to, bail, otherwise flip array back around for use below
	if ( ! count( $emails ) ) {
		return false;
	} else {
		$emails = array_flip( $emails );
	}

	$comment_author_domain = @gethostbyaddr($comment->comment_author_IP);

	// The blogname option is escaped with esc_html on the way into the database in sanitize_option
	// we want to reverse this for the plain text arena of emails.
	$blogname = wp_specialchars_decode(get_option('blogname'), ENT_QUOTES);

	switch ( $comment->comment_type ) {
		case 'trackback':
			$notify_message  = sprintf( __( 'New trackback on your post "%s"' ), $post->post_title ) . "\r\n";
			/* translators: 1: website name, 2: author IP, 3: author domain */
			$notify_message .= sprintf( __('Website: %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= __('Excerpt: ') . "\r\n" . $comment->comment_content . "\r\n\r\n";
			$notify_message .= __('You can see all trackbacks on this post here: ') . "\r\n";
			/* translators: 1: blog name, 2: post title */
			$subject = sprintf( __('[%1$s] Trackback: "%2$s"'), $blogname, $post->post_title );
			break;
		case 'pingback':
			$notify_message  = sprintf( __( 'New pingback on your post "%s"' ), $post->post_title ) . "\r\n";
			/* translators: 1: comment author, 2: author IP, 3: author domain */
			$notify_message .= sprintf( __('Website: %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= __('Excerpt: ') . "\r\n" . sprintf('[...] %s [...]', $comment->comment_content ) . "\r\n\r\n";
			$notify_message .= __('You can see all pingbacks on this post here: ') . "\r\n";
			/* translators: 1: blog name, 2: post title */
			$subject = sprintf( __('[%1$s] Pingback: "%2$s"'), $blogname, $post->post_title );
			break;
		default: // Comments
			$notify_message  = sprintf( __( 'New comment on your post "%s"' ), $post->post_title ) . "\r\n";
			/* translators: 1: comment author, 2: author IP, 3: author domain */
			$notify_message .= sprintf( __('Author : %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('E-mail : %s'), $comment->comment_author_email ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= sprintf( __('Whois  : http://whois.arin.net/rest/ip/%s'), $comment->comment_author_IP ) . "\r\n";
			$notify_message .= __('Comment: ') . "\r\n" . $comment->comment_content . "\r\n\r\n";
			$notify_message .= __('You can see all comments on this post here: ') . "\r\n";
			/* translators: 1: blog name, 2: post title */
			$subject = sprintf( __('[%1$s] Comment: "%2$s"'), $blogname, $post->post_title );
			break;
	}
	$notify_message .= get_permalink($comment->comment_post_ID) . "#comments\r\n\r\n";
	$notify_message .= sprintf( __('Permalink: %s'), get_comment_link( $comment_id ) ) . "\r\n";

	if ( user_can( $post->post_author, 'edit_comment', $comment_id ) ) {
		if ( EMPTY_TRASH_DAYS )
			$notify_message .= sprintf( __('Trash it: %s'), admin_url("comment.php?action=trash&c=$comment_id") ) . "\r\n";
		else
			$notify_message .= sprintf( __('Delete it: %s'), admin_url("comment.php?action=delete&c=$comment_id") ) . "\r\n";
		$notify_message .= sprintf( __('Spam it: %s'), admin_url("comment.php?action=spam&c=$comment_id") ) . "\r\n";
	}

	$wp_email = 'wordpress@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME']));

	if ( '' == $comment->comment_author ) {
		$from = "From: \"$blogname\" <$wp_email>";
		if ( '' != $comment->comment_author_email )
			$reply_to = "Reply-To: $comment->comment_author_email";
	} else {
		$from = "From: \"$comment->comment_author\" <$wp_email>";
		if ( '' != $comment->comment_author_email )
			$reply_to = "Reply-To: \"$comment->comment_author_email\" <$comment->comment_author_email>";
	}

	$message_headers = "$from\n"
		. "Content-Type: text/plain; charset=\"" . get_option('blog_charset') . "\"\n";

	if ( isset($reply_to) )
		$message_headers .= $reply_to . "\n";

	/**
	 * Filter the comment notification email text.
	 *
	 * @since 1.5.2
	 *
	 * @param string $notify_message The comment notification email text.
	 * @param int    $comment_id     Comment ID.
	 */
	$notify_message = apply_filters( 'comment_notification_text', $notify_message, $comment_id );

	/**
	 * Filter the comment notification email subject.
	 *
	 * @since 1.5.2
	 *
	 * @param string $subject    The comment notification email subject.
	 * @param int    $comment_id Comment ID.
	 */
	$subject = apply_filters( 'comment_notification_subject', $subject, $comment_id );

	/**
	 * Filter the comment notification email headers.
	 *
	 * @since 1.5.2
	 *
	 * @param string $message_headers Headers for the comment notification email.
	 * @param int    $comment_id      Comment ID.
	 */
	$message_headers = apply_filters( 'comment_notification_headers', $message_headers, $comment_id );

	foreach ( $emails as $email ) {
		@wp_mail( $email, wp_specialchars_decode( $subject ), $notify_message, $message_headers );
	}

	return true;
}
endif;

if ( !function_exists('wp_notify_moderator') ) :
/**
 * Notifies the moderator of the blog about a new comment that is awaiting approval.
 *
 * @since 1.0.0
 *
 * @uses $wpdb
 *
 * @param int $comment_id Comment ID
 * @return bool Always returns true
 */
function wp_notify_moderator($comment_id) {
	global $wpdb;

	if ( 0 == get_option( 'moderation_notify' ) )
		return true;

	$comment = get_comment($comment_id);
	$post = get_post($comment->comment_post_ID);
	$user = get_userdata( $post->post_author );
	// Send to the administration and to the post author if the author can modify the comment.
	$emails = array( get_option( 'admin_email' ) );
	if ( user_can( $user->ID, 'edit_comment', $comment_id ) && ! empty( $user->user_email ) ) {
		if ( 0 !== strcasecmp( $user->user_email, get_option( 'admin_email' ) ) )
			$emails[] = $user->user_email;
	}

	$comment_author_domain = @gethostbyaddr($comment->comment_author_IP);
	$comments_waiting = $wpdb->get_var("SELECT count(comment_ID) FROM $wpdb->comments WHERE comment_approved = '0'");

	// The blogname option is escaped with esc_html on the way into the database in sanitize_option
	// we want to reverse this for the plain text arena of emails.
	$blogname = wp_specialchars_decode(get_option('blogname'), ENT_QUOTES);

	switch ( $comment->comment_type ) {
		case 'trackback':
			$notify_message  = sprintf( __('A new trackback on the post "%s" is waiting for your approval'), $post->post_title ) . "\r\n";
			$notify_message .= get_permalink($comment->comment_post_ID) . "\r\n\r\n";
			$notify_message .= sprintf( __('Website : %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= __('Trackback excerpt: ') . "\r\n" . $comment->comment_content . "\r\n\r\n";
			break;
		case 'pingback':
			$notify_message  = sprintf( __('A new pingback on the post "%s" is waiting for your approval'), $post->post_title ) . "\r\n";
			$notify_message .= get_permalink($comment->comment_post_ID) . "\r\n\r\n";
			$notify_message .= sprintf( __('Website : %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= __('Pingback excerpt: ') . "\r\n" . $comment->comment_content . "\r\n\r\n";
			break;
		default: // Comments
			$notify_message  = sprintf( __('A new comment on the post "%s" is waiting for your approval'), $post->post_title ) . "\r\n";
			$notify_message .= get_permalink($comment->comment_post_ID) . "\r\n\r\n";
			$notify_message .= sprintf( __('Author : %1$s (IP: %2$s , %3$s)'), $comment->comment_author, $comment->comment_author_IP, $comment_author_domain ) . "\r\n";
			$notify_message .= sprintf( __('E-mail : %s'), $comment->comment_author_email ) . "\r\n";
			$notify_message .= sprintf( __('URL    : %s'), $comment->comment_author_url ) . "\r\n";
			$notify_message .= sprintf( __('Whois  : http://whois.arin.net/rest/ip/%s'), $comment->comment_author_IP ) . "\r\n";
			$notify_message .= __('Comment: ') . "\r\n" . $comment->comment_content . "\r\n\r\n";
			break;
	}

	$notify_message .= sprintf( __('Approve it: %s'),  admin_url("comment.php?action=approve&c=$comment_id") ) . "\r\n";
	if ( EMPTY_TRASH_DAYS )
		$notify_message .= sprintf( __('Trash it: %s'), admin_url("comment.php?action=trash&c=$comment_id") ) . "\r\n";
	else
		$notify_message .= sprintf( __('Delete it: %s'), admin_url("comment.php?action=delete&c=$comment_id") ) . "\r\n";
	$notify_message .= sprintf( __('Spam it: %s'), admin_url("comment.php?action=spam&c=$comment_id") ) . "\r\n";

	$notify_message .= sprintf( _n('Currently %s comment is waiting for approval. Please visit the moderation panel:',
 		'Currently %s comments are waiting for approval. Please visit the moderation panel:', $comments_waiting), number_format_i18n($comments_waiting) ) . "\r\n";
	$notify_message .= admin_url("edit-comments.php?comment_status=moderated") . "\r\n";

	$subject = sprintf( __('[%1$s] Please moderate: "%2$s"'), $blogname, $post->post_title );
	$message_headers = '';

	/**
	 * Filter the list of recipients for comment moderation emails.
	 *
	 * @since 3.7.0
	 *
	 * @param array $emails     List of email addresses to notify for comment moderation.
	 * @param int   $comment_id Comment ID.
	 */
	$emails = apply_filters( 'comment_moderation_recipients', $emails, $comment_id );

	/**
	 * Filter the comment moderation email text.
	 *
	 * @since 1.5.2
	 *
	 * @param string $notify_message Text of the comment moderation email.
	 * @param int    $comment_id     Comment ID.
	 */
	$notify_message = apply_filters( 'comment_moderation_text', $notify_message, $comment_id );

	/**
	 * Filter the comment moderation email subject.
	 *
	 * @since 1.5.2
	 *
	 * @param string $subject    Subject of the comment moderation email.
	 * @param int    $comment_id Comment ID.
	 */
	$subject = apply_filters( 'comment_moderation_subject', $subject, $comment_id );

	/**
	 * Filter the comment moderation email headers.
	 *
	 * @since 2.8.0
	 *
	 * @param string $message_headers Headers for the comment moderation email.
	 * @param int    $comment_id      Comment ID.
	 */
	$message_headers = apply_filters( 'comment_moderation_headers', $message_headers, $comment_id );

	foreach ( $emails as $email ) {
		@wp_mail( $email, wp_specialchars_decode( $subject ), $notify_message, $message_headers );
	}

	return true;
}
endif;

if ( !function_exists('wp_password_change_notification') ) :
/**
 * Notify the blog admin of a user changing password, normally via email.
 *
 * @since 2.7.0
 *
 * @param object $user User Object
 */
function wp_password_change_notification(&$user) {
	// send a copy of password change notification to the admin
	// but check to see if it's the admin whose password we're changing, and skip this
	if ( 0 !== strcasecmp( $user->user_email, get_option( 'admin_email' ) ) ) {
		$message = sprintf(__('Password Lost and Changed for user: %s'), $user->user_login) . "\r\n";
		// The blogname option is escaped with esc_html on the way into the database in sanitize_option
		// we want to reverse this for the plain text arena of emails.
		$blogname = wp_specialchars_decode(get_option('blogname'), ENT_QUOTES);
		wp_mail(get_option('admin_email'), sprintf(__('[%s] Password Lost/Changed'), $blogname), $message);
	}
}
endif;

if ( !function_exists('wp_new_user_notification') ) :
/**
 * Email login credentials to a newly-registered user.
 *
 * A new user registration notification is also sent to admin email.
 *
 * @since 2.0.0
 *
 * @param int    $user_id        User ID.
 * @param string $plaintext_pass Optional. The user's plaintext password. Default empty.
 */
function wp_new_user_notification($user_id, $plaintext_pass = '') {
	$user = get_userdata( $user_id );

	// The blogname option is escaped with esc_html on the way into the database in sanitize_option
	// we want to reverse this for the plain text arena of emails.
	$blogname = wp_specialchars_decode(get_option('blogname'), ENT_QUOTES);

	$message  = sprintf(__('New user registration on your site %s:'), $blogname) . "\r\n\r\n";
	$message .= sprintf(__('Username: %s'), $user->user_login) . "\r\n\r\n";
	$message .= sprintf(__('E-mail: %s'), $user->user_email) . "\r\n";

	@wp_mail(get_option('admin_email'), sprintf(__('[%s] New User Registration'), $blogname), $message);

	if ( empty($plaintext_pass) )
		return;

	$message  = sprintf(__('Username: %s'), $user->user_login) . "\r\n";
	$message .= sprintf(__('Password: %s'), $plaintext_pass) . "\r\n";
	$message .= wp_login_url() . "\r\n";

	wp_mail($user->user_email, sprintf(__('[%s] Your username and password'), $blogname), $message);

}
endif;

if ( !function_exists('wp_nonce_tick') ) :
/**
 * Get the time-dependent variable for nonce creation.
 *
 * A nonce has a lifespan of two ticks. Nonces in their second tick may be
 * updated, e.g. by autosave.
 *
 * @since 2.5.0
 *
 * @return int
 */
function wp_nonce_tick() {
	/**
	 * Filter the lifespan of nonces in seconds.
	 *
	 * @since 2.5.0
	 *
	 * @param int $lifespan Lifespan of nonces in seconds. Default 86,400 seconds, or one day.
	 */
	$nonce_life = apply_filters( 'nonce_life', DAY_IN_SECONDS );

	return ceil(time() / ( $nonce_life / 2 ));
}
endif;

if ( !function_exists('wp_verify_nonce') ) :
/**
 * Verify that correct nonce was used with time limit.
 *
 * The user is given an amount of time to use the token, so therefore, since the
 * UID and $action remain the same, the independent variable is the time.
 *
 * @since 2.0.3
 *
 * @param string $nonce Nonce that was used in the form to verify
 * @param string|int $action Should give context to what is taking place and be the same when nonce was created.
 * @return bool Whether the nonce check passed or failed.
 */
function wp_verify_nonce($nonce, $action = -1) {
	$user = wp_get_current_user();
	$uid = (int) $user->ID;
	if ( ! $uid ) {
		/**
		 * Filter whether the user who generated the nonce is logged out.
		 *
		 * @since 3.5.0
		 *
		 * @param int    $uid    ID of the nonce-owning user.
		 * @param string $action The nonce action.
		 */
		$uid = apply_filters( 'nonce_user_logged_out', $uid, $action );
	}

	$token = wp_get_session_token();
	$i = wp_nonce_tick();

	// Nonce generated 0-12 hours ago
	$expected = substr( wp_hash( $i . '|' . $action . '|' . $uid . '|' . $token, 'nonce'), -12, 10 );
	if ( hash_equals( $expected, $nonce ) ) {
		return 1;
	}

	// Nonce generated 12-24 hours ago
	$expected = substr( wp_hash( ( $i - 1 ) . '|' . $action . '|' . $uid . '|' . $token, 'nonce' ), -12, 10 );
	if ( hash_equals( $expected, $nonce ) ) {
		return 2;
	}

	// Invalid nonce
	return false;
}
endif;

if ( !function_exists('wp_create_nonce') ) :
/**
 * Creates a cryptographic token tied to a specific action, user, and window of time.
 *
 * @since 2.0.3
 *
 * @param string $action Scalar value to add context to the nonce.
 * @return string The token.
 */
function wp_create_nonce($action = -1) {
	$user = wp_get_current_user();
	$uid = (int) $user->ID;
	if ( ! $uid ) {
		/** This filter is documented in wp-includes/pluggable.php */
		$uid = apply_filters( 'nonce_user_logged_out', $uid, $action );
	}

	$token = wp_get_session_token();
	$i = wp_nonce_tick();

	return substr( wp_hash( $i . '|' . $action . '|' . $uid . '|' . $token, 'nonce' ), -12, 10 );
}
endif;

if ( !function_exists('wp_salt') ) :
/**
 * Get salt to add to hashes.
 *
 * Salts are created using secret keys. Secret keys are located in two places:
 * in the database and in the wp-config.php file. The secret key in the database
 * is randomly generated and will be appended to the secret keys in wp-config.php.
 *
 * The secret keys in wp-config.php should be updated to strong, random keys to maximize
 * security. Below is an example of how the secret key constants are defined.
 * Do not paste this example directly into wp-config.php. Instead, have a
 * {@link https://api.wordpress.org/secret-key/1.1/salt/ secret key created} just
 * for you.
 *
 * <code>
 * define('AUTH_KEY',         ' Xakm<o xQy rw4EMsLKM-?!T+,PFF})H4lzcW57AF0U@N@< >M%G4Yt>f`z]MON');
 * define('SECURE_AUTH_KEY',  'LzJ}op]mr|6+![P}Ak:uNdJCJZd>(Hx.-Mh#Tz)pCIU#uGEnfFz|f ;;eU%/U^O~');
 * define('LOGGED_IN_KEY',    '|i|Ux`9<p-h$aFf(qnT:sDO:D1P^wZ$$/Ra@miTJi9G;ddp_<q}6H1)o|a +&JCM');
 * define('NONCE_KEY',        '%:R{[P|,s.KuMltH5}cI;/k<Gx~j!f0I)m_sIyu+&NJZ)-iO>z7X>QYR0Z_XnZ@|');
 * define('AUTH_SALT',        'eZyT)-Naw]F8CwA*VaW#q*|.)g@o}||wf~@C-YSt}(dh_r6EbI#A,y|nU2{B#JBW');
 * define('SECURE_AUTH_SALT', '!=oLUTXh,QW=H `}`L|9/^4-3 STz},T(w}W<I`.JjPi)<Bmf1v,HpGe}T1:Xt7n');
 * define('LOGGED_IN_SALT',   '+XSqHc;@Q*K_b|Z?NC[3H!!EONbh.n<+=uKR:>*c(u`g~EJBf#8u#R{mUEZrozmm');
 * define('NONCE_SALT',       'h`GXHhD>SLWVfg1(1(N{;.V!MoE(SfbA_ksP@&`+AycHcAV$+?@3q+rxV{%^VyKT');
 * </code>
 *
 * Salting passwords helps against tools which has stored hashed values of
 * common dictionary strings. The added values makes it harder to crack.
 *
 * @since 2.5.0
 *
 * @link https://api.wordpress.org/secret-key/1.1/salt/ Create secrets for wp-config.php
 *
 * @param string $scheme Authentication scheme (auth, secure_auth, logged_in, nonce)
 * @return string Salt value
 */
function wp_salt( $scheme = 'auth' ) {
	static $cached_salts = array();
	if ( isset( $cached_salts[ $scheme ] ) ) {
		/**
		 * Filter the WordPress salt.
		 *
		 * @since 2.5.0
		 *
		 * @param string $cached_salt Cached salt for the given scheme.
		 * @param string $scheme      Authentication scheme. Values include 'auth',
		 *                            'secure_auth', 'logged_in', and 'nonce'.
		 */
		return apply_filters( 'salt', $cached_salts[ $scheme ], $scheme );
	}

	static $duplicated_keys;
	if ( null === $duplicated_keys ) {
		$duplicated_keys = array( 'put your unique phrase here' => true );
		foreach ( array( 'AUTH', 'SECURE_AUTH', 'LOGGED_IN', 'NONCE', 'SECRET' ) as $first ) {
			foreach ( array( 'KEY', 'SALT' ) as $second ) {
				if ( ! defined( "{$first}_{$second}" ) ) {
					continue;
				}
				$value = constant( "{$first}_{$second}" );
				$duplicated_keys[ $value ] = isset( $duplicated_keys[ $value ] );
			}
		}
	}

	$values = array(
		'key' => '',
		'salt' => ''
	);
	if ( defined( 'SECRET_KEY' ) && SECRET_KEY && empty( $duplicated_keys[ SECRET_KEY ] ) ) {
		$values['key'] = SECRET_KEY;
	}
	if ( 'auth' == $scheme && defined( 'SECRET_SALT' ) && SECRET_SALT && empty( $duplicated_keys[ SECRET_SALT ] ) ) {
		$values['salt'] = SECRET_SALT;
	}

	if ( in_array( $scheme, array( 'auth', 'secure_auth', 'logged_in', 'nonce' ) ) ) {
		foreach ( array( 'key', 'salt' ) as $type ) {
			$const = strtoupper( "{$scheme}_{$type}" );
			if ( defined( $const ) && constant( $const ) && empty( $duplicated_keys[ constant( $const ) ] ) ) {
				$values[ $type ] = constant( $const );
			} elseif ( ! $values[ $type ] ) {
				$values[ $type ] = get_site_option( "{$scheme}_{$type}" );
				if ( ! $values[ $type ] ) {
					$values[ $type ] = wp_generate_password( 64, true, true );
					update_site_option( "{$scheme}_{$type}", $values[ $type ] );
				}
			}
		}
	} else {
		if ( ! $values['key'] ) {
			$values['key'] = get_site_option( 'secret_key' );
			if ( ! $values['key'] ) {
				$values['key'] = wp_generate_password( 64, true, true );
				update_site_option( 'secret_key', $values['key'] );
			}
		}
		$values['salt'] = hash_hmac( 'md5', $scheme, $values['key'] );
	}

	$cached_salts[ $scheme ] = $values['key'] . $values['salt'];

	/** This filter is documented in wp-includes/pluggable.php */
	return apply_filters( 'salt', $cached_salts[ $scheme ], $scheme );
}
endif;

if ( !function_exists('wp_hash') ) :
/**
 * Get hash of given string.
 *
 * @since 2.0.3
 * @uses wp_salt() Get WordPress salt
 *
 * @param string $data Plain text to hash
 * @return string Hash of $data
 */
function wp_hash($data, $scheme = 'auth') {
	$salt = wp_salt($scheme);

	return hash_hmac('md5', $data, $salt);
}
endif;

if ( !function_exists('wp_hash_password') ) :
/**
 * Create a hash (encrypt) of a plain text password.
 *
 * For integration with other applications, this function can be overwritten to
 * instead use the other package password checking algorithm.
 *
 * @since 2.5.0
 *
 * @global object $wp_hasher PHPass object
 * @uses PasswordHash::HashPassword
 *
 * @param string $password Plain text user password to hash
 * @return string The hash string of the password
 */
function wp_hash_password($password) {
	global $wp_hasher;

	if ( empty($wp_hasher) ) {
		require_once( ABSPATH . WPINC . '/class-phpass.php');
		// By default, use the portable hash from phpass
		$wp_hasher = new PasswordHash(8, true);
	}

	return $wp_hasher->HashPassword( trim( $password ) );
}
endif;

if ( !function_exists('wp_check_password') ) :
/**
 * Checks the plaintext password against the encrypted Password.
 *
 * Maintains compatibility between old version and the new cookie authentication
 * protocol using PHPass library. The $hash parameter is the encrypted password
 * and the function compares the plain text password when encrypted similarly
 * against the already encrypted password to see if they match.
 *
 * For integration with other applications, this function can be overwritten to
 * instead use the other package password checking algorithm.
 *
 * @since 2.5.0
 *
 * @global object $wp_hasher PHPass object used for checking the password
 *	against the $hash + $password
 * @uses PasswordHash::CheckPassword
 *
 * @param string $password Plaintext user's password
 * @param string $hash Hash of the user's password to check against.
 * @return bool False, if the $password does not match the hashed password
 */
function wp_check_password($password, $hash, $user_id = '') {
	global $wp_hasher;

	// If the hash is still md5...
	if ( strlen($hash) <= 32 ) {
		$check = ( $hash == md5($password) );
		if ( $check && $user_id ) {
			// Rehash using new hash.
			wp_set_password($password, $user_id);
			$hash = wp_hash_password($password);
		}

		/**
		 * Filter whether the plaintext password matches the encrypted password.
		 *
		 * @since 2.5.0
		 *
		 * @param bool   $check   Whether the passwords match.
		 * @param string $hash    The hashed password.
		 * @param int    $user_id User ID.
		 */
		return apply_filters( 'check_password', $check, $password, $hash, $user_id );
	}

	// If the stored hash is longer than an MD5, presume the
	// new style phpass portable hash.
	if ( empty($wp_hasher) ) {
		require_once( ABSPATH . WPINC . '/class-phpass.php');
		// By default, use the portable hash from phpass
		$wp_hasher = new PasswordHash(8, true);
	}

	$check = $wp_hasher->CheckPassword($password, $hash);

	/** This filter is documented in wp-includes/pluggable.php */
	return apply_filters( 'check_password', $check, $password, $hash, $user_id );
}
endif;

if ( !function_exists('wp_generate_password') ) :
/**
 * Generates a random password drawn from the defined set of characters.
 *
 * @since 2.5.0
 *
 * @param int $length The length of password to generate
 * @param bool $special_chars Whether to include standard special characters. Default true.
 * @param bool $extra_special_chars Whether to include other special characters. Used when
 *   generating secret keys and salts. Default false.
 * @return string The random password
 **/
function wp_generate_password( $length = 12, $special_chars = true, $extra_special_chars = false ) {
	$chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
	if ( $special_chars )
		$chars .= '!@#$%^&*()';
	if ( $extra_special_chars )
		$chars .= '-_ []{}<>~`+=,.;:/?|';

	$password = '';
	for ( $i = 0; $i < $length; $i++ ) {
		$password .= substr($chars, wp_rand(0, strlen($chars) - 1), 1);
	}

	/**
	 * Filter the randomly-generated password.
	 *
	 * @since 3.0.0
	 *
	 * @param string $password The generated password.
	 */
	return apply_filters( 'random_password', $password );
}
endif;

if ( !function_exists('wp_rand') ) :
/**
 * Generates a random number
 *
 * @since 2.6.2
 *
 * @param int $min Lower limit for the generated number
 * @param int $max Upper limit for the generated number
 * @return int A random number between min and max
 */
function wp_rand( $min = 0, $max = 0 ) {
	global $rnd_value;

	// Reset $rnd_value after 14 uses
	// 32(md5) + 40(sha1) + 40(sha1) / 8 = 14 random numbers from $rnd_value
	if ( strlen($rnd_value) < 8 ) {
		if ( defined( 'WP_SETUP_CONFIG' ) )
			static $seed = '';
		else
			$seed = get_transient('random_seed');
		$rnd_value = md5( uniqid(microtime() . mt_rand(), true ) . $seed );
		$rnd_value .= sha1($rnd_value);
		$rnd_value .= sha1($rnd_value . $seed);
		$seed = md5($seed . $rnd_value);
		if ( ! defined( 'WP_SETUP_CONFIG' ) )
			set_transient('random_seed', $seed);
	}

	// Take the first 8 digits for our value
	$value = substr($rnd_value, 0, 8);

	// Strip the first eight, leaving the remainder for the next call to wp_rand().
	$rnd_value = substr($rnd_value, 8);

	$value = abs(hexdec($value));

	// Some misconfigured 32bit environments (Entropy PHP, for example) truncate integers larger than PHP_INT_MAX to PHP_INT_MAX rather than overflowing them to floats.
	$max_random_number = 3000000000 === 2147483647 ? (float) "4294967295" : 4294967295; // 4294967295 = 0xffffffff

	// Reduce the value to be within the min - max range
	if ( $max != 0 )
		$value = $min + ( $max - $min + 1 ) * $value / ( $max_random_number + 1 );

	return abs(intval($value));
}
endif;

if ( !function_exists('wp_set_password') ) :
/**
 * Updates the user's password with a new encrypted one.
 *
 * For integration with other applications, this function can be overwritten to
 * instead use the other package password checking algorithm.
 *
 * Please note: This function should be used sparingly and is really only meant for single-time
 * application. Leveraging this improperly in a plugin or theme could result in an endless loop
 * of password resets if precautions are not taken to ensure it does not execute on every page load.
 *
 * @since 2.5.0
 *
 * @uses $wpdb WordPress database object for queries
 * @uses wp_hash_password() Used to encrypt the user's password before passing to the database
 *
 * @param string $password The plaintext new user password
 * @param int $user_id User ID
 */
function wp_set_password( $password, $user_id ) {
	global $wpdb;

	$hash = wp_hash_password( $password );
	$wpdb->update($wpdb->users, array('user_pass' => $hash, 'user_activation_key' => ''), array('ID' => $user_id) );

	wp_cache_delete($user_id, 'users');
}
endif;

if ( !function_exists( 'get_avatar' ) ) :
/**
 * Retrieve the avatar for a user who provided a user ID or email address.
 *
 * @since 2.5.0
 *
 * @param int|string|object $id_or_email A user ID,  email address, or comment object
 * @param int $size Size of the avatar image
 * @param string $default URL to a default image to use if no avatar is available
 * @param string $alt Alternative text to use in image tag. Defaults to blank
 * @return string <img> tag for the user's avatar
*/
function get_avatar( $id_or_email, $size = '96', $default = '', $alt = false ) {
	if ( ! get_option('show_avatars') )
		return false;

	if ( false === $alt)
		$safe_alt = '';
	else
		$safe_alt = esc_attr( $alt );

	if ( !is_numeric($size) )
		$size = '96';

	$email = '';
	if ( is_numeric($id_or_email) ) {
		$id = (int) $id_or_email;
		$user = get_userdata($id);
		if ( $user )
			$email = $user->user_email;
	} elseif ( is_object($id_or_email) ) {
		// No avatar for pingbacks or trackbacks

		/**
		 * Filter the list of allowed comment types for retrieving avatars.
		 *
		 * @since 3.0.0
		 *
		 * @param array $types An array of content types. Default only contains 'comment'.
		 */
		$allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
		if ( ! empty( $id_or_email->comment_type ) && ! in_array( $id_or_email->comment_type, (array) $allowed_comment_types ) )
			return false;

		if ( ! empty( $id_or_email->user_id ) ) {
			$id = (int) $id_or_email->user_id;
			$user = get_userdata($id);
			if ( $user )
				$email = $user->user_email;
		}

		if ( ! $email && ! empty( $id_or_email->comment_author_email ) )
			$email = $id_or_email->comment_author_email;
	} else {
		$email = $id_or_email;
	}

	if ( empty($default) ) {
		$avatar_default = get_option('avatar_default');
		if ( empty($avatar_default) )
			$default = 'mystery';
		else
			$default = $avatar_default;
	}

	if ( !empty($email) )
		$email_hash = md5( strtolower( trim( $email ) ) );

	if ( is_ssl() ) {
		$host = 'https://secure.gravatar.com';
	} else {
		if ( !empty($email) )
			$host = sprintf( "http://%d.gravatar.com", ( hexdec( $email_hash[0] ) % 2 ) );
		else
			$host = 'http://0.gravatar.com';
	}

	if ( 'mystery' == $default )
		$default = "$host/avatar/ad516503a11cd5ca435acc9bb6523536?s={$size}"; // ad516503a11cd5ca435acc9bb6523536 == md5('unknown@gravatar.com')
	elseif ( 'blank' == $default )
		$default = $email ? 'blank' : includes_url( 'images/blank.gif' );
	elseif ( !empty($email) && 'gravatar_default' == $default )
		$default = '';
	elseif ( 'gravatar_default' == $default )
		$default = "$host/avatar/?s={$size}";
	elseif ( empty($email) )
		$default = "$host/avatar/?d=$default&amp;s={$size}";
	elseif ( strpos($default, 'http://') === 0 )
		$default = add_query_arg( 's', $size, $default );

	if ( !empty($email) ) {
		$out = "$host/avatar/";
		$out .= $email_hash;
		$out .= '?s='.$size;
		$out .= '&amp;d=' . urlencode( $default );

		$rating = get_option('avatar_rating');
		if ( !empty( $rating ) )
			$out .= "&amp;r={$rating}";

		$out = str_replace( '&#038;', '&amp;', esc_url( $out ) );
		$avatar = "<img alt='{$safe_alt}' src='{$out}' class='avatar avatar-{$size} photo' height='{$size}' width='{$size}' />";
	} else {
		$out = esc_url( $default );
		$avatar = "<img alt='{$safe_alt}' src='{$out}' class='avatar avatar-{$size} photo avatar-default' height='{$size}' width='{$size}' />";
	}

	/**
	 * Filter the avatar to retrieve.
	 *
	 * @since 2.5.0
	 *
	 * @param string            $avatar      Image tag for the user's avatar.
	 * @param int|object|string $id_or_email A user ID, email address, or comment object.
	 * @param int               $size        Square avatar width and height in pixels to retrieve.
	 * @param string            $alt         Alternative text to use in the avatar image tag.
	 *                                       Default empty.
	 */
	return apply_filters( 'get_avatar', $avatar, $id_or_email, $size, $default, $alt );
}
endif;

if ( !function_exists( 'wp_text_diff' ) ) :
/**
 * Displays a human readable HTML representation of the difference between two strings.
 *
 * The Diff is available for getting the changes between versions. The output is
 * HTML, so the primary use is for displaying the changes. If the two strings
 * are equivalent, then an empty string will be returned.
 *
 * The arguments supported and can be changed are listed below.
 *
 * 'title' : Default is an empty string. Titles the diff in a manner compatible
 *		with the output.
 * 'title_left' : Default is an empty string. Change the HTML to the left of the
 *		title.
 * 'title_right' : Default is an empty string. Change the HTML to the right of
 *		the title.
 *
 * @since 2.6.0
 *
 * @see wp_parse_args() Used to change defaults to user defined settings.
 * @uses Text_Diff
 * @uses WP_Text_Diff_Renderer_Table
 *
 * @param string $left_string "old" (left) version of string
 * @param string $right_string "new" (right) version of string
 * @param string|array $args Optional. Change 'title', 'title_left', and 'title_right' defaults.
 * @return string Empty string if strings are equivalent or HTML with differences.
 */
function wp_text_diff( $left_string, $right_string, $args = null ) {
	$defaults = array( 'title' => '', 'title_left' => '', 'title_right' => '' );
	$args = wp_parse_args( $args, $defaults );

	if ( !class_exists( 'WP_Text_Diff_Renderer_Table' ) )
		require( ABSPATH . WPINC . '/wp-diff.php' );

	$left_string  = normalize_whitespace($left_string);
	$right_string = normalize_whitespace($right_string);

	$left_lines  = explode("\n", $left_string);
	$right_lines = explode("\n", $right_string);
	$text_diff = new Text_Diff($left_lines, $right_lines);
	$renderer  = new WP_Text_Diff_Renderer_Table( $args );
	$diff = $renderer->render($text_diff);

	if ( !$diff )
		return '';

	$r  = "<table class='diff'>\n";

	if ( ! empty( $args[ 'show_split_view' ] ) ) {
		$r .= "<col class='content diffsplit left' /><col class='content diffsplit middle' /><col class='content diffsplit right' />";
	} else {
		$r .= "<col class='content' />";
	}

	if ( $args['title'] || $args['title_left'] || $args['title_right'] )
		$r .= "<thead>";
	if ( $args['title'] )
		$r .= "<tr class='diff-title'><th colspan='4'>$args[title]</th></tr>\n";
	if ( $args['title_left'] || $args['title_right'] ) {
		$r .= "<tr class='diff-sub-title'>\n";
		$r .= "\t<td></td><th>$args[title_left]</th>\n";
		$r .= "\t<td></td><th>$args[title_right]</th>\n";
		$r .= "</tr>\n";
	}
	if ( $args['title'] || $args['title_left'] || $args['title_right'] )
		$r .= "</thead>\n";

	$r .= "<tbody>\n$diff\n</tbody>\n";
	$r .= "</table>";

	return $r;
}
endif;