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 onwards 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_TAG - one tag (interests, blogs, etc.) - mostly international alphanumeric with spaces
 153  */
 154 define('PARAM_TAG',   0x0011);
 155
 156 /**
 157  * PARAM_TAGLIST - list of tags separated by commas (interests, blogs, etc.)
 158  */
 159 define('PARAM_TAGLIST',   0x0012);
 160
 161 /**
 162  * PARAM_PATH - safe relative path name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 163  * note: the leading slash is not removed, window drive letter is not allowed
 164  */
 165 define('PARAM_PATH',     0x0020);
 166
 167 /**
 168  * PARAM_HOST - expected fully qualified domain name (FQDN) or an IPv4 dotted quad (IP address)
 169  */
 170 define('PARAM_HOST',     0x0040);
 171
 172 /**
 173  * PARAM_URL - expected properly formatted URL. Please note that domain part is required, http://localhost/ is not acceppted but http://localhost.localdomain/ is ok.
 174  */
 175 define('PARAM_URL',      0x0080);
 176
 177 /**
 178  * 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!)
 179  */
 180 define('PARAM_LOCALURL', 0x0180);
 181
 182 /**
 183  * PARAM_CLEANFILE - safe file name, all dangerous and regional chars are removed,
 184  * use when you want to store a new file submitted by students
 185  */
 186 define('PARAM_CLEANFILE',0x0200);
 187
 188 /**
 189  * PARAM_ALPHANUM - expected numbers and letters only.
 190  */
 191 define('PARAM_ALPHANUM', 0x0400);
 192
 193 /**
 194  * PARAM_BOOL - converts input into 0 or 1, use for switches in forms and urls.
 195  */
 196 define('PARAM_BOOL',     0x0800);
 197
 198 /**
 199  * PARAM_CLEANHTML - cleans submitted HTML code and removes slashes
 200  * note: do not forget to addslashes() before storing into database!
 201  */
 202 define('PARAM_CLEANHTML',0x1000);
 203
 204 /**
 205  * PARAM_ALPHAEXT the same contents as PARAM_ALPHA plus the chars in quotes: "/-_" allowed,
 206  * suitable for include() and require()
 207  * @TODO: should we rename this function to PARAM_SAFEDIRS??
 208  */
 209 define('PARAM_ALPHAEXT', 0x2000);
 210
 211 /**
 212  * PARAM_SAFEDIR - safe directory name, suitable for include() and require()
 213  */
 214 define('PARAM_SAFEDIR',  0x4000);
 215
 216 /**
 217  * PARAM_SEQUENCE - expects a sequence of numbers like 8 to 1,5,6,4,6,8,9.  Numbers and comma only.
 218  */
 219 define('PARAM_SEQUENCE',  0x8000);
 220
 221 /**
 222  * PARAM_PEM - Privacy Enhanced Mail format
 223  */
 224 define('PARAM_PEM',      0x10000);
 225
 226 /**
 227  * PARAM_BASE64 - Base 64 encoded format
 228  */
 229 define('PARAM_BASE64',   0x20000);
 230
 231
 232 /// Page types ///
 233 /**
 234  * PAGE_COURSE_VIEW is a definition of a page type. For more information on the page class see moodle/lib/pagelib.php.
 235  */
 236 define('PAGE_COURSE_VIEW', 'course-view');
 237
 238 /// Debug levels ///
 239 /** no warnings at all */
 240 define ('DEBUG_NONE', 0);
 241 /** E_ERROR | E_PARSE */
 242 define ('DEBUG_MINIMAL', 5);
 243 /** E_ERROR | E_PARSE | E_WARNING | E_NOTICE */
 244 define ('DEBUG_NORMAL', 15);
 245 /** E_ALL without E_STRICT and E_RECOVERABLE_ERROR for now */
 246 define ('DEBUG_ALL', 2047);
 247 /** DEBUG_ALL with extra Moodle debug messages - (DEBUG_ALL | 32768) */
 248 define ('DEBUG_DEVELOPER', 34815);
 249
 250 /**
 251  * Blog access level constant declaration
 252  */
 253 define ('BLOG_USER_LEVEL', 1);
 254 define ('BLOG_GROUP_LEVEL', 2);
 255 define ('BLOG_COURSE_LEVEL', 3);
 256 define ('BLOG_SITE_LEVEL', 4);
 257 define ('BLOG_GLOBAL_LEVEL', 5);
 258
 259 /**
 260  * Tag constanst
 261  */
 262 define('TAG_MAX_LENGTH', 50);
 263
 264
 265
 266 /// PARAMETER HANDLING ////////////////////////////////////////////////////
 267
 268 /**
 269  * Returns a particular value for the named variable, taken from
 270  * POST or GET.  If the parameter doesn't exist then an error is
 271  * thrown because we require this variable.
 272  *
 273  * This function should be used to initialise all required values
 274  * in a script that are based on parameters.  Usually it will be
 275  * used like this:
 276  *    $id = required_param('id');
 277  *
 278  * @param string $parname the name of the page parameter we want
 279  * @param int $type expected type of parameter
 280  * @return mixed
 281  */
 282 function required_param($parname, $type=PARAM_CLEAN) {
 283
 284     // detect_unchecked_vars addition
 285     global $CFG;
 286     if (!empty($CFG->detect_unchecked_vars)) {
 287         global $UNCHECKED_VARS;
 288         unset ($UNCHECKED_VARS->vars[$parname]);
 289     }
 290
 291     if (isset($_POST[$parname])) {       // POST has precedence
 292         $param = $_POST[$parname];
 293     } else if (isset($_GET[$parname])) {
 294         $param = $_GET[$parname];
 295     } else {
 296         error('A required parameter ('.$parname.') was missing');
 297     }
 298
 299     return clean_param($param, $type);
 300 }
 301
 302 /**
 303  * Returns a particular value for the named variable, taken from
 304  * POST or GET, otherwise returning a given default.
 305  *
 306  * This function should be used to initialise all optional values
 307  * in a script that are based on parameters.  Usually it will be
 308  * used like this:
 309  *    $name = optional_param('name', 'Fred');
 310  *
 311  * @param string $parname the name of the page parameter we want
 312  * @param mixed  $default the default value to return if nothing is found
 313  * @param int $type expected type of parameter
 314  * @return mixed
 315  */
 316 function optional_param($parname, $default=NULL, $type=PARAM_CLEAN) {
 317
 318     // detect_unchecked_vars addition
 319     global $CFG;
 320     if (!empty($CFG->detect_unchecked_vars)) {
 321         global $UNCHECKED_VARS;
 322         unset ($UNCHECKED_VARS->vars[$parname]);
 323     }
 324
 325     if (isset($_POST[$parname])) {       // POST has precedence
 326         $param = $_POST[$parname];
 327     } else if (isset($_GET[$parname])) {
 328         $param = $_GET[$parname];
 329     } else {
 330         return $default;
 331     }
 332
 333     return clean_param($param, $type);
 334 }
 335
 336 /**
 337  * Used by {@link optional_param()} and {@link required_param()} to
 338  * clean the variables and/or cast to specific types, based on
 339  * an options field.
 340  * <code>
 341  * $course->format = clean_param($course->format, PARAM_ALPHA);
 342  * $selectedgrade_item = clean_param($selectedgrade_item, PARAM_CLEAN);
 343  * </code>
 344  *
 345  * @uses $CFG
 346  * @uses PARAM_CLEAN
 347  * @uses PARAM_INT
 348  * @uses PARAM_INTEGER
 349  * @uses PARAM_ALPHA
 350  * @uses PARAM_ALPHANUM
 351  * @uses PARAM_NOTAGS
 352  * @uses PARAM_ALPHAEXT
 353  * @uses PARAM_BOOL
 354  * @uses PARAM_SAFEDIR
 355  * @uses PARAM_CLEANFILE
 356  * @uses PARAM_FILE
 357  * @uses PARAM_PATH
 358  * @uses PARAM_HOST
 359  * @uses PARAM_URL
 360  * @uses PARAM_LOCALURL
 361  * @uses PARAM_CLEANHTML
 362  * @uses PARAM_SEQUENCE
 363  * @param mixed $param the variable we are cleaning
 364  * @param int $type expected format of param after cleaning.
 365  * @return mixed
 366  */
 367 function clean_param($param, $type) {
 368
 369     global $CFG;
 370
 371     if (is_array($param)) {              // Let's loop
 372         $newparam = array();
 373         foreach ($param as $key => $value) {
 374             $newparam[$key] = clean_param($value, $type);
 375         }
 376         return $newparam;
 377     }
 378
 379     switch ($type) {
 380         case PARAM_RAW:          // no cleaning at all
 381             return $param;
 382
 383         case PARAM_CLEAN:        // General HTML cleaning, try to use more specific type if possible
 384             if (is_numeric($param)) {
 385                 return $param;
 386             }
 387             $param = stripslashes($param);   // Needed for kses to work fine
 388             $param = clean_text($param);     // Sweep for scripts, etc
 389             return addslashes($param);       // Restore original request parameter slashes
 390
 391         case PARAM_CLEANHTML:    // prepare html fragment for display, do not store it into db!!
 392             $param = stripslashes($param);   // Remove any slashes
 393             $param = clean_text($param);     // Sweep for scripts, etc
 394             return trim($param);
 395
 396         case PARAM_INT:
 397             return (int)$param;  // Convert to integer
 398
 399         case PARAM_NUMBER:
 400             return (float)$param;  // Convert to integer
 401
 402         case PARAM_ALPHA:        // Remove everything not a-z
 403             return eregi_replace('[^a-zA-Z]', '', $param);
 404
 405         case PARAM_ALPHANUM:     // Remove everything not a-zA-Z0-9
 406             return eregi_replace('[^A-Za-z0-9]', '', $param);
 407
 408         case PARAM_ALPHAEXT:     // Remove everything not a-zA-Z/_-
 409             return eregi_replace('[^a-zA-Z/_-]', '', $param);
 410
 411         case PARAM_SEQUENCE:     // Remove everything not 0-9,
 412             return eregi_replace('[^0-9,]', '', $param);
 413
 414         case PARAM_BOOL:         // Convert to 1 or 0
 415             $tempstr = strtolower($param);
 416             if ($tempstr == 'on' or $tempstr == 'yes' ) {
 417                 $param = 1;
 418             } else if ($tempstr == 'off' or $tempstr == 'no') {
 419                 $param = 0;
 420             } else {
 421                 $param = empty($param) ? 0 : 1;
 422             }
 423             return $param;
 424
 425         case PARAM_NOTAGS:       // Strip all tags
 426             return strip_tags($param);
 427
 428         case PARAM_TEXT:    // leave only tags needed for multilang
 429             return clean_param(strip_tags($param, '<lang><span>'), PARAM_CLEAN);
 430
 431         case PARAM_SAFEDIR:      // Remove everything not a-zA-Z0-9_-
 432             return eregi_replace('[^a-zA-Z0-9_-]', '', $param);
 433
 434         case PARAM_CLEANFILE:    // allow only safe characters
 435             return clean_filename($param);
 436
 437         case PARAM_FILE:         // Strip all suspicious characters from filename
 438             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':\\/]', '', $param);
 439             $param = ereg_replace('\.\.+', '', $param);
 440             if($param == '.') {
 441                 $param = '';
 442             }
 443             return $param;
 444
 445         case PARAM_PATH:         // Strip all suspicious characters from file path
 446             $param = str_replace('\\\'', '\'', $param);
 447             $param = str_replace('\\"', '"', $param);
 448             $param = str_replace('\\', '/', $param);
 449             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':]', '', $param);
 450             $param = ereg_replace('\.\.+', '', $param);
 451             $param = ereg_replace('//+', '/', $param);
 452             return ereg_replace('/(\./)+', '/', $param);
 453
 454         case PARAM_HOST:         // allow FQDN or IPv4 dotted quad
 455             preg_replace('/[^\.\d\w-]/','', $param ); // only allowed chars
 456             // match ipv4 dotted quad
 457             if (preg_match('/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/',$param, $match)){
 458                 // confirm values are ok
 459                 if ( $match[0] > 255
 460                      || $match[1] > 255
 461                      || $match[3] > 255
 462                      || $match[4] > 255 ) {
 463                     // hmmm, what kind of dotted quad is this?
 464                     $param = '';
 465                 }
 466             } elseif ( preg_match('/^[\w\d\.-]+$/', $param) // dots, hyphens, numbers
 467                        && !preg_match('/^[\.-]/',  $param) // no leading dots/hyphens
 468                        && !preg_match('/[\.-]$/',  $param) // no trailing dots/hyphens
 469                        ) {
 470                 // all is ok - $param is respected
 471             } else {
 472                 // all is not ok...
 473                 $param='';
 474             }
 475             return $param;
 476
 477         case PARAM_URL:          // allow safe ftp, http, mailto urls
 478             include_once($CFG->dirroot . '/lib/validateurlsyntax.php');
 479             if (!empty($param) && validateUrlSyntax($param, 's?H?S?F?E?u-P-a?I?p?f?q?r?')) {
 480                 // all is ok, param is respected
 481             } else {
 482                 $param =''; // not really ok
 483             }
 484             return $param;
 485
 486         case PARAM_LOCALURL:     // allow http absolute, root relative and relative URLs within wwwroot
 487             $param = clean_param($param, PARAM_URL);
 488             if (!empty($param)) {
 489                 if (preg_match(':^/:', $param)) {
 490                     // root-relative, ok!
 491                 } elseif (preg_match('/^'.preg_quote($CFG->wwwroot, '/').'/i',$param)) {
 492                     // absolute, and matches our wwwroot
 493                 } else {
 494                     // relative - let's make sure there are no tricks
 495                     if (validateUrlSyntax($param, 's-u-P-a-p-f+q?r?')) {
 496                         // looks ok.
 497                     } else {
 498                         $param = '';
 499                     }
 500                 }
 501             }
 502             return $param;
 503
 504         case PARAM_PEM:
 505             $param = trim($param);
 506             // PEM formatted strings may contain letters/numbers and the symbols
 507             // forward slash: /
 508             // plus sign:     +
 509             // equal sign:    =
 510             // , surrounded by BEGIN and END CERTIFICATE prefix and suffixes
 511             if (preg_match('/^-----BEGIN CERTIFICATE-----([\s\w\/\+=]+)-----END CERTIFICATE-----$/', trim($param), $matches)) {
 512                 list($wholething, $body) = $matches;
 513                 unset($wholething, $matches);
 514                 $b64 = clean_param($body, PARAM_BASE64);
 515                 if (!empty($b64)) {
 516                     return "-----BEGIN CERTIFICATE-----\n$b64\n-----END CERTIFICATE-----\n";
 517                 } else {
 518                     return '';
 519                 }
 520             }
 521             return '';
 522
 523         case PARAM_BASE64:
 524             if (!empty($param)) {
 525                 // PEM formatted strings may contain letters/numbers and the symbols
 526                 // forward slash: /
 527                 // plus sign:     +
 528                 // equal sign:    =
 529                 if (0 >= preg_match('/^([\s\w\/\+=]+)$/', trim($param))) {
 530                     return '';
 531                 }
 532                 $lines = preg_split('/[\s]+/', $param, -1, PREG_SPLIT_NO_EMPTY);
 533                 // Each line of base64 encoded data must be 64 characters in
 534                 // length, except for the last line which may be less than (or
 535                 // equal to) 64 characters long.
 536                 for ($i=0, $j=count($lines); $i < $j; $i++) {
 537                     if ($i + 1 == $j) {
 538                         if (64 < strlen($lines[$i])) {
 539                             return '';
 540                         }
 541                         continue;
 542                     }
 543
 544                     if (64 != strlen($lines[$i])) {
 545                         return '';
 546                     }
 547                 }
 548                 return implode("\n",$lines);
 549             } else {
 550                 return '';
 551             }
 552
 553         case PARAM_TAG:
 554             //first fix whitespace
 555             $param = preg_replace('/\s+/', ' ', $param);
 556             //remove blacklisted ASCII ranges of chars - security FIRST - keep only ascii letters, numnbers and spaces
 557             //the result should be safe to be used directly in html and SQL
 558             $param = preg_replace("/[\\000-\\x1f\\x21-\\x2f\\x3a-\\x40\\x5b-\\x60\\x7b-\\x7f]/", '', $param);
 559             //now remove some unicode ranges we do not want
 560             $param = preg_replace("/[\\x{80}-\\x{bf}\\x{d7}\\x{f7}]/u", '', $param);
 561             //cleanup the spaces
 562             $param = preg_replace('/ +/', ' ', $param);
 563             $param = trim($param);
 564             $textlib = textlib_get_instance();
 565             $param = $textlib->substr($param, 0, TAG_MAX_LENGTH);
 566             //numeric tags not allowed
 567             return is_numeric($param) ? '' : $param;
 568
 569         case PARAM_TAGLIST:
 570             $tags = explode(',', $param);
 571             $result = array();
 572             foreach ($tags as $tag) {
 573                 $res = clean_param($tag, PARAM_TAG);
 574                 if ($res != '') {
 575                     $result[] = $res;
 576                 }
 577             }
 578             if ($result) {
 579                 return implode(',', $result);
 580             } else {
 581                 return '';
 582             }
 583
 584         default:                 // throw error, switched parameters in optional_param or another serious problem
 585             error("Unknown parameter type: $type");
 586     }
 587 }
 588
 589
 590
 591 /**
 592  * Set a key in global configuration
 593  *
 594  * Set a key/value pair in both this session's {@link $CFG} global variable
 595  * and in the 'config' database table for future sessions.
 596  *
 597  * Can also be used to update keys for plugin-scoped configs in config_plugin table.
 598  * In that case it doesn't affect $CFG.
 599  *
 600  * @param string $name the key to set
 601  * @param string $value the value to set (without magic quotes)
 602  * @param string $plugin (optional) the plugin scope
 603  * @uses $CFG
 604  * @return bool
 605  */
 606 function set_config($name, $value, $plugin=NULL) {
 607 /// No need for get_config because they are usually always available in $CFG
 608
 609     global $CFG;
 610
 611     if (empty($plugin)) {
 612         $CFG->$name = $value;  // So it's defined for this invocation at least
 613
 614         if (get_field('config', 'name', 'name', $name)) {
 615             return set_field('config', 'value', addslashes($value), 'name', $name);
 616         } else {
 617             $config = new object();
 618             $config->name = $name;
 619             $config->value = addslashes($value);
 620             return insert_record('config', $config);
 621         }
 622     } else { // plugin scope
 623         if ($id = get_field('config_plugins', 'id', 'name', $name, 'plugin', $plugin)) {
 624             return set_field('config_plugins', 'value', addslashes($value), 'id', $id);
 625         } else {
 626             $config = new object();
 627             $config->plugin = addslashes($plugin);
 628             $config->name   = $name;
 629             $config->value  = addslashes($value);
 630             return insert_record('config_plugins', $config);
 631         }
 632     }
 633 }
 634
 635 /**
 636  * Get configuration values from the global config table
 637  * or the config_plugins table.
 638  *
 639  * If called with no parameters it will do the right thing
 640  * generating $CFG safely from the database without overwriting
 641  * existing values.
 642  *
 643  * If called with 2 parameters it will return a $string single
 644  * value or false of the value is not found.
 645  *
 646  * @param string $plugin
 647  * @param string $name
 648  * @uses $CFG
 649  * @return hash-like object or single value
 650  *
 651  */
 652 function get_config($plugin=NULL, $name=NULL) {
 653
 654     global $CFG;
 655
 656     if (!empty($name)) { // the user is asking for a specific value
 657         if (!empty($plugin)) {
 658             return get_field('config_plugins', 'value', 'plugin' , $plugin, 'name', $name);
 659         } else {
 660             return get_field('config', 'value', 'name', $name);
 661         }
 662     }
 663
 664     // the user is after a recordset
 665     if (!empty($plugin)) {
 666         if ($configs=get_records('config_plugins', 'plugin', $plugin, '', 'name,value')) {
 667             $configs = (array)$configs;
 668             $localcfg = array();
 669             foreach ($configs as $config) {
 670                 $localcfg[$config->name] = $config->value;
 671             }
 672             return (object)$localcfg;
 673         } else {
 674             return false;
 675         }
 676     } else {
 677         // this was originally in setup.php
 678         if ($configs = get_records('config')) {
 679             $localcfg = (array)$CFG;
 680             foreach ($configs as $config) {
 681                 if (!isset($localcfg[$config->name])) {
 682                     $localcfg[$config->name] = $config->value;
 683                 } else {
 684                     if ($localcfg[$config->name] != $config->value ) {
 685                         // complain if the DB has a different
 686                         // value than config.php does
 687                         error_log("\$CFG->{$config->name} in config.php ({$localcfg[$config->name]}) overrides database setting ({$config->value})");
 688                     }
 689                 }
 690             }
 691
 692             $localcfg = (object)$localcfg;
 693             return $localcfg;
 694         } else {
 695             // preserve $CFG if DB returns nothing or error
 696             return $CFG;
 697         }
 698
 699     }
 700 }
 701
 702 /**
 703  * Removes a key from global configuration
 704  *
 705  * @param string $name the key to set
 706  * @param string $plugin (optional) the plugin scope
 707  * @uses $CFG
 708  * @return bool
 709  */
 710 function unset_config($name, $plugin=NULL) {
 711
 712     global $CFG;
 713
 714     unset($CFG->$name);
 715
 716     if (empty($plugin)) {
 717         return delete_records('config', 'name', $name);
 718     } else {
 719         return delete_records('config_plugins', 'name', $name, 'plugin', $plugin);
 720     }
 721 }
 722
 723 /**
 724  * Get volatile flags
 725  *
 726  * @param string $type
 727  * @param int    $changedsince
 728  * @return records array
 729  *
 730  */
 731 function get_cache_flags($type, $changedsince=NULL) {
 732
 733     $type = addslashes($type);
 734
 735     $sqlwhere = 'flagtype=\'' . $type . '\' AND expiry >= ' . time();
 736     if ($changedsince !== NULL) {
 737         $changedsince = (int)$changedsince;
 738         $sqlwhere .= ' AND timemodified > ' . $changedsince;
 739     }
 740     $cf = array();
 741     if ($flags=get_records_select('cache_flags', $sqlwhere, '', 'name,value')) {
 742         foreach ($flags as $flag) {
 743             $cf[$flag->name] = $flag->value;
 744         }
 745     }
 746     return $cf;
 747 }
 748
 749
 750 /**
 751  * Set a volatile flag
 752  *
 753  * @param string $type the "type" namespace for the key
 754  * @param string $name the key to set
 755  * @param string $value the value to set (without magic quotes) - NULL will remove the flag
 756  * @param int $expiry (optional) epoch indicating expiry - defaults to now()+ 24hs
 757  * @return bool
 758  */
 759 function set_cache_flag($type, $name, $value, $expiry=NULL) {
 760
 761
 762     $timemodified = time();
 763     if ($expiry===NULL || $expiry < $timemodified) {
 764         $expiry = $timemodified + 24 * 60 * 60;
 765     } else {
 766         $expiry = (int)$expiry;
 767     }
 768
 769     if ($value === NULL) {
 770         return unset_cache_flag($type,$name);
 771     }
 772
 773     $type = addslashes($type);
 774     $name = addslashes($name);
 775     if ($f = get_record('cache_flags', 'name', $name, 'flagtype', $type)) { // this is a potentail problem in DEBUG_DEVELOPER
 776         if ($f->value == $value and $f->expiry == $expiry and $f->timemodified == $timemodified) {
 777             return true; //no need to update; helps rcache too
 778         }
 779         $f->value        = addslashes($value);
 780         $f->expiry       = $expiry;
 781         $f->timemodified = $timemodified;
 782         return update_record('cache_flags', $f);
 783     } else {
 784         $f = new object();
 785         $f->flagtype     = $type;
 786         $f->name         = $name;
 787         $f->value        = addslashes($value);
 788         $f->expiry       = $expiry;
 789         $f->timemodified = $timemodified;
 790         return (bool)insert_record('cache_flags', $f);
 791     }
 792 }
 793
 794 /**
 795  * Removes a single volatile flag
 796  *
 797  * @param string $type the "type" namespace for the key
 798  * @param string $name the key to set
 799  * @uses $CFG
 800  * @return bool
 801  */
 802 function unset_cache_flag($type, $name) {
 803
 804     return delete_records('cache_flags',
 805                           'name', addslashes($name),
 806                           'flagtype', addslashes($type));
 807 }
 808
 809 /**
 810  * Garbage-collect volatile flags
 811  *
 812  */
 813 function gc_cache_flags() {
 814     return delete_records_select('cache_flags', 'expiry < ' . time());
 815 }
 816
 817 /**
 818  * Refresh current $USER session global variable with all their current preferences.
 819  * @uses $USER
 820  */
 821 function reload_user_preferences() {
 822
 823     global $USER;
 824
 825     //reset preference
 826     $USER->preference = array();
 827
 828     if (!isloggedin() or isguestuser()) {
 829         // no pernament storage for not-logged-in user and guest
 830
 831     } else if ($preferences = get_records('user_preferences', 'userid', $USER->id)) {
 832         foreach ($preferences as $preference) {
 833             $USER->preference[$preference->name] = $preference->value;
 834         }
 835     }
 836
 837     return true;
 838 }
 839
 840 /**
 841  * Sets a preference for the current user
 842  * Optionally, can set a preference for a different user object
 843  * @uses $USER
 844  * @todo Add a better description and include usage examples. Add inline links to $USER and user functions in above line.
 845
 846  * @param string $name The key to set as preference for the specified user
 847  * @param string $value The value to set forthe $name key in the specified user's record
 848  * @param int $otheruserid A moodle user ID
 849  * @return bool
 850  */
 851 function set_user_preference($name, $value, $otheruserid=NULL) {
 852
 853     global $USER;
 854
 855     if (!isset($USER->preference)) {
 856         reload_user_preferences();
 857     }
 858
 859     if (empty($name)) {
 860         return false;
 861     }
 862
 863     $nostore = false;
 864
 865     if (empty($otheruserid)){
 866         if (!isloggedin() or isguestuser()) {
 867             $nostore = true;
 868         }
 869         $userid = $USER->id;
 870     } else {
 871         if (isguestuser($otheruserid)) {
 872             $nostore = true;
 873         }
 874         $userid = $otheruserid;
 875     }
 876
 877     $return = true;
 878     if ($nostore) {
 879         // no pernament storage for not-logged-in user and guest
 880
 881     } else if ($preference = get_record('user_preferences', 'userid', $userid, 'name', addslashes($name))) {
 882         if ($preference->value === $value) {
 883             return true;
 884         }
 885         if (!set_field('user_preferences', 'value', addslashes((string)$value), 'id', $preference->id)) {
 886             $return = false;
 887         }
 888
 889     } else {
 890         $preference = new object();
 891         $preference->userid = $userid;
 892         $preference->name   = addslashes($name);
 893         $preference->value  = addslashes((string)$value);
 894         if (!insert_record('user_preferences', $preference)) {
 895             $return = false;
 896         }
 897     }
 898
 899     // update value in USER session if needed
 900     if ($userid == $USER->id) {
 901         $USER->preference[$name] = (string)$value;
 902     }
 903
 904     return $return;
 905 }
 906
 907 /**
 908  * Unsets a preference completely by deleting it from the database
 909  * Optionally, can set a preference for a different user id
 910  * @uses $USER
 911  * @param string  $name The key to unset as preference for the specified user
 912  * @param int $otheruserid A moodle user ID
 913  */
 914 function unset_user_preference($name, $otheruserid=NULL) {
 915
 916     global $USER;
 917
 918     if (!isset($USER->preference)) {
 919         reload_user_preferences();
 920     }
 921
 922     if (empty($otheruserid)){
 923         $userid = $USER->id;
 924     } else {
 925         $userid = $otheruserid;
 926     }
 927
 928     //Delete the preference from $USER if needed
 929     if ($userid == $USER->id) {
 930         unset($USER->preference[$name]);
 931     }
 932
 933     //Then from DB
 934     return delete_records('user_preferences', 'userid', $userid, 'name', addslashes($name));
 935 }
 936
 937
 938 /**
 939  * Sets a whole array of preferences for the current user
 940  * @param array $prefarray An array of key/value pairs to be set
 941  * @param int $otheruserid A moodle user ID
 942  * @return bool
 943  */
 944 function set_user_preferences($prefarray, $otheruserid=NULL) {
 945
 946     if (!is_array($prefarray) or empty($prefarray)) {
 947         return false;
 948     }
 949
 950     $return = true;
 951     foreach ($prefarray as $name => $value) {
 952         // The order is important; test for return is done first
 953         $return = (set_user_preference($name, $value, $otheruserid) && $return);
 954     }
 955     return $return;
 956 }
 957
 958 /**
 959  * If no arguments are supplied this function will return
 960  * all of the current user preferences as an array.
 961  * If a name is specified then this function
 962  * attempts to return that particular preference value.  If
 963  * none is found, then the optional value $default is returned,
 964  * otherwise NULL.
 965  * @param string $name Name of the key to use in finding a preference value
 966  * @param string $default Value to be returned if the $name key is not set in the user preferences
 967  * @param int $otheruserid A moodle user ID
 968  * @uses $USER
 969  * @return string
 970  */
 971 function get_user_preferences($name=NULL, $default=NULL, $otheruserid=NULL) {
 972     global $USER;
 973
 974     if (!isset($USER->preference)) {
 975         reload_user_preferences();
 976     }
 977
 978     if (empty($otheruserid)){
 979         $userid = $USER->id;
 980     } else {
 981         $userid = $otheruserid;
 982     }
 983
 984     if ($userid == $USER->id) {
 985         $preference = $USER->preference;
 986
 987     } else {
 988         $preference = array();
 989         if ($prefdata = get_records('user_preferences', 'userid', $userid)) {
 990             foreach ($prefdata as $pref) {
 991                 $preference[$pref->name] = $pref->value;
 992             }
 993         }
 994     }
 995
 996     if (empty($name)) {
 997         return $preference;            // All values
 998
 999     } else if (array_key_exists($name, $preference)) {
1000         return $preference[$name];    // The single value
1001
1002     } else {
1003         return $default;              // Default value (or NULL)
1004     }
1005 }
1006
1007
1008 /// FUNCTIONS FOR HANDLING TIME ////////////////////////////////////////////
1009
1010 /**
1011  * Given date parts in user time produce a GMT timestamp.
1012  *
1013  * @param int $year The year part to create timestamp of
1014  * @param int $month The month part to create timestamp of
1015  * @param int $day The day part to create timestamp of
1016  * @param int $hour The hour part to create timestamp of
1017  * @param int $minute The minute part to create timestamp of
1018  * @param int $second The second part to create timestamp of
1019  * @param float $timezone ?
1020  * @param bool $applydst ?
1021  * @return int timestamp
1022  * @todo Finish documenting this function
1023  */
1024 function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0, $timezone=99, $applydst=true) {
1025
1026     $timezone = get_user_timezone_offset($timezone);
1027
1028     if (abs($timezone) > 13) {
1029         $time = mktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
1030     } else {
1031         $time = gmmktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
1032         $time = usertime($time, $timezone);
1033         if($applydst) {
1034             $time -= dst_offset_on($time);
1035         }
1036     }
1037
1038     return $time;
1039
1040 }
1041
1042 /**
1043  * Given an amount of time in seconds, returns string
1044  * formatted nicely as weeks, days, hours etc as needed
1045  *
1046  * @uses MINSECS
1047  * @uses HOURSECS
1048  * @uses DAYSECS
1049  * @uses YEARSECS
1050  * @param int $totalsecs ?
1051  * @param array $str ?
1052  * @return string
1053  */
1054  function format_time($totalsecs, $str=NULL) {
1055
1056     $totalsecs = abs($totalsecs);
1057
1058     if (!$str) {  // Create the str structure the slow way
1059         $str->day   = get_string('day');
1060         $str->days  = get_string('days');
1061         $str->hour  = get_string('hour');
1062         $str->hours = get_string('hours');
1063         $str->min   = get_string('min');
1064         $str->mins  = get_string('mins');
1065         $str->sec   = get_string('sec');
1066         $str->secs  = get_string('secs');
1067         $str->year  = get_string('year');
1068         $str->years = get_string('years');
1069     }
1070
1071
1072     $years     = floor($totalsecs/YEARSECS);
1073     $remainder = $totalsecs - ($years*YEARSECS);
1074     $days      = floor($remainder/DAYSECS);
1075     $remainder = $totalsecs - ($days*DAYSECS);
1076     $hours     = floor($remainder/HOURSECS);
1077     $remainder = $remainder - ($hours*HOURSECS);
1078     $mins      = floor($remainder/MINSECS);
1079     $secs      = $remainder - ($mins*MINSECS);
1080
1081     $ss = ($secs == 1)  ? $str->sec  : $str->secs;
1082     $sm = ($mins == 1)  ? $str->min  : $str->mins;
1083     $sh = ($hours == 1) ? $str->hour : $str->hours;
1084     $sd = ($days == 1)  ? $str->day  : $str->days;
1085     $sy = ($years == 1)  ? $str->year  : $str->years;
1086
1087     $oyears = '';
1088     $odays = '';
1089     $ohours = '';
1090     $omins = '';
1091     $osecs = '';
1092
1093     if ($years)  $oyears  = $years .' '. $sy;
1094     if ($days)  $odays  = $days .' '. $sd;
1095     if ($hours) $ohours = $hours .' '. $sh;
1096     if ($mins)  $omins  = $mins .' '. $sm;
1097     if ($secs)  $osecs  = $secs .' '. $ss;
1098
1099     if ($years) return trim($oyears .' '. $odays);
1100     if ($days)  return trim($odays .' '. $ohours);
1101     if ($hours) return trim($ohours .' '. $omins);
1102     if ($mins)  return trim($omins .' '. $osecs);
1103     if ($secs)  return $osecs;
1104     return get_string('now');
1105 }
1106
1107 /**
1108  * Returns a formatted string that represents a date in user time
1109  * <b>WARNING: note that the format is for strftime(), not date().</b>
1110  * Because of a bug in most Windows time libraries, we can't use
1111  * the nicer %e, so we have to use %d which has leading zeroes.
1112  * A lot of the fuss in the function is just getting rid of these leading
1113  * zeroes as efficiently as possible.
1114  *
1115  * If parameter fixday = true (default), then take off leading
1116  * zero from %d, else mantain it.
1117  *
1118  * @uses HOURSECS
1119  * @param  int $date timestamp in GMT
1120  * @param string $format strftime format
1121  * @param float $timezone
1122  * @param bool $fixday If true (default) then the leading
1123  * zero from %d is removed. If false then the leading zero is mantained.
1124  * @return string
1125  */
1126 function userdate($date, $format='', $timezone=99, $fixday = true) {
1127
1128     global $CFG;
1129
1130     if (empty($format)) {
1131         $format = get_string('strftimedaydatetime');
1132     }
1133
1134     if (!empty($CFG->nofixday)) {  // Config.php can force %d not to be fixed.
1135         $fixday = false;
1136     } else if ($fixday) {
1137         $formatnoday = str_replace('%d', 'DD', $format);
1138         $fixday = ($formatnoday != $format);
1139     }
1140
1141     $date += dst_offset_on($date);
1142
1143     $timezone = get_user_timezone_offset($timezone);
1144
1145     if (abs($timezone) > 13) {   /// Server time
1146         if ($fixday) {
1147             $datestring = strftime($formatnoday, $date);
1148             $daystring  = str_replace(' 0', '', strftime(' %d', $date));
1149             $datestring = str_replace('DD', $daystring, $datestring);
1150         } else {
1151             $datestring = strftime($format, $date);
1152         }
1153     } else {
1154         $date += (int)($timezone * 3600);
1155         if ($fixday) {
1156             $datestring = gmstrftime($formatnoday, $date);
1157             $daystring  = str_replace(' 0', '', gmstrftime(' %d', $date));
1158             $datestring = str_replace('DD', $daystring, $datestring);
1159         } else {
1160             $datestring = gmstrftime($format, $date);
1161         }
1162     }
1163
1164 /// If we are running under Windows convert from windows encoding to UTF-8
1165 /// (because it's impossible to specify UTF-8 to fetch locale info in Win32)
1166
1167    if ($CFG->ostype == 'WINDOWS') {
1168        if ($localewincharset = get_string('localewincharset')) {
1169            $textlib = textlib_get_instance();
1170            $datestring = $textlib->convert($datestring, $localewincharset, 'utf-8');
1171        }
1172    }
1173
1174     return $datestring;
1175 }
1176
1177 /**
1178  * Given a $time timestamp in GMT (seconds since epoch),
1179  * returns an array that represents the date in user time
1180  *
1181  * @uses HOURSECS
1182  * @param int $time Timestamp in GMT
1183  * @param float $timezone ?
1184  * @return array An array that represents the date in user time
1185  * @todo Finish documenting this function
1186  */
1187 function usergetdate($time, $timezone=99) {
1188
1189     $timezone = get_user_timezone_offset($timezone);
1190
1191     if (abs($timezone) > 13) {    // Server time
1192         return getdate($time);
1193     }
1194
1195     // There is no gmgetdate so we use gmdate instead
1196     $time += dst_offset_on($time);
1197     $time += intval((float)$timezone * HOURSECS);
1198
1199     $datestring = gmstrftime('%S_%M_%H_%d_%m_%Y_%w_%j_%A_%B', $time);
1200
1201     list(
1202         $getdate['seconds'],
1203         $getdate['minutes'],
1204         $getdate['hours'],
1205         $getdate['mday'],
1206         $getdate['mon'],
1207         $getdate['year'],
1208         $getdate['wday'],
1209         $getdate['yday'],
1210         $getdate['weekday'],
1211         $getdate['month']
1212     ) = explode('_', $datestring);
1213
1214     return $getdate;
1215 }
1216
1217 /**
1218  * Given a GMT timestamp (seconds since epoch), offsets it by
1219  * the timezone.  eg 3pm in India is 3pm GMT - 7 * 3600 seconds
1220  *
1221  * @uses HOURSECS
1222  * @param  int $date Timestamp in GMT
1223  * @param float $timezone
1224  * @return int
1225  */
1226 function usertime($date, $timezone=99) {
1227
1228     $timezone = get_user_timezone_offset($timezone);
1229
1230     if (abs($timezone) > 13) {
1231         return $date;
1232     }
1233     return $date - (int)($timezone * HOURSECS);
1234 }
1235
1236 /**
1237  * Given a time, return the GMT timestamp of the most recent midnight
1238  * for the current user.
1239  *
1240  * @param int $date Timestamp in GMT
1241  * @param float $timezone ?
1242  * @return ?
1243  */
1244 function usergetmidnight($date, $timezone=99) {
1245
1246     $timezone = get_user_timezone_offset($timezone);
1247     $userdate = usergetdate($date, $timezone);
1248
1249     // Time of midnight of this user's day, in GMT
1250     return make_timestamp($userdate['year'], $userdate['mon'], $userdate['mday'], 0, 0, 0, $timezone);
1251
1252 }
1253
1254 /**
1255  * Returns a string that prints the user's timezone
1256  *
1257  * @param float $timezone The user's timezone
1258  * @return string
1259  */
1260 function usertimezone($timezone=99) {
1261
1262     $tz = get_user_timezone($timezone);
1263
1264     if (!is_float($tz)) {
1265         return $tz;
1266     }
1267
1268     if(abs($tz) > 13) { // Server time
1269         return get_string('serverlocaltime');
1270     }
1271
1272     if($tz == intval($tz)) {
1273         // Don't show .0 for whole hours
1274         $tz = intval($tz);
1275     }
1276
1277     if($tz == 0) {
1278         return 'GMT';
1279     }
1280     else if($tz > 0) {
1281         return 'GMT+'.$tz;
1282     }
1283     else {
1284         return 'GMT'.$tz;
1285     }
1286
1287 }
1288
1289 /**
1290  * Returns a float which represents the user's timezone difference from GMT in hours
1291  * Checks various settings and picks the most dominant of those which have a value
1292  *
1293  * @uses $CFG
1294  * @uses $USER
1295  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1296  * @return int
1297  */
1298 function get_user_timezone_offset($tz = 99) {
1299
1300     global $USER, $CFG;
1301
1302     $tz = get_user_timezone($tz);
1303
1304     if (is_float($tz)) {
1305         return $tz;
1306     } else {
1307         $tzrecord = get_timezone_record($tz);
1308         if (empty($tzrecord)) {
1309             return 99.0;
1310         }
1311         return (float)$tzrecord->gmtoff / HOURMINS;
1312     }
1313 }
1314
1315 /**
1316  * Returns a float or a string which denotes the user's timezone
1317  * 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)
1318  * means that for this timezone there are also DST rules to be taken into account
1319  * Checks various settings and picks the most dominant of those which have a value
1320  *
1321  * @uses $USER
1322  * @uses $CFG
1323  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1324  * @return mixed
1325  */
1326 function get_user_timezone($tz = 99) {
1327     global $USER, $CFG;
1328
1329     $timezones = array(
1330         $tz,
1331         isset($CFG->forcetimezone) ? $CFG->forcetimezone : 99,
1332         isset($USER->timezone) ? $USER->timezone : 99,
1333         isset($CFG->timezone) ? $CFG->timezone : 99,
1334         );
1335
1336     $tz = 99;
1337
1338     while(($tz == '' || $tz == 99) && $next = each($timezones)) {
1339         $tz = $next['value'];
1340     }
1341
1342     return is_numeric($tz) ? (float) $tz : $tz;
1343 }
1344
1345 /**
1346  * ?
1347  *
1348  * @uses $CFG
1349  * @uses $db
1350  * @param string $timezonename ?
1351  * @return object
1352  */
1353 function get_timezone_record($timezonename) {
1354     global $CFG, $db;
1355     static $cache = NULL;
1356
1357     if ($cache === NULL) {
1358         $cache = array();
1359     }
1360
1361     if (isset($cache[$timezonename])) {
1362         return $cache[$timezonename];
1363     }
1364
1365     return $cache[$timezonename] = get_record_sql('SELECT * FROM '.$CFG->prefix.'timezone
1366                                       WHERE name = '.$db->qstr($timezonename).' ORDER BY year DESC', true);
1367 }
1368
1369 /**
1370  * ?
1371  *
1372  * @uses $CFG
1373  * @uses $USER
1374  * @param ? $fromyear ?
1375  * @param ? $to_year ?
1376  * @return bool
1377  */
1378 function calculate_user_dst_table($from_year = NULL, $to_year = NULL) {
1379     global $CFG, $SESSION;
1380
1381     $usertz = get_user_timezone();
1382
1383     if (is_float($usertz)) {
1384         // Trivial timezone, no DST
1385         return false;
1386     }
1387
1388     if (!empty($SESSION->dst_offsettz) && $SESSION->dst_offsettz != $usertz) {
1389         // We have precalculated values, but the user's effective TZ has changed in the meantime, so reset
1390         unset($SESSION->dst_offsets);
1391         unset($SESSION->dst_range);
1392     }
1393
1394     if (!empty($SESSION->dst_offsets) && empty($from_year) && empty($to_year)) {
1395         // Repeat calls which do not request specific year ranges stop here, we have already calculated the table
1396         // This will be the return path most of the time, pretty light computationally
1397         return true;
1398     }
1399
1400     // Reaching here means we either need to extend our table or create it from scratch
1401
1402     // Remember which TZ we calculated these changes for
1403     $SESSION->dst_offsettz = $usertz;
1404
1405     if(empty($SESSION->dst_offsets)) {
1406         // If we 're creating from scratch, put the two guard elements in there
1407         $SESSION->dst_offsets = array(1 => NULL, 0 => NULL);
1408     }
1409     if(empty($SESSION->dst_range)) {
1410         // If creating from scratch
1411         $from = max((empty($from_year) ? intval(date('Y')) - 3 : $from_year), 1971);
1412         $to   = min((empty($to_year)   ? intval(date('Y')) + 3 : $to_year),   2035);
1413
1414         // Fill in the array with the extra years we need to process
1415         $yearstoprocess = array();
1416         for($i = $from; $i <= $to; ++$i) {
1417             $yearstoprocess[] = $i;
1418         }
1419
1420         // Take note of which years we have processed for future calls
1421         $SESSION->dst_range = array($from, $to);
1422     }
1423     else {
1424         // If needing to extend the table, do the same
1425         $yearstoprocess = array();
1426
1427         $from = max((empty($from_year) ? $SESSION->dst_range[0] : $from_year), 1971);
1428         $to   = min((empty($to_year)   ? $SESSION->dst_range[1] : $to_year),   2035);
1429
1430         if($from < $SESSION->dst_range[0]) {
1431             // Take note of which years we need to process and then note that we have processed them for future calls
1432             for($i = $from; $i < $SESSION->dst_range[0]; ++$i) {
1433                 $yearstoprocess[] = $i;
1434             }
1435             $SESSION->dst_range[0] = $from;
1436         }
1437         if($to > $SESSION->dst_range[1]) {
1438             // Take note of which years we need to process and then note that we have processed them for future calls
1439             for($i = $SESSION->dst_range[1] + 1; $i <= $to; ++$i) {
1440                 $yearstoprocess[] = $i;
1441             }
1442             $SESSION->dst_range[1] = $to;
1443         }
1444     }
1445
1446     if(empty($yearstoprocess)) {
1447         // This means that there was a call requesting a SMALLER range than we have already calculated
1448         return true;
1449     }
1450
1451     // From now on, we know that the array has at least the two guard elements, and $yearstoprocess has the years we need
1452     // Also, the array is sorted in descending timestamp order!
1453
1454     // Get DB data
1455     $presetrecords = get_records('timezone', 'name', $usertz, 'year DESC', 'year, gmtoff, dstoff, dst_month, dst_startday, dst_weekday, dst_skipweeks, dst_time, std_month, std_startday, std_weekday, std_skipweeks, std_time');
1456     if(empty($presetrecords)) {
1457         return false;
1458     }
1459
1460     // Remove ending guard (first element of the array)
1461     reset($SESSION->dst_offsets);
1462     unset($SESSION->dst_offsets[key($SESSION->dst_offsets)]);
1463
1464     // Add all required change timestamps
1465     foreach($yearstoprocess as $y) {
1466         // Find the record which is in effect for the year $y
1467         foreach($presetrecords as $year => $preset) {
1468             if($year <= $y) {
1469                 break;
1470             }
1471         }
1472
1473         $changes = dst_changes_for_year($y, $preset);
1474
1475         if($changes === NULL) {
1476             continue;
1477         }
1478         if($changes['dst'] != 0) {
1479             $SESSION->dst_offsets[$changes['dst']] = $preset->dstoff * MINSECS;
1480         }
1481         if($changes['std'] != 0) {
1482             $SESSION->dst_offsets[$changes['std']] = 0;
1483         }
1484     }
1485
1486     // Put in a guard element at the top
1487     $maxtimestamp = max(array_keys($SESSION->dst_offsets));
1488     $SESSION->dst_offsets[($maxtimestamp + DAYSECS)] = NULL; // DAYSECS is arbitrary, any "small" number will do
1489
1490     // Sort again
1491     krsort($SESSION->dst_offsets);
1492
1493     return true;
1494 }
1495
1496 function dst_changes_for_year($year, $timezone) {
1497
1498     if($timezone->dst_startday == 0 && $timezone->dst_weekday == 0 && $timezone->std_startday == 0 && $timezone->std_weekday == 0) {
1499         return NULL;
1500     }
1501
1502     $monthdaydst = find_day_in_month($timezone->dst_startday, $timezone->dst_weekday, $timezone->dst_month, $year);
1503     $monthdaystd = find_day_in_month($timezone->std_startday, $timezone->std_weekday, $timezone->std_month, $year);
1504
1505     list($dst_hour, $dst_min) = explode(':', $timezone->dst_time);
1506     list($std_hour, $std_min) = explode(':', $timezone->std_time);
1507
1508     $timedst = make_timestamp($year, $timezone->dst_month, $monthdaydst, 0, 0, 0, 99, false);
1509     $timestd = make_timestamp($year, $timezone->std_month, $monthdaystd, 0, 0, 0, 99, false);
1510
1511     // Instead of putting hour and minute in make_timestamp(), we add them afterwards.
1512     // This has the advantage of being able to have negative values for hour, i.e. for timezones
1513     // where GMT time would be in the PREVIOUS day than the local one on which DST changes.
1514
1515     $timedst += $dst_hour * HOURSECS + $dst_min * MINSECS;
1516     $timestd += $std_hour * HOURSECS + $std_min * MINSECS;
1517
1518     return array('dst' => $timedst, 0 => $timedst, 'std' => $timestd, 1 => $timestd);
1519 }
1520
1521 // $time must NOT be compensated at all, it has to be a pure timestamp
1522 function dst_offset_on($time) {
1523     global $SESSION;
1524
1525     if(!calculate_user_dst_table() || empty($SESSION->dst_offsets)) {
1526         return 0;
1527     }
1528
1529     reset($SESSION->dst_offsets);
1530     while(list($from, $offset) = each($SESSION->dst_offsets)) {
1531         if($from <= $time) {
1532             break;
1533         }
1534     }
1535
1536     // This is the normal return path
1537     if($offset !== NULL) {
1538         return $offset;
1539     }
1540
1541     // Reaching this point means we haven't calculated far enough, do it now:
1542     // Calculate extra DST changes if needed and recurse. The recursion always
1543     // moves toward the stopping condition, so will always end.
1544
1545     if($from == 0) {
1546         // We need a year smaller than $SESSION->dst_range[0]
1547         if($SESSION->dst_range[0] == 1971) {
1548             return 0;
1549         }
1550         calculate_user_dst_table($SESSION->dst_range[0] - 5, NULL);
1551         return dst_offset_on($time);
1552     }
1553     else {
1554         // We need a year larger than $SESSION->dst_range[1]
1555         if($SESSION->dst_range[1] == 2035) {
1556             return 0;
1557         }
1558         calculate_user_dst_table(NULL, $SESSION->dst_range[1] + 5);
1559         return dst_offset_on($time);
1560     }
1561 }
1562
1563 function find_day_in_month($startday, $weekday, $month, $year) {
1564
1565     $daysinmonth = days_in_month($month, $year);
1566
1567     if($weekday == -1) {
1568         // Don't care about weekday, so return:
1569         //    abs($startday) if $startday != -1
1570         //    $daysinmonth otherwise
1571         return ($startday == -1) ? $daysinmonth : abs($startday);
1572     }
1573
1574     // From now on we 're looking for a specific weekday
1575
1576     // Give "end of month" its actual value, since we know it
1577     if($startday == -1) {
1578         $startday = -1 * $daysinmonth;
1579     }
1580
1581     // Starting from day $startday, the sign is the direction
1582
1583     if($startday < 1) {
1584
1585         $startday = abs($startday);
1586         $lastmonthweekday  = strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1587
1588         // This is the last such weekday of the month
1589         $lastinmonth = $daysinmonth + $weekday - $lastmonthweekday;
1590         if($lastinmonth > $daysinmonth) {
1591             $lastinmonth -= 7;
1592         }
1593
1594         // Find the first such weekday <= $startday
1595         while($lastinmonth > $startday) {
1596             $lastinmonth -= 7;
1597         }
1598
1599         return $lastinmonth;
1600
1601     }
1602     else {
1603
1604         $indexweekday = strftime('%w', mktime(12, 0, 0, $month, $startday, $year, 0));
1605
1606         $diff = $weekday - $indexweekday;
1607         if($diff < 0) {
1608             $diff += 7;
1609         }
1610
1611         // This is the first such weekday of the month equal to or after $startday
1612         $firstfromindex = $startday + $diff;
1613
1614         return $firstfromindex;
1615
1616     }
1617 }
1618
1619 /**
1620  * Calculate the number of days in a given month
1621  *
1622  * @param int $month The month whose day count is sought
1623  * @param int $year The year of the month whose day count is sought
1624  * @return int
1625  */
1626 function days_in_month($month, $year) {
1627    return intval(date('t', mktime(12, 0, 0, $month, 1, $year, 0)));
1628 }
1629
1630 /**
1631  * Calculate the position in the week of a specific calendar day
1632  *
1633  * @param int $day The day of the date whose position in the week is sought
1634  * @param int $month The month of the date whose position in the week is sought
1635  * @param int $year The year of the date whose position in the week is sought
1636  * @return int
1637  */
1638 function dayofweek($day, $month, $year) {
1639     // I wonder if this is any different from
1640     // strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1641     return intval(date('w', mktime(12, 0, 0, $month, $day, $year, 0)));
1642 }
1643
1644 /// USER AUTHENTICATION AND LOGIN ////////////////////////////////////////
1645
1646 /**
1647  * Makes sure that $USER->sesskey exists, if $USER itself exists. It sets a new sesskey
1648  * if one does not already exist, but does not overwrite existing sesskeys. Returns the
1649  * sesskey string if $USER exists, or boolean false if not.
1650  *
1651  * @uses $USER
1652  * @return string
1653  */
1654 function sesskey() {
1655     global $USER;
1656
1657     if(!isset($USER)) {
1658         return false;
1659     }
1660
1661     if (empty($USER->sesskey)) {
1662         $USER->sesskey = random_string(10);
1663     }
1664
1665     return $USER->sesskey;
1666 }
1667
1668
1669 /**
1670  * For security purposes, this function will check that the currently
1671  * given sesskey (passed as a parameter to the script or this function)
1672  * matches that of the current user.
1673  *
1674  * @param string $sesskey optionally provided sesskey
1675  * @return bool
1676  */
1677 function confirm_sesskey($sesskey=NULL) {
1678     global $USER;
1679
1680     if (!empty($USER->ignoresesskey) || !empty($CFG->ignoresesskey)) {
1681         return true;
1682     }
1683
1684     if (empty($sesskey)) {
1685         $sesskey = required_param('sesskey', PARAM_RAW);  // Check script parameters
1686     }
1687
1688     if (!isset($USER->sesskey)) {
1689         return false;
1690     }
1691
1692     return ($USER->sesskey === $sesskey);
1693 }
1694
1695 /**
1696  * Setup all global $CFG course variables, set locale and also themes
1697  * This function can be used on pages that do not require login instead of require_login()
1698  *
1699  * @param mixed $courseorid id of the course or course object
1700  */
1701 function course_setup($courseorid=0) {
1702     global $COURSE, $CFG, $SITE;
1703
1704 /// Redefine global $COURSE if needed
1705     if (empty($courseorid)) {
1706         // no change in global $COURSE - for backwards compatibiltiy
1707         // if require_rogin() used after require_login($courseid);
1708     } else if (is_object($courseorid)) {
1709         $COURSE = clone($courseorid);
1710     } else {
1711         global $course; // used here only to prevent repeated fetching from DB - may be removed later
1712         if (!empty($course->id) and $course->id == SITEID) {
1713             $COURSE = clone($SITE);
1714         } else if (!empty($course->id) and $course->id == $courseorid) {
1715             $COURSE = clone($course);
1716         } else {
1717             if (!$COURSE = get_record('course', 'id', $courseorid)) {
1718                 error('Invalid course ID');
1719             }
1720         }
1721     }
1722
1723 /// set locale and themes
1724     moodle_setlocale();
1725     theme_setup();
1726
1727 }
1728
1729 /**
1730  * This function checks that the current user is logged in and has the
1731  * required privileges
1732  *
1733  * This function checks that the current user is logged in, and optionally
1734  * whether they are allowed to be in a particular course and view a particular
1735  * course module.
1736  * If they are not logged in, then it redirects them to the site login unless
1737  * $autologinguest is set and {@link $CFG}->autologinguests is set to 1 in which
1738  * case they are automatically logged in as guests.
1739  * If $courseid is given and the user is not enrolled in that course then the
1740  * user is redirected to the course enrolment page.
1741  * If $cm is given and the coursemodule is hidden and the user is not a teacher
1742  * in the course then the user is redirected to the course home page.
1743  *
1744  * @uses $CFG
1745  * @uses $SESSION
1746  * @uses $USER
1747  * @uses $FULLME
1748  * @uses SITEID
1749  * @uses $COURSE
1750  * @param mixed $courseorid id of the course or course object
1751  * @param bool $autologinguest
1752  * @param object $cm course module object
1753  */
1754 function require_login($courseorid=0, $autologinguest=true, $cm=null) {
1755
1756     global $CFG, $SESSION, $USER, $COURSE, $FULLME;
1757
1758 /// setup global $COURSE, themes, language and locale
1759     course_setup($courseorid);
1760
1761 /// If the user is not even logged in yet then make sure they are
1762     if (!isloggedin()) {
1763         //NOTE: $USER->site check was obsoleted by session test cookie,
1764         //      $USER->confirmed test is in login/index.php
1765         $SESSION->wantsurl = $FULLME;
1766         if (!empty($_SERVER['HTTP_REFERER'])) {
1767             $SESSION->fromurl  = $_SERVER['HTTP_REFERER'];
1768         }
1769         if ($autologinguest and !empty($CFG->guestloginbutton) and !empty($CFG->autologinguests) and ($COURSE->id == SITEID or $COURSE->guest) ) {
1770             $loginguest = '?loginguest=true';
1771         } else {
1772             $loginguest = '';
1773         }
1774         if (empty($CFG->loginhttps) or $loginguest) { //do not require https for guest logins
1775             redirect($CFG->wwwroot .'/login/index.php'. $loginguest);
1776         } else {
1777             $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1778             redirect($wwwroot .'/login/index.php');
1779         }
1780         exit;
1781     }
1782
1783 /// loginas as redirection if needed
1784     if ($COURSE->id != SITEID and !empty($USER->realuser)) {
1785         if ($USER->loginascontext->contextlevel == CONTEXT_COURSE) {
1786             if ($USER->loginascontext->instanceid != $COURSE->id) {
1787                 print_error('loginasonecourse', '', $CFG->wwwroot.'/course/view.php?id='.$USER->loginascontext->instanceid);
1788             }
1789         }
1790     }
1791
1792
1793 /// check whether the user should be changing password (but only if it is REALLY them)
1794     if (get_user_preferences('auth_forcepasswordchange') && empty($USER->realuser)) {
1795         $userauth = get_auth_plugin($USER->auth);
1796         if ($userauth->can_change_password()) {
1797             $SESSION->wantsurl = $FULLME;
1798             if ($changeurl = $userauth->change_password_url()) {
1799                 //use plugin custom url
1800                 redirect($changeurl);
1801             } else {
1802                 //use moodle internal method
1803                 if (empty($CFG->loginhttps)) {
1804                     redirect($CFG->wwwroot .'/login/change_password.php');
1805                 } else {
1806                     $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1807                     redirect($wwwroot .'/login/change_password.php');
1808                 }
1809             }
1810         } else {
1811             error(get_string('nopasswordchangeforced', 'auth'));
1812         }
1813     }
1814
1815 /// Check that the user account is properly set up
1816     if (user_not_fully_set_up($USER)) {
1817         $SESSION->wantsurl = $FULLME;
1818         redirect($CFG->wwwroot .'/user/edit.php?id='. $USER->id .'&amp;course='. SITEID);
1819     }
1820
1821 /// Make sure current IP matches the one for this session (if required)
1822     if (!empty($CFG->tracksessionip)) {
1823         if ($USER->sessionIP != md5(getremoteaddr())) {
1824             error(get_string('sessionipnomatch', 'error'));
1825         }
1826     }
1827
1828 /// Make sure the USER has a sesskey set up.  Used for checking script parameters.
1829     sesskey();
1830
1831     // Check that the user has agreed to a site policy if there is one
1832     if (!empty($CFG->sitepolicy)) {
1833         if (!$USER->policyagreed) {
1834             $SESSION->wantsurl = $FULLME;
1835             redirect($CFG->wwwroot .'/user/policy.php');
1836         }
1837     }
1838
1839     // Fetch the system context, we are going to use it a lot.
1840     $sysctx = get_context_instance(CONTEXT_SYSTEM);
1841
1842 /// If the site is currently under maintenance, then print a message
1843     if (!has_capability('moodle/site:config', $sysctx)) {
1844         if (file_exists($CFG->dataroot.'/'.SITEID.'/maintenance.html')) {
1845             print_maintenance_message();
1846             exit;
1847         }
1848     }
1849
1850 /// groupmembersonly access control
1851     if (!empty($CFG->enablegroupings) and $cm and $cm->groupmembersonly and !has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
1852         if (isguestuser() or !groups_has_membership($cm)) {
1853             error(get_string('groupmembersonlyerror', 'group'), $CFG->wwwroot.'/course/view.php?id='.$cm->course);
1854         }
1855     }
1856
1857     // Fetch the course context, and prefetch its child contexts
1858     if (!isset($COURSE->context)) {
1859         if ( ! $COURSE->context = get_context_instance(CONTEXT_COURSE, $COURSE->id) ) {
1860             print_error('nocontext');
1861         }
1862     }
1863     if ($COURSE->id == SITEID) {
1864         /// Eliminate hidden site activities straight away
1865         if (!empty($cm) && !$cm->visible
1866             && !has_capability('moodle/course:viewhiddenactivities', $COURSE->context)) {
1867             redirect($CFG->wwwroot, get_string('activityiscurrentlyhidden'));
1868         }
1869         return;
1870
1871     } else {
1872
1873         /// Check if the user can be in a particular course
1874         if (empty($USER->access['rsw'][$COURSE->context->path])) {
1875             //
1876             // Spaghetti logic construct
1877             //
1878             // - able to view course?
1879             // - able to view category?
1880             // => if either is missing, course is hidden from this user
1881             //
1882             // It's carefully ordered so we run the cheap checks first, and the
1883             // more costly checks last...
1884             //
1885             if (! (($COURSE->visible || has_capability('moodle/course:viewhiddencourses', $COURSE->context))
1886                    && (course_parent_visible($COURSE)) || has_capability('moodle/course:viewhiddencourses',
1887                                                                         get_context_instance(CONTEXT_COURSECAT,
1888                                                                                              $COURSE->category)))) {
1889                 print_header_simple();
1890                 notice(get_string('coursehidden'), $CFG->wwwroot .'/');
1891             }
1892         }
1893
1894     /// Non-guests who don't currently have access, check if they can be allowed in as a guest
1895
1896         if ($USER->username != 'guest' and !has_capability('moodle/course:view', $COURSE->context)) {
1897             if ($COURSE->guest == 1) {
1898                  // Temporarily assign them guest role for this context, if it fails later user is asked to enrol
1899                  $USER->access = load_temp_role($COURSE->context, $CFG->guestroleid, $USER->access);
1900             }
1901         }
1902
1903     /// If the user is a guest then treat them according to the course policy about guests
1904
1905         if (has_capability('moodle/legacy:guest', $COURSE->context, NULL, false)) {
1906             switch ($COURSE->guest) {    /// Check course policy about guest access
1907
1908                 case 1:    /// Guests always allowed
1909                     if (!has_capability('moodle/course:view', $COURSE->context)) {    // Prohibited by capability
1910                         print_header_simple();
1911                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1912                     }
1913                     if (!empty($cm) and !$cm->visible) { // Not allowed to see module, send to course page
1914                         redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course,
1915                                  get_string('activityiscurrentlyhidden'));
1916                     }
1917
1918                     return;   // User is allowed to see this course
1919
1920                     break;
1921
1922                 case 2:    /// Guests allowed with key
1923                     if (!empty($USER->enrolkey[$COURSE->id])) {   // Set by enrol/manual/enrol.php
1924                         return true;
1925                     }
1926                     //  otherwise drop through to logic below (--> enrol.php)
1927                     break;
1928
1929                 default:    /// Guests not allowed
1930                     $strloggedinasguest = get_string('loggedinasguest');
1931                     print_header_simple('', '',
1932                             build_navigation(array(array('name' => $strloggedinasguest, 'link' => null, 'type' => 'misc'))));
1933                     if (empty($USER->access['rsw'][$COURSE->context->path])) {  // Normal guest
1934                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1935                     } else {
1936                         notify(get_string('guestsnotallowed', '', format_string($COURSE->fullname)));
1937                         echo '<div class="notifyproblem">'.switchroles_form($COURSE->id).'</div>';
1938                         print_footer($COURSE);
1939                         exit;
1940                     }
1941                     break;
1942             }
1943
1944     /// For non-guests, check if they have course view access
1945
1946         } else if (has_capability('moodle/course:view', $COURSE->context)) {
1947             if (!empty($USER->realuser)) {   // Make sure the REAL person can also access this course
1948                 if (!has_capability('moodle/course:view', $COURSE->context, $USER->realuser)) {
1949                     print_header_simple();
1950                     notice(get_string('studentnotallowed', '', fullname($USER, true)), $CFG->wwwroot .'/');
1951                 }
1952             }
1953
1954         /// Make sure they can read this activity too, if specified
1955
1956             if (!empty($cm) and !$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $COURSE->context)) {
1957                 redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course, get_string('activityiscurrentlyhidden'));
1958             }
1959             return;   // User is allowed to see this course
1960
1961         }
1962
1963
1964     /// Currently not enrolled in the course, so see if they want to enrol
1965         $SESSION->wantsurl = $FULLME;
1966         redirect($CFG->wwwroot .'/course/enrol.php?id='. $COURSE->id);
1967         die;
1968     }
1969 }
1970
1971
1972
1973 /**
1974  * This function just makes sure a user is logged out.
1975  *
1976  * @uses $CFG
1977  * @uses $USER
1978  */
1979 function require_logout() {
1980
1981     global $USER, $CFG, $SESSION;
1982
1983     if (isloggedin()) {
1984         add_to_log(SITEID, "user", "logout", "view.php?id=$USER->id&course=".SITEID, $USER->id, 0, $USER->id);
1985
1986         $authsequence = get_enabled_auth_plugins(); // auths, in sequence
1987         foreach($authsequence as $authname) {
1988             $authplugin = get_auth_plugin($authname);
1989             $authplugin->prelogout_hook();
1990         }
1991     }
1992
1993     if (ini_get_bool("register_globals") and check_php_version("4.3.0")) {
1994         // This method is just to try to avoid silly warnings from PHP 4.3.0
1995         session_unregister("USER");
1996         session_unregister("SESSION");
1997     }
1998
1999     // Initialize variable to pass-by-reference to headers_sent(&$file, &$line)
2000     $file = $line = null;
2001     if (headers_sent($file, $line)) {
2002         error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
2003         error_log('Headers were already sent in file: '.$file.' on line '.$line);
2004     } else {
2005         setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
2006     }
2007
2008     unset($_SESSION['USER']);
2009     unset($_SESSION['SESSION']);
2010
2011     unset($SESSION);
2012     unset($USER);
2013
2014 }
2015
2016 /**
2017  * This is a weaker version of {@link require_login()} which only requires login
2018  * when called from within a course rather than the site page, unless
2019  * the forcelogin option is turned on.
2020  *
2021  * @uses $CFG
2022  * @param mixed $courseorid The course object or id in question
2023  * @param bool $autologinguest Allow autologin guests if that is wanted
2024  * @param object $cm Course activity module if known
2025  */
2026 function require_course_login($courseorid, $autologinguest=true, $cm=null) {
2027     global $CFG;
2028     if (!empty($CFG->forcelogin)) {
2029         // login required for both SITE and courses
2030         require_login($courseorid, $autologinguest, $cm);
2031
2032     } else if (!empty($cm) and !$cm->visible) {
2033         // always login for hidden activities
2034         require_login($courseorid, $autologinguest, $cm);
2035
2036     } else if ((is_object($courseorid) and $courseorid->id == SITEID)
2037           or (!is_object($courseorid) and $courseorid == SITEID)) {
2038         //login for SITE not required
2039         return;
2040
2041     } else {
2042         // course login always required
2043         require_login($courseorid, $autologinguest, $cm);
2044     }
2045 }
2046
2047 /**
2048  * Require key login. Function terminates with error if key not found or incorrect.
2049  * @param string $script unique script identifier
2050  * @param int $instance optional instance id
2051  */
2052 function require_user_key_login($script, $instance=null) {
2053     global $nomoodlecookie, $USER, $SESSION, $CFG;
2054
2055     if (empty($nomoodlecookie)) {
2056         error('Incorrect use of require_key_login() - session cookies must be disabled!');
2057     }
2058
2059 /// extra safety
2060     @session_write_close();
2061
2062     $keyvalue = required_param('key', PARAM_ALPHANUM);
2063
2064     if (!$key = get_record('user_private_key', 'script', $script, 'value', $keyvalue, 'instance', $instance)) {
2065         error('Incorrect key');
2066     }
2067
2068     if (!empty($key->validuntil) and $key->validuntil < time()) {
2069         error('Expired key');
2070     }
2071
2072     if ($key->iprestriction) {
2073         $remoteaddr = getremoteaddr();
2074         if ($remoteaddr == '' or !address_in_subnet($remoteaddr, $key->iprestriction)) {
2075             error('Client IP address mismatch');
2076         }
2077     }
2078
2079     if (!$user = get_record('user', 'id', $key->userid)) {
2080         error('Incorrect user record');
2081     }
2082
2083 /// emulate normal session
2084     $SESSION = new object();
2085     $USER    = $user;
2086
2087 /// note we are not using normal login
2088     if (!defined('USER_KEY_LOGIN')) {
2089         define('USER_KEY_LOGIN', true);
2090     }
2091
2092     load_all_capabilities();
2093
2094 /// return isntance id - it might be empty
2095     return $key->instance;
2096 }
2097
2098 /**
2099  * Creates a new private user access key.
2100  * @param string $script unique target identifier
2101  * @param int $userid
2102  * @param instance $int optional instance id
2103  * @param string $iprestriction optional ip restricted access
2104  * @param timestamp $validuntil key valid only until given data
2105  * @return string access key value
2106  */
2107 function create_user_key($script, $userid, $instance=null, $iprestriction=null, $validuntil=null) {
2108     $key = new object();
2109     $key->script        = $script;
2110     $key->userid        = $userid;
2111     $key->instance      = $instance;
2112     $key->iprestriction = $iprestriction;
2113     $key->validuntil    = $validuntil;
2114     $key->timecreated   = time();
2115
2116     $key->value         = md5($userid.'_'.time().random_string(40)); // something long and unique
2117     while (record_exists('user_private_key', 'value', $key->value)) {
2118         // must be unique
2119         $key->value     = md5($userid.'_'.time().random_string(40));
2120     }
2121
2122     if (!insert_record('user_private_key', $key)) {
2123         error('Can not insert new key');
2124     }
2125
2126     return $key->value;
2127 }
2128
2129 /**
2130  * Modify the user table by setting the currently logged in user's
2131  * last login to now.
2132  *
2133  * @uses $USER
2134  * @return bool
2135  */
2136 function update_user_login_times() {
2137     global $USER;
2138
2139     $user = new object();
2140     $USER->lastlogin = $user->lastlogin = $USER->currentlogin;
2141     $USER->currentlogin = $user->lastaccess = $user->currentlogin = time();
2142
2143     $user->id = $USER->id;
2144
2145     return update_record('user', $user);
2146 }
2147
2148 /**
2149  * Determines if a user has completed setting up their account.
2150  *
2151  * @param user $user A {@link $USER} object to test for the existance of a valid name and email
2152  * @return bool
2153  */
2154 function user_not_fully_set_up($user) {
2155     return ($user->username != 'guest' and (empty($user->firstname) or empty($user->lastname) or empty($user->email) or over_bounce_threshold($user)));
2156 }
2157
2158 function over_bounce_threshold($user) {
2159
2160     global $CFG;
2161
2162     if (empty($CFG->handlebounces)) {
2163         return false;
2164     }
2165     // set sensible defaults
2166     if (empty($CFG->minbounces)) {
2167         $CFG->minbounces = 10;
2168     }
2169     if (empty($CFG->bounceratio)) {
2170         $CFG->bounceratio = .20;
2171     }
2172     $bouncecount = 0;
2173     $sendcount = 0;
2174     if ($bounce = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2175         $bouncecount = $bounce->value;
2176     }
2177     if ($send = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2178         $sendcount = $send->value;
2179     }
2180     return ($bouncecount >= $CFG->minbounces && $bouncecount/$sendcount >= $CFG->bounceratio);
2181 }
2182
2183 /**
2184  * @param $user - object containing an id
2185  * @param $reset - will reset the count to 0
2186  */
2187 function set_send_count($user,$reset=false) {
2188     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2189         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2190         update_record('user_preferences',$pref);
2191     }
2192     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2193         // make a new one
2194         $pref->name = 'email_send_count';
2195         $pref->value = 1;
2196         $pref->userid = $user->id;
2197         insert_record('user_preferences',$pref, false);
2198     }
2199 }
2200
2201 /**
2202 * @param $user - object containing an id
2203  * @param $reset - will reset the count to 0
2204  */
2205 function set_bounce_count($user,$reset=false) {
2206     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2207         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2208         update_record('user_preferences',$pref);
2209     }
2210     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2211         // make a new one
2212         $pref->name = 'email_bounce_count';
2213         $pref->value = 1;
2214         $pref->userid = $user->id;
2215         insert_record('user_preferences',$pref, false);
2216     }
2217 }
2218
2219 /**
2220  * Keeps track of login attempts
2221  *
2222  * @uses $SESSION
2223  */
2224 function update_login_count() {
2225
2226     global $SESSION;
2227
2228     $max_logins = 10;
2229
2230     if (empty($SESSION->logincount)) {
2231         $SESSION->logincount = 1;
2232     } else {
2233         $SESSION->logincount++;
2234     }
2235
2236     if ($SESSION->logincount > $max_logins) {
2237         unset($SESSION->wantsurl);
2238         error(get_string('errortoomanylogins'));
2239     }
2240 }
2241
2242 /**
2243  * Resets login attempts
2244  *
2245  * @uses $SESSION
2246  */
2247 function reset_login_count() {
2248     global $SESSION;
2249
2250     $SESSION->logincount = 0;
2251 }
2252
2253 function sync_metacourses() {
2254
2255     global $CFG;
2256
2257     if (!$courses = get_records('course', 'metacourse', 1)) {
2258         return;
2259     }
2260
2261     foreach ($courses as $course) {
2262         sync_metacourse($course);
2263     }
2264 }
2265
2266 /**
2267  * Goes through all enrolment records for the courses inside the metacourse and sync with them.
2268  *
2269  * @param mixed $course the metacourse to synch. Either the course object itself, or the courseid.
2270  */
2271 function sync_metacourse($course) {
2272     global $CFG;
2273
2274     // Check the course is valid.
2275     if (!is_object($course)) {
2276         if (!$course = get_record('course', 'id', $course)) {
2277             return false; // invalid course id
2278         }
2279     }
2280
2281     // Check that we actually have a metacourse.
2282     if (empty($course->metacourse)) {
2283         return false;
2284     }
2285
2286     // Get a list of roles that should not be synced.
2287     if (!empty($CFG->nonmetacoursesyncroleids)) {
2288         $roleexclusions = 'ra.roleid NOT IN (' . $CFG->nonmetacoursesyncroleids . ') AND';
2289     } else {
2290         $roleexclusions = '';
2291     }
2292
2293     // Get the context of the metacourse.
2294     $context = get_context_instance(CONTEXT_COURSE, $course->id); // SITEID can not be a metacourse
2295
2296     // We do not ever want to unassign the list of metacourse manager, so get a list of them.
2297     if ($users = get_users_by_capability($context, 'moodle/course:managemetacourse')) {
2298         $managers = array_keys($users);
2299     } else {
2300         $managers = array();
2301     }
2302
2303     // Get assignments of a user to a role that exist in a child course, but
2304     // not in the meta coure. That is, get a list of the assignments that need to be made.
2305     if (!$assignments = get_records_sql("
2306             SELECT
2307                 ra.id, ra.roleid, ra.userid
2308             FROM
2309                 {$CFG->prefix}role_assignments ra,
2310                 {$CFG->prefix}context con,
2311                 {$CFG->prefix}course_meta cm
2312             WHERE
2313                 ra.contextid = con.id AND
2314                 con.contextlevel = " . CONTEXT_COURSE . " AND
2315                 con.instanceid = cm.child_course AND
2316                 cm.parent_course = {$course->id} AND
2317                 $roleexclusions
2318                 NOT EXISTS (
2319                     SELECT 1 FROM
2320                         {$CFG->prefix}role_assignments ra2
2321                     WHERE
2322                         ra2.userid = ra.userid AND
2323                         ra2.roleid = ra.roleid AND
2324                         ra2.contextid = {$context->id}
2325                 )
2326     ")) {
2327         $assignments = array();
2328     }
2329
2330     // Get assignments of a user to a role that exist in the meta course, but
2331     // not in any child courses. That is, get a list of the unassignments that need to be made.
2332     if (!$unassignments = get_records_sql("
2333             SELECT
2334                 ra.id, ra.roleid, ra.userid
2335             FROM
2336                 {$CFG->prefix}role_assignments ra
2337             WHERE
2338                 ra.contextid = {$context->id} AND
2339                 $roleexclusions
2340                 NOT EXISTS (
2341                     SELECT 1 FROM
2342                         {$CFG->prefix}role_assignments ra2,
2343                         {$CFG->prefix}context con2,
2344                         {$CFG->prefix}course_meta cm
2345                     WHERE
2346                         ra2.userid = ra.userid AND
2347                         ra2.roleid = ra.roleid AND
2348                         ra2.contextid = con2.id AND
2349                         con2.contextlevel = " . CONTEXT_COURSE . " AND
2350                         con2.instanceid = cm.child_course AND
2351                         cm.parent_course = {$course->id}
2352                 )
2353     ")) {
2354         $unassignments = array();
2355     }
2356
2357     $success = true;
2358
2359     // Make the unassignments, if they are not managers.
2360     foreach ($unassignments as $unassignment) {
2361         if (!in_array($unassignment->userid, $managers)) {
2362             $success = role_unassign($unassignment->roleid, $unassignment->userid, 0, $context->id) && $success;
2363         }
2364     }
2365
2366     // Make the assignments.
2367     foreach ($assignments as $assignment) {
2368         $success = role_assign($assignment->roleid, $assignment->userid, 0, $context->id) && $success;
2369     }
2370
2371     return $success;
2372
2373 // TODO: finish timeend and timestart
2374 // maybe we could rely on cron job to do the cleaning from time to time
2375 }
2376
2377 /**
2378  * Adds a record to the metacourse table and calls sync_metacoures
2379  */
2380 function add_to_metacourse ($metacourseid, $courseid) {
2381
2382     if (!$metacourse = get_record("course","id",$metacourseid)) {
2383         return false;
2384     }
2385
2386     if (!$course = get_record("course","id",$courseid)) {
2387         return false;
2388     }
2389
2390     if (!$record = get_record("course_meta","parent_course",$metacourseid,"child_course",$courseid)) {
2391         $rec = new object();
2392         $rec->parent_course = $metacourseid;
2393         $rec->child_course = $courseid;
2394         if (!insert_record('course_meta',$rec)) {
2395             return false;
2396         }
2397         return sync_metacourse($metacourseid);
2398     }
2399     return true;
2400
2401 }
2402
2403 /**
2404  * Removes the record from the metacourse table and calls sync_metacourse
2405  */
2406 function remove_from_metacourse($metacourseid, $courseid) {
2407
2408     if (delete_records('course_meta','parent_course',$metacourseid,'child_course',$courseid)) {
2409         return sync_metacourse($metacourseid);
2410     }
2411     return false;
2412 }
2413
2414
2415 /**
2416  * Determines if a user is currently logged in
2417  *
2418  * @uses $USER
2419  * @return bool
2420  */
2421 function isloggedin() {
2422     global $USER;
2423
2424     return (!empty($USER->id));
2425 }
2426
2427 /**
2428  * Determines if a user is logged in as real guest user with username 'guest'.
2429  * This function is similar to original isguest() in 1.6 and earlier.
2430  * Current isguest() is deprecated - do not use it anymore.
2431  *
2432  * @param $user mixed user object or id, $USER if not specified
2433  * @return bool true if user is the real guest user, false if not logged in or other user
2434  */
2435 function isguestuser($user=NULL) {
2436     global $USER;
2437     if ($user === NULL) {
2438         $user = $USER;
2439     } else if (is_numeric($user)) {
2440         $user = get_record('user', 'id', $user, '', '', '', '', 'id, username');
2441     }
2442
2443     if (empty($user->id)) {
2444         return false; // not logged in, can not be guest
2445     }
2446
2447     return ($user->username == 'guest');
2448 }
2449
2450 /**
2451  * Determines if the currently logged in user is in editing mode.
2452  * Note: originally this function had $userid parameter - it was not usable anyway
2453  *
2454  * @uses $USER, $PAGE
2455  * @return bool
2456  */
2457 function isediting() {
2458     global $USER, $PAGE;
2459
2460     if (empty($USER->editing)) {
2461         return false;
2462     } elseif (is_object($PAGE) && method_exists($PAGE,'user_allowed_editing')) {
2463         return $PAGE->user_allowed_editing();
2464     }
2465     return true;//false;
2466 }
2467
2468 /**
2469  * Determines if the logged in user is currently moving an activity
2470  *
2471  * @uses $USER
2472  * @param int $courseid The id of the course being tested
2473  * @return bool
2474  */
2475 function ismoving($courseid) {
2476     global $USER;
2477
2478     if (!empty($USER->activitycopy)) {
2479         return ($USER->activitycopycourse == $courseid);
2480     }
2481     return false;
2482 }
2483
2484 /**
2485  * Given an object containing firstname and lastname
2486  * values, this function returns a string with the
2487  * full name of the person.
2488  * The result may depend on system settings
2489  * or language.  'override' will force both names
2490  * to be used even if system settings specify one.
2491  *
2492  * @uses $CFG
2493  * @uses $SESSION
2494  * @param object $user A {@link $USER} object to get full name of
2495  * @param bool $override If true then the name will be first name followed by last name rather than adhering to fullnamedisplay setting.
2496  */
2497 function fullname($user, $override=false) {
2498
2499     global $CFG, $SESSION;
2500
2501     if (!isset($user->firstname) and !isset($user->lastname)) {
2502         return '';
2503     }
2504
2505     if (!$override) {
2506         if (!empty($CFG->forcefirstname)) {
2507             $user->firstname = $CFG->forcefirstname;
2508         }
2509         if (!empty($CFG->forcelastname)) {
2510             $user->lastname = $CFG->forcelastname;
2511         }
2512     }
2513
2514     if (!empty($SESSION->fullnamedisplay)) {
2515         $CFG->fullnamedisplay = $SESSION->fullnamedisplay;
2516     }
2517
2518     if ($CFG->fullnamedisplay == 'firstname lastname') {
2519         return $user->firstname .' '. $user->lastname;
2520
2521     } else if ($CFG->fullnamedisplay == 'lastname firstname') {
2522         return $user->lastname .' '. $user->firstname;
2523
2524     } else if ($CFG->fullnamedisplay == 'firstname') {
2525         if ($override) {
2526             return get_string('fullnamedisplay', '', $user);
2527         } else {
2528             return $user->firstname;
2529         }
2530     }
2531
2532     return get_string('fullnamedisplay', '', $user);
2533 }
2534
2535 /**
2536  * Sets a moodle cookie with an encrypted string
2537  *
2538  * @uses $CFG
2539  * @uses DAYSECS
2540  * @uses HOURSECS
2541  * @param string $thing The string to encrypt and place in a cookie
2542  */
2543 function set_moodle_cookie($thing) {
2544     global $CFG;
2545
2546     if ($thing == 'guest') {  // Ignore guest account
2547         return;
2548     }
2549
2550     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2551
2552     $days = 60;
2553     $seconds = DAYSECS*$days;
2554
2555     setCookie($cookiename, '', time() - HOURSECS, $CFG->sessioncookiepath);
2556     setCookie($cookiename, rc4encrypt($thing), time()+$seconds, $CFG->sessioncookiepath);
2557 }
2558
2559 /**
2560  * Gets a moodle cookie with an encrypted string
2561  *
2562  * @uses $CFG
2563  * @return string
2564  */
2565 function get_moodle_cookie() {
2566     global $CFG;
2567
2568     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2569
2570     if (empty($_COOKIE[$cookiename])) {
2571         return '';
2572     } else {
2573         $thing = rc4decrypt($_COOKIE[$cookiename]);
2574         return ($thing == 'guest') ? '': $thing;  // Ignore guest account
2575     }
2576 }
2577
2578 /**
2579  * Returns whether a given authentication plugin exists.
2580  *
2581  * @uses $CFG
2582  * @param string $auth Form of authentication to check for. Defaults to the
2583  *        global setting in {@link $CFG}.
2584  * @return boolean Whether the plugin is available.
2585  */
2586 function exists_auth_plugin($auth) {
2587     global $CFG;
2588
2589     if (file_exists("{$CFG->dirroot}/auth/$auth/auth.php")) {
2590         return is_readable("{$CFG->dirroot}/auth/$auth/auth.php");
2591     }
2592     return false;
2593 }
2594
2595 /**
2596  * Checks if a given plugin is in the list of enabled authentication plugins.
2597  *
2598  * @param string $auth Authentication plugin.
2599  * @return boolean Whether the plugin is enabled.
2600  */
2601 function is_enabled_auth($auth) {
2602     if (empty($auth)) {
2603         return false;
2604     }
2605
2606     $enabled = get_enabled_auth_plugins();
2607
2608     return in_array($auth, $enabled);
2609 }
2610
2611 /**
2612  * Returns an authentication plugin instance.
2613  *
2614  * @uses $CFG
2615  * @param string $auth name of authentication plugin
2616  * @return object An instance of the required authentication plugin.
2617  */
2618 function get_auth_plugin($auth) {
2619     global $CFG;
2620
2621     // check the plugin exists first
2622     if (! exists_auth_plugin($auth)) {
2623         error("Authentication plugin '$auth' not found.");
2624     }
2625
2626     // return auth plugin instance
2627     require_once "{$CFG->dirroot}/auth/$auth/auth.php";
2628     $class = "auth_plugin_$auth";
2629     return new $class;
2630 }
2631
2632 /**
2633  * Returns array of active auth plugins.
2634  *
2635  * @param bool $fix fix $CFG->auth if needed
2636  * @return array
2637  */
2638 function get_enabled_auth_plugins($fix=false) {
2639     global $CFG;
2640
2641     $default = array('manual', 'nologin');
2642
2643     if (empty($CFG->auth)) {
2644         $auths = array();
2645     } else {
2646         $auths = explode(',', $CFG->auth);
2647     }
2648
2649     if ($fix) {
2650         $auths = array_unique($auths);
2651         foreach($auths as $k=>$authname) {
2652             if (!exists_auth_plugin($authname) or in_array($authname, $default)) {
2653                 unset($auths[$k]);
2654             }
2655         }
2656         $newconfig = implode(',', $auths);
2657         if (!isset($CFG->auth) or $newconfig != $CFG->auth) {
2658             set_config('auth', $newconfig);
2659         }
2660     }
2661
2662     return (array_merge($default, $auths));
2663 }
2664
2665 /**
2666  * Returns true if an internal authentication method is being used.
2667  * if method not specified then, global default is assumed
2668  *
2669  * @uses $CFG
2670  * @param string $auth Form of authentication required
2671  * @return bool
2672  */
2673 function is_internal_auth($auth) {
2674     $authplugin = get_auth_plugin($auth); // throws error if bad $auth
2675     return $authplugin->is_internal();
2676 }
2677
2678 /**
2679  * Returns an array of user fields
2680  *
2681  * @uses $CFG
2682  * @uses $db
2683  * @return array User field/column names
2684  */
2685 function get_user_fieldnames() {
2686
2687     global $CFG, $db;
2688
2689     $fieldarray = $db->MetaColumnNames($CFG->prefix.'user');
2690     unset($fieldarray['ID']);
2691
2692     return $fieldarray;
2693 }
2694
2695 /**
2696  * Creates the default "guest" user. Used both from
2697  * admin/index.php and login/index.php
2698  * @return mixed user object created or boolean false if the creation has failed
2699  */
2700 function create_guest_record() {
2701
2702     global $CFG;
2703
2704     $guest = new stdClass();
2705     $guest->auth        = 'manual';
2706     $guest->username    = 'guest';
2707     $guest->password    = hash_internal_user_password('guest');
2708     $guest->firstname   = addslashes(get_string('guestuser'));
2709     $guest->lastname    = ' ';
2710     $guest->email       = 'root@localhost';
2711     $guest->description = addslashes(get_string('guestuserinfo'));
2712     $guest->mnethostid  = $CFG->mnet_localhost_id;
2713     $guest->confirmed   = 1;
2714     $guest->lang        = $CFG->lang;
2715     $guest->timemodified= time();
2716
2717     if (! $guest->id = insert_record("user", $guest)) {
2718         return false;
2719     }
2720
2721     return $guest;
2722 }
2723
2724 /**
2725  * Creates a bare-bones user record
2726  *
2727  * @uses $CFG
2728  * @param string $username New user's username to add to record
2729  * @param string $password New user's password to add to record
2730  * @param string $auth Form of authentication required
2731  * @return object A {@link $USER} object
2732  * @todo Outline auth types and provide code example
2733  */
2734 function create_user_record($username, $password, $auth='manual') {
2735     global $CFG;
2736
2737     //just in case check text case
2738     $username = trim(moodle_strtolower($username));
2739
2740     $authplugin = get_auth_plugin($auth);
2741
2742     if ($newinfo = $authplugin->get_userinfo($username)) {
2743         $newinfo = truncate_userinfo($newinfo);
2744         foreach ($newinfo as $key => $value){
2745             $newuser->$key = addslashes($value);
2746         }
2747     }
2748
2749     if (!empty($newuser->email)) {
2750         if (email_is_not_allowed($newuser->email)) {
2751             unset($newuser->email);
2752         }
2753     }
2754
2755     $newuser->auth = $auth;
2756     $newuser->username = $username;
2757
2758     // fix for MDL-8480
2759     // user CFG lang for user if $newuser->lang is empty
2760     // or $user->lang is not an installed language
2761     $sitelangs = array_keys(get_list_of_languages());
2762     if (empty($newuser->lang) || !in_array($newuser->lang, $sitelangs)) {
2763         $newuser -> lang = $CFG->lang;
2764     }
2765     $newuser->confirmed = 1;
2766     $newuser->lastip = getremoteaddr();
2767     $newuser->timemodified = time();
2768     $newuser->mnethostid = $CFG->mnet_localhost_id;
2769
2770     if (insert_record('user', $newuser)) {
2771         $user = get_complete_user_data('username', $newuser->username);
2772         if(!empty($CFG->{'auth_'.$newuser->auth.'_forcechangepassword'})){
2773             set_user_preference('auth_forcepasswordchange', 1, $user->id);
2774         }
2775         update_internal_user_password($user, $password);
2776         return $user;
2777     }
2778     return false;
2779 }
2780
2781 /**
2782  * Will update a local user record from an external source
2783  *
2784  * @uses $CFG
2785  * @param string $username New user's username to add to record
2786  * @return user A {@link $USER} object
2787  */
2788 function update_user_record($username, $authplugin) {
2789     $username = trim(moodle_strtolower($username)); /// just in case check text case
2790
2791     $oldinfo = get_record('user', 'username', $username, '','','','', 'username, auth');
2792     $userauth = get_auth_plugin($oldinfo->auth);
2793
2794     if ($newinfo = $userauth->get_userinfo($username)) {
2795         $newinfo = truncate_userinfo($newinfo);
2796         foreach ($newinfo as $key => $value){
2797             $confkey = 'field_updatelocal_' . $key;
2798             if (!empty($userauth->config->$confkey) and $userauth->config->$confkey === 'onlogin') {
2799                 $value = addslashes(stripslashes($value));   // Just in case
2800                 set_field('user', $key, $value, 'username', $username)
2801                     or error_log("Error updating $key for $username");
2802             }
2803         }
2804     }
2805
2806     return get_complete_user_data('username', $username);
2807 }
2808
2809 function truncate_userinfo($info) {
2810 /// will truncate userinfo as it comes from auth_get_userinfo (from external auth)
2811 /// which may have large fields
2812
2813     // define the limits
2814     $limit = array(
2815                     'username'    => 100,
2816                     'idnumber'    =>  64,
2817                     'firstname'   => 100,
2818                     'lastname'    => 100,
2819                     'email'       => 100,
2820                     'icq'         =>  15,
2821                     'phone1'      =>  20,
2822                     'phone2'      =>  20,
2823                     'institution' =>  40,
2824                     'department'  =>  30,
2825                     'address'     =>  70,
2826                     'city'        =>  20,
2827                     'country'     =>   2,
2828                     'url'         => 255,
2829                     );
2830
2831     // apply where needed
2832     foreach (array_keys($info) as $key) {
2833         if (!empty($limit[$key])) {
2834             $info[$key] = trim(substr($info[$key],0, $limit[$key]));
2835         }
2836     }
2837
2838     return $info;
2839 }
2840
2841 /**
2842  * Marks user deleted in internal user database and notifies the auth plugin.
2843  * Also unenrols user from all roles and does other cleanup.
2844  * @param object $user       Userobject before delete    (without system magic quotes)
2845  * @return boolean success
2846  */
2847 function delete_user($user) {
2848     global $CFG;
2849     require_once($CFG->libdir.'/grouplib.php');
2850     require_once($CFG->libdir.'/gradelib.php');
2851
2852     begin_sql();
2853
2854     // delete all grades - backup is kept in grade_grades_history table
2855     if ($grades = grade_grade::fetch_all(array('userid'=>$user->id))) {
2856         foreach ($grades as $grade) {
2857             $grade->delete('userdelete');
2858         }
2859     }
2860
2861     // remove from all groups
2862     delete_records('groups_members', 'userid', $user->id);
2863
2864     // unenrol from all roles in all contexts
2865     role_unassign(0, $user->id); // this might be slow but it is really needed - modules might do some extra cleanup!
2866
2867     // now do a final accesslib cleanup - removes all role assingments in user context and context itself
2868     delete_context(CONTEXT_USER, $user->id);
2869
2870     // mark internal user record as "deleted"
2871     $updateuser = new object();
2872     $updateuser->id           = $user->id;
2873     $updateuser->deleted      = 1;
2874     $updateuser->username     = addslashes("$user->email.".time());  // Remember it just in case
2875     $updateuser->email        = '';               // Clear this field to free it up
2876     $updateuser->idnumber     = '';               // Clear this field to free it up
2877     $updateuser->timemodified = time();
2878
2879     if (update_record('user', $updateuser)) {
2880         commit_sql();
2881         // notify auth plugin - do not block the delete even when plugin fails
2882         $authplugin = get_auth_plugin($user->auth);
2883         $authplugin->user_delete($user);
2884         return true;
2885
2886     } else {
2887         rollback_sql();
2888         return false;
2889     }
2890 }
2891
2892 /**
2893  * Retrieve the guest user object
2894  *
2895  * @uses $CFG
2896  * @return user A {@link $USER} object
2897  */
2898 function guest_user() {
2899     global $CFG;
2900
2901     if ($newuser = get_record('user', 'username', 'guest', 'mnethostid',  $CFG->mnet_localhost_id)) {
2902         $newuser->confirmed = 1;
2903         $newuser->lang = $CFG->lang;
2904         $newuser->lastip = getremoteaddr();
2905     }
2906
2907     return $newuser;
2908 }
2909
2910 /**
2911  * Given a username and password, this function looks them
2912  * up using the currently selected authentication mechanism,
2913  * and if the authentication is successful, it returns a
2914  * valid $user object from the 'user' table.
2915  *
2916  * Uses auth_ functions from the currently active auth module
2917  *
2918  * @uses $CFG
2919  * @param string $username  User's username (with system magic quotes)
2920  * @param string $password  User's password (with system magic quotes)
2921  * @return user|flase A {@link $USER} object or false if error
2922  */
2923 function authenticate_user_login($username, $password) {
2924
2925     global $CFG;
2926
2927     $authsenabled = get_enabled_auth_plugins();
2928
2929     if ($user = get_complete_user_data('username', $username)) {
2930         $auth = empty($user->auth) ? 'manual' : $user->auth;  // use manual if auth not set
2931         if ($auth=='nologin' or !is_enabled_auth($auth)) {
2932             add_to_log(0, 'login', 'error', 'index.php', $username);
2933             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Disabled Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2934             return false;
2935         }
2936         if (!empty($user->deleted)) {
2937             add_to_log(0, 'login', 'error', 'index.php', $username);
2938             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Deleted Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2939             return false;
2940         }
2941         $auths = array($auth);
2942
2943     } else {
2944         $auths = $authsenabled;
2945         $user = new object();
2946         $user->id = 0;     // User does not exist
2947     }
2948
2949     foreach ($auths as $auth) {
2950         $authplugin = get_auth_plugin($auth);
2951
2952         // on auth fail fall through to the next plugin
2953         if (!$authplugin->user_login($username, $password)) {
2954             continue;
2955         }
2956
2957         // successful authentication
2958         if ($user->id) {                          // User already exists in database
2959             if (empty($user->auth)) {             // For some reason auth isn't set yet
2960                 set_field('user', 'auth', $auth, 'username', $username);
2961                 $user->auth = $auth;
2962             }
2963
2964             update_internal_user_password($user, $password); // just in case salt or encoding were changed (magic quotes too one day)
2965
2966             if (!$authplugin->is_internal()) {            // update user record from external DB
2967                 $user = update_user_record($username, get_auth_plugin($user->auth));
2968             }
2969         } else {
2970             // if user not found, create him
2971             $user = create_user_record($username, $password, $auth);
2972         }
2973
2974         $authplugin->sync_roles($user);
2975
2976         foreach ($authsenabled as $hau) {
2977             $hauth = get_auth_plugin($hau);
2978             $hauth->user_authenticated_hook($user, $username, $password);
2979         }
2980
2981     /// Log in to a second system if necessary
2982     /// NOTICE: /sso/ will be moved to auth and deprecated soon; use user_authenticated_hook() instead
2983         if (!empty($CFG->sso)) {
2984             include_once($CFG->dirroot .'/sso/'. $CFG->sso .'/lib.php');
2985             if (function_exists('sso_user_login')) {
2986                 if (!sso_user_login($username, $password)) {   // Perform the signon process
2987                     notify('Second sign-on failed');
2988                 }
2989             }
2990         }
2991
2992         return $user;
2993
2994     }
2995
2996     // failed if all the plugins have failed
2997     add_to_log(0, 'login', 'error', 'index.php', $username);
2998     error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Failed Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2999     return false;
3000 }
3001
3002 /**
3003  * Compare password against hash stored in internal user table.
3004  * If necessary it also updates the stored hash to new format.
3005  *
3006  * @param object user
3007  * @param string plain text password
3008  * @return bool is password valid?
3009  */
3010 function validate_internal_user_password(&$user, $password) {
3011     global $CFG;
3012
3013     if (!isset($CFG->passwordsaltmain)) {
3014         $CFG->passwordsaltmain = '';
3015     }
3016
3017     $validated = false;
3018
3019     // get password original encoding in case it was not updated to unicode yet
3020     $textlib = textlib_get_instance();
3021     $convpassword = $textlib->convert($password, 'utf-8', get_string('oldcharset'));
3022
3023     if ($user->password == md5($password.$CFG->passwordsaltmain) or $user->password == md5($password)
3024         or $user->password == md5($convpassword.$CFG->passwordsaltmain) or $user->password == md5($convpassword)) {
3025         $validated = true;
3026     } else {
3027         for ($i=1; $i<=20; $i++) { //20 alternative salts should be enough, right?
3028             $alt = 'passwordsaltalt'.$i;
3029             if (!empty($CFG->$alt)) {
3030                 if ($user->password == md5($password.$CFG->$alt) or $user->password == md5($convpassword.$CFG->$alt)) {
3031                     $validated = true;
3032                     break;
3033                 }
3034             }
3035         }
3036     }
3037
3038     if ($validated) {
3039         // force update of password hash using latest main password salt and encoding if needed
3040         update_internal_user_password($user, $password);
3041     }
3042
3043     return $validated;
3044 }
3045
3046 /**
3047  * Calculate hashed value from password using current hash mechanism.
3048  *
3049  * @param string password
3050  * @return string password hash
3051  */
3052 function hash_internal_user_password($password) {
3053     global $CFG;
3054
3055     if (isset($CFG->passwordsaltmain)) {
3056         return md5($password.$CFG->passwordsaltmain);
3057     } else {
3058         return md5($password);
3059     }
3060 }
3061
3062 /**
3063  * Update pssword hash in user object.
3064  *
3065  * @param object user
3066  * @param string plain text password
3067  * @param bool store changes also in db, default true
3068  * @return true if hash changed
3069  */
3070 function update_internal_user_password(&$user, $password) {
3071     global $CFG;
3072
3073     $authplugin = get_auth_plugin($user->auth);
3074     if (!empty($authplugin->config->preventpassindb)) {
3075         $hashedpassword = 'not cached';
3076     } else {
3077         $hashedpassword = hash_internal_user_password($password);
3078     }
3079
3080     return set_field('user', 'password',  $hashedpassword, 'id', $user->id);
3081 }
3082
3083 /**
3084  * Get a complete user record, which includes all the info
3085  * in the user record
3086  * Intended for setting as $USER session variable
3087  *
3088  * @uses $CFG
3089  * @uses SITEID
3090  * @param string $field The user field to be checked for a given value.
3091  * @param string $value The value to match for $field.
3092  * @return user A {@link $USER} object.
3093  */
3094 function get_complete_user_data($field, $value, $mnethostid=null) {
3095
3096     global $CFG;
3097
3098     if (!$field || !$value) {
3099         return false;
3100     }
3101
3102 /// Build the WHERE clause for an SQL query
3103
3104     $constraints = $field .' = \''. $value .'\' AND deleted <> \'1\'';
3105
3106     if (is_null($mnethostid)) {
3107         // if null, we restrict to local users
3108         // ** testing for local user can be done with
3109         //    mnethostid = $CFG->mnet_localhost_id
3110         //    or with
3111         //    auth != 'mnet'
3112         //    but the first one is FAST with our indexes
3113         $mnethostid = $CFG->mnet_localhost_id;
3114     }
3115     $mnethostid = (int)$mnethostid;
3116     $constraints .= ' AND mnethostid = \''.$mnethostid.'\'';
3117
3118 /// Get all the basic user data
3119
3120     if (! $user = get_record_select('user', $constraints)) {
3121         return false;
3122     }
3123
3124 /// Get various settings and preferences
3125
3126     if ($displays = get_records('course_display', 'userid', $user->id)) {
3127         foreach ($displays as $display) {
3128             $user->display[$display->course] = $display->display;
3129         }
3130     }
3131
3132     $user->preference = get_user_preferences(null, null, $user->id);
3133
3134     if ($lastaccesses = get_records('user_lastaccess', 'userid', $user->id)) {
3135         foreach ($lastaccesses as $lastaccess) {
3136             $user->lastcourseaccess[$lastaccess->courseid] = $lastaccess->timeaccess;
3137         }
3138     }
3139
3140     $sql = "SELECT g.id, g.courseid
3141               FROM {$CFG->prefix}groups g, {$CFG->prefix}groups_members gm
3142              WHERE gm.groupid=g.id AND gm.userid={$user->id}";
3143
3144     // this is a special hack to speedup calendar display
3145     $user->groupmember = array();
3146     if ($groups = get_records_sql($sql)) {
3147         foreach ($groups as $group) {
3148             if (!array_key_exists($group->courseid, $user->groupmember)) {
3149                 $user->groupmember[$group->courseid] = array();
3150             }
3151             $user->groupmember[$group->courseid][$group->id] = $group->id;
3152         }
3153     }
3154
3155 /// Add the custom profile fields to the user record
3156     include_once($CFG->dirroot.'/user/profile/lib.php');
3157     $customfields = (array)profile_user_record($user->id);
3158     foreach ($customfields as $cname=>$cvalue) {
3159         if (!isset($user->$cname)) { // Don't overwrite any standard fields
3160             $user->$cname = $cvalue;
3161         }
3162     }
3163
3164 /// Rewrite some variables if necessary
3165     if (!empty($user->description)) {
3166         $user->description = true;   // No need to cart all of it around
3167     }
3168     if ($user->username == 'guest') {
3169         $user->lang       = $CFG->lang;               // Guest language always same as site
3170         $user->firstname  = get_string('guestuser');  // Name always in current language
3171         $user->lastname   = ' ';
3172     }
3173
3174     $user->sesskey  = random_string(10);
3175     $user->sessionIP = md5(getremoteaddr());   // Store the current IP in the session
3176
3177     return $user;
3178 }
3179
3180 /**
3181  * @uses $CFG
3182  * @param string $password the password to be checked agains the password policy
3183  * @param string $errmsg the error message to display when the password doesn't comply with the policy.
3184  * @return bool true if the password is valid according to the policy. false otherwise.
3185  */
3186 function check_password_policy($password, &$errmsg) {
3187     global $CFG;
3188
3189     if (empty($CFG->passwordpolicy)) {
3190         return true;
3191     }
3192
3193     $textlib = textlib_get_instance();
3194     $errmsg = '';
3195     if ($textlib->strlen($password) < $CFG->minpasswordlength) {
3196         $errmsg = get_string('errorminpasswordlength', 'auth', $CFG->minpasswordlength);
3197
3198     } else if (preg_match_all('/[[:digit:]]/u', $password, $matches) < $CFG->minpassworddigits) {
3199         $errmsg = get_string('errorminpassworddigits', 'auth', $CFG->minpassworddigits);
3200
3201     } else if (preg_match_all('/[[:lower:]]/u', $password, $matches) < $CFG->minpasswordlower) {
3202         $errmsg = get_string('errorminpasswordlower', 'auth', $CFG->minpasswordlower);
3203
3204     } else if (preg_match_all('/[[:upper:]]/u', $password, $matches) < $CFG->minpasswordupper) {
3205         $errmsg = get_string('errorminpasswordupper', 'auth', $CFG->minpasswordupper);
3206
3207     } else if (preg_match_all('/[^[:upper:][:lower:][:digit:]]/u', $password, $matches) < $CFG->minpasswordnonalphanum) {
3208         $errmsg = get_string('errorminpasswordnonalphanum', 'auth', $CFG->minpasswordnonalphanum);
3209
3210     } else if ($password == 'admin' or $password == 'password') {
3211         $errmsg = get_string('unsafepassword');
3212     }
3213
3214     if ($errmsg == '') {
3215         return true;
3216     } else {
3217         return false;
3218     }
3219 }
3220
3221
3222 /**
3223  * When logging in, this function is run to set certain preferences
3224  * for the current SESSION
3225  */
3226 function set_login_session_preferences() {
3227     global $SESSION, $CFG;
3228
3229     $SESSION->justloggedin = true;
3230
3231     unset($SESSION->lang);
3232
3233     // Restore the calendar filters, if saved
3234     if (intval(get_user_preferences('calendar_persistflt', 0))) {
3235         include_once($CFG->dirroot.'/calendar/lib.php');
3236         calendar_set_filters_status(get_user_preferences('calendav_savedflt', 0xff));
3237     }
3238 }
3239
3240
3241 /**
3242  * Delete a course, including all related data from the database,
3243  * and any associated files from the moodledata folder.
3244  *
3245  * @param int $courseid The id of the course to delete.
3246  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3247  * @return bool true if all the removals succeeded. false if there were any failures. If this
3248  *             method returns false, some of the removals will probably have succeeded, and others
3249  *             failed, but you have no way of knowing which.
3250  */
3251 function delete_course($courseid, $showfeedback = true) {
3252     global $CFG;
3253     require_once($CFG->libdir.'/gradelib.php');
3254     $result = true;
3255
3256     // frontpage course can not be deleted!!
3257     if ($courseid == SITEID) {
3258         return false;
3259     }
3260
3261     $context = get_context_instance(CONTEXT_COURSE, $courseid);
3262
3263     if (!remove_course_contents($courseid, $showfeedback)) {
3264         if ($showfeedback) {
3265             notify("An error occurred while deleting some of the course contents.");
3266         }
3267         $result = false;
3268     }
3269
3270     remove_course_grades($courseid, $showfeedback);
3271     remove_grade_letters($context, $showfeedback);
3272
3273     if (!delete_records("course", "id", $courseid)) {
3274         if ($showfeedback) {
3275             notify("An error occurred while deleting the main course record.");
3276         }
3277         $result = false;
3278     }
3279
3280 /// Delete all roles and overiddes in the course context
3281     if (!delete_context(CONTEXT_COURSE, $courseid)) {
3282         if ($showfeedback) {
3283             notify("An error occurred while deleting the main course context.");
3284         }
3285         $result = false;
3286     }
3287
3288     if (!fulldelete($CFG->dataroot.'/'.$courseid)) {
3289         if ($showfeedback) {
3290             notify("An error occurred while deleting the course files.");
3291         }
3292         $result = false;
3293     }
3294
3295     return $result;
3296 }
3297
3298 /**
3299  * Clear a course out completely, deleting all content
3300  * but don't delete the course itself
3301  *
3302  * @uses $CFG
3303  * @param int $courseid The id of the course that is being deleted
3304  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3305  * @return bool true if all the removals succeeded. false if there were any failures. If this
3306  *             method returns false, some of the removals will probably have succeeded, and others
3307  *             failed, but you have no way of knowing which.
3308  */
3309 function remove_course_contents($courseid, $showfeedback=true) {
3310
3311     global $CFG;
3312     include_once($CFG->libdir.'/questionlib.php');
3313
3314     $result = true;
3315
3316     if (! $course = get_record('course', 'id', $courseid)) {
3317         error('Course ID was incorrect (can\'t find it)');
3318     }
3319
3320     $strdeleted = get_string('deleted');
3321
3322 /// First delete every instance of every module
3323
3324     if ($allmods = get_records('modules') ) {
3325         foreach ($allmods as $mod) {
3326             $modname = $mod->name;
3327             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3328             $moddelete = $modname .'_delete_instance';       // Delete everything connected to an instance
3329             $moddeletecourse = $modname .'_delete_course';   // Delete other stray stuff (uncommon)
3330             $count=0;
3331             if (file_exists($modfile)) {
3332                 include_once($modfile);
3333                 if (function_exists($moddelete)) {
3334                     if ($instances = get_records($modname, 'course', $course->id)) {
3335                         foreach ($instances as $instance) {
3336                             if ($cm = get_coursemodule_from_instance($modname, $instance->id, $course->id)) {
3337                                 /// Delete activity context questions and question categories
3338                                 question_delete_activity($cm,  $showfeedback);
3339                             }
3340                             if ($moddelete($instance->id)) {
3341                                 $count++;
3342
3343                             } else {
3344                                 notify('Could not delete '. $modname .' instance '. $instance->id .' ('. format_string($instance->name) .')');
3345                                 $result = false;
3346                             }
3347                             if ($cm) {
3348                                 // delete cm and its context in correct order
3349                                 delete_records('course_modules', 'id', $cm->id);
3350                                 delete_context(CONTEXT_MODULE, $cm->id);
3351                             }
3352                         }
3353                     }
3354                 } else {
3355                     notify('Function '. $moddelete() .'doesn\'t exist!');
3356                     $result = false;
3357                 }
3358
3359                 if (function_exists($moddeletecourse)) {
3360                     $moddeletecourse($course, $showfeedback);
3361                 }
3362             }
3363             if ($showfeedback) {
3364                 notify($strdeleted .' '. $count .' x '. $modname);
3365             }
3366         }
3367     } else {
3368         error('No modules are installed!');
3369     }
3370
3371 /// Give local code a chance to delete its references to this course.
3372     require_once('locallib.php');
3373     notify_local_delete_course($courseid, $showfeedback);
3374
3375 /// Delete course blocks
3376
3377     if ($blocks = get_records_sql("SELECT *
3378                                    FROM {$CFG->prefix}block_instance
3379                                    WHERE pagetype = '".PAGE_COURSE_VIEW."'
3380                                    AND pageid = $course->id")) {
3381         if (delete_records('block_instance', 'pagetype', PAGE_COURSE_VIEW, 'pageid', $course->id)) {
3382             if ($showfeedback) {
3383                 notify($strdeleted .' block_instance');
3384             }
3385
3386             require_once($CFG->libdir.'/blocklib.php');
3387             foreach ($blocks as $block) {  /// Delete any associated contexts for this block
3388
3389                 delete_context(CONTEXT_BLOCK, $block->id);
3390
3391                 // fix for MDL-7164
3392                 // Get the block object and call instance_delete()
3393                 if (!$record = blocks_get_record($block->blockid)) {
3394                     $result = false;
3395                     continue;
3396                 }
3397                 if (!$obj = block_instance($record->name, $block)) {
3398                     $result = false;
3399                     continue;
3400                 }
3401                 // Return value ignored, in core mods this does not do anything, but just in case
3402                 // third party blocks might have stuff to clean up
3403                 // we execute this anyway
3404                 $obj->instance_delete();
3405
3406             }
3407         } else {
3408             $result = false;
3409         }
3410     }
3411
3412 /// Delete any groups, removing members and grouping/course links first.
3413     require_once($CFG->dirroot.'/group/lib.php');
3414     groups_delete_groupings($courseid, true);
3415     groups_delete_groups($courseid, true);
3416
3417 /// Delete all related records in other tables that may have a courseid
3418 /// This array stores the tables that need to be cleared, as
3419 /// table_name => column_name that contains the course id.
3420
3421     $tablestoclear = array(
3422         'event' => 'courseid', // Delete events
3423         'log' => 'course', // Delete logs
3424         'course_sections' => 'course', // Delete any course stuff
3425         'course_modules' => 'course',
3426         'backup_courses' => 'courseid', // Delete scheduled backup stuff
3427         'user_lastaccess' => 'courseid',
3428         'backup_log' => 'courseid'
3429     );
3430     foreach ($tablestoclear as $table => $col) {
3431         if (delete_records($table, $col, $course->id)) {
3432             if ($showfeedback) {
3433                 notify($strdeleted . ' ' . $table);
3434             }
3435         } else {
3436             $result = false;
3437         }
3438     }
3439
3440
3441 /// Clean up metacourse stuff
3442
3443     if ($course->metacourse) {
3444         delete_records("course_meta","parent_course",$course->id);
3445         sync_metacourse($course->id); // have to do it here so the enrolments get nuked. sync_metacourses won't find it without the id.
3446         if ($showfeedback) {
3447             notify("$strdeleted course_meta");
3448         }
3449     } else {
3450         if ($parents = get_records("course_meta","child_course",$course->id)) {
3451             foreach ($parents as $parent) {
3452                 remove_from_metacourse($parent->parent_course,$parent->child_course); // this will do the unenrolments as well.
3453             }
3454             if ($showfeedback) {
3455                 notify("$strdeleted course_meta");
3456             }
3457         }
3458     }
3459
3460 /// Delete questions and question categories
3461     question_delete_course($course, $showfeedback);
3462
3463     return $result;
3464 }
3465
3466
3467 /**
3468  * This function will empty a course of USER data as much as
3469 /// possible. It will retain the activities and the structure
3470 /// of the course.
3471  *
3472  * @uses $USER
3473  * @uses $SESSION
3474  * @uses $CFG
3475  * @param object $data an object containing all the boolean settings and courseid
3476  * @param bool $showfeedback  if false then do it all silently
3477  * @return bool
3478  * @todo Finish documenting this function
3479  */
3480 function reset_course_userdata($data, $showfeedback=true) {
3481
3482     global $CFG, $USER, $SESSION;
3483     require_once($CFG->dirroot.'/group/lib.php');
3484
3485     $result = true;
3486
3487     $strdeleted = get_string('deleted');
3488
3489     // Look in every instance of every module for data to delete
3490
3491     if ($allmods = get_records('modules') ) {
3492         foreach ($allmods as $mod) {
3493             $modname = $mod->name;
3494             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3495             $moddeleteuserdata = $modname .'_delete_userdata';   // Function to delete user data
3496             if (file_exists($modfile)) {
3497                 @include_once($modfile);
3498                 if (function_exists($moddeleteuserdata)) {
3499                     $moddeleteuserdata($data, $showfeedback);
3500                 }
3501             }
3502         }
3503     } else {
3504         error('No modules are installed!');
3505     }
3506
3507     // Delete other stuff
3508     $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
3509
3510     if (!empty($data->reset_students) or !empty($data->reset_teachers)) {
3511         $teachers     = array_keys(get_users_by_capability($context, 'moodle/course:update'));
3512         $participants = array_keys(get_users_by_capability($context, 'moodle/course:view'));
3513         $students     = array_diff($participants, $teachers);
3514
3515         if (!empty($data->reset_students)) {
3516             foreach ($students as $studentid) {
3517                 role_unassign(0, $studentid, 0, $context->id);
3518             }
3519             if ($showfeedback) {
3520                 notify($strdeleted .' '.get_string('students'), 'notifysuccess');
3521             }
3522
3523             /// Delete group members (but keep the groups)
3524             $result = groups_delete_group_members($data->courseid, $showfeedback) && $result;
3525         }
3526
3527         if (!empty($data->reset_teachers)) {
3528             foreach ($teachers as $teacherid) {
3529                 role_unassign(0, $teacherid, 0, $context->id);
3530             }
3531             if ($showfeedback) {
3532                 notify($strdeleted .' '.get_string('teachers'), 'notifysuccess');
3533             }
3534         }
3535     }
3536
3537     if (!empty($data->reset_groups)) {
3538             $result = groups_delete_groupings($data->courseid, $showfeedback) && $result;
3539             $result = groups_delete_groups($data->courseid, $showfeedback) && $result;
3540     }
3541
3542     if (!empty($data->reset_events)) {
3543         if (delete_records('event', 'courseid', $data->courseid)) {
3544             if ($showfeedback) {
3545                 notify($strdeleted .' event', 'notifysuccess');
3546             }
3547         } else {
3548             $result = false;
3549         }
3550     }
3551
3552     if (!empty($data->reset_logs)) {
3553         if (delete_records('log', 'course', $data->courseid)) {
3554             if ($showfeedback) {
3555                 notify($strdeleted .' log', 'notifysuccess');
3556             }
3557         } else {
3558             $result = false;
3559         }
3560     }
3561
3562     // deletes all role assignments, and local override,
3563     // these have no courseid in table and needs separate process
3564     delete_records('role_capabilities', 'contextid', $context->id);
3565
3566     // force accessinfo refresh for users visiting this context...
3567     mark_context_dirty($context->path);
3568
3569     return $result;
3570 }
3571
3572 function generate_email_processing_address($modid,$modargs) {
3573     global $CFG;
3574
3575     if (empty($CFG->siteidentifier)) {    // Unique site identification code
3576         set_config('siteidentifier', random_string(32));
3577     }
3578
3579     $header = $CFG->mailprefix . substr(base64_encode(pack('C',$modid)),0,2).$modargs;
3580     return $header . substr(md5($header.$CFG->siteidentifier),0,16).'@'.$CFG->maildomain;
3581 }
3582
3583
3584 function moodle_process_email($modargs,$body) {
3585     // the first char should be an unencoded letter. We'll take this as an action
3586     switch ($modargs{0}) {
3587         case 'B': { // bounce
3588             list(,$userid) = unpack('V',base64_decode(substr($modargs,1,8)));
3589             if ($user = get_record_select("user","id=$userid","id,email")) {
3590                 // check the half md5 of their email
3591                 $md5check = substr(md5($user->email),0,16);
3592                 if ($md5check == substr($modargs, -16)) {
3593                     set_bounce_count($user);
3594                 }
3595                 // else maybe they've already changed it?
3596             }
3597         }
3598         break;
3599         // maybe more later?
3600     }
3601 }
3602
3603 /// CORRESPONDENCE  ////////////////////////////////////////////////
3604
3605 /**
3606  * Send an email to a specified user
3607  *
3608  * @uses $CFG
3609  * @uses $FULLME
3610  * @uses SITEID
3611  * @param user $user  A {@link $USER} object
3612  * @param user $from A {@link $USER} object
3613  * @param string $subject plain text subject line of the email
3614  * @param string $messagetext plain text version of the message
3615  * @param string $messagehtml complete html version of the message (optional)
3616  * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
3617  * @param string $attachname the name of the file (extension indicates MIME)
3618  * @param bool $usetrueaddress determines whether $from email address should
3619  *          be sent out. Will be overruled by user profile setting for maildisplay
3620  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3621  *          was blocked by user and "false" if there was another sort of error.
3622  */
3623 function email_to_user($user, $from, $subject, $messagetext, $messagehtml='', $attachment='', $attachname='', $usetrueaddress=true, $replyto='', $replytoname='') {
3624
3625     global $CFG, $FULLME;
3626
3627     include_once($CFG->libdir .'/phpmailer/class.phpmailer.php');
3628
3629 /// We are going to use textlib services here
3630     $textlib = textlib_get_instance();
3631
3632     if (empty($user)) {
3633         return false;
3634     }
3635
3636     // skip mail to suspended users
3637     if (isset($user->auth) && $user->auth=='nologin') {
3638         return true;
3639     }
3640
3641     if (!empty($user->emailstop)) {
3642         return 'emailstop';
3643     }
3644
3645     if (over_bounce_threshold($user)) {
3646         error_log("User $user->id (".fullname($user).") is over bounce threshold! Not sending.");
3647         return false;
3648     }
3649
3650     $mail = new phpmailer;
3651
3652     $mail->Version = 'Moodle '. $CFG->version;           // mailer version
3653     $mail->PluginDir = $CFG->libdir .'/phpmailer/';      // plugin directory (eg smtp plugin)
3654
3655     $mail->CharSet = 'UTF-8';
3656
3657     if ($CFG->smtphosts == 'qmail') {
3658         $mail->IsQmail();                              // use Qmail system
3659
3660     } else if (empty($CFG->smtphosts)) {
3661         $mail->IsMail();                               // use PHP mail() = sendmail
3662
3663     } else {
3664         $mail->IsSMTP();                               // use SMTP directly
3665         if (!empty($CFG->debugsmtp)) {
3666             echo '<pre>' . "\n";
3667             $mail->SMTPDebug = true;
3668         }
3669         $mail->Host = $CFG->smtphosts;               // specify main and backup servers
3670
3671         if ($CFG->smtpuser) {                          // Use SMTP authentication
3672             $mail->SMTPAuth = true;
3673             $mail->Username = $CFG->smtpuser;
3674             $mail->Password = $CFG->smtppass;
3675         }
3676     }
3677
3678     $supportuser = generate_email_supportuser();
3679
3680
3681     // make up an email address for handling bounces
3682     if (!empty($CFG->handlebounces)) {
3683         $modargs = 'B'.base64_encode(pack('V',$user->id)).substr(md5($user->email),0,16);
3684         $mail->Sender = generate_email_processing_address(0,$modargs);
3685     } else {
3686         $mail->Sender   = $supportuser->email;
3687     }
3688
3689     if (is_string($from)) { // So we can pass whatever we want if there is need
3690         $mail->From     = $CFG->noreplyaddress;
3691         $mail->FromName = $from;
3692     } else if ($usetrueaddress and $from->maildisplay) {
3693         $mail->From     = $from->email;
3694         $mail->FromName = fullname($from);
3695     } else {
3696         $mail->From     = $CFG->noreplyaddress;
3697         $mail->FromName = fullname($from);
3698         if (empty($replyto)) {
3699             $mail->AddReplyTo($CFG->noreplyaddress,get_string('noreplyname'));
3700         }
3701     }
3702
3703     if (!empty($replyto)) {
3704         $mail->AddReplyTo($replyto,$replytoname);
3705     }
3706
3707     $mail->Subject = substr(stripslashes($subject), 0, 900);
3708
3709     $mail->AddAddress($user->email, fullname($user) );
3710
3711     $mail->WordWrap = 79;                               // set word wrap
3712
3713     if (!empty($from->customheaders)) {                 // Add custom headers
3714         if (is_array($from->customheaders)) {
3715             foreach ($from->customheaders as $customheader) {
3716                 $mail->AddCustomHeader($customheader);
3717             }
3718         } else {
3719             $mail->AddCustomHeader($from->customheaders);
3720         }
3721     }
3722
3723     if (!empty($from->priority)) {
3724         $mail->Priority = $from->priority;
3725     }
3726
3727     if ($messagehtml && $user->mailformat == 1) { // Don't ever send HTML to users who don't want it
3728         $mail->IsHTML(true);
3729         $mail->Encoding = 'quoted-printable';           // Encoding to use
3730         $mail->Body    =  $messagehtml;
3731         $mail->AltBody =  "\n$messagetext\n";
3732     } else {
3733         $mail->IsHTML(false);
3734         $mail->Body =  "\n$messagetext\n";
3735     }
3736
3737     if ($attachment && $attachname) {
3738         if (ereg( "\\.\\." ,$attachment )) {    // Security check for ".." in dir path
3739             $mail->AddAddress($supportuser->email, fullname($supportuser, true) );
3740             $mail->AddStringAttachment('Error in attachment.  User attempted to attach a filename with a unsafe name.', 'error.txt', '8bit', 'text/plain');
3741         } else {
3742             require_once($CFG->libdir.'/filelib.php');
3743             $mimetype = mimeinfo('type', $attachname);
3744             $mail->AddAttachment($CFG->dataroot .'/'. $attachment, $attachname, 'base64', $mimetype);
3745         }
3746     }
3747
3748
3749
3750 /// If we are running under Unicode and sitemailcharset or allowusermailcharset are set, convert the email
3751 /// encoding to the specified one
3752     if ((!empty($CFG->sitemailcharset) || !empty($CFG->allowusermailcharset))) {
3753     /// Set it to site mail charset
3754         $charset = $CFG->sitemailcharset;
3755     /// Overwrite it with the user mail charset
3756         if (!empty($CFG->allowusermailcharset)) {
3757             if ($useremailcharset = get_user_preferences('mailcharset', '0', $user->id)) {
3758                 $charset = $useremailcharset;
3759             }
3760         }
3761     /// If it has changed, convert all the necessary strings
3762         $charsets = get_list_of_charsets();
3763         unset($charsets['UTF-8']);
3764         if (in_array($charset, $charsets)) {
3765         /// Save the new mail charset
3766             $mail->CharSet = $charset;
3767         /// And convert some strings
3768             $mail->FromName = $textlib->convert($mail->FromName, 'utf-8', $mail->CharSet); //From Name
3769             foreach ($mail->ReplyTo as $key => $rt) {                                      //ReplyTo Names
3770                 $mail->ReplyTo[$key][1] = $textlib->convert($rt, 'utf-8', $mail->CharSet);
3771             }
3772             $mail->Subject = $textlib->convert($mail->Subject, 'utf-8', $mail->CharSet);   //Subject
3773             foreach ($mail->to as $key => $to) {
3774                 $mail->to[$key][1] = $textlib->convert($to, 'utf-8', $mail->CharSet);      //To Names
3775             }
3776             $mail->Body = $textlib->convert($mail->Body, 'utf-8', $mail->CharSet);         //Body
3777             $mail->AltBody = $textlib->convert($mail->AltBody, 'utf-8', $mail->CharSet);   //Subject
3778         }
3779     }
3780
3781     if ($mail->Send()) {
3782         set_send_count($user);
3783         $mail->IsSMTP();                               // use SMTP directly
3784         if (!empty($CFG->debugsmtp)) {
3785             echo '</pre>';
3786         }
3787         return true;
3788     } else {
3789         mtrace('ERROR: '. $mail->ErrorInfo);
3790         add_to_log(SITEID, 'library', 'mailer', $FULLME, 'ERROR: '. $mail->ErrorInfo);
3791         if (!empty($CFG->debugsmtp)) {
3792             echo '</pre>';
3793         }
3794         return false;
3795     }
3796 }
3797
3798 /**
3799  * Generate a signoff for emails based on support settings
3800  *
3801  */
3802 function generate_email_signoff() {
3803     global $CFG;
3804
3805     $signoff = "\n";
3806     if (!empty($CFG->supportname)) {
3807         $signoff .= $CFG->supportname."\n";
3808     }
3809     if (!empty($CFG->supportemail)) {
3810         $signoff .= $CFG->supportemail."\n";
3811     }
3812     if (!empty($CFG->supportpage)) {
3813         $signoff .= $CFG->supportpage."\n";
3814     }
3815     return $signoff;
3816 }
3817
3818 /**
3819  * Generate a fake user for emails based on support settings
3820  *
3821  */
3822 function generate_email_supportuser() {
3823
3824     global $CFG;
3825
3826     static $supportuser;
3827
3828     if (!empty($supportuser)) {
3829         return $supportuser;
3830     }
3831
3832     $supportuser = new object;
3833     $supportuser->email = $CFG->supportemail ? $CFG->supportemail : $CFG->noreplyaddress;
3834     $supportuser->firstname = $CFG->supportname ? $CFG->supportname : get_string('noreplyname');
3835     $supportuser->lastname = '';
3836     $supportuser->maildisplay = true;
3837
3838     return $supportuser;
3839 }
3840
3841
3842 /**
3843  * Sets specified user's password and send the new password to the user via email.
3844  *
3845  * @uses $CFG
3846  * @param user $user A {@link $USER} object
3847  * @return boolean|string Returns "true" if mail was sent OK, "emailstop" if email
3848  *          was blocked by user and "false" if there was another sort of error.
3849  */
3850 function setnew_password_and_mail($user) {
3851
3852     global $CFG;
3853
3854     $site  = get_site();
3855
3856     $supportuser = generate_email_supportuser();
3857
3858     $newpassword = generate_password();
3859
3860     if (! set_field('user', 'password', md5($newpassword), 'id', $user->id) ) {
3861         trigger_error('Could not set user password!');
3862         return false;
3863     }
3864
3865     $a = new object();
3866     $a->firstname   = fullname($user, true);
3867     $a->sitename    = format_string($site->fullname);
3868     $a->username    = $user->username;
3869     $a->newpassword = $newpassword;
3870     $a->link        = $CFG->wwwroot .'/login/';
3871     $a->signoff     = generate_email_signoff();
3872
3873     $message = get_string('newusernewpasswordtext', '', $a);
3874
3875     $subject  = format_string($site->fullname) .': '. get_string('newusernewpasswordsubj');
3876
3877     return email_to_user($user, $supportuser, $subject, $message);
3878
3879 }
3880
3881 /**
3882  * Resets specified user's password and send the new password to the user via email.
3883  *
3884  * @uses $CFG
3885  * @param user $user A {@link $USER} object
3886  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3887  *          was blocked by user and "false" if there was another sort of error.
3888  */
3889 function reset_password_and_mail($user) {
3890
3891     global $CFG;
3892
3893     $site  = get_site();
3894     $supportuser = generate_email_supportuser();
3895
3896     $userauth = get_auth_plugin($user->auth);
3897     if (!$userauth->can_reset_password() or !is_enabled_auth($user->auth)) {
3898         trigger_error("Attempt to reset user password for user $user->username with Auth $user->auth.");
3899         return false;
3900     }
3901
3902     $newpassword = generate_password();
3903
3904     if (!$userauth->user_update_password(addslashes_recursive($user), addslashes($newpassword))) {
3905         error("Could not set user password!");
3906     }
3907
3908     $a = new object();
3909     $a->firstname = $user->firstname;
3910     $a->sitename = format_string($site->fullname);
3911     $a->username = $user->username;
3912     $a->newpassword = $newpassword;
3913     $a->link = $CFG->httpswwwroot .'/login/change_password.php';
3914     $a->signoff = generate_email_signoff();
3915
3916     $message = get_string('newpasswordtext', '', $a);
3917
3918     $subject  = format_string($site->fullname) .': '. get_string('changedpassword');
3919
3920     return email_to_user($user, $supportuser, $subject, $message);
3921
3922 }
3923
3924 /**
3925  * Send email to specified user with confirmation text and activation link.
3926  *
3927  * @uses $CFG
3928  * @param user $user A {@link $USER} object
3929  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3930  *          was blocked by user and "false" if there was another sort of error.
3931  */
3932  function send_confirmation_email($user) {
3933
3934     global $CFG;
3935
3936     $site = get_site();
3937     $supportuser = generate_email_supportuser();
3938
3939     $data = new object();
3940     $data->firstname = fullname($user);
3941     $data->sitename = format_string($site->fullname);
3942     $data->admin = generate_email_signoff();
3943
3944     $subject = get_string('emailconfirmationsubject', '', format_string($site->fullname));
3945
3946     $data->link = $CFG->wwwroot .'/login/confirm.php?data='. $user->secret .'/'. urlencode($user->username);
3947     $message     = get_string('emailconfirmation', '', $data);
3948     $messagehtml = text_to_html(get_string('emailconfirmation', '', $data), false, false, true);
3949
3950     $user->mailformat = 1;  // Always send HTML version as well
3951
3952     return email_to_user($user, $supportuser, $subject, $message, $messagehtml);
3953
3954 }
3955
3956 /**
3957  * send_password_change_confirmation_email.
3958  *
3959  * @uses $CFG
3960  * @param user $user A {@link $USER} object
3961  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3962  *          was blocked by user and "false" if there was another sort of error.
3963  */
3964 function send_password_change_confirmation_email($user) {
3965
3966     global $CFG;
3967
3968     $site = get_site();
3969     $supportuser = generate_email_supportuser();
3970
3971     $data = new object();
3972     $data->firstname = $user->firstname;
3973     $data->sitename = format_string($site->fullname);
3974     $data->link = $CFG->httpswwwroot .'/login/forgot_password.php?p='. $user->secret .'&s='. urlencode($user->username);
3975     $data->admin = generate_email_signoff();
3976
3977     $message = get_string('emailpasswordconfirmation', '', $data);
3978     $subject = get_string('emailpasswordconfirmationsubject', '', format_string($site->fullname));
3979
3980     return email_to_user($user, $supportuser, $subject, $message);
3981
3982 }
3983
3984 /**
3985  * send_password_change_info.
3986  *
3987  * @uses $CFG
3988  * @param user $user A {@link $USER} object
3989  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3990  *          was blocked by user and "false" if there was another sort of error.
3991  */
3992 function send_password_change_info($user) {
3993
3994     global $CFG;
3995
3996     $site = get_site();
3997     $supportuser = generate_email_supportuser();
3998     $systemcontext = get_context_instance(CONTEXT_SYSTEM);
3999
4000     $data = new object();
4001     $data->firstname = $user->firstname;
4002     $data->sitename = format_string($site->fullname);
4003     $data->admin = generate_email_signoff();
4004
4005     $userauth = get_auth_plugin($user->auth);
4006
4007     if (!is_enabled_auth($user->auth) or $user->auth == 'nologin') {
4008         $message = get_string('emailpasswordchangeinfodisabled', '', $data);
4009         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
4010         return email_to_user($user, $supportuser, $subject, $message);
4011     }
4012
4013     if ($userauth->can_change_password() and $userauth->change_password_url()) {
4014         // we have some external url for password changing
4015         $data->link .= $userauth->change_password_url();
4016
4017     } else {
4018         //no way to change password, sorry
4019         $data->link = '';
4020     }
4021
4022     if (!empty($data->link) and has_capability('moodle/user:changeownpassword', $systemcontext, $user->id)) {
4023         $message = get_string('emailpasswordchangeinfo', '', $data);
4024         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
4025     } else {
4026         $message = get_string('emailpasswordchangeinfofail', '', $data);
4027         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
4028     }
4029
4030     return email_to_user($user, $supportuser, $subject, $message);
4031
4032 }
4033
4034 /**
4035  * Check that an email is allowed.  It returns an error message if there
4036  * was a problem.
4037  *
4038  * @uses $CFG
4039  * @param  string $email Content of email
4040  * @return string|false
4041  */
4042 function email_is_not_allowed($email) {
4043
4044     global $CFG;
4045
4046     if (!empty($CFG->allowemailaddresses)) {
4047         $allowed = explode(' ', $CFG->allowemailaddresses);
4048         foreach ($allowed as $allowedpattern) {
4049             $allowedpattern = trim($allowedpattern);
4050             if (!$allowedpattern) {
4051                 continue;
4052             }
4053             if (strpos($allowedpattern, '.') === 0) {
4054                 if (strpos(strrev($email), strrev($allowedpattern)) === 0) {
4055                     // subdomains are in a form ".example.com" - matches "xxx@anything.example.com"
4056                     return false;
4057                 }
4058
4059             } else if (strpos(strrev($email), strrev('@'.$allowedpattern)) === 0) { // Match!   (bug 5250)
4060                 return false;
4061             }
4062         }
4063         return get_string('emailonlyallowed', '', $CFG->allowemailaddresses);
4064
4065     } else if (!empty($CFG->denyemailaddresses)) {
4066         $denied = explode(' ', $CFG->denyemailaddresses);
4067         foreach ($denied as $deniedpattern) {
4068             $deniedpattern = trim($deniedpattern);
4069             if (!$deniedpattern) {
4070                 continue;
4071             }
4072             if (strpos($deniedpattern, '.') === 0) {
4073                 if (strpos(strrev($email), strrev($deniedpattern)) === 0) {
4074                     // subdomains are in a form ".example.com" - matches "xxx@anything.example.com"
4075                     return get_string('emailnotallowed', '', $CFG->denyemailaddresses);
4076                 }
4077
4078             } else if (strpos(strrev($email), strrev('@'.$deniedpattern)) === 0) { // Match!   (bug 5250)
4079                 return get_string('emailnotallowed', '', $CFG->denyemailaddresses);
4080             }
4081         }
4082     }
4083
4084     return false;
4085 }
4086
4087 function email_welcome_message_to_user($course, $user=NULL) {
4088     global $CFG, $USER;
4089
4090     if (empty($user)) {
4091         if (!isloggedin()) {
4092             return false;
4093         }
4094         $user = $USER;
4095     }
4096
4097     if (!empty($course->welcomemessage)) {
4098         $subject = get_string('welcometocourse', '', format_string($course->fullname));
4099
4100         $a->coursename = $course->fullname;
4101         $a->profileurl = "$CFG->wwwroot/user/view.php?id=$USER->id&course=$course->id";
4102         //$message = get_string("welcometocoursetext", "", $a);
4103         $message = $course->welcomemessage;
4104
4105         if (! $teacher = get_teacher($course->id)) {
4106             $teacher = get_admin();
4107         }
4108         email_to_user($user, $teacher, $subject, $message);
4109     }
4110 }
4111
4112 /// FILE HANDLING  /////////////////////////////////////////////
4113
4114
4115 /**
4116  * Makes an upload directory for a particular module.
4117  *
4118  * @uses $CFG
4119  * @param int $courseid The id of the course in question - maps to id field of 'course' table.
4120  * @return string|false Returns full path to directory if successful, false if not
4121  */
4122 function make_mod_upload_directory($courseid) {
4123     global $CFG;
4124
4125     if (! $moddata = make_upload_directory($courseid .'/'. $CFG->moddata)) {
4126         return false;
4127     }
4128
4129     $strreadme = get_string('readme');
4130
4131     if (file_exists($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt')) {
4132         copy($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
4133     } else {
4134         copy($CFG->dirroot .'/lang/en_utf8/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
4135     }
4136     return $moddata;
4137 }
4138
4139 /**
4140  * Makes a directory for a particular user.
4141  *
4142  * @uses $CFG
4143  * @param int $userid The id of the user in question - maps to id field of 'user' table.
4144  * @param bool $test Whether we are only testing the return value (do not create the directory)
4145  * @return string|false Returns full path to directory if successful, false if not
4146  */
4147 function make_user_directory($userid, $test=false) {
4148     global $CFG;
4149
4150     if (is_bool($userid) || $userid < 0 || !ereg('^[0-9]{1,10}$', $userid) || $userid > 2147483647) {
4151         if (!$test) {
4152             notify("Given userid was not a valid integer! (" . gettype($userid) . " $userid)");
4153         }
4154         return false;
4155     }
4156
4157     // Generate a two-level path for the userid. First level groups them by slices of 1000 users, second level is userid
4158     $level1 = floor($userid / 1000) * 1000;
4159
4160     $userdir = "user/$level1/$userid";
4161     if ($test) {
4162         return $CFG->dataroot . '/' . $userdir;
4163     } else {
4164         return make_upload_directory($userdir);
4165     }
4166 }
4167
4168 /**
4169  * Returns an array of full paths to user directories, indexed by their userids.
4170  *
4171  * @param bool $only_non_empty Only return directories that contain files
4172  * @param bool $legacy Search for user directories in legacy location (dataroot/users/userid) instead of (dataroot/user/section/userid)
4173  * @return array An associative array: userid=>array(basedir => $basedir, userfolder => $userfolder)
4174  */
4175 function get_user_directories($only_non_empty=true, $legacy=false) {
4176     global $CFG;
4177
4178     $rootdir = $CFG->dataroot."/user";
4179
4180     if ($legacy) {
4181         $rootdir = $CFG->dataroot."/users";
4182     }
4183     $dirlist = array();
4184
4185     //Check if directory exists
4186     if (check_dir_exists($rootdir, true)) {
4187         if ($legacy) {
4188             if ($userlist = get_directory_list($rootdir, '', true, true, false)) {
4189                 foreach ($userlist as $userid) {
4190                     $dirlist[$userid] = array('basedir' => $rootdir, 'userfolder' => $userid);
4191                 }
4192             } else {
4193                 notify("no directories found under $rootdir");
4194             }
4195         } else {
4196             if ($grouplist =get_directory_list($rootdir, '', true, true, false)) { // directories will be in the form 0, 1000, 2000 etc...
4197                 foreach ($grouplist as $group) {
4198                     if ($userlist = get_directory_list("$rootdir/$group", '', true, true, false)) {
4199                         foreach ($userlist as $userid) {
4200                             $dirlist[$userid] = array('basedir' => $rootdir, 'userfolder' => $group . '/' . $userid);
4201                         }
4202                     }
4203                 }
4204             }
4205         }
4206     } else {
4207         notify("$rootdir does not exist!");
4208         return false;
4209     }
4210     return $dirlist;
4211 }
4212
4213 /**
4214  * Returns current name of file on disk if it exists.
4215  *
4216  * @param string $newfile File to be verified
4217  * @return string Current name of file on disk if true
4218  */
4219 function valid_uploaded_file($newfile) {
4220     if (empty($newfile)) {
4221         return '';
4222     }
4223     if (is_uploaded_file($newfile['tmp_name']) and $newfile['size'] > 0) {
4224         return $newfile['tmp_name'];
4225     } else {
4226         return '';
4227     }
4228 }
4229
4230 /**
4231  * Returns the maximum size for uploading files.
4232  *
4233  * There are seven possible upload limits:
4234  * 1. in Apache using LimitRequestBody (no way of checking or changing this)
4235  * 2. in php.ini for 'upload_max_filesize' (can not be changed inside PHP)
4236  * 3. in .htaccess for 'upload_max_filesize' (can not be changed inside PHP)
4237  * 4. in php.ini for 'post_max_size' (can not be changed inside PHP)
4238  * 5. by the Moodle admin in $CFG->maxbytes
4239  * 6. by the teacher in the current course $course->maxbytes
4240  * 7. by the teacher for the current module, eg $assignment->maxbytes
4241  *
4242  * These last two are passed to this function as arguments (in bytes).
4243  * Anything defined as 0 is ignored.
4244  * The smallest of all the non-zero numbers is returned.
4245  *
4246  * @param int $sizebytes ?
4247  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4248  * @param int $modulebytes Current module ->maxbytes (in bytes)
4249  * @return int The maximum size for uploading files.
4250  * @todo Finish documenting this function
4251  */
4252 function get_max_upload_file_size($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4253
4254     if (! $filesize = ini_get('upload_max_filesize')) {
4255         $filesize = '5M';
4256     }
4257     $minimumsize = get_real_size($filesize);
4258
4259     if ($postsize = ini_get('post_max_size')) {
4260         $postsize = get_real_size($postsize);
4261         if ($postsize < $minimumsize) {
4262             $minimumsize = $postsize;
4263         }
4264     }
4265
4266     if ($sitebytes and $sitebytes < $minimumsize) {
4267         $minimumsize = $sitebytes;
4268     }
4269
4270     if ($coursebytes and $coursebytes < $minimumsize) {
4271         $minimumsize = $coursebytes;
4272     }
4273
4274     if ($modulebytes and $modulebytes < $minimumsize) {
4275         $minimumsize = $modulebytes;
4276     }
4277
4278     return $minimumsize;
4279 }
4280
4281 /**
4282  * Related to {@link get_max_upload_file_size()} - this function returns an
4283  * array of possible sizes in an array, translated to the
4284  * local language.
4285  *
4286  * @uses SORT_NUMERIC
4287  * @param int $sizebytes ?
4288  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4289  * @param int $modulebytes Current module ->maxbytes (in bytes)
4290  * @return int
4291  * @todo Finish documenting this function
4292  */
4293 function get_max_upload_sizes($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4294     global $CFG;
4295
4296     if (!$maxsize = get_max_upload_file_size($sitebytes, $coursebytes, $modulebytes)) {
4297         return array();
4298     }
4299
4300     $filesize[$maxsize] = display_size($maxsize);
4301
4302     $sizelist = array(10240, 51200, 102400, 512000, 1048576, 2097152,
4303                       5242880, 10485760, 20971520, 52428800, 104857600);
4304
4305     // Allow maxbytes to be selected if it falls outside the above boundaries
4306     if( isset($CFG->maxbytes) && !in_array($CFG->maxbytes, $sizelist) ){
4307             $sizelist[] = $CFG->maxbytes;
4308     }
4309
4310     foreach ($sizelist as $sizebytes) {
4311        if ($sizebytes < $maxsize) {
4312            $filesize[$sizebytes] = display_size($sizebytes);
4313        }
4314     }
4315
4316     krsort($filesize, SORT_NUMERIC);
4317
4318     return $filesize;
4319 }
4320
4321 /**
4322  * If there has been an error uploading a file, print the appropriate error message
4323  * Numerical constants used as constant definitions not added until PHP version 4.2.0
4324  *
4325  * $filearray is a 1-dimensional sub-array of the $_FILES array
4326  * eg $filearray = $_FILES['userfile1']
4327  * If left empty then the first element of the $_FILES array will be used
4328  *
4329  * @uses $_FILES
4330  * @param array $filearray  A 1-dimensional sub-array of the $_FILES array
4331  * @param bool $returnerror If true then a string error message will be returned. Otherwise the user will be notified of the error in a notify() call.
4332  * @return bool|string
4333  */
4334 function print_file_upload_error($filearray = '', $returnerror = false) {
4335
4336     if ($filearray == '' or !isset($filearray['error'])) {
4337
4338         if (empty($_FILES)) return false;
4339
4340         $files = $_FILES; /// so we don't mess up the _FILES array for subsequent code
4341         $filearray = array_shift($files); /// use first element of array
4342     }
4343
4344     switch ($filearray['error']) {
4345
4346         case 0: // UPLOAD_ERR_OK
4347             if ($filearray['size'] > 0) {
4348                 $errmessage = get_string('uploadproblem', $filearray['name']);
4349             } else {
4350                 $errmessage = get_string('uploadnofilefound'); /// probably a dud file name
4351             }
4352             break;
4353
4354         case 1: // UPLOAD_ERR_INI_SIZE
4355             $errmessage = get_string('uploadserverlimit');
4356             break;
4357
4358         case 2: // UPLOAD_ERR_FORM_SIZE
4359             $errmessage = get_string('uploadformlimit');
4360             break;
4361
4362         case 3: // UPLOAD_ERR_PARTIAL
4363             $errmessage = get_string('uploadpartialfile');
4364             break;
4365
4366         case 4: // UPLOAD_ERR_NO_FILE
4367             $errmessage = get_string('uploadnofilefound');
4368             break;
4369
4370         default:
4371             $errmessage = get_string('uploadproblem', $filearray['name']);
4372     }
4373
4374     if ($returnerror) {
4375         return $errmessage;
4376     } else {
4377         notify($errmessage);
4378         return true;
4379     }
4380
4381 }
4382
4383 /**
4384  * handy function to loop through an array of files and resolve any filename conflicts
4385  * both in the array of filenames and for what is already on disk.
4386  * not really compatible with the similar function in uploadlib.php
4387  * but this could be used for files/index.php for moving files around.
4388  */
4389
4390 function resolve_filename_collisions($destination,$files,$format='%s_%d.%s') {
4391     foreach ($files as $k => $f) {
4392         if (check_potential_filename($destination,$f,$files)) {
4393             $bits = explode('.', $f);
4394             for ($i = 1; true; $i++) {
4395                 $try = sprintf($format, $bits[0], $i, $bits[1]);
4396                 if (!check_potential_filename($destination,$try,$files)) {
4397                     $files[$k] = $try;
4398                     break;
4399                 }
4400             }
4401         }
4402     }
4403     return $files;
4404 }
4405
4406 /**
4407  * @used by resolve_filename_collisions
4408  */
4409 function check_potential_filename($destination,$filename,$files) {
4410     if (file_exists($destination.'/'.$filename)) {
4411         return true;
4412     }
4413     if (count(array_keys($files,$filename)) > 1) {
4414         return true;
4415     }
4416     return false;
4417 }
4418
4419
4420 /**
4421  * Returns an array with all the filenames in
4422  * all subdirectories, relative to the given rootdir.
4423  * If excludefile is defined, then that file/directory is ignored
4424  * If getdirs is true, then (sub)directories are included in the output
4425  * If getfiles is true, then files are included in the output
4426  * (at least one of these must be true!)
4427  *
4428  * @param string $rootdir  ?
4429  * @param string $excludefile  If defined then the specified file/directory is ignored
4430  * @param bool $descend  ?
4431  * @param bool $getdirs  If true then (sub)directories are included in the output
4432  * @param bool $getfiles  If true then files are included in the output
4433  * @return array An array with all the filenames in
4434  * all subdirectories, relative to the given rootdir
4435  * @todo Finish documenting this function. Add examples of $excludefile usage.
4436  */
4437 function get_directory_list($rootdir, $excludefiles='', $descend=true, $getdirs=false, $getfiles=true) {
4438
4439     $dirs = array();
4440
4441     if (!$getdirs and !$getfiles) {   // Nothing to show
4442         return $dirs;
4443     }
4444
4445     if (!is_dir($rootdir)) {          // Must be a directory
4446         return $dirs;
4447     }
4448
4449     if (!$dir = opendir($rootdir)) {  // Can't open it for some reason
4450         return $dirs;
4451     }
4452
4453     if (!is_array($excludefiles)) {
4454         $excludefiles = array($excludefiles);
4455     }
4456
4457     while (false !== ($file = readdir($dir))) {
4458         $firstchar = substr($file, 0, 1);
4459         if ($firstchar == '.' or $file == 'CVS' or in_array($file, $excludefiles)) {
4460             continue;
4461         }
4462         $fullfile = $rootdir .'/'. $file;
4463         if (filetype($fullfile) == 'dir') {
4464             if ($getdirs) {
4465                 $dirs[] = $file;
4466             }
4467             if ($descend) {
4468                 $subdirs = get_directory_list($fullfile, $excludefiles, $descend, $getdirs, $getfiles);
4469                 foreach ($subdirs as $subdir) {
4470                     $dirs[] = $file .'/'. $subdir;
4471                 }
4472             }
4473         } else if ($getfiles) {
4474             $dirs[] = $file;
4475         }
4476     }
4477     closedir($dir);
4478
4479     asort($dirs);
4480
4481     return $dirs;
4482 }
4483
4484
4485 /**
4486  * Adds up all the files in a directory and works out the size.
4487  *
4488  * @param string $rootdir  ?
4489  * @param string $excludefile  ?
4490  * @return array
4491  * @todo Finish documenting this function
4492  */
4493 function get_directory_size($rootdir, $excludefile='') {
4494
4495     global $CFG;
4496
4497     // do it this way if we can, it's much faster
4498     if (!empty($CFG->pathtodu) && is_executable(trim($CFG->pathtodu))) {
4499         $command = trim($CFG->pathtodu).' -sk --apparent-size '.escapeshellarg($rootdir);
4500         $output = null;
4501         $return = null;
4502         exec($command,$output,$return);
4503         if (is_array($output)) {
4504             return get_real_size(intval($output[0]).'k'); // we told it to return k.
4505         }
4506     }
4507
4508     if (!is_dir($rootdir)) {          // Must be a directory
4509         return 0;
4510     }
4511
4512     if (!$dir = @opendir($rootdir)) {  // Can't open it for some reason
4513         return 0;
4514     }
4515
4516     $size = 0;
4517
4518     while (false !== ($file = readdir($dir))) {
4519         $firstchar = substr($file, 0, 1);
4520         if ($firstchar == '.' or $file == 'CVS' or $file == $excludefile) {
4521             continue;
4522         }
4523         $fullfile = $rootdir .'/'. $file;
4524         if (filetype($fullfile) == 'dir') {
4525             $size += get_directory_size($fullfile, $excludefile);
4526         } else {
4527             $size += filesize($fullfile);
4528         }
4529     }
4530     closedir($dir);
4531
4532     return $size;
4533 }
4534
4535 /**
4536  * Converts bytes into display form
4537  *
4538  * @param string $size  ?
4539  * @return string
4540  * @staticvar string $gb Localized string for size in gigabytes
4541  * @staticvar string $mb Localized string for size in megabytes
4542  * @staticvar string $kb Localized string for size in kilobytes
4543  * @staticvar string $b Localized string for size in bytes
4544  * @todo Finish documenting this function. Verify return type.
4545  */
4546 function display_size($size) {
4547
4548     static $gb, $mb, $kb, $b;
4549
4550     if (empty($gb)) {
4551         $gb = get_string('sizegb');
4552         $mb = get_string('sizemb');
4553         $kb = get_string('sizekb');
4554         $b  = get_string('sizeb');
4555     }
4556
4557     if ($size >= 1073741824) {
4558         $size = round($size / 1073741824 * 10) / 10 . $gb;
4559     } else if ($size >= 1048576) {
4560         $size = round($size / 1048576 * 10) / 10 . $mb;
4561     } else if ($size >= 1024) {
4562         $size = round($size / 1024 * 10) / 10 . $kb;
4563     } else {
4564         $size = $size .' '. $b;
4565     }
4566     return $size;
4567 }
4568
4569 /**
4570  * Cleans a given filename by removing suspicious or troublesome characters
4571  * Only these are allowed: alphanumeric _ - .
4572  * Unicode characters can be enabled by setting $CFG->unicodecleanfilename = true in config.php
4573  *
4574  * WARNING: unicode characters may not be compatible with zip compression in backup/restore,
4575  *          because native zip binaries do weird character conversions. Use PHP zipping instead.
4576  *
4577  * @param string $string  file name
4578  * @return string cleaned file name
4579  */
4580 function clean_filename($string) {
4581     global $CFG;
4582     if (empty($CFG->unicodecleanfilename)) {
4583         $textlib = textlib_get_instance();
4584         $string = $textlib->specialtoascii($string);
4585         $string = preg_replace('/[^\.a-zA-Z\d\_-]/','_', $string ); // only allowed chars
4586     } else {
4587         //clean only ascii range
4588         $string = preg_replace("/[\\000-\\x2c\\x2f\\x3a-\\x40\\x5b-\\x5e\\x60\\x7b-\\177]/s", '_', $string);
4589     }
4590     $string = preg_replace("/_+/", '_', $string);
4591     $string = preg_replace("/\.\.+/", '.', $string);
4592     return $string;
4593 }
4594
4595
4596 /// STRING TRANSLATION  ////////////////////////////////////////
4597
4598 /**
4599  * Returns the code for the current language
4600  *
4601  * @uses $CFG
4602  * @param $USER
4603  * @param $SESSION
4604  * @return string
4605  */
4606 function current_language() {
4607     global $CFG, $USER, $SESSION, $COURSE;
4608
4609     if (!empty($COURSE->id) and $COURSE->id != SITEID and !empty($COURSE->lang)) {    // Course language can override all other settings for this page
4610         $return = $COURSE->lang;
4611
4612     } else if (!empty($SESSION->lang)) {    // Session language can override other settings
4613         $return = $SESSION->lang;
4614
4615     } else if (!empty($USER->lang)) {
4616         $return = $USER->lang;
4617
4618     } else {
4619         $return = $CFG->lang;
4620     }
4621
4622     if ($return == 'en') {
4623         $return = 'en_utf8';
4624     }
4625
4626     return $return;
4627 }
4628
4629 /**
4630  * Prints out a translated string.
4631  *
4632  * Prints out a translated string using the return value from the {@link get_string()} function.
4633  *
4634  * Example usage of this function when the string is in the moodle.php file:<br/>
4635  * <code>
4636  * echo '<strong>';
4637  * print_string('wordforstudent');
4638  * echo '</strong>';
4639  * </code>
4640  *
4641  * Example usage of this function when the string is not in the moodle.php file:<br/>
4642  * <code>
4643  * echo '<h1>';
4644  * print_string('typecourse', 'calendar');
4645  * echo '</h1>';
4646  * </code>
4647  *
4648  * @param string $identifier The key identifier for the localized string
4649  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4650  * @param mixed $a An object, string or number that can be used
4651  * within translation strings
4652  */
4653 function print_string($identifier, $module='', $a=NULL) {
4654     echo get_string($identifier, $module, $a);
4655 }
4656
4657 /**
4658  * fix up the optional data in get_string()/print_string() etc
4659  * ensure possible sprintf() format characters are escaped correctly
4660  * needs to handle arbitrary strings and objects
4661  * @param mixed $a An object, string or number that can be used
4662  * @return mixed the supplied parameter 'cleaned'
4663  */
4664 function clean_getstring_data( $a ) {
4665     if (is_string($a)) {
4666         return str_replace( '%','%%',$a );
4667     }
4668     elseif (is_object($a)) {
4669         $a_vars = get_object_vars( $a );
4670         $new_a_vars = array();
4671         foreach ($a_vars as $fname => $a_var) {
4672             $new_a_vars[$fname] = clean_getstring_data( $a_var );
4673         }
4674         return (object)$new_a_vars;
4675     }
4676     else {
4677         return $a;
4678     }
4679 }
4680
4681 /**
4682  * @return array places to look for lang strings based on the prefix to the
4683  * module name. For example qtype_ in question/type. Used by get_string and
4684  * help.php.
4685  */
4686 function places_to_search_for_lang_strings() {
4687     global $CFG;
4688
4689     return array(
4690         '__exceptions' => array('moodle', 'langconfig'),
4691         'assignment_' => array('mod/assignment/type'),
4692         'auth_' => array('auth'),
4693         'block_' => array('blocks'),
4694         'datafield_' => array('mod/data/field'),
4695         'datapreset_' => array('mod/data/preset'),
4696         'enrol_' => array('enrol'),
4697         'format_' => array('course/format'),
4698         'qtype_' => array('question/type'),
4699         'report_' => array($CFG->admin.'/report', 'course/report', 'mod/quiz/report'),
4700         'resource_' => array('mod/resource/type'),
4701         'gradereport_' => array('grade/report'),
4702         'gradeimport_' => array('grade/import'),
4703         'gradeexport_' => array('grade/export'),
4704         '' => array('mod')
4705     );
4706 }
4707
4708 /**
4709  * Returns a localized string.
4710  *
4711  * Returns the translated string specified by $identifier as
4712  * for $module.  Uses the same format files as STphp.
4713  * $a is an object, string or number that can be used
4714  * within translation strings
4715  *
4716  * eg "hello \$a->firstname \$a->lastname"
4717  * or "hello \$a"
4718  *
4719  * If you would like to directly echo the localized string use
4720  * the function {@link print_string()}
4721  *
4722  * Example usage of this function involves finding the string you would
4723  * like a local equivalent of and using its identifier and module information
4724  * to retrive it.<br/>
4725  * If you open moodle/lang/en/moodle.php and look near line 1031
4726  * you will find a string to prompt a user for their word for student
4727  * <code>
4728  * $string['wordforstudent'] = 'Your word for Student';
4729  * </code>
4730  * So if you want to display the string 'Your word for student'
4731  * in any language that supports it on your site
4732  * you just need to use the identifier 'wordforstudent'
4733  * <code>
4734  * $mystring = '<strong>'. get_string('wordforstudent') .'</strong>';
4735 or
4736  * </code>
4737  * If the string you want is in another file you'd take a slightly
4738  * different approach. Looking in moodle/lang/en/calendar.php you find
4739  * around line 75:
4740  * <code>
4741  * $string['typecourse'] = 'Course event';
4742  * </code>
4743  * If you want to display the string "Course event" in any language
4744  * supported you would use the identifier 'typecourse' and the module 'calendar'
4745  * (because it is in the file calendar.php):
4746  * <code>
4747  * $mystring = '<h1>'. get_string('typecourse', 'calendar') .'</h1>';
4748  * </code>
4749  *
4750  * As a last resort, should the identifier fail to map to a string
4751  * the returned string will be [[ $identifier ]]
4752  *
4753  * @uses $CFG
4754  * @param string $identifier The key identifier for the localized string
4755  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4756  * @param mixed $a An object, string or number that can be used
4757  * within translation strings
4758  * @param array $extralocations An array of strings with other locations to look for string files
4759  * @return string The localized string.
4760  */
4761 function get_string($identifier, $module='', $a=NULL, $extralocations=NULL) {
4762
4763     global $CFG;
4764
4765 /// originally these special strings were stored in moodle.php now we are only in langconfig.php
4766     $langconfigstrs = array('alphabet', 'backupnameformat', 'decsep', 'firstdayofweek', 'listsep', 'locale',
4767                             'localewin', 'localewincharset', 'oldcharset',
4768                             'parentlanguage', 'strftimedate', 'strftimedateshort', 'strftimedatetime',
4769                             'strftimedaydate', 'strftimedaydatetime', 'strftimedayshort', 'strftimedaytime',
4770                             'strftimemonthyear', 'strftimerecent', 'strftimerecentfull', 'strftimetime',
4771                             'thischarset', 'thisdirection', 'thislanguage');
4772
4773     $filetocheck = 'langconfig.php';
4774     $defaultlang = 'en_utf8';
4775     if (in_array($identifier, $langconfigstrs)) {
4776         $module = 'langconfig';  //This strings are under langconfig.php for 1.6 lang packs
4777     }
4778
4779     $lang = current_language();
4780
4781     if ($module == '') {
4782         $module = 'moodle';
4783     }
4784
4785     // if $a happens to have % in it, double it so sprintf() doesn't break
4786     if ($a) {
4787         $a = clean_getstring_data( $a );
4788     }
4789
4790 /// Define the two or three major locations of language strings for this module
4791     $locations = array();
4792
4793     if (!empty($extralocations)) {   // Calling code has a good idea where to look
4794         if (is_array($extralocations)) {
4795             $locations += $extralocations;
4796         } else if (is_string($extralocations)) {
4797             $locations[] = $extralocations;
4798         } else {
4799             debugging('Bad lang path provided');
4800         }
4801     }
4802
4803     if (isset($CFG->running_installer)) {
4804         $module = 'installer';
4805         $filetocheck = 'installer.php';
4806         $locations[] = $CFG->dirroot.'/install/lang/';
4807         $locations[] = $CFG->dataroot.'/lang/';
4808         $locations[] = $CFG->dirroot.'/lang/';
4809         $defaultlang = 'en_utf8';
4810     } else {
4811         $locations[] = $CFG->dataroot.'/lang/';
4812         $locations[] = $CFG->dirroot.'/lang/';
4813     }
4814
4815 /// Add extra places to look for strings for particular plugin types.
4816     $rules = places_to_search_for_lang_strings();
4817     $exceptions = $rules['__exceptions'];
4818     unset($rules['__exceptions']);
4819
4820     if (!in_array($module, $exceptions)) {
4821         $dividerpos = strpos($module, '_');
4822         if ($dividerpos === false) {
4823             $type = '';
4824             $plugin = $module;
4825         } else {
4826             $type = substr($module, 0, $dividerpos + 1);
4827             $plugin = substr($module, $dividerpos + 1);
4828         }
4829         if (!empty($rules[$type])) {
4830             foreach ($rules[$type] as $location) {
4831                 $locations[] = $CFG->dirroot . "/$location/$plugin/lang/";
4832             }
4833         }
4834     }
4835
4836 /// First check all the normal locations for the string in the current language
4837     $resultstring = '';
4838     foreach ($locations as $location) {
4839         $locallangfile = $location.$lang.'_local'.'/'.$module.'.php';    //first, see if there's a local file
4840         if (file_exists($locallangfile)) {
4841             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4842                 eval($result);
4843                 return $resultstring;
4844             }
4845         }
4846         //if local directory not found, or particular string does not exist in local direcotry
4847         $langfile = $location.$lang.'/'.$module.'.php';
4848         if (file_exists($langfile)) {
4849             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4850                 eval($result);
4851                 return $resultstring;
4852             }
4853        }
4854     }
4855
4856 /// If the preferred language was English (utf8) we can abort now
4857 /// saving some checks beacuse it's the only "root" lang
4858     if ($lang == 'en_utf8') {
4859         return '[['. $identifier .']]';
4860     }
4861
4862 /// Is a parent language defined?  If so, try to find this string in a parent language file
4863
4864     foreach ($locations as $location) {
4865         $langfile = $location.$lang.'/'.$filetocheck;
4866         if (file_exists($langfile)) {
4867             if ($result = get_string_from_file('parentlanguage', $langfile, "\$parentlang")) {
4868                 eval($result);
4869                 if (!empty($parentlang)) {   // found it!
4870
4871                     //first, see if there's a local file for parent
4872                     $locallangfile = $location.$parentlang.'_local'.'/'.$module.'.php';
4873                     if (file_exists($locallangfile)) {
4874                         if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4875                             eval($result);
4876                             return $resultstring;
4877                         }
4878                     }
4879
4880                     //if local directory not found, or particular string does not exist in local direcotry
4881                     $langfile = $location.$parentlang.'/'.$module.'.php';
4882                     if (file_exists($langfile)) {
4883                         if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4884                             eval($result);
4885                             return $resultstring;
4886                         }
4887                     }
4888                 }
4889             }
4890         }
4891     }
4892
4893 /// Our only remaining option is to try English
4894
4895     foreach ($locations as $location) {
4896         $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4897         if (file_exists($locallangfile)) {
4898             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4899                 eval($result);
4900                 return $resultstring;
4901             }
4902         }
4903
4904         //if local_en not found, or string not found in local_en
4905         $langfile = $location.$defaultlang.'/'.$module.'.php';
4906
4907         if (file_exists($langfile)) {
4908             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4909                 eval($result);
4910                 return $resultstring;
4911             }
4912         }
4913     }
4914
4915 /// And, because under 1.6 en is defined as en_utf8 child, me must try
4916 /// if it hasn't been queried before.
4917     if ($defaultlang  == 'en') {
4918         $defaultlang = 'en_utf8';
4919         foreach ($locations as $location) {
4920             $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4921             if (file_exists($locallangfile)) {
4922                 if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4923                     eval($result);
4924                     return $resultstring;
4925                 }
4926             }
4927
4928             //if local_en not found, or string not found in local_en
4929             $langfile = $location.$defaultlang.'/'.$module.'.php';
4930
4931             if (file_exists($langfile)) {
4932                 if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4933                     eval($result);
4934                     return $resultstring;
4935                 }
4936             }
4937         }
4938     }
4939
4940     return '[['.$identifier.']]';  // Last resort
4941 }
4942
4943 /**
4944  * This function is only used from {@link get_string()}.
4945  *
4946  * @internal Only used from get_string, not meant to be public API
4947  * @param string $identifier ?
4948  * @param string $langfile ?
4949  * @param string $destination ?
4950  * @return string|false ?
4951  * @staticvar array $strings Localized strings
4952  * @access private
4953  * @todo Finish documenting this function.
4954  */
4955 function get_string_from_file($identifier, $langfile, $destination) {
4956
4957     static $strings;    // Keep the strings cached in memory.
4958
4959     if (empty($strings[$langfile])) {
4960         $string = array();
4961         include ($langfile);
4962         $strings[$langfile] = $string;
4963     } else {
4964         $string = &$strings[$langfile];
4965     }
4966
4967     if (!isset ($string[$identifier])) {
4968         return false;
4969     }
4970
4971     return $destination .'= sprintf("'. $string[$identifier] .'");';
4972 }
4973
4974 /**
4975  * Converts an array of strings to their localized value.
4976  *
4977  * @param array $array An array of strings
4978  * @param string $module The language module that these strings can be found in.
4979  * @return string
4980  */
4981 function get_strings($array, $module='') {
4982
4983    $string = NULL;
4984    foreach ($array as $item) {
4985        $string->$item = get_string($item, $module);
4986    }
4987    return $string;
4988 }
4989
4990 /**
4991  * Returns a list of language codes and their full names
4992  * hides the _local files from everyone.
4993  * @param bool refreshcache force refreshing of lang cache
4994  * @param bool returnall ignore langlist, return all languages available
4995  * @return array An associative array with contents in the form of LanguageCode => LanguageName
4996  */
4997 function get_list_of_languages($refreshcache=false, $returnall=false) {
4998
4999     global $CFG;
5000
5001     $languages = array();
5002
5003     $filetocheck = 'langconfig.php';
5004
5005     if (!$refreshcache && !$returnall && !empty($CFG->langcache) && file_exists($CFG->dataroot .'/cache/languages')) {
5006 /// read available langs from cache
5007
5008         $lines = file($CFG->dataroot .'/cache/languages');
5009         foreach ($lines as $line) {
5010             $line = trim($line);
5011             if (preg_match('/^(\w+)\s+(.+)/', $line, $matches)) {
5012                 $languages[$matches[1]] = $matches[2];
5013             }
5014         }
5015         unset($lines); unset($line); unset($matches);
5016         return $languages;
5017     }
5018
5019     if (!$returnall && !empty($CFG->langlist)) {
5020 /// return only languages allowed in langlist admin setting
5021
5022         $langlist = explode(',', $CFG->langlist);
5023         // fix short lang names first - non existing langs are skipped anyway...
5024         foreach ($langlist as $lang) {
5025             if (strpos($lang, '_utf8') === false) {
5026                 $langlist[] = $lang.'_utf8';
5027             }
5028         }
5029         // find existing langs from langlist
5030         foreach ($langlist as $lang) {
5031             $lang = trim($lang);   //Just trim spaces to be a bit more permissive
5032             if (strstr($lang, '_local')!==false) {
5033                 continue;
5034             }
5035             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
5036                 $shortlang = substr($lang, 0, -5);
5037             } else {
5038                 $shortlang = $lang;
5039             }
5040         /// Search under dirroot/lang
5041             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
5042                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
5043                 if (!empty($string['thislanguage'])) {
5044                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
5045                 }
5046                 unset($string);
5047             }
5048         /// And moodledata/lang
5049             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
5050                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
5051                 if (!empty($string['thislanguage'])) {
5052                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
5053                 }
5054                 unset($string);
5055             }
5056         }
5057
5058     } else {
5059 /// return all languages available in system
5060     /// Fetch langs from moodle/lang directory
5061         $langdirs = get_list_of_plugins('lang');
5062     /// Fetch langs from moodledata/lang directory
5063         $langdirs2 = get_list_of_plugins('lang', '', $CFG->dataroot);
5064     /// Merge both lists of langs
5065         $langdirs = array_merge($langdirs, $langdirs2);
5066     /// Sort all
5067         asort($langdirs);
5068     /// Get some info from each lang (first from moodledata, then from moodle)
5069         foreach ($langdirs as $lang) {
5070             if (strstr($lang, '_local')!==false) {
5071                 continue;
5072             }
5073             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
5074                 $shortlang = substr($lang, 0, -5);
5075             } else {
5076                 $shortlang = $lang;
5077             }
5078         /// Search under moodledata/lang
5079             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
5080                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
5081                 if (!empty($string['thislanguage'])) {
5082                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
5083                 }
5084                 unset($string);
5085             }
5086         /// And dirroot/lang
5087             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
5088                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
5089                 if (!empty($string['thislanguage'])) {
5090                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
5091                 }
5092                 unset($string);
5093             }
5094         }
5095     }
5096
5097     if ($refreshcache && !empty($CFG->langcache)) {
5098         if ($returnall) {
5099             // we have a list of all langs only, just delete old cache
5100             @unlink($CFG->dataroot.'/cache/languages');
5101
5102         } else {
5103             // store the list of allowed languages
5104             if ($file = fopen($CFG->dataroot .'/cache/languages', 'w')) {
5105                 foreach ($languages as $key => $value) {
5106                     fwrite($file, "$key $value\n");
5107                 }
5108                 fclose($file);
5109             }
5110         }
5111     }
5112
5113     return $languages;
5114 }
5115
5116 /**
5117  * Returns a list of charset codes. It's hardcoded, so they should be added manually
5118  * (cheking that such charset is supported by the texlib library!)
5119  *
5120  * @return array And associative array with contents in the form of charset => charset
5121  */
5122 function get_list_of_charsets() {
5123
5124     $charsets = array(
5125         'EUC-JP'     => 'EUC-JP',
5126         'ISO-2022-JP'=> 'ISO-2022-JP',
5127         'ISO-8859-1' => 'ISO-8859-1',
5128         'SHIFT-JIS'  => 'SHIFT-JIS',
5129         'GB2312'     => 'GB2312',
5130         'GB18030'    => 'GB18030', // gb18030 not supported by typo and mbstring
5131         'UTF-8'      => 'UTF-8');
5132
5133     asort($charsets);
5134
5135     return $charsets;
5136 }
5137
5138 /**
5139  * Returns a list of country names in the current language
5140  *
5141  * @uses $CFG
5142  * @uses $USER
5143  * @return array
5144  */
5145 function get_list_of_countries() {
5146     global $CFG, $USER;
5147
5148     $lang = current_language();
5149
5150     if (!file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php') &&
5151         !file_exists($CFG->dataroot.'/lang/'. $lang .'/countries.php')) {
5152         if ($parentlang = get_string('parentlanguage')) {
5153             if (file_exists($CFG->dirroot .'/lang/'. $parentlang .'/countries.php') ||
5154                 file_exists($CFG->dataroot.'/lang/'. $parentlang .'/countries.php')) {
5155                 $lang = $parentlang;
5156             } else {
5157                 $lang = 'en_utf8';  // countries.php must exist in this pack
5158             }
5159         } else {
5160             $lang = 'en_utf8';  // countries.php must exist in this pack
5161         }
5162     }
5163
5164     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/countries.php')) {
5165         include($CFG->dataroot .'/lang/'. $lang .'/countries.php');
5166     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php')) {
5167         include($CFG->dirroot .'/lang/'. $lang .'/countries.php');
5168     }
5169
5170     if (!empty($string)) {
5171         asort($string);
5172     }
5173
5174     return $string;
5175 }
5176
5177 /**
5178  * Returns a list of valid and compatible themes
5179  *
5180  * @uses $CFG
5181  * @return array
5182  */
5183 function get_list_of_themes() {
5184
5185     global $CFG;
5186
5187     $themes = array();
5188
5189     if (!empty($CFG->themelist)) {       // use admin's list of themes
5190         $themelist = explode(',', $CFG->themelist);
5191     } else {
5192         $themelist = get_list_of_plugins("theme");
5193     }
5194
5195     foreach ($themelist as $key => $theme) {
5196         if (!file_exists("$CFG->themedir/$theme/config.php")) {   // bad folder
5197             continue;
5198         }
5199         $THEME = new object();    // Note this is not the global one!!  :-)
5200         include("$CFG->themedir/$theme/config.php");
5201         if (!isset($THEME->sheets)) {   // Not a valid 1.5 theme
5202             continue;
5203         }
5204         $themes[$theme] = $theme;
5205     }
5206     asort($themes);
5207
5208     return $themes;
5209 }
5210
5211
5212 /**
5213  * Returns a list of picture names in the current or specified language
5214  *
5215  * @uses $CFG
5216  * @return array
5217  */
5218 function get_list_of_pixnames($lang = '') {
5219     global $CFG;
5220
5221     if (empty($lang)) {
5222         $lang = current_language();
5223     }
5224
5225     $string = array();
5226
5227     $path = $CFG->dirroot .'/lang/en_utf8/pix.php'; // always exists
5228
5229     if (file_exists($CFG->dataroot .'/lang/'. $lang .'_local/pix.php')) {
5230         $path = $CFG->dataroot .'/lang/'. $lang .'_local/pix.php';
5231
5232     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/pix.php')) {
5233         $path = $CFG->dirroot .'/lang/'. $lang .'/pix.php';
5234
5235     } else if (file_exists($CFG->dataroot .'/lang/'. $lang .'/pix.php')) {
5236         $path = $CFG->dataroot .'/lang/'. $lang .'/pix.php';
5237
5238     } else if ($parentlang = get_string('parentlanguage') and $parentlang != '[[parentlanguage]]') {
5239         return get_list_of_pixnames($parentlang); //return pixnames from parent language instead
5240     }
5241
5242     include($path);
5243
5244     return $string;
5245 }
5246
5247 /**
5248  * Returns a list of timezones in the current language
5249  *
5250  * @uses $CFG
5251  * @return array
5252  */
5253 function get_list_of_timezones() {
5254     global $CFG;
5255
5256     static $timezones;
5257
5258     if (!empty($timezones)) {    // This function has been called recently
5259         return $timezones;
5260     }
5261
5262     $timezones = array();
5263
5264     if ($rawtimezones = get_records_sql('SELECT MAX(id), name FROM '.$CFG->prefix.'timezone GROUP BY name')) {
5265         foreach($rawtimezones as $timezone) {
5266             if (!empty($timezone->name)) {
5267                 $timezones[$timezone->name] = get_string(strtolower($timezone->name), 'timezones');
5268                 if (substr($timezones[$timezone->name], 0, 1) == '[') {  // No translation found
5269                     $timezones[$timezone->name] = $timezone->name;
5270                 }
5271             }
5272         }
5273     }
5274
5275     asort($timezones);
5276
5277     for ($i = -13; $i <= 13; $i += .5) {
5278         $tzstring = 'GMT';
5279         if ($i < 0) {
5280             $timezones[sprintf("%.1f", $i)] = $tzstring . $i;
5281         } else if ($i > 0) {
5282             $timezones[sprintf("%.1f", $i)] = $tzstring . '+' . $i;
5283         } else {
5284             $timezones[sprintf("%.1f", $i)] = $tzstring;
5285         }
5286     }
5287
5288     return $timezones;
5289 }
5290
5291 /**
5292  * Returns a list of currencies in the current language
5293  *
5294  * @uses $CFG
5295  * @uses $USER
5296  * @return array
5297  */
5298 function get_list_of_currencies() {
5299     global $CFG, $USER;
5300
5301     $lang = current_language();
5302
5303     if (!file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5304         if ($parentlang = get_string('parentlanguage')) {
5305             if (file_exists($CFG->dataroot .'/lang/'. $parentlang .'/currencies.php')) {
5306                 $lang = $parentlang;
5307             } else {
5308                 $lang = 'en_utf8';  // currencies.php must exist in this pack
5309             }
5310         } else {
5311             $lang = 'en_utf8';  // currencies.php must exist in this pack
5312         }
5313     }
5314
5315     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5316         include_once($CFG->dataroot .'/lang/'. $lang .'/currencies.php');
5317     } else {    //if en_utf8 is not installed in dataroot
5318         include_once($CFG->dirroot .'/lang/'. $lang .'/currencies.php');
5319     }
5320
5321     if (!empty($string)) {
5322         asort($string);
5323     }
5324
5325     return $string;
5326 }
5327
5328
5329
5330 /**
5331  * Can include a given document file (depends on second
5332  * parameter) or just return info about it.
5333  *
5334  * @uses $CFG
5335  * @param string $file ?
5336  * @param bool $include ?
5337  * @return ?
5338  * @todo Finish documenting this function
5339  */
5340 function document_file($file, $include=true) {
5341     global $CFG;
5342
5343     $file = clean_filename($file);
5344
5345     if (empty($file)) {
5346         return false;
5347     }
5348
5349     $langs = array(current_language(), get_string('parentlanguage'), 'en');
5350
5351     foreach ($langs as $lang) {
5352         $info = new object();
5353         $info->filepath = $CFG->dirroot .'/lang/'. $lang .'/docs/'. $file;
5354         $info->urlpath  = $CFG->wwwroot .'/lang/'. $lang .'/docs/'. $file;
5355
5356         if (file_exists($info->filepath)) {
5357             if ($include) {
5358                 include($info->filepath);
5359             }
5360             return $info;
5361         }
5362     }
5363
5364     return false;
5365 }
5366
5367 /// ENCRYPTION  ////////////////////////////////////////////////
5368
5369 /**
5370  * rc4encrypt
5371  *
5372  * @param string $data ?
5373  * @return string
5374  * @todo Finish documenting this function
5375  */
5376 function rc4encrypt($data) {
5377     $password = 'nfgjeingjk';
5378     return endecrypt($password, $data, '');
5379 }
5380
5381 /**
5382  * rc4decrypt
5383  *
5384  * @param string $data ?
5385  * @return string
5386  * @todo Finish documenting this function
5387  */
5388 function rc4decrypt($data) {
5389     $password = 'nfgjeingjk';
5390     return endecrypt($password, $data, 'de');
5391 }
5392
5393 /**
5394  * Based on a class by Mukul Sabharwal [mukulsabharwal @ yahoo.com]
5395  *
5396  * @param string $pwd ?
5397  * @param string $data ?
5398  * @param string $case ?
5399  * @return string
5400  * @todo Finish documenting this function
5401  */
5402 function endecrypt ($pwd, $data, $case) {
5403
5404     if ($case == 'de') {
5405         $data = urldecode($data);
5406     }
5407
5408     $key[] = '';
5409     $box[] = '';
5410     $temp_swap = '';
5411     $pwd_length = 0;
5412
5413     $pwd_length = strlen($pwd);
5414
5415     for ($i = 0; $i <= 255; $i++) {
5416         $key[$i] = ord(substr($pwd, ($i % $pwd_length), 1));
5417         $box[$i] = $i;
5418     }
5419
5420     $x = 0;
5421
5422     for ($i = 0; $i <= 255; $i++) {
5423         $x = ($x + $box[$i] + $key[$i]) % 256;
5424         $temp_swap = $box[$i];
5425         $box[$i] = $box[$x];
5426         $box[$x] = $temp_swap;
5427     }
5428
5429     $temp = '';
5430     $k = '';
5431
5432     $cipherby = '';
5433     $cipher = '';
5434
5435     $a = 0;
5436     $j = 0;
5437
5438     for ($i = 0; $i < strlen($data); $i++) {
5439         $a = ($a + 1) % 256;
5440         $j = ($j + $box[$a]) % 256;
5441         $temp = $box[$a];
5442         $box[$a] = $box[$j];
5443         $box[$j] = $temp;
5444         $k = $box[(($box[$a] + $box[$j]) % 256)];
5445         $cipherby = ord(substr($data, $i, 1)) ^ $k;
5446         $cipher .= chr($cipherby);
5447     }
5448
5449     if ($case == 'de') {
5450         $cipher = urldecode(urlencode($cipher));
5451     } else {
5452         $cipher = urlencode($cipher);
5453     }
5454
5455     return $cipher;
5456 }
5457
5458
5459 /// CALENDAR MANAGEMENT  ////////////////////////////////////////////////////////////////
5460
5461
5462 /**
5463  * Call this function to add an event to the calendar table
5464  *  and to call any calendar plugins
5465  *
5466  * @uses $CFG
5467  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field. The object event should include the following:
5468  *  <ul>
5469  *    <li><b>$event->name</b> - Name for the event
5470  *    <li><b>$event->description</b> - Description of the event (defaults to '')
5471  *    <li><b>$event->format</b> - Format for the description (using formatting types defined at the top of weblib.php)
5472  *    <li><b>$event->courseid</b> - The id of the course this event belongs to (0 = all courses)
5473  *    <li><b>$event->groupid</b> - The id of the group this event belongs to (0 = no group)
5474  *    <li><b>$event->userid</b> - The id of the user this event belongs to (0 = no user)
5475  *    <li><b>$event->modulename</b> - Name of the module that creates this event
5476  *    <li><b>$event->instance</b> - Instance of the module that owns this event
5477  *    <li><b>$event->eventtype</b> - The type info together with the module info could
5478  *             be used by calendar plugins to decide how to display event
5479  *    <li><b>$event->timestart</b>- Timestamp for start of event
5480  *    <li><b>$event->timeduration</b> - Duration (defaults to zero)
5481  *    <li><b>$event->visible</b> - 0 if the event should be hidden (e.g. because the activity that created it is hidden)
5482  *  </ul>
5483  * @return int The id number of the resulting record
5484  */
5485  function add_event($event) {
5486
5487     global $CFG;
5488
5489     $event->timemodified = time();
5490
5491     if (!$event->id = insert_record('event', $event)) {
5492         return false;
5493     }
5494
5495     if (!empty($CFG->calendar)) { // call the add_event function of the selected calendar
5496         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5497             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5498             $calendar_add_event = $CFG->calendar.'_add_event';
5499             if (function_exists($calendar_add_event)) {
5500                 $calendar_add_event($event);
5501             }
5502         }
5503     }
5504
5505     return $event->id;
5506 }
5507
5508 /**
5509  * Call this function to update an event in the calendar table
5510  * the event will be identified by the id field of the $event object.
5511  *
5512  * @uses $CFG
5513  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5514  * @return bool
5515  */
5516 function update_event($event) {
5517
5518     global $CFG;
5519
5520     $event->timemodified = time();
5521
5522     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5523         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5524             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5525             $calendar_update_event = $CFG->calendar.'_update_event';
5526             if (function_exists($calendar_update_event)) {
5527                 $calendar_update_event($event);
5528             }
5529         }
5530     }
5531     return update_record('event', $event);
5532 }
5533
5534 /**
5535  * Call this function to delete the event with id $id from calendar table.
5536  *
5537  * @uses $CFG
5538  * @param int $id The id of an event from the 'calendar' table.
5539  * @return array An associative array with the results from the SQL call.
5540  * @todo Verify return type
5541  */
5542 function delete_event($id) {
5543
5544     global $CFG;
5545
5546     if (!empty($CFG->calendar)) { // call the delete_event function of the selected calendar
5547         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5548             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5549             $calendar_delete_event = $CFG->calendar.'_delete_event';
5550             if (function_exists($calendar_delete_event)) {
5551                 $calendar_delete_event($id);
5552             }
5553         }
5554     }
5555     return delete_records('event', 'id', $id);
5556 }
5557
5558 /**
5559  * Call this function to hide an event in the calendar table
5560  * the event will be identified by the id field of the $event object.
5561  *
5562  * @uses $CFG
5563  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5564  * @return array An associative array with the results from the SQL call.
5565  * @todo Verify return type
5566  */
5567 function hide_event($event) {
5568     global $CFG;
5569
5570     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5571         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5572             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5573             $calendar_hide_event = $CFG->calendar.'_hide_event';
5574             if (function_exists($calendar_hide_event)) {
5575                 $calendar_hide_event($event);
5576             }
5577         }
5578     }
5579     return set_field('event', 'visible', 0, 'id', $event->id);
5580 }
5581
5582 /**
5583  * Call this function to unhide an event in the calendar table
5584  * the event will be identified by the id field of the $event object.
5585  *
5586  * @uses $CFG
5587  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5588  * @return array An associative array with the results from the SQL call.
5589  * @todo Verify return type
5590  */
5591 function show_event($event) {
5592     global $CFG;
5593
5594     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5595         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5596             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5597             $calendar_show_event = $CFG->calendar.'_show_event';
5598             if (function_exists($calendar_show_event)) {
5599                 $calendar_show_event($event);
5600             }
5601         }
5602     }
5603     return set_field('event', 'visible', 1, 'id', $event->id);
5604 }
5605
5606
5607 /// ENVIRONMENT CHECKING  ////////////////////////////////////////////////////////////
5608
5609 /**
5610  * Lists plugin directories within some directory
5611  *
5612  * @uses $CFG
5613  * @param string $plugin dir under we'll look for plugins (defaults to 'mod')
5614  * @param string $exclude dir name to exclude from the list (defaults to none)
5615  * @param string $basedir full path to the base dir where $plugin resides (defaults to $CFG->dirroot)
5616  * @return array of plugins found under the requested parameters
5617  */
5618 function get_list_of_plugins($plugin='mod', $exclude='', $basedir='') {
5619
5620     global $CFG;
5621
5622     $plugins = array();
5623
5624     if (empty($basedir)) {
5625
5626         # This switch allows us to use the appropiate theme directory - and potentialy alternatives for other plugins
5627         switch ($plugin) {
5628         case "theme":
5629             $basedir = $CFG->themedir;
5630             break;
5631
5632         default:
5633             $basedir = $CFG->dirroot .'/'. $plugin;
5634         }
5635
5636     } else {
5637         $basedir = $basedir .'/'. $plugin;
5638     }
5639
5640     if (file_exists($basedir) && filetype($basedir) == 'dir') {
5641         $dirhandle = opendir($basedir);
5642         while (false !== ($dir = readdir($dirhandle))) {
5643             $firstchar = substr($dir, 0, 1);
5644             if ($firstchar == '.' or $dir == 'CVS' or $dir == '_vti_cnf' or $dir == $exclude) {
5645                 continue;
5646             }
5647             if (filetype($basedir .'/'. $dir) != 'dir') {
5648                 continue;
5649             }
5650             $plugins[] = $dir;
5651         }
5652         closedir($dirhandle);
5653     }
5654     if ($plugins) {
5655         asort($plugins);
5656     }
5657     return $plugins;
5658 }
5659
5660 /**
5661  * Returns true if the current version of PHP is greater that the specified one.
5662  *
5663  * @param string $version The version of php being tested.
5664  * @return bool
5665  */
5666 function check_php_version($version='4.1.0') {
5667     return (version_compare(phpversion(), $version) >= 0);
5668 }
5669
5670
5671 /**
5672  * Checks to see if is a browser matches the specified
5673  * brand and is equal or better version.
5674  *
5675  * @uses $_SERVER
5676  * @param string $brand The browser identifier being tested
5677  * @param int $version The version of the browser
5678  * @return bool true if the given version is below that of the detected browser
5679  */
5680  function check_browser_version($brand='MSIE', $version=5.5) {
5681     if (empty($_SERVER['HTTP_USER_AGENT'])) {
5682         return false;
5683     }
5684
5685     $agent = $_SERVER['HTTP_USER_AGENT'];
5686
5687     switch ($brand) {
5688
5689       case 'Camino':   /// Mozilla Firefox browsers
5690
5691               if (preg_match("/Camino\/([0-9\.]+)/i", $agent, $match)) {
5692                   if (version_compare($match[1], $version) >= 0) {
5693                       return true;
5694                   }
5695               }
5696               break;
5697
5698
5699       case 'Firefox':   /// Mozilla Firefox browsers
5700
5701           if (preg_match("/Firefox\/([0-9\.]+)/i", $agent, $match)) {
5702               if (version_compare($match[1], $version) >= 0) {
5703                   return true;
5704               }
5705           }
5706           break;
5707
5708
5709       case 'Gecko':   /// Gecko based browsers
5710
5711           if (substr_count($agent, 'Camino')) {
5712               // MacOS X Camino support
5713               $version = 20041110;
5714           }
5715
5716           // the proper string - Gecko/CCYYMMDD Vendor/Version
5717           // Faster version and work-a-round No IDN problem.
5718           if (preg_match("/Gecko\/([0-9]+)/i", $agent, $match)) {
5719               if ($match[1] > $version) {
5720                       return true;
5721                   }
5722               }
5723           break;
5724
5725
5726       case 'MSIE':   /// Internet Explorer
5727
5728           if (strpos($agent, 'Opera')) {     // Reject Opera
5729               return false;
5730           }
5731           $string = explode(';', $agent);
5732           if (!isset($string[1])) {
5733               return false;
5734           }
5735           $string = explode(' ', trim($string[1]));
5736           if (!isset($string[0]) and !isset($string[1])) {
5737               return false;
5738           }
5739           if ($string[0] == $brand and (float)$string[1] >= $version ) {
5740               return true;
5741           }
5742           break;
5743
5744       case 'Opera':  /// Opera
5745
5746           if (preg_match("/Opera\/([0-9\.]+)/i", $agent, $match)) {
5747               if (version_compare($match[1], $version) >= 0) {
5748                   return true;
5749               }
5750           }
5751           break;
5752
5753       case 'Safari':  /// Safari
5754           // Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SimbianOS
5755           if (strpos($agent, 'OmniWeb')) { // Reject OmniWeb
5756               return false;
5757           } elseif (strpos($agent, 'Shiira')) { // Reject Shiira
5758               return false;
5759           } elseif (strpos($agent, 'SimbianOS')) { // Reject SimbianOS
5760               return false;
5761           }
5762
5763           if (preg_match("/AppleWebKit\/([0-9]+)/i", $agent, $match)) {
5764               if (version_compare($match[1], $version) >= 0) {
5765                   return true;
5766               }
5767           }
5768
5769           break;
5770
5771     }
5772
5773     return false;
5774 }
5775
5776 /**
5777  * This function makes the return value of ini_get consistent if you are
5778  * setting server directives through the .htaccess file in apache.
5779  * Current behavior for value set from php.ini On = 1, Off = [blank]
5780  * Current behavior for value set from .htaccess On = On, Off = Off
5781  * Contributed by jdell @ unr.edu
5782  *
5783  * @param string $ini_get_arg ?
5784  * @return bool
5785  * @todo Finish documenting this function
5786  */
5787 function ini_get_bool($ini_get_arg) {
5788     $temp = ini_get($ini_get_arg);
5789
5790     if ($temp == '1' or strtolower($temp) == 'on') {
5791         return true;
5792     }
5793     return false;
5794 }
5795
5796 /**
5797  * Compatibility stub to provide backward compatibility
5798  *
5799  * Determines if the HTML editor is enabled.
5800  * @deprecated Use {@link can_use_html_editor()} instead.
5801  */
5802  function can_use_richtext_editor() {
5803     return can_use_html_editor();
5804 }
5805
5806 /**
5807  * Determines if the HTML editor is enabled.
5808  *
5809  * This depends on site and user
5810  * settings, as well as the current browser being used.
5811  *
5812  * @return string|false Returns false if editor is not being used, otherwise
5813  * returns 'MSIE' or 'Gecko'.
5814  */
5815  function can_use_html_editor() {
5816     global $USER, $CFG;
5817
5818     if (!empty($USER->htmleditor) and !empty($CFG->htmleditor)) {
5819         if (check_browser_version('MSIE', 5.5)) {
5820             return 'MSIE';
5821         } else if (check_browser_version('Gecko', 20030516)) {
5822             return 'Gecko';
5823         }
5824     }
5825     return false;
5826 }
5827
5828 /**
5829  * Hack to find out the GD version by parsing phpinfo output
5830  *
5831  * @return int GD version (1, 2, or 0)
5832  */
5833 function check_gd_version() {
5834     $gdversion = 0;
5835
5836     if (function_exists('gd_info')){
5837         $gd_info = gd_info();
5838         if (substr_count($gd_info['GD Version'], '2.')) {
5839             $gdversion = 2;
5840         } else if (substr_count($gd_info['GD Version'], '1.')) {
5841             $gdversion = 1;
5842         }
5843
5844     } else {
5845         ob_start();
5846         phpinfo(8);
5847         $phpinfo = ob_get_contents();
5848         ob_end_clean();
5849
5850         $phpinfo = explode("\n", $phpinfo);
5851
5852
5853         foreach ($phpinfo as $text) {
5854             $parts = explode('</td>', $text);
5855             foreach ($parts as $key => $val) {
5856                 $parts[$key] = trim(strip_tags($val));
5857             }
5858             if ($parts[0] == 'GD Version') {
5859                 if (substr_count($parts[1], '2.0')) {
5860                     $parts[1] = '2.0';
5861                 }
5862                 $gdversion = intval($parts[1]);
5863             }
5864         }
5865     }
5866
5867     return $gdversion;   // 1, 2 or 0
5868 }
5869
5870 /**
5871  * Determine if moodle installation requires update
5872  *
5873  * Checks version numbers of main code and all modules to see
5874  * if there are any mismatches
5875  *
5876  * @uses $CFG
5877  * @return bool
5878  */
5879 function moodle_needs_upgrading() {
5880     global $CFG;
5881
5882     $version = null;
5883     include_once($CFG->dirroot .'/version.php');  # defines $version and upgrades
5884     if ($CFG->version) {
5885         if ($version > $CFG->version) {
5886             return true;
5887         }
5888         if ($mods = get_list_of_plugins('mod')) {
5889             foreach ($mods as $mod) {
5890                 $fullmod = $CFG->dirroot .'/mod/'. $mod;
5891                 $module = new object();
5892                 if (!is_readable($fullmod .'/version.php')) {
5893                     notify('Module "'. $mod .'" is not readable - check permissions');
5894                     continue;
5895                 }
5896                 include_once($fullmod .'/version.php');  # defines $module with version etc
5897                 if ($currmodule = get_record('modules', 'name', $mod)) {
5898                     if ($module->version > $currmodule->version) {
5899                         return true;
5900                     }
5901                 }
5902             }
5903         }
5904     } else {
5905         return true;
5906     }
5907     return false;
5908 }
5909
5910
5911 /// MISCELLANEOUS ////////////////////////////////////////////////////////////////////
5912
5913 /**
5914  * Notify admin users or admin user of any failed logins (since last notification).
5915  *
5916  * Note that this function must be only executed from the cron script
5917  * It uses the cache_flags system to store temporary records, deleting them
5918  * by name before finishing
5919  *
5920  * @uses $CFG
5921  * @uses $db
5922  * @uses HOURSECS
5923  */
5924 function notify_login_failures() {
5925     global $CFG, $db;
5926
5927     switch ($CFG->notifyloginfailures) {
5928         case 'mainadmin' :
5929             $recip = array(get_admin());
5930             break;
5931         case 'alladmins':
5932             $recip = get_admins();
5933             break;
5934     }
5935
5936     if (empty($CFG->lastnotifyfailure)) {
5937         $CFG->lastnotifyfailure=0;
5938     }
5939
5940     // we need to deal with the threshold stuff first.
5941     if (empty($CFG->notifyloginthreshold)) {
5942         $CFG->notifyloginthreshold = 10; // default to something sensible.
5943     }
5944
5945 /// Get all the IPs with more than notifyloginthreshold failures since lastnotifyfailure
5946 /// and insert them into the cache_flags temp table
5947     $iprs = get_recordset_sql("SELECT ip, count(*)
5948                                  FROM {$CFG->prefix}log
5949                                 WHERE module = 'login'
5950                                   AND action = 'error'
5951                                   AND time > $CFG->lastnotifyfailure
5952                              GROUP BY ip
5953                                HAVING count(*) >= $CFG->notifyloginthreshold");
5954     while ($iprec = rs_fetch_next_record($iprs)) {
5955         if (!empty($iprec->ip)) {
5956             set_cache_flag('login_failure_by_ip', $iprec->ip, '1', 0);
5957         }
5958     }
5959     rs_close($iprs);
5960
5961 /// Get all the INFOs with more than notifyloginthreshold failures since lastnotifyfailure
5962 /// and insert them into the cache_flags temp table
5963     $infors = get_recordset_sql("SELECT info, count(*)
5964                                    FROM {$CFG->prefix}log
5965                                   WHERE module = 'login'
5966                                     AND action = 'error'
5967                                     AND time > $CFG->lastnotifyfailure
5968                                GROUP BY info
5969                                  HAVING count(*) >= $CFG->notifyloginthreshold");
5970     while ($inforec = rs_fetch_next_record($infors)) {
5971         if (!empty($inforec->info)) {
5972             set_cache_flag('login_failure_by_info', $inforec->info, '1', 0);
5973         }
5974     }
5975     rs_close($infors);
5976
5977 /// Now, select all the login error logged records belonging to the ips and infos
5978 /// since lastnotifyfailure, that we have stored in the cache_flags table
5979     $logsrs = get_recordset_sql("SELECT l.*, u.firstname, u.lastname
5980                                    FROM {$CFG->prefix}log l
5981                                    JOIN {$CFG->prefix}cache_flags cf ON (l.ip = cf.name)
5982                               LEFT JOIN {$CFG->prefix}user u ON (l.userid = u.id)
5983                                   WHERE l.module = 'login'
5984                                     AND l.action = 'error'
5985                                     AND l.time > $CFG->lastnotifyfailure
5986                                     AND cf.flagtype = 'login_failure_by_ip'
5987                              UNION ALL
5988                                  SELECT l.*, u.firstname, u.lastname
5989                                    FROM {$CFG->prefix}log l
5990                                    JOIN {$CFG->prefix}cache_flags cf ON (l.info = cf.name)
5991                               LEFT JOIN {$CFG->prefix}user u ON (l.userid = u.id)
5992                                   WHERE l.module = 'login'
5993                                     AND l.action = 'error'
5994                                     AND l.time > $CFG->lastnotifyfailure
5995                                     AND cf.flagtype = 'login_failure_by_info'
5996                              ORDER BY time DESC");
5997
5998 /// Init some variables
5999     $count = 0;
6000     $messages = '';
6001 /// Iterate over the logs recordset
6002     while ($log = rs_fetch_next_record($logsrs)) {
6003         $log->time = userdate($log->time);
6004         $messages .= get_string('notifyloginfailuresmessage','',$log)."\n";
6005         $count++;
6006     }
6007     rs_close($logsrs);
6008
6009 /// If we haven't run in the last hour and
6010 /// we have something useful to report and we
6011 /// are actually supposed to be reporting to somebody
6012     if ((time() - HOURSECS) > $CFG->lastnotifyfailure && $count > 0 && is_array($recip) && count($recip) > 0) {
6013         $site = get_site();
6014         $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));
6015     /// Calculate the complete body of notification (start + messages + end)
6016         $body = get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot) .
6017                 (($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n" .
6018                 $messages .
6019                 "\n\n".get_string('notifyloginfailuresmessageend','',$CFG->wwwroot)."\n\n";
6020
6021     /// For each destination, send mail
6022         foreach ($recip as $admin) {
6023             mtrace('Emailing '. $admin->username .' about '. $count .' failed login attempts');
6024             email_to_user($admin,get_admin(), $subject, $body);
6025         }
6026
6027     /// Update lastnotifyfailure with current time
6028         set_config('lastnotifyfailure', time());
6029     }
6030
6031 /// Finally, delete all the temp records we have created in cache_flags
6032     delete_records_select('cache_flags', "flagtype IN ('login_failure_by_ip', 'login_failure_by_info')");
6033 }
6034
6035 /**
6036  * moodle_setlocale
6037  *
6038  * @uses $CFG
6039  * @param string $locale ?
6040  * @todo Finish documenting this function
6041  */
6042 function moodle_setlocale($locale='') {
6043
6044     global $CFG;
6045
6046     static $currentlocale = ''; // last locale caching
6047
6048     $oldlocale = $currentlocale;
6049
6050 /// Fetch the correct locale based on ostype
6051     if($CFG->ostype == 'WINDOWS') {
6052         $stringtofetch = 'localewin';
6053     } else {
6054         $stringtofetch = 'locale';
6055     }
6056
6057 /// the priority is the same as in get_string() - parameter, config, course, session, user, global language
6058     if (!empty($locale)) {
6059         $currentlocale = $locale;
6060     } else if (!empty($CFG->locale)) { // override locale for all language packs
6061         $currentlocale = $CFG->locale;
6062     } else {
6063         $currentlocale = get_string($stringtofetch);
6064     }
6065
6066 /// do nothing if locale already set up
6067     if ($oldlocale == $currentlocale) {
6068         return;
6069     }
6070
6071 /// Due to some strange BUG we cannot set the LC_TIME directly, so we fetch current values,
6072 /// set LC_ALL and then set values again. Just wondering why we cannot set LC_ALL only??? - stronk7
6073 /// Some day, numeric, monetary and other categories should be set too, I think. :-/
6074
6075 /// Get current values
6076     $monetary= setlocale (LC_MONETARY, 0);
6077     $numeric = setlocale (LC_NUMERIC, 0);
6078     $ctype   = setlocale (LC_CTYPE, 0);
6079     if ($CFG->ostype != 'WINDOWS') {
6080         $messages= setlocale (LC_MESSAGES, 0);
6081     }
6082 /// Set locale to all
6083     setlocale (LC_ALL, $currentlocale);
6084 /// Set old values
6085     setlocale (LC_MONETARY, $monetary);
6086     setlocale (LC_NUMERIC, $numeric);
6087     if ($CFG->ostype != 'WINDOWS') {
6088         setlocale (LC_MESSAGES, $messages);
6089     }
6090     if ($currentlocale == 'tr_TR' or $currentlocale == 'tr_TR.UTF-8') { // To workaround a well-known PHP problem with Turkish letter Ii
6091         setlocale (LC_CTYPE, $ctype);
6092     }
6093 }
6094
6095 /**
6096  * Converts string to lowercase using most compatible function available.
6097  *
6098  * @param string $string The string to convert to all lowercase characters.
6099  * @param string $encoding The encoding on the string.
6100  * @return string
6101  * @todo Add examples of calling this function with/without encoding types
6102  * @deprecated Use textlib->strtolower($text) instead.
6103  */
6104 function moodle_strtolower ($string, $encoding='') {
6105
6106     //If not specified use utf8
6107     if (empty($encoding)) {
6108         $encoding = 'UTF-8';
6109     }
6110     //Use text services
6111     $textlib = textlib_get_instance();
6112
6113     return $textlib->strtolower($string, $encoding);
6114 }
6115
6116 /**
6117  * Count words in a string.
6118  *
6119  * Words are defined as things between whitespace.
6120  *
6121  * @param string $string The text to be searched for words.
6122  * @return int The count of words in the specified string
6123  */
6124 function count_words($string) {
6125     $string = strip_tags($string);
6126     return count(preg_split("/\w\b/", $string)) - 1;
6127 }
6128
6129 /** Count letters in a string.
6130  *
6131  * Letters are defined as chars not in tags and different from whitespace.
6132  *
6133  * @param string $string The text to be searched for letters.
6134  * @return int The count of letters in the specified text.
6135  */
6136 function count_letters($string) {
6137 /// Loading the textlib singleton instance. We are going to need it.
6138     $textlib = textlib_get_instance();
6139
6140     $string = strip_tags($string); // Tags are out now
6141     $string = ereg_replace('[[:space:]]*','',$string); //Whitespace are out now
6142
6143     return $textlib->strlen($string);
6144 }
6145
6146 /**
6147  * Generate and return a random string of the specified length.
6148  *
6149  * @param int $length The length of the string to be created.
6150  * @return string
6151  */
6152 function random_string ($length=15) {
6153     $pool  = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
6154     $pool .= 'abcdefghijklmnopqrstuvwxyz';
6155     $pool .= '0123456789';
6156     $poollen = strlen($pool);
6157     mt_srand ((double) microtime() * 1000000);
6158     $string = '';
6159     for ($i = 0; $i < $length; $i++) {
6160         $string .= substr($pool, (mt_rand()%($poollen)), 1);
6161     }
6162     return $string;
6163 }
6164
6165 /*
6166  * Given some text (which may contain HTML) and an ideal length,
6167  * this function truncates the text neatly on a word boundary if possible
6168  */
6169 function shorten_text($text, $ideal=30) {
6170
6171    global $CFG;
6172
6173
6174    $i = 0;
6175    $tag = false;
6176    $length = strlen($text);
6177    $count = 0;
6178    $stopzone = false;
6179    $truncate = 0;
6180
6181    if ($length <= $ideal) {
6182        return $text;
6183    }
6184
6185    for ($i=0; $i<$length; $i++) {
6186        $char = $text[$i];
6187
6188        switch ($char) {
6189            case "<":
6190                $tag = true;
6191                break;
6192            case ">":
6193                $tag = false;
6194                break;
6195            default:
6196                if (!$tag) {
6197                    if ($stopzone) {
6198                        if ($char == '.' or $char == ' ') {
6199                            $truncate = $i+1;
6200                            break 2;
6201                        } else if (ord($char) >= 0xE0) {  // Chinese/Japanese/Korean text
6202                            $truncate = $i;               // can be truncated at any UTF-8
6203                            break 2;                      // character boundary.
6204                        }
6205                    }
6206                    $count++;
6207                }
6208                break;
6209        }
6210        if (!$stopzone) {
6211            if ($count > $ideal) {
6212                $stopzone = true;
6213            }
6214        }
6215    }
6216
6217    if (!$truncate) {
6218        $truncate = $i;
6219    }
6220
6221    $ellipse = ($truncate < $length) ? '...' : '';
6222
6223    return substr($text, 0, $truncate).$ellipse;
6224 }
6225
6226
6227 /**
6228  * Given dates in seconds, how many weeks is the date from startdate
6229  * The first week is 1, the second 2 etc ...
6230  *
6231  * @uses WEEKSECS
6232  * @param ? $startdate ?
6233  * @param ? $thedate ?
6234  * @return string
6235  * @todo Finish documenting this function
6236  */
6237 function getweek ($startdate, $thedate) {
6238     if ($thedate < $startdate) {   // error
6239         return 0;
6240     }
6241
6242     return floor(($thedate - $startdate) / WEEKSECS) + 1;
6243 }
6244
6245 /**
6246  * returns a randomly generated password of length $maxlen.  inspired by
6247  * {@link http://www.phpbuilder.com/columns/jesus19990502.php3}
6248  *
6249  * @param int $maxlength  The maximum size of the password being generated.
6250  * @return string
6251  */
6252 function generate_password($maxlen=10) {
6253     global $CFG;
6254
6255     $fillers = '1234567890!$-+';
6256     $wordlist = file($CFG->wordlist);
6257
6258     srand((double) microtime() * 1000000);
6259     $word1 = trim($wordlist[rand(0, count($wordlist) - 1)]);
6260     $word2 = trim($wordlist[rand(0, count($wordlist) - 1)]);
6261     $filler1 = $fillers[rand(0, strlen($fillers) - 1)];
6262
6263     return substr($word1 . $filler1 . $word2, 0, $maxlen);
6264 }
6265
6266 /**
6267  * Given a float, prints it nicely.
6268  * Localized floats must not be used in calculations!
6269  *
6270  * @param float $flaot The float to print
6271  * @param int $places The number of decimal places to print.
6272  * @param bool $localized use localized decimal separator
6273  * @return string locale float
6274  */
6275 function format_float($float, $decimalpoints=1, $localized=true) {
6276     if (is_null($float)) {
6277         return '';
6278     }
6279     if ($localized) {
6280         return number_format($float, $decimalpoints, get_string('decsep'), '');
6281     } else {
6282         return number_format($float, $decimalpoints, '.', '');
6283     }
6284 }
6285
6286 /**
6287  * Converts locale specific floating point/comma number back to standard PHP float value
6288  * Do NOT try to do any math operations before this conversion on any user submitted floats!
6289  *
6290  * @param  string $locale_float locale aware float representation
6291  */
6292 function unformat_float($locale_float) {
6293     $locale_float = trim($locale_float);
6294
6295     if ($locale_float == '') {
6296         return null;
6297     }
6298
6299     $locale_float = str_replace(' ', '', $locale_float); // no spaces - those might be used as thousand separators
6300
6301     return (float)str_replace(get_string('decsep'), '.', $locale_float);
6302 }
6303
6304 /**
6305  * Given a simple array, this shuffles it up just like shuffle()
6306  * Unlike PHP's shuffle() this function works on any machine.
6307  *
6308  * @param array $array The array to be rearranged
6309  * @return array
6310  */
6311 function swapshuffle($array) {
6312
6313     srand ((double) microtime() * 10000000);
6314     $last = count($array) - 1;
6315     for ($i=0;$i<=$last;$i++) {
6316         $from = rand(0,$last);
6317         $curr = $array[$i];
6318         $array[$i] = $array[$from];
6319         $array[$from] = $curr;
6320     }
6321     return $array;
6322 }
6323
6324 /**
6325  * Like {@link swapshuffle()}, but works on associative arrays
6326  *
6327  * @param array $array The associative array to be rearranged
6328  * @return array
6329  */
6330 function swapshuffle_assoc($array) {
6331 ///
6332
6333     $newkeys = swapshuffle(array_keys($array));
6334     foreach ($newkeys as $newkey) {
6335         $newarray[$newkey] = $array[$newkey];
6336     }
6337     return $newarray;
6338 }
6339
6340 /**
6341  * Given an arbitrary array, and a number of draws,
6342  * this function returns an array with that amount
6343  * of items.  The indexes are retained.
6344  *
6345  * @param array $array ?
6346  * @param ? $draws ?
6347  * @return ?
6348  * @todo Finish documenting this function
6349  */
6350 function draw_rand_array($array, $draws) {
6351     srand ((double) microtime() * 10000000);
6352
6353     $return = array();
6354
6355     $last = count($array);
6356
6357     if ($draws > $last) {
6358         $draws = $last;
6359     }
6360
6361     while ($draws > 0) {
6362         $last--;
6363
6364         $keys = array_keys($array);
6365         $rand = rand(0, $last);
6366
6367         $return[$keys[$rand]] = $array[$keys[$rand]];
6368         unset($array[$keys[$rand]]);
6369
6370         $draws--;
6371     }
6372
6373     return $return;
6374 }
6375
6376 /**
6377  * microtime_diff
6378  *
6379  * @param string $a ?
6380  * @param string $b ?
6381  * @return string
6382  * @todo Finish documenting this function
6383  */
6384 function microtime_diff($a, $b) {
6385     list($a_dec, $a_sec) = explode(' ', $a);
6386     list($b_dec, $b_sec) = explode(' ', $b);
6387     return $b_sec - $a_sec + $b_dec - $a_dec;
6388 }
6389
6390 /**
6391  * Given a list (eg a,b,c,d,e) this function returns
6392  * an array of 1->a, 2->b, 3->c etc
6393  *
6394  * @param array $list ?
6395  * @param string $separator ?
6396  * @todo Finish documenting this function
6397  */
6398 function make_menu_from_list($list, $separator=',') {
6399
6400     $array = array_reverse(explode($separator, $list), true);
6401     foreach ($array as $key => $item) {
6402         $outarray[$key+1] = trim($item);
6403     }
6404     return $outarray;
6405 }
6406
6407 /**
6408  * Creates an array that represents all the current grades that
6409  * can be chosen using the given grading type.  Negative numbers
6410  * are scales, zero is no grade, and positive numbers are maximum
6411  * grades.
6412  *
6413  * @param int $gradingtype ?
6414  * return int
6415  * @todo Finish documenting this function
6416  */
6417 function make_grades_menu($gradingtype) {
6418     $grades = array();
6419     if ($gradingtype < 0) {
6420         if ($scale = get_record('scale', 'id', - $gradingtype)) {
6421             return make_menu_from_list($scale->scale);
6422         }
6423     } else if ($gradingtype > 0) {
6424         for ($i=$gradingtype; $i>=0; $i--) {
6425             $grades[$i] = $i .' / '. $gradingtype;
6426         }
6427         return $grades;
6428     }
6429     return $grades;
6430 }
6431
6432 /**
6433  * This function returns the nummber of activities
6434  * using scaleid in a courseid
6435  *
6436  * @param int $courseid ?
6437  * @param int $scaleid ?
6438  * @return int
6439  * @todo Finish documenting this function
6440  */
6441 function course_scale_used($courseid, $scaleid) {
6442
6443     global $CFG;
6444
6445     $return = 0;
6446
6447     if (!empty($scaleid)) {
6448         if ($cms = get_course_mods($courseid)) {
6449             foreach ($cms as $cm) {
6450                 //Check cm->name/lib.php exists
6451                 if (file_exists($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php')) {
6452                     include_once($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php');
6453                     $function_name = $cm->modname.'_scale_used';
6454                     if (function_exists($function_name)) {
6455                         if ($function_name($cm->instance,$scaleid)) {
6456                             $return++;
6457                         }
6458                     }
6459                 }
6460             }
6461         }
6462
6463         // check if any course grade item makes use of the scale
6464         $return += count_records('grade_items', 'courseid', $courseid, 'scaleid', $scaleid);
6465     }
6466     return $return;
6467 }
6468
6469 /**
6470  * This function returns the nummber of activities
6471  * using scaleid in the entire site
6472  *
6473  * @param int $scaleid ?
6474  * @return int
6475  * @todo Finish documenting this function. Is return type correct?
6476  */
6477 function site_scale_used($scaleid,&$courses) {
6478
6479     global $CFG;
6480
6481     $return = 0;
6482
6483     if (!is_array($courses) || count($courses) == 0) {
6484         $courses = get_courses("all",false,"c.id,c.shortname");
6485     }
6486
6487     if (!empty($scaleid)) {
6488         if (is_array($courses) && count($courses) > 0) {
6489             foreach ($courses as $course) {
6490                 $return += course_scale_used($course->id,$scaleid);
6491             }
6492         }
6493     }
6494     return $return;
6495 }
6496
6497 /**
6498  * make_unique_id_code
6499  *
6500  * @param string $extra ?
6501  * @return string
6502  * @todo Finish documenting this function
6503  */
6504 function make_unique_id_code($extra='') {
6505
6506     $hostname = 'unknownhost';
6507     if (!empty($_SERVER['HTTP_HOST'])) {
6508         $hostname = $_SERVER['HTTP_HOST'];
6509     } else if (!empty($_ENV['HTTP_HOST'])) {
6510         $hostname = $_ENV['HTTP_HOST'];
6511     } else if (!empty($_SERVER['SERVER_NAME'])) {
6512         $hostname = $_SERVER['SERVER_NAME'];
6513     } else if (!empty($_ENV['SERVER_NAME'])) {
6514         $hostname = $_ENV['SERVER_NAME'];
6515     }
6516
6517     $date = gmdate("ymdHis");
6518
6519     $random =  random_string(6);
6520
6521     if ($extra) {
6522         return $hostname .'+'. $date .'+'. $random .'+'. $extra;
6523     } else {
6524         return $hostname .'+'. $date .'+'. $random;
6525     }
6526 }
6527
6528
6529 /**
6530  * Function to check the passed address is within the passed subnet
6531  *
6532  * The parameter is a comma separated string of subnet definitions.
6533  * Subnet strings can be in one of three formats:
6534  *   1: xxx.xxx.xxx.xxx/xx
6535  *   2: xxx.xxx
6536  *   3: xxx.xxx.xxx.xxx-xxx   //a range of IP addresses in the last group.
6537  * Code for type 1 modified from user posted comments by mediator at
6538  * {@link http://au.php.net/manual/en/function.ip2long.php}
6539  *
6540  * @param string $addr    The address you are checking
6541  * @param string $subnetstr    The string of subnet addresses
6542  * @return bool
6543  */
6544 function address_in_subnet($addr, $subnetstr) {
6545
6546     $subnets = explode(',', $subnetstr);
6547     $found = false;
6548     $addr = trim($addr);
6549
6550     foreach ($subnets as $subnet) {
6551         $subnet = trim($subnet);
6552         if (strpos($subnet, '/') !== false) { /// type 1
6553             list($ip, $mask) = explode('/', $subnet);
6554             $mask = 0xffffffff << (32 - $mask);
6555             $found = ((ip2long($addr) & $mask) == (ip2long($ip) & $mask));
6556         } else if (strpos($subnet, '-') !== false)  {/// type 3
6557             $subnetparts = explode('.', $subnet);
6558             $addrparts = explode('.', $addr);
6559             $subnetrange = explode('-', array_pop($subnetparts));
6560             if (count($subnetrange) == 2) {
6561                 $lastaddrpart = array_pop($addrparts);
6562                 $found = ($subnetparts == $addrparts &&
6563                         $subnetrange[0] <= $lastaddrpart && $lastaddrpart <= $subnetrange[1]);
6564             }
6565         } else { /// type 2
6566             $found = (strpos($addr, $subnet) === 0);
6567         }
6568
6569         if ($found) {
6570             break;
6571         }
6572     }
6573     return $found;
6574 }
6575
6576 /**
6577  * This function sets the $HTTPSPAGEREQUIRED global
6578  * (used in some parts of moodle to change some links)
6579  * and calculate the proper wwwroot to be used
6580  *
6581  * By using this function properly, we can ensure 100% https-ized pages
6582  * at our entire discretion (login, forgot_password, change_password)
6583  */
6584 function httpsrequired() {
6585
6586     global $CFG, $HTTPSPAGEREQUIRED;
6587
6588     if (!empty($CFG->loginhttps)) {
6589         $HTTPSPAGEREQUIRED = true;
6590         $CFG->httpswwwroot = str_replace('http:', 'https:', $CFG->wwwroot);
6591         $CFG->httpsthemewww = str_replace('http:', 'https:', $CFG->themewww);
6592
6593         // change theme URLs to https
6594         theme_setup();
6595
6596     } else {
6597         $CFG->httpswwwroot = $CFG->wwwroot;
6598         $CFG->httpsthemewww = $CFG->themewww;
6599     }
6600 }
6601
6602 /**
6603  * For outputting debugging info
6604  *
6605  * @uses STDOUT
6606  * @param string $string ?
6607  * @param string $eol ?
6608  * @todo Finish documenting this function
6609  */
6610 function mtrace($string, $eol="\n", $sleep=0) {
6611
6612     if (defined('STDOUT')) {
6613         fwrite(STDOUT, $string.$eol);
6614     } else {
6615         echo $string . $eol;
6616     }
6617
6618     flush();
6619
6620     //delay to keep message on user's screen in case of subsequent redirect
6621     if ($sleep) {
6622         sleep($sleep);
6623     }
6624 }
6625
6626 //Replace 1 or more slashes or backslashes to 1 slash
6627 function cleardoubleslashes ($path) {
6628     return preg_replace('/(\/|\\\){1,}/','/',$path);
6629 }
6630
6631 function zip_files ($originalfiles, $destination) {
6632 //Zip an array of files/dirs to a destination zip file
6633 //Both parameters must be FULL paths to the files/dirs
6634
6635     global $CFG;
6636
6637     //Extract everything from destination
6638     $path_parts = pathinfo(cleardoubleslashes($destination));
6639     $destpath = $path_parts["dirname"];       //The path of the zip file
6640     $destfilename = $path_parts["basename"];  //The name of the zip file
6641     $extension = $path_parts["extension"];    //The extension of the file
6642
6643     //If no file, error
6644     if (empty($destfilename)) {
6645         return false;
6646     }
6647
6648     //If no extension, add it
6649     if (empty($extension)) {
6650         $extension = 'zip';
6651         $destfilename = $destfilename.'.'.$extension;
6652     }
6653
6654     //Check destination path exists
6655     if (!is_dir($destpath)) {
6656         return false;
6657     }
6658
6659     //Check destination path is writable. TODO!!
6660
6661     //Clean destination filename
6662     $destfilename = clean_filename($destfilename);
6663
6664     //Now check and prepare every file
6665     $files = array();
6666     $origpath = NULL;
6667
6668     foreach ($originalfiles as $file) {  //Iterate over each file
6669         //Check for every file
6670         $tempfile = cleardoubleslashes($file); // no doubleslashes!
6671         //Calculate the base path for all files if it isn't set
6672         if ($origpath === NULL) {
6673             $origpath = rtrim(cleardoubleslashes(dirname($tempfile)), "/");
6674         }
6675         //See if the file is readable
6676         if (!is_readable($tempfile)) {  //Is readable
6677             continue;
6678         }
6679         //See if the file/dir is in the same directory than the rest
6680         if (rtrim(cleardoubleslashes(dirname($tempfile)), "/") != $origpath) {
6681             continue;
6682         }
6683         //Add the file to the array
6684         $files[] = $tempfile;
6685     }
6686
6687     //Everything is ready:
6688     //    -$origpath is the path where ALL the files to be compressed reside (dir).
6689     //    -$destpath is the destination path where the zip file will go (dir).
6690     //    -$files is an array of files/dirs to compress (fullpath)
6691     //    -$destfilename is the name of the zip file (without path)
6692
6693     //print_object($files);                  //Debug
6694
6695     if (empty($CFG->zip)) {    // Use built-in php-based zip function
6696
6697         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6698         //rewrite filenames because the old method with PCLZIP_OPT_REMOVE_PATH does not work under win32
6699         $zipfiles = array();
6700         $start = strlen($origpath)+1;
6701         foreach($files as $file) {
6702             $tf = array();
6703             $tf[PCLZIP_ATT_FILE_NAME] = $file;
6704             $tf[PCLZIP_ATT_FILE_NEW_FULL_NAME] = substr($file, $start);
6705             $zipfiles[] = $tf;
6706         }
6707         //create the archive
6708         $archive = new PclZip(cleardoubleslashes("$destpath/$destfilename"));
6709         if (($list = $archive->create($zipfiles) == 0)) {
6710             notice($archive->errorInfo(true));
6711             return false;
6712         }
6713
6714     } else {                   // Use external zip program
6715
6716         $filestozip = "";
6717         foreach ($files as $filetozip) {
6718             $filestozip .= escapeshellarg(basename($filetozip));
6719             $filestozip .= " ";
6720         }
6721         //Construct the command
6722         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6723         $command = 'cd '.escapeshellarg($origpath).$separator.
6724                     escapeshellarg($CFG->zip).' -r '.
6725                     escapeshellarg(cleardoubleslashes("$destpath/$destfilename")).' '.$filestozip;
6726         //All converted to backslashes in WIN
6727         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6728             $command = str_replace('/','\\',$command);
6729         }
6730         Exec($command);
6731     }
6732     return true;
6733 }
6734
6735 function unzip_file ($zipfile, $destination = '', $showstatus = true) {
6736 //Unzip one zip file to a destination dir
6737 //Both parameters must be FULL paths
6738 //If destination isn't specified, it will be the
6739 //SAME directory where the zip file resides.
6740
6741     global $CFG;
6742
6743     //Extract everything from zipfile
6744     $path_parts = pathinfo(cleardoubleslashes($zipfile));
6745     $zippath = $path_parts["dirname"];       //The path of the zip file
6746     $zipfilename = $path_parts["basename"];  //The name of the zip file
6747     $extension = $path_parts["extension"];    //The extension of the file
6748
6749     //If no file, error
6750     if (empty($zipfilename)) {
6751         return false;
6752     }
6753
6754     //If no extension, error
6755     if (empty($extension)) {
6756         return false;
6757     }
6758
6759     //Clear $zipfile
6760     $zipfile = cleardoubleslashes($zipfile);
6761
6762     //Check zipfile exists
6763     if (!file_exists($zipfile)) {
6764         return false;
6765     }
6766
6767     //If no destination, passed let's go with the same directory
6768     if (empty($destination)) {
6769         $destination = $zippath;
6770     }
6771
6772     //Clear $destination
6773     $destpath = rtrim(cleardoubleslashes($destination), "/");
6774
6775     //Check destination path exists
6776     if (!is_dir($destpath)) {
6777         return false;
6778     }
6779
6780     //Check destination path is writable. TODO!!
6781
6782     //Everything is ready:
6783     //    -$zippath is the path where the zip file resides (dir)
6784     //    -$zipfilename is the name of the zip file (without path)
6785     //    -$destpath is the destination path where the zip file will uncompressed (dir)
6786
6787     $list = null;
6788
6789     if (empty($CFG->unzip)) {    // Use built-in php-based unzip function
6790
6791         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6792         $archive = new PclZip(cleardoubleslashes("$zippath/$zipfilename"));
6793         if (!$list = $archive->extract(PCLZIP_OPT_PATH, $destpath,
6794                                        PCLZIP_CB_PRE_EXTRACT, 'unzip_cleanfilename',
6795                                        PCLZIP_OPT_EXTRACT_DIR_RESTRICTION, $destpath)) {
6796             notice($archive->errorInfo(true));
6797             return false;
6798         }
6799
6800     } else {                     // Use external unzip program
6801
6802         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6803         $redirection = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? '' : ' 2>&1';
6804
6805         $command = 'cd '.escapeshellarg($zippath).$separator.
6806                     escapeshellarg($CFG->unzip).' -o '.
6807                     escapeshellarg(cleardoubleslashes("$zippath/$zipfilename")).' -d '.
6808                     escapeshellarg($destpath).$redirection;
6809         //All converted to backslashes in WIN
6810         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6811             $command = str_replace('/','\\',$command);
6812         }
6813         Exec($command,$list);
6814     }
6815
6816     //Display some info about the unzip execution
6817     if ($showstatus) {
6818         unzip_show_status($list,$destpath);
6819     }
6820
6821     return true;
6822 }
6823
6824 function unzip_cleanfilename ($p_event, &$p_header) {
6825 //This function is used as callback in unzip_file() function
6826 //to clean illegal characters for given platform and to prevent directory traversal.
6827 //Produces the same result as info-zip unzip.
6828     $p_header['filename'] = ereg_replace('[[:cntrl:]]', '', $p_header['filename']); //strip control chars first!
6829     $p_header['filename'] = ereg_replace('\.\.+', '', $p_header['filename']); //directory traversal protection
6830     if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6831         $p_header['filename'] = ereg_replace('[:*"?<>|]', '_', $p_header['filename']); //replace illegal chars
6832         $p_header['filename'] = ereg_replace('^([a-zA-Z])_', '\1:', $p_header['filename']); //repair drive letter
6833     } else {
6834         //Add filtering for other systems here
6835         // BSD: none (tested)
6836         // Linux: ??
6837         // MacosX: ??
6838     }
6839     $p_header['filename'] = cleardoubleslashes($p_header['filename']); //normalize the slashes/backslashes
6840     return 1;
6841 }
6842
6843 function unzip_show_status ($list,$removepath) {
6844 //This function shows the results of the unzip execution
6845 //depending of the value of the $CFG->zip, results will be
6846 //text or an array of files.
6847
6848     global $CFG;
6849
6850     if (empty($CFG->unzip)) {    // Use built-in php-based zip function
6851         $strname = get_string("name");
6852         $strsize = get_string("size");
6853         $strmodified = get_string("modified");
6854         $strstatus = get_string("status");
6855         echo "<table width=\"640\">";
6856         echo "<tr><th class=\"header\" scope=\"col\">$strname</th>";
6857         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strsize</th>";
6858         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strmodified</th>";
6859         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strstatus</th></tr>";
6860         foreach ($list as $item) {
6861             echo "<tr>";
6862             $item['filename'] = str_replace(cleardoubleslashes($removepath).'/', "", $item['filename']);
6863             print_cell("left", s($item['filename']));
6864             if (! $item['folder']) {
6865                 print_cell("right", display_size($item['size']));
6866             } else {
6867                 echo "<td>&nbsp;</td>";
6868             }
6869             $filedate  = userdate($item['mtime'], get_string("strftimedatetime"));
6870             print_cell("right", $filedate);
6871             print_cell("right", $item['status']);
6872             echo "</tr>";
6873         }
6874         echo "</table>";
6875
6876     } else {                   // Use external zip program
6877         print_simple_box_start("center");
6878         echo "<pre>";
6879         foreach ($list as $item) {
6880             echo s(str_replace(cleardoubleslashes($removepath.'/'), '', $item)).'<br />';
6881         }
6882         echo "</pre>";
6883         print_simple_box_end();
6884     }
6885 }
6886
6887 /**
6888  * Returns most reliable client address
6889  *
6890  * @return string The remote IP address
6891  */
6892  function getremoteaddr() {
6893     if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
6894         return cleanremoteaddr($_SERVER['HTTP_CLIENT_IP']);
6895     }
6896     if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
6897         return cleanremoteaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
6898     }
6899     if (!empty($_SERVER['REMOTE_ADDR'])) {
6900         return cleanremoteaddr($_SERVER['REMOTE_ADDR']);
6901     }
6902     return '';
6903 }
6904
6905 /**
6906  * Cleans a remote address ready to put into the log table
6907  */
6908 function cleanremoteaddr($addr) {
6909     $originaladdr = $addr;
6910     $matches = array();
6911     // first get all things that look like IP addresses.
6912     if (!preg_match_all('/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/',$addr,$matches,PREG_SET_ORDER)) {
6913         return '';
6914     }
6915     $goodmatches = array();
6916     $lanmatches = array();
6917     foreach ($matches as $match) {
6918         //        print_r($match);
6919         // check to make sure it's not an internal address.
6920         // the following are reserved for private lans...
6921         // 10.0.0.0 - 10.255.255.255
6922         // 172.16.0.0 - 172.31.255.255
6923         // 192.168.0.0 - 192.168.255.255
6924         // 169.254.0.0 -169.254.255.255
6925         $bits = explode('.',$match[0]);
6926         if (count($bits) != 4) {
6927             // weird, preg match shouldn't give us it.
6928             continue;
6929         }
6930         if (($bits[0] == 10)
6931             || ($bits[0] == 172 && $bits[1] >= 16 && $bits[1] <= 31)
6932             || ($bits[0] == 192 && $bits[1] == 168)
6933             || ($bits[0] == 169 && $bits[1] == 254)) {
6934             $lanmatches[] = $match[0];
6935             continue;
6936         }
6937         // finally, it's ok
6938         $goodmatches[] = $match[0];
6939     }
6940     if (!count($goodmatches)) {
6941         // perhaps we have a lan match, it's probably better to return that.
6942         if (!count($lanmatches)) {
6943             return '';
6944         } else {
6945             return array_pop($lanmatches);
6946         }
6947     }
6948     if (count($goodmatches) == 1) {
6949         return $goodmatches[0];
6950     }
6951     error_log("NOTICE: cleanremoteaddr gives us something funny: $originaladdr had ".count($goodmatches)." matches");
6952     // we need to return something, so
6953     return array_pop($goodmatches);
6954 }
6955
6956 /**
6957  * file_put_contents is only supported by php 5.0 and higher
6958  * so if it is not predefined, define it here
6959  *
6960  * @param $file full path of the file to write
6961  * @param $contents contents to be sent
6962  * @return number of bytes written (false on error)
6963  */
6964 if(!function_exists('file_put_contents')) {
6965     function file_put_contents($file, $contents) {
6966         $result = false;
6967         if ($f = fopen($file, 'w')) {
6968             $result = fwrite($f, $contents);
6969             fclose($f);
6970         }
6971         return $result;
6972     }
6973 }
6974
6975 /**
6976  * The clone keyword is only supported from PHP 5 onwards.
6977  * The behaviour of $obj2 = $obj1 differs fundamentally
6978  * between PHP 4 and PHP 5. In PHP 4 a copy of $obj1 was
6979  * created, in PHP 5 $obj1 is referenced. To create a copy
6980  * in PHP 5 the clone keyword was introduced. This function
6981  * simulates this behaviour for PHP < 5.0.0.
6982  * See also: http://mjtsai.com/blog/2004/07/15/php-5-object-references/
6983  *
6984  * Modified 2005-09-29 by Eloy (from Julian Sedding proposal)
6985  * Found a better implementation (more checks and possibilities) from PEAR:
6986  * http://cvs.php.net/co.php/pear/PHP_Compat/Compat/Function/clone.php
6987  *
6988  * @param object $obj
6989  * @return object
6990  */
6991 if(!check_php_version('5.0.0')) {
6992 // the eval is needed to prevent PHP 5 from getting a parse error!
6993 eval('
6994     function clone($obj) {
6995     /// Sanity check
6996         if (!is_object($obj)) {
6997             user_error(\'clone() __clone method called on non-object\', E_USER_WARNING);
6998             return;
6999         }
7000
7001     /// Use serialize/unserialize trick to deep copy the object
7002         $obj = unserialize(serialize($obj));
7003
7004     /// If there is a __clone method call it on the "new" class
7005         if (method_exists($obj, \'__clone\')) {
7006             $obj->__clone();
7007         }
7008
7009         return $obj;
7010     }
7011
7012     // Supply the PHP5 function scandir() to older versions.
7013     function scandir($directory) {
7014         $files = array();
7015         if ($dh = opendir($directory)) {
7016             while (($file = readdir($dh)) !== false) {
7017                $files[] = $file;
7018             }
7019             closedir($dh);
7020         }
7021         return $files;
7022     }
7023
7024     // Supply the PHP5 function array_combine() to older versions.
7025     function array_combine($keys, $values) {
7026         if (!is_array($keys) || !is_array($values) || count($keys) != count($values)) {
7027             return false;
7028         }
7029         reset($values);
7030         $result = array();
7031         foreach ($keys as $key) {
7032             $result[$key] = current($values);
7033             next($values);
7034         }
7035         return $result;
7036     }
7037 ');
7038 }
7039
7040 /**
7041  * This function will make a complete copy of anything it's given,
7042  * regardless of whether it's an object or not.
7043  * @param mixed $thing
7044  * @return mixed
7045  */
7046 function fullclone($thing) {
7047     return unserialize(serialize($thing));
7048 }
7049
7050
7051 /*
7052  * This function expects to called during shutdown
7053  * should be set via register_shutdown_function()
7054  * in lib/setup.php .
7055  *
7056  * Right now we do it only if we are under apache, to
7057  * make sure apache children that hog too much mem are
7058  * killed.
7059  *
7060  */
7061 function moodle_request_shutdown() {
7062
7063     global $CFG;
7064
7065     // initially, we are only ever called under apache
7066     // but check just in case
7067     if (function_exists('apache_child_terminate')
7068         && function_exists('memory_get_usage')
7069         && ini_get_bool('child_terminate')) {
7070         if (empty($CFG->apachemaxmem)) {
7071             $CFG->apachemaxmem = 25000000; // default 25MiB
7072         }
7073         if (memory_get_usage() > (int)$CFG->apachemaxmem) {
7074             trigger_error('Mem usage over $CFG->apachemaxmem: marking child for reaping.');
7075             @apache_child_terminate();
7076         }
7077     }
7078     if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
7079         if (defined('MDL_PERFTOLOG')) {
7080             $perf = get_performance_info();
7081             error_log("PERF: " . $perf['txt']);
7082         }
7083         if (defined('MDL_PERFINC')) {
7084             $inc = get_included_files();
7085             $ts  = 0;
7086             foreach($inc as $f) {
7087                 if (preg_match(':^/:', $f)) {
7088                     $fs  =  filesize($f);
7089                     $ts  += $fs;
7090                     $hfs =  display_size($fs);
7091                     error_log(substr($f,strlen($CFG->dirroot)) . " size: $fs ($hfs)"
7092                               , NULL, NULL, 0);
7093                 } else {
7094                     error_log($f , NULL, NULL, 0);
7095                 }
7096             }
7097             if ($ts > 0 ) {
7098                 $hts = display_size($ts);
7099                 error_log("Total size of files included: $ts ($hts)");
7100             }
7101         }
7102     }
7103 }
7104
7105 /**
7106  * If new messages are waiting for the current user, then return
7107  * Javascript code to create a popup window
7108  *
7109  * @return string Javascript code
7110  */
7111 function message_popup_window() {
7112     global $USER;
7113
7114     $popuplimit = 30;     // Minimum seconds between popups
7115
7116     if (!defined('MESSAGE_WINDOW')) {
7117         if (isset($USER->id) and !isguestuser()) {
7118             if (!isset($USER->message_lastpopup)) {
7119                 $USER->message_lastpopup = 0;
7120             }
7121             if ((time() - $USER->message_lastpopup) > $popuplimit) {  /// It's been long enough
7122                 if (get_user_preferences('message_showmessagewindow', 1) == 1) {
7123                     if (count_records_select('message', 'useridto = \''.$USER->id.'\' AND timecreated > \''.$USER->message_lastpopup.'\'')) {
7124                         $USER->message_lastpopup = time();
7125                         return '<script type="text/javascript">'."\n//<![CDATA[\n openpopup('/message/index.php', 'message',
7126                         'menubar=0,location=0,scrollbars,status,resizable,width=400,height=500', 0);\n//]]>\n</script>";
7127                     }
7128                 }
7129             }
7130         }
7131     }
7132
7133     return '';
7134 }
7135
7136 // Used to make sure that $min <= $value <= $max
7137 function bounded_number($min, $value, $max) {
7138     if($value < $min) {
7139         return $min;
7140     }
7141     if($value > $max) {
7142         return $max;
7143     }
7144     return $value;
7145 }
7146
7147 function array_is_nested($array) {
7148     foreach ($array as $value) {
7149         if (is_array($value)) {
7150             return true;
7151         }
7152     }
7153     return false;
7154 }
7155
7156 /**
7157  *** get_performance_info() pairs up with init_performance_info()
7158  *** loaded in setup.php. Returns an array with 'html' and 'txt'
7159  *** values ready for use, and each of the individual stats provided
7160  *** separately as well.
7161  ***
7162  **/
7163 function get_performance_info() {
7164     global $CFG, $PERF, $rcache;
7165
7166     $info = array();
7167     $info['html'] = '';         // holds userfriendly HTML representation
7168     $info['txt']  = me() . ' '; // holds log-friendly representation
7169
7170     $info['realtime'] = microtime_diff($PERF->starttime, microtime());
7171
7172     $info['html'] .= '<span class="timeused">'.$info['realtime'].' secs</span> ';
7173     $info['txt'] .= 'time: '.$info['realtime'].'s ';
7174
7175     if (function_exists('memory_get_usage')) {
7176         $info['memory_total'] = memory_get_usage();
7177         $info['memory_growth'] = memory_get_usage() - $PERF->startmemory;
7178         $info['html'] .= '<span class="memoryused">RAM: '.display_size($info['memory_total']).'</span> ';
7179         $info['txt']  .= 'memory_total: '.$info['memory_total'].'B (' . display_size($info['memory_total']).') memory_growth: '.$info['memory_growth'].'B ('.display_size($info['memory_growth']).') ';
7180     }
7181
7182     $inc = get_included_files();
7183     //error_log(print_r($inc,1));
7184     $info['includecount'] = count($inc);
7185     $info['html'] .= '<span class="included">Included '.$info['includecount'].' files</span> ';
7186     $info['txt']  .= 'includecount: '.$info['includecount'].' ';
7187
7188     if (!empty($PERF->dbqueries)) {
7189         $info['dbqueries'] = $PERF->dbqueries;
7190         $info['html'] .= '<span class="dbqueries">DB queries '.$info['dbqueries'].'</span> ';
7191         $info['txt'] .= 'dbqueries: '.$info['dbqueries'].' ';
7192     }
7193
7194     if (!empty($PERF->logwrites)) {
7195         $info['logwrites'] = $PERF->logwrites;
7196         $info['html'] .= '<span class="logwrites">Log writes '.$info['logwrites'].'</span> ';
7197         $info['txt'] .= 'logwrites: '.$info['logwrites'].' ';
7198     }
7199
7200     if (!empty($PERF->profiling) && $PERF->profiling) {
7201         require_once($CFG->dirroot .'/lib/profilerlib.php');
7202         $info['html'] .= '<span class="profilinginfo">'.Profiler::get_profiling(array('-R')).'</span>';
7203     }
7204
7205     if (function_exists('posix_times')) {
7206         $ptimes = posix_times();
7207         if (is_array($ptimes)) {
7208             foreach ($ptimes as $key => $val) {
7209                 $info[$key] = $ptimes[$key] -  $PERF->startposixtimes[$key];
7210             }
7211             $info['html'] .= "<span class=\"posixtimes\">ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime]</span> ";
7212             $info['txt'] .= "ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime] ";
7213         }
7214     }
7215
7216     // Grab the load average for the last minute
7217     // /proc will only work under some linux configurations
7218     // while uptime is there under MacOSX/Darwin and other unices
7219     if (is_readable('/proc/loadavg') && $loadavg = @file('/proc/loadavg')) {
7220         list($server_load) = explode(' ', $loadavg[0]);
7221         unset($loadavg);
7222     } else if ( function_exists('is_executable') && is_executable('/usr/bin/uptime') && $loadavg = `/usr/bin/uptime` ) {
7223         if (preg_match('/load averages?: (\d+[\.,:]\d+)/', $loadavg, $matches)) {
7224             $server_load = $matches[1];
7225         } else {
7226             trigger_error('Could not parse uptime output!');
7227         }
7228     }
7229     if (!empty($server_load)) {
7230         $info['serverload'] = $server_load;
7231         $info['html'] .= '<span class="serverload">Load average: '.$info['serverload'].'</span> ';
7232         $info['txt'] .= "serverload: {$info['serverload']} ";
7233     }
7234
7235     if (isset($rcache->hits) && isset($rcache->misses)) {
7236         $info['rcachehits'] = $rcache->hits;
7237         $info['rcachemisses'] = $rcache->misses;
7238         $info['html'] .= '<span class="rcache">Record cache hit/miss ratio : '.
7239             "{$rcache->hits}/{$rcache->misses}</span> ";
7240         $info['txt'] .= 'rcache: '.
7241             "{$rcache->hits}/{$rcache->misses} ";
7242     }
7243     $info['html'] = '<div class="performanceinfo">'.$info['html'].'</div>';
7244     return $info;
7245 }
7246
7247 function apd_get_profiling() {
7248     return shell_exec('pprofp -u ' . ini_get('apd.dumpdir') . '/pprof.' . getmypid() . '.*');
7249 }
7250
7251 function remove_dir($dir, $content_only=false) {
7252     // if content_only=true then delete all but
7253     // the directory itself
7254
7255     $handle = opendir($dir);
7256     while (false!==($item = readdir($handle))) {
7257         if($item != '.' && $item != '..') {
7258             if(is_dir($dir.'/'.$item)) {
7259                 remove_dir($dir.'/'.$item);
7260             }else{
7261                 unlink($dir.'/'.$item);
7262             }
7263         }
7264     }
7265     closedir($handle);
7266     if ($content_only) {
7267         return true;
7268     }
7269     return rmdir($dir);
7270 }
7271
7272 /**
7273  * Function to check if a directory exists and optionally create it.
7274  *
7275  * @param string absolute directory path
7276  * @param boolean create directory if does not exist
7277  * @param boolean create directory recursively
7278  *
7279  * @return boolean true if directory exists or created
7280  */
7281 function check_dir_exists($dir, $create=false, $recursive=false) {
7282
7283     global $CFG;
7284
7285     $status = true;
7286
7287     if(!is_dir($dir)) {
7288         if (!$create) {
7289             $status = false;
7290         } else {
7291             umask(0000);
7292             if ($recursive) {
7293                 // PHP 5.0 has recursive mkdir parameter, but 4.x does not :-(
7294                 $dir = str_replace('\\', '/', $dir); //windows compatibility
7295                 $dirs = explode('/', $dir);
7296                 $dir = array_shift($dirs).'/'; //skip root or drive letter
7297                 foreach ($dirs as $part) {
7298                     if ($part == '') {
7299                         continue;
7300                     }
7301                     $dir .= $part.'/';
7302                     if (!is_dir($dir)) {
7303                         if (!mkdir($dir, $CFG->directorypermissions)) {
7304                             $status = false;
7305                             break;
7306                         }
7307                     }
7308                 }
7309             } else {
7310                 $status = mkdir($dir, $CFG->directorypermissions);
7311             }
7312         }
7313     }
7314     return $status;
7315 }
7316
7317 function report_session_error() {
7318     global $CFG, $FULLME;
7319
7320     if (empty($CFG->lang)) {
7321         $CFG->lang = "en";
7322     }
7323     // Set up default theme and locale
7324     theme_setup();
7325     moodle_setlocale();
7326
7327     //clear session cookies
7328     setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7329     setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7330     //increment database error counters
7331     if (isset($CFG->session_error_counter)) {
7332         set_config('session_error_counter', 1 + $CFG->session_error_counter);
7333     } else {
7334         set_config('session_error_counter', 1);
7335     }
7336     redirect($FULLME, get_string('sessionerroruser2', 'error'), 5);
7337 }
7338
7339
7340 /**
7341  * Detect if an object or a class contains a given property
7342  * will take an actual object or the name of a class
7343  * @param mix $obj Name of class or real object to test
7344  * @param string $property name of property to find
7345  * @return bool true if property exists
7346  */
7347 function object_property_exists( $obj, $property ) {
7348     if (is_string( $obj )) {
7349         $properties = get_class_vars( $obj );
7350     }
7351     else {
7352         $properties = get_object_vars( $obj );
7353     }
7354     return array_key_exists( $property, $properties );
7355 }
7356
7357
7358 /**
7359  * Detect a custom script replacement in the data directory that will
7360  * replace an existing moodle script
7361  * @param string $urlpath path to the original script
7362  * @return string full path name if a custom script exists
7363  * @return bool false if no custom script exists
7364  */
7365 function custom_script_path($urlpath='') {
7366     global $CFG;
7367
7368     // set default $urlpath, if necessary
7369     if (empty($urlpath)) {
7370         $urlpath = qualified_me(); // e.g. http://www.this-server.com/moodle/this-script.php
7371     }
7372
7373     // $urlpath is invalid if it is empty or does not start with the Moodle wwwroot
7374     if (empty($urlpath) or (strpos($urlpath, $CFG->wwwroot) === false )) {
7375         return false;
7376     }
7377
7378     // replace wwwroot with the path to the customscripts folder and clean path
7379     $scriptpath = $CFG->customscripts . clean_param(substr($urlpath, strlen($CFG->wwwroot)), PARAM_PATH);
7380
7381     // remove the query string, if any
7382     if (($strpos = strpos($scriptpath, '?')) !== false) {
7383         $scriptpath = substr($scriptpath, 0, $strpos);
7384     }
7385
7386     // remove trailing slashes, if any
7387     $scriptpath = rtrim($scriptpath, '/\\');
7388
7389     // append index.php, if necessary
7390     if (is_dir($scriptpath)) {
7391         $scriptpath .= '/index.php';
7392     }
7393
7394     // check the custom script exists
7395     if (file_exists($scriptpath)) {
7396         return $scriptpath;
7397     } else {
7398         return false;
7399     }
7400 }
7401
7402 /**
7403  * Wrapper function to load necessary editor scripts
7404  * to $CFG->editorsrc array. Params can be coursei id
7405  * or associative array('courseid' => value, 'name' => 'editorname').
7406  * @uses $CFG
7407  * @param mixed $args Courseid or associative array.
7408  */
7409 function loadeditor($args) {
7410     global $CFG;
7411     include($CFG->libdir .'/editorlib.php');
7412     return editorObject::loadeditor($args);
7413 }
7414
7415 /**
7416  * Returns whether or not the user object is a remote MNET user. This function
7417  * is in moodlelib because it does not rely on loading any of the MNET code.
7418  *
7419  * @param object $user A valid user object
7420  * @return bool        True if the user is from a remote Moodle.
7421  */
7422 function is_mnet_remote_user($user) {
7423     global $CFG;
7424
7425     if (!isset($CFG->mnet_localhost_id)) {
7426         include_once $CFG->dirroot . '/mnet/lib.php';
7427         $env = new mnet_environment();
7428         $env->init();
7429         unset($env);
7430     }
7431
7432     return (!empty($user->mnethostid) && $user->mnethostid != $CFG->mnet_localhost_id);
7433 }
7434
7435 /**
7436  * Checks if a given plugin is in the list of enabled enrolment plugins.
7437  *
7438  * @param string $auth Enrolment plugin.
7439  * @return boolean Whether the plugin is enabled.
7440  */
7441 function is_enabled_enrol($enrol='') {
7442     global $CFG;
7443
7444     // use the global default if not specified
7445     if ($enrol == '') {
7446         $enrol = $CFG->enrol;
7447     }
7448     return in_array($enrol, explode(',', $CFG->enrol_plugins_enabled));
7449 }
7450
7451 /**
7452  * This function will search for browser prefereed languages, setting Moodle
7453  * to use the best one available if $SESSION->lang is undefined
7454  */
7455 function setup_lang_from_browser() {
7456
7457     global $CFG, $SESSION, $USER;
7458
7459     if (!empty($SESSION->lang) or !empty($USER->lang)) {
7460         // Lang is defined in session or user profile, nothing to do
7461         return;
7462     }
7463
7464     if (!isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) { // There isn't list of browser langs, nothing to do
7465         return;
7466     }
7467
7468 /// Extract and clean langs from headers
7469     $rawlangs = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
7470     $rawlangs = str_replace('-', '_', $rawlangs);         // we are using underscores
7471     $rawlangs = explode(',', $rawlangs);                  // Convert to array
7472     $langs = array();
7473
7474     $order = 1.0;
7475     foreach ($rawlangs as $lang) {
7476         if (strpos($lang, ';') === false) {
7477             $langs[(string)$order] = $lang;
7478             $order = $order-0.01;
7479         } else {
7480             $parts = explode(';', $lang);
7481             $pos = strpos($parts[1], '=');
7482             $langs[substr($parts[1], $pos+1)] = $parts[0];
7483         }
7484     }
7485     krsort($langs, SORT_NUMERIC);
7486
7487     $langlist = get_list_of_languages();
7488
7489 /// Look for such langs under standard locations
7490     foreach ($langs as $lang) {
7491         $lang = strtolower(clean_param($lang.'_utf8', PARAM_SAFEDIR)); // clean it properly for include
7492         if (!array_key_exists($lang, $langlist)) {
7493             continue; // language not allowed, try next one
7494         }
7495         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
7496             $SESSION->lang = $lang; /// Lang exists, set it in session
7497             break; /// We have finished. Go out
7498         }
7499     }
7500     return;
7501 }
7502
7503
7504 ////////////////////////////////////////////////////////////////////////////////
7505
7506 function is_newnav($navigation) {
7507     if (is_array($navigation) && !empty($navigation['newnav'])) {
7508         return true;
7509     } else {
7510         return false;
7511     }
7512 }
7513
7514 /**
7515  * Checks whether the given variable name is defined as a variable within the given object.
7516  * @note This will NOT work with stdClass objects, which have no class variables.
7517  * @param string $var The variable name
7518  * @param object $object The object to check
7519  * @return boolean
7520  */
7521 function in_object_vars($var, $object) {
7522     $class_vars = get_class_vars(get_class($object));
7523     $class_vars = array_keys($class_vars);
7524     return in_array($var, $class_vars);
7525 }
7526
7527 /**
7528  * Returns an array without repeated objects.
7529  * This function is similar to array_unique, but for arrays that have objects as values
7530  *
7531  * @param unknown_type $array
7532  * @param unknown_type $keep_key_assoc
7533  * @return unknown
7534  */
7535 function object_array_unique($array, $keep_key_assoc = true) {
7536     $duplicate_keys = array();
7537     $tmp         = array();
7538
7539     foreach ($array as $key=>$val) {
7540         // convert objects to arrays, in_array() does not support objects
7541         if (is_object($val)) {
7542             $val = (array)$val;
7543         }
7544
7545         if (!in_array($val, $tmp)) {
7546             $tmp[] = $val;
7547         } else {
7548             $duplicate_keys[] = $key;
7549         }
7550     }
7551
7552     foreach ($duplicate_keys as $key) {
7553         unset($array[$key]);
7554     }
7555
7556     return $keep_key_assoc ? $array : array_values($array);
7557 }
7558
7559 // vim:autoindent:expandtab:shiftwidth=4:tabstop=4:tw=140:
7560 ?>