lib/moodlelib.php

   1 <?php // $Id$
   2
   3 ///////////////////////////////////////////////////////////////////////////
   4 //                                                                       //
   5 // NOTICE OF COPYRIGHT                                                   //
   6 //                                                                       //
   7 // Moodle - Modular Object-Oriented Dynamic Learning Environment         //
   8 //          http://moodle.org                                            //
   9 //                                                                       //
  10 // Copyright (C) 1999-2004  Martin Dougiamas  http://dougiamas.com       //
  11 //                                                                       //
  12 // This program is free software; you can redistribute it and/or modify  //
  13 // it under the terms of the GNU General Public License as published by  //
  14 // the Free Software Foundation; either version 2 of the License, or     //
  15 // (at your option) any later version.                                   //
  16 //                                                                       //
  17 // This program is distributed in the hope that it will be useful,       //
  18 // but WITHOUT ANY WARRANTY; without even the implied warranty of        //
  19 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         //
  20 // GNU General Public License for more details:                          //
  21 //                                                                       //
  22 //          http://www.gnu.org/copyleft/gpl.html                         //
  23 //                                                                       //
  24 ///////////////////////////////////////////////////////////////////////////
  25
  26 /**
  27  * moodlelib.php - Moodle main library
  28  *
  29  * Main library file of miscellaneous general-purpose Moodle functions.
  30  * Other main libraries:
  31  *  - weblib.php      - functions that produce web output
  32  *  - datalib.php     - functions that access the database
  33  * @author Martin Dougiamas
  34  * @version $Id$
  35  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  36  * @package moodlecore
  37  */
  38
  39 /// CONSTANTS (Encased in phpdoc proper comments)/////////////////////////
  40
  41 /**
  42  * Used by some scripts to check they are being called by Moodle
  43  */
  44 define('MOODLE_INTERNAL', true);
  45
  46 /// Date and time constants ///
  47 /**
  48  * Time constant - the number of seconds in a year
  49  */
  50
  51 define('YEARSECS', 31536000);
  52
  53 /**
  54  * Time constant - the number of seconds in a week
  55  */
  56 define('WEEKSECS', 604800);
  57
  58 /**
  59  * Time constant - the number of seconds in a day
  60  */
  61 define('DAYSECS', 86400);
  62
  63 /**
  64  * Time constant - the number of seconds in an hour
  65  */
  66 define('HOURSECS', 3600);
  67
  68 /**
  69  * Time constant - the number of seconds in a minute
  70  */
  71 define('MINSECS', 60);
  72
  73 /**
  74  * Time constant - the number of minutes in a day
  75  */
  76 define('DAYMINS', 1440);
  77
  78 /**
  79  * Time constant - the number of minutes in an hour
  80  */
  81 define('HOURMINS', 60);
  82
  83 /// Parameter constants - every call to optional_param(), required_param()  ///
  84 /// or clean_param() should have a specified type of parameter.  //////////////
  85
  86 /**
  87  * PARAM_RAW specifies a parameter that is not cleaned/processed in any way;
  88  * originally was 0, but changed because we need to detect unknown
  89  * parameter types and swiched order in clean_param().
  90  */
  91 define('PARAM_RAW', 666);
  92
  93 /**
  94  * PARAM_CLEAN - obsoleted, please try to use more specific type of parameter.
  95  * It was one of the first types, that is why it is abused so much ;-)
  96  */
  97 define('PARAM_CLEAN',    0x0001);
  98
  99 /**
 100  * PARAM_INT - integers only, use when expecting only numbers.
 101  */
 102 define('PARAM_INT',      0x0002);
 103
 104 /**
 105  * PARAM_INTEGER - an alias for PARAM_INT
 106  */
 107 define('PARAM_INTEGER',  0x0002);
 108
 109 /**
 110  * PARAM_NUMBER - a real/floating point number.
 111  */
 112 define('PARAM_NUMBER',  0x000a);
 113
 114 /**
 115  * PARAM_ALPHA - contains only english letters.
 116  */
 117 define('PARAM_ALPHA',    0x0004);
 118
 119 /**
 120  * PARAM_ACTION - an alias for PARAM_ALPHA, use for various actions in formas and urls
 121  * @TODO: should we alias it to PARAM_ALPHANUM ?
 122  */
 123 define('PARAM_ACTION',   0x0004);
 124
 125 /**
 126  * PARAM_FORMAT - an alias for PARAM_ALPHA, use for names of plugins, formats, etc.
 127  * @TODO: should we alias it to PARAM_ALPHANUM ?
 128  */
 129 define('PARAM_FORMAT',   0x0004);
 130
 131 /**
 132  * PARAM_NOTAGS - all html tags are stripped from the text. Do not abuse this type.
 133  */
 134 define('PARAM_NOTAGS',   0x0008);
 135
 136  /**
 137  * PARAM_MULTILANG - alias of PARAM_TEXT.
 138  */
 139 define('PARAM_MULTILANG',  0x0009);
 140
 141  /**
 142  * PARAM_TEXT - general plain text compatible with multilang filter, no other html tags.
 143  */
 144 define('PARAM_TEXT',  0x0009);
 145
 146 /**
 147  * PARAM_FILE - safe file name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 148  */
 149 define('PARAM_FILE',     0x0010);
 150
 151 /**
 152  * PARAM_PATH - safe relative path name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 153  * note: the leading slash is not removed, window drive letter is not allowed
 154  */
 155 define('PARAM_PATH',     0x0020);
 156
 157 /**
 158  * PARAM_HOST - expected fully qualified domain name (FQDN) or an IPv4 dotted quad (IP address)
 159  */
 160 define('PARAM_HOST',     0x0040);
 161
 162 /**
 163  * PARAM_URL - expected properly formatted URL.
 164  */
 165 define('PARAM_URL',      0x0080);
 166
 167 /**
 168  * PARAM_LOCALURL - expected properly formatted URL as well as one that refers to the local server itself. (NOT orthogonal to the others! Implies PARAM_URL!)
 169  */
 170 define('PARAM_LOCALURL', 0x0180);
 171
 172 /**
 173  * PARAM_CLEANFILE - safe file name, all dangerous and regional chars are removed,
 174  * use when you want to store a new file submitted by students
 175  */
 176 define('PARAM_CLEANFILE',0x0200);
 177
 178 /**
 179  * PARAM_ALPHANUM - expected numbers and letters only.
 180  */
 181 define('PARAM_ALPHANUM', 0x0400);
 182
 183 /**
 184  * PARAM_BOOL - converts input into 0 or 1, use for switches in forms and urls.
 185  */
 186 define('PARAM_BOOL',     0x0800);
 187
 188 /**
 189  * PARAM_CLEANHTML - cleans submitted HTML code and removes slashes
 190  * note: do not forget to addslashes() before storing into database!
 191  */
 192 define('PARAM_CLEANHTML',0x1000);
 193
 194 /**
 195  * PARAM_ALPHAEXT the same contents as PARAM_ALPHA plus the chars in quotes: "/-_" allowed,
 196  * suitable for include() and require()
 197  * @TODO: should we rename this function to PARAM_SAFEDIRS??
 198  */
 199 define('PARAM_ALPHAEXT', 0x2000);
 200
 201 /**
 202  * PARAM_SAFEDIR - safe directory name, suitable for include() and require()
 203  */
 204 define('PARAM_SAFEDIR',  0x4000);
 205
 206 /**
 207  * PARAM_SEQUENCE - expects a sequence of numbers like 8 to 1,5,6,4,6,8,9.  Numbers and comma only.
 208  */
 209 define('PARAM_SEQUENCE',  0x8000);
 210
 211 /**
 212  * PARAM_PEM - Privacy Enhanced Mail format
 213  */
 214 define('PARAM_PEM',      0x10000);
 215
 216 /**
 217  * PARAM_BASE64 - Base 64 encoded format
 218  */
 219 define('PARAM_BASE64',   0x20000);
 220
 221
 222 /// Page types ///
 223 /**
 224  * PAGE_COURSE_VIEW is a definition of a page type. For more information on the page class see moodle/lib/pagelib.php.
 225  */
 226 define('PAGE_COURSE_VIEW', 'course-view');
 227
 228 /// Debug levels ///
 229 /** no warnings at all */
 230 define ('DEBUG_NONE', 0);
 231 /** E_ERROR | E_PARSE */
 232 define ('DEBUG_MINIMAL', 5);
 233 /** E_ERROR | E_PARSE | E_WARNING | E_NOTICE */
 234 define ('DEBUG_NORMAL', 15);
 235 /** E_ALL without E_STRICT and E_RECOVERABLE_ERROR for now */
 236 define ('DEBUG_ALL', 2047);
 237 /** DEBUG_ALL with extra Moodle debug messages - (DEBUG_ALL | 32768) */
 238 define ('DEBUG_DEVELOPER', 34815);
 239
 240 /**
 241  * Blog access level constant declaration
 242  */
 243 define ('BLOG_USER_LEVEL', 1);
 244 define ('BLOG_GROUP_LEVEL', 2);
 245 define ('BLOG_COURSE_LEVEL', 3);
 246 define ('BLOG_SITE_LEVEL', 4);
 247 define ('BLOG_GLOBAL_LEVEL', 5);
 248
 249
 250
 251 /// PARAMETER HANDLING ////////////////////////////////////////////////////
 252
 253 /**
 254  * Returns a particular value for the named variable, taken from
 255  * POST or GET.  If the parameter doesn't exist then an error is
 256  * thrown because we require this variable.
 257  *
 258  * This function should be used to initialise all required values
 259  * in a script that are based on parameters.  Usually it will be
 260  * used like this:
 261  *    $id = required_param('id');
 262  *
 263  * @param string $parname the name of the page parameter we want
 264  * @param int $type expected type of parameter
 265  * @return mixed
 266  */
 267 function required_param($parname, $type=PARAM_CLEAN) {
 268
 269     // detect_unchecked_vars addition
 270     global $CFG;
 271     if (!empty($CFG->detect_unchecked_vars)) {
 272         global $UNCHECKED_VARS;
 273         unset ($UNCHECKED_VARS->vars[$parname]);
 274     }
 275
 276     if (isset($_POST[$parname])) {       // POST has precedence
 277         $param = $_POST[$parname];
 278     } else if (isset($_GET[$parname])) {
 279         $param = $_GET[$parname];
 280     } else {
 281         error('A required parameter ('.$parname.') was missing');
 282     }
 283
 284     return clean_param($param, $type);
 285 }
 286
 287 /**
 288  * Returns a particular value for the named variable, taken from
 289  * POST or GET, otherwise returning a given default.
 290  *
 291  * This function should be used to initialise all optional values
 292  * in a script that are based on parameters.  Usually it will be
 293  * used like this:
 294  *    $name = optional_param('name', 'Fred');
 295  *
 296  * @param string $parname the name of the page parameter we want
 297  * @param mixed  $default the default value to return if nothing is found
 298  * @param int $type expected type of parameter
 299  * @return mixed
 300  */
 301 function optional_param($parname, $default=NULL, $type=PARAM_CLEAN) {
 302
 303     // detect_unchecked_vars addition
 304     global $CFG;
 305     if (!empty($CFG->detect_unchecked_vars)) {
 306         global $UNCHECKED_VARS;
 307         unset ($UNCHECKED_VARS->vars[$parname]);
 308     }
 309
 310     if (isset($_POST[$parname])) {       // POST has precedence
 311         $param = $_POST[$parname];
 312     } else if (isset($_GET[$parname])) {
 313         $param = $_GET[$parname];
 314     } else {
 315         return $default;
 316     }
 317
 318     return clean_param($param, $type);
 319 }
 320
 321 /**
 322  * Used by {@link optional_param()} and {@link required_param()} to
 323  * clean the variables and/or cast to specific types, based on
 324  * an options field.
 325  * <code>
 326  * $course->format = clean_param($course->format, PARAM_ALPHA);
 327  * $selectedgrade_item = clean_param($selectedgrade_item, PARAM_CLEAN);
 328  * </code>
 329  *
 330  * @uses $CFG
 331  * @uses PARAM_CLEAN
 332  * @uses PARAM_INT
 333  * @uses PARAM_INTEGER
 334  * @uses PARAM_ALPHA
 335  * @uses PARAM_ALPHANUM
 336  * @uses PARAM_NOTAGS
 337  * @uses PARAM_ALPHAEXT
 338  * @uses PARAM_BOOL
 339  * @uses PARAM_SAFEDIR
 340  * @uses PARAM_CLEANFILE
 341  * @uses PARAM_FILE
 342  * @uses PARAM_PATH
 343  * @uses PARAM_HOST
 344  * @uses PARAM_URL
 345  * @uses PARAM_LOCALURL
 346  * @uses PARAM_CLEANHTML
 347  * @uses PARAM_SEQUENCE
 348  * @param mixed $param the variable we are cleaning
 349  * @param int $type expected format of param after cleaning.
 350  * @return mixed
 351  */
 352 function clean_param($param, $type) {
 353
 354     global $CFG;
 355
 356     if (is_array($param)) {              // Let's loop
 357         $newparam = array();
 358         foreach ($param as $key => $value) {
 359             $newparam[$key] = clean_param($value, $type);
 360         }
 361         return $newparam;
 362     }
 363
 364     switch ($type) {
 365         case PARAM_RAW:          // no cleaning at all
 366             return $param;
 367
 368         case PARAM_CLEAN:        // General HTML cleaning, try to use more specific type if possible
 369             if (is_numeric($param)) {
 370                 return $param;
 371             }
 372             $param = stripslashes($param);   // Needed for kses to work fine
 373             $param = clean_text($param);     // Sweep for scripts, etc
 374             return addslashes($param);       // Restore original request parameter slashes
 375
 376         case PARAM_CLEANHTML:    // prepare html fragment for display, do not store it into db!!
 377             $param = stripslashes($param);   // Remove any slashes
 378             $param = clean_text($param);     // Sweep for scripts, etc
 379             return trim($param);
 380
 381         case PARAM_INT:
 382             return (int)$param;  // Convert to integer
 383
 384         case PARAM_NUMBER:
 385             return (float)$param;  // Convert to integer
 386
 387         case PARAM_ALPHA:        // Remove everything not a-z
 388             return eregi_replace('[^a-zA-Z]', '', $param);
 389
 390         case PARAM_ALPHANUM:     // Remove everything not a-zA-Z0-9
 391             return eregi_replace('[^A-Za-z0-9]', '', $param);
 392
 393         case PARAM_ALPHAEXT:     // Remove everything not a-zA-Z/_-
 394             return eregi_replace('[^a-zA-Z/_-]', '', $param);
 395
 396         case PARAM_SEQUENCE:     // Remove everything not 0-9,
 397             return eregi_replace('[^0-9,]', '', $param);
 398
 399         case PARAM_BOOL:         // Convert to 1 or 0
 400             $tempstr = strtolower($param);
 401             if ($tempstr == 'on' or $tempstr == 'yes' ) {
 402                 $param = 1;
 403             } else if ($tempstr == 'off' or $tempstr == 'no') {
 404                 $param = 0;
 405             } else {
 406                 $param = empty($param) ? 0 : 1;
 407             }
 408             return $param;
 409
 410         case PARAM_NOTAGS:       // Strip all tags
 411             return strip_tags($param);
 412
 413         case PARAM_TEXT:    // leave only tags needed for multilang
 414             return clean_param(strip_tags($param, '<lang><span>'), PARAM_CLEAN);
 415
 416         case PARAM_SAFEDIR:      // Remove everything not a-zA-Z0-9_-
 417             return eregi_replace('[^a-zA-Z0-9_-]', '', $param);
 418
 419         case PARAM_CLEANFILE:    // allow only safe characters
 420             return clean_filename($param);
 421
 422         case PARAM_FILE:         // Strip all suspicious characters from filename
 423             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':\\/]', '', $param);
 424             $param = ereg_replace('\.\.+', '', $param);
 425             if($param == '.') {
 426                 $param = '';
 427             }
 428             return $param;
 429
 430         case PARAM_PATH:         // Strip all suspicious characters from file path
 431             $param = str_replace('\\\'', '\'', $param);
 432             $param = str_replace('\\"', '"', $param);
 433             $param = str_replace('\\', '/', $param);
 434             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':]', '', $param);
 435             $param = ereg_replace('\.\.+', '', $param);
 436             $param = ereg_replace('//+', '/', $param);
 437             return ereg_replace('/(\./)+', '/', $param);
 438
 439         case PARAM_HOST:         // allow FQDN or IPv4 dotted quad
 440             preg_replace('/[^\.\d\w-]/','', $param ); // only allowed chars
 441             // match ipv4 dotted quad
 442             if (preg_match('/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/',$param, $match)){
 443                 // confirm values are ok
 444                 if ( $match[0] > 255
 445                      || $match[1] > 255
 446                      || $match[3] > 255
 447                      || $match[4] > 255 ) {
 448                     // hmmm, what kind of dotted quad is this?
 449                     $param = '';
 450                 }
 451             } elseif ( preg_match('/^[\w\d\.-]+$/', $param) // dots, hyphens, numbers
 452                        && !preg_match('/^[\.-]/',  $param) // no leading dots/hyphens
 453                        && !preg_match('/[\.-]$/',  $param) // no trailing dots/hyphens
 454                        ) {
 455                 // all is ok - $param is respected
 456             } else {
 457                 // all is not ok...
 458                 $param='';
 459             }
 460             return $param;
 461
 462         case PARAM_URL:          // allow safe ftp, http, mailto urls
 463             include_once($CFG->dirroot . '/lib/validateurlsyntax.php');
 464             if (!empty($param) && validateUrlSyntax($param, 's?H?S?F?E?u-P-a?I?p?f?q?r?')) {
 465                 // all is ok, param is respected
 466             } else {
 467                 $param =''; // not really ok
 468             }
 469             return $param;
 470
 471         case PARAM_LOCALURL:     // allow http absolute, root relative and relative URLs within wwwroot
 472             $param = clean_param($param, PARAM_URL);
 473             if (!empty($param)) {
 474                 if (preg_match(':^/:', $param)) {
 475                     // root-relative, ok!
 476                 } elseif (preg_match('/^'.preg_quote($CFG->wwwroot, '/').'/i',$param)) {
 477                     // absolute, and matches our wwwroot
 478                 } else {
 479                     // relative - let's make sure there are no tricks
 480                     if (validateUrlSyntax($param, 's-u-P-a-p-f+q?r?')) {
 481                         // looks ok.
 482                     } else {
 483                         $param = '';
 484                     }
 485                 }
 486             }
 487             return $param;
 488         case PARAM_PEM:
 489             $param = trim($param);
 490             // PEM formatted strings may contain letters/numbers and the symbols
 491             // forward slash: /
 492             // plus sign:     +
 493             // equal sign:    =
 494             // , surrounded by BEGIN and END CERTIFICATE prefix and suffixes
 495             if (preg_match('/^-----BEGIN CERTIFICATE-----([\s\w\/\+=]+)-----END CERTIFICATE-----$/', trim($param), $matches)) {
 496                 list($wholething, $body) = $matches;
 497                 unset($wholething, $matches);
 498                 $b64 = clean_param($body, PARAM_BASE64);
 499                 if (!empty($b64)) {
 500                     return "-----BEGIN CERTIFICATE-----\n$b64\n-----END CERTIFICATE-----\n";
 501                 } else {
 502                     return '';
 503                 }
 504             }
 505             return '';
 506         case PARAM_BASE64:
 507             if (!empty($param)) {
 508                 // PEM formatted strings may contain letters/numbers and the symbols
 509                 // forward slash: /
 510                 // plus sign:     +
 511                 // equal sign:    =
 512                 if (0 >= preg_match('/^([\s\w\/\+=]+)$/', trim($param))) {
 513                     return '';
 514                 }
 515                 $lines = preg_split('/[\s]+/', $param, -1, PREG_SPLIT_NO_EMPTY);
 516                 // Each line of base64 encoded data must be 64 characters in
 517                 // length, except for the last line which may be less than (or
 518                 // equal to) 64 characters long.
 519                 for ($i=0, $j=count($lines); $i < $j; $i++) {
 520                     if ($i + 1 == $j) {
 521                         if (64 < strlen($lines[$i])) {
 522                             return '';
 523                         }
 524                         continue;
 525                     }
 526
 527                     if (64 != strlen($lines[$i])) {
 528                         return '';
 529                     }
 530                 }
 531                 return implode("\n",$lines);
 532             } else {
 533                 return '';
 534             }
 535         default:                 // throw error, switched parameters in optional_param or another serious problem
 536             error("Unknown parameter type: $type");
 537     }
 538 }
 539
 540
 541
 542 /**
 543  * Set a key in global configuration
 544  *
 545  * Set a key/value pair in both this session's {@link $CFG} global variable
 546  * and in the 'config' database table for future sessions.
 547  *
 548  * Can also be used to update keys for plugin-scoped configs in config_plugin table.
 549  * In that case it doesn't affect $CFG.
 550  *
 551  * @param string $name the key to set
 552  * @param string $value the value to set (without magic quotes)
 553  * @param string $plugin (optional) the plugin scope
 554  * @uses $CFG
 555  * @return bool
 556  */
 557 function set_config($name, $value, $plugin=NULL) {
 558 /// No need for get_config because they are usually always available in $CFG
 559
 560     global $CFG;
 561
 562     if (empty($plugin)) {
 563         $CFG->$name = $value;  // So it's defined for this invocation at least
 564
 565         if (get_field('config', 'name', 'name', $name)) {
 566             return set_field('config', 'value', addslashes($value), 'name', $name);
 567         } else {
 568             $config = new object();
 569             $config->name = $name;
 570             $config->value = addslashes($value);
 571             return insert_record('config', $config);
 572         }
 573     } else { // plugin scope
 574         if ($id = get_field('config_plugins', 'id', 'name', $name, 'plugin', $plugin)) {
 575             return set_field('config_plugins', 'value', addslashes($value), 'id', $id);
 576         } else {
 577             $config = new object();
 578             $config->plugin = addslashes($plugin);
 579             $config->name   = $name;
 580             $config->value  = addslashes($value);
 581             return insert_record('config_plugins', $config);
 582         }
 583     }
 584 }
 585
 586 /**
 587  * Get configuration values from the global config table
 588  * or the config_plugins table.
 589  *
 590  * If called with no parameters it will do the right thing
 591  * generating $CFG safely from the database without overwriting
 592  * existing values.
 593  *
 594  * If called with 2 parameters it will return a $string single
 595  * value or false of the value is not found.
 596  *
 597  * @param string $plugin
 598  * @param string $name
 599  * @uses $CFG
 600  * @return hash-like object or single value
 601  *
 602  */
 603 function get_config($plugin=NULL, $name=NULL) {
 604
 605     global $CFG;
 606
 607     if (!empty($name)) { // the user is asking for a specific value
 608         if (!empty($plugin)) {
 609             return get_field('config_plugins', 'value', 'plugin' , $plugin, 'name', $name);
 610         } else {
 611             return get_field('config', 'value', 'name', $name);
 612         }
 613     }
 614
 615     // the user is after a recordset
 616     if (!empty($plugin)) {
 617         if ($configs=get_records('config_plugins', 'plugin', $plugin, '', 'name,value')) {
 618             $configs = (array)$configs;
 619             $localcfg = array();
 620             foreach ($configs as $config) {
 621                 $localcfg[$config->name] = $config->value;
 622             }
 623             return (object)$localcfg;
 624         } else {
 625             return false;
 626         }
 627     } else {
 628         // this was originally in setup.php
 629         if ($configs = get_records('config')) {
 630             $localcfg = (array)$CFG;
 631             foreach ($configs as $config) {
 632                 if (!isset($localcfg[$config->name])) {
 633                     $localcfg[$config->name] = $config->value;
 634                 } else {
 635                     if ($localcfg[$config->name] != $config->value ) {
 636                         // complain if the DB has a different
 637                         // value than config.php does
 638                         error_log("\$CFG->{$config->name} in config.php ({$localcfg[$config->name]}) overrides database setting ({$config->value})");
 639                     }
 640                 }
 641             }
 642
 643             $localcfg = (object)$localcfg;
 644             return $localcfg;
 645         } else {
 646             // preserve $CFG if DB returns nothing or error
 647             return $CFG;
 648         }
 649
 650     }
 651 }
 652
 653 /**
 654  * Removes a key from global configuration
 655  *
 656  * @param string $name the key to set
 657  * @param string $plugin (optional) the plugin scope
 658  * @uses $CFG
 659  * @return bool
 660  */
 661 function unset_config($name, $plugin=NULL) {
 662
 663     global $CFG;
 664
 665     unset($CFG->$name);
 666
 667     if (empty($plugin)) {
 668         return delete_records('config', 'name', $name);
 669     } else {
 670         return delete_records('config_plugins', 'name', $name, 'plugin', $plugin);
 671     }
 672 }
 673
 674
 675 /**
 676  * Refresh current $USER session global variable with all their current preferences.
 677  * @uses $USER
 678  */
 679 function reload_user_preferences() {
 680
 681     global $USER;
 682
 683     //reset preference
 684     $USER->preference = array();
 685
 686     if (!isloggedin() or isguestuser()) {
 687         // no pernament storage for not-logged-in user and guest
 688
 689     } else if ($preferences = get_records('user_preferences', 'userid', $USER->id)) {
 690         foreach ($preferences as $preference) {
 691             $USER->preference[$preference->name] = $preference->value;
 692         }
 693     }
 694
 695     return true;
 696 }
 697
 698 /**
 699  * Sets a preference for the current user
 700  * Optionally, can set a preference for a different user object
 701  * @uses $USER
 702  * @todo Add a better description and include usage examples. Add inline links to $USER and user functions in above line.
 703
 704  * @param string $name The key to set as preference for the specified user
 705  * @param string $value The value to set forthe $name key in the specified user's record
 706  * @param int $otheruserid A moodle user ID
 707  * @return bool
 708  */
 709 function set_user_preference($name, $value, $otheruserid=NULL) {
 710
 711     global $USER;
 712
 713     if (!isset($USER->preference)) {
 714         reload_user_preferences();
 715     }
 716
 717     if (empty($name)) {
 718         return false;
 719     }
 720
 721     $nostore = false;
 722
 723     if (empty($otheruserid)){
 724         if (!isloggedin() or isguestuser()) {
 725             $nostore = true;
 726         }
 727         $userid = $USER->id;
 728     } else {
 729         if (isguestuser($otheruserid)) {
 730             $nostore = true;
 731         }
 732         $userid = $otheruserid;
 733     }
 734
 735     $return = true;
 736     if ($nostore) {
 737         // no pernament storage for not-logged-in user and guest
 738
 739     } else if ($preference = get_record('user_preferences', 'userid', $userid, 'name', addslashes($name))) {
 740         if (!set_field('user_preferences', 'value', addslashes((string)$value), 'id', $preference->id)) {
 741             $return = false;
 742         }
 743
 744     } else {
 745         $preference = new object();
 746         $preference->userid = $userid;
 747         $preference->name   = addslashes($name);
 748         $preference->value  = addslashes((string)$value);
 749         if (!insert_record('user_preferences', $preference)) {
 750             $return = false;
 751         }
 752     }
 753
 754     // update value in USER session if needed
 755     if ($userid == $USER->id) {
 756         $USER->preference[$name] = (string)$value;
 757     }
 758
 759     return $return;
 760 }
 761
 762 /**
 763  * Unsets a preference completely by deleting it from the database
 764  * Optionally, can set a preference for a different user id
 765  * @uses $USER
 766  * @param string  $name The key to unset as preference for the specified user
 767  * @param int $otheruserid A moodle user ID
 768  */
 769 function unset_user_preference($name, $otheruserid=NULL) {
 770
 771     global $USER;
 772
 773     if (!isset($USER->preference)) {
 774         reload_user_preferences();
 775     }
 776
 777     if (empty($otheruserid)){
 778         $userid = $USER->id;
 779     } else {
 780         $userid = $otheruserid;
 781     }
 782
 783     //Delete the preference from $USER if needed
 784     if ($userid == $USER->id) {
 785         unset($USER->preference[$name]);
 786     }
 787
 788     //Then from DB
 789     return delete_records('user_preferences', 'userid', $userid, 'name', addslashes($name));
 790 }
 791
 792
 793 /**
 794  * Sets a whole array of preferences for the current user
 795  * @param array $prefarray An array of key/value pairs to be set
 796  * @param int $otheruserid A moodle user ID
 797  * @return bool
 798  */
 799 function set_user_preferences($prefarray, $otheruserid=NULL) {
 800
 801     if (!is_array($prefarray) or empty($prefarray)) {
 802         return false;
 803     }
 804
 805     $return = true;
 806     foreach ($prefarray as $name => $value) {
 807         // The order is important; test for return is done first
 808         $return = (set_user_preference($name, $value, $otheruserid) && $return);
 809     }
 810     return $return;
 811 }
 812
 813 /**
 814  * If no arguments are supplied this function will return
 815  * all of the current user preferences as an array.
 816  * If a name is specified then this function
 817  * attempts to return that particular preference value.  If
 818  * none is found, then the optional value $default is returned,
 819  * otherwise NULL.
 820  * @param string $name Name of the key to use in finding a preference value
 821  * @param string $default Value to be returned if the $name key is not set in the user preferences
 822  * @param int $otheruserid A moodle user ID
 823  * @uses $USER
 824  * @return string
 825  */
 826 function get_user_preferences($name=NULL, $default=NULL, $otheruserid=NULL) {
 827     global $USER;
 828
 829     if (!isset($USER->preference)) {
 830         reload_user_preferences();
 831     }
 832
 833     if (empty($otheruserid)){
 834         $userid = $USER->id;
 835     } else {
 836         $userid = $otheruserid;
 837     }
 838
 839     if ($userid == $USER->id) {
 840         $preference = $USER->preference;
 841
 842     } else {
 843         $preference = array();
 844         if ($prefdata = get_records('user_preferences', 'userid', $userid)) {
 845             foreach ($prefdata as $pref) {
 846                 $preference[$pref->name] = $pref->value;
 847             }
 848         }
 849     }
 850
 851     if (empty($name)) {
 852         return $preference;            // All values
 853
 854     } else if (array_key_exists($name, $preference)) {
 855         return $preference[$name];    // The single value
 856
 857     } else {
 858         return $default;              // Default value (or NULL)
 859     }
 860 }
 861
 862
 863 /// FUNCTIONS FOR HANDLING TIME ////////////////////////////////////////////
 864
 865 /**
 866  * Given date parts in user time produce a GMT timestamp.
 867  *
 868  * @param int $year The year part to create timestamp of
 869  * @param int $month The month part to create timestamp of
 870  * @param int $day The day part to create timestamp of
 871  * @param int $hour The hour part to create timestamp of
 872  * @param int $minute The minute part to create timestamp of
 873  * @param int $second The second part to create timestamp of
 874  * @param float $timezone ?
 875  * @param bool $applydst ?
 876  * @return int timestamp
 877  * @todo Finish documenting this function
 878  */
 879 function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0, $timezone=99, $applydst=true) {
 880
 881     $timezone = get_user_timezone_offset($timezone);
 882
 883     if (abs($timezone) > 13) {
 884         $time = mktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 885     } else {
 886         $time = gmmktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 887         $time = usertime($time, $timezone);
 888         if($applydst) {
 889             $time -= dst_offset_on($time);
 890         }
 891     }
 892
 893     return $time;
 894
 895 }
 896
 897 /**
 898  * Given an amount of time in seconds, returns string
 899  * formatted nicely as weeks, days, hours etc as needed
 900  *
 901  * @uses MINSECS
 902  * @uses HOURSECS
 903  * @uses DAYSECS
 904  * @uses YEARSECS
 905  * @param int $totalsecs ?
 906  * @param array $str ?
 907  * @return string
 908  */
 909  function format_time($totalsecs, $str=NULL) {
 910
 911     $totalsecs = abs($totalsecs);
 912
 913     if (!$str) {  // Create the str structure the slow way
 914         $str->day   = get_string('day');
 915         $str->days  = get_string('days');
 916         $str->hour  = get_string('hour');
 917         $str->hours = get_string('hours');
 918         $str->min   = get_string('min');
 919         $str->mins  = get_string('mins');
 920         $str->sec   = get_string('sec');
 921         $str->secs  = get_string('secs');
 922         $str->year  = get_string('year');
 923         $str->years = get_string('years');
 924     }
 925
 926
 927     $years     = floor($totalsecs/YEARSECS);
 928     $remainder = $totalsecs - ($years*YEARSECS);
 929     $days      = floor($remainder/DAYSECS);
 930     $remainder = $totalsecs - ($days*DAYSECS);
 931     $hours     = floor($remainder/HOURSECS);
 932     $remainder = $remainder - ($hours*HOURSECS);
 933     $mins      = floor($remainder/MINSECS);
 934     $secs      = $remainder - ($mins*MINSECS);
 935
 936     $ss = ($secs == 1)  ? $str->sec  : $str->secs;
 937     $sm = ($mins == 1)  ? $str->min  : $str->mins;
 938     $sh = ($hours == 1) ? $str->hour : $str->hours;
 939     $sd = ($days == 1)  ? $str->day  : $str->days;
 940     $sy = ($years == 1)  ? $str->year  : $str->years;
 941
 942     $oyears = '';
 943     $odays = '';
 944     $ohours = '';
 945     $omins = '';
 946     $osecs = '';
 947
 948     if ($years)  $oyears  = $years .' '. $sy;
 949     if ($days)  $odays  = $days .' '. $sd;
 950     if ($hours) $ohours = $hours .' '. $sh;
 951     if ($mins)  $omins  = $mins .' '. $sm;
 952     if ($secs)  $osecs  = $secs .' '. $ss;
 953
 954     if ($years) return trim($oyears .' '. $odays);
 955     if ($days)  return trim($odays .' '. $ohours);
 956     if ($hours) return trim($ohours .' '. $omins);
 957     if ($mins)  return trim($omins .' '. $osecs);
 958     if ($secs)  return $osecs;
 959     return get_string('now');
 960 }
 961
 962 /**
 963  * Returns a formatted string that represents a date in user time
 964  * <b>WARNING: note that the format is for strftime(), not date().</b>
 965  * Because of a bug in most Windows time libraries, we can't use
 966  * the nicer %e, so we have to use %d which has leading zeroes.
 967  * A lot of the fuss in the function is just getting rid of these leading
 968  * zeroes as efficiently as possible.
 969  *
 970  * If parameter fixday = true (default), then take off leading
 971  * zero from %d, else mantain it.
 972  *
 973  * @uses HOURSECS
 974  * @param  int $date timestamp in GMT
 975  * @param string $format strftime format
 976  * @param float $timezone
 977  * @param bool $fixday If true (default) then the leading
 978  * zero from %d is removed. If false then the leading zero is mantained.
 979  * @return string
 980  */
 981 function userdate($date, $format='', $timezone=99, $fixday = true) {
 982
 983     global $CFG;
 984
 985     if (empty($format)) {
 986         $format = get_string('strftimedaydatetime');
 987     }
 988
 989     if (!empty($CFG->nofixday)) {  // Config.php can force %d not to be fixed.
 990         $fixday = false;
 991     } else if ($fixday) {
 992         $formatnoday = str_replace('%d', 'DD', $format);
 993         $fixday = ($formatnoday != $format);
 994     }
 995
 996     $date += dst_offset_on($date);
 997
 998     $timezone = get_user_timezone_offset($timezone);
 999
1000     if (abs($timezone) > 13) {   /// Server time
1001         if ($fixday) {
1002             $datestring = strftime($formatnoday, $date);
1003             $daystring  = str_replace(' 0', '', strftime(' %d', $date));
1004             $datestring = str_replace('DD', $daystring, $datestring);
1005         } else {
1006             $datestring = strftime($format, $date);
1007         }
1008     } else {
1009         $date += (int)($timezone * 3600);
1010         if ($fixday) {
1011             $datestring = gmstrftime($formatnoday, $date);
1012             $daystring  = str_replace(' 0', '', gmstrftime(' %d', $date));
1013             $datestring = str_replace('DD', $daystring, $datestring);
1014         } else {
1015             $datestring = gmstrftime($format, $date);
1016         }
1017     }
1018
1019 /// If we are running under Windows convert from windows encoding to UTF-8
1020 /// (because it's impossible to specify UTF-8 to fetch locale info in Win32)
1021
1022    if ($CFG->ostype == 'WINDOWS') {
1023        if ($localewincharset = get_string('localewincharset')) {
1024            $textlib = textlib_get_instance();
1025            $datestring = $textlib->convert($datestring, $localewincharset, 'utf-8');
1026        }
1027    }
1028
1029     return $datestring;
1030 }
1031
1032 /**
1033  * Given a $time timestamp in GMT (seconds since epoch),
1034  * returns an array that represents the date in user time
1035  *
1036  * @uses HOURSECS
1037  * @param int $time Timestamp in GMT
1038  * @param float $timezone ?
1039  * @return array An array that represents the date in user time
1040  * @todo Finish documenting this function
1041  */
1042 function usergetdate($time, $timezone=99) {
1043
1044     $timezone = get_user_timezone_offset($timezone);
1045
1046     if (abs($timezone) > 13) {    // Server time
1047         return getdate($time);
1048     }
1049
1050     // There is no gmgetdate so we use gmdate instead
1051     $time += dst_offset_on($time);
1052     $time += intval((float)$timezone * HOURSECS);
1053
1054     $datestring = gmstrftime('%S_%M_%H_%d_%m_%Y_%w_%j_%A_%B', $time);
1055
1056     list(
1057         $getdate['seconds'],
1058         $getdate['minutes'],
1059         $getdate['hours'],
1060         $getdate['mday'],
1061         $getdate['mon'],
1062         $getdate['year'],
1063         $getdate['wday'],
1064         $getdate['yday'],
1065         $getdate['weekday'],
1066         $getdate['month']
1067     ) = explode('_', $datestring);
1068
1069     return $getdate;
1070 }
1071
1072 /**
1073  * Given a GMT timestamp (seconds since epoch), offsets it by
1074  * the timezone.  eg 3pm in India is 3pm GMT - 7 * 3600 seconds
1075  *
1076  * @uses HOURSECS
1077  * @param  int $date Timestamp in GMT
1078  * @param float $timezone
1079  * @return int
1080  */
1081 function usertime($date, $timezone=99) {
1082
1083     $timezone = get_user_timezone_offset($timezone);
1084
1085     if (abs($timezone) > 13) {
1086         return $date;
1087     }
1088     return $date - (int)($timezone * HOURSECS);
1089 }
1090
1091 /**
1092  * Given a time, return the GMT timestamp of the most recent midnight
1093  * for the current user.
1094  *
1095  * @param int $date Timestamp in GMT
1096  * @param float $timezone ?
1097  * @return ?
1098  */
1099 function usergetmidnight($date, $timezone=99) {
1100
1101     $timezone = get_user_timezone_offset($timezone);
1102     $userdate = usergetdate($date, $timezone);
1103
1104     // Time of midnight of this user's day, in GMT
1105     return make_timestamp($userdate['year'], $userdate['mon'], $userdate['mday'], 0, 0, 0, $timezone);
1106
1107 }
1108
1109 /**
1110  * Returns a string that prints the user's timezone
1111  *
1112  * @param float $timezone The user's timezone
1113  * @return string
1114  */
1115 function usertimezone($timezone=99) {
1116
1117     $tz = get_user_timezone($timezone);
1118
1119     if (!is_float($tz)) {
1120         return $tz;
1121     }
1122
1123     if(abs($tz) > 13) { // Server time
1124         return get_string('serverlocaltime');
1125     }
1126
1127     if($tz == intval($tz)) {
1128         // Don't show .0 for whole hours
1129         $tz = intval($tz);
1130     }
1131
1132     if($tz == 0) {
1133         return 'GMT';
1134     }
1135     else if($tz > 0) {
1136         return 'GMT+'.$tz;
1137     }
1138     else {
1139         return 'GMT'.$tz;
1140     }
1141
1142 }
1143
1144 /**
1145  * Returns a float which represents the user's timezone difference from GMT in hours
1146  * Checks various settings and picks the most dominant of those which have a value
1147  *
1148  * @uses $CFG
1149  * @uses $USER
1150  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1151  * @return int
1152  */
1153 function get_user_timezone_offset($tz = 99) {
1154
1155     global $USER, $CFG;
1156
1157     $tz = get_user_timezone($tz);
1158
1159     if (is_float($tz)) {
1160         return $tz;
1161     } else {
1162         $tzrecord = get_timezone_record($tz);
1163         if (empty($tzrecord)) {
1164             return 99.0;
1165         }
1166         return (float)$tzrecord->gmtoff / HOURMINS;
1167     }
1168 }
1169
1170 /**
1171  * Returns a float or a string which denotes the user's timezone
1172  * A float value means that a simple offset from GMT is used, while a string (it will be the name of a timezone in the database)
1173  * means that for this timezone there are also DST rules to be taken into account
1174  * Checks various settings and picks the most dominant of those which have a value
1175  *
1176  * @uses $USER
1177  * @uses $CFG
1178  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1179  * @return mixed
1180  */
1181 function get_user_timezone($tz = 99) {
1182     global $USER, $CFG;
1183
1184     $timezones = array(
1185         $tz,
1186         isset($CFG->forcetimezone) ? $CFG->forcetimezone : 99,
1187         isset($USER->timezone) ? $USER->timezone : 99,
1188         isset($CFG->timezone) ? $CFG->timezone : 99,
1189         );
1190
1191     $tz = 99;
1192
1193     while(($tz == '' || $tz == 99) && $next = each($timezones)) {
1194         $tz = $next['value'];
1195     }
1196
1197     return is_numeric($tz) ? (float) $tz : $tz;
1198 }
1199
1200 /**
1201  * ?
1202  *
1203  * @uses $CFG
1204  * @uses $db
1205  * @param string $timezonename ?
1206  * @return object
1207  */
1208 function get_timezone_record($timezonename) {
1209     global $CFG, $db;
1210     static $cache = NULL;
1211
1212     if ($cache === NULL) {
1213         $cache = array();
1214     }
1215
1216     if (isset($cache[$timezonename])) {
1217         return $cache[$timezonename];
1218     }
1219
1220     return $cache[$timezonename] = get_record_sql('SELECT * FROM '.$CFG->prefix.'timezone
1221                                       WHERE name = '.$db->qstr($timezonename).' ORDER BY year DESC', true);
1222 }
1223
1224 /**
1225  * ?
1226  *
1227  * @uses $CFG
1228  * @uses $USER
1229  * @param ? $fromyear ?
1230  * @param ? $to_year ?
1231  * @return bool
1232  */
1233 function calculate_user_dst_table($from_year = NULL, $to_year = NULL) {
1234     global $CFG, $SESSION;
1235
1236     $usertz = get_user_timezone();
1237
1238     if (is_float($usertz)) {
1239         // Trivial timezone, no DST
1240         return false;
1241     }
1242
1243     if (!empty($SESSION->dst_offsettz) && $SESSION->dst_offsettz != $usertz) {
1244         // We have precalculated values, but the user's effective TZ has changed in the meantime, so reset
1245         unset($SESSION->dst_offsets);
1246         unset($SESSION->dst_range);
1247     }
1248
1249     if (!empty($SESSION->dst_offsets) && empty($from_year) && empty($to_year)) {
1250         // Repeat calls which do not request specific year ranges stop here, we have already calculated the table
1251         // This will be the return path most of the time, pretty light computationally
1252         return true;
1253     }
1254
1255     // Reaching here means we either need to extend our table or create it from scratch
1256
1257     // Remember which TZ we calculated these changes for
1258     $SESSION->dst_offsettz = $usertz;
1259
1260     if(empty($SESSION->dst_offsets)) {
1261         // If we 're creating from scratch, put the two guard elements in there
1262         $SESSION->dst_offsets = array(1 => NULL, 0 => NULL);
1263     }
1264     if(empty($SESSION->dst_range)) {
1265         // If creating from scratch
1266         $from = max((empty($from_year) ? intval(date('Y')) - 3 : $from_year), 1971);
1267         $to   = min((empty($to_year)   ? intval(date('Y')) + 3 : $to_year),   2035);
1268
1269         // Fill in the array with the extra years we need to process
1270         $yearstoprocess = array();
1271         for($i = $from; $i <= $to; ++$i) {
1272             $yearstoprocess[] = $i;
1273         }
1274
1275         // Take note of which years we have processed for future calls
1276         $SESSION->dst_range = array($from, $to);
1277     }
1278     else {
1279         // If needing to extend the table, do the same
1280         $yearstoprocess = array();
1281
1282         $from = max((empty($from_year) ? $SESSION->dst_range[0] : $from_year), 1971);
1283         $to   = min((empty($to_year)   ? $SESSION->dst_range[1] : $to_year),   2035);
1284
1285         if($from < $SESSION->dst_range[0]) {
1286             // Take note of which years we need to process and then note that we have processed them for future calls
1287             for($i = $from; $i < $SESSION->dst_range[0]; ++$i) {
1288                 $yearstoprocess[] = $i;
1289             }
1290             $SESSION->dst_range[0] = $from;
1291         }
1292         if($to > $SESSION->dst_range[1]) {
1293             // Take note of which years we need to process and then note that we have processed them for future calls
1294             for($i = $SESSION->dst_range[1] + 1; $i <= $to; ++$i) {
1295                 $yearstoprocess[] = $i;
1296             }
1297             $SESSION->dst_range[1] = $to;
1298         }
1299     }
1300
1301     if(empty($yearstoprocess)) {
1302         // This means that there was a call requesting a SMALLER range than we have already calculated
1303         return true;
1304     }
1305
1306     // From now on, we know that the array has at least the two guard elements, and $yearstoprocess has the years we need
1307     // Also, the array is sorted in descending timestamp order!
1308
1309     // Get DB data
1310     $presetrecords = get_records('timezone', 'name', $usertz, 'year DESC', 'year, gmtoff, dstoff, dst_month, dst_startday, dst_weekday, dst_skipweeks, dst_time, std_month, std_startday, std_weekday, std_skipweeks, std_time');
1311     if(empty($presetrecords)) {
1312         return false;
1313     }
1314
1315     // Remove ending guard (first element of the array)
1316     reset($SESSION->dst_offsets);
1317     unset($SESSION->dst_offsets[key($SESSION->dst_offsets)]);
1318
1319     // Add all required change timestamps
1320     foreach($yearstoprocess as $y) {
1321         // Find the record which is in effect for the year $y
1322         foreach($presetrecords as $year => $preset) {
1323             if($year <= $y) {
1324                 break;
1325             }
1326         }
1327
1328         $changes = dst_changes_for_year($y, $preset);
1329
1330         if($changes === NULL) {
1331             continue;
1332         }
1333         if($changes['dst'] != 0) {
1334             $SESSION->dst_offsets[$changes['dst']] = $preset->dstoff * MINSECS;
1335         }
1336         if($changes['std'] != 0) {
1337             $SESSION->dst_offsets[$changes['std']] = 0;
1338         }
1339     }
1340
1341     // Put in a guard element at the top
1342     $maxtimestamp = max(array_keys($SESSION->dst_offsets));
1343     $SESSION->dst_offsets[($maxtimestamp + DAYSECS)] = NULL; // DAYSECS is arbitrary, any "small" number will do
1344
1345     // Sort again
1346     krsort($SESSION->dst_offsets);
1347
1348     return true;
1349 }
1350
1351 function dst_changes_for_year($year, $timezone) {
1352
1353     if($timezone->dst_startday == 0 && $timezone->dst_weekday == 0 && $timezone->std_startday == 0 && $timezone->std_weekday == 0) {
1354         return NULL;
1355     }
1356
1357     $monthdaydst = find_day_in_month($timezone->dst_startday, $timezone->dst_weekday, $timezone->dst_month, $year);
1358     $monthdaystd = find_day_in_month($timezone->std_startday, $timezone->std_weekday, $timezone->std_month, $year);
1359
1360     list($dst_hour, $dst_min) = explode(':', $timezone->dst_time);
1361     list($std_hour, $std_min) = explode(':', $timezone->std_time);
1362
1363     $timedst = make_timestamp($year, $timezone->dst_month, $monthdaydst, 0, 0, 0, 99, false);
1364     $timestd = make_timestamp($year, $timezone->std_month, $monthdaystd, 0, 0, 0, 99, false);
1365
1366     // Instead of putting hour and minute in make_timestamp(), we add them afterwards.
1367     // This has the advantage of being able to have negative values for hour, i.e. for timezones
1368     // where GMT time would be in the PREVIOUS day than the local one on which DST changes.
1369
1370     $timedst += $dst_hour * HOURSECS + $dst_min * MINSECS;
1371     $timestd += $std_hour * HOURSECS + $std_min * MINSECS;
1372
1373     return array('dst' => $timedst, 0 => $timedst, 'std' => $timestd, 1 => $timestd);
1374 }
1375
1376 // $time must NOT be compensated at all, it has to be a pure timestamp
1377 function dst_offset_on($time) {
1378     global $SESSION;
1379
1380     if(!calculate_user_dst_table() || empty($SESSION->dst_offsets)) {
1381         return 0;
1382     }
1383
1384     reset($SESSION->dst_offsets);
1385     while(list($from, $offset) = each($SESSION->dst_offsets)) {
1386         if($from <= $time) {
1387             break;
1388         }
1389     }
1390
1391     // This is the normal return path
1392     if($offset !== NULL) {
1393         return $offset;
1394     }
1395
1396     // Reaching this point means we haven't calculated far enough, do it now:
1397     // Calculate extra DST changes if needed and recurse. The recursion always
1398     // moves toward the stopping condition, so will always end.
1399
1400     if($from == 0) {
1401         // We need a year smaller than $SESSION->dst_range[0]
1402         if($SESSION->dst_range[0] == 1971) {
1403             return 0;
1404         }
1405         calculate_user_dst_table($SESSION->dst_range[0] - 5, NULL);
1406         return dst_offset_on($time);
1407     }
1408     else {
1409         // We need a year larger than $SESSION->dst_range[1]
1410         if($SESSION->dst_range[1] == 2035) {
1411             return 0;
1412         }
1413         calculate_user_dst_table(NULL, $SESSION->dst_range[1] + 5);
1414         return dst_offset_on($time);
1415     }
1416 }
1417
1418 function find_day_in_month($startday, $weekday, $month, $year) {
1419
1420     $daysinmonth = days_in_month($month, $year);
1421
1422     if($weekday == -1) {
1423         // Don't care about weekday, so return:
1424         //    abs($startday) if $startday != -1
1425         //    $daysinmonth otherwise
1426         return ($startday == -1) ? $daysinmonth : abs($startday);
1427     }
1428
1429     // From now on we 're looking for a specific weekday
1430
1431     // Give "end of month" its actual value, since we know it
1432     if($startday == -1) {
1433         $startday = -1 * $daysinmonth;
1434     }
1435
1436     // Starting from day $startday, the sign is the direction
1437
1438     if($startday < 1) {
1439
1440         $startday = abs($startday);
1441         $lastmonthweekday  = strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1442
1443         // This is the last such weekday of the month
1444         $lastinmonth = $daysinmonth + $weekday - $lastmonthweekday;
1445         if($lastinmonth > $daysinmonth) {
1446             $lastinmonth -= 7;
1447         }
1448
1449         // Find the first such weekday <= $startday
1450         while($lastinmonth > $startday) {
1451             $lastinmonth -= 7;
1452         }
1453
1454         return $lastinmonth;
1455
1456     }
1457     else {
1458
1459         $indexweekday = strftime('%w', mktime(12, 0, 0, $month, $startday, $year, 0));
1460
1461         $diff = $weekday - $indexweekday;
1462         if($diff < 0) {
1463             $diff += 7;
1464         }
1465
1466         // This is the first such weekday of the month equal to or after $startday
1467         $firstfromindex = $startday + $diff;
1468
1469         return $firstfromindex;
1470
1471     }
1472 }
1473
1474 /**
1475  * Calculate the number of days in a given month
1476  *
1477  * @param int $month The month whose day count is sought
1478  * @param int $year The year of the month whose day count is sought
1479  * @return int
1480  */
1481 function days_in_month($month, $year) {
1482    return intval(date('t', mktime(12, 0, 0, $month, 1, $year, 0)));
1483 }
1484
1485 /**
1486  * Calculate the position in the week of a specific calendar day
1487  *
1488  * @param int $day The day of the date whose position in the week is sought
1489  * @param int $month The month of the date whose position in the week is sought
1490  * @param int $year The year of the date whose position in the week is sought
1491  * @return int
1492  */
1493 function dayofweek($day, $month, $year) {
1494     // I wonder if this is any different from
1495     // strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1496     return intval(date('w', mktime(12, 0, 0, $month, $day, $year, 0)));
1497 }
1498
1499 /// USER AUTHENTICATION AND LOGIN ////////////////////////////////////////
1500
1501 /**
1502  * Makes sure that $USER->sesskey exists, if $USER itself exists. It sets a new sesskey
1503  * if one does not already exist, but does not overwrite existing sesskeys. Returns the
1504  * sesskey string if $USER exists, or boolean false if not.
1505  *
1506  * @uses $USER
1507  * @return string
1508  */
1509 function sesskey() {
1510     global $USER;
1511
1512     if(!isset($USER)) {
1513         return false;
1514     }
1515
1516     if (empty($USER->sesskey)) {
1517         $USER->sesskey = random_string(10);
1518     }
1519
1520     return $USER->sesskey;
1521 }
1522
1523
1524 /**
1525  * For security purposes, this function will check that the currently
1526  * given sesskey (passed as a parameter to the script or this function)
1527  * matches that of the current user.
1528  *
1529  * @param string $sesskey optionally provided sesskey
1530  * @return bool
1531  */
1532 function confirm_sesskey($sesskey=NULL) {
1533     global $USER;
1534
1535     if (!empty($USER->ignoresesskey) || !empty($CFG->ignoresesskey)) {
1536         return true;
1537     }
1538
1539     if (empty($sesskey)) {
1540         $sesskey = required_param('sesskey', PARAM_RAW);  // Check script parameters
1541     }
1542
1543     if (!isset($USER->sesskey)) {
1544         return false;
1545     }
1546
1547     return ($USER->sesskey === $sesskey);
1548 }
1549
1550 /**
1551  * Setup all global $CFG course variables, set locale and also themes
1552  * This function can be used on pages that do not require login instead of require_login()
1553  *
1554  * @param mixed $courseorid id of the course or course object
1555  */
1556 function course_setup($courseorid=0) {
1557     global $COURSE, $CFG, $SITE;
1558
1559 /// Redefine global $COURSE if needed
1560     if (empty($courseorid)) {
1561         // no change in global $COURSE - for backwards compatibiltiy
1562         // if require_rogin() used after require_login($courseid);
1563     } else if (is_object($courseorid)) {
1564         $COURSE = clone($courseorid);
1565     } else {
1566         global $course; // used here only to prevent repeated fetching from DB - may be removed later
1567         if (!empty($course->id) and $course->id == SITEID) {
1568             $COURSE = clone($SITE);
1569         } else if (!empty($course->id) and $course->id == $courseorid) {
1570             $COURSE = clone($course);
1571         } else {
1572             if (!$COURSE = get_record('course', 'id', $courseorid)) {
1573                 error('Invalid course ID');
1574             }
1575         }
1576     }
1577
1578 /// set locale and themes
1579     moodle_setlocale();
1580     theme_setup();
1581
1582 }
1583
1584 /**
1585  * This function checks that the current user is logged in and has the
1586  * required privileges
1587  *
1588  * This function checks that the current user is logged in, and optionally
1589  * whether they are allowed to be in a particular course and view a particular
1590  * course module.
1591  * If they are not logged in, then it redirects them to the site login unless
1592  * $autologinguest is set and {@link $CFG}->autologinguests is set to 1 in which
1593  * case they are automatically logged in as guests.
1594  * If $courseid is given and the user is not enrolled in that course then the
1595  * user is redirected to the course enrolment page.
1596  * If $cm is given and the coursemodule is hidden and the user is not a teacher
1597  * in the course then the user is redirected to the course home page.
1598  *
1599  * @uses $CFG
1600  * @uses $SESSION
1601  * @uses $USER
1602  * @uses $FULLME
1603  * @uses SITEID
1604  * @uses $COURSE
1605  * @param mixed $courseorid id of the course or course object
1606  * @param bool $autologinguest
1607  * @param object $cm course module object
1608  */
1609 function require_login($courseorid=0, $autologinguest=true, $cm=null) {
1610
1611     global $CFG, $SESSION, $USER, $COURSE, $FULLME;
1612
1613 /// setup global $COURSE, themes, language and locale
1614     course_setup($courseorid);
1615
1616 /// If the user is not even logged in yet then make sure they are
1617     if (!isloggedin()) {
1618         //NOTE: $USER->site check was obsoleted by session test cookie,
1619         //      $USER->confirmed test is in login/index.php
1620         $SESSION->wantsurl = $FULLME;
1621         if (!empty($_SERVER['HTTP_REFERER'])) {
1622             $SESSION->fromurl  = $_SERVER['HTTP_REFERER'];
1623         }
1624         if ($autologinguest and !empty($CFG->guestloginbutton) and !empty($CFG->autologinguests) and ($COURSE->id == SITEID or $COURSE->guest) ) {
1625             $loginguest = '?loginguest=true';
1626         } else {
1627             $loginguest = '';
1628         }
1629         if (empty($CFG->loginhttps) or $loginguest) { //do not require https for guest logins
1630             redirect($CFG->wwwroot .'/login/index.php'. $loginguest);
1631         } else {
1632             $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1633             redirect($wwwroot .'/login/index.php');
1634         }
1635         exit;
1636     }
1637
1638 /// loginas as redirection if needed
1639     if ($COURSE->id != SITEID and !empty($USER->realuser)) {
1640         if ($USER->loginascontext->contextlevel == CONTEXT_COURSE) {
1641             if ($USER->loginascontext->instanceid != $COURSE->id) {
1642                 print_error('loginasonecourse', '', $CFG->wwwroot.'/course/view.php?id='.$USER->loginascontext->instanceid);
1643             }
1644         }
1645     }
1646
1647
1648 /// check whether the user should be changing password (but only if it is REALLY them)
1649     $userauth = get_auth_plugin($USER->auth);
1650     if (get_user_preferences('auth_forcepasswordchange') && empty($USER->realuser)) {
1651         if ($userauth->can_change_password()) {
1652             $SESSION->wantsurl = $FULLME;
1653             if ($changeurl = $userauth->change_password_url()) {
1654                 //use plugin custom url
1655                 redirect($changeurl);
1656             } else {
1657                 //use moodle internal method
1658                 if (empty($CFG->loginhttps)) {
1659                     redirect($CFG->wwwroot .'/login/change_password.php');
1660                 } else {
1661                     $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1662                     redirect($wwwroot .'/login/change_password.php');
1663                 }
1664             }
1665         } else {
1666             error(get_string('nopasswordchangeforced', 'auth'));
1667         }
1668     }
1669
1670 /// Check that the user account is properly set up
1671     if (user_not_fully_set_up($USER)) {
1672         $SESSION->wantsurl = $FULLME;
1673         redirect($CFG->wwwroot .'/user/edit.php?id='. $USER->id .'&amp;course='. SITEID);
1674     }
1675
1676 /// Make sure current IP matches the one for this session (if required)
1677     if (!empty($CFG->tracksessionip)) {
1678         if ($USER->sessionIP != md5(getremoteaddr())) {
1679             error(get_string('sessionipnomatch', 'error'));
1680         }
1681     }
1682
1683 /// Make sure the USER has a sesskey set up.  Used for checking script parameters.
1684     sesskey();
1685
1686     // Check that the user has agreed to a site policy if there is one
1687     if (!empty($CFG->sitepolicy)) {
1688         if (!$USER->policyagreed) {
1689             $SESSION->wantsurl = $FULLME;
1690             redirect($CFG->wwwroot .'/user/policy.php');
1691         }
1692     }
1693
1694 /// If the site is currently under maintenance, then print a message
1695     if (!has_capability('moodle/site:config',get_context_instance(CONTEXT_SYSTEM))) {
1696         if (file_exists($CFG->dataroot.'/'.SITEID.'/maintenance.html')) {
1697             print_maintenance_message();
1698             exit;
1699         }
1700     }
1701
1702 /// groupmembersonly access control
1703     if (!empty($CFG->enablegroupings) and $cm and $cm->groupmembersonly and !has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
1704         if (isguestuser() or !groups_has_membership($cm)) {
1705             error(get_string('groupmembersonlyerror', 'group'), $CFG->wwwroot.'/course/view.php?id='.$cm->course);
1706         }
1707     }
1708
1709     if ($COURSE->id == SITEID) {
1710 /// We can eliminate hidden site activities straight away
1711         if (!empty($cm) && !$cm->visible and !has_capability('moodle/course:viewhiddenactivities',
1712                                                       get_context_instance(CONTEXT_SYSTEM))) {
1713             redirect($CFG->wwwroot, get_string('activityiscurrentlyhidden'));
1714         }
1715         return;
1716
1717     } else {
1718 /// Check if the user can be in a particular course
1719         if (!$context = get_context_instance(CONTEXT_COURSE, $COURSE->id)) {
1720             print_error('nocontext');
1721         }
1722
1723         if (empty($USER->switchrole[$context->id]) &&
1724             !($COURSE->visible && course_parent_visible($COURSE)) &&
1725                !has_capability('moodle/course:viewhiddencourses', get_context_instance(CONTEXT_COURSE, $COURSE->id)) ){
1726             print_header_simple();
1727             notice(get_string('coursehidden'), $CFG->wwwroot .'/');
1728         }
1729
1730     /// Non-guests who don't currently have access, check if they can be allowed in as a guest
1731
1732         if ($USER->username != 'guest' and !has_capability('moodle/course:view', $context)) {
1733             if ($COURSE->guest == 1) {
1734                  // Temporarily assign them guest role for this context, if it fails later user is asked to enrol
1735                  has_capability('clearcache');   // Must clear cache
1736                  $guestcaps = get_role_context_caps($CFG->guestroleid, $context);
1737                  $USER->capabilities = merge_role_caps($USER->capabilities, $guestcaps);
1738             }
1739         }
1740
1741     /// If the user is a guest then treat them according to the course policy about guests
1742
1743         if (has_capability('moodle/legacy:guest', $context, NULL, false)) {
1744             switch ($COURSE->guest) {    /// Check course policy about guest access
1745
1746                 case 1:    /// Guests always allowed
1747                     if (!has_capability('moodle/course:view', $context)) {    // Prohibited by capability
1748                         print_header_simple();
1749                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1750                     }
1751                     if (!empty($cm) and !$cm->visible) { // Not allowed to see module, send to course page
1752                         redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course,
1753                                  get_string('activityiscurrentlyhidden'));
1754                     }
1755
1756                     return;   // User is allowed to see this course
1757
1758                     break;
1759
1760                 case 2:    /// Guests allowed with key
1761                     if (!empty($USER->enrolkey[$COURSE->id])) {   // Set by enrol/manual/enrol.php
1762                         return true;
1763                     }
1764                     //  otherwise drop through to logic below (--> enrol.php)
1765                     break;
1766
1767                 default:    /// Guests not allowed
1768                     $strloggedinasguest = get_string('loggedinasguest');
1769                     print_header_simple('', '',
1770                             build_navigation(array(array('name' => $strloggedinasguest, 'link' => null, 'type' => 'misc'))));
1771                     if (empty($USER->switchrole[$context->id])) {  // Normal guest
1772                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1773                     } else {
1774                         notify(get_string('guestsnotallowed', '', format_string($COURSE->fullname)));
1775                         echo '<div class="notifyproblem">'.switchroles_form($COURSE->id).'</div>';
1776                         print_footer($COURSE);
1777                         exit;
1778                     }
1779                     break;
1780             }
1781
1782     /// For non-guests, check if they have course view access
1783
1784         } else if (has_capability('moodle/course:view', $context)) {
1785             if (!empty($USER->realuser)) {   // Make sure the REAL person can also access this course
1786                 if (!has_capability('moodle/course:view', $context, $USER->realuser)) {
1787                     print_header_simple();
1788                     notice(get_string('studentnotallowed', '', fullname($USER, true)), $CFG->wwwroot .'/');
1789                 }
1790             }
1791
1792         /// Make sure they can read this activity too, if specified
1793
1794             if (!empty($cm) and !$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $context)) {
1795                 redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course, get_string('activityiscurrentlyhidden'));
1796             }
1797             return;   // User is allowed to see this course
1798
1799         }
1800
1801
1802     /// Currently not enrolled in the course, so see if they want to enrol
1803         $SESSION->wantsurl = $FULLME;
1804         redirect($CFG->wwwroot .'/course/enrol.php?id='. $COURSE->id);
1805         die;
1806     }
1807 }
1808
1809
1810
1811 /**
1812  * This function just makes sure a user is logged out.
1813  *
1814  * @uses $CFG
1815  * @uses $USER
1816  */
1817 function require_logout() {
1818
1819     global $USER, $CFG, $SESSION;
1820
1821     if (isloggedin()) {
1822         add_to_log(SITEID, "user", "logout", "view.php?id=$USER->id&course=".SITEID, $USER->id, 0, $USER->id);
1823
1824         $authsequence = get_enabled_auth_plugins(); // auths, in sequence
1825         foreach($authsequence as $authname) {
1826             $authplugin = get_auth_plugin($authname);
1827             $authplugin->prelogout_hook();
1828         }
1829     }
1830
1831     if (ini_get_bool("register_globals") and check_php_version("4.3.0")) {
1832         // This method is just to try to avoid silly warnings from PHP 4.3.0
1833         session_unregister("USER");
1834         session_unregister("SESSION");
1835     }
1836
1837     // Initialize variable to pass-by-reference to headers_sent(&$file, &$line)
1838     $file = $line = null;
1839     if (headers_sent($file, $line)) {
1840         error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
1841         error_log('Headers were already sent in file: '.$file.' on line '.$line);
1842     } else {
1843         setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
1844     }
1845
1846     unset($_SESSION['USER']);
1847     unset($_SESSION['SESSION']);
1848
1849     unset($SESSION);
1850     unset($USER);
1851
1852 }
1853
1854 /**
1855  * This is a weaker version of {@link require_login()} which only requires login
1856  * when called from within a course rather than the site page, unless
1857  * the forcelogin option is turned on.
1858  *
1859  * @uses $CFG
1860  * @param mixed $courseorid The course object or id in question
1861  * @param bool $autologinguest Allow autologin guests if that is wanted
1862  * @param object $cm Course activity module if known
1863  */
1864 function require_course_login($courseorid, $autologinguest=true, $cm=null) {
1865     global $CFG;
1866     if (!empty($CFG->forcelogin)) {
1867         // login required for both SITE and courses
1868         require_login($courseorid, $autologinguest, $cm);
1869
1870     } else if (!empty($cm) and !$cm->visible) {
1871         // always login for hidden activities
1872         require_login($courseorid, $autologinguest, $cm);
1873
1874     } else if ((is_object($courseorid) and $courseorid->id == SITEID)
1875           or (!is_object($courseorid) and $courseorid == SITEID)) {
1876         //login for SITE not required
1877         return;
1878
1879     } else {
1880         // course login always required
1881         require_login($courseorid, $autologinguest, $cm);
1882     }
1883 }
1884
1885 /**
1886  * Require key login. Function terminates with error if key not found or incorrect.
1887  * @param string $script unique script identifier
1888  * @param int $instance optional instance id
1889  */
1890 function require_user_key_login($script, $instance=null) {
1891     global $nomoodlecookie, $USER, $SESSION;
1892
1893     if (empty($nomoodlecookie)) {
1894         error('Incorrect use of require_key_login() - session cookies must be disabled!');
1895     }
1896
1897 /// extra safety
1898     @session_write_close();
1899
1900     $keyvalue = required_param('key', PARAM_ALPHANUM);
1901
1902     if (!$key = get_record('user_private_key', 'script', $script, 'value', $keyvalue, 'instance', $instance)) {
1903         error('Incorrect key');
1904     }
1905
1906     if (!empty($key->validuntil) and $key->validuntil < time()) {
1907         error('Expired key');
1908     }
1909
1910     if ($key->iprestriction) {
1911         $remoteaddr = getremoteaddr();
1912         if ($remoteaddr == '' or !address_in_subnet($remoteaddr, $key->iprestriction)) {
1913             error('Client IP address mismatch');
1914         }
1915     }
1916
1917     if (!$user = get_record('user', 'id', $key->userid)) {
1918         error('Incorrect user record');
1919     }
1920
1921 /// emulate normal session
1922     $SESSION = new object();
1923     $USER    = $user;
1924
1925 /// return isntance id - it might be empty
1926     return $key->instance;
1927 }
1928
1929 /**
1930  * Creates a new private user access key.
1931  * @param string $script unique target identifier
1932  * @param int $userid
1933  * @param instance $int optional instance id
1934  * @param string $iprestriction optional ip restricted access
1935  * @param timestamp $validuntil key valid only until given data
1936  * @return string access key value
1937  */
1938 function create_user_key($script, $userid, $instance=null, $iprestriction=null, $validuntil=null) {
1939     $key = new object();
1940     $key->script        = $script;
1941     $key->userid        = $userid;
1942     $key->instance      = $instance;
1943     $key->iprestriction = $iprestriction;
1944     $key->validuntil    = $validuntil;
1945     $key->timecreated   = time();
1946
1947     $key->value         = md5($userid.'_'.time().random_string(40)); // something long and unique
1948     while (record_exists('user_private_key', 'value', $key->value)) {
1949         // must be unique
1950         $key->value     = md5($userid.'_'.time().random_string(40));
1951     }
1952
1953     if (!insert_record('user_private_key', $key)) {
1954         error('Can not insert new key');
1955     }
1956
1957     return $key->value;
1958 }
1959
1960 /**
1961  * Modify the user table by setting the currently logged in user's
1962  * last login to now.
1963  *
1964  * @uses $USER
1965  * @return bool
1966  */
1967 function update_user_login_times() {
1968     global $USER;
1969
1970     $user = new object();
1971     $USER->lastlogin = $user->lastlogin = $USER->currentlogin;
1972     $USER->currentlogin = $user->lastaccess = $user->currentlogin = time();
1973
1974     $user->id = $USER->id;
1975
1976     return update_record('user', $user);
1977 }
1978
1979 /**
1980  * Determines if a user has completed setting up their account.
1981  *
1982  * @param user $user A {@link $USER} object to test for the existance of a valid name and email
1983  * @return bool
1984  */
1985 function user_not_fully_set_up($user) {
1986     return ($user->username != 'guest' and (empty($user->firstname) or empty($user->lastname) or empty($user->email) or over_bounce_threshold($user)));
1987 }
1988
1989 function over_bounce_threshold($user) {
1990
1991     global $CFG;
1992
1993     if (empty($CFG->handlebounces)) {
1994         return false;
1995     }
1996     // set sensible defaults
1997     if (empty($CFG->minbounces)) {
1998         $CFG->minbounces = 10;
1999     }
2000     if (empty($CFG->bounceratio)) {
2001         $CFG->bounceratio = .20;
2002     }
2003     $bouncecount = 0;
2004     $sendcount = 0;
2005     if ($bounce = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2006         $bouncecount = $bounce->value;
2007     }
2008     if ($send = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2009         $sendcount = $send->value;
2010     }
2011     return ($bouncecount >= $CFG->minbounces && $bouncecount/$sendcount >= $CFG->bounceratio);
2012 }
2013
2014 /**
2015  * @param $user - object containing an id
2016  * @param $reset - will reset the count to 0
2017  */
2018 function set_send_count($user,$reset=false) {
2019     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2020         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2021         update_record('user_preferences',$pref);
2022     }
2023     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2024         // make a new one
2025         $pref->name = 'email_send_count';
2026         $pref->value = 1;
2027         $pref->userid = $user->id;
2028         insert_record('user_preferences',$pref, false);
2029     }
2030 }
2031
2032 /**
2033 * @param $user - object containing an id
2034  * @param $reset - will reset the count to 0
2035  */
2036 function set_bounce_count($user,$reset=false) {
2037     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2038         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2039         update_record('user_preferences',$pref);
2040     }
2041     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2042         // make a new one
2043         $pref->name = 'email_bounce_count';
2044         $pref->value = 1;
2045         $pref->userid = $user->id;
2046         insert_record('user_preferences',$pref, false);
2047     }
2048 }
2049
2050 /**
2051  * Keeps track of login attempts
2052  *
2053  * @uses $SESSION
2054  */
2055 function update_login_count() {
2056
2057     global $SESSION;
2058
2059     $max_logins = 10;
2060
2061     if (empty($SESSION->logincount)) {
2062         $SESSION->logincount = 1;
2063     } else {
2064         $SESSION->logincount++;
2065     }
2066
2067     if ($SESSION->logincount > $max_logins) {
2068         unset($SESSION->wantsurl);
2069         error(get_string('errortoomanylogins'));
2070     }
2071 }
2072
2073 /**
2074  * Resets login attempts
2075  *
2076  * @uses $SESSION
2077  */
2078 function reset_login_count() {
2079     global $SESSION;
2080
2081     $SESSION->logincount = 0;
2082 }
2083
2084 function sync_metacourses() {
2085
2086     global $CFG;
2087
2088     if (!$courses = get_records('course', 'metacourse', 1)) {
2089         return;
2090     }
2091
2092     foreach ($courses as $course) {
2093         sync_metacourse($course);
2094     }
2095 }
2096
2097 /**
2098  * Goes through all enrolment records for the courses inside the metacourse and sync with them.
2099  *
2100  * @param mixed $course the metacourse to synch. Either the course object itself, or the courseid.
2101  */
2102 function sync_metacourse($course) {
2103     global $CFG;
2104
2105     // Check the course is valid.
2106     if (!is_object($course)) {
2107         if (!$course = get_record('course', 'id', $course)) {
2108             return false; // invalid course id
2109         }
2110     }
2111
2112     // Check that we actually have a metacourse.
2113     if (empty($course->metacourse)) {
2114         return false;
2115     }
2116
2117     // Get a list of roles that should not be synced.
2118     if (!empty($CFG->nonmetacoursesyncroleids)) {
2119         $roleexclusions = 'ra.roleid NOT IN (' . $CFG->nonmetacoursesyncroleids . ') AND';
2120     } else {
2121         $roleexclusions = '';
2122     }
2123
2124     // Get the context of the metacourse.
2125     $context = get_context_instance(CONTEXT_COURSE, $course->id); // SITEID can not be a metacourse
2126
2127     // We do not ever want to unassign the list of metacourse manager, so get a list of them.
2128     if ($users = get_users_by_capability($context, 'moodle/course:managemetacourse')) {
2129         $managers = array_keys($users);
2130     } else {
2131         $managers = array();
2132     }
2133
2134     // Get assignments of a user to a role that exist in a child course, but
2135     // not in the meta coure. That is, get a list of the assignments that need to be made.
2136     if (!$assignments = get_records_sql("
2137             SELECT
2138                 ra.id, ra.roleid, ra.userid
2139             FROM
2140                 {$CFG->prefix}role_assignments ra,
2141                 {$CFG->prefix}context con,
2142                 {$CFG->prefix}course_meta cm
2143             WHERE
2144                 ra.contextid = con.id AND
2145                 con.contextlevel = " . CONTEXT_COURSE . " AND
2146                 con.instanceid = cm.child_course AND
2147                 cm.parent_course = {$course->id} AND
2148                 $roleexclusions
2149                 NOT EXISTS (
2150                     SELECT 1 FROM
2151                         {$CFG->prefix}role_assignments ra2
2152                     WHERE
2153                         ra2.userid = ra.userid AND
2154                         ra2.roleid = ra.roleid AND
2155                         ra2.contextid = {$context->id}
2156                 )
2157     ")) {
2158         $assignments = array();
2159     }
2160
2161     // Get assignments of a user to a role that exist in the meta course, but
2162     // not in any child courses. That is, get a list of the unassignments that need to be made.
2163     if (!$unassignments = get_records_sql("
2164             SELECT
2165                 ra.id, ra.roleid, ra.userid
2166             FROM
2167                 {$CFG->prefix}role_assignments ra
2168             WHERE
2169                 ra.contextid = {$context->id} AND
2170                 $roleexclusions
2171                 NOT EXISTS (
2172                     SELECT 1 FROM
2173                         {$CFG->prefix}role_assignments ra2,
2174                         {$CFG->prefix}context con2,
2175                         {$CFG->prefix}course_meta cm
2176                     WHERE
2177                         ra2.userid = ra.userid AND
2178                         ra2.roleid = ra.roleid AND
2179                         ra2.contextid = con2.id AND
2180                         con2.contextlevel = " . CONTEXT_COURSE . " AND
2181                         con2.instanceid = cm.child_course AND
2182                         cm.parent_course = {$course->id}
2183                 )
2184     ")) {
2185         $unassignments = array();
2186     }
2187
2188     $success = true;
2189
2190     // Make the unassignments, if they are not managers.
2191     foreach ($unassignments as $unassignment) {
2192         if (!in_array($unassignment->userid, $managers)) {
2193             $success = role_unassign($unassignment->roleid, $unassignment->userid, 0, $context->id) && $success;
2194         }
2195     }
2196
2197     // Make the assignments.
2198     foreach ($assignments as $assignment) {
2199         $success = role_assign($assignment->roleid, $assignment->userid, 0, $context->id) && $success;
2200     }
2201
2202     return $success;
2203
2204 // TODO: finish timeend and timestart
2205 // maybe we could rely on cron job to do the cleaning from time to time
2206 }
2207
2208 /**
2209  * Adds a record to the metacourse table and calls sync_metacoures
2210  */
2211 function add_to_metacourse ($metacourseid, $courseid) {
2212
2213     if (!$metacourse = get_record("course","id",$metacourseid)) {
2214         return false;
2215     }
2216
2217     if (!$course = get_record("course","id",$courseid)) {
2218         return false;
2219     }
2220
2221     if (!$record = get_record("course_meta","parent_course",$metacourseid,"child_course",$courseid)) {
2222         $rec = new object();
2223         $rec->parent_course = $metacourseid;
2224         $rec->child_course = $courseid;
2225         if (!insert_record('course_meta',$rec)) {
2226             return false;
2227         }
2228         return sync_metacourse($metacourseid);
2229     }
2230     return true;
2231
2232 }
2233
2234 /**
2235  * Removes the record from the metacourse table and calls sync_metacourse
2236  */
2237 function remove_from_metacourse($metacourseid, $courseid) {
2238
2239     if (delete_records('course_meta','parent_course',$metacourseid,'child_course',$courseid)) {
2240         return sync_metacourse($metacourseid);
2241     }
2242     return false;
2243 }
2244
2245
2246 /**
2247  * Determines if a user is currently logged in
2248  *
2249  * @uses $USER
2250  * @return bool
2251  */
2252 function isloggedin() {
2253     global $USER;
2254
2255     return (!empty($USER->id));
2256 }
2257
2258 /**
2259  * Determines if a user is logged in as real guest user with username 'guest'.
2260  * This function is similar to original isguest() in 1.6 and earlier.
2261  * Current isguest() is deprecated - do not use it anymore.
2262  *
2263  * @param $user mixed user object or id, $USER if not specified
2264  * @return bool true if user is the real guest user, false if not logged in or other user
2265  */
2266 function isguestuser($user=NULL) {
2267     global $USER;
2268     if ($user === NULL) {
2269         $user = $USER;
2270     } else if (is_numeric($user)) {
2271         $user = get_record('user', 'id', $user, '', '', '', '', 'id, username');
2272     }
2273
2274     if (empty($user->id)) {
2275         return false; // not logged in, can not be guest
2276     }
2277
2278     return ($user->username == 'guest');
2279 }
2280
2281 /**
2282  * Determines if the currently logged in user is in editing mode.
2283  * Note: originally this function had $userid parameter - it was not usable anyway
2284  *
2285  * @uses $USER
2286  * @param int $courseid The id of the course being tested
2287  * @return bool
2288  */
2289 function isediting($courseid) {
2290     global $USER;
2291
2292     if (empty($USER->editing)) {
2293         return false;
2294
2295     } else {
2296         return editcourseallowed($courseid);
2297     }
2298 }
2299
2300 /**
2301  * Verifies if user allowed to edit something in the course page.
2302  * @param int $courseid The id of the course being tested
2303  * @return bool
2304  */
2305 function editcourseallowed($courseid) {
2306     global $USER;
2307
2308     // cache the result per course, it is automatically reset when using switchrole or loginas
2309     if (!array_key_exists('courseeditallowed', $USER)) {
2310         $USER->courseeditallowed = array();
2311     }
2312
2313     if (!array_key_exists($courseid, $USER->courseeditallowed)) {
2314         $USER->courseeditallowed[$courseid] = has_capability_including_child_contexts(get_context_instance(CONTEXT_COURSE, $courseid),
2315                                             array('moodle/site:manageblocks', 'moodle/course:manageactivities'));
2316     }
2317
2318     return $USER->courseeditallowed[$courseid];
2319 }
2320
2321 /**
2322  * Determines if the logged in user is currently moving an activity
2323  *
2324  * @uses $USER
2325  * @param int $courseid The id of the course being tested
2326  * @return bool
2327  */
2328 function ismoving($courseid) {
2329     global $USER;
2330
2331     if (!empty($USER->activitycopy)) {
2332         return ($USER->activitycopycourse == $courseid);
2333     }
2334     return false;
2335 }
2336
2337 /**
2338  * Given an object containing firstname and lastname
2339  * values, this function returns a string with the
2340  * full name of the person.
2341  * The result may depend on system settings
2342  * or language.  'override' will force both names
2343  * to be used even if system settings specify one.
2344  *
2345  * @uses $CFG
2346  * @uses $SESSION
2347  * @param object $user A {@link $USER} object to get full name of
2348  * @param bool $override If true then the name will be first name followed by last name rather than adhering to fullnamedisplay setting.
2349  */
2350 function fullname($user, $override=false) {
2351
2352     global $CFG, $SESSION;
2353
2354     if (!isset($user->firstname) and !isset($user->lastname)) {
2355         return '';
2356     }
2357
2358     if (!$override) {
2359         if (!empty($CFG->forcefirstname)) {
2360             $user->firstname = $CFG->forcefirstname;
2361         }
2362         if (!empty($CFG->forcelastname)) {
2363             $user->lastname = $CFG->forcelastname;
2364         }
2365     }
2366
2367     if (!empty($SESSION->fullnamedisplay)) {
2368         $CFG->fullnamedisplay = $SESSION->fullnamedisplay;
2369     }
2370
2371     if ($CFG->fullnamedisplay == 'firstname lastname') {
2372         return $user->firstname .' '. $user->lastname;
2373
2374     } else if ($CFG->fullnamedisplay == 'lastname firstname') {
2375         return $user->lastname .' '. $user->firstname;
2376
2377     } else if ($CFG->fullnamedisplay == 'firstname') {
2378         if ($override) {
2379             return get_string('fullnamedisplay', '', $user);
2380         } else {
2381             return $user->firstname;
2382         }
2383     }
2384
2385     return get_string('fullnamedisplay', '', $user);
2386 }
2387
2388 /**
2389  * Sets a moodle cookie with an encrypted string
2390  *
2391  * @uses $CFG
2392  * @uses DAYSECS
2393  * @uses HOURSECS
2394  * @param string $thing The string to encrypt and place in a cookie
2395  */
2396 function set_moodle_cookie($thing) {
2397     global $CFG;
2398
2399     if ($thing == 'guest') {  // Ignore guest account
2400         return;
2401     }
2402
2403     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2404
2405     $days = 60;
2406     $seconds = DAYSECS*$days;
2407
2408     setCookie($cookiename, '', time() - HOURSECS, '/');
2409     setCookie($cookiename, rc4encrypt($thing), time()+$seconds, '/');
2410 }
2411
2412 /**
2413  * Gets a moodle cookie with an encrypted string
2414  *
2415  * @uses $CFG
2416  * @return string
2417  */
2418 function get_moodle_cookie() {
2419     global $CFG;
2420
2421     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2422
2423     if (empty($_COOKIE[$cookiename])) {
2424         return '';
2425     } else {
2426         $thing = rc4decrypt($_COOKIE[$cookiename]);
2427         return ($thing == 'guest') ? '': $thing;  // Ignore guest account
2428     }
2429 }
2430
2431 /**
2432  * Returns whether a given authentication plugin exists.
2433  *
2434  * @uses $CFG
2435  * @param string $auth Form of authentication to check for. Defaults to the
2436  *        global setting in {@link $CFG}.
2437  * @return boolean Whether the plugin is available.
2438  */
2439 function exists_auth_plugin($auth) {
2440     global $CFG;
2441
2442     if (file_exists("{$CFG->dirroot}/auth/$auth/auth.php")) {
2443         return is_readable("{$CFG->dirroot}/auth/$auth/auth.php");
2444     }
2445     return false;
2446 }
2447
2448 /**
2449  * Checks if a given plugin is in the list of enabled authentication plugins.
2450  *
2451  * @param string $auth Authentication plugin.
2452  * @return boolean Whether the plugin is enabled.
2453  */
2454 function is_enabled_auth($auth) {
2455     if (empty($auth)) {
2456         return false;
2457     }
2458
2459     $enabled = get_enabled_auth_plugins();
2460
2461     return in_array($auth, $enabled);
2462 }
2463
2464 /**
2465  * Returns an authentication plugin instance.
2466  *
2467  * @uses $CFG
2468  * @param string $auth name of authentication plugin
2469  * @return object An instance of the required authentication plugin.
2470  */
2471 function get_auth_plugin($auth) {
2472     global $CFG;
2473
2474     // check the plugin exists first
2475     if (! exists_auth_plugin($auth)) {
2476         error("Authentication plugin '$auth' not found.");
2477     }
2478
2479     // return auth plugin instance
2480     require_once "{$CFG->dirroot}/auth/$auth/auth.php";
2481     $class = "auth_plugin_$auth";
2482     return new $class;
2483 }
2484
2485 /**
2486  * Returns array of active auth plugins.
2487  *
2488  * @param bool $fix fix $CFG->auth if needed
2489  * @return array
2490  */
2491 function get_enabled_auth_plugins($fix=false) {
2492     global $CFG;
2493
2494     $default = array('manual', 'nologin');
2495
2496     if (empty($CFG->auth)) {
2497         $auths = array();
2498     } else {
2499         $auths = explode(',', $CFG->auth);
2500     }
2501
2502     if ($fix) {
2503         $auths = array_unique($auths);
2504         foreach($auths as $k=>$authname) {
2505             if (!exists_auth_plugin($authname) or in_array($authname, $default)) {
2506                 unset($auths[$k]);
2507             }
2508         }
2509         $newconfig = implode(',', $auths);
2510         if (!isset($CFG->auth) or $newconfig != $CFG->auth) {
2511             set_config('auth', $newconfig);
2512         }
2513     }
2514
2515     return (array_merge($default, $auths));
2516 }
2517
2518 /**
2519  * Returns true if an internal authentication method is being used.
2520  * if method not specified then, global default is assumed
2521  *
2522  * @uses $CFG
2523  * @param string $auth Form of authentication required
2524  * @return bool
2525  */
2526 function is_internal_auth($auth) {
2527     $authplugin = get_auth_plugin($auth); // throws error if bad $auth
2528     return $authplugin->is_internal();
2529 }
2530
2531 /**
2532  * Returns an array of user fields
2533  *
2534  * @uses $CFG
2535  * @uses $db
2536  * @return array User field/column names
2537  */
2538 function get_user_fieldnames() {
2539
2540     global $CFG, $db;
2541
2542     $fieldarray = $db->MetaColumnNames($CFG->prefix.'user');
2543     unset($fieldarray['ID']);
2544
2545     return $fieldarray;
2546 }
2547
2548 /**
2549  * Creates the default "guest" user. Used both from
2550  * admin/index.php and login/index.php
2551  * @return mixed user object created or boolean false if the creation has failed
2552  */
2553 function create_guest_record() {
2554
2555     global $CFG;
2556
2557     $guest->auth        = 'manual';
2558     $guest->username    = 'guest';
2559     $guest->password    = hash_internal_user_password('guest');
2560     $guest->firstname   = addslashes(get_string('guestuser'));
2561     $guest->lastname    = ' ';
2562     $guest->email       = 'root@localhost';
2563     $guest->description = addslashes(get_string('guestuserinfo'));
2564     $guest->mnethostid  = $CFG->mnet_localhost_id;
2565     $guest->confirmed   = 1;
2566     $guest->lang        = $CFG->lang;
2567     $guest->timemodified= time();
2568
2569     if (! $guest->id = insert_record("user", $guest)) {
2570         return false;
2571     }
2572
2573     return $guest;
2574 }
2575
2576 /**
2577  * Creates a bare-bones user record
2578  *
2579  * @uses $CFG
2580  * @param string $username New user's username to add to record
2581  * @param string $password New user's password to add to record
2582  * @param string $auth Form of authentication required
2583  * @return object A {@link $USER} object
2584  * @todo Outline auth types and provide code example
2585  */
2586 function create_user_record($username, $password, $auth='manual') {
2587     global $CFG;
2588
2589     //just in case check text case
2590     $username = trim(moodle_strtolower($username));
2591
2592     $authplugin = get_auth_plugin($auth);
2593
2594     if ($newinfo = $authplugin->get_userinfo($username)) {
2595         $newinfo = truncate_userinfo($newinfo);
2596         foreach ($newinfo as $key => $value){
2597             $newuser->$key = addslashes($value);
2598         }
2599     }
2600
2601     if (!empty($newuser->email)) {
2602         if (email_is_not_allowed($newuser->email)) {
2603             unset($newuser->email);
2604         }
2605     }
2606
2607     $newuser->auth = $auth;
2608     $newuser->username = $username;
2609
2610     // fix for MDL-8480
2611     // user CFG lang for user if $newuser->lang is empty
2612     // or $user->lang is not an installed language
2613     $sitelangs = array_keys(get_list_of_languages());
2614     if (empty($newuser->lang) || !in_array($newuser->lang, $sitelangs)) {
2615         $newuser -> lang = $CFG->lang;
2616     }
2617     $newuser->confirmed = 1;
2618     $newuser->lastip = getremoteaddr();
2619     $newuser->timemodified = time();
2620     $newuser->mnethostid = $CFG->mnet_localhost_id;
2621
2622     if (insert_record('user', $newuser)) {
2623         $user = get_complete_user_data('username', $newuser->username);
2624         if(!empty($CFG->{'auth_'.$newuser->auth.'_forcechangepassword'})){
2625             set_user_preference('auth_forcepasswordchange', 1, $user->id);
2626         }
2627         update_internal_user_password($user, $password);
2628         return $user;
2629     }
2630     return false;
2631 }
2632
2633 /**
2634  * Will update a local user record from an external source
2635  *
2636  * @uses $CFG
2637  * @param string $username New user's username to add to record
2638  * @return user A {@link $USER} object
2639  */
2640 function update_user_record($username, $authplugin) {
2641     $username = trim(moodle_strtolower($username)); /// just in case check text case
2642
2643     $oldinfo = get_record('user', 'username', $username, '','','','', 'username, auth');
2644     $userauth = get_auth_plugin($oldinfo->auth);
2645
2646     if ($newinfo = $userauth->get_userinfo($username)) {
2647         $newinfo = truncate_userinfo($newinfo);
2648         foreach ($newinfo as $key => $value){
2649             $confkey = 'field_updatelocal_' . $key;
2650             if (!empty($userauth->config->$confkey) and $userauth->config->$confkey === 'onlogin') {
2651                 $value = addslashes(stripslashes($value));   // Just in case
2652                 set_field('user', $key, $value, 'username', $username)
2653                     or error_log("Error updating $key for $username");
2654             }
2655         }
2656     }
2657
2658     return get_complete_user_data('username', $username);
2659 }
2660
2661 function truncate_userinfo($info) {
2662 /// will truncate userinfo as it comes from auth_get_userinfo (from external auth)
2663 /// which may have large fields
2664
2665     // define the limits
2666     $limit = array(
2667                     'username'    => 100,
2668                     'idnumber'    =>  64,
2669                     'firstname'   => 100,
2670                     'lastname'    => 100,
2671                     'email'       => 100,
2672                     'icq'         =>  15,
2673                     'phone1'      =>  20,
2674                     'phone2'      =>  20,
2675                     'institution' =>  40,
2676                     'department'  =>  30,
2677                     'address'     =>  70,
2678                     'city'        =>  20,
2679                     'country'     =>   2,
2680                     'url'         => 255,
2681                     );
2682
2683     // apply where needed
2684     foreach (array_keys($info) as $key) {
2685         if (!empty($limit[$key])) {
2686             $info[$key] = trim(substr($info[$key],0, $limit[$key]));
2687         }
2688     }
2689
2690     return $info;
2691 }
2692
2693 /**
2694  * Marks user deleted in internal user database and notifies the auth plugin.
2695  * Also unenrols user from all roles and does other cleanup.
2696  * @param object $user       Userobject before delete    (without system magic quotes)
2697  * @return boolean success
2698  */
2699 function delete_user($user) {
2700     global $CFG;
2701     require_once($CFG->libdir.'/grouplib.php');
2702
2703     begin_sql();
2704
2705     // delete all grades - backup is kept in grade_grades_history table
2706     if ($grades = grade_grade::fetch_all(array('userid'=>$user->id))) {
2707         foreach ($grades as $grade) {
2708             $grade->delete('userdelete');
2709         }
2710     }
2711
2712     // remove from all groups
2713     delete_records('groups_members', 'userid', $user->id);
2714
2715     // unenrol from all roles in all contexts
2716     role_unassign(0, $user->id); // this might be slow but it is really needed - modules might do some extra cleanup!
2717
2718     // now do a final accesslib cleanup - removes all role assingments in user context and context itself
2719     delete_context(CONTEXT_USER, $user->id);
2720
2721     // mark internal user record as "deleted"
2722     $updateuser = new object();
2723     $updateuser->id           = $user->id;
2724     $updateuser->deleted      = 1;
2725     $updateuser->username     = addslashes("$user->email.".time());  // Remember it just in case
2726     $updateuser->email        = '';               // Clear this field to free it up
2727     $updateuser->idnumber     = '';               // Clear this field to free it up
2728     $updateuser->timemodified = time();
2729
2730     if (update_record('user', $updateuser)) {
2731         commit_sql();
2732         // notify auth plugin - do not block the delete even when plugin fails
2733         $authplugin = get_auth_plugin($user->auth);
2734         $authplugin->user_delete($user);
2735         return true;
2736
2737     } else {
2738         rollback_sql();
2739         return false;
2740     }
2741 }
2742
2743 /**
2744  * Retrieve the guest user object
2745  *
2746  * @uses $CFG
2747  * @return user A {@link $USER} object
2748  */
2749 function guest_user() {
2750     global $CFG;
2751
2752     if ($newuser = get_record('user', 'username', 'guest', 'mnethostid',  $CFG->mnet_localhost_id)) {
2753         $newuser->confirmed = 1;
2754         $newuser->lang = $CFG->lang;
2755         $newuser->lastip = getremoteaddr();
2756     }
2757
2758     return $newuser;
2759 }
2760
2761 /**
2762  * Given a username and password, this function looks them
2763  * up using the currently selected authentication mechanism,
2764  * and if the authentication is successful, it returns a
2765  * valid $user object from the 'user' table.
2766  *
2767  * Uses auth_ functions from the currently active auth module
2768  *
2769  * @uses $CFG
2770  * @param string $username  User's username (with system magic quotes)
2771  * @param string $password  User's password (with system magic quotes)
2772  * @return user|flase A {@link $USER} object or false if error
2773  */
2774 function authenticate_user_login($username, $password) {
2775
2776     global $CFG;
2777
2778     $authsenabled = get_enabled_auth_plugins();
2779
2780     if ($user = get_complete_user_data('username', $username)) {
2781         $auth = empty($user->auth) ? 'manual' : $user->auth;  // use manual if auth not set
2782         if ($auth=='nologin' or !is_enabled_auth($auth)) {
2783             add_to_log(0, 'login', 'error', 'index.php', $username);
2784             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Disabled Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2785             return false;
2786         }
2787         if (!empty($user->deleted)) {
2788             add_to_log(0, 'login', 'error', 'index.php', $username);
2789             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Deleted Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2790             return false;
2791         }
2792         $auths = array($auth);
2793
2794     } else {
2795         $auths = $authsenabled;
2796         $user = new object();
2797         $user->id = 0;     // User does not exist
2798     }
2799
2800     foreach ($auths as $auth) {
2801         $authplugin = get_auth_plugin($auth);
2802
2803         // on auth fail fall through to the next plugin
2804         if (!$authplugin->user_login($username, $password)) {
2805             continue;
2806         }
2807
2808         // successful authentication
2809         if ($user->id) {                          // User already exists in database
2810             if (empty($user->auth)) {             // For some reason auth isn't set yet
2811                 set_field('user', 'auth', $auth, 'username', $username);
2812                 $user->auth = $auth;
2813             }
2814
2815             update_internal_user_password($user, $password); // just in case salt or encoding were changed (magic quotes too one day)
2816
2817             if (!$authplugin->is_internal()) {            // update user record from external DB
2818                 $user = update_user_record($username, get_auth_plugin($user->auth));
2819             }
2820         } else {
2821             // if user not found, create him
2822             $user = create_user_record($username, $password, $auth);
2823         }
2824
2825         $authplugin->sync_roles($user);
2826
2827         foreach ($authsenabled as $hau) {
2828             $hauth = get_auth_plugin($hau);
2829             $hauth->user_authenticated_hook($user, $username, $password);
2830         }
2831
2832     /// Log in to a second system if necessary
2833     /// NOTICE: /sso/ will be moved to auth and deprecated soon; use user_authenticated_hook() instead
2834         if (!empty($CFG->sso)) {
2835             include_once($CFG->dirroot .'/sso/'. $CFG->sso .'/lib.php');
2836             if (function_exists('sso_user_login')) {
2837                 if (!sso_user_login($username, $password)) {   // Perform the signon process
2838                     notify('Second sign-on failed');
2839                 }
2840             }
2841         }
2842
2843         return $user;
2844
2845     }
2846
2847     // failed if all the plugins have failed
2848     add_to_log(0, 'login', 'error', 'index.php', $username);
2849     error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Failed Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2850     return false;
2851 }
2852
2853 /**
2854  * Compare password against hash stored in internal user table.
2855  * If necessary it also updates the stored hash to new format.
2856  *
2857  * @param object user
2858  * @param string plain text password
2859  * @return bool is password valid?
2860  */
2861 function validate_internal_user_password(&$user, $password) {
2862     global $CFG;
2863
2864     if (!isset($CFG->passwordsaltmain)) {
2865         $CFG->passwordsaltmain = '';
2866     }
2867
2868     $validated = false;
2869
2870     // get password original encoding in case it was not updated to unicode yet
2871     $textlib = textlib_get_instance();
2872     $convpassword = $textlib->convert($password, 'utf-8', get_string('oldcharset'));
2873
2874     if ($user->password == md5($password.$CFG->passwordsaltmain) or $user->password == md5($password)
2875         or $user->password == md5($convpassword.$CFG->passwordsaltmain) or $user->password == md5($convpassword)) {
2876         $validated = true;
2877     } else {
2878         for ($i=1; $i<=20; $i++) { //20 alternative salts should be enough, right?
2879             $alt = 'passwordsaltalt'.$i;
2880             if (!empty($CFG->$alt)) {
2881                 if ($user->password == md5($password.$CFG->$alt) or $user->password == md5($convpassword.$CFG->$alt)) {
2882                     $validated = true;
2883                     break;
2884                 }
2885             }
2886         }
2887     }
2888
2889     if ($validated) {
2890         // force update of password hash using latest main password salt and encoding if needed
2891         update_internal_user_password($user, $password);
2892     }
2893
2894     return $validated;
2895 }
2896
2897 /**
2898  * Calculate hashed value from password using current hash mechanism.
2899  *
2900  * @param string password
2901  * @return string password hash
2902  */
2903 function hash_internal_user_password($password) {
2904     global $CFG;
2905
2906     if (isset($CFG->passwordsaltmain)) {
2907         return md5($password.$CFG->passwordsaltmain);
2908     } else {
2909         return md5($password);
2910     }
2911 }
2912
2913 /**
2914  * Update pssword hash in user object.
2915  *
2916  * @param object user
2917  * @param string plain text password
2918  * @param bool store changes also in db, default true
2919  * @return true if hash changed
2920  */
2921 function update_internal_user_password(&$user, $password) {
2922     global $CFG;
2923
2924     $authplugin = get_auth_plugin($user->auth);
2925     if (!empty($authplugin->config->preventpassindb)) {
2926         $hashedpassword = 'not cached';
2927     } else {
2928         $hashedpassword = hash_internal_user_password($password);
2929     }
2930
2931     return set_field('user', 'password',  $hashedpassword, 'id', $user->id);
2932 }
2933
2934 /**
2935  * Get a complete user record, which includes all the info
2936  * in the user record
2937  * Intended for setting as $USER session variable
2938  *
2939  * @uses $CFG
2940  * @uses SITEID
2941  * @param string $field The user field to be checked for a given value.
2942  * @param string $value The value to match for $field.
2943  * @return user A {@link $USER} object.
2944  */
2945 function get_complete_user_data($field, $value, $mnethostid=null) {
2946
2947     global $CFG;
2948
2949     if (!$field || !$value) {
2950         return false;
2951     }
2952
2953 /// Build the WHERE clause for an SQL query
2954
2955     $constraints = $field .' = \''. $value .'\' AND deleted <> \'1\'';
2956
2957     if (is_null($mnethostid)) {
2958         // if null, we restrict to local users
2959         // ** testing for local user can be done with
2960         //    mnethostid = $CFG->mnet_localhost_id
2961         //    or with
2962         //    auth != 'mnet'
2963         //    but the first one is FAST with our indexes
2964         $mnethostid = $CFG->mnet_localhost_id;
2965     }
2966     $mnethostid = (int)$mnethostid;
2967     $constraints .= ' AND mnethostid = \''.$mnethostid.'\'';
2968
2969 /// Get all the basic user data
2970
2971     if (! $user = get_record_select('user', $constraints)) {
2972         return false;
2973     }
2974
2975 /// Get various settings and preferences
2976
2977     if ($displays = get_records('course_display', 'userid', $user->id)) {
2978         foreach ($displays as $display) {
2979             $user->display[$display->course] = $display->display;
2980         }
2981     }
2982
2983     $user->preference = get_user_preferences(null, null, $user->id);
2984
2985     if ($lastaccesses = get_records('user_lastaccess', 'userid', $user->id)) {
2986         foreach ($lastaccesses as $lastaccess) {
2987             $user->lastcourseaccess[$lastaccess->courseid] = $lastaccess->timeaccess;
2988         }
2989     }
2990
2991     $sql = "SELECT g.id, g.courseid
2992               FROM {$CFG->prefix}groups g, {$CFG->prefix}groups_members gm
2993              WHERE gm.groupid=g.id AND gm.userid={$user->id}";
2994
2995     // this is a special hack to speedup calendar display
2996     $user->groupmember = array();
2997     if ($groups = get_records_sql($sql)) {
2998         foreach ($groups as $group) {
2999             if (!array_key_exists($group->courseid, $user->groupmember)) {
3000                 $user->groupmember[$group->courseid] = array();
3001             }
3002             $user->groupmember[$group->courseid][$group->id] = $group->id;
3003         }
3004     }
3005
3006 /// Rewrite some variables if necessary
3007     if (!empty($user->description)) {
3008         $user->description = true;   // No need to cart all of it around
3009     }
3010     if ($user->username == 'guest') {
3011         $user->lang       = $CFG->lang;               // Guest language always same as site
3012         $user->firstname  = get_string('guestuser');  // Name always in current language
3013         $user->lastname   = ' ';
3014     }
3015
3016     $user->sesskey  = random_string(10);
3017     $user->sessionIP = md5(getremoteaddr());   // Store the current IP in the session
3018
3019     return $user;
3020 }
3021
3022 /**
3023  * @uses $CFG
3024  * @param string $password the password to be checked agains the password policy
3025  * @param string $errmsg the error message to display when the password doesn't comply with the policy.
3026  * @return bool true if the password is valid according to the policy. false otherwise.
3027  */
3028 function check_password_policy($password, &$errmsg) {
3029     global $CFG;
3030
3031     if (empty($CFG->passwordpolicy)) {
3032         return true;
3033     }
3034
3035     $textlib = new textlib();
3036     $errmsg = '';
3037     if ($textlib->strlen($password) < $CFG->minpasswordlength) {
3038         $errmsg = get_string('errorminpasswordlength', 'auth', $CFG->minpasswordlength);
3039
3040     } else if (preg_match_all('/[[:digit:]]/u', $password, $matches) < $CFG->minpassworddigits) {
3041         $errmsg = get_string('errorminpassworddigits', 'auth', $CFG->minpassworddigits);
3042
3043     } else if (preg_match_all('/[[:lower:]]/u', $password, $matches) < $CFG->minpasswordlower) {
3044         $errmsg = get_string('errorminpasswordlower', 'auth', $CFG->minpasswordlower);
3045
3046     } else if (preg_match_all('/[[:upper:]]/u', $password, $matches) < $CFG->minpasswordupper) {
3047         $errmsg = get_string('errorminpasswordupper', 'auth', $CFG->minpasswordupper);
3048
3049     } else if (preg_match_all('/[^[:upper:][:lower:][:digit:]]/u', $password, $matches) < $CFG->minpasswordnonalphanum) {
3050         $errmsg = get_string('errorminpasswordnonalphanum', 'auth', $CFG->minpasswordnonalphanum);
3051
3052     } else if ($password == 'admin' or $password == 'password') {
3053         $errmsg = get_string('unsafepassword');
3054     }
3055
3056     if ($errmsg == '') {
3057         return true;
3058     } else {
3059         return false;
3060     }
3061 }
3062
3063
3064 /**
3065  * When logging in, this function is run to set certain preferences
3066  * for the current SESSION
3067  */
3068 function set_login_session_preferences() {
3069     global $SESSION, $CFG;
3070
3071     $SESSION->justloggedin = true;
3072
3073     unset($SESSION->lang);
3074
3075     // Restore the calendar filters, if saved
3076     if (intval(get_user_preferences('calendar_persistflt', 0))) {
3077         include_once($CFG->dirroot.'/calendar/lib.php');
3078         calendar_set_filters_status(get_user_preferences('calendav_savedflt', 0xff));
3079     }
3080 }
3081
3082
3083 /**
3084  * Delete a course, including all related data from the database,
3085  * and any associated files from the moodledata folder.
3086  *
3087  * @param int $courseid The id of the course to delete.
3088  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3089  * @return bool true if all the removals succeeded. false if there were any failures. If this
3090  *             method returns false, some of the removals will probably have succeeded, and others
3091  *             failed, but you have no way of knowing which.
3092  */
3093 function delete_course($courseid, $showfeedback = true) {
3094     global $CFG;
3095     require_once($CFG->libdir.'/gradelib.php');
3096     $result = true;
3097
3098     if (!remove_course_contents($courseid, $showfeedback)) {
3099         if ($showfeedback) {
3100             notify("An error occurred while deleting some of the course contents.");
3101         }
3102         $result = false;
3103     }
3104
3105     remove_course_grades($courseid, $showfeedback);
3106
3107     if (!delete_records("course", "id", $courseid)) {
3108         if ($showfeedback) {
3109             notify("An error occurred while deleting the main course record.");
3110         }
3111         $result = false;
3112     }
3113
3114     if (!delete_records('context', 'contextlevel', CONTEXT_COURSE, 'instanceid', $courseid)) {
3115         if ($showfeedback) {
3116             notify("An error occurred while deleting the main context record.");
3117         }
3118         $result = false;
3119     }
3120
3121     if (!fulldelete($CFG->dataroot.'/'.$courseid)) {
3122         if ($showfeedback) {
3123             notify("An error occurred while deleting the course files.");
3124         }
3125         $result = false;
3126     }
3127
3128     return $result;
3129 }
3130
3131 /**
3132  * Clear a course out completely, deleting all content
3133  * but don't delete the course itself
3134  *
3135  * @uses $CFG
3136  * @param int $courseid The id of the course that is being deleted
3137  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3138  * @return bool true if all the removals succeeded. false if there were any failures. If this
3139  *             method returns false, some of the removals will probably have succeeded, and others
3140  *             failed, but you have no way of knowing which.
3141  */
3142 function remove_course_contents($courseid, $showfeedback=true) {
3143
3144     global $CFG;
3145     include_once($CFG->libdir.'/questionlib.php');
3146
3147     $result = true;
3148
3149     if (! $course = get_record('course', 'id', $courseid)) {
3150         error('Course ID was incorrect (can\'t find it)');
3151     }
3152
3153     $strdeleted = get_string('deleted');
3154
3155 /// First delete every instance of every module
3156
3157     if ($allmods = get_records('modules') ) {
3158         foreach ($allmods as $mod) {
3159             $modname = $mod->name;
3160             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3161             $moddelete = $modname .'_delete_instance';       // Delete everything connected to an instance
3162             $moddeletecourse = $modname .'_delete_course';   // Delete other stray stuff (uncommon)
3163             $count=0;
3164             if (file_exists($modfile)) {
3165                 include_once($modfile);
3166                 if (function_exists($moddelete)) {
3167                     if ($instances = get_records($modname, 'course', $course->id)) {
3168                         foreach ($instances as $instance) {
3169                             if ($cm = get_coursemodule_from_instance($modname, $instance->id, $course->id)) {
3170                                 /// Delete activity context questions and question categories
3171                                 question_delete_activity($cm,  $showfeedback);
3172                                 delete_context(CONTEXT_MODULE, $cm->id);
3173                             }
3174                             if ($moddelete($instance->id)) {
3175                                 $count++;
3176
3177                             } else {
3178                                 notify('Could not delete '. $modname .' instance '. $instance->id .' ('. format_string($instance->name) .')');
3179                                 $result = false;
3180                             }
3181                         }
3182                     }
3183                 } else {
3184                     notify('Function '. $moddelete() .'doesn\'t exist!');
3185                     $result = false;
3186                 }
3187
3188                 if (function_exists($moddeletecourse)) {
3189                     $moddeletecourse($course, $showfeedback);
3190                 }
3191             }
3192             if ($showfeedback) {
3193                 notify($strdeleted .' '. $count .' x '. $modname);
3194             }
3195         }
3196     } else {
3197         error('No modules are installed!');
3198     }
3199
3200 /// Give local code a chance to delete its references to this course.
3201     require_once('locallib.php');
3202     notify_local_delete_course($courseid, $showfeedback);
3203
3204 /// Delete course blocks
3205
3206     if ($blocks = get_records_sql("SELECT *
3207                                    FROM {$CFG->prefix}block_instance
3208                                    WHERE pagetype = '".PAGE_COURSE_VIEW."'
3209                                    AND pageid = $course->id")) {
3210         if (delete_records('block_instance', 'pagetype', PAGE_COURSE_VIEW, 'pageid', $course->id)) {
3211             if ($showfeedback) {
3212                 notify($strdeleted .' block_instance');
3213             }
3214
3215             require_once($CFG->libdir.'/blocklib.php');
3216             foreach ($blocks as $block) {  /// Delete any associated contexts for this block
3217
3218                 // Block instances are rarely created. Since the block instance is gone from the above delete
3219                 // statement, calling delete_context() will generate a warning as get_context_instance could
3220                 // no longer create the context as the block is already gone.
3221                 if (record_exists('context', 'contextlevel', CONTEXT_BLOCK, 'instanceid', $block->id)) {
3222                     delete_context(CONTEXT_BLOCK, $block->id);
3223                 }
3224
3225                 // fix for MDL-7164
3226                 // Get the block object and call instance_delete()
3227                 if (!$record = blocks_get_record($block->blockid)) {
3228                     $result = false;
3229                     continue;
3230                 }
3231                 if (!$obj = block_instance($record->name, $block)) {
3232                     $result = false;
3233                     continue;
3234                 }
3235                 // Return value ignored, in core mods this does not do anything, but just in case
3236                 // third party blocks might have stuff to clean up
3237                 // we execute this anyway
3238                 $obj->instance_delete();
3239             }
3240         } else {
3241             $result = false;
3242         }
3243     }
3244
3245 /// Delete any groups, removing members and grouping/course links first.
3246     require_once($CFG->dirroot.'/group/lib.php');
3247     groups_delete_groupings($courseid, true);
3248     groups_delete_groups($courseid, true);
3249
3250 /// Delete all related records in other tables that may have a courseid
3251 /// This array stores the tables that need to be cleared, as
3252 /// table_name => column_name that contains the course id.
3253
3254     $tablestoclear = array(
3255         'event' => 'courseid', // Delete events
3256         'log' => 'course', // Delete logs
3257         'course_sections' => 'course', // Delete any course stuff
3258         'course_modules' => 'course',
3259         'backup_courses' => 'courseid', // Delete scheduled backup stuff
3260         'backup_log' => 'courseid'
3261     );
3262     foreach ($tablestoclear as $table => $col) {
3263         if (delete_records($table, $col, $course->id)) {
3264             if ($showfeedback) {
3265                 notify($strdeleted . ' ' . $table);
3266             }
3267         } else {
3268             $result = false;
3269         }
3270     }
3271
3272
3273 /// Clean up metacourse stuff
3274
3275     if ($course->metacourse) {
3276         delete_records("course_meta","parent_course",$course->id);
3277         sync_metacourse($course->id); // have to do it here so the enrolments get nuked. sync_metacourses won't find it without the id.
3278         if ($showfeedback) {
3279             notify("$strdeleted course_meta");
3280         }
3281     } else {
3282         if ($parents = get_records("course_meta","child_course",$course->id)) {
3283             foreach ($parents as $parent) {
3284                 remove_from_metacourse($parent->parent_course,$parent->child_course); // this will do the unenrolments as well.
3285             }
3286             if ($showfeedback) {
3287                 notify("$strdeleted course_meta");
3288             }
3289         }
3290     }
3291
3292 /// Delete questions and question categories
3293     question_delete_course($course, $showfeedback);
3294
3295 /// Delete all roles and overiddes in the course context (but keep the course context)
3296     if ($courseid != SITEID) {
3297         delete_context(CONTEXT_COURSE, $course->id);
3298     }
3299
3300     // fix for MDL-9016
3301     // clear the cache because the course context is deleted, and
3302     // we don't want to write assignment, overrides and context_rel table
3303     // with this old context id!
3304     get_context_instance('clearcache');
3305     return $result;
3306 }
3307
3308
3309 /**
3310  * This function will empty a course of USER data as much as
3311 /// possible. It will retain the activities and the structure
3312 /// of the course.
3313  *
3314  * @uses $USER
3315  * @uses $SESSION
3316  * @uses $CFG
3317  * @param object $data an object containing all the boolean settings and courseid
3318  * @param bool $showfeedback  if false then do it all silently
3319  * @return bool
3320  * @todo Finish documenting this function
3321  */
3322 function reset_course_userdata($data, $showfeedback=true) {
3323
3324     global $CFG, $USER, $SESSION;
3325     require_once($CFG->dirroot.'/group/lib.php');
3326
3327     $result = true;
3328
3329     $strdeleted = get_string('deleted');
3330
3331     // Look in every instance of every module for data to delete
3332
3333     if ($allmods = get_records('modules') ) {
3334         foreach ($allmods as $mod) {
3335             $modname = $mod->name;
3336             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3337             $moddeleteuserdata = $modname .'_delete_userdata';   // Function to delete user data
3338             if (file_exists($modfile)) {
3339                 @include_once($modfile);
3340                 if (function_exists($moddeleteuserdata)) {
3341                     $moddeleteuserdata($data, $showfeedback);
3342                 }
3343             }
3344         }
3345     } else {
3346         error('No modules are installed!');
3347     }
3348
3349     // Delete other stuff
3350     $coursecontext = get_context_instance(CONTEXT_COURSE, $data->courseid);
3351
3352     if (!empty($data->reset_students) or !empty($data->reset_teachers)) {
3353         $teachers     = array_keys(get_users_by_capability($coursecontext, 'moodle/course:update'));
3354         $participants = array_keys(get_users_by_capability($coursecontext, 'moodle/course:view'));
3355         $students     = array_diff($participants, $teachers);
3356
3357         if (!empty($data->reset_students)) {
3358             foreach ($students as $studentid) {
3359                 role_unassign(0, $studentid, 0, $coursecontext->id);
3360             }
3361             if ($showfeedback) {
3362                 notify($strdeleted .' '.get_string('students'), 'notifysuccess');
3363             }
3364
3365             /// Delete group members (but keep the groups)
3366             $result = groups_delete_group_members($data->courseid, $showfeedback) && $result;
3367         }
3368
3369         if (!empty($data->reset_teachers)) {
3370             foreach ($teachers as $teacherid) {
3371                 role_unassign(0, $teacherid, 0, $coursecontext->id);
3372             }
3373             if ($showfeedback) {
3374                 notify($strdeleted .' '.get_string('teachers'), 'notifysuccess');
3375             }
3376         }
3377     }
3378
3379     if (!empty($data->reset_groups)) {
3380             $result = groups_delete_groupings($data->courseid, $showfeedback) && $result;
3381             $result = groups_delete_groups($data->courseid, $showfeedback) && $result;
3382     }
3383
3384     if (!empty($data->reset_events)) {
3385         if (delete_records('event', 'courseid', $data->courseid)) {
3386             if ($showfeedback) {
3387                 notify($strdeleted .' event', 'notifysuccess');
3388             }
3389         } else {
3390             $result = false;
3391         }
3392     }
3393
3394     if (!empty($data->reset_logs)) {
3395         if (delete_records('log', 'course', $data->courseid)) {
3396             if ($showfeedback) {
3397                 notify($strdeleted .' log', 'notifysuccess');
3398             }
3399         } else {
3400             $result = false;
3401         }
3402     }
3403
3404     // deletes all role assignments, and local override, these have no courseid in table and needs separate process
3405     $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
3406     delete_records('role_capabilities', 'contextid', $context->id);
3407
3408     return $result;
3409 }
3410
3411 function generate_email_processing_address($modid,$modargs) {
3412     global $CFG;
3413
3414     if (empty($CFG->siteidentifier)) {    // Unique site identification code
3415         set_config('siteidentifier', random_string(32));
3416     }
3417
3418     $header = $CFG->mailprefix . substr(base64_encode(pack('C',$modid)),0,2).$modargs;
3419     return $header . substr(md5($header.$CFG->siteidentifier),0,16).'@'.$CFG->maildomain;
3420 }
3421
3422
3423 function moodle_process_email($modargs,$body) {
3424     // the first char should be an unencoded letter. We'll take this as an action
3425     switch ($modargs{0}) {
3426         case 'B': { // bounce
3427             list(,$userid) = unpack('V',base64_decode(substr($modargs,1,8)));
3428             if ($user = get_record_select("user","id=$userid","id,email")) {
3429                 // check the half md5 of their email
3430                 $md5check = substr(md5($user->email),0,16);
3431                 if ($md5check == substr($modargs, -16)) {
3432                     set_bounce_count($user);
3433                 }
3434                 // else maybe they've already changed it?
3435             }
3436         }
3437         break;
3438         // maybe more later?
3439     }
3440 }
3441
3442 /// CORRESPONDENCE  ////////////////////////////////////////////////
3443
3444 /**
3445  * Send an email to a specified user
3446  *
3447  * @uses $CFG
3448  * @uses $FULLME
3449  * @uses SITEID
3450  * @param user $user  A {@link $USER} object
3451  * @param user $from A {@link $USER} object
3452  * @param string $subject plain text subject line of the email
3453  * @param string $messagetext plain text version of the message
3454  * @param string $messagehtml complete html version of the message (optional)
3455  * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
3456  * @param string $attachname the name of the file (extension indicates MIME)
3457  * @param bool $usetrueaddress determines whether $from email address should
3458  *          be sent out. Will be overruled by user profile setting for maildisplay
3459  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3460  *          was blocked by user and "false" if there was another sort of error.
3461  */
3462 function email_to_user($user, $from, $subject, $messagetext, $messagehtml='', $attachment='', $attachname='', $usetrueaddress=true, $replyto='', $replytoname='') {
3463
3464     global $CFG, $FULLME;
3465
3466     include_once($CFG->libdir .'/phpmailer/class.phpmailer.php');
3467
3468 /// We are going to use textlib services here
3469     $textlib = textlib_get_instance();
3470
3471     if (empty($user)) {
3472         return false;
3473     }
3474
3475     // skip mail to suspended users
3476     if (isset($user->auth) && $user->auth=='nologin') {
3477         return true;
3478     }
3479
3480     if (!empty($user->emailstop)) {
3481         return 'emailstop';
3482     }
3483
3484     if (over_bounce_threshold($user)) {
3485         error_log("User $user->id (".fullname($user).") is over bounce threshold! Not sending.");
3486         return false;
3487     }
3488
3489     $mail = new phpmailer;
3490
3491     $mail->Version = 'Moodle '. $CFG->version;           // mailer version
3492     $mail->PluginDir = $CFG->libdir .'/phpmailer/';      // plugin directory (eg smtp plugin)
3493
3494     $mail->CharSet = 'UTF-8';
3495
3496     if ($CFG->smtphosts == 'qmail') {
3497         $mail->IsQmail();                              // use Qmail system
3498
3499     } else if (empty($CFG->smtphosts)) {
3500         $mail->IsMail();                               // use PHP mail() = sendmail
3501
3502     } else {
3503         $mail->IsSMTP();                               // use SMTP directly
3504         if (!empty($CFG->debugsmtp)) {
3505             echo '<pre>' . "\n";
3506             $mail->SMTPDebug = true;
3507         }
3508         $mail->Host = $CFG->smtphosts;               // specify main and backup servers
3509
3510         if ($CFG->smtpuser) {                          // Use SMTP authentication
3511             $mail->SMTPAuth = true;
3512             $mail->Username = $CFG->smtpuser;
3513             $mail->Password = $CFG->smtppass;
3514         }
3515     }
3516
3517     $supportuser = generate_email_supportuser();
3518
3519
3520     // make up an email address for handling bounces
3521     if (!empty($CFG->handlebounces)) {
3522         $modargs = 'B'.base64_encode(pack('V',$user->id)).substr(md5($user->email),0,16);
3523         $mail->Sender = generate_email_processing_address(0,$modargs);
3524     } else {
3525         $mail->Sender   = $supportuser->email;
3526     }
3527
3528     if (is_string($from)) { // So we can pass whatever we want if there is need
3529         $mail->From     = $CFG->noreplyaddress;
3530         $mail->FromName = $from;
3531     } else if ($usetrueaddress and $from->maildisplay) {
3532         $mail->From     = $from->email;
3533         $mail->FromName = fullname($from);
3534     } else {
3535         $mail->From     = $CFG->noreplyaddress;
3536         $mail->FromName = fullname($from);
3537         if (empty($replyto)) {
3538             $mail->AddReplyTo($CFG->noreplyaddress,get_string('noreplyname'));
3539         }
3540     }
3541
3542     if (!empty($replyto)) {
3543         $mail->AddReplyTo($replyto,$replytoname);
3544     }
3545
3546     $mail->Subject = substr(stripslashes($subject), 0, 900);
3547
3548     $mail->AddAddress($user->email, fullname($user) );
3549
3550     $mail->WordWrap = 79;                               // set word wrap
3551
3552     if (!empty($from->customheaders)) {                 // Add custom headers
3553         if (is_array($from->customheaders)) {
3554             foreach ($from->customheaders as $customheader) {
3555                 $mail->AddCustomHeader($customheader);
3556             }
3557         } else {
3558             $mail->AddCustomHeader($from->customheaders);
3559         }
3560     }
3561
3562     if (!empty($from->priority)) {
3563         $mail->Priority = $from->priority;
3564     }
3565
3566     if ($messagehtml && $user->mailformat == 1) { // Don't ever send HTML to users who don't want it
3567         $mail->IsHTML(true);
3568         $mail->Encoding = 'quoted-printable';           // Encoding to use
3569         $mail->Body    =  $messagehtml;
3570         $mail->AltBody =  "\n$messagetext\n";
3571     } else {
3572         $mail->IsHTML(false);
3573         $mail->Body =  "\n$messagetext\n";
3574     }
3575
3576     if ($attachment && $attachname) {
3577         if (ereg( "\\.\\." ,$attachment )) {    // Security check for ".." in dir path
3578             $mail->AddAddress($supportuser->email, fullname($supportuser, true) );
3579             $mail->AddStringAttachment('Error in attachment.  User attempted to attach a filename with a unsafe name.', 'error.txt', '8bit', 'text/plain');
3580         } else {
3581             require_once($CFG->libdir.'/filelib.php');
3582             $mimetype = mimeinfo('type', $attachname);
3583             $mail->AddAttachment($CFG->dataroot .'/'. $attachment, $attachname, 'base64', $mimetype);
3584         }
3585     }
3586
3587
3588
3589 /// If we are running under Unicode and sitemailcharset or allowusermailcharset are set, convert the email
3590 /// encoding to the specified one
3591     if ((!empty($CFG->sitemailcharset) || !empty($CFG->allowusermailcharset))) {
3592     /// Set it to site mail charset
3593         $charset = $CFG->sitemailcharset;
3594     /// Overwrite it with the user mail charset
3595         if (!empty($CFG->allowusermailcharset)) {
3596             if ($useremailcharset = get_user_preferences('mailcharset', '0', $user->id)) {
3597                 $charset = $useremailcharset;
3598             }
3599         }
3600     /// If it has changed, convert all the necessary strings
3601         $charsets = get_list_of_charsets();
3602         unset($charsets['UTF-8']);
3603         if (in_array($charset, $charsets)) {
3604         /// Save the new mail charset
3605             $mail->CharSet = $charset;
3606         /// And convert some strings
3607             $mail->FromName = $textlib->convert($mail->FromName, 'utf-8', $mail->CharSet); //From Name
3608             foreach ($mail->ReplyTo as $key => $rt) {                                      //ReplyTo Names
3609                 $mail->ReplyTo[$key][1] = $textlib->convert($rt, 'utf-8', $mail->CharSet);
3610             }
3611             $mail->Subject = $textlib->convert($mail->Subject, 'utf-8', $mail->CharSet);   //Subject
3612             foreach ($mail->to as $key => $to) {
3613                 $mail->to[$key][1] = $textlib->convert($to, 'utf-8', $mail->CharSet);      //To Names
3614             }
3615             $mail->Body = $textlib->convert($mail->Body, 'utf-8', $mail->CharSet);         //Body
3616             $mail->AltBody = $textlib->convert($mail->AltBody, 'utf-8', $mail->CharSet);   //Subject
3617         }
3618     }
3619
3620     if ($mail->Send()) {
3621         set_send_count($user);
3622         $mail->IsSMTP();                               // use SMTP directly
3623         if (!empty($CFG->debugsmtp)) {
3624             echo '</pre>';
3625         }
3626         return true;
3627     } else {
3628         mtrace('ERROR: '. $mail->ErrorInfo);
3629         add_to_log(SITEID, 'library', 'mailer', $FULLME, 'ERROR: '. $mail->ErrorInfo);
3630         if (!empty($CFG->debugsmtp)) {
3631             echo '</pre>';
3632         }
3633         return false;
3634     }
3635 }
3636
3637 /**
3638  * Generate a signoff for emails based on support settings
3639  *
3640  */
3641 function generate_email_signoff() {
3642     global $CFG;
3643
3644     $signoff = "\n";
3645     if (!empty($CFG->supportname)) {
3646         $signoff .= $CFG->supportname."\n";
3647     }
3648     if (!empty($CFG->supportemail)) {
3649         $signoff .= $CFG->supportemail."\n";
3650     }
3651     if (!empty($CFG->supportpage)) {
3652         $signoff .= $CFG->supportpage."\n";
3653     }
3654     return $signoff;
3655 }
3656
3657 /**
3658  * Generate a fake user for emails based on support settings
3659  *
3660  */
3661 function generate_email_supportuser() {
3662
3663     global $CFG;
3664
3665     static $supportuser;
3666
3667     if (!empty($supportuser)) {
3668         return $supportuser;
3669     }
3670
3671     $supportuser = new object;
3672     $supportuser->email = $CFG->supportemail ? $CFG->supportemail : $CFG->noreplyaddress;
3673     $supportuser->firstname = $CFG->supportname ? $CFG->supportname : get_string('noreplyname');
3674     $supportuser->lastname = '';
3675
3676     return $supportuser;
3677 }
3678
3679
3680 /**
3681  * Sets specified user's password and send the new password to the user via email.
3682  *
3683  * @uses $CFG
3684  * @param user $user A {@link $USER} object
3685  * @return boolean|string Returns "true" if mail was sent OK, "emailstop" if email
3686  *          was blocked by user and "false" if there was another sort of error.
3687  */
3688 function setnew_password_and_mail($user) {
3689
3690     global $CFG;
3691
3692     $site  = get_site();
3693
3694     $supportuser = generate_email_supportuser();
3695
3696     $newpassword = generate_password();
3697
3698     if (! set_field('user', 'password', md5($newpassword), 'id', $user->id) ) {
3699         trigger_error('Could not set user password!');
3700         return false;
3701     }
3702
3703     $a = new object();
3704     $a->firstname   = fullname($user, true);
3705     $a->sitename    = format_string($site->fullname);
3706     $a->username    = $user->username;
3707     $a->newpassword = $newpassword;
3708     $a->link        = $CFG->wwwroot .'/login/';
3709     $a->signoff     = generate_email_signoff();
3710
3711     $message = get_string('newusernewpasswordtext', '', $a);
3712
3713     $subject  = format_string($site->fullname) .': '. get_string('newusernewpasswordsubj');
3714
3715     return email_to_user($user, $supportuser, $subject, $message);
3716
3717 }
3718
3719 /**
3720  * Resets specified user's password and send the new password to the user via email.
3721  *
3722  * @uses $CFG
3723  * @param user $user A {@link $USER} object
3724  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3725  *          was blocked by user and "false" if there was another sort of error.
3726  */
3727 function reset_password_and_mail($user) {
3728
3729     global $CFG;
3730
3731     $site  = get_site();
3732     $supportuser = generate_email_supportuser();
3733
3734     $userauth = get_auth_plugin($user->auth);
3735     if (!$userauth->can_reset_password() or !is_enabled_auth($user->auth)) {
3736         trigger_error("Attempt to reset user password for user $user->username with Auth $user->auth.");
3737         return false;
3738     }
3739
3740     $newpassword = generate_password();
3741
3742     if (!$userauth->user_update_password(addslashes_recursive($user), addslashes($newpassword))) {
3743         error("Could not set user password!");
3744     }
3745
3746     $a = new object();
3747     $a->firstname = $user->firstname;
3748     $a->sitename = format_string($site->fullname);
3749     $a->username = $user->username;
3750     $a->newpassword = $newpassword;
3751     $a->link = $CFG->httpswwwroot .'/login/change_password.php';
3752     $a->signoff = generate_email_signoff();
3753
3754     $message = get_string('newpasswordtext', '', $a);
3755
3756     $subject  = format_string($site->fullname) .': '. get_string('changedpassword');
3757
3758     return email_to_user($user, $supportuser, $subject, $message);
3759
3760 }
3761
3762 /**
3763  * Send email to specified user with confirmation text and activation link.
3764  *
3765  * @uses $CFG
3766  * @param user $user A {@link $USER} object
3767  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3768  *          was blocked by user and "false" if there was another sort of error.
3769  */
3770  function send_confirmation_email($user) {
3771
3772     global $CFG;
3773
3774     $site = get_site();
3775     $supportuser = generate_email_supportuser();
3776
3777     $data = new object();
3778     $data->firstname = fullname($user);
3779     $data->sitename = format_string($site->fullname);
3780     $data->admin = generate_email_signoff();
3781
3782     $subject = get_string('emailconfirmationsubject', '', format_string($site->fullname));
3783
3784     $data->link = $CFG->wwwroot .'/login/confirm.php?data='. $user->secret .'/'. urlencode($user->username);
3785     $message     = get_string('emailconfirmation', '', $data);
3786     $messagehtml = text_to_html(get_string('emailconfirmation', '', $data), false, false, true);
3787
3788     $user->mailformat = 1;  // Always send HTML version as well
3789
3790     return email_to_user($user, $supportuser, $subject, $message, $messagehtml);
3791
3792 }
3793
3794 /**
3795  * send_password_change_confirmation_email.
3796  *
3797  * @uses $CFG
3798  * @param user $user A {@link $USER} object
3799  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3800  *          was blocked by user and "false" if there was another sort of error.
3801  */
3802 function send_password_change_confirmation_email($user) {
3803
3804     global $CFG;
3805
3806     $site = get_site();
3807     $supportuser = generate_email_supportuser();
3808
3809     $data = new object();
3810     $data->firstname = $user->firstname;
3811     $data->sitename = format_string($site->fullname);
3812     $data->link = $CFG->httpswwwroot .'/login/forgot_password.php?p='. $user->secret .'&s='. urlencode($user->username);
3813     $data->admin = generate_email_signoff();
3814
3815     $message = get_string('emailpasswordconfirmation', '', $data);
3816     $subject = get_string('emailpasswordconfirmationsubject', '', format_string($site->fullname));
3817
3818     return email_to_user($user, $supportuser, $subject, $message);
3819
3820 }
3821
3822 /**
3823  * send_password_change_info.
3824  *
3825  * @uses $CFG
3826  * @param user $user A {@link $USER} object
3827  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3828  *          was blocked by user and "false" if there was another sort of error.
3829  */
3830 function send_password_change_info($user) {
3831
3832     global $CFG;
3833
3834     $site = get_site();
3835     $supportuser = generate_email_supportuser();
3836     $systemcontext = get_context_instance(CONTEXT_SYSTEM);
3837
3838     $data = new object();
3839     $data->firstname = $user->firstname;
3840     $data->sitename = format_string($site->fullname);
3841     $data->admin = generate_email_signoff();
3842
3843     $userauth = get_auth_plugin($user->auth);
3844
3845     if (!is_enabled_auth($user->auth) or $user->auth == 'nologin') {
3846         $message = get_string('emailpasswordchangeinfodisabled', '', $data);
3847         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3848         return email_to_user($user, $supportuser, $subject, $message);
3849     }
3850
3851     if ($userauth->can_change_password() and $userauth->change_password_url()) {
3852         // we have some external url for password changing
3853         $data->link .= $userauth->change_password_url();
3854
3855     } else {
3856         //no way to change password, sorry
3857         $data->link = '';
3858     }
3859
3860     if (!empty($data->link) and has_capability('moodle/user:changeownpassword', $systemcontext, $user->id)) {
3861         $message = get_string('emailpasswordchangeinfo', '', $data);
3862         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3863     } else {
3864         $message = get_string('emailpasswordchangeinfofail', '', $data);
3865         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3866     }
3867
3868     return email_to_user($user, $supportuser, $subject, $message);
3869
3870 }
3871
3872 /**
3873  * Check that an email is allowed.  It returns an error message if there
3874  * was a problem.
3875  *
3876  * @uses $CFG
3877  * @param  string $email Content of email
3878  * @return string|false
3879  */
3880 function email_is_not_allowed($email) {
3881
3882     global $CFG;
3883
3884     if (!empty($CFG->allowemailaddresses)) {
3885         $allowed = explode(' ', $CFG->allowemailaddresses);
3886         foreach ($allowed as $allowedpattern) {
3887             $allowedpattern = trim($allowedpattern);
3888             if (!$allowedpattern) {
3889                 continue;
3890             }
3891             if (strpos(strrev($email), strrev('@'.$allowedpattern)) === 0) { // Match!   (bug 5250)
3892                 return false;
3893             }
3894         }
3895         return get_string('emailonlyallowed', '', $CFG->allowemailaddresses);
3896
3897     } else if (!empty($CFG->denyemailaddresses)) {
3898         $denied = explode(' ', $CFG->denyemailaddresses);
3899         foreach ($denied as $deniedpattern) {
3900             $deniedpattern = trim($deniedpattern);
3901             if (!$deniedpattern) {
3902                 continue;
3903             }
3904             if (strpos(strrev($email), strrev('@'.$deniedpattern)) === 0) { // Match!   (bug 5250)
3905                 return get_string('emailnotallowed', '', $CFG->denyemailaddresses);
3906             }
3907         }
3908     }
3909
3910     return false;
3911 }
3912
3913 function email_welcome_message_to_user($course, $user=NULL) {
3914     global $CFG, $USER;
3915
3916     if (empty($user)) {
3917         if (!isloggedin()) {
3918             return false;
3919         }
3920         $user = $USER;
3921     }
3922
3923     if (!empty($course->welcomemessage)) {
3924         $subject = get_string('welcometocourse', '', format_string($course->fullname));
3925
3926         $a->coursename = $course->fullname;
3927         $a->profileurl = "$CFG->wwwroot/user/view.php?id=$USER->id&course=$course->id";
3928         //$message = get_string("welcometocoursetext", "", $a);
3929         $message = $course->welcomemessage;
3930
3931         if (! $teacher = get_teacher($course->id)) {
3932             $teacher = get_admin();
3933         }
3934         email_to_user($user, $teacher, $subject, $message);
3935     }
3936 }
3937
3938 /// FILE HANDLING  /////////////////////////////////////////////
3939
3940
3941 /**
3942  * Makes an upload directory for a particular module.
3943  *
3944  * @uses $CFG
3945  * @param int $courseid The id of the course in question - maps to id field of 'course' table.
3946  * @return string|false Returns full path to directory if successful, false if not
3947  */
3948 function make_mod_upload_directory($courseid) {
3949     global $CFG;
3950
3951     if (! $moddata = make_upload_directory($courseid .'/'. $CFG->moddata)) {
3952         return false;
3953     }
3954
3955     $strreadme = get_string('readme');
3956
3957     if (file_exists($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt')) {
3958         copy($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
3959     } else {
3960         copy($CFG->dirroot .'/lang/en_utf8/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
3961     }
3962     return $moddata;
3963 }
3964
3965 /**
3966  * Returns current name of file on disk if it exists.
3967  *
3968  * @param string $newfile File to be verified
3969  * @return string Current name of file on disk if true
3970  */
3971 function valid_uploaded_file($newfile) {
3972     if (empty($newfile)) {
3973         return '';
3974     }
3975     if (is_uploaded_file($newfile['tmp_name']) and $newfile['size'] > 0) {
3976         return $newfile['tmp_name'];
3977     } else {
3978         return '';
3979     }
3980 }
3981
3982 /**
3983  * Returns the maximum size for uploading files.
3984  *
3985  * There are seven possible upload limits:
3986  * 1. in Apache using LimitRequestBody (no way of checking or changing this)
3987  * 2. in php.ini for 'upload_max_filesize' (can not be changed inside PHP)
3988  * 3. in .htaccess for 'upload_max_filesize' (can not be changed inside PHP)
3989  * 4. in php.ini for 'post_max_size' (can not be changed inside PHP)
3990  * 5. by the Moodle admin in $CFG->maxbytes
3991  * 6. by the teacher in the current course $course->maxbytes
3992  * 7. by the teacher for the current module, eg $assignment->maxbytes
3993  *
3994  * These last two are passed to this function as arguments (in bytes).
3995  * Anything defined as 0 is ignored.
3996  * The smallest of all the non-zero numbers is returned.
3997  *
3998  * @param int $sizebytes ?
3999  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4000  * @param int $modulebytes Current module ->maxbytes (in bytes)
4001  * @return int The maximum size for uploading files.
4002  * @todo Finish documenting this function
4003  */
4004 function get_max_upload_file_size($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4005
4006     if (! $filesize = ini_get('upload_max_filesize')) {
4007         $filesize = '5M';
4008     }
4009     $minimumsize = get_real_size($filesize);
4010
4011     if ($postsize = ini_get('post_max_size')) {
4012         $postsize = get_real_size($postsize);
4013         if ($postsize < $minimumsize) {
4014             $minimumsize = $postsize;
4015         }
4016     }
4017
4018     if ($sitebytes and $sitebytes < $minimumsize) {
4019         $minimumsize = $sitebytes;
4020     }
4021
4022     if ($coursebytes and $coursebytes < $minimumsize) {
4023         $minimumsize = $coursebytes;
4024     }
4025
4026     if ($modulebytes and $modulebytes < $minimumsize) {
4027         $minimumsize = $modulebytes;
4028     }
4029
4030     return $minimumsize;
4031 }
4032
4033 /**
4034  * Related to {@link get_max_upload_file_size()} - this function returns an
4035  * array of possible sizes in an array, translated to the
4036  * local language.
4037  *
4038  * @uses SORT_NUMERIC
4039  * @param int $sizebytes ?
4040  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4041  * @param int $modulebytes Current module ->maxbytes (in bytes)
4042  * @return int
4043  * @todo Finish documenting this function
4044  */
4045 function get_max_upload_sizes($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4046     global $CFG;
4047
4048     if (!$maxsize = get_max_upload_file_size($sitebytes, $coursebytes, $modulebytes)) {
4049         return array();
4050     }
4051
4052     $filesize[$maxsize] = display_size($maxsize);
4053
4054     $sizelist = array(10240, 51200, 102400, 512000, 1048576, 2097152,
4055                       5242880, 10485760, 20971520, 52428800, 104857600);
4056
4057     // Allow maxbytes to be selected if it falls outside the above boundaries
4058     if( isset($CFG->maxbytes) && !in_array($CFG->maxbytes, $sizelist) ){
4059             $sizelist[] = $CFG->maxbytes;
4060     }
4061
4062     foreach ($sizelist as $sizebytes) {
4063        if ($sizebytes < $maxsize) {
4064            $filesize[$sizebytes] = display_size($sizebytes);
4065        }
4066     }
4067
4068     krsort($filesize, SORT_NUMERIC);
4069
4070     return $filesize;
4071 }
4072
4073 /**
4074  * If there has been an error uploading a file, print the appropriate error message
4075  * Numerical constants used as constant definitions not added until PHP version 4.2.0
4076  *
4077  * $filearray is a 1-dimensional sub-array of the $_FILES array
4078  * eg $filearray = $_FILES['userfile1']
4079  * If left empty then the first element of the $_FILES array will be used
4080  *
4081  * @uses $_FILES
4082  * @param array $filearray  A 1-dimensional sub-array of the $_FILES array
4083  * @param bool $returnerror If true then a string error message will be returned. Otherwise the user will be notified of the error in a notify() call.
4084  * @return bool|string
4085  */
4086 function print_file_upload_error($filearray = '', $returnerror = false) {
4087
4088     if ($filearray == '' or !isset($filearray['error'])) {
4089
4090         if (empty($_FILES)) return false;
4091
4092         $files = $_FILES; /// so we don't mess up the _FILES array for subsequent code
4093         $filearray = array_shift($files); /// use first element of array
4094     }
4095
4096     switch ($filearray['error']) {
4097
4098         case 0: // UPLOAD_ERR_OK
4099             if ($filearray['size'] > 0) {
4100                 $errmessage = get_string('uploadproblem', $filearray['name']);
4101             } else {
4102                 $errmessage = get_string('uploadnofilefound'); /// probably a dud file name
4103             }
4104             break;
4105
4106         case 1: // UPLOAD_ERR_INI_SIZE
4107             $errmessage = get_string('uploadserverlimit');
4108             break;
4109
4110         case 2: // UPLOAD_ERR_FORM_SIZE
4111             $errmessage = get_string('uploadformlimit');
4112             break;
4113
4114         case 3: // UPLOAD_ERR_PARTIAL
4115             $errmessage = get_string('uploadpartialfile');
4116             break;
4117
4118         case 4: // UPLOAD_ERR_NO_FILE
4119             $errmessage = get_string('uploadnofilefound');
4120             break;
4121
4122         default:
4123             $errmessage = get_string('uploadproblem', $filearray['name']);
4124     }
4125
4126     if ($returnerror) {
4127         return $errmessage;
4128     } else {
4129         notify($errmessage);
4130         return true;
4131     }
4132
4133 }
4134
4135 /**
4136  * handy function to loop through an array of files and resolve any filename conflicts
4137  * both in the array of filenames and for what is already on disk.
4138  * not really compatible with the similar function in uploadlib.php
4139  * but this could be used for files/index.php for moving files around.
4140  */
4141
4142 function resolve_filename_collisions($destination,$files,$format='%s_%d.%s') {
4143     foreach ($files as $k => $f) {
4144         if (check_potential_filename($destination,$f,$files)) {
4145             $bits = explode('.', $f);
4146             for ($i = 1; true; $i++) {
4147                 $try = sprintf($format, $bits[0], $i, $bits[1]);
4148                 if (!check_potential_filename($destination,$try,$files)) {
4149                     $files[$k] = $try;
4150                     break;
4151                 }
4152             }
4153         }
4154     }
4155     return $files;
4156 }
4157
4158 /**
4159  * @used by resolve_filename_collisions
4160  */
4161 function check_potential_filename($destination,$filename,$files) {
4162     if (file_exists($destination.'/'.$filename)) {
4163         return true;
4164     }
4165     if (count(array_keys($files,$filename)) > 1) {
4166         return true;
4167     }
4168     return false;
4169 }
4170
4171
4172 /**
4173  * Returns an array with all the filenames in
4174  * all subdirectories, relative to the given rootdir.
4175  * If excludefile is defined, then that file/directory is ignored
4176  * If getdirs is true, then (sub)directories are included in the output
4177  * If getfiles is true, then files are included in the output
4178  * (at least one of these must be true!)
4179  *
4180  * @param string $rootdir  ?
4181  * @param string $excludefile  If defined then the specified file/directory is ignored
4182  * @param bool $descend  ?
4183  * @param bool $getdirs  If true then (sub)directories are included in the output
4184  * @param bool $getfiles  If true then files are included in the output
4185  * @return array An array with all the filenames in
4186  * all subdirectories, relative to the given rootdir
4187  * @todo Finish documenting this function. Add examples of $excludefile usage.
4188  */
4189 function get_directory_list($rootdir, $excludefiles='', $descend=true, $getdirs=false, $getfiles=true) {
4190
4191     $dirs = array();
4192
4193     if (!$getdirs and !$getfiles) {   // Nothing to show
4194         return $dirs;
4195     }
4196
4197     if (!is_dir($rootdir)) {          // Must be a directory
4198         return $dirs;
4199     }
4200
4201     if (!$dir = opendir($rootdir)) {  // Can't open it for some reason
4202         return $dirs;
4203     }
4204
4205     if (!is_array($excludefiles)) {
4206         $excludefiles = array($excludefiles);
4207     }
4208
4209     while (false !== ($file = readdir($dir))) {
4210         $firstchar = substr($file, 0, 1);
4211         if ($firstchar == '.' or $file == 'CVS' or in_array($file, $excludefiles)) {
4212             continue;
4213         }
4214         $fullfile = $rootdir .'/'. $file;
4215         if (filetype($fullfile) == 'dir') {
4216             if ($getdirs) {
4217                 $dirs[] = $file;
4218             }
4219             if ($descend) {
4220                 $subdirs = get_directory_list($fullfile, $excludefiles, $descend, $getdirs, $getfiles);
4221                 foreach ($subdirs as $subdir) {
4222                     $dirs[] = $file .'/'. $subdir;
4223                 }
4224             }
4225         } else if ($getfiles) {
4226             $dirs[] = $file;
4227         }
4228     }
4229     closedir($dir);
4230
4231     asort($dirs);
4232
4233     return $dirs;
4234 }
4235
4236
4237 /**
4238  * Adds up all the files in a directory and works out the size.
4239  *
4240  * @param string $rootdir  ?
4241  * @param string $excludefile  ?
4242  * @return array
4243  * @todo Finish documenting this function
4244  */
4245 function get_directory_size($rootdir, $excludefile='') {
4246
4247     global $CFG;
4248
4249     // do it this way if we can, it's much faster
4250     if (!empty($CFG->pathtodu) && is_executable(trim($CFG->pathtodu))) {
4251         $command = trim($CFG->pathtodu).' -sk --apparent-size '.escapeshellarg($rootdir);
4252         $output = null;
4253         $return = null;
4254         exec($command,$output,$return);
4255         if (is_array($output)) {
4256             return get_real_size(intval($output[0]).'k'); // we told it to return k.
4257         }
4258     }
4259
4260     if (!is_dir($rootdir)) {          // Must be a directory
4261         return 0;
4262     }
4263
4264     if (!$dir = @opendir($rootdir)) {  // Can't open it for some reason
4265         return 0;
4266     }
4267
4268     $size = 0;
4269
4270     while (false !== ($file = readdir($dir))) {
4271         $firstchar = substr($file, 0, 1);
4272         if ($firstchar == '.' or $file == 'CVS' or $file == $excludefile) {
4273             continue;
4274         }
4275         $fullfile = $rootdir .'/'. $file;
4276         if (filetype($fullfile) == 'dir') {
4277             $size += get_directory_size($fullfile, $excludefile);
4278         } else {
4279             $size += filesize($fullfile);
4280         }
4281     }
4282     closedir($dir);
4283
4284     return $size;
4285 }
4286
4287 /**
4288  * Converts bytes into display form
4289  *
4290  * @param string $size  ?
4291  * @return string
4292  * @staticvar string $gb Localized string for size in gigabytes
4293  * @staticvar string $mb Localized string for size in megabytes
4294  * @staticvar string $kb Localized string for size in kilobytes
4295  * @staticvar string $b Localized string for size in bytes
4296  * @todo Finish documenting this function. Verify return type.
4297  */
4298 function display_size($size) {
4299
4300     static $gb, $mb, $kb, $b;
4301
4302     if (empty($gb)) {
4303         $gb = get_string('sizegb');
4304         $mb = get_string('sizemb');
4305         $kb = get_string('sizekb');
4306         $b  = get_string('sizeb');
4307     }
4308
4309     if ($size >= 1073741824) {
4310         $size = round($size / 1073741824 * 10) / 10 . $gb;
4311     } else if ($size >= 1048576) {
4312         $size = round($size / 1048576 * 10) / 10 . $mb;
4313     } else if ($size >= 1024) {
4314         $size = round($size / 1024 * 10) / 10 . $kb;
4315     } else {
4316         $size = $size .' '. $b;
4317     }
4318     return $size;
4319 }
4320
4321 /**
4322  * Cleans a given filename by removing suspicious or troublesome characters
4323  * Only these are allowed: alphanumeric _ - .
4324  * Unicode characters can be enabled by setting $CFG->unicodecleanfilename = true in config.php
4325  *
4326  * WARNING: unicode characters may not be compatible with zip compression in backup/restore,
4327  *          because native zip binaries do weird character conversions. Use PHP zipping instead.
4328  *
4329  * @param string $string  file name
4330  * @return string cleaned file name
4331  */
4332 function clean_filename($string) {
4333     global $CFG;
4334     if (empty($CFG->unicodecleanfilename)) {
4335         $textlib = textlib_get_instance();
4336         $string = $textlib->specialtoascii($string);
4337         $string = preg_replace('/[^\.a-zA-Z\d\_-]/','_', $string ); // only allowed chars
4338     } else {
4339         //clean only ascii range
4340         $string = preg_replace("/[\\000-\\x2c\\x2f\\x3a-\\x40\\x5b-\\x5e\\x60\\x7b-\\177]/s", '_', $string);
4341     }
4342     $string = preg_replace("/_+/", '_', $string);
4343     $string = preg_replace("/\.\.+/", '.', $string);
4344     return $string;
4345 }
4346
4347
4348 /// STRING TRANSLATION  ////////////////////////////////////////
4349
4350 /**
4351  * Returns the code for the current language
4352  *
4353  * @uses $CFG
4354  * @param $USER
4355  * @param $SESSION
4356  * @return string
4357  */
4358 function current_language() {
4359     global $CFG, $USER, $SESSION, $COURSE;
4360
4361     if (!empty($COURSE->id) and $COURSE->id != SITEID and !empty($COURSE->lang)) {    // Course language can override all other settings for this page
4362         $return = $COURSE->lang;
4363
4364     } else if (!empty($SESSION->lang)) {    // Session language can override other settings
4365         $return = $SESSION->lang;
4366
4367     } else if (!empty($USER->lang)) {
4368         $return = $USER->lang;
4369
4370     } else {
4371         $return = $CFG->lang;
4372     }
4373
4374     if ($return == 'en') {
4375         $return = 'en_utf8';
4376     }
4377
4378     return $return;
4379 }
4380
4381 /**
4382  * Prints out a translated string.
4383  *
4384  * Prints out a translated string using the return value from the {@link get_string()} function.
4385  *
4386  * Example usage of this function when the string is in the moodle.php file:<br/>
4387  * <code>
4388  * echo '<strong>';
4389  * print_string('wordforstudent');
4390  * echo '</strong>';
4391  * </code>
4392  *
4393  * Example usage of this function when the string is not in the moodle.php file:<br/>
4394  * <code>
4395  * echo '<h1>';
4396  * print_string('typecourse', 'calendar');
4397  * echo '</h1>';
4398  * </code>
4399  *
4400  * @param string $identifier The key identifier for the localized string
4401  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4402  * @param mixed $a An object, string or number that can be used
4403  * within translation strings
4404  */
4405 function print_string($identifier, $module='', $a=NULL) {
4406     echo get_string($identifier, $module, $a);
4407 }
4408
4409 /**
4410  * fix up the optional data in get_string()/print_string() etc
4411  * ensure possible sprintf() format characters are escaped correctly
4412  * needs to handle arbitrary strings and objects
4413  * @param mixed $a An object, string or number that can be used
4414  * @return mixed the supplied parameter 'cleaned'
4415  */
4416 function clean_getstring_data( $a ) {
4417     if (is_string($a)) {
4418         return str_replace( '%','%%',$a );
4419     }
4420     elseif (is_object($a)) {
4421         $a_vars = get_object_vars( $a );
4422         $new_a_vars = array();
4423         foreach ($a_vars as $fname => $a_var) {
4424             $new_a_vars[$fname] = clean_getstring_data( $a_var );
4425         }
4426         return (object)$new_a_vars;
4427     }
4428     else {
4429         return $a;
4430     }
4431 }
4432
4433 /**
4434  * @return array places to look for lang strings based on the prefix to the
4435  * module name. For example qtype_ in question/type. Used by get_string and
4436  * help.php.
4437  */
4438 function places_to_search_for_lang_strings() {
4439     global $CFG;
4440
4441     return array(
4442         '__exceptions' => array('moodle', 'langconfig'),
4443         'assignment_' => array('mod/assignment/type'),
4444         'auth_' => array('auth'),
4445         'block_' => array('blocks'),
4446         'datafield_' => array('mod/data/field'),
4447         'datapreset_' => array('mod/data/preset'),
4448         'enrol_' => array('enrol'),
4449         'format_' => array('course/format'),
4450         'qtype_' => array('question/type'),
4451         'report_' => array($CFG->admin.'/report', 'course/report', 'mod/quiz/report'),
4452         'resource_' => array('mod/resource/type'),
4453         'gradereport_' => array('grade/report'),
4454         'gradeimport_' => array('grade/import'),
4455         'gradeexport_' => array('grade/export'),
4456         '' => array('mod')
4457     );
4458 }
4459
4460 /**
4461  * Returns a localized string.
4462  *
4463  * Returns the translated string specified by $identifier as
4464  * for $module.  Uses the same format files as STphp.
4465  * $a is an object, string or number that can be used
4466  * within translation strings
4467  *
4468  * eg "hello \$a->firstname \$a->lastname"
4469  * or "hello \$a"
4470  *
4471  * If you would like to directly echo the localized string use
4472  * the function {@link print_string()}
4473  *
4474  * Example usage of this function involves finding the string you would
4475  * like a local equivalent of and using its identifier and module information
4476  * to retrive it.<br/>
4477  * If you open moodle/lang/en/moodle.php and look near line 1031
4478  * you will find a string to prompt a user for their word for student
4479  * <code>
4480  * $string['wordforstudent'] = 'Your word for Student';
4481  * </code>
4482  * So if you want to display the string 'Your word for student'
4483  * in any language that supports it on your site
4484  * you just need to use the identifier 'wordforstudent'
4485  * <code>
4486  * $mystring = '<strong>'. get_string('wordforstudent') .'</strong>';
4487 or
4488  * </code>
4489  * If the string you want is in another file you'd take a slightly
4490  * different approach. Looking in moodle/lang/en/calendar.php you find
4491  * around line 75:
4492  * <code>
4493  * $string['typecourse'] = 'Course event';
4494  * </code>
4495  * If you want to display the string "Course event" in any language
4496  * supported you would use the identifier 'typecourse' and the module 'calendar'
4497  * (because it is in the file calendar.php):
4498  * <code>
4499  * $mystring = '<h1>'. get_string('typecourse', 'calendar') .'</h1>';
4500  * </code>
4501  *
4502  * As a last resort, should the identifier fail to map to a string
4503  * the returned string will be [[ $identifier ]]
4504  *
4505  * @uses $CFG
4506  * @param string $identifier The key identifier for the localized string
4507  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4508  * @param mixed $a An object, string or number that can be used
4509  * within translation strings
4510  * @param array $extralocations An array of strings with other locations to look for string files
4511  * @return string The localized string.
4512  */
4513 function get_string($identifier, $module='', $a=NULL, $extralocations=NULL) {
4514
4515     global $CFG;
4516
4517 /// originally these special strings were stored in moodle.php now we are only in langconfig.php
4518     $langconfigstrs = array('alphabet', 'backupnameformat', 'decsep', 'firstdayofweek', 'listsep', 'locale',
4519                             'localewin', 'localewincharset', 'oldcharset',
4520                             'parentlanguage', 'strftimedate', 'strftimedateshort', 'strftimedatetime',
4521                             'strftimedaydate', 'strftimedaydatetime', 'strftimedayshort', 'strftimedaytime',
4522                             'strftimemonthyear', 'strftimerecent', 'strftimerecentfull', 'strftimetime',
4523                             'thischarset', 'thisdirection', 'thislanguage');
4524
4525     $filetocheck = 'langconfig.php';
4526     $defaultlang = 'en_utf8';
4527     if (in_array($identifier, $langconfigstrs)) {
4528         $module = 'langconfig';  //This strings are under langconfig.php for 1.6 lang packs
4529     }
4530
4531     $lang = current_language();
4532
4533     if ($module == '') {
4534         $module = 'moodle';
4535     }
4536
4537     // if $a happens to have % in it, double it so sprintf() doesn't break
4538     if ($a) {
4539         $a = clean_getstring_data( $a );
4540     }
4541
4542 /// Define the two or three major locations of language strings for this module
4543     $locations = array();
4544
4545     if (!empty($extralocations)) {   // Calling code has a good idea where to look
4546         if (is_array($extralocations)) {
4547             $locations += $extralocations;
4548         } else if (is_string($extralocations)) {
4549             $locations[] = $extralocations;
4550         } else {
4551             debugging('Bad lang path provided');
4552         }
4553     }
4554
4555     if (isset($CFG->running_installer)) {
4556         $module = 'installer';
4557         $filetocheck = 'installer.php';
4558         $locations[] = $CFG->dirroot.'/install/lang/';
4559         $locations[] = $CFG->dataroot.'/lang/';
4560         $locations[] = $CFG->dirroot.'/lang/';
4561         $defaultlang = 'en_utf8';
4562     } else {
4563         $locations[] = $CFG->dataroot.'/lang/';
4564         $locations[] = $CFG->dirroot.'/lang/';
4565     }
4566
4567 /// Add extra places to look for strings for particular plugin types.
4568     $rules = places_to_search_for_lang_strings();
4569     $exceptions = $rules['__exceptions'];
4570     unset($rules['__exceptions']);
4571
4572     if (!in_array($module, $exceptions)) {
4573         $dividerpos = strpos($module, '_');
4574         if ($dividerpos === false) {
4575             $type = '';
4576             $plugin = $module;
4577         } else {
4578             $type = substr($module, 0, $dividerpos + 1);
4579             $plugin = substr($module, $dividerpos + 1);
4580         }
4581         if (!empty($rules[$type])) {
4582             foreach ($rules[$type] as $location) {
4583                 $locations[] = $CFG->dirroot . "/$location/$plugin/lang/";
4584             }
4585         }
4586     }
4587
4588 /// First check all the normal locations for the string in the current language
4589     $resultstring = '';
4590     foreach ($locations as $location) {
4591         $locallangfile = $location.$lang.'_local'.'/'.$module.'.php';    //first, see if there's a local file
4592         if (file_exists($locallangfile)) {
4593             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4594                 eval($result);
4595                 return $resultstring;
4596             }
4597         }
4598         //if local directory not found, or particular string does not exist in local direcotry
4599         $langfile = $location.$lang.'/'.$module.'.php';
4600         if (file_exists($langfile)) {
4601             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4602                 eval($result);
4603                 return $resultstring;
4604             }
4605        }
4606     }
4607
4608 /// If the preferred language was English (utf8) we can abort now
4609 /// saving some checks beacuse it's the only "root" lang
4610     if ($lang == 'en_utf8') {
4611         return '[['. $identifier .']]';
4612     }
4613
4614 /// Is a parent language defined?  If so, try to find this string in a parent language file
4615
4616     foreach ($locations as $location) {
4617         $langfile = $location.$lang.'/'.$filetocheck;
4618         if (file_exists($langfile)) {
4619             if ($result = get_string_from_file('parentlanguage', $langfile, "\$parentlang")) {
4620                 eval($result);
4621                 if (!empty($parentlang)) {   // found it!
4622
4623                     //first, see if there's a local file for parent
4624                     $locallangfile = $location.$parentlang.'_local'.'/'.$module.'.php';
4625                     if (file_exists($locallangfile)) {
4626                         if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4627                             eval($result);
4628                             return $resultstring;
4629                         }
4630                     }
4631
4632                     //if local directory not found, or particular string does not exist in local direcotry
4633                     $langfile = $location.$parentlang.'/'.$module.'.php';
4634                     if (file_exists($langfile)) {
4635                         if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4636                             eval($result);
4637                             return $resultstring;
4638                         }
4639                     }
4640                 }
4641             }
4642         }
4643     }
4644
4645 /// Our only remaining option is to try English
4646
4647     foreach ($locations as $location) {
4648         $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4649         if (file_exists($locallangfile)) {
4650             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4651                 eval($result);
4652                 return $resultstring;
4653             }
4654         }
4655
4656         //if local_en not found, or string not found in local_en
4657         $langfile = $location.$defaultlang.'/'.$module.'.php';
4658
4659         if (file_exists($langfile)) {
4660             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4661                 eval($result);
4662                 return $resultstring;
4663             }
4664         }
4665     }
4666
4667 /// And, because under 1.6 en is defined as en_utf8 child, me must try
4668 /// if it hasn't been queried before.
4669     if ($defaultlang  == 'en') {
4670         $defaultlang = 'en_utf8';
4671         foreach ($locations as $location) {
4672             $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4673             if (file_exists($locallangfile)) {
4674                 if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4675                     eval($result);
4676                     return $resultstring;
4677                 }
4678             }
4679
4680             //if local_en not found, or string not found in local_en
4681             $langfile = $location.$defaultlang.'/'.$module.'.php';
4682
4683             if (file_exists($langfile)) {
4684                 if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4685                     eval($result);
4686                     return $resultstring;
4687                 }
4688             }
4689         }
4690     }
4691
4692     return '[['.$identifier.']]';  // Last resort
4693 }
4694
4695 /**
4696  * This function is only used from {@link get_string()}.
4697  *
4698  * @internal Only used from get_string, not meant to be public API
4699  * @param string $identifier ?
4700  * @param string $langfile ?
4701  * @param string $destination ?
4702  * @return string|false ?
4703  * @staticvar array $strings Localized strings
4704  * @access private
4705  * @todo Finish documenting this function.
4706  */
4707 function get_string_from_file($identifier, $langfile, $destination) {
4708
4709     static $strings;    // Keep the strings cached in memory.
4710
4711     if (empty($strings[$langfile])) {
4712         $string = array();
4713         include ($langfile);
4714         $strings[$langfile] = $string;
4715     } else {
4716         $string = &$strings[$langfile];
4717     }
4718
4719     if (!isset ($string[$identifier])) {
4720         return false;
4721     }
4722
4723     return $destination .'= sprintf("'. $string[$identifier] .'");';
4724 }
4725
4726 /**
4727  * Converts an array of strings to their localized value.
4728  *
4729  * @param array $array An array of strings
4730  * @param string $module The language module that these strings can be found in.
4731  * @return string
4732  */
4733 function get_strings($array, $module='') {
4734
4735    $string = NULL;
4736    foreach ($array as $item) {
4737        $string->$item = get_string($item, $module);
4738    }
4739    return $string;
4740 }
4741
4742 /**
4743  * Returns a list of language codes and their full names
4744  * hides the _local files from everyone.
4745  * @param bool refreshcache force refreshing of lang cache
4746  * @param bool returnall ignore langlist, return all languages available
4747  * @return array An associative array with contents in the form of LanguageCode => LanguageName
4748  */
4749 function get_list_of_languages($refreshcache=false, $returnall=false) {
4750
4751     global $CFG;
4752
4753     $languages = array();
4754
4755     $filetocheck = 'langconfig.php';
4756
4757     if (!$refreshcache && !$returnall && !empty($CFG->langcache) && file_exists($CFG->dataroot .'/cache/languages')) {
4758 /// read available langs from cache
4759
4760         $lines = file($CFG->dataroot .'/cache/languages');
4761         foreach ($lines as $line) {
4762             $line = trim($line);
4763             if (preg_match('/^(\w+)\s+(.+)/', $line, $matches)) {
4764                 $languages[$matches[1]] = $matches[2];
4765             }
4766         }
4767         unset($lines); unset($line); unset($matches);
4768         return $languages;
4769     }
4770
4771     if (!$returnall && !empty($CFG->langlist)) {
4772 /// return only languages allowed in langlist admin setting
4773
4774         $langlist = explode(',', $CFG->langlist);
4775         // fix short lang names first - non existing langs are skipped anyway...
4776         foreach ($langlist as $lang) {
4777             if (strpos($lang, '_utf8') === false) {
4778                 $langlist[] = $lang.'_utf8';
4779             }
4780         }
4781         // find existing langs from langlist
4782         foreach ($langlist as $lang) {
4783             $lang = trim($lang);   //Just trim spaces to be a bit more permissive
4784             if (strstr($lang, '_local')!==false) {
4785                 continue;
4786             }
4787             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4788                 $shortlang = substr($lang, 0, -5);
4789             } else {
4790                 $shortlang = $lang;
4791             }
4792         /// Search under dirroot/lang
4793             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4794                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4795                 if (!empty($string['thislanguage'])) {
4796                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4797                 }
4798                 unset($string);
4799             }
4800         /// And moodledata/lang
4801             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4802                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4803                 if (!empty($string['thislanguage'])) {
4804                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4805                 }
4806                 unset($string);
4807             }
4808         }
4809
4810     } else {
4811 /// return all languages available in system
4812     /// Fetch langs from moodle/lang directory
4813         $langdirs = get_list_of_plugins('lang');
4814     /// Fetch langs from moodledata/lang directory
4815         $langdirs2 = get_list_of_plugins('lang', '', $CFG->dataroot);
4816     /// Merge both lists of langs
4817         $langdirs = array_merge($langdirs, $langdirs2);
4818     /// Sort all
4819         asort($langdirs);
4820     /// Get some info from each lang (first from moodledata, then from moodle)
4821         foreach ($langdirs as $lang) {
4822             if (strstr($lang, '_local')!==false) {
4823                 continue;
4824             }
4825             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4826                 $shortlang = substr($lang, 0, -5);
4827             } else {
4828                 $shortlang = $lang;
4829             }
4830         /// Search under moodledata/lang
4831             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4832                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4833                 if (!empty($string['thislanguage'])) {
4834                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4835                 }
4836                 unset($string);
4837             }
4838         /// And dirroot/lang
4839             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4840                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4841                 if (!empty($string['thislanguage'])) {
4842                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4843                 }
4844                 unset($string);
4845             }
4846         }
4847     }
4848
4849     if ($refreshcache && !empty($CFG->langcache)) {
4850         if ($returnall) {
4851             // we have a list of all langs only, just delete old cache
4852             @unlink($CFG->dataroot.'/cache/languages');
4853
4854         } else {
4855             // store the list of allowed languages
4856             if ($file = fopen($CFG->dataroot .'/cache/languages', 'w')) {
4857                 foreach ($languages as $key => $value) {
4858                     fwrite($file, "$key $value\n");
4859                 }
4860                 fclose($file);
4861             }
4862         }
4863     }
4864
4865     return $languages;
4866 }
4867
4868 /**
4869  * Returns a list of charset codes. It's hardcoded, so they should be added manually
4870  * (cheking that such charset is supported by the texlib library!)
4871  *
4872  * @return array And associative array with contents in the form of charset => charset
4873  */
4874 function get_list_of_charsets() {
4875
4876     $charsets = array(
4877         'EUC-JP'     => 'EUC-JP',
4878         'ISO-2022-JP'=> 'ISO-2022-JP',
4879         'ISO-8859-1' => 'ISO-8859-1',
4880         'SHIFT-JIS'  => 'SHIFT-JIS',
4881         'GB2312'     => 'GB2312',
4882         'GB18030'    => 'GB18030', // gb18030 not supported by typo and mbstring
4883         'UTF-8'      => 'UTF-8');
4884
4885     asort($charsets);
4886
4887     return $charsets;
4888 }
4889
4890 /**
4891  * Returns a list of country names in the current language
4892  *
4893  * @uses $CFG
4894  * @uses $USER
4895  * @return array
4896  */
4897 function get_list_of_countries() {
4898     global $CFG, $USER;
4899
4900     $lang = current_language();
4901
4902     if (!file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php') &&
4903         !file_exists($CFG->dataroot.'/lang/'. $lang .'/countries.php')) {
4904         if ($parentlang = get_string('parentlanguage')) {
4905             if (file_exists($CFG->dirroot .'/lang/'. $parentlang .'/countries.php') ||
4906                 file_exists($CFG->dataroot.'/lang/'. $parentlang .'/countries.php')) {
4907                 $lang = $parentlang;
4908             } else {
4909                 $lang = 'en_utf8';  // countries.php must exist in this pack
4910             }
4911         } else {
4912             $lang = 'en_utf8';  // countries.php must exist in this pack
4913         }
4914     }
4915
4916     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/countries.php')) {
4917         include($CFG->dataroot .'/lang/'. $lang .'/countries.php');
4918     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php')) {
4919         include($CFG->dirroot .'/lang/'. $lang .'/countries.php');
4920     }
4921
4922     if (!empty($string)) {
4923         asort($string);
4924     }
4925
4926     return $string;
4927 }
4928
4929 /**
4930  * Returns a list of valid and compatible themes
4931  *
4932  * @uses $CFG
4933  * @return array
4934  */
4935 function get_list_of_themes() {
4936
4937     global $CFG;
4938
4939     $themes = array();
4940
4941     if (!empty($CFG->themelist)) {       // use admin's list of themes
4942         $themelist = explode(',', $CFG->themelist);
4943     } else {
4944         $themelist = get_list_of_plugins("theme");
4945     }
4946
4947     foreach ($themelist as $key => $theme) {
4948         if (!file_exists("$CFG->themedir/$theme/config.php")) {   // bad folder
4949             continue;
4950         }
4951         $THEME = new object();    // Note this is not the global one!!  :-)
4952         include("$CFG->themedir/$theme/config.php");
4953         if (!isset($THEME->sheets)) {   // Not a valid 1.5 theme
4954             continue;
4955         }
4956         $themes[$theme] = $theme;
4957     }
4958     asort($themes);
4959
4960     return $themes;
4961 }
4962
4963
4964 /**
4965  * Returns a list of picture names in the current or specified language
4966  *
4967  * @uses $CFG
4968  * @return array
4969  */
4970 function get_list_of_pixnames($lang = '') {
4971     global $CFG;
4972
4973     if (empty($lang)) {
4974         $lang = current_language();
4975     }
4976
4977     $string = array();
4978
4979     $path = $CFG->dirroot .'/lang/en_utf8/pix.php'; // always exists
4980
4981     if (file_exists($CFG->dataroot .'/lang/'. $lang .'_local/pix.php')) {
4982         $path = $CFG->dataroot .'/lang/'. $lang .'_local/pix.php';
4983
4984     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/pix.php')) {
4985         $path = $CFG->dirroot .'/lang/'. $lang .'/pix.php';
4986
4987     } else if (file_exists($CFG->dataroot .'/lang/'. $lang .'/pix.php')) {
4988         $path = $CFG->dataroot .'/lang/'. $lang .'/pix.php';
4989
4990     } else if ($parentlang = get_string('parentlanguage') and $parentlang != '[[parentlanguage]]') {
4991         return get_list_of_pixnames($parentlang); //return pixnames from parent language instead
4992     }
4993
4994     include($path);
4995
4996     return $string;
4997 }
4998
4999 /**
5000  * Returns a list of timezones in the current language
5001  *
5002  * @uses $CFG
5003  * @return array
5004  */
5005 function get_list_of_timezones() {
5006     global $CFG;
5007
5008     static $timezones;
5009
5010     if (!empty($timezones)) {    // This function has been called recently
5011         return $timezones;
5012     }
5013
5014     $timezones = array();
5015
5016     if ($rawtimezones = get_records_sql('SELECT MAX(id), name FROM '.$CFG->prefix.'timezone GROUP BY name')) {
5017         foreach($rawtimezones as $timezone) {
5018             if (!empty($timezone->name)) {
5019                 $timezones[$timezone->name] = get_string(strtolower($timezone->name), 'timezones');
5020                 if (substr($timezones[$timezone->name], 0, 1) == '[') {  // No translation found
5021                     $timezones[$timezone->name] = $timezone->name;
5022                 }
5023             }
5024         }
5025     }
5026
5027     asort($timezones);
5028
5029     for ($i = -13; $i <= 13; $i += .5) {
5030         $tzstring = 'GMT';
5031         if ($i < 0) {
5032             $timezones[sprintf("%.1f", $i)] = $tzstring . $i;
5033         } else if ($i > 0) {
5034             $timezones[sprintf("%.1f", $i)] = $tzstring . '+' . $i;
5035         } else {
5036             $timezones[sprintf("%.1f", $i)] = $tzstring;
5037         }
5038     }
5039
5040     return $timezones;
5041 }
5042
5043 /**
5044  * Returns a list of currencies in the current language
5045  *
5046  * @uses $CFG
5047  * @uses $USER
5048  * @return array
5049  */
5050 function get_list_of_currencies() {
5051     global $CFG, $USER;
5052
5053     $lang = current_language();
5054
5055     if (!file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5056         if ($parentlang = get_string('parentlanguage')) {
5057             if (file_exists($CFG->dataroot .'/lang/'. $parentlang .'/currencies.php')) {
5058                 $lang = $parentlang;
5059             } else {
5060                 $lang = 'en_utf8';  // currencies.php must exist in this pack
5061             }
5062         } else {
5063             $lang = 'en_utf8';  // currencies.php must exist in this pack
5064         }
5065     }
5066
5067     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5068         include_once($CFG->dataroot .'/lang/'. $lang .'/currencies.php');
5069     } else {    //if en_utf8 is not installed in dataroot
5070         include_once($CFG->dirroot .'/lang/'. $lang .'/currencies.php');
5071     }
5072
5073     if (!empty($string)) {
5074         asort($string);
5075     }
5076
5077     return $string;
5078 }
5079
5080
5081
5082 /**
5083  * Can include a given document file (depends on second
5084  * parameter) or just return info about it.
5085  *
5086  * @uses $CFG
5087  * @param string $file ?
5088  * @param bool $include ?
5089  * @return ?
5090  * @todo Finish documenting this function
5091  */
5092 function document_file($file, $include=true) {
5093     global $CFG;
5094
5095     $file = clean_filename($file);
5096
5097     if (empty($file)) {
5098         return false;
5099     }
5100
5101     $langs = array(current_language(), get_string('parentlanguage'), 'en');
5102
5103     foreach ($langs as $lang) {
5104         $info = new object();
5105         $info->filepath = $CFG->dirroot .'/lang/'. $lang .'/docs/'. $file;
5106         $info->urlpath  = $CFG->wwwroot .'/lang/'. $lang .'/docs/'. $file;
5107
5108         if (file_exists($info->filepath)) {
5109             if ($include) {
5110                 include($info->filepath);
5111             }
5112             return $info;
5113         }
5114     }
5115
5116     return false;
5117 }
5118
5119 /// ENCRYPTION  ////////////////////////////////////////////////
5120
5121 /**
5122  * rc4encrypt
5123  *
5124  * @param string $data ?
5125  * @return string
5126  * @todo Finish documenting this function
5127  */
5128 function rc4encrypt($data) {
5129     $password = 'nfgjeingjk';
5130     return endecrypt($password, $data, '');
5131 }
5132
5133 /**
5134  * rc4decrypt
5135  *
5136  * @param string $data ?
5137  * @return string
5138  * @todo Finish documenting this function
5139  */
5140 function rc4decrypt($data) {
5141     $password = 'nfgjeingjk';
5142     return endecrypt($password, $data, 'de');
5143 }
5144
5145 /**
5146  * Based on a class by Mukul Sabharwal [mukulsabharwal @ yahoo.com]
5147  *
5148  * @param string $pwd ?
5149  * @param string $data ?
5150  * @param string $case ?
5151  * @return string
5152  * @todo Finish documenting this function
5153  */
5154 function endecrypt ($pwd, $data, $case) {
5155
5156     if ($case == 'de') {
5157         $data = urldecode($data);
5158     }
5159
5160     $key[] = '';
5161     $box[] = '';
5162     $temp_swap = '';
5163     $pwd_length = 0;
5164
5165     $pwd_length = strlen($pwd);
5166
5167     for ($i = 0; $i <= 255; $i++) {
5168         $key[$i] = ord(substr($pwd, ($i % $pwd_length), 1));
5169         $box[$i] = $i;
5170     }
5171
5172     $x = 0;
5173
5174     for ($i = 0; $i <= 255; $i++) {
5175         $x = ($x + $box[$i] + $key[$i]) % 256;
5176         $temp_swap = $box[$i];
5177         $box[$i] = $box[$x];
5178         $box[$x] = $temp_swap;
5179     }
5180
5181     $temp = '';
5182     $k = '';
5183
5184     $cipherby = '';
5185     $cipher = '';
5186
5187     $a = 0;
5188     $j = 0;
5189
5190     for ($i = 0; $i < strlen($data); $i++) {
5191         $a = ($a + 1) % 256;
5192         $j = ($j + $box[$a]) % 256;
5193         $temp = $box[$a];
5194         $box[$a] = $box[$j];
5195         $box[$j] = $temp;
5196         $k = $box[(($box[$a] + $box[$j]) % 256)];
5197         $cipherby = ord(substr($data, $i, 1)) ^ $k;
5198         $cipher .= chr($cipherby);
5199     }
5200
5201     if ($case == 'de') {
5202         $cipher = urldecode(urlencode($cipher));
5203     } else {
5204         $cipher = urlencode($cipher);
5205     }
5206
5207     return $cipher;
5208 }
5209
5210
5211 /// CALENDAR MANAGEMENT  ////////////////////////////////////////////////////////////////
5212
5213
5214 /**
5215  * Call this function to add an event to the calendar table
5216  *  and to call any calendar plugins
5217  *
5218  * @uses $CFG
5219  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field. The object event should include the following:
5220  *  <ul>
5221  *    <li><b>$event->name</b> - Name for the event
5222  *    <li><b>$event->description</b> - Description of the event (defaults to '')
5223  *    <li><b>$event->format</b> - Format for the description (using formatting types defined at the top of weblib.php)
5224  *    <li><b>$event->courseid</b> - The id of the course this event belongs to (0 = all courses)
5225  *    <li><b>$event->groupid</b> - The id of the group this event belongs to (0 = no group)
5226  *    <li><b>$event->userid</b> - The id of the user this event belongs to (0 = no user)
5227  *    <li><b>$event->modulename</b> - Name of the module that creates this event
5228  *    <li><b>$event->instance</b> - Instance of the module that owns this event
5229  *    <li><b>$event->eventtype</b> - The type info together with the module info could
5230  *             be used by calendar plugins to decide how to display event
5231  *    <li><b>$event->timestart</b>- Timestamp for start of event
5232  *    <li><b>$event->timeduration</b> - Duration (defaults to zero)
5233  *    <li><b>$event->visible</b> - 0 if the event should be hidden (e.g. because the activity that created it is hidden)
5234  *  </ul>
5235  * @return int The id number of the resulting record
5236  */
5237  function add_event($event) {
5238
5239     global $CFG;
5240
5241     $event->timemodified = time();
5242
5243     if (!$event->id = insert_record('event', $event)) {
5244         return false;
5245     }
5246
5247     if (!empty($CFG->calendar)) { // call the add_event function of the selected calendar
5248         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5249             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5250             $calendar_add_event = $CFG->calendar.'_add_event';
5251             if (function_exists($calendar_add_event)) {
5252                 $calendar_add_event($event);
5253             }
5254         }
5255     }
5256
5257     return $event->id;
5258 }
5259
5260 /**
5261  * Call this function to update an event in the calendar table
5262  * the event will be identified by the id field of the $event object.
5263  *
5264  * @uses $CFG
5265  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5266  * @return bool
5267  */
5268 function update_event($event) {
5269
5270     global $CFG;
5271
5272     $event->timemodified = time();
5273
5274     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5275         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5276             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5277             $calendar_update_event = $CFG->calendar.'_update_event';
5278             if (function_exists($calendar_update_event)) {
5279                 $calendar_update_event($event);
5280             }
5281         }
5282     }
5283     return update_record('event', $event);
5284 }
5285
5286 /**
5287  * Call this function to delete the event with id $id from calendar table.
5288  *
5289  * @uses $CFG
5290  * @param int $id The id of an event from the 'calendar' table.
5291  * @return array An associative array with the results from the SQL call.
5292  * @todo Verify return type
5293  */
5294 function delete_event($id) {
5295
5296     global $CFG;
5297
5298     if (!empty($CFG->calendar)) { // call the delete_event function of the selected calendar
5299         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5300             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5301             $calendar_delete_event = $CFG->calendar.'_delete_event';
5302             if (function_exists($calendar_delete_event)) {
5303                 $calendar_delete_event($id);
5304             }
5305         }
5306     }
5307     return delete_records('event', 'id', $id);
5308 }
5309
5310 /**
5311  * Call this function to hide an event in the calendar table
5312  * the event will be identified by the id field of the $event object.
5313  *
5314  * @uses $CFG
5315  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5316  * @return array An associative array with the results from the SQL call.
5317  * @todo Verify return type
5318  */
5319 function hide_event($event) {
5320     global $CFG;
5321
5322     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5323         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5324             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5325             $calendar_hide_event = $CFG->calendar.'_hide_event';
5326             if (function_exists($calendar_hide_event)) {
5327                 $calendar_hide_event($event);
5328             }
5329         }
5330     }
5331     return set_field('event', 'visible', 0, 'id', $event->id);
5332 }
5333
5334 /**
5335  * Call this function to unhide an event in the calendar table
5336  * the event will be identified by the id field of the $event object.
5337  *
5338  * @uses $CFG
5339  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5340  * @return array An associative array with the results from the SQL call.
5341  * @todo Verify return type
5342  */
5343 function show_event($event) {
5344     global $CFG;
5345
5346     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5347         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5348             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5349             $calendar_show_event = $CFG->calendar.'_show_event';
5350             if (function_exists($calendar_show_event)) {
5351                 $calendar_show_event($event);
5352             }
5353         }
5354     }
5355     return set_field('event', 'visible', 1, 'id', $event->id);
5356 }
5357
5358
5359 /// ENVIRONMENT CHECKING  ////////////////////////////////////////////////////////////
5360
5361 /**
5362  * Lists plugin directories within some directory
5363  *
5364  * @uses $CFG
5365  * @param string $plugin dir under we'll look for plugins (defaults to 'mod')
5366  * @param string $exclude dir name to exclude from the list (defaults to none)
5367  * @param string $basedir full path to the base dir where $plugin resides (defaults to $CFG->dirroot)
5368  * @return array of plugins found under the requested parameters
5369  */
5370 function get_list_of_plugins($plugin='mod', $exclude='', $basedir='') {
5371
5372     global $CFG;
5373
5374     $plugins = array();
5375
5376     if (empty($basedir)) {
5377
5378         # This switch allows us to use the appropiate theme directory - and potentialy alternatives for other plugins
5379         switch ($plugin) {
5380         case "theme":
5381             $basedir = $CFG->themedir;
5382             break;
5383
5384         default:
5385             $basedir = $CFG->dirroot .'/'. $plugin;
5386         }
5387
5388     } else {
5389         $basedir = $basedir .'/'. $plugin;
5390     }
5391
5392     if (file_exists($basedir) && filetype($basedir) == 'dir') {
5393         $dirhandle = opendir($basedir);
5394         while (false !== ($dir = readdir($dirhandle))) {
5395             $firstchar = substr($dir, 0, 1);
5396             if ($firstchar == '.' or $dir == 'CVS' or $dir == '_vti_cnf' or $dir == $exclude) {
5397                 continue;
5398             }
5399             if (filetype($basedir .'/'. $dir) != 'dir') {
5400                 continue;
5401             }
5402             $plugins[] = $dir;
5403         }
5404         closedir($dirhandle);
5405     }
5406     if ($plugins) {
5407         asort($plugins);
5408     }
5409     return $plugins;
5410 }
5411
5412 /**
5413  * Returns true if the current version of PHP is greater that the specified one.
5414  *
5415  * @param string $version The version of php being tested.
5416  * @return bool
5417  */
5418 function check_php_version($version='4.1.0') {
5419     return (version_compare(phpversion(), $version) >= 0);
5420 }
5421
5422
5423 /**
5424  * Checks to see if is a browser matches the specified
5425  * brand and is equal or better version.
5426  *
5427  * @uses $_SERVER
5428  * @param string $brand The browser identifier being tested
5429  * @param int $version The version of the browser
5430  * @return bool true if the given version is below that of the detected browser
5431  */
5432  function check_browser_version($brand='MSIE', $version=5.5) {
5433     if (empty($_SERVER['HTTP_USER_AGENT'])) {
5434         return false;
5435     }
5436
5437     $agent = $_SERVER['HTTP_USER_AGENT'];
5438
5439     switch ($brand) {
5440
5441       case 'Camino':   /// Mozilla Firefox browsers
5442
5443               if (preg_match("/Camino\/([0-9\.]+)/i", $agent, $match)) {
5444                   if (version_compare($match[1], $version) >= 0) {
5445                       return true;
5446                   }
5447               }
5448               break;
5449
5450
5451       case 'Firefox':   /// Mozilla Firefox browsers
5452
5453           if (preg_match("/Firefox\/([0-9\.]+)/i", $agent, $match)) {
5454               if (version_compare($match[1], $version) >= 0) {
5455                   return true;
5456               }
5457           }
5458           break;
5459
5460
5461       case 'Gecko':   /// Gecko based browsers
5462
5463           if (substr_count($agent, 'Camino')) {
5464               // MacOS X Camino support
5465               $version = 20041110;
5466           }
5467
5468           // the proper string - Gecko/CCYYMMDD Vendor/Version
5469           // Faster version and work-a-round No IDN problem.
5470           if (preg_match("/Gecko\/([0-9]+)/i", $agent, $match)) {
5471               if ($match[1] > $version) {
5472                       return true;
5473                   }
5474               }
5475           break;
5476
5477
5478       case 'MSIE':   /// Internet Explorer
5479
5480           if (strpos($agent, 'Opera')) {     // Reject Opera
5481               return false;
5482           }
5483           $string = explode(';', $agent);
5484           if (!isset($string[1])) {
5485               return false;
5486           }
5487           $string = explode(' ', trim($string[1]));
5488           if (!isset($string[0]) and !isset($string[1])) {
5489               return false;
5490           }
5491           if ($string[0] == $brand and (float)$string[1] >= $version ) {
5492               return true;
5493           }
5494           break;
5495
5496       case 'Opera':  /// Opera
5497
5498           if (preg_match("/Opera\/([0-9\.]+)/i", $agent, $match)) {
5499               if (version_compare($match[1], $version) >= 0) {
5500                   return true;
5501               }
5502           }
5503           break;
5504
5505       case 'Safari':  /// Safari
5506           // Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SimbianOS
5507           if (strpos($agent, 'OmniWeb')) { // Reject OmniWeb
5508               return false;
5509           } elseif (strpos($agent, 'Shiira')) { // Reject Shiira
5510               return false;
5511           } elseif (strpos($agent, 'SimbianOS')) { // Reject SimbianOS
5512               return false;
5513           }
5514
5515           if (preg_match("/AppleWebKit\/([0-9]+)/i", $agent, $match)) {
5516               if (version_compare($match[1], $version) >= 0) {
5517                   return true;
5518               }
5519           }
5520
5521           break;
5522
5523     }
5524
5525     return false;
5526 }
5527
5528 /**
5529  * This function makes the return value of ini_get consistent if you are
5530  * setting server directives through the .htaccess file in apache.
5531  * Current behavior for value set from php.ini On = 1, Off = [blank]
5532  * Current behavior for value set from .htaccess On = On, Off = Off
5533  * Contributed by jdell @ unr.edu
5534  *
5535  * @param string $ini_get_arg ?
5536  * @return bool
5537  * @todo Finish documenting this function
5538  */
5539 function ini_get_bool($ini_get_arg) {
5540     $temp = ini_get($ini_get_arg);
5541
5542     if ($temp == '1' or strtolower($temp) == 'on') {
5543         return true;
5544     }
5545     return false;
5546 }
5547
5548 /**
5549  * Compatibility stub to provide backward compatibility
5550  *
5551  * Determines if the HTML editor is enabled.
5552  * @deprecated Use {@link can_use_html_editor()} instead.
5553  */
5554  function can_use_richtext_editor() {
5555     return can_use_html_editor();
5556 }
5557
5558 /**
5559  * Determines if the HTML editor is enabled.
5560  *
5561  * This depends on site and user
5562  * settings, as well as the current browser being used.
5563  *
5564  * @return string|false Returns false if editor is not being used, otherwise
5565  * returns 'MSIE' or 'Gecko'.
5566  */
5567  function can_use_html_editor() {
5568     global $USER, $CFG;
5569
5570     if (!empty($USER->htmleditor) and !empty($CFG->htmleditor)) {
5571         if (check_browser_version('MSIE', 5.5)) {
5572             return 'MSIE';
5573         } else if (check_browser_version('Gecko', 20030516)) {
5574             return 'Gecko';
5575         }
5576     }
5577     return false;
5578 }
5579
5580 /**
5581  * Hack to find out the GD version by parsing phpinfo output
5582  *
5583  * @return int GD version (1, 2, or 0)
5584  */
5585 function check_gd_version() {
5586     $gdversion = 0;
5587
5588     if (function_exists('gd_info')){
5589         $gd_info = gd_info();
5590         if (substr_count($gd_info['GD Version'], '2.')) {
5591             $gdversion = 2;
5592         } else if (substr_count($gd_info['GD Version'], '1.')) {
5593             $gdversion = 1;
5594         }
5595
5596     } else {
5597         ob_start();
5598         phpinfo(8);
5599         $phpinfo = ob_get_contents();
5600         ob_end_clean();
5601
5602         $phpinfo = explode("\n", $phpinfo);
5603
5604
5605         foreach ($phpinfo as $text) {
5606             $parts = explode('</td>', $text);
5607             foreach ($parts as $key => $val) {
5608                 $parts[$key] = trim(strip_tags($val));
5609             }
5610             if ($parts[0] == 'GD Version') {
5611                 if (substr_count($parts[1], '2.0')) {
5612                     $parts[1] = '2.0';
5613                 }
5614                 $gdversion = intval($parts[1]);
5615             }
5616         }
5617     }
5618
5619     return $gdversion;   // 1, 2 or 0
5620 }
5621
5622 /**
5623  * Determine if moodle installation requires update
5624  *
5625  * Checks version numbers of main code and all modules to see
5626  * if there are any mismatches
5627  *
5628  * @uses $CFG
5629  * @return bool
5630  */
5631 function moodle_needs_upgrading() {
5632     global $CFG;
5633
5634     $version = null;
5635     include_once($CFG->dirroot .'/version.php');  # defines $version and upgrades
5636     if ($CFG->version) {
5637         if ($version > $CFG->version) {
5638             return true;
5639         }
5640         if ($mods = get_list_of_plugins('mod')) {
5641             foreach ($mods as $mod) {
5642                 $fullmod = $CFG->dirroot .'/mod/'. $mod;
5643                 $module = new object();
5644                 if (!is_readable($fullmod .'/version.php')) {
5645                     notify('Module "'. $mod .'" is not readable - check permissions');
5646                     continue;
5647                 }
5648                 include_once($fullmod .'/version.php');  # defines $module with version etc
5649                 if ($currmodule = get_record('modules', 'name', $mod)) {
5650                     if ($module->version > $currmodule->version) {
5651                         return true;
5652                     }
5653                 }
5654             }
5655         }
5656     } else {
5657         return true;
5658     }
5659     return false;
5660 }
5661
5662
5663 /// MISCELLANEOUS ////////////////////////////////////////////////////////////////////
5664
5665 /**
5666  * Notify admin users or admin user of any failed logins (since last notification).
5667  *
5668  * @uses $CFG
5669  * @uses $db
5670  * @uses HOURSECS
5671  */
5672 function notify_login_failures() {
5673     global $CFG, $db;
5674
5675     switch ($CFG->notifyloginfailures) {
5676         case 'mainadmin' :
5677             $recip = array(get_admin());
5678             break;
5679         case 'alladmins':
5680             $recip = get_admins();
5681             break;
5682     }
5683
5684     if (empty($CFG->lastnotifyfailure)) {
5685         $CFG->lastnotifyfailure=0;
5686     }
5687
5688     // we need to deal with the threshold stuff first.
5689     if (empty($CFG->notifyloginthreshold)) {
5690         $CFG->notifyloginthreshold = 10; // default to something sensible.
5691     }
5692
5693     $notifyipsrs = $db->Execute('SELECT ip FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5694                           AND module=\'login\' AND action=\'error\' GROUP BY ip HAVING count(*) > '. $CFG->notifyloginthreshold);
5695
5696     $notifyusersrs = $db->Execute('SELECT info FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5697                           AND module=\'login\' AND action=\'error\' GROUP BY info HAVING count(*) > '. $CFG->notifyloginthreshold);
5698
5699     if ($notifyipsrs) {
5700         $ipstr = '';
5701         while ($row = rs_fetch_next_record($notifyipsrs)) {
5702             $ipstr .= "'". $row->ip ."',";
5703         }
5704         rs_close($notifyipsrs);
5705         $ipstr = substr($ipstr,0,strlen($ipstr)-1);
5706     }
5707     if ($notifyusersrs) {
5708         $userstr = '';
5709         while ($row = rs_fetch_next_record($notifyusersrs)) {
5710             $userstr .= "'". $row->info ."',";
5711         }
5712         rs_close($notifyusersrs);
5713         $userstr = substr($userstr,0,strlen($userstr)-1);
5714     }
5715
5716     if (strlen($userstr) > 0 || strlen($ipstr) > 0) {
5717         $count = 0;
5718         $logs = get_logs('time > '. $CFG->lastnotifyfailure .' AND module=\'login\' AND action=\'error\' '
5719                  .((strlen($ipstr) > 0 && strlen($userstr) > 0) ? ' AND ( ip IN ('. $ipstr .') OR info IN ('. $userstr .') ) '
5720                  : ((strlen($ipstr) != 0) ? ' AND ip IN ('. $ipstr .') ' : ' AND info IN ('. $userstr .') ')), 'l.time DESC', '', '', $count);
5721
5722         // if we haven't run in the last hour and we have something useful to report and we are actually supposed to be reporting to somebody
5723         if (is_array($recip) and count($recip) > 0 and ((time() - HOURSECS) > $CFG->lastnotifyfailure)
5724             and is_array($logs) and count($logs) > 0) {
5725
5726             $message = '';
5727             $site = get_site();
5728             $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));
5729             $message .= get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot)
5730                  .(($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n";
5731             foreach ($logs as $log) {
5732                 $log->time = userdate($log->time);
5733                 $message .= get_string('notifyloginfailuresmessage','',$log)."\n";
5734             }
5735             $message .= "\n\n".get_string('notifyloginfailuresmessageend','',$CFG->wwwroot)."\n\n";
5736             foreach ($recip as $admin) {
5737                 mtrace('Emailing '. $admin->username .' about '. count($logs) .' failed login attempts');
5738                 email_to_user($admin,get_admin(),$subject,$message);
5739             }
5740             $conf = new object();
5741             $conf->name = 'lastnotifyfailure';
5742             $conf->value = time();
5743             if ($current = get_record('config', 'name', 'lastnotifyfailure')) {
5744                 $conf->id = $current->id;
5745                 if (! update_record('config', $conf)) {
5746                     mtrace('Could not update last notify time');
5747                 }
5748
5749             } else if (! insert_record('config', $conf)) {
5750                 mtrace('Could not set last notify time');
5751             }
5752         }
5753     }
5754 }
5755
5756 /**
5757  * moodle_setlocale
5758  *
5759  * @uses $CFG
5760  * @param string $locale ?
5761  * @todo Finish documenting this function
5762  */
5763 function moodle_setlocale($locale='') {
5764
5765     global $CFG;
5766
5767     static $currentlocale = ''; // last locale caching
5768
5769     $oldlocale = $currentlocale;
5770
5771 /// Fetch the correct locale based on ostype
5772     if($CFG->ostype == 'WINDOWS') {
5773         $stringtofetch = 'localewin';
5774     } else {
5775         $stringtofetch = 'locale';
5776     }
5777
5778 /// the priority is the same as in get_string() - parameter, config, course, session, user, global language
5779     if (!empty($locale)) {
5780         $currentlocale = $locale;
5781     } else if (!empty($CFG->locale)) { // override locale for all language packs
5782         $currentlocale = $CFG->locale;
5783     } else {
5784         $currentlocale = get_string($stringtofetch);
5785     }
5786
5787 /// do nothing if locale already set up
5788     if ($oldlocale == $currentlocale) {
5789         return;
5790     }
5791
5792 /// Due to some strange BUG we cannot set the LC_TIME directly, so we fetch current values,
5793 /// set LC_ALL and then set values again. Just wondering why we cannot set LC_ALL only??? - stronk7
5794 /// Some day, numeric, monetary and other categories should be set too, I think. :-/
5795
5796 /// Get current values
5797     $monetary= setlocale (LC_MONETARY, 0);
5798     $numeric = setlocale (LC_NUMERIC, 0);
5799     $ctype   = setlocale (LC_CTYPE, 0);
5800     if ($CFG->ostype != 'WINDOWS') {
5801         $messages= setlocale (LC_MESSAGES, 0);
5802     }
5803 /// Set locale to all
5804     setlocale (LC_ALL, $currentlocale);
5805 /// Set old values
5806     setlocale (LC_MONETARY, $monetary);
5807     setlocale (LC_NUMERIC, $numeric);
5808     if ($CFG->ostype != 'WINDOWS') {
5809         setlocale (LC_MESSAGES, $messages);
5810     }
5811     if ($currentlocale == 'tr_TR' or $currentlocale == 'tr_TR.UTF-8') { // To workaround a well-known PHP problem with Turkish letter Ii
5812         setlocale (LC_CTYPE, $ctype);
5813     }
5814 }
5815
5816 /**
5817  * Converts string to lowercase using most compatible function available.
5818  *
5819  * @param string $string The string to convert to all lowercase characters.
5820  * @param string $encoding The encoding on the string.
5821  * @return string
5822  * @todo Add examples of calling this function with/without encoding types
5823  * @deprecated Use textlib->strtolower($text) instead.
5824  */
5825 function moodle_strtolower ($string, $encoding='') {
5826
5827     //If not specified use utf8
5828     if (empty($encoding)) {
5829         $encoding = 'UTF-8';
5830     }
5831     //Use text services
5832     $textlib = textlib_get_instance();
5833
5834     return $textlib->strtolower($string, $encoding);
5835 }
5836
5837 /**
5838  * Count words in a string.
5839  *
5840  * Words are defined as things between whitespace.
5841  *
5842  * @param string $string The text to be searched for words.
5843  * @return int The count of words in the specified string
5844  */
5845 function count_words($string) {
5846     $string = strip_tags($string);
5847     return count(preg_split("/\w\b/", $string)) - 1;
5848 }
5849
5850 /** Count letters in a string.
5851  *
5852  * Letters are defined as chars not in tags and different from whitespace.
5853  *
5854  * @param string $string The text to be searched for letters.
5855  * @return int The count of letters in the specified text.
5856  */
5857 function count_letters($string) {
5858 /// Loading the textlib singleton instance. We are going to need it.
5859     $textlib = textlib_get_instance();
5860
5861     $string = strip_tags($string); // Tags are out now
5862     $string = ereg_replace('[[:space:]]*','',$string); //Whitespace are out now
5863
5864     return $textlib->strlen($string);
5865 }
5866
5867 /**
5868  * Generate and return a random string of the specified length.
5869  *
5870  * @param int $length The length of the string to be created.
5871  * @return string
5872  */
5873 function random_string ($length=15) {
5874     $pool  = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
5875     $pool .= 'abcdefghijklmnopqrstuvwxyz';
5876     $pool .= '0123456789';
5877     $poollen = strlen($pool);
5878     mt_srand ((double) microtime() * 1000000);
5879     $string = '';
5880     for ($i = 0; $i < $length; $i++) {
5881         $string .= substr($pool, (mt_rand()%($poollen)), 1);
5882     }
5883     return $string;
5884 }
5885
5886 /*
5887  * Given some text (which may contain HTML) and an ideal length,
5888  * this function truncates the text neatly on a word boundary if possible
5889  */
5890 function shorten_text($text, $ideal=30) {
5891
5892    global $CFG;
5893
5894
5895    $i = 0;
5896    $tag = false;
5897    $length = strlen($text);
5898    $count = 0;
5899    $stopzone = false;
5900    $truncate = 0;
5901
5902    if ($length <= $ideal) {
5903        return $text;
5904    }
5905
5906    for ($i=0; $i<$length; $i++) {
5907        $char = $text[$i];
5908
5909        switch ($char) {
5910            case "<":
5911                $tag = true;
5912                break;
5913            case ">":
5914                $tag = false;
5915                break;
5916            default:
5917                if (!$tag) {
5918                    if ($stopzone) {
5919                        if ($char == '.' or $char == ' ') {
5920                            $truncate = $i+1;
5921                            break 2;
5922                        } else if (ord($char) >= 0xE0) {  // Chinese/Japanese/Korean text
5923                            $truncate = $i;               // can be truncated at any UTF-8
5924                            break 2;                      // character boundary.
5925                        }
5926                    }
5927                    $count++;
5928                }
5929                break;
5930        }
5931        if (!$stopzone) {
5932            if ($count > $ideal) {
5933                $stopzone = true;
5934            }
5935        }
5936    }
5937
5938    if (!$truncate) {
5939        $truncate = $i;
5940    }
5941
5942    $ellipse = ($truncate < $length) ? '...' : '';
5943
5944    return substr($text, 0, $truncate).$ellipse;
5945 }
5946
5947
5948 /**
5949  * Given dates in seconds, how many weeks is the date from startdate
5950  * The first week is 1, the second 2 etc ...
5951  *
5952  * @uses WEEKSECS
5953  * @param ? $startdate ?
5954  * @param ? $thedate ?
5955  * @return string
5956  * @todo Finish documenting this function
5957  */
5958 function getweek ($startdate, $thedate) {
5959     if ($thedate < $startdate) {   // error
5960         return 0;
5961     }
5962
5963     return floor(($thedate - $startdate) / WEEKSECS) + 1;
5964 }
5965
5966 /**
5967  * returns a randomly generated password of length $maxlen.  inspired by
5968  * {@link http://www.phpbuilder.com/columns/jesus19990502.php3}
5969  *
5970  * @param int $maxlength  The maximum size of the password being generated.
5971  * @return string
5972  */
5973 function generate_password($maxlen=10) {
5974     global $CFG;
5975
5976     $fillers = '1234567890!$-+';
5977     $wordlist = file($CFG->wordlist);
5978
5979     srand((double) microtime() * 1000000);
5980     $word1 = trim($wordlist[rand(0, count($wordlist) - 1)]);
5981     $word2 = trim($wordlist[rand(0, count($wordlist) - 1)]);
5982     $filler1 = $fillers[rand(0, strlen($fillers) - 1)];
5983
5984     return substr($word1 . $filler1 . $word2, 0, $maxlen);
5985 }
5986
5987 /**
5988  * Given a float, prints it nicely.
5989  * Do NOT use the result in any calculation later!
5990  *
5991  * @param float $flaot The float to print
5992  * @param int $places The number of decimal places to print.
5993  * @return string locale float
5994  */
5995 function format_float($float, $decimalpoints=1) {
5996     if (is_null($float)) {
5997         return '';
5998     }
5999     return number_format($float, $decimalpoints, get_string('decsep'), '');
6000 }
6001
6002 /**
6003  * Converts locale specific floating point/comma number back to standard PHP float value
6004  * Do NOT try to do any math operations before this conversion on any user submitted floats!
6005  *
6006  * @param  string $locale_float locale aware float representation
6007  */
6008 function unformat_float($locale_float) {
6009     $locale_float = trim($locale_float);
6010
6011     if ($locale_float == '') {
6012         return null;
6013     }
6014
6015     $locale_float = str_replace(' ', '', $locale_float); // no spaces - those might be used as thousand separators
6016
6017     return (float)str_replace(get_string('decsep'), '.', $locale_float);
6018 }
6019
6020 /**
6021  * Given a simple array, this shuffles it up just like shuffle()
6022  * Unlike PHP's shuffle() this function works on any machine.
6023  *
6024  * @param array $array The array to be rearranged
6025  * @return array
6026  */
6027 function swapshuffle($array) {
6028
6029     srand ((double) microtime() * 10000000);
6030     $last = count($array) - 1;
6031     for ($i=0;$i<=$last;$i++) {
6032         $from = rand(0,$last);
6033         $curr = $array[$i];
6034         $array[$i] = $array[$from];
6035         $array[$from] = $curr;
6036     }
6037     return $array;
6038 }
6039
6040 /**
6041  * Like {@link swapshuffle()}, but works on associative arrays
6042  *
6043  * @param array $array The associative array to be rearranged
6044  * @return array
6045  */
6046 function swapshuffle_assoc($array) {
6047 ///
6048
6049     $newkeys = swapshuffle(array_keys($array));
6050     foreach ($newkeys as $newkey) {
6051         $newarray[$newkey] = $array[$newkey];
6052     }
6053     return $newarray;
6054 }
6055
6056 /**
6057  * Given an arbitrary array, and a number of draws,
6058  * this function returns an array with that amount
6059  * of items.  The indexes are retained.
6060  *
6061  * @param array $array ?
6062  * @param ? $draws ?
6063  * @return ?
6064  * @todo Finish documenting this function
6065  */
6066 function draw_rand_array($array, $draws) {
6067     srand ((double) microtime() * 10000000);
6068
6069     $return = array();
6070
6071     $last = count($array);
6072
6073     if ($draws > $last) {
6074         $draws = $last;
6075     }
6076
6077     while ($draws > 0) {
6078         $last--;
6079
6080         $keys = array_keys($array);
6081         $rand = rand(0, $last);
6082
6083         $return[$keys[$rand]] = $array[$keys[$rand]];
6084         unset($array[$keys[$rand]]);
6085
6086         $draws--;
6087     }
6088
6089     return $return;
6090 }
6091
6092 /**
6093  * microtime_diff
6094  *
6095  * @param string $a ?
6096  * @param string $b ?
6097  * @return string
6098  * @todo Finish documenting this function
6099  */
6100 function microtime_diff($a, $b) {
6101     list($a_dec, $a_sec) = explode(' ', $a);
6102     list($b_dec, $b_sec) = explode(' ', $b);
6103     return $b_sec - $a_sec + $b_dec - $a_dec;
6104 }
6105
6106 /**
6107  * Given a list (eg a,b,c,d,e) this function returns
6108  * an array of 1->a, 2->b, 3->c etc
6109  *
6110  * @param array $list ?
6111  * @param string $separator ?
6112  * @todo Finish documenting this function
6113  */
6114 function make_menu_from_list($list, $separator=',') {
6115
6116     $array = array_reverse(explode($separator, $list), true);
6117     foreach ($array as $key => $item) {
6118         $outarray[$key+1] = trim($item);
6119     }
6120     return $outarray;
6121 }
6122
6123 /**
6124  * Creates an array that represents all the current grades that
6125  * can be chosen using the given grading type.  Negative numbers
6126  * are scales, zero is no grade, and positive numbers are maximum
6127  * grades.
6128  *
6129  * @param int $gradingtype ?
6130  * return int
6131  * @todo Finish documenting this function
6132  */
6133 function make_grades_menu($gradingtype) {
6134     $grades = array();
6135     if ($gradingtype < 0) {
6136         if ($scale = get_record('scale', 'id', - $gradingtype)) {
6137             return make_menu_from_list($scale->scale);
6138         }
6139     } else if ($gradingtype > 0) {
6140         for ($i=$gradingtype; $i>=0; $i--) {
6141             $grades[$i] = $i .' / '. $gradingtype;
6142         }
6143         return $grades;
6144     }
6145     return $grades;
6146 }
6147
6148 /**
6149  * This function returns the nummber of activities
6150  * using scaleid in a courseid
6151  *
6152  * @param int $courseid ?
6153  * @param int $scaleid ?
6154  * @return int
6155  * @todo Finish documenting this function
6156  */
6157 function course_scale_used($courseid, $scaleid) {
6158
6159     global $CFG;
6160
6161     $return = 0;
6162
6163     if (!empty($scaleid)) {
6164         if ($cms = get_course_mods($courseid)) {
6165             foreach ($cms as $cm) {
6166                 //Check cm->name/lib.php exists
6167                 if (file_exists($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php')) {
6168                     include_once($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php');
6169                     $function_name = $cm->modname.'_scale_used';
6170                     if (function_exists($function_name)) {
6171                         if ($function_name($cm->instance,$scaleid)) {
6172                             $return++;
6173                         }
6174                     }
6175                 }
6176             }
6177         }
6178
6179         // check if any course grade item makes use of the scale
6180         $return += count_records('grade_items', 'courseid', $courseid, 'scaleid', $scaleid);
6181     }
6182     return $return;
6183 }
6184
6185 /**
6186  * This function returns the nummber of activities
6187  * using scaleid in the entire site
6188  *
6189  * @param int $scaleid ?
6190  * @return int
6191  * @todo Finish documenting this function. Is return type correct?
6192  */
6193 function site_scale_used($scaleid,&$courses) {
6194
6195     global $CFG;
6196
6197     $return = 0;
6198
6199     if (!is_array($courses) || count($courses) == 0) {
6200         $courses = get_courses("all",false,"c.id,c.shortname");
6201     }
6202
6203     if (!empty($scaleid)) {
6204         if (is_array($courses) && count($courses) > 0) {
6205             foreach ($courses as $course) {
6206                 $return += course_scale_used($course->id,$scaleid);
6207             }
6208         }
6209     }
6210     return $return;
6211 }
6212
6213 /**
6214  * make_unique_id_code
6215  *
6216  * @param string $extra ?
6217  * @return string
6218  * @todo Finish documenting this function
6219  */
6220 function make_unique_id_code($extra='') {
6221
6222     $hostname = 'unknownhost';
6223     if (!empty($_SERVER['HTTP_HOST'])) {
6224         $hostname = $_SERVER['HTTP_HOST'];
6225     } else if (!empty($_ENV['HTTP_HOST'])) {
6226         $hostname = $_ENV['HTTP_HOST'];
6227     } else if (!empty($_SERVER['SERVER_NAME'])) {
6228         $hostname = $_SERVER['SERVER_NAME'];
6229     } else if (!empty($_ENV['SERVER_NAME'])) {
6230         $hostname = $_ENV['SERVER_NAME'];
6231     }
6232
6233     $date = gmdate("ymdHis");
6234
6235     $random =  random_string(6);
6236
6237     if ($extra) {
6238         return $hostname .'+'. $date .'+'. $random .'+'. $extra;
6239     } else {
6240         return $hostname .'+'. $date .'+'. $random;
6241     }
6242 }
6243
6244
6245 /**
6246  * Function to check the passed address is within the passed subnet
6247  *
6248  * The parameter is a comma separated string of subnet definitions.
6249  * Subnet strings can be in one of three formats:
6250  *   1: xxx.xxx.xxx.xxx/xx
6251  *   2: xxx.xxx
6252  *   3: xxx.xxx.xxx.xxx-xxx   //a range of IP addresses in the last group.
6253  * Code for type 1 modified from user posted comments by mediator at
6254  * {@link http://au.php.net/manual/en/function.ip2long.php}
6255  *
6256  * @param string $addr    The address you are checking
6257  * @param string $subnetstr    The string of subnet addresses
6258  * @return bool
6259  */
6260 function address_in_subnet($addr, $subnetstr) {
6261
6262     $subnets = explode(',', $subnetstr);
6263     $found = false;
6264     $addr = trim($addr);
6265
6266     foreach ($subnets as $subnet) {
6267         $subnet = trim($subnet);
6268         if (strpos($subnet, '/') !== false) { /// type 1
6269             list($ip, $mask) = explode('/', $subnet);
6270             $mask = 0xffffffff << (32 - $mask);
6271             $found = ((ip2long($addr) & $mask) == (ip2long($ip) & $mask));
6272         } else if (strpos($subnet, '-') !== false)  {/// type 3
6273             $subnetparts = explode('.', $subnet);
6274             $addrparts = explode('.', $addr);
6275             $subnetrange = explode('-', array_pop($subnetparts));
6276             if (count($subnetrange) == 2) {
6277                 $lastaddrpart = array_pop($addrparts);
6278                 $found = ($subnetparts == $addrparts &&
6279                         $subnetrange[0] <= $lastaddrpart && $lastaddrpart <= $subnetrange[1]);
6280             }
6281         } else { /// type 2
6282             $found = (strpos($addr, $subnet) === 0);
6283         }
6284
6285         if ($found) {
6286             break;
6287         }
6288     }
6289     return $found;
6290 }
6291
6292 /**
6293  * This function sets the $HTTPSPAGEREQUIRED global
6294  * (used in some parts of moodle to change some links)
6295  * and calculate the proper wwwroot to be used
6296  *
6297  * By using this function properly, we can ensure 100% https-ized pages
6298  * at our entire discretion (login, forgot_password, change_password)
6299  */
6300 function httpsrequired() {
6301
6302     global $CFG, $HTTPSPAGEREQUIRED;
6303
6304     if (!empty($CFG->loginhttps)) {
6305         $HTTPSPAGEREQUIRED = true;
6306         $CFG->httpswwwroot = str_replace('http:', 'https:', $CFG->wwwroot);
6307         $CFG->httpsthemewww = str_replace('http:', 'https:', $CFG->themewww);
6308
6309         // change theme URLs to https
6310         theme_setup();
6311
6312     } else {
6313         $CFG->httpswwwroot = $CFG->wwwroot;
6314         $CFG->httpsthemewww = $CFG->themewww;
6315     }
6316 }
6317
6318 /**
6319  * For outputting debugging info
6320  *
6321  * @uses STDOUT
6322  * @param string $string ?
6323  * @param string $eol ?
6324  * @todo Finish documenting this function
6325  */
6326 function mtrace($string, $eol="\n", $sleep=0) {
6327
6328     if (defined('STDOUT')) {
6329         fwrite(STDOUT, $string.$eol);
6330     } else {
6331         echo $string . $eol;
6332     }
6333
6334     flush();
6335
6336     //delay to keep message on user's screen in case of subsequent redirect
6337     if ($sleep) {
6338         sleep($sleep);
6339     }
6340 }
6341
6342 //Replace 1 or more slashes or backslashes to 1 slash
6343 function cleardoubleslashes ($path) {
6344     return preg_replace('/(\/|\\\){1,}/','/',$path);
6345 }
6346
6347 function zip_files ($originalfiles, $destination) {
6348 //Zip an array of files/dirs to a destination zip file
6349 //Both parameters must be FULL paths to the files/dirs
6350
6351     global $CFG;
6352
6353     //Extract everything from destination
6354     $path_parts = pathinfo(cleardoubleslashes($destination));
6355     $destpath = $path_parts["dirname"];       //The path of the zip file
6356     $destfilename = $path_parts["basename"];  //The name of the zip file
6357     $extension = $path_parts["extension"];    //The extension of the file
6358
6359     //If no file, error
6360     if (empty($destfilename)) {
6361         return false;
6362     }
6363
6364     //If no extension, add it
6365     if (empty($extension)) {
6366         $extension = 'zip';
6367         $destfilename = $destfilename.'.'.$extension;
6368     }
6369
6370     //Check destination path exists
6371     if (!is_dir($destpath)) {
6372         return false;
6373     }
6374
6375     //Check destination path is writable. TODO!!
6376
6377     //Clean destination filename
6378     $destfilename = clean_filename($destfilename);
6379
6380     //Now check and prepare every file
6381     $files = array();
6382     $origpath = NULL;
6383
6384     foreach ($originalfiles as $file) {  //Iterate over each file
6385         //Check for every file
6386         $tempfile = cleardoubleslashes($file); // no doubleslashes!
6387         //Calculate the base path for all files if it isn't set
6388         if ($origpath === NULL) {
6389             $origpath = rtrim(cleardoubleslashes(dirname($tempfile)), "/");
6390         }
6391         //See if the file is readable
6392         if (!is_readable($tempfile)) {  //Is readable
6393             continue;
6394         }
6395         //See if the file/dir is in the same directory than the rest
6396         if (rtrim(cleardoubleslashes(dirname($tempfile)), "/") != $origpath) {
6397             continue;
6398         }
6399         //Add the file to the array
6400         $files[] = $tempfile;
6401     }
6402
6403     //Everything is ready:
6404     //    -$origpath is the path where ALL the files to be compressed reside (dir).
6405     //    -$destpath is the destination path where the zip file will go (dir).
6406     //    -$files is an array of files/dirs to compress (fullpath)
6407     //    -$destfilename is the name of the zip file (without path)
6408
6409     //print_object($files);                  //Debug
6410
6411     if (empty($CFG->zip)) {    // Use built-in php-based zip function
6412
6413         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6414         //rewrite filenames because the old method with PCLZIP_OPT_REMOVE_PATH does not work under win32
6415         $zipfiles = array();
6416         $start = strlen($origpath)+1;
6417         foreach($files as $file) {
6418             $tf = array();
6419             $tf[PCLZIP_ATT_FILE_NAME] = $file;
6420             $tf[PCLZIP_ATT_FILE_NEW_FULL_NAME] = substr($file, $start);
6421             $zipfiles[] = $tf;
6422         }
6423         //create the archive
6424         $archive = new PclZip(cleardoubleslashes("$destpath/$destfilename"));
6425         if (($list = $archive->create($zipfiles) == 0)) {
6426             notice($archive->errorInfo(true));
6427             return false;
6428         }
6429
6430     } else {                   // Use external zip program
6431
6432         $filestozip = "";
6433         foreach ($files as $filetozip) {
6434             $filestozip .= escapeshellarg(basename($filetozip));
6435             $filestozip .= " ";
6436         }
6437         //Construct the command
6438         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6439         $command = 'cd '.escapeshellarg($origpath).$separator.
6440                     escapeshellarg($CFG->zip).' -r '.
6441                     escapeshellarg(cleardoubleslashes("$destpath/$destfilename")).' '.$filestozip;
6442         //All converted to backslashes in WIN
6443         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6444             $command = str_replace('/','\\',$command);
6445         }
6446         Exec($command);
6447     }
6448     return true;
6449 }
6450
6451 function unzip_file ($zipfile, $destination = '', $showstatus = true) {
6452 //Unzip one zip file to a destination dir
6453 //Both parameters must be FULL paths
6454 //If destination isn't specified, it will be the
6455 //SAME directory where the zip file resides.
6456
6457     global $CFG;
6458
6459     //Extract everything from zipfile
6460     $path_parts = pathinfo(cleardoubleslashes($zipfile));
6461     $zippath = $path_parts["dirname"];       //The path of the zip file
6462     $zipfilename = $path_parts["basename"];  //The name of the zip file
6463     $extension = $path_parts["extension"];    //The extension of the file
6464
6465     //If no file, error
6466     if (empty($zipfilename)) {
6467         return false;
6468     }
6469
6470     //If no extension, error
6471     if (empty($extension)) {
6472         return false;
6473     }
6474
6475     //Clear $zipfile
6476     $zipfile = cleardoubleslashes($zipfile);
6477
6478     //Check zipfile exists
6479     if (!file_exists($zipfile)) {
6480         return false;
6481     }
6482
6483     //If no destination, passed let's go with the same directory
6484     if (empty($destination)) {
6485         $destination = $zippath;
6486     }
6487
6488     //Clear $destination
6489     $destpath = rtrim(cleardoubleslashes($destination), "/");
6490
6491     //Check destination path exists
6492     if (!is_dir($destpath)) {
6493         return false;
6494     }
6495
6496     //Check destination path is writable. TODO!!
6497
6498     //Everything is ready:
6499     //    -$zippath is the path where the zip file resides (dir)
6500     //    -$zipfilename is the name of the zip file (without path)
6501     //    -$destpath is the destination path where the zip file will uncompressed (dir)
6502
6503     $list = null;
6504
6505     if (empty($CFG->unzip)) {    // Use built-in php-based unzip function
6506
6507         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6508         $archive = new PclZip(cleardoubleslashes("$zippath/$zipfilename"));
6509         if (!$list = $archive->extract(PCLZIP_OPT_PATH, $destpath,
6510                                        PCLZIP_CB_PRE_EXTRACT, 'unzip_cleanfilename',
6511                                        PCLZIP_OPT_EXTRACT_DIR_RESTRICTION, $destpath)) {
6512             notice($archive->errorInfo(true));
6513             return false;
6514         }
6515
6516     } else {                     // Use external unzip program
6517
6518         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6519         $redirection = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? '' : ' 2>&1';
6520
6521         $command = 'cd '.escapeshellarg($zippath).$separator.
6522                     escapeshellarg($CFG->unzip).' -o '.
6523                     escapeshellarg(cleardoubleslashes("$zippath/$zipfilename")).' -d '.
6524                     escapeshellarg($destpath).$redirection;
6525         //All converted to backslashes in WIN
6526         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6527             $command = str_replace('/','\\',$command);
6528         }
6529         Exec($command,$list);
6530     }
6531
6532     //Display some info about the unzip execution
6533     if ($showstatus) {
6534         unzip_show_status($list,$destpath);
6535     }
6536
6537     return true;
6538 }
6539
6540 function unzip_cleanfilename ($p_event, &$p_header) {
6541 //This function is used as callback in unzip_file() function
6542 //to clean illegal characters for given platform and to prevent directory traversal.
6543 //Produces the same result as info-zip unzip.
6544     $p_header['filename'] = ereg_replace('[[:cntrl:]]', '', $p_header['filename']); //strip control chars first!
6545     $p_header['filename'] = ereg_replace('\.\.+', '', $p_header['filename']); //directory traversal protection
6546     if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6547         $p_header['filename'] = ereg_replace('[:*"?<>|]', '_', $p_header['filename']); //replace illegal chars
6548         $p_header['filename'] = ereg_replace('^([a-zA-Z])_', '\1:', $p_header['filename']); //repair drive letter
6549     } else {
6550         //Add filtering for other systems here
6551         // BSD: none (tested)
6552         // Linux: ??
6553         // MacosX: ??
6554     }
6555     $p_header['filename'] = cleardoubleslashes($p_header['filename']); //normalize the slashes/backslashes
6556     return 1;
6557 }
6558
6559 function unzip_show_status ($list,$removepath) {
6560 //This function shows the results of the unzip execution
6561 //depending of the value of the $CFG->zip, results will be
6562 //text or an array of files.
6563
6564     global $CFG;
6565
6566     if (empty($CFG->unzip)) {    // Use built-in php-based zip function
6567         $strname = get_string("name");
6568         $strsize = get_string("size");
6569         $strmodified = get_string("modified");
6570         $strstatus = get_string("status");
6571         echo "<table width=\"640\">";
6572         echo "<tr><th class=\"header\" scope=\"col\">$strname</th>";
6573         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strsize</th>";
6574         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strmodified</th>";
6575         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strstatus</th></tr>";
6576         foreach ($list as $item) {
6577             echo "<tr>";
6578             $item['filename'] = str_replace(cleardoubleslashes($removepath).'/', "", $item['filename']);
6579             print_cell("left", s($item['filename']));
6580             if (! $item['folder']) {
6581                 print_cell("right", display_size($item['size']));
6582             } else {
6583                 echo "<td>&nbsp;</td>";
6584             }
6585             $filedate  = userdate($item['mtime'], get_string("strftimedatetime"));
6586             print_cell("right", $filedate);
6587             print_cell("right", $item['status']);
6588             echo "</tr>";
6589         }
6590         echo "</table>";
6591
6592     } else {                   // Use external zip program
6593         print_simple_box_start("center");
6594         echo "<pre>";
6595         foreach ($list as $item) {
6596             echo s(str_replace(cleardoubleslashes($removepath.'/'), '', $item)).'<br />';
6597         }
6598         echo "</pre>";
6599         print_simple_box_end();
6600     }
6601 }
6602
6603 /**
6604  * Returns most reliable client address
6605  *
6606  * @return string The remote IP address
6607  */
6608  function getremoteaddr() {
6609     if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
6610         return cleanremoteaddr($_SERVER['HTTP_CLIENT_IP']);
6611     }
6612     if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
6613         return cleanremoteaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
6614     }
6615     if (!empty($_SERVER['REMOTE_ADDR'])) {
6616         return cleanremoteaddr($_SERVER['REMOTE_ADDR']);
6617     }
6618     return '';
6619 }
6620
6621 /**
6622  * Cleans a remote address ready to put into the log table
6623  */
6624 function cleanremoteaddr($addr) {
6625     $originaladdr = $addr;
6626     $matches = array();
6627     // first get all things that look like IP addresses.
6628     if (!preg_match_all('/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/',$addr,$matches,PREG_SET_ORDER)) {
6629         return '';
6630     }
6631     $goodmatches = array();
6632     $lanmatches = array();
6633     foreach ($matches as $match) {
6634         //        print_r($match);
6635         // check to make sure it's not an internal address.
6636         // the following are reserved for private lans...
6637         // 10.0.0.0 - 10.255.255.255
6638         // 172.16.0.0 - 172.31.255.255
6639         // 192.168.0.0 - 192.168.255.255
6640         // 169.254.0.0 -169.254.255.255
6641         $bits = explode('.',$match[0]);
6642         if (count($bits) != 4) {
6643             // weird, preg match shouldn't give us it.
6644             continue;
6645         }
6646         if (($bits[0] == 10)
6647             || ($bits[0] == 172 && $bits[1] >= 16 && $bits[1] <= 31)
6648             || ($bits[0] == 192 && $bits[1] == 168)
6649             || ($bits[0] == 169 && $bits[1] == 254)) {
6650             $lanmatches[] = $match[0];
6651             continue;
6652         }
6653         // finally, it's ok
6654         $goodmatches[] = $match[0];
6655     }
6656     if (!count($goodmatches)) {
6657         // perhaps we have a lan match, it's probably better to return that.
6658         if (!count($lanmatches)) {
6659             return '';
6660         } else {
6661             return array_pop($lanmatches);
6662         }
6663     }
6664     if (count($goodmatches) == 1) {
6665         return $goodmatches[0];
6666     }
6667     error_log("NOTICE: cleanremoteaddr gives us something funny: $originaladdr had ".count($goodmatches)." matches");
6668     // we need to return something, so
6669     return array_pop($goodmatches);
6670 }
6671
6672 /**
6673  * file_put_contents is only supported by php 5.0 and higher
6674  * so if it is not predefined, define it here
6675  *
6676  * @param $file full path of the file to write
6677  * @param $contents contents to be sent
6678  * @return number of bytes written (false on error)
6679  */
6680 if(!function_exists('file_put_contents')) {
6681     function file_put_contents($file, $contents) {
6682         $result = false;
6683         if ($f = fopen($file, 'w')) {
6684             $result = fwrite($f, $contents);
6685             fclose($f);
6686         }
6687         return $result;
6688     }
6689 }
6690
6691 /**
6692  * The clone keyword is only supported from PHP 5 onwards.
6693  * The behaviour of $obj2 = $obj1 differs fundamentally
6694  * between PHP 4 and PHP 5. In PHP 4 a copy of $obj1 was
6695  * created, in PHP 5 $obj1 is referenced. To create a copy
6696  * in PHP 5 the clone keyword was introduced. This function
6697  * simulates this behaviour for PHP < 5.0.0.
6698  * See also: http://mjtsai.com/blog/2004/07/15/php-5-object-references/
6699  *
6700  * Modified 2005-09-29 by Eloy (from Julian Sedding proposal)
6701  * Found a better implementation (more checks and possibilities) from PEAR:
6702  * http://cvs.php.net/co.php/pear/PHP_Compat/Compat/Function/clone.php
6703  *
6704  * @param object $obj
6705  * @return object
6706  */
6707 if(!check_php_version('5.0.0')) {
6708 // the eval is needed to prevent PHP 5 from getting a parse error!
6709 eval('
6710     function clone($obj) {
6711     /// Sanity check
6712         if (!is_object($obj)) {
6713             user_error(\'clone() __clone method called on non-object\', E_USER_WARNING);
6714             return;
6715         }
6716
6717     /// Use serialize/unserialize trick to deep copy the object
6718         $obj = unserialize(serialize($obj));
6719
6720     /// If there is a __clone method call it on the "new" class
6721         if (method_exists($obj, \'__clone\')) {
6722             $obj->__clone();
6723         }
6724
6725         return $obj;
6726     }
6727
6728     // Supply the PHP5 function scandir() to older versions.
6729     function scandir($directory) {
6730         $files = array();
6731         if ($dh = opendir($directory)) {
6732             while (($file = readdir($dh)) !== false) {
6733                $files[] = $file;
6734             }
6735             closedir($dh);
6736         }
6737         return $files;
6738     }
6739
6740     // Supply the PHP5 function array_combine() to older versions.
6741     function array_combine($keys, $values) {
6742         if (!is_array($keys) || !is_array($values) || count($keys) != count($values)) {
6743             return false;
6744         }
6745         reset($values);
6746         $result = array();
6747         foreach ($keys as $key) {
6748             $result[$key] = current($values);
6749             next($values);
6750         }
6751         return $result;
6752     }
6753 ');
6754 }
6755
6756 /**
6757  * This function will make a complete copy of anything it's given,
6758  * regardless of whether it's an object or not.
6759  * @param mixed $thing
6760  * @return mixed
6761  */
6762 function fullclone($thing) {
6763     return unserialize(serialize($thing));
6764 }
6765
6766
6767 /*
6768  * This function expects to called during shutdown
6769  * should be set via register_shutdown_function()
6770  * in lib/setup.php .
6771  *
6772  * Right now we do it only if we are under apache, to
6773  * make sure apache children that hog too much mem are
6774  * killed.
6775  *
6776  */
6777 function moodle_request_shutdown() {
6778
6779     global $CFG;
6780
6781     // initially, we are only ever called under apache
6782     // but check just in case
6783     if (function_exists('apache_child_terminate')
6784         && function_exists('memory_get_usage')
6785         && ini_get_bool('child_terminate')) {
6786         if (empty($CFG->apachemaxmem)) {
6787             $CFG->apachemaxmem = 25000000; // default 25MiB
6788         }
6789         if (memory_get_usage() > (int)$CFG->apachemaxmem) {
6790             trigger_error('Mem usage over $CFG->apachemaxmem: marking child for reaping.');
6791             @apache_child_terminate();
6792         }
6793     }
6794 }
6795
6796 /**
6797  * If new messages are waiting for the current user, then return
6798  * Javascript code to create a popup window
6799  *
6800  * @return string Javascript code
6801  */
6802 function message_popup_window() {
6803     global $USER;
6804
6805     $popuplimit = 30;     // Minimum seconds between popups
6806
6807     if (!defined('MESSAGE_WINDOW')) {
6808         if (isset($USER->id)) {
6809             if (!isset($USER->message_lastpopup)) {
6810                 $USER->message_lastpopup = 0;
6811             }
6812             if ((time() - $USER->message_lastpopup) > $popuplimit) {  /// It's been long enough
6813                 if (get_user_preferences('message_showmessagewindow', 1) == 1) {
6814                     if (count_records_select('message', 'useridto = \''.$USER->id.'\' AND timecreated > \''.$USER->message_lastpopup.'\'')) {
6815                         $USER->message_lastpopup = time();
6816                         return '<script type="text/javascript">'."\n//<![CDATA[\n openpopup('/message/index.php', 'message',
6817                         'menubar=0,location=0,scrollbars,status,resizable,width=400,height=500', 0);\n//]]>\n</script>";
6818                     }
6819                 }
6820             }
6821         }
6822     }
6823
6824     return '';
6825 }
6826
6827 // Used to make sure that $min <= $value <= $max
6828 function bounded_number($min, $value, $max) {
6829     if($value < $min) {
6830         return $min;
6831     }
6832     if($value > $max) {
6833         return $max;
6834     }
6835     return $value;
6836 }
6837
6838 function array_is_nested($array) {
6839     foreach ($array as $value) {
6840         if (is_array($value)) {
6841             return true;
6842         }
6843     }
6844     return false;
6845 }
6846
6847 /**
6848  *** get_performance_info() pairs up with init_performance_info()
6849  *** loaded in setup.php. Returns an array with 'html' and 'txt'
6850  *** values ready for use, and each of the individual stats provided
6851  *** separately as well.
6852  ***
6853  **/
6854 function get_performance_info() {
6855     global $CFG, $PERF, $rcache;
6856
6857     $info = array();
6858     $info['html'] = '';         // holds userfriendly HTML representation
6859     $info['txt']  = me() . ' '; // holds log-friendly representation
6860
6861     $info['realtime'] = microtime_diff($PERF->starttime, microtime());
6862
6863     $info['html'] .= '<span class="timeused">'.$info['realtime'].' secs</span> ';
6864     $info['txt'] .= 'time: '.$info['realtime'].'s ';
6865
6866     if (function_exists('memory_get_usage')) {
6867         $info['memory_total'] = memory_get_usage();
6868         $info['memory_growth'] = memory_get_usage() - $PERF->startmemory;
6869         $info['html'] .= '<span class="memoryused">RAM: '.display_size($info['memory_total']).'</span> ';
6870         $info['txt']  .= 'memory_total: '.$info['memory_total'].'B (' . display_size($info['memory_total']).') memory_growth: '.$info['memory_growth'].'B ('.display_size($info['memory_growth']).') ';
6871     }
6872
6873     $inc = get_included_files();
6874     //error_log(print_r($inc,1));
6875     $info['includecount'] = count($inc);
6876     $info['html'] .= '<span class="included">Included '.$info['includecount'].' files</span> ';
6877     $info['txt']  .= 'includecount: '.$info['includecount'].' ';
6878
6879     if (!empty($PERF->dbqueries)) {
6880         $info['dbqueries'] = $PERF->dbqueries;
6881         $info['html'] .= '<span class="dbqueries">DB queries '.$info['dbqueries'].'</span> ';
6882         $info['txt'] .= 'dbqueries: '.$info['dbqueries'].' ';
6883     }
6884
6885     if (!empty($PERF->logwrites)) {
6886         $info['logwrites'] = $PERF->logwrites;
6887         $info['html'] .= '<span class="logwrites">Log writes '.$info['logwrites'].'</span> ';
6888         $info['txt'] .= 'logwrites: '.$info['logwrites'].' ';
6889     }
6890
6891     if (!empty($PERF->profiling) && $PERF->profiling) {
6892         require_once($CFG->dirroot .'/lib/profilerlib.php');
6893         $info['html'] .= '<span class="profilinginfo">'.Profiler::get_profiling(array('-R')).'</span>';
6894     }
6895
6896     if (function_exists('posix_times')) {
6897         $ptimes = posix_times();
6898         if (is_array($ptimes)) {
6899             foreach ($ptimes as $key => $val) {
6900                 $info[$key] = $ptimes[$key] -  $PERF->startposixtimes[$key];
6901             }
6902             $info['html'] .= "<span class=\"posixtimes\">ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime]</span> ";
6903             $info['txt'] .= "ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime] ";
6904         }
6905     }
6906
6907     // Grab the load average for the last minute
6908     // /proc will only work under some linux configurations
6909     // while uptime is there under MacOSX/Darwin and other unices
6910     if (is_readable('/proc/loadavg') && $loadavg = @file('/proc/loadavg')) {
6911         list($server_load) = explode(' ', $loadavg[0]);
6912         unset($loadavg);
6913     } else if ( function_exists('is_executable') && is_executable('/usr/bin/uptime') && $loadavg = `/usr/bin/uptime` ) {
6914         if (preg_match('/load averages?: (\d+[\.,:]\d+)/', $loadavg, $matches)) {
6915             $server_load = $matches[1];
6916         } else {
6917             trigger_error('Could not parse uptime output!');
6918         }
6919     }
6920     if (!empty($server_load)) {
6921         $info['serverload'] = $server_load;
6922         $info['html'] .= '<span class="serverload">Load average: '.$info['serverload'].'</span> ';
6923         $info['txt'] .= "serverload: {$info['serverload']} ";
6924     }
6925
6926     if (isset($rcache->hits) && isset($rcache->misses)) {
6927         $info['rcachehits'] = $rcache->hits;
6928         $info['rcachemisses'] = $rcache->misses;
6929         $info['html'] .= '<span class="rcache">Record cache hit/miss ratio : '.
6930             "{$rcache->hits}/{$rcache->misses}</span> ";
6931         $info['txt'] .= 'rcache: '.
6932             "{$rcache->hits}/{$rcache->misses} ";
6933     }
6934     $info['html'] = '<div class="performanceinfo">'.$info['html'].'</div>';
6935     return $info;
6936 }
6937
6938 function apd_get_profiling() {
6939     return shell_exec('pprofp -u ' . ini_get('apd.dumpdir') . '/pprof.' . getmypid() . '.*');
6940 }
6941
6942 function remove_dir($dir, $content_only=false) {
6943     // if content_only=true then delete all but
6944     // the directory itself
6945
6946     $handle = opendir($dir);
6947     while (false!==($item = readdir($handle))) {
6948         if($item != '.' && $item != '..') {
6949             if(is_dir($dir.'/'.$item)) {
6950                 remove_dir($dir.'/'.$item);
6951             }else{
6952                 unlink($dir.'/'.$item);
6953             }
6954         }
6955     }
6956     closedir($handle);
6957     if ($content_only) {
6958         return true;
6959     }
6960     return rmdir($dir);
6961 }
6962
6963 /**
6964  * Function to check if a directory exists and optionally create it.
6965  *
6966  * @param string absolute directory path
6967  * @param boolean create directory if does not exist
6968  * @param boolean create directory recursively
6969  *
6970  * @return boolean true if directory exists or created
6971  */
6972 function check_dir_exists($dir, $create=false, $recursive=false) {
6973
6974     global $CFG;
6975
6976     $status = true;
6977
6978     if(!is_dir($dir)) {
6979         if (!$create) {
6980             $status = false;
6981         } else {
6982             umask(0000);
6983             if ($recursive) {
6984                 // PHP 5.0 has recursive mkdir parameter, but 4.x does not :-(
6985                 $dir = str_replace('\\', '/', $dir); //windows compatibility
6986                 $dirs = explode('/', $dir);
6987                 $dir = array_shift($dirs).'/'; //skip root or drive letter
6988                 foreach ($dirs as $part) {
6989                     if ($part == '') {
6990                         continue;
6991                     }
6992                     $dir .= $part.'/';
6993                     if (!is_dir($dir)) {
6994                         if (!mkdir($dir, $CFG->directorypermissions)) {
6995                             $status = false;
6996                             break;
6997                         }
6998                     }
6999                 }
7000             } else {
7001                 $status = mkdir($dir, $CFG->directorypermissions);
7002             }
7003         }
7004     }
7005     return $status;
7006 }
7007
7008 function report_session_error() {
7009     global $CFG, $FULLME;
7010
7011     if (empty($CFG->lang)) {
7012         $CFG->lang = "en";
7013     }
7014     // Set up default theme and locale
7015     theme_setup();
7016     moodle_setlocale();
7017
7018     //clear session cookies
7019     setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7020     setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7021     //increment database error counters
7022     if (isset($CFG->session_error_counter)) {
7023         set_config('session_error_counter', 1 + $CFG->session_error_counter);
7024     } else {
7025         set_config('session_error_counter', 1);
7026     }
7027     redirect($FULLME, get_string('sessionerroruser2', 'error'), 5);
7028 }
7029
7030
7031 /**
7032  * Detect if an object or a class contains a given property
7033  * will take an actual object or the name of a class
7034  * @param mix $obj Name of class or real object to test
7035  * @param string $property name of property to find
7036  * @return bool true if property exists
7037  */
7038 function object_property_exists( $obj, $property ) {
7039     if (is_string( $obj )) {
7040         $properties = get_class_vars( $obj );
7041     }
7042     else {
7043         $properties = get_object_vars( $obj );
7044     }
7045     return array_key_exists( $property, $properties );
7046 }
7047
7048
7049 /**
7050  * Detect a custom script replacement in the data directory that will
7051  * replace an existing moodle script
7052  * @param string $urlpath path to the original script
7053  * @return string full path name if a custom script exists
7054  * @return bool false if no custom script exists
7055  */
7056 function custom_script_path($urlpath='') {
7057     global $CFG;
7058
7059     // set default $urlpath, if necessary
7060     if (empty($urlpath)) {
7061         $urlpath = qualified_me(); // e.g. http://www.this-server.com/moodle/this-script.php
7062     }
7063
7064     // $urlpath is invalid if it is empty or does not start with the Moodle wwwroot
7065     if (empty($urlpath) or (strpos($urlpath, $CFG->wwwroot) === false )) {
7066         return false;
7067     }
7068
7069     // replace wwwroot with the path to the customscripts folder and clean path
7070     $scriptpath = $CFG->customscripts . clean_param(substr($urlpath, strlen($CFG->wwwroot)), PARAM_PATH);
7071
7072     // remove the query string, if any
7073     if (($strpos = strpos($scriptpath, '?')) !== false) {
7074         $scriptpath = substr($scriptpath, 0, $strpos);
7075     }
7076
7077     // remove trailing slashes, if any
7078     $scriptpath = rtrim($scriptpath, '/\\');
7079
7080     // append index.php, if necessary
7081     if (is_dir($scriptpath)) {
7082         $scriptpath .= '/index.php';
7083     }
7084
7085     // check the custom script exists
7086     if (file_exists($scriptpath)) {
7087         return $scriptpath;
7088     } else {
7089         return false;
7090     }
7091 }
7092
7093 /**
7094  * Wrapper function to load necessary editor scripts
7095  * to $CFG->editorsrc array. Params can be coursei id
7096  * or associative array('courseid' => value, 'name' => 'editorname').
7097  * @uses $CFG
7098  * @param mixed $args Courseid or associative array.
7099  */
7100 function loadeditor($args) {
7101     global $CFG;
7102     include($CFG->libdir .'/editorlib.php');
7103     return editorObject::loadeditor($args);
7104 }
7105
7106 /**
7107  * Returns whether or not the user object is a remote MNET user. This function
7108  * is in moodlelib because it does not rely on loading any of the MNET code.
7109  *
7110  * @param object $user A valid user object
7111  * @return bool        True if the user is from a remote Moodle.
7112  */
7113 function is_mnet_remote_user($user) {
7114     global $CFG;
7115
7116     if (!isset($CFG->mnet_localhost_id)) {
7117         include_once $CFG->dirroot . '/mnet/lib.php';
7118         $env = new mnet_environment();
7119         $env->init();
7120         unset($env);
7121     }
7122
7123     return (!empty($user->mnethostid) && $user->mnethostid != $CFG->mnet_localhost_id);
7124 }
7125
7126 /**
7127  * Checks if a given plugin is in the list of enabled enrolment plugins.
7128  *
7129  * @param string $auth Enrolment plugin.
7130  * @return boolean Whether the plugin is enabled.
7131  */
7132 function is_enabled_enrol($enrol='') {
7133     global $CFG;
7134
7135     // use the global default if not specified
7136     if ($enrol == '') {
7137         $enrol = $CFG->enrol;
7138     }
7139     return in_array($enrol, explode(',', $CFG->enrol_plugins_enabled));
7140 }
7141
7142 /**
7143  * This function will search for browser prefereed languages, setting Moodle
7144  * to use the best one available if $SESSION->lang is undefined
7145  */
7146 function setup_lang_from_browser() {
7147
7148     global $CFG, $SESSION, $USER;
7149
7150     if (!empty($SESSION->lang) or !empty($USER->lang)) {
7151         // Lang is defined in session or user profile, nothing to do
7152         return;
7153     }
7154
7155     if (!isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) { // There isn't list of browser langs, nothing to do
7156         return;
7157     }
7158
7159 /// Extract and clean langs from headers
7160     $rawlangs = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
7161     $rawlangs = str_replace('-', '_', $rawlangs);         // we are using underscores
7162     $rawlangs = explode(',', $rawlangs);                  // Convert to array
7163     $langs = array();
7164
7165     $order = 1.0;
7166     foreach ($rawlangs as $lang) {
7167         if (strpos($lang, ';') === false) {
7168             $langs[(string)$order] = $lang;
7169             $order = $order-0.01;
7170         } else {
7171             $parts = explode(';', $lang);
7172             $pos = strpos($parts[1], '=');
7173             $langs[substr($parts[1], $pos+1)] = $parts[0];
7174         }
7175     }
7176     krsort($langs, SORT_NUMERIC);
7177
7178     $langlist = get_list_of_languages();
7179
7180 /// Look for such langs under standard locations
7181     foreach ($langs as $lang) {
7182         $lang = strtolower(clean_param($lang.'_utf8', PARAM_SAFEDIR)); // clean it properly for include
7183         if (!array_key_exists($lang, $langlist)) {
7184             continue; // language not allowed, try next one
7185         }
7186         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
7187             $SESSION->lang = $lang; /// Lang exists, set it in session
7188             break; /// We have finished. Go out
7189         }
7190     }
7191     return;
7192 }
7193
7194
7195 ////////////////////////////////////////////////////////////////////////////////
7196
7197 function is_newnav($navigation) {
7198     if (is_array($navigation) && !empty($navigation['newnav'])) {
7199         return true;
7200     } else {
7201         return false;
7202     }
7203 }
7204
7205 /**
7206  * Checks whether the given variable name is defined as a variable within the given object.
7207  * @note This will NOT work with stdClass objects, which have no class variables.
7208  * @param string $var The variable name
7209  * @param object $object The object to check
7210  * @return boolean
7211  */
7212 function in_object_vars($var, $object) {
7213     $class_vars = get_class_vars(get_class($object));
7214     $class_vars = array_keys($class_vars);
7215     return in_array($var, $class_vars);
7216 }
7217
7218 /**
7219  * Returns an array without repeated objects.
7220  * This function is similar to array_unique, but for arrays that have objects as values
7221  *
7222  * @param unknown_type $array
7223  * @param unknown_type $keep_key_assoc
7224  * @return unknown
7225  */
7226 function object_array_unique($array, $keep_key_assoc = true) {
7227     $duplicate_keys = array();
7228     $tmp         = array();
7229
7230     foreach ($array as $key=>$val) {
7231         // convert objects to arrays, in_array() does not support objects
7232         if (is_object($val)) {
7233             $val = (array)$val;
7234         }
7235
7236         if (!in_array($val, $tmp)) {
7237             $tmp[] = $val;
7238         } else {
7239             $duplicate_keys[] = $key;
7240         }
7241     }
7242
7243     foreach ($duplicate_keys as $key) {
7244         unset($array[$key]);
7245     }
7246
7247     return $keep_key_assoc ? $array : array_values($array);
7248 }
7249
7250 // vim:autoindent:expandtab:shiftwidth=4:tabstop=4:tw=140:
7251 ?>