This standalone script migrates Users from Drupal 6 to Drupal 7

migrateuserd6d7.php

<?php
    /*
    Standalone PHP script to migrate users from Drupal 6 to Drupal 7 programatically.
    Date: 9-4-2012
    */

    // set HTTP_HOST or drupal will refuse to bootstrap
    $_SERVER['HTTP_HOST'] = 'example.org';
    $_SERVER['REMOTE_ADDR'] = '127.0.0.1';


    //root of Drupal 7 site
    $DRUPAL7_ROOT="/var/www/ace";
    define('DRUPAL_ROOT',$DRUPAL7_ROOT);
    chdir($DRUPAL7_ROOT);
    require_once "./includes/bootstrap.inc";
    drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
    require_once "./includes/password.inc";

    //connect to Drupal 6 database
    //syntax:mysqli(hostname,username,password,databasename);
    $db= new mysqli('localhost','ace6','ace6','ace6');
    if(mysqli_connect_errno())  {
        echo "Conection error. Could not connect to Drupal 6 site!";
        exit;
    }

    //get users from Drupal 6 database
    $query="select * from users";
    $result=$db->query($query);
    //count number of users
    $num_results=$result->num_rows;
    for($i=0;$i<$num_results;$i++){

        //fetch each row/user
        $row=$result->fetch_assoc();

        //migrate only active users
        if($row['status']==1){

            //convert password from Drupal 6 style to Drupal 7 style
            $hashed_pass='U'.user_hash_password($row['pass'],11);

            //check if user with same email address already exists in Drupal 7 database, if it does, do not migrate
            if (!user_load_by_mail($row['mail'])) {
                $account = new stdClass;
                $account->is_new = TRUE;
                $account->name = $row['name'];
                $account->pass = $hashed_pass;
                $account->mail = $row['mail'];
                $account->init = $row['mail'];
                $account->status = TRUE;
                $account->roles = array(DRUPAL_AUTHENTICATED_RID => TRUE);
                $account->timezone = variable_get('date_default_timezone', '');
                //create user in Drupal 7 site
                user_save($account);
                //print message
                echo "User acount ".$row['name']." has been created\n";
            }
        }

    }
    ?>