rfc822.php

This is the script which used on 10minutemail.com for temporary email.

<?php
// +-----------------------------------------------------------------------+
// | Copyright (c) 2001-2002, Richard Heyes                                |
// | All rights reserved.                                                  |
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// | modification, are permitted provided that the following conditions    |
// | are met:                                                              |
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// |   notice, this list of conditions and the following disclaimer.       |
// | o Redistributions in binary form must reproduce the above copyright   |
// |   notice, this list of conditions and the following disclaimer in the |
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// |   permission.                                                         |
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// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS   |
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// +-----------------------------------------------------------------------+
// | Authors: Richard Heyes <[e-mail]>                          |
// |          Chuck Hagenbuch <[e-mail]>                            |
// +-----------------------------------------------------------------------+

/**
 * RFC 822 Email address list validation Utility
 *
 * What is it?
 *
 * This class will take an address string, and parse it into it's consituent
 * parts, be that either addresses, groups, or combinations. Nested groups
 * are not supported. The structure it returns is pretty straight forward,
 * and is similar to that provided by the imap_rfc822_parse_adrlist(). Use
 * print_r() to view the structure.
 *
 * How do I use it?
 *
 * $address_string = 'My Group: "Richard" <richard@localhost> (A comment), [e-mail] (Ted Bloggs), Barney;';
 * $structure = Mail_RFC822::parseAddressList($address_string, 'example.com', true)
 * print_r($structure);
 *
 * @author  Richard Heyes <[e-mail]>
 * @author  Chuck Hagenbuch <[e-mail]>
 * @version $Revision: 1.23 $
 * @license BSD
 * @package Mail
 */
class Mail_RFC822 {

    /**
     * The address being parsed by the RFC822 object.
     * @var string $address
     */
    var $address = '';

    /**
     * The default domain to use for unqualified addresses.
     * @var string $default_domain
     */
    var $default_domain = 'localhost';

    /**
     * Should we return a nested array showing groups, or flatten everything?
     * @var boolean $nestGroups
     */
    var $nestGroups = true;

    /**
     * Whether or not to validate atoms for non-ascii characters.
     * @var boolean $validate
     */
    var $validate = true;

    /**
     * The array of raw addresses built up as we parse.
     * @var array $addresses
     */
    var $addresses = array();

    /**
     * The final array of parsed address information that we build up.
     * @var array $structure
     */
    var $structure = array();

    /**
     * The current error message, if any.
     * @var string $error
     */
    var $error = null;

    /**
     * An internal counter/pointer.
     * @var integer $index
     */
    var $index = null;

    /**
     * The number of groups that have been found in the address list.
     * @var integer $num_groups
     * @access public
     */
    var $num_groups = 0;

    /**
     * A variable so that we can tell whether or not we're inside a
     * Mail_RFC822 object.
     * @var boolean $mailRFC822
     */
    var $mailRFC822 = true;

    /**
    * A limit after which processing stops
    * @var int $limit
    */
    var $limit = null;

    /**
     * Sets up the object. The address must either be set here or when
     * calling parseAddressList(). One or the other.
     *
     * @access public
     * @param string  $address         The address(es) to validate.
     * @param string  $default_domain  Default domain/host etc. If not supplied, will be set to localhost.
     * @param boolean $nest_groups     Whether to return the structure with groups nested for easier viewing.
     * @param boolean $validate        Whether to validate atoms. Turn this off if you need to run addresses through before encoding the personal names, for instance.
     *
     * @return object Mail_RFC822 A new Mail_RFC822 object.
     */
    function Mail_RFC822($address = null, $default_domain = null, $nest_groups = null, $validate = null, $limit = null)
    {
        if (isset($address))        $this->address        = $address;
        if (isset($default_domain)) $this->default_domain = $default_domain;
        if (isset($nest_groups))    $this->nestGroups     = $nest_groups;
        if (isset($validate))       $this->validate       = $validate;
        if (isset($limit))          $this->limit          = $limit;
    }

    /**
     * Starts the whole process. The address must either be set here
     * or when creating the object. One or the other.
     *
     * @access public
     * @param string  $address         The address(es) to validate.
     * @param string  $default_domain  Default domain/host etc.
     * @param boolean $nest_groups     Whether to return the structure with groups nested for easier viewing.
     * @param boolean $validate        Whether to validate atoms. Turn this off if you need to run addresses through before encoding the personal names, for instance.
     *
     * @return array A structured array of addresses.
     */
    function parseAddressList($address = null, $default_domain = null, $nest_groups = null, $validate = null, $limit = null)
    {
        if (!isset($this) || !isset($this->mailRFC822)) {
            $obj = new Mail_RFC822($address, $default_domain, $nest_groups, $validate, $limit);
            return $obj->parseAddressList();
        }

        if (isset($address))        $this->address        = $address;
        if (isset($default_domain)) $this->default_domain = $default_domain;
        if (isset($nest_groups))    $this->nestGroups     = $nest_groups;
        if (isset($validate))       $this->validate       = $validate;
        if (isset($limit))          $this->limit          = $limit;

        $this->structure  = array();
        $this->addresses  = array();
        $this->error      = null;
        $this->index      = null;

        // Unfold any long lines in $this->address.
        $this->address = preg_replace('/\r?\n/', "\r\n", $this->address);
        $this->address = preg_replace('/\r\n(\t| )+/', ' ', $this->address);

        while ($this->address = $this->_splitAddresses($this->address));

        if ($this->address === false || isset($this->error)) {
            require_once 'PEAR.php';
            return PEAR::raiseError($this->error);
        }

        // Validate each address individually.  If we encounter an invalid
        // address, stop iterating and return an error immediately.
        foreach ($this->addresses as $address) {
            $valid = $this->_validateAddress($address);

            if ($valid === false || isset($this->error)) {
                require_once 'PEAR.php';
                return PEAR::raiseError($this->error);
            }

            if (!$this->nestGroups) {
                $this->structure = array_merge($this->structure, $valid);
            } else {
                $this->structure[] = $valid;
            }
        }

        return $this->structure;
    }

    /**
     * Splits an address into separate addresses.
     *
     * @access private
     * @param string $address The addresses to split.
     * @return boolean Success or failure.
     */
    function _splitAddresses($address)
    {
        if (!empty($this->limit) && count($this->addresses) == $this->limit) {
            return '';
        }

        if ($this->_isGroup($address) && !isset($this->error)) {
            $split_char = ';';
            $is_group   = true;
        } elseif (!isset($this->error)) {
            $split_char = ',';
            $is_group   = false;
        } elseif (isset($this->error)) {
            return false;
        }

        // Split the string based on the above ten or so lines.
        $parts  = explode($split_char, $address);
        $string = $this->_splitCheck($parts, $split_char);

        // If a group...
        if ($is_group) {
            // If $string does not contain a colon outside of
            // brackets/quotes etc then something's fubar.

            // First check there's a colon at all:
            if (strpos($string, ':') === false) {
                $this->error = 'Invalid address: ' . $string;
                return false;
            }

            // Now check it's outside of brackets/quotes:
            if (!$this->_splitCheck(explode(':', $string), ':')) {
                return false;
            }

            // We must have a group at this point, so increase the counter:
            $this->num_groups++;
        }

        // $string now contains the first full address/group.
        // Add to the addresses array.
        $this->addresses[] = array(
                                   'address' => trim($string),
                                   'group'   => $is_group
                                   );

        // Remove the now stored address from the initial line, the +1
        // is to account for the explode character.
        $address = trim(substr($address, strlen($string) + 1));

        // If the next char is a comma and this was a group, then
        // there are more addresses, otherwise, if there are any more
        // chars, then there is another address.
        if ($is_group && substr($address, 0, 1) == ','){
            $address = trim(substr($address, 1));
            return $address;

        } elseif (strlen($address) > 0) {
            return $address;

        } else {
            return '';
        }

        // If you got here then something's off
        return false;
    }

    /**
     * Checks for a group at the start of the string.
     *
     * @access private
     * @param string $address The address to check.
     * @return boolean Whether or not there is a group at the start of the string.
     */
    function _isGroup($address)
    {
        // First comma not in quotes, angles or escaped:
        $parts  = explode(',', $address);
        $string = $this->_splitCheck($parts, ',');

        // Now we have the first address, we can reliably check for a
        // group by searching for a colon that's not escaped or in
        // quotes or angle brackets.
        if (count($parts = explode(':', $string)) > 1) {
            $string2 = $this->_splitCheck($parts, ':');
            return ($string2 !== $string);
        } else {
            return false;
        }