cron.php

<?php

/// This script looks through all the module directories for cron.php files
/// and runs them.  These files can contain cleanup functions, email functions
/// or anything that needs to be run on a regular basis.
///
/// This file is best run from cron on the host system (ie outside PHP).
/// The script can either be invoked via the web server or via a standalone
/// version of PHP compiled for CGI.
///
/// eg   wget -q -O /dev/null 'http://moodle.somewhere.edu/admin/cron.php'
/// or   php /web/moodle/admin/cron.php
    set_time_limit(0);
    $starttime = microtime();

/// this cron script might be considered to be a CLI script even when accessed over HTTP,
/// we do not want HTML in output and there is no real session ;-)
/// NOTE: do not use this hack in your cli scripts, it is defined automatically
///       in lib/setup.php, all you need to do is to prevent access via web
    define('CLI_SCRIPT', true);

/// Following hack used to identify cron and other CLI scripts - use CLI_SCRIPT or $FULLME == "/$CFG->admin/cropn.php" instead
    //define('FULLME', 'cron');

/// Do not set moodle cookie because we do not need it here, it is better to emulate session
    define('NO_MOODLE_COOKIES', true);

    require_once(dirname(__FILE__) . '/../config.php');
    require_once($CFG->libdir.'/adminlib.php');
    require_once($CFG->libdir.'/gradelib.php');

/// Extra debugging (set in config.php)
    if (!empty($CFG->showcronsql)) {
        $DB->set_debug(true);
    }
    if (!empty($CFG->showcrondebugging)) {
        $CFG->debug = DEBUG_DEVELOPER;
        $CFG->debugdisplay = true;
    }

/// extra safety
    session_get_instance()->write_close();

/// check if execution allowed
    if (isset($_SERVER['REMOTE_ADDR'])) { // if the script is accessed via the web.
        if (!empty($CFG->cronclionly)) {
            // This script can only be run via the cli.
            print_error('cronerrorclionly', 'admin');
            exit;
        }
        // This script is being called via the web, so check the password if there is one.
        if (!empty($CFG->cronremotepassword)) {
            $pass = optional_param('password', '', PARAM_RAW);
            if($pass != $CFG->cronremotepassword) {
                // wrong password.
                print_error('cronerrorpassword', 'admin');
                exit;
            }
        }
    }


/// emulate normal session
    cron_setup_user();

/// send mime type and encoding
    if (check_browser_version('MSIE')) {
        //ugly IE hack to work around downloading instead of viewing
        @header('Content-Type: text/html; charset=utf-8');
        echo "<xmp>"; //<pre> is not good enough for us here
    } else {
        //send proper plaintext header
        @header('Content-Type: text/plain; charset=utf-8');
    }

/// no more headers and buffers
    while(@ob_end_flush());

/// increase memory limit (PHP 5.2 does different calculation, we need more memory now)
    @raise_memory_limit('128M');

/// Start output log

    $timenow  = time();

    mtrace("Server Time: ".date('r',$timenow)."\n\n");


/// Session gc

    mtrace("Cleaning up stale sessions");
    session_gc();

/// Run all cron jobs for each module

    mtrace("Starting activity modules");
    get_mailer('buffer');
    if ($mods = $DB->get_records_select("modules", "cron > 0 AND ((? - lastcron) > cron) AND visible = 1", array($timenow))) {
        foreach ($mods as $mod) {
            $libfile = "$CFG->dirroot/mod/$mod->name/lib.php";
            if (file_exists($libfile)) {
                include_once($libfile);
                $cron_function = $mod->name."_cron";
                if (function_exists($cron_function)) {
                    mtrace("Processing module function $cron_function ...", '');
                    $pre_dbqueries = null;
                    $pre_dbqueries = $DB->perf_get_queries();
                    $pre_time      = microtime(1);
                    if ($cron_function()) {
                        if (!$DB->set_field("modules", "lastcron", $timenow, array("id"=>$mod->id))) {
                            mtrace("Error: could not update timestamp for $mod->fullname");
                        }
                    }
                    if (isset($pre_dbqueries)) {
                        mtrace("... used " . ($DB->perf_get_queries() - $pre_dbqueries) . " dbqueries");
                        mtrace("... used " . (microtime(1) - $pre_time) . " seconds");
                    }
                /// Reset possible changes by modules to time_limit. MDL-11597
                    @set_time_limit(0);
                    mtrace("done.");
                }
            }
        }
    }
    get_mailer('close');
    mtrace("Finished activity modules");

    mtrace("Starting blocks");
    if ($blocks = $DB->get_records_select("block", "cron > 0 AND ((? - lastcron) > cron) AND visible = 1", array($timenow))) {
        // we will need the base class.
        require_once($CFG->dirroot.'/blocks/moodleblock.class.php');
        foreach ($blocks as $block) {
            $blockfile = $CFG->dirroot.'/blocks/'.$block->name.'/block_'.$block->name.'.php';
            if (file_exists($blockfile)) {
                require_once($blockfile);
                $classname = 'block_'.$block->name;
                $blockobj = new $classname;
                if (method_exists($blockobj,'cron')) {
                    mtrace("Processing cron function for ".$block->name.'....','');
                    if ($blockobj->cron()) {
                        if (!$DB->set_field('block', 'lastcron', $timenow, array('id'=>$block->id))) {
                            mtrace('Error: could not update timestamp for '.$block->name);
                        }
                    }
                /// Reset possible changes by blocks to time_limit. MDL-11597
                    @set_time_limit(0);
                    mtrace('done.');
                }
            }

        }
    }
    mtrace('Finished blocks');

    mtrace("Starting quiz reports");
    if ($reports = $DB->get_records_select('quiz_report', "cron > 0 AND ((? - lastcron) > cron)", array($timenow))) {
        foreach ($reports as $report) {
            $cronfile = "$CFG->dirroot/mod/quiz/report/$report->name/cron.php";
            if (file_exists($cronfile)) {
                include_once($cronfile);
                $cron_function = 'quiz_report_'.$report->name."_cron";
                if (function_exists($cron_function)) {
                    mtrace("Processing quiz report cron function $cron_function ...", '');
                    $pre_dbqueries = null;
                    $pre_dbqueries = $DB->perf_get_queries();
                    $pre_time      = microtime(1);
                    if ($cron_function()) {
                        if (!$DB->set_field('quiz_report', "lastcron", $timenow, array("id"=>$report->id))) {
                            mtrace("Error: could not update timestamp for $report->name");
                        }
                    }
                    if (isset($pre_dbqueries)) {
                        mtrace("... used " . ($DB->perf_get_queries() - $pre_dbqueries) . " dbqueries");
                        mtrace("... used " . (microtime(1) - $pre_time) . " seconds");
                    }
                    mtrace("done.");
                }
            }
        }
    }
    mtrace("Finished quiz reports");

    mtrace('Starting admin reports');
    // Admin reports do not have a database table that lists them. Instead a
    // report includes cron.php with function report_reportname_cron() if it wishes
    // to be cronned. It is up to cron.php to handle e.g. if it only needs to
    // actually do anything occasionally.
    $reports = get_plugin_list('report');
    foreach($reports as $report => $reportdir) {
        $cronfile = $reportdir.'/cron.php';
        if (file_exists($cronfile)) {
            require_once($cronfile);
            $cronfunction = 'report_'.$report.'_cron';
            mtrace('Processing cron function for '.$report.'...', '');
            $pre_dbqueries = null;
            $pre_dbqueries = $DB->perf_get_queries();
            $pre_time      = microtime(true);
            $cronfunction();
            if (isset($pre_dbqueries)) {
                mtrace("... used " . ($DB->perf_get_queries() - $pre_dbqueries) . " dbqueries");
                mtrace("... used " . round(microtime(true) - $pre_time, 2) . " seconds");
            }
            mtrace('done.');
        }
    }
    mtrace('Finished admin reports');

    mtrace('Removing expired enrolments ...', '');     // See MDL-8785
    $timenow = time();
    $somefound = false;
    // The preferred way saves memory, datablib
    // find courses where limited enrolment is enabled
    $sql = "SELECT ra.roleid, ra.userid, ra.contextid
              FROM {course} c
              JOIN {context} cx ON cx.instanceid = c.id
              JOIN {role_assignments} ra ON ra.contextid = cx.id
             WHERE cx.contextlevel = '".CONTEXT_COURSE."'
                   AND ra.timeend > 0
                   AND ra.timeend < ?
                   AND c.enrolperiod > 0";
    if ($rs = $DB->get_recordset_sql($sql, array($timenow))) {
        foreach ($rs as $oldenrolment) {
            role_unassign($oldenrolment->roleid, $oldenrolment->userid, 0, $oldenrolment->contextid);
            $somefound = true;
        }
        $rs->close();
    }
    if ($somefound) {
        mtrace('Done');
    } else {
        mtrace('none found');
    }



    mtrace('Starting main gradebook job ...');
    grade_cron();
    mtrace('done.');


    mtrace('Starting processing the event queue...');
    events_cron();
    mtrace('done.');


    if ($CFG->enablecompletion) {
        // Completion cron
        mtrace('Starting the completion cron...');
        require_once($CFG->libdir . '/completion/cron.php');
        completion_cron();
        mtrace('done');
    }


    if ($CFG->enableportfolios) {
        // Portfolio cron
        mtrace('Starting the portfolio cron...');
        require_once($CFG->libdir . '/portfoliolib.php');
        portfolio_cron();
        mtrace('done');
    }

/// Run all core cron jobs, but not every time since they aren't too important.
/// These don't have a timer to reduce load, so we'll use a random number
/// to randomly choose the percentage of times we should run these jobs.

    srand ((double) microtime() * 10000000);
    $random100 = rand(0,100);

    if ($random100 < 20) {     // Approximately 20% of the time.
        mtrace("Running clean-up tasks...");

        /// Unenrol users who haven't logged in for $CFG->longtimenosee

        if ($CFG->longtimenosee) { // value in days
            $cuttime = $timenow - ($CFG->longtimenosee * 3600 * 24);
            $rs = $DB->get_recordset_sql ("SELECT id, userid, courseid
                                             FROM {user_lastaccess}
                                            WHERE courseid != ".SITEID."
                                                  AND timeaccess < ?", array($cuttime));
            foreach ($rs as $assign) {
                if ($context = get_context_instance(CONTEXT_COURSE, $assign->courseid)) {
                    if (role_unassign(0, $assign->userid, 0, $context->id)) {
                        mtrace("removing user $assign->userid from course $assign->courseid as they have not accessed the course for over $CFG->longtimenosee days");
                    }
                }
            }
            $rs->close();
        /// Execute the same query again, looking for remaining records and deleting them
        /// if the user hasn't moodle/course:participate in the CONTEXT_COURSE context (orphan records)
            $rs = $DB->get_recordset_sql ("SELECT id, userid, courseid
                                             FROM {user_lastaccess}
                                            WHERE courseid != ".SITEID."
                                                  AND timeaccess < ?", array($cuttime));
            foreach ($rs as $assign) {
                if ($context = get_context_instance(CONTEXT_COURSE, $assign->courseid)) {
                    if (!is_enrolled($context, $assign->userid) and !is_viewing($context, $assign->userid)) {
                        $DB->delete_records('user_lastaccess', array('userid'=>$assign->userid, 'courseid'=>$assign->courseid));
                        mtrace("Deleted orphan user_lastaccess for user $assign->userid from course $assign->courseid");
                    }
                }
            }
            $rs->close();
        }
        flush();


        /// Delete users who haven't confirmed within required period

        if (!empty($CFG->deleteunconfirmed)) {
            $cuttime = $timenow - ($CFG->deleteunconfirmed * 3600);
            $rs = $DB->get_recordset_sql ("SELECT id, firstname, lastname
                                             FROM {user}
                                            WHERE confirmed = 0 AND firstaccess > 0
                                                  AND firstaccess < ?", array($cuttime));
            foreach ($rs as $user) {
                if ($DB->delete_records('user', array('id'=>$user->id))) {
                    mtrace("Deleted unconfirmed user for ".fullname($user, true)." ($user->id)");
                }
            }
            $rs->close();
        }
        flush();


        /// Delete users who haven't completed profile within required period

        if (!empty($CFG->deleteincompleteusers)) {
            $cuttime = $timenow - ($CFG->deleteincompleteusers * 3600);
            $rs = $DB->get_recordset_sql ("SELECT id, username
                                             FROM {user}
                                            WHERE confirmed = 1 AND lastaccess > 0
                                                  AND lastaccess < ? AND deleted = 0
                                                  AND (lastname = '' OR firstname = '' OR email = '')",
                                          array($cuttime));
            foreach ($rs as $user) {
                if (delete_user($user)) {
                    mtrace("Deleted not fully setup user $user->username ($user->id)");
                }
            }
            $rs->close();
        }
        flush();


        /// Delete old logs to save space (this might need a timer to slow it down...)

        if (!empty($CFG->loglifetime)) {  // value in days
            $loglifetime = $timenow - ($CFG->loglifetime * 3600 * 24);
            if ($DB->delete_records_select("log", "time < ?", array($loglifetime))) {
                mtrace("Deleted old log records");
            }
        }
        flush();


        /// Delete old cached texts

        if (!empty($CFG->cachetext)) {   // Defined in config.php
            $cachelifetime = time() - $CFG->cachetext - 60;  // Add an extra minute to allow for really heavy sites
            if ($DB->delete_records_select('cache_text', "timemodified < ?", array($cachelifetime))) {
                mtrace("Deleted old cache_text records");
            }
        }
        flush();

        if (!empty($CFG->notifyloginfailures)) {
            notify_login_failures();
            mtrace('Notified login failured');
        }
        flush();

        sync_metacourses();
        mtrace('Synchronised metacourses');

        //
        // generate new password emails for users
        //
        mtrace('checking for create_password');
        if ($DB->count_records('user_preferences', array('name'=>'create_password', 'value'=>'1'))) {
            mtrace('creating passwords for new users');
            $newusers = $DB->get_records_sql("SELECT u.id as id, u.email, u.firstname,
                                                     u.lastname, u.username,
                                                     p.id as prefid
                                                FROM {user} u
                                                JOIN {user_preferences} p ON u.id=p.userid
                                               WHERE p.name='create_password' AND p.value='1' AND u.email !='' ");

            foreach ($newusers as $newuserid => $newuser) {
                $newuser->emailstop = 0; // send email regardless
                // email user
                if (setnew_password_and_mail($newuser)) {
                    // remove user pref
                    $DB->delete_records('user_preferences', array('id'=>$newuser->prefid));
                } else {
                    trigger_error("Could not create and mail new user password!");
                }
            }
        }

        if (!empty($CFG->usetags)) {
            require_once($CFG->dirroot.'/tag/lib.php');
            tag_cron();
            mtrace ('Executed tag cron');
        }

        // Accesslib stuff
        cleanup_contexts();
        mtrace ('Cleaned up contexts');
        gc_cache_flags();
        mtrace ('Cleaned cache flags');
        // If you suspect that the context paths are somehow corrupt
        // replace the line below with: build_context_path(true);
        build_context_path();
        mtrace ('Built context paths');

        mtrace("Finished clean-up tasks...");

    } // End of occasional clean-up tasks

    // Disabled until implemented. MDL-21432, MDL-22184
    if (1 == 2 && empty($CFG->disablescheduledbackups)) {   // Defined in config.php
        //Execute backup's cron
        //Perhaps a long time and memory could help in large sites
        @set_time_limit(0);
        @raise_memory_limit("192M");
        if (function_exists('apache_child_terminate')) {
            // if we are running from Apache, give httpd a hint that
            // it can recycle the process after it's done. Apache's
            // memory management is truly awful but we can help it.
            @apache_child_terminate();
        }
        if (file_exists("$CFG->dirroot/backup/backup_scheduled.php") and
            file_exists("$CFG->dirroot/backup/backuplib.php") and
            file_exists("$CFG->dirroot/backup/lib.php") and
            file_exists("$CFG->libdir/blocklib.php")) {
            include_once("$CFG->dirroot/backup/backup_scheduled.php");
            include_once("$CFG->dirroot/backup/backuplib.php");
            include_once("$CFG->dirroot/backup/lib.php");
            mtrace("Running backups if required...");

            if (! schedule_backup_cron()) {
                mtrace("ERROR: Something went wrong while performing backup tasks!!!");
            } else {
                mtrace("Backup tasks finished.");
            }
        }
    }

/// Run the auth cron, if any
/// before enrolments because it might add users that will be needed in enrol plugins
    $auths = get_enabled_auth_plugins();

    mtrace("Running auth crons if required...");
    foreach ($auths as $auth) {
        $authplugin = get_auth_plugin($auth);
        if (method_exists($authplugin, 'cron')) {
            mtrace("Running cron for auth/$auth...");
            $authplugin->cron();
            if (!empty($authplugin->log)) {
                mtrace($authplugin->log);
            }
        }
        unset($authplugin);
    }

/// Run the enrolment cron, if any
    if (!($plugins = explode(',', $CFG->enrol_plugins_enabled))) {
        $plugins = array($CFG->enrol);
    }
    require_once($CFG->dirroot .'/enrol/enrol.class.php');
    foreach ($plugins as $p) {
        $enrol = enrolment_factory::factory($p);
        if (method_exists($enrol, 'cron')) {
            $enrol->cron();
        }
        if (!empty($enrol->log)) {
            mtrace($enrol->log);
        }
        unset($enrol);
    }

    if (!empty($CFG->enablestats) and empty($CFG->disablestatsprocessing)) {
        require_once($CFG->dirroot.'/lib/statslib.php');
        // check we're not before our runtime
        $timetocheck = stats_get_base_daily() + $CFG->statsruntimestarthour*60*60 + $CFG->statsruntimestartminute*60;

        if (time() > $timetocheck) {
            // process configured number of days as max (defaulting to 31)
            $maxdays = empty($CFG->statsruntimedays) ? 31 : abs($CFG->statsruntimedays);
            if (stats_cron_daily($maxdays)) {
                if (stats_cron_weekly()) {
                    if (stats_cron_monthly()) {
                        stats_clean_old();
                    }
                }
            }
            @set_time_limit(0);
        } else {
            mtrace('Next stats run after:'. userdate($timetocheck));
        }
    }

    // run gradebook import/export/report cron
    if ($gradeimports = get_plugin_list('gradeimport')) {
        foreach ($gradeimports as $gradeimport => $plugindir) {
            if (file_exists($plugindir.'/lib.php')) {
                require_once($plugindir.'/lib.php');
                $cron_function = 'grade_import_'.$gradeimport.'_cron';
                if (function_exists($cron_function)) {
                    mtrace("Processing gradebook import function $cron_function ...", '');
                    $cron_function();
                }
            }
        }
    }

    if ($gradeexports = get_plugin_list('gradeexport')) {
        foreach ($gradeexports as $gradeexport => $plugindir) {
            if (file_exists($plugindir.'/lib.php')) {
                require_once($plugindir.'/lib.php');
                $cron_function = 'grade_export_'.$gradeexport.'_cron';
                if (function_exists($cron_function)) {
                    mtrace("Processing gradebook export function $cron_function ...", '');
                    $cron_function();
                }
            }
        }
    }

    if ($gradereports = get_plugin_list('gradereport')) {
        foreach ($gradereports as $gradereport => $plugindir) {
            if (file_exists($plugindir.'/lib.php')) {
                require_once($plugindir.'/lib.php');
                $cron_function = 'grade_report_'.$gradereport.'_cron';
                if (function_exists($cron_function)) {
                    mtrace("Processing gradebook report function $cron_function ...", '');
                    $cron_function();
                }
            }
        }
    }

    // Run external blog cron if needed
    if ($CFG->useexternalblogs) {
        require_once($CFG->dirroot . '/blog/lib.php');
        mtrace("Fetching external blog entries...", '');
        $sql = "timefetched < ? OR timefetched = 0";
        $externalblogs = $DB->get_records_select('blog_external', $sql, array(mktime() - $CFG->externalblogcrontime));

        foreach ($externalblogs as $eb) {
            blog_sync_external_entries($eb);
        }
    }

    // Run blog associations cleanup
    if ($CFG->useblogassociations) {
        require_once($CFG->dirroot . '/blog/lib.php');
        // delete entries whose contextids no longer exists
        mtrace("Deleting blog associations linked to non-existent contexts...", '');
        $DB->delete_records_select('blog_association', 'contextid NOT IN (SELECT id FROM {context})');
    }

    // cleanup file trash
    $fs = get_file_storage();
    $fs->cron();

    //cleanup old session linked tokens
    //deletes the session linked tokens that are over a day old.
    mtrace("Deleting session linked tokens more than one day old...", '');
    $DB->delete_records_select('external_tokens', 'lastaccess < :onedayago AND tokentype = :tokentype', 
                    array('onedayago' => time() - DAYSECS, 'tokentype' => EXTERNAL_TOKEN_EMBEDDED));
    mtrace('done.');
    
    // run any customized cronjobs, if any
    if ($locals = get_plugin_list('local')) {
        mtrace('Processing customized cron scripts ...', '');
        foreach ($locals as $local => $localdir) {
            if (file_exists("$localdir/cron.php")) {
                include("$localdir/cron.php");
            }
        }
        mtrace('done.');
    }


    mtrace("Cron script completed correctly");

    $difftime = microtime_diff($starttime, microtime());
    mtrace("Execution took ".$difftime." seconds");

/// finish the IE hack
    if (check_browser_version('MSIE')) {
        echo "</xmp>";
    }