lib/moodlelib.php

   1 <?php // $Id$
   2
   3 ///////////////////////////////////////////////////////////////////////////
   4 //                                                                       //
   5 // NOTICE OF COPYRIGHT                                                   //
   6 //                                                                       //
   7 // Moodle - Modular Object-Oriented Dynamic Learning Environment         //
   8 //          http://moodle.org                                            //
   9 //                                                                       //
  10 // Copyright (C) 1999-2004  Martin Dougiamas  http://dougiamas.com       //
  11 //                                                                       //
  12 // This program is free software; you can redistribute it and/or modify  //
  13 // it under the terms of the GNU General Public License as published by  //
  14 // the Free Software Foundation; either version 2 of the License, or     //
  15 // (at your option) any later version.                                   //
  16 //                                                                       //
  17 // This program is distributed in the hope that it will be useful,       //
  18 // but WITHOUT ANY WARRANTY; without even the implied warranty of        //
  19 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         //
  20 // GNU General Public License for more details:                          //
  21 //                                                                       //
  22 //          http://www.gnu.org/copyleft/gpl.html                         //
  23 //                                                                       //
  24 ///////////////////////////////////////////////////////////////////////////
  25
  26 /**
  27  * moodlelib.php - Moodle main library
  28  *
  29  * Main library file of miscellaneous general-purpose Moodle functions.
  30  * Other main libraries:
  31  *  - weblib.php      - functions that produce web output
  32  *  - datalib.php     - functions that access the database
  33  * @author Martin Dougiamas
  34  * @version $Id$
  35  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  36  * @package moodlecore
  37  */
  38
  39 /// CONSTANTS (Encased in phpdoc proper comments)/////////////////////////
  40
  41 /**
  42  * Used by some scripts to check they are being called by Moodle
  43  */
  44 define('MOODLE_INTERNAL', true);
  45
  46 /**
  47  * No groups used?
  48  */
  49 define('NOGROUPS', 0);
  50
  51 /**
  52  * Groups used?
  53  */
  54 define('SEPARATEGROUPS', 1);
  55
  56 /**
  57  * Groups visible?
  58  */
  59 define('VISIBLEGROUPS', 2);
  60
  61 /// Date and time constants ///
  62 /**
  63  * Time constant - the number of seconds in a year
  64  */
  65
  66 define('YEARSECS', 31536000);
  67
  68 /**
  69  * Time constant - the number of seconds in a week
  70  */
  71 define('WEEKSECS', 604800);
  72
  73 /**
  74  * Time constant - the number of seconds in a day
  75  */
  76 define('DAYSECS', 86400);
  77
  78 /**
  79  * Time constant - the number of seconds in an hour
  80  */
  81 define('HOURSECS', 3600);
  82
  83 /**
  84  * Time constant - the number of seconds in a minute
  85  */
  86 define('MINSECS', 60);
  87
  88 /**
  89  * Time constant - the number of minutes in a day
  90  */
  91 define('DAYMINS', 1440);
  92
  93 /**
  94  * Time constant - the number of minutes in an hour
  95  */
  96 define('HOURMINS', 60);
  97
  98 /// Parameter constants - every call to optional_param(), required_param()  ///
  99 /// or clean_param() should have a specified type of parameter.  //////////////
 100
 101 /**
 102  * PARAM_RAW specifies a parameter that is not cleaned/processed in any way;
 103  * originally was 0, but changed because we need to detect unknown
 104  * parameter types and swiched order in clean_param().
 105  */
 106 define('PARAM_RAW', 666);
 107
 108 /**
 109  * PARAM_CLEAN - obsoleted, please try to use more specific type of parameter.
 110  * It was one of the first types, that is why it is abused so much ;-)
 111  */
 112 define('PARAM_CLEAN',    0x0001);
 113
 114 /**
 115  * PARAM_INT - integers only, use when expecting only numbers.
 116  */
 117 define('PARAM_INT',      0x0002);
 118
 119 /**
 120  * PARAM_INTEGER - an alias for PARAM_INT
 121  */
 122 define('PARAM_INTEGER',  0x0002);
 123
 124 /**
 125  * PARAM_NUMBER - a real/floating point number.
 126  */
 127 define('PARAM_NUMBER',  0x000a);
 128
 129 /**
 130  * PARAM_ALPHA - contains only english letters.
 131  */
 132 define('PARAM_ALPHA',    0x0004);
 133
 134 /**
 135  * PARAM_ACTION - an alias for PARAM_ALPHA, use for various actions in formas and urls
 136  * @TODO: should we alias it to PARAM_ALPHANUM ?
 137  */
 138 define('PARAM_ACTION',   0x0004);
 139
 140 /**
 141  * PARAM_FORMAT - an alias for PARAM_ALPHA, use for names of plugins, formats, etc.
 142  * @TODO: should we alias it to PARAM_ALPHANUM ?
 143  */
 144 define('PARAM_FORMAT',   0x0004);
 145
 146 /**
 147  * PARAM_NOTAGS - all html tags are stripped from the text. Do not abuse this type.
 148  */
 149 define('PARAM_NOTAGS',   0x0008);
 150
 151  /**
 152  * PARAM_MULTILANG - alias of PARAM_TEXT.
 153  */
 154 define('PARAM_MULTILANG',  0x0009);
 155
 156  /**
 157  * PARAM_TEXT - general plain text compatible with multilang filter, no other html tags.
 158  */
 159 define('PARAM_TEXT',  0x0009);
 160
 161 /**
 162  * PARAM_FILE - safe file name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 163  */
 164 define('PARAM_FILE',     0x0010);
 165
 166 /**
 167  * PARAM_PATH - safe relative path name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 168  * note: the leading slash is not removed, window drive letter is not allowed
 169  */
 170 define('PARAM_PATH',     0x0020);
 171
 172 /**
 173  * PARAM_HOST - expected fully qualified domain name (FQDN) or an IPv4 dotted quad (IP address)
 174  */
 175 define('PARAM_HOST',     0x0040);
 176
 177 /**
 178  * PARAM_URL - expected properly formatted URL.
 179  */
 180 define('PARAM_URL',      0x0080);
 181
 182 /**
 183  * 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!)
 184  */
 185 define('PARAM_LOCALURL', 0x0180);
 186
 187 /**
 188  * PARAM_CLEANFILE - safe file name, all dangerous and regional chars are removed,
 189  * use when you want to store a new file submitted by students
 190  */
 191 define('PARAM_CLEANFILE',0x0200);
 192
 193 /**
 194  * PARAM_ALPHANUM - expected numbers and letters only.
 195  */
 196 define('PARAM_ALPHANUM', 0x0400);
 197
 198 /**
 199  * PARAM_BOOL - converts input into 0 or 1, use for switches in forms and urls.
 200  */
 201 define('PARAM_BOOL',     0x0800);
 202
 203 /**
 204  * PARAM_CLEANHTML - cleans submitted HTML code and removes slashes
 205  * note: do not forget to addslashes() before storing into database!
 206  */
 207 define('PARAM_CLEANHTML',0x1000);
 208
 209 /**
 210  * PARAM_ALPHAEXT the same contents as PARAM_ALPHA plus the chars in quotes: "/-_" allowed,
 211  * suitable for include() and require()
 212  * @TODO: should we rename this function to PARAM_SAFEDIRS??
 213  */
 214 define('PARAM_ALPHAEXT', 0x2000);
 215
 216 /**
 217  * PARAM_SAFEDIR - safe directory name, suitable for include() and require()
 218  */
 219 define('PARAM_SAFEDIR',  0x4000);
 220
 221 /**
 222  * PARAM_SEQUENCE - expects a sequence of numbers like 8 to 1,5,6,4,6,8,9.  Numbers and comma only.
 223  */
 224 define('PARAM_SEQUENCE',  0x8000);
 225
 226 /**
 227  * PARAM_PEM - Privacy Enhanced Mail format
 228  */
 229 define('PARAM_PEM',      0x10000);
 230
 231 /**
 232  * PARAM_BASE64 - Base 64 encoded format
 233  */
 234 define('PARAM_BASE64',   0x20000);
 235
 236
 237 /// Page types ///
 238 /**
 239  * PAGE_COURSE_VIEW is a definition of a page type. For more information on the page class see moodle/lib/pagelib.php.
 240  */
 241 define('PAGE_COURSE_VIEW', 'course-view');
 242
 243 /// Debug levels ///
 244 /** no warnings at all */
 245 define ('DEBUG_NONE', 0);
 246 /** E_ERROR | E_PARSE */
 247 define ('DEBUG_MINIMAL', 5);
 248 /** E_ERROR | E_PARSE | E_WARNING | E_NOTICE */
 249 define ('DEBUG_NORMAL', 15);
 250 /** E_ALL without E_STRICT and E_RECOVERABLE_ERROR for now */
 251 define ('DEBUG_ALL', 2047);
 252 /** DEBUG_ALL with extra Moodle debug messages - (DEBUG_ALL | 32768) */
 253 define ('DEBUG_DEVELOPER', 34815);
 254
 255 /**
 256  * Blog access level constant declaration
 257  */
 258 define ('BLOG_USER_LEVEL', 1);
 259 define ('BLOG_GROUP_LEVEL', 2);
 260 define ('BLOG_COURSE_LEVEL', 3);
 261 define ('BLOG_SITE_LEVEL', 4);
 262 define ('BLOG_GLOBAL_LEVEL', 5);
 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         case PARAM_PEM:
 504             $param = trim($param);
 505             // PEM formatted strings may contain letters/numbers and the symbols
 506             // forward slash: /
 507             // plus sign:     +
 508             // equal sign:    =
 509             // , surrounded by BEGIN and END CERTIFICATE prefix and suffixes
 510             if (preg_match('/^-----BEGIN CERTIFICATE-----([\s\w\/\+=]+)-----END CERTIFICATE-----$/', trim($param), $matches)) {
 511                 list($wholething, $body) = $matches;
 512                 unset($wholething, $matches);
 513                 $b64 = clean_param($body, PARAM_BASE64);
 514                 if (!empty($b64)) {
 515                     return "-----BEGIN CERTIFICATE-----\n$b64\n-----END CERTIFICATE-----\n";
 516                 } else {
 517                     return '';
 518                 }
 519             }
 520             return '';
 521         case PARAM_BASE64:
 522             if (!empty($param)) {
 523                 // PEM formatted strings may contain letters/numbers and the symbols
 524                 // forward slash: /
 525                 // plus sign:     +
 526                 // equal sign:    =
 527                 if (0 >= preg_match('/^([\s\w\/\+=]+)$/', trim($param))) {
 528                     return '';
 529                 }
 530                 $lines = preg_split('/[\s]+/', $param, -1, PREG_SPLIT_NO_EMPTY);
 531                 // Each line of base64 encoded data must be 64 characters in
 532                 // length, except for the last line which may be less than (or
 533                 // equal to) 64 characters long.
 534                 for ($i=0, $j=count($lines); $i < $j; $i++) {
 535                     if ($i + 1 == $j) {
 536                         if (64 < strlen($lines[$i])) {
 537                             return '';
 538                         }
 539                         continue;
 540                     }
 541
 542                     if (64 != strlen($lines[$i])) {
 543                         return '';
 544                     }
 545                 }
 546                 return implode("\n",$lines);
 547             } else {
 548                 return '';
 549             }
 550         default:                 // throw error, switched parameters in optional_param or another serious problem
 551             error("Unknown parameter type: $type");
 552     }
 553 }
 554
 555
 556
 557 /**
 558  * Set a key in global configuration
 559  *
 560  * Set a key/value pair in both this session's {@link $CFG} global variable
 561  * and in the 'config' database table for future sessions.
 562  *
 563  * Can also be used to update keys for plugin-scoped configs in config_plugin table.
 564  * In that case it doesn't affect $CFG.
 565  *
 566  * @param string $name the key to set
 567  * @param string $value the value to set (without magic quotes)
 568  * @param string $plugin (optional) the plugin scope
 569  * @uses $CFG
 570  * @return bool
 571  */
 572 function set_config($name, $value, $plugin=NULL) {
 573 /// No need for get_config because they are usually always available in $CFG
 574
 575     global $CFG;
 576
 577     if (empty($plugin)) {
 578         $CFG->$name = $value;  // So it's defined for this invocation at least
 579
 580         if (get_field('config', 'name', 'name', $name)) {
 581             return set_field('config', 'value', addslashes($value), 'name', $name);
 582         } else {
 583             $config = new object();
 584             $config->name = $name;
 585             $config->value = addslashes($value);
 586             return insert_record('config', $config);
 587         }
 588     } else { // plugin scope
 589         if ($id = get_field('config_plugins', 'id', 'name', $name, 'plugin', $plugin)) {
 590             return set_field('config_plugins', 'value', addslashes($value), 'id', $id);
 591         } else {
 592             $config = new object();
 593             $config->plugin = addslashes($plugin);
 594             $config->name   = $name;
 595             $config->value  = addslashes($value);
 596             return insert_record('config_plugins', $config);
 597         }
 598     }
 599 }
 600
 601 /**
 602  * Get configuration values from the global config table
 603  * or the config_plugins table.
 604  *
 605  * If called with no parameters it will do the right thing
 606  * generating $CFG safely from the database without overwriting
 607  * existing values.
 608  *
 609  * If called with 2 parameters it will return a $string single
 610  * value or false of the value is not found.
 611  *
 612  * @param string $plugin
 613  * @param string $name
 614  * @uses $CFG
 615  * @return hash-like object or single value
 616  *
 617  */
 618 function get_config($plugin=NULL, $name=NULL) {
 619
 620     global $CFG;
 621
 622     if (!empty($name)) { // the user is asking for a specific value
 623         if (!empty($plugin)) {
 624             return get_field('config_plugins', 'value', 'plugin' , $plugin, 'name', $name);
 625         } else {
 626             return get_field('config', 'value', 'name', $name);
 627         }
 628     }
 629
 630     // the user is after a recordset
 631     if (!empty($plugin)) {
 632         if ($configs=get_records('config_plugins', 'plugin', $plugin, '', 'name,value')) {
 633             $configs = (array)$configs;
 634             $localcfg = array();
 635             foreach ($configs as $config) {
 636                 $localcfg[$config->name] = $config->value;
 637             }
 638             return (object)$localcfg;
 639         } else {
 640             return false;
 641         }
 642     } else {
 643         // this was originally in setup.php
 644         if ($configs = get_records('config')) {
 645             $localcfg = (array)$CFG;
 646             foreach ($configs as $config) {
 647                 if (!isset($localcfg[$config->name])) {
 648                     $localcfg[$config->name] = $config->value;
 649                 } else {
 650                     if ($localcfg[$config->name] != $config->value ) {
 651                         // complain if the DB has a different
 652                         // value than config.php does
 653                         error_log("\$CFG->{$config->name} in config.php ({$localcfg[$config->name]}) overrides database setting ({$config->value})");
 654                     }
 655                 }
 656             }
 657
 658             $localcfg = (object)$localcfg;
 659             return $localcfg;
 660         } else {
 661             // preserve $CFG if DB returns nothing or error
 662             return $CFG;
 663         }
 664
 665     }
 666 }
 667
 668 /**
 669  * Removes a key from global configuration
 670  *
 671  * @param string $name the key to set
 672  * @param string $plugin (optional) the plugin scope
 673  * @uses $CFG
 674  * @return bool
 675  */
 676 function unset_config($name, $plugin=NULL) {
 677
 678     global $CFG;
 679
 680     unset($CFG->$name);
 681
 682     if (empty($plugin)) {
 683         return delete_records('config', 'name', $name);
 684     } else {
 685         return delete_records('config_plugins', 'name', $name, 'plugin', $plugin);
 686     }
 687 }
 688
 689
 690 /**
 691  * Refresh current $USER session global variable with all their current preferences.
 692  * @uses $USER
 693  */
 694 function reload_user_preferences() {
 695
 696     global $USER;
 697
 698     //reset preference
 699     $USER->preference = array();
 700
 701     if (!isloggedin() or isguestuser()) {
 702         // no pernament storage for not-logged-in user and guest
 703
 704     } else if ($preferences = get_records('user_preferences', 'userid', $USER->id)) {
 705         foreach ($preferences as $preference) {
 706             $USER->preference[$preference->name] = $preference->value;
 707         }
 708     }
 709
 710     return true;
 711 }
 712
 713 /**
 714  * Sets a preference for the current user
 715  * Optionally, can set a preference for a different user object
 716  * @uses $USER
 717  * @todo Add a better description and include usage examples. Add inline links to $USER and user functions in above line.
 718
 719  * @param string $name The key to set as preference for the specified user
 720  * @param string $value The value to set forthe $name key in the specified user's record
 721  * @param int $otheruserid A moodle user ID
 722  * @return bool
 723  */
 724 function set_user_preference($name, $value, $otheruserid=NULL) {
 725
 726     global $USER;
 727
 728     if (!isset($USER->preference)) {
 729         reload_user_preferences();
 730     }
 731
 732     if (empty($name)) {
 733         return false;
 734     }
 735
 736     $nostore = false;
 737
 738     if (empty($otheruserid)){
 739         if (!isloggedin() or isguestuser()) {
 740             $nostore = true;
 741         }
 742         $userid = $USER->id;
 743     } else {
 744         if (isguestuser($otheruserid)) {
 745             $nostore = true;
 746         }
 747         $userid = $otheruserid;
 748     }
 749
 750     $return = true;
 751     if ($nostore) {
 752         // no pernament storage for not-logged-in user and guest
 753
 754     } else if ($preference = get_record('user_preferences', 'userid', $userid, 'name', addslashes($name))) {
 755         if (!set_field('user_preferences', 'value', addslashes((string)$value), 'id', $preference->id)) {
 756             $return = false;
 757         }
 758
 759     } else {
 760         $preference = new object();
 761         $preference->userid = $userid;
 762         $preference->name   = addslashes($name);
 763         $preference->value  = addslashes((string)$value);
 764         if (!insert_record('user_preferences', $preference)) {
 765             $return = false;
 766         }
 767     }
 768
 769     // update value in USER session if needed
 770     if ($userid == $USER->id) {
 771         $USER->preference[$name] = (string)$value;
 772     }
 773
 774     return $return;
 775 }
 776
 777 /**
 778  * Unsets a preference completely by deleting it from the database
 779  * Optionally, can set a preference for a different user id
 780  * @uses $USER
 781  * @param string  $name The key to unset as preference for the specified user
 782  * @param int $otheruserid A moodle user ID
 783  */
 784 function unset_user_preference($name, $otheruserid=NULL) {
 785
 786     global $USER;
 787
 788     if (!isset($USER->preference)) {
 789         reload_user_preferences();
 790     }
 791
 792     if (empty($otheruserid)){
 793         $userid = $USER->id;
 794     } else {
 795         $userid = $otheruserid;
 796     }
 797
 798     //Delete the preference from $USER if needed
 799     if ($userid == $USER->id) {
 800         unset($USER->preference[$name]);
 801     }
 802
 803     //Then from DB
 804     return delete_records('user_preferences', 'userid', $userid, 'name', addslashes($name));
 805 }
 806
 807
 808 /**
 809  * Sets a whole array of preferences for the current user
 810  * @param array $prefarray An array of key/value pairs to be set
 811  * @param int $otheruserid A moodle user ID
 812  * @return bool
 813  */
 814 function set_user_preferences($prefarray, $otheruserid=NULL) {
 815
 816     if (!is_array($prefarray) or empty($prefarray)) {
 817         return false;
 818     }
 819
 820     $return = true;
 821     foreach ($prefarray as $name => $value) {
 822         // The order is important; test for return is done first
 823         $return = (set_user_preference($name, $value, $otheruserid) && $return);
 824     }
 825     return $return;
 826 }
 827
 828 /**
 829  * If no arguments are supplied this function will return
 830  * all of the current user preferences as an array.
 831  * If a name is specified then this function
 832  * attempts to return that particular preference value.  If
 833  * none is found, then the optional value $default is returned,
 834  * otherwise NULL.
 835  * @param string $name Name of the key to use in finding a preference value
 836  * @param string $default Value to be returned if the $name key is not set in the user preferences
 837  * @param int $otheruserid A moodle user ID
 838  * @uses $USER
 839  * @return string
 840  */
 841 function get_user_preferences($name=NULL, $default=NULL, $otheruserid=NULL) {
 842     global $USER;
 843
 844     if (!isset($USER->preference)) {
 845         reload_user_preferences();
 846     }
 847
 848     if (empty($otheruserid)){
 849         $userid = $USER->id;
 850     } else {
 851         $userid = $otheruserid;
 852     }
 853
 854     if ($userid == $USER->id) {
 855         $preference = $USER->preference;
 856
 857     } else {
 858         $preference = array();
 859         if ($prefdata = get_records('user_preferences', 'userid', $userid)) {
 860             foreach ($prefdata as $pref) {
 861                 $preference[$pref->name] = $pref->value;
 862             }
 863         }
 864     }
 865
 866     if (empty($name)) {
 867         return $preference;            // All values
 868
 869     } else if (array_key_exists($name, $preference)) {
 870         return $preference[$name];    // The single value
 871
 872     } else {
 873         return $default;              // Default value (or NULL)
 874     }
 875 }
 876
 877
 878 /// FUNCTIONS FOR HANDLING TIME ////////////////////////////////////////////
 879
 880 /**
 881  * Given date parts in user time produce a GMT timestamp.
 882  *
 883  * @param int $year The year part to create timestamp of
 884  * @param int $month The month part to create timestamp of
 885  * @param int $day The day part to create timestamp of
 886  * @param int $hour The hour part to create timestamp of
 887  * @param int $minute The minute part to create timestamp of
 888  * @param int $second The second part to create timestamp of
 889  * @param float $timezone ?
 890  * @param bool $applydst ?
 891  * @return int timestamp
 892  * @todo Finish documenting this function
 893  */
 894 function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0, $timezone=99, $applydst=true) {
 895
 896     $timezone = get_user_timezone_offset($timezone);
 897
 898     if (abs($timezone) > 13) {
 899         $time = mktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 900     } else {
 901         $time = gmmktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 902         $time = usertime($time, $timezone);
 903         if($applydst) {
 904             $time -= dst_offset_on($time);
 905         }
 906     }
 907
 908     return $time;
 909
 910 }
 911
 912 /**
 913  * Given an amount of time in seconds, returns string
 914  * formatted nicely as weeks, days, hours etc as needed
 915  *
 916  * @uses MINSECS
 917  * @uses HOURSECS
 918  * @uses DAYSECS
 919  * @uses YEARSECS
 920  * @param int $totalsecs ?
 921  * @param array $str ?
 922  * @return string
 923  */
 924  function format_time($totalsecs, $str=NULL) {
 925
 926     $totalsecs = abs($totalsecs);
 927
 928     if (!$str) {  // Create the str structure the slow way
 929         $str->day   = get_string('day');
 930         $str->days  = get_string('days');
 931         $str->hour  = get_string('hour');
 932         $str->hours = get_string('hours');
 933         $str->min   = get_string('min');
 934         $str->mins  = get_string('mins');
 935         $str->sec   = get_string('sec');
 936         $str->secs  = get_string('secs');
 937         $str->year  = get_string('year');
 938         $str->years = get_string('years');
 939     }
 940
 941
 942     $years     = floor($totalsecs/YEARSECS);
 943     $remainder = $totalsecs - ($years*YEARSECS);
 944     $days      = floor($remainder/DAYSECS);
 945     $remainder = $totalsecs - ($days*DAYSECS);
 946     $hours     = floor($remainder/HOURSECS);
 947     $remainder = $remainder - ($hours*HOURSECS);
 948     $mins      = floor($remainder/MINSECS);
 949     $secs      = $remainder - ($mins*MINSECS);
 950
 951     $ss = ($secs == 1)  ? $str->sec  : $str->secs;
 952     $sm = ($mins == 1)  ? $str->min  : $str->mins;
 953     $sh = ($hours == 1) ? $str->hour : $str->hours;
 954     $sd = ($days == 1)  ? $str->day  : $str->days;
 955     $sy = ($years == 1)  ? $str->year  : $str->years;
 956
 957     $oyears = '';
 958     $odays = '';
 959     $ohours = '';
 960     $omins = '';
 961     $osecs = '';
 962
 963     if ($years)  $oyears  = $years .' '. $sy;
 964     if ($days)  $odays  = $days .' '. $sd;
 965     if ($hours) $ohours = $hours .' '. $sh;
 966     if ($mins)  $omins  = $mins .' '. $sm;
 967     if ($secs)  $osecs  = $secs .' '. $ss;
 968
 969     if ($years) return trim($oyears .' '. $odays);
 970     if ($days)  return trim($odays .' '. $ohours);
 971     if ($hours) return trim($ohours .' '. $omins);
 972     if ($mins)  return trim($omins .' '. $osecs);
 973     if ($secs)  return $osecs;
 974     return get_string('now');
 975 }
 976
 977 /**
 978  * Returns a formatted string that represents a date in user time
 979  * <b>WARNING: note that the format is for strftime(), not date().</b>
 980  * Because of a bug in most Windows time libraries, we can't use
 981  * the nicer %e, so we have to use %d which has leading zeroes.
 982  * A lot of the fuss in the function is just getting rid of these leading
 983  * zeroes as efficiently as possible.
 984  *
 985  * If parameter fixday = true (default), then take off leading
 986  * zero from %d, else mantain it.
 987  *
 988  * @uses HOURSECS
 989  * @param  int $date timestamp in GMT
 990  * @param string $format strftime format
 991  * @param float $timezone
 992  * @param bool $fixday If true (default) then the leading
 993  * zero from %d is removed. If false then the leading zero is mantained.
 994  * @return string
 995  */
 996 function userdate($date, $format='', $timezone=99, $fixday = true) {
 997
 998     global $CFG;
 999
1000     if (empty($format)) {
1001         $format = get_string('strftimedaydatetime');
1002     }
1003
1004     if (!empty($CFG->nofixday)) {  // Config.php can force %d not to be fixed.
1005         $fixday = false;
1006     } else if ($fixday) {
1007         $formatnoday = str_replace('%d', 'DD', $format);
1008         $fixday = ($formatnoday != $format);
1009     }
1010
1011     $date += dst_offset_on($date);
1012
1013     $timezone = get_user_timezone_offset($timezone);
1014
1015     if (abs($timezone) > 13) {   /// Server time
1016         if ($fixday) {
1017             $datestring = strftime($formatnoday, $date);
1018             $daystring  = str_replace(' 0', '', strftime(' %d', $date));
1019             $datestring = str_replace('DD', $daystring, $datestring);
1020         } else {
1021             $datestring = strftime($format, $date);
1022         }
1023     } else {
1024         $date += (int)($timezone * 3600);
1025         if ($fixday) {
1026             $datestring = gmstrftime($formatnoday, $date);
1027             $daystring  = str_replace(' 0', '', gmstrftime(' %d', $date));
1028             $datestring = str_replace('DD', $daystring, $datestring);
1029         } else {
1030             $datestring = gmstrftime($format, $date);
1031         }
1032     }
1033
1034 /// If we are running under Windows convert from windows encoding to UTF-8
1035 /// (because it's impossible to specify UTF-8 to fetch locale info in Win32)
1036
1037    if ($CFG->ostype == 'WINDOWS') {
1038        if ($localewincharset = get_string('localewincharset')) {
1039            $textlib = textlib_get_instance();
1040            $datestring = $textlib->convert($datestring, $localewincharset, 'utf-8');
1041        }
1042    }
1043
1044     return $datestring;
1045 }
1046
1047 /**
1048  * Given a $time timestamp in GMT (seconds since epoch),
1049  * returns an array that represents the date in user time
1050  *
1051  * @uses HOURSECS
1052  * @param int $time Timestamp in GMT
1053  * @param float $timezone ?
1054  * @return array An array that represents the date in user time
1055  * @todo Finish documenting this function
1056  */
1057 function usergetdate($time, $timezone=99) {
1058
1059     $timezone = get_user_timezone_offset($timezone);
1060
1061     if (abs($timezone) > 13) {    // Server time
1062         return getdate($time);
1063     }
1064
1065     // There is no gmgetdate so we use gmdate instead
1066     $time += dst_offset_on($time);
1067     $time += intval((float)$timezone * HOURSECS);
1068
1069     $datestring = gmstrftime('%S_%M_%H_%d_%m_%Y_%w_%j_%A_%B', $time);
1070
1071     list(
1072         $getdate['seconds'],
1073         $getdate['minutes'],
1074         $getdate['hours'],
1075         $getdate['mday'],
1076         $getdate['mon'],
1077         $getdate['year'],
1078         $getdate['wday'],
1079         $getdate['yday'],
1080         $getdate['weekday'],
1081         $getdate['month']
1082     ) = explode('_', $datestring);
1083
1084     return $getdate;
1085 }
1086
1087 /**
1088  * Given a GMT timestamp (seconds since epoch), offsets it by
1089  * the timezone.  eg 3pm in India is 3pm GMT - 7 * 3600 seconds
1090  *
1091  * @uses HOURSECS
1092  * @param  int $date Timestamp in GMT
1093  * @param float $timezone
1094  * @return int
1095  */
1096 function usertime($date, $timezone=99) {
1097
1098     $timezone = get_user_timezone_offset($timezone);
1099
1100     if (abs($timezone) > 13) {
1101         return $date;
1102     }
1103     return $date - (int)($timezone * HOURSECS);
1104 }
1105
1106 /**
1107  * Given a time, return the GMT timestamp of the most recent midnight
1108  * for the current user.
1109  *
1110  * @param int $date Timestamp in GMT
1111  * @param float $timezone ?
1112  * @return ?
1113  */
1114 function usergetmidnight($date, $timezone=99) {
1115
1116     $timezone = get_user_timezone_offset($timezone);
1117     $userdate = usergetdate($date, $timezone);
1118
1119     // Time of midnight of this user's day, in GMT
1120     return make_timestamp($userdate['year'], $userdate['mon'], $userdate['mday'], 0, 0, 0, $timezone);
1121
1122 }
1123
1124 /**
1125  * Returns a string that prints the user's timezone
1126  *
1127  * @param float $timezone The user's timezone
1128  * @return string
1129  */
1130 function usertimezone($timezone=99) {
1131
1132     $tz = get_user_timezone($timezone);
1133
1134     if (!is_float($tz)) {
1135         return $tz;
1136     }
1137
1138     if(abs($tz) > 13) { // Server time
1139         return get_string('serverlocaltime');
1140     }
1141
1142     if($tz == intval($tz)) {
1143         // Don't show .0 for whole hours
1144         $tz = intval($tz);
1145     }
1146
1147     if($tz == 0) {
1148         return 'GMT';
1149     }
1150     else if($tz > 0) {
1151         return 'GMT+'.$tz;
1152     }
1153     else {
1154         return 'GMT'.$tz;
1155     }
1156
1157 }
1158
1159 /**
1160  * Returns a float which represents the user's timezone difference from GMT in hours
1161  * Checks various settings and picks the most dominant of those which have a value
1162  *
1163  * @uses $CFG
1164  * @uses $USER
1165  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1166  * @return int
1167  */
1168 function get_user_timezone_offset($tz = 99) {
1169
1170     global $USER, $CFG;
1171
1172     $tz = get_user_timezone($tz);
1173
1174     if (is_float($tz)) {
1175         return $tz;
1176     } else {
1177         $tzrecord = get_timezone_record($tz);
1178         if (empty($tzrecord)) {
1179             return 99.0;
1180         }
1181         return (float)$tzrecord->gmtoff / HOURMINS;
1182     }
1183 }
1184
1185 /**
1186  * Returns a float or a string which denotes the user's timezone
1187  * 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)
1188  * means that for this timezone there are also DST rules to be taken into account
1189  * Checks various settings and picks the most dominant of those which have a value
1190  *
1191  * @uses $USER
1192  * @uses $CFG
1193  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1194  * @return mixed
1195  */
1196 function get_user_timezone($tz = 99) {
1197     global $USER, $CFG;
1198
1199     $timezones = array(
1200         $tz,
1201         isset($CFG->forcetimezone) ? $CFG->forcetimezone : 99,
1202         isset($USER->timezone) ? $USER->timezone : 99,
1203         isset($CFG->timezone) ? $CFG->timezone : 99,
1204         );
1205
1206     $tz = 99;
1207
1208     while(($tz == '' || $tz == 99) && $next = each($timezones)) {
1209         $tz = $next['value'];
1210     }
1211
1212     return is_numeric($tz) ? (float) $tz : $tz;
1213 }
1214
1215 /**
1216  * ?
1217  *
1218  * @uses $CFG
1219  * @uses $db
1220  * @param string $timezonename ?
1221  * @return object
1222  */
1223 function get_timezone_record($timezonename) {
1224     global $CFG, $db;
1225     static $cache = NULL;
1226
1227     if ($cache === NULL) {
1228         $cache = array();
1229     }
1230
1231     if (isset($cache[$timezonename])) {
1232         return $cache[$timezonename];
1233     }
1234
1235     return $cache[$timezonename] = get_record_sql('SELECT * FROM '.$CFG->prefix.'timezone
1236                                       WHERE name = '.$db->qstr($timezonename).' ORDER BY year DESC', true);
1237 }
1238
1239 /**
1240  * ?
1241  *
1242  * @uses $CFG
1243  * @uses $USER
1244  * @param ? $fromyear ?
1245  * @param ? $to_year ?
1246  * @return bool
1247  */
1248 function calculate_user_dst_table($from_year = NULL, $to_year = NULL) {
1249     global $CFG, $SESSION;
1250
1251     $usertz = get_user_timezone();
1252
1253     if (is_float($usertz)) {
1254         // Trivial timezone, no DST
1255         return false;
1256     }
1257
1258     if (!empty($SESSION->dst_offsettz) && $SESSION->dst_offsettz != $usertz) {
1259         // We have precalculated values, but the user's effective TZ has changed in the meantime, so reset
1260         unset($SESSION->dst_offsets);
1261         unset($SESSION->dst_range);
1262     }
1263
1264     if (!empty($SESSION->dst_offsets) && empty($from_year) && empty($to_year)) {
1265         // Repeat calls which do not request specific year ranges stop here, we have already calculated the table
1266         // This will be the return path most of the time, pretty light computationally
1267         return true;
1268     }
1269
1270     // Reaching here means we either need to extend our table or create it from scratch
1271
1272     // Remember which TZ we calculated these changes for
1273     $SESSION->dst_offsettz = $usertz;
1274
1275     if(empty($SESSION->dst_offsets)) {
1276         // If we 're creating from scratch, put the two guard elements in there
1277         $SESSION->dst_offsets = array(1 => NULL, 0 => NULL);
1278     }
1279     if(empty($SESSION->dst_range)) {
1280         // If creating from scratch
1281         $from = max((empty($from_year) ? intval(date('Y')) - 3 : $from_year), 1971);
1282         $to   = min((empty($to_year)   ? intval(date('Y')) + 3 : $to_year),   2035);
1283
1284         // Fill in the array with the extra years we need to process
1285         $yearstoprocess = array();
1286         for($i = $from; $i <= $to; ++$i) {
1287             $yearstoprocess[] = $i;
1288         }
1289
1290         // Take note of which years we have processed for future calls
1291         $SESSION->dst_range = array($from, $to);
1292     }
1293     else {
1294         // If needing to extend the table, do the same
1295         $yearstoprocess = array();
1296
1297         $from = max((empty($from_year) ? $SESSION->dst_range[0] : $from_year), 1971);
1298         $to   = min((empty($to_year)   ? $SESSION->dst_range[1] : $to_year),   2035);
1299
1300         if($from < $SESSION->dst_range[0]) {
1301             // Take note of which years we need to process and then note that we have processed them for future calls
1302             for($i = $from; $i < $SESSION->dst_range[0]; ++$i) {
1303                 $yearstoprocess[] = $i;
1304             }
1305             $SESSION->dst_range[0] = $from;
1306         }
1307         if($to > $SESSION->dst_range[1]) {
1308             // Take note of which years we need to process and then note that we have processed them for future calls
1309             for($i = $SESSION->dst_range[1] + 1; $i <= $to; ++$i) {
1310                 $yearstoprocess[] = $i;
1311             }
1312             $SESSION->dst_range[1] = $to;
1313         }
1314     }
1315
1316     if(empty($yearstoprocess)) {
1317         // This means that there was a call requesting a SMALLER range than we have already calculated
1318         return true;
1319     }
1320
1321     // From now on, we know that the array has at least the two guard elements, and $yearstoprocess has the years we need
1322     // Also, the array is sorted in descending timestamp order!
1323
1324     // Get DB data
1325     $presetrecords = get_records('timezone', 'name', $usertz, 'year DESC', 'year, gmtoff, dstoff, dst_month, dst_startday, dst_weekday, dst_skipweeks, dst_time, std_month, std_startday, std_weekday, std_skipweeks, std_time');
1326     if(empty($presetrecords)) {
1327         return false;
1328     }
1329
1330     // Remove ending guard (first element of the array)
1331     reset($SESSION->dst_offsets);
1332     unset($SESSION->dst_offsets[key($SESSION->dst_offsets)]);
1333
1334     // Add all required change timestamps
1335     foreach($yearstoprocess as $y) {
1336         // Find the record which is in effect for the year $y
1337         foreach($presetrecords as $year => $preset) {
1338             if($year <= $y) {
1339                 break;
1340             }
1341         }
1342
1343         $changes = dst_changes_for_year($y, $preset);
1344
1345         if($changes === NULL) {
1346             continue;
1347         }
1348         if($changes['dst'] != 0) {
1349             $SESSION->dst_offsets[$changes['dst']] = $preset->dstoff * MINSECS;
1350         }
1351         if($changes['std'] != 0) {
1352             $SESSION->dst_offsets[$changes['std']] = 0;
1353         }
1354     }
1355
1356     // Put in a guard element at the top
1357     $maxtimestamp = max(array_keys($SESSION->dst_offsets));
1358     $SESSION->dst_offsets[($maxtimestamp + DAYSECS)] = NULL; // DAYSECS is arbitrary, any "small" number will do
1359
1360     // Sort again
1361     krsort($SESSION->dst_offsets);
1362
1363     return true;
1364 }
1365
1366 function dst_changes_for_year($year, $timezone) {
1367
1368     if($timezone->dst_startday == 0 && $timezone->dst_weekday == 0 && $timezone->std_startday == 0 && $timezone->std_weekday == 0) {
1369         return NULL;
1370     }
1371
1372     $monthdaydst = find_day_in_month($timezone->dst_startday, $timezone->dst_weekday, $timezone->dst_month, $year);
1373     $monthdaystd = find_day_in_month($timezone->std_startday, $timezone->std_weekday, $timezone->std_month, $year);
1374
1375     list($dst_hour, $dst_min) = explode(':', $timezone->dst_time);
1376     list($std_hour, $std_min) = explode(':', $timezone->std_time);
1377
1378     $timedst = make_timestamp($year, $timezone->dst_month, $monthdaydst, 0, 0, 0, 99, false);
1379     $timestd = make_timestamp($year, $timezone->std_month, $monthdaystd, 0, 0, 0, 99, false);
1380
1381     // Instead of putting hour and minute in make_timestamp(), we add them afterwards.
1382     // This has the advantage of being able to have negative values for hour, i.e. for timezones
1383     // where GMT time would be in the PREVIOUS day than the local one on which DST changes.
1384
1385     $timedst += $dst_hour * HOURSECS + $dst_min * MINSECS;
1386     $timestd += $std_hour * HOURSECS + $std_min * MINSECS;
1387
1388     return array('dst' => $timedst, 0 => $timedst, 'std' => $timestd, 1 => $timestd);
1389 }
1390
1391 // $time must NOT be compensated at all, it has to be a pure timestamp
1392 function dst_offset_on($time) {
1393     global $SESSION;
1394
1395     if(!calculate_user_dst_table() || empty($SESSION->dst_offsets)) {
1396         return 0;
1397     }
1398
1399     reset($SESSION->dst_offsets);
1400     while(list($from, $offset) = each($SESSION->dst_offsets)) {
1401         if($from <= $time) {
1402             break;
1403         }
1404     }
1405
1406     // This is the normal return path
1407     if($offset !== NULL) {
1408         return $offset;
1409     }
1410
1411     // Reaching this point means we haven't calculated far enough, do it now:
1412     // Calculate extra DST changes if needed and recurse. The recursion always
1413     // moves toward the stopping condition, so will always end.
1414
1415     if($from == 0) {
1416         // We need a year smaller than $SESSION->dst_range[0]
1417         if($SESSION->dst_range[0] == 1971) {
1418             return 0;
1419         }
1420         calculate_user_dst_table($SESSION->dst_range[0] - 5, NULL);
1421         return dst_offset_on($time);
1422     }
1423     else {
1424         // We need a year larger than $SESSION->dst_range[1]
1425         if($SESSION->dst_range[1] == 2035) {
1426             return 0;
1427         }
1428         calculate_user_dst_table(NULL, $SESSION->dst_range[1] + 5);
1429         return dst_offset_on($time);
1430     }
1431 }
1432
1433 function find_day_in_month($startday, $weekday, $month, $year) {
1434
1435     $daysinmonth = days_in_month($month, $year);
1436
1437     if($weekday == -1) {
1438         // Don't care about weekday, so return:
1439         //    abs($startday) if $startday != -1
1440         //    $daysinmonth otherwise
1441         return ($startday == -1) ? $daysinmonth : abs($startday);
1442     }
1443
1444     // From now on we 're looking for a specific weekday
1445
1446     // Give "end of month" its actual value, since we know it
1447     if($startday == -1) {
1448         $startday = -1 * $daysinmonth;
1449     }
1450
1451     // Starting from day $startday, the sign is the direction
1452
1453     if($startday < 1) {
1454
1455         $startday = abs($startday);
1456         $lastmonthweekday  = strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1457
1458         // This is the last such weekday of the month
1459         $lastinmonth = $daysinmonth + $weekday - $lastmonthweekday;
1460         if($lastinmonth > $daysinmonth) {
1461             $lastinmonth -= 7;
1462         }
1463
1464         // Find the first such weekday <= $startday
1465         while($lastinmonth > $startday) {
1466             $lastinmonth -= 7;
1467         }
1468
1469         return $lastinmonth;
1470
1471     }
1472     else {
1473
1474         $indexweekday = strftime('%w', mktime(12, 0, 0, $month, $startday, $year, 0));
1475
1476         $diff = $weekday - $indexweekday;
1477         if($diff < 0) {
1478             $diff += 7;
1479         }
1480
1481         // This is the first such weekday of the month equal to or after $startday
1482         $firstfromindex = $startday + $diff;
1483
1484         return $firstfromindex;
1485
1486     }
1487 }
1488
1489 /**
1490  * Calculate the number of days in a given month
1491  *
1492  * @param int $month The month whose day count is sought
1493  * @param int $year The year of the month whose day count is sought
1494  * @return int
1495  */
1496 function days_in_month($month, $year) {
1497    return intval(date('t', mktime(12, 0, 0, $month, 1, $year, 0)));
1498 }
1499
1500 /**
1501  * Calculate the position in the week of a specific calendar day
1502  *
1503  * @param int $day The day of the date whose position in the week is sought
1504  * @param int $month The month of the date whose position in the week is sought
1505  * @param int $year The year of the date whose position in the week is sought
1506  * @return int
1507  */
1508 function dayofweek($day, $month, $year) {
1509     // I wonder if this is any different from
1510     // strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1511     return intval(date('w', mktime(12, 0, 0, $month, $day, $year, 0)));
1512 }
1513
1514 /// USER AUTHENTICATION AND LOGIN ////////////////////////////////////////
1515
1516 /**
1517  * Makes sure that $USER->sesskey exists, if $USER itself exists. It sets a new sesskey
1518  * if one does not already exist, but does not overwrite existing sesskeys. Returns the
1519  * sesskey string if $USER exists, or boolean false if not.
1520  *
1521  * @uses $USER
1522  * @return string
1523  */
1524 function sesskey() {
1525     global $USER;
1526
1527     if(!isset($USER)) {
1528         return false;
1529     }
1530
1531     if (empty($USER->sesskey)) {
1532         $USER->sesskey = random_string(10);
1533     }
1534
1535     return $USER->sesskey;
1536 }
1537
1538
1539 /**
1540  * For security purposes, this function will check that the currently
1541  * given sesskey (passed as a parameter to the script or this function)
1542  * matches that of the current user.
1543  *
1544  * @param string $sesskey optionally provided sesskey
1545  * @return bool
1546  */
1547 function confirm_sesskey($sesskey=NULL) {
1548     global $USER;
1549
1550     if (!empty($USER->ignoresesskey) || !empty($CFG->ignoresesskey)) {
1551         return true;
1552     }
1553
1554     if (empty($sesskey)) {
1555         $sesskey = required_param('sesskey', PARAM_RAW);  // Check script parameters
1556     }
1557
1558     if (!isset($USER->sesskey)) {
1559         return false;
1560     }
1561
1562     return ($USER->sesskey === $sesskey);
1563 }
1564
1565 /**
1566  * Setup all global $CFG course variables, set locale and also themes
1567  * This function can be used on pages that do not require login instead of require_login()
1568  *
1569  * @param mixed $courseorid id of the course or course object
1570  */
1571 function course_setup($courseorid=0) {
1572     global $COURSE, $CFG, $SITE;
1573
1574 /// Redefine global $COURSE if needed
1575     if (empty($courseorid)) {
1576         // no change in global $COURSE - for backwards compatibiltiy
1577         // if require_rogin() used after require_login($courseid);
1578     } else if (is_object($courseorid)) {
1579         $COURSE = clone($courseorid);
1580     } else {
1581         global $course; // used here only to prevent repeated fetching from DB - may be removed later
1582         if (!empty($course->id) and $course->id == SITEID) {
1583             $COURSE = clone($SITE);
1584         } else if (!empty($course->id) and $course->id == $courseorid) {
1585             $COURSE = clone($course);
1586         } else {
1587             if (!$COURSE = get_record('course', 'id', $courseorid)) {
1588                 error('Invalid course ID');
1589             }
1590         }
1591     }
1592
1593 /// set locale and themes
1594     moodle_setlocale();
1595     theme_setup();
1596
1597 }
1598
1599 /**
1600  * This function checks that the current user is logged in and has the
1601  * required privileges
1602  *
1603  * This function checks that the current user is logged in, and optionally
1604  * whether they are allowed to be in a particular course and view a particular
1605  * course module.
1606  * If they are not logged in, then it redirects them to the site login unless
1607  * $autologinguest is set and {@link $CFG}->autologinguests is set to 1 in which
1608  * case they are automatically logged in as guests.
1609  * If $courseid is given and the user is not enrolled in that course then the
1610  * user is redirected to the course enrolment page.
1611  * If $cm is given and the coursemodule is hidden and the user is not a teacher
1612  * in the course then the user is redirected to the course home page.
1613  *
1614  * @uses $CFG
1615  * @uses $SESSION
1616  * @uses $USER
1617  * @uses $FULLME
1618  * @uses SITEID
1619  * @uses $COURSE
1620  * @param mixed $courseorid id of the course or course object
1621  * @param bool $autologinguest
1622  * @param object $cm course module object
1623  */
1624 function require_login($courseorid=0, $autologinguest=true, $cm=null) {
1625
1626     global $CFG, $SESSION, $USER, $COURSE, $FULLME;
1627
1628 /// setup global $COURSE, themes, language and locale
1629     course_setup($courseorid);
1630
1631 /// If the user is not even logged in yet then make sure they are
1632     if (!isloggedin()) {
1633         //NOTE: $USER->site check was obsoleted by session test cookie,
1634         //      $USER->confirmed test is in login/index.php
1635         $SESSION->wantsurl = $FULLME;
1636         if (!empty($_SERVER['HTTP_REFERER'])) {
1637             $SESSION->fromurl  = $_SERVER['HTTP_REFERER'];
1638         }
1639         if ($autologinguest and !empty($CFG->guestloginbutton) and !empty($CFG->autologinguests) and ($COURSE->id == SITEID or $COURSE->guest) ) {
1640             $loginguest = '?loginguest=true';
1641         } else {
1642             $loginguest = '';
1643         }
1644         if (empty($CFG->loginhttps) or $loginguest) { //do not require https for guest logins
1645             redirect($CFG->wwwroot .'/login/index.php'. $loginguest);
1646         } else {
1647             $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1648             redirect($wwwroot .'/login/index.php');
1649         }
1650         exit;
1651     }
1652
1653 /// loginas as redirection if needed
1654     if ($COURSE->id != SITEID and !empty($USER->realuser)) {
1655         if ($USER->loginascontext->contextlevel == CONTEXT_COURSE) {
1656             if ($USER->loginascontext->instanceid != $COURSE->id) {
1657                 print_error('loginasonecourse', '', $CFG->wwwroot.'/course/view.php?id='.$USER->loginascontext->instanceid);
1658             }
1659         }
1660     }
1661
1662
1663 /// check whether the user should be changing password (but only if it is REALLY them)
1664     $userauth = get_auth_plugin($USER->auth);
1665     if (get_user_preferences('auth_forcepasswordchange') && empty($USER->realuser)) {
1666         if ($userauth->can_change_password()) {
1667             $SESSION->wantsurl = $FULLME;
1668             if ($changeurl = $userauth->change_password_url()) {
1669                 //use plugin custom url
1670                 redirect($changeurl);
1671             } else {
1672                 //use moodle internal method
1673                 if (empty($CFG->loginhttps)) {
1674                     redirect($CFG->wwwroot .'/login/change_password.php');
1675                 } else {
1676                     $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1677                     redirect($wwwroot .'/login/change_password.php');
1678                 }
1679             }
1680         } else {
1681             error(get_string('nopasswordchangeforced', 'auth'));
1682         }
1683     }
1684
1685 /// Check that the user account is properly set up
1686     if (user_not_fully_set_up($USER)) {
1687         $SESSION->wantsurl = $FULLME;
1688         redirect($CFG->wwwroot .'/user/edit.php?id='. $USER->id .'&amp;course='. SITEID);
1689     }
1690
1691 /// Make sure current IP matches the one for this session (if required)
1692     if (!empty($CFG->tracksessionip)) {
1693         if ($USER->sessionIP != md5(getremoteaddr())) {
1694             error(get_string('sessionipnomatch', 'error'));
1695         }
1696     }
1697
1698 /// Make sure the USER has a sesskey set up.  Used for checking script parameters.
1699     sesskey();
1700
1701     // Check that the user has agreed to a site policy if there is one
1702     if (!empty($CFG->sitepolicy)) {
1703         if (!$USER->policyagreed) {
1704             $SESSION->wantsurl = $FULLME;
1705             redirect($CFG->wwwroot .'/user/policy.php');
1706         }
1707     }
1708
1709 /// If the site is currently under maintenance, then print a message
1710     if (!has_capability('moodle/site:config',get_context_instance(CONTEXT_SYSTEM, SITEID))) {
1711         if (file_exists($CFG->dataroot.'/'.SITEID.'/maintenance.html')) {
1712             print_maintenance_message();
1713             exit;
1714         }
1715     }
1716
1717
1718     if ($COURSE->id == SITEID) {
1719 /// We can eliminate hidden site activities straight away
1720         if (!empty($cm) && !$cm->visible and !has_capability('moodle/course:viewhiddenactivities',
1721                                                       get_context_instance(CONTEXT_SYSTEM, SITEID))) {
1722             redirect($CFG->wwwroot, get_string('activityiscurrentlyhidden'));
1723         }
1724         return;
1725
1726     } else {
1727 /// Check if the user can be in a particular course
1728         if (!$context = get_context_instance(CONTEXT_COURSE, $COURSE->id)) {
1729             print_error('nocontext');
1730         }
1731
1732         if (empty($USER->switchrole[$context->id]) &&
1733             !($COURSE->visible && course_parent_visible($COURSE)) &&
1734                !has_capability('moodle/course:viewhiddencourses', get_context_instance(CONTEXT_COURSE, $COURSE->id)) ){
1735             print_header_simple();
1736             notice(get_string('coursehidden'), $CFG->wwwroot .'/');
1737         }
1738
1739     /// Non-guests who don't currently have access, check if they can be allowed in as a guest
1740
1741         if ($USER->username != 'guest' and !has_capability('moodle/course:view', $context)) {
1742             if ($COURSE->guest == 1) {
1743                  // Temporarily assign them guest role for this context, if it fails later user is asked to enrol
1744                  has_capability('clearcache');   // Must clear cache
1745                  $guestcaps = get_role_context_caps($CFG->guestroleid, $context);
1746                  $USER->capabilities = merge_role_caps($USER->capabilities, $guestcaps);
1747             }
1748         }
1749
1750     /// If the user is a guest then treat them according to the course policy about guests
1751
1752         if (has_capability('moodle/legacy:guest', $context, NULL, false)) {
1753             switch ($COURSE->guest) {    /// Check course policy about guest access
1754
1755                 case 1:    /// Guests always allowed
1756                     if (!has_capability('moodle/course:view', $context)) {    // Prohibited by capability
1757                         print_header_simple();
1758                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1759                     }
1760                     if (!empty($cm) and !$cm->visible) { // Not allowed to see module, send to course page
1761                         redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course,
1762                                  get_string('activityiscurrentlyhidden'));
1763                     }
1764
1765                     return;   // User is allowed to see this course
1766
1767                     break;
1768
1769                 case 2:    /// Guests allowed with key
1770                     if (!empty($USER->enrolkey[$COURSE->id])) {   // Set by enrol/manual/enrol.php
1771                         return true;
1772                     }
1773                     //  otherwise drop through to logic below (--> enrol.php)
1774                     break;
1775
1776                 default:    /// Guests not allowed
1777                     print_header_simple('', '', get_string('loggedinasguest'));
1778                     if (empty($USER->switchrole[$context->id])) {  // Normal guest
1779                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1780                     } else {
1781                         notify(get_string('guestsnotallowed', '', format_string($COURSE->fullname)));
1782                         echo '<div class="notifyproblem">'.switchroles_form($COURSE->id).'</div>';
1783                         print_footer($COURSE);
1784                         exit;
1785                     }
1786                     break;
1787             }
1788
1789     /// For non-guests, check if they have course view access
1790
1791         } else if (has_capability('moodle/course:view', $context)) {
1792             if (!empty($USER->realuser)) {   // Make sure the REAL person can also access this course
1793                 if (!has_capability('moodle/course:view', $context, $USER->realuser)) {
1794                     print_header_simple();
1795                     notice(get_string('studentnotallowed', '', fullname($USER, true)), $CFG->wwwroot .'/');
1796                 }
1797             }
1798
1799         /// Make sure they can read this activity too, if specified
1800
1801             if (!empty($cm) and !$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $context)) {
1802                 redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course, get_string('activityiscurrentlyhidden'));
1803             }
1804             return;   // User is allowed to see this course
1805
1806         }
1807
1808
1809     /// Currently not enrolled in the course, so see if they want to enrol
1810         $SESSION->wantsurl = $FULLME;
1811         redirect($CFG->wwwroot .'/course/enrol.php?id='. $COURSE->id);
1812         die;
1813     }
1814 }
1815
1816
1817
1818 /**
1819  * This function just makes sure a user is logged out.
1820  *
1821  * @uses $CFG
1822  * @uses $USER
1823  */
1824 function require_logout() {
1825
1826     global $USER, $CFG, $SESSION;
1827
1828     if (isloggedin()) {
1829         add_to_log(SITEID, "user", "logout", "view.php?id=$USER->id&course=".SITEID, $USER->id, 0, $USER->id);
1830
1831         $authsequence = get_enabled_auth_plugins(); // auths, in sequence
1832         foreach($authsequence as $authname) {
1833             $authplugin = get_auth_plugin($authname);
1834             $authplugin->prelogout_hook();
1835         }
1836     }
1837
1838     if (ini_get_bool("register_globals") and check_php_version("4.3.0")) {
1839         // This method is just to try to avoid silly warnings from PHP 4.3.0
1840         session_unregister("USER");
1841         session_unregister("SESSION");
1842     }
1843
1844     // Initialize variable to pass-by-reference to headers_sent(&$file, &$line)
1845     $file = $line = null;
1846     if (headers_sent($file, $line)) {
1847         error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
1848         error_log('Headers were already sent in file: '.$file.' on line '.$line);
1849     } else {
1850         setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
1851     }
1852
1853     unset($_SESSION['USER']);
1854     unset($_SESSION['SESSION']);
1855
1856     unset($SESSION);
1857     unset($USER);
1858
1859 }
1860
1861 /**
1862  * This is a weaker version of {@link require_login()} which only requires login
1863  * when called from within a course rather than the site page, unless
1864  * the forcelogin option is turned on.
1865  *
1866  * @uses $CFG
1867  * @param mixed $courseorid The course object or id in question
1868  * @param bool $autologinguest Allow autologin guests if that is wanted
1869  * @param object $cm Course activity module if known
1870  */
1871 function require_course_login($courseorid, $autologinguest=true, $cm=null) {
1872     global $CFG;
1873     if (!empty($CFG->forcelogin)) {
1874         // login required for both SITE and courses
1875         require_login($courseorid, $autologinguest, $cm);
1876
1877     } else if (!empty($cm) and !$cm->visible) {
1878         // always login for hidden activities
1879         require_login($courseorid, $autologinguest, $cm);
1880
1881     } else if ((is_object($courseorid) and $courseorid->id == SITEID)
1882           or (!is_object($courseorid) and $courseorid == SITEID)) {
1883         //login for SITE not required
1884         return;
1885
1886     } else {
1887         // course login always required
1888         require_login($courseorid, $autologinguest, $cm);
1889     }
1890 }
1891
1892 /**
1893  * Modify the user table by setting the currently logged in user's
1894  * last login to now.
1895  *
1896  * @uses $USER
1897  * @return bool
1898  */
1899 function update_user_login_times() {
1900     global $USER;
1901
1902     $user = new object();
1903     $USER->lastlogin = $user->lastlogin = $USER->currentlogin;
1904     $USER->currentlogin = $user->lastaccess = $user->currentlogin = time();
1905
1906     $user->id = $USER->id;
1907
1908     return update_record('user', $user);
1909 }
1910
1911 /**
1912  * Determines if a user has completed setting up their account.
1913  *
1914  * @param user $user A {@link $USER} object to test for the existance of a valid name and email
1915  * @return bool
1916  */
1917 function user_not_fully_set_up($user) {
1918     return ($user->username != 'guest' and (empty($user->firstname) or empty($user->lastname) or empty($user->email) or over_bounce_threshold($user)));
1919 }
1920
1921 function over_bounce_threshold($user) {
1922
1923     global $CFG;
1924
1925     if (empty($CFG->handlebounces)) {
1926         return false;
1927     }
1928     // set sensible defaults
1929     if (empty($CFG->minbounces)) {
1930         $CFG->minbounces = 10;
1931     }
1932     if (empty($CFG->bounceratio)) {
1933         $CFG->bounceratio = .20;
1934     }
1935     $bouncecount = 0;
1936     $sendcount = 0;
1937     if ($bounce = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
1938         $bouncecount = $bounce->value;
1939     }
1940     if ($send = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
1941         $sendcount = $send->value;
1942     }
1943     return ($bouncecount >= $CFG->minbounces && $bouncecount/$sendcount >= $CFG->bounceratio);
1944 }
1945
1946 /**
1947  * @param $user - object containing an id
1948  * @param $reset - will reset the count to 0
1949  */
1950 function set_send_count($user,$reset=false) {
1951     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
1952         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
1953         update_record('user_preferences',$pref);
1954     }
1955     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
1956         // make a new one
1957         $pref->name = 'email_send_count';
1958         $pref->value = 1;
1959         $pref->userid = $user->id;
1960         insert_record('user_preferences',$pref, false);
1961     }
1962 }
1963
1964 /**
1965 * @param $user - object containing an id
1966  * @param $reset - will reset the count to 0
1967  */
1968 function set_bounce_count($user,$reset=false) {
1969     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
1970         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
1971         update_record('user_preferences',$pref);
1972     }
1973     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
1974         // make a new one
1975         $pref->name = 'email_bounce_count';
1976         $pref->value = 1;
1977         $pref->userid = $user->id;
1978         insert_record('user_preferences',$pref, false);
1979     }
1980 }
1981
1982 /**
1983  * Keeps track of login attempts
1984  *
1985  * @uses $SESSION
1986  */
1987 function update_login_count() {
1988
1989     global $SESSION;
1990
1991     $max_logins = 10;
1992
1993     if (empty($SESSION->logincount)) {
1994         $SESSION->logincount = 1;
1995     } else {
1996         $SESSION->logincount++;
1997     }
1998
1999     if ($SESSION->logincount > $max_logins) {
2000         unset($SESSION->wantsurl);
2001         error(get_string('errortoomanylogins'));
2002     }
2003 }
2004
2005 /**
2006  * Resets login attempts
2007  *
2008  * @uses $SESSION
2009  */
2010 function reset_login_count() {
2011     global $SESSION;
2012
2013     $SESSION->logincount = 0;
2014 }
2015
2016 function sync_metacourses() {
2017
2018     global $CFG;
2019
2020     if (!$courses = get_records('course', 'metacourse', 1)) {
2021         return;
2022     }
2023
2024     foreach ($courses as $course) {
2025         sync_metacourse($course);
2026     }
2027 }
2028
2029 /**
2030  * Goes through all enrolment records for the courses inside the metacourse and sync with them.
2031  *
2032  * @param mixed $course the metacourse to synch. Either the course object itself, or the courseid.
2033  */
2034 function sync_metacourse($course) {
2035     global $CFG;
2036
2037     // Check the course is valid.
2038     if (!is_object($course)) {
2039         if (!$course = get_record('course', 'id', $course)) {
2040             return false; // invalid course id
2041         }
2042     }
2043
2044     // Check that we actually have a metacourse.
2045     if (empty($course->metacourse)) {
2046         return false;
2047     }
2048
2049     // Get a list of roles that should not be synced.
2050     if (!empty($CFG->nonmetacoursesyncroleids)) {
2051         $roleexclusions = 'ra.roleid NOT IN (' . $CFG->nonmetacoursesyncroleids . ') AND';
2052     } else {
2053         $roleexclusions = '';
2054     }
2055
2056     // Get the context of the metacourse.
2057     $context = get_context_instance(CONTEXT_COURSE, $course->id); // SITEID can not be a metacourse
2058
2059     // We do not ever want to unassign the list of metacourse manager, so get a list of them.
2060     if ($users = get_users_by_capability($context, 'moodle/course:managemetacourse')) {
2061         $managers = array_keys($users);
2062     } else {
2063         $managers = array();
2064     }
2065
2066     // Get assignments of a user to a role that exist in a child course, but
2067     // not in the meta coure. That is, get a list of the assignments that need to be made.
2068     if (!$assignments = get_records_sql("
2069             SELECT
2070                 ra.id, ra.roleid, ra.userid
2071             FROM
2072                 {$CFG->prefix}role_assignments ra,
2073                 {$CFG->prefix}context con,
2074                 {$CFG->prefix}course_meta cm
2075             WHERE
2076                 ra.contextid = con.id AND
2077                 con.contextlevel = " . CONTEXT_COURSE . " AND
2078                 con.instanceid = cm.child_course AND
2079                 cm.parent_course = {$course->id} AND
2080                 $roleexclusions
2081                 NOT EXISTS (
2082                     SELECT 1 FROM
2083                         {$CFG->prefix}role_assignments ra2
2084                     WHERE
2085                         ra2.userid = ra.userid AND
2086                         ra2.roleid = ra.roleid AND
2087                         ra2.contextid = {$context->id}
2088                 )
2089     ")) {
2090         $assignments = array();
2091     }
2092
2093     // Get assignments of a user to a role that exist in the meta course, but
2094     // not in any child courses. That is, get a list of the unassignments that need to be made.
2095     if (!$unassignments = get_records_sql("
2096             SELECT
2097                 ra.id, ra.roleid, ra.userid
2098             FROM
2099                 {$CFG->prefix}role_assignments ra
2100             WHERE
2101                 ra.contextid = {$context->id} AND
2102                 $roleexclusions
2103                 NOT EXISTS (
2104                     SELECT 1 FROM
2105                         {$CFG->prefix}role_assignments ra2,
2106                         {$CFG->prefix}context con2,
2107                         {$CFG->prefix}course_meta cm
2108                     WHERE
2109                         ra2.userid = ra.userid AND
2110                         ra2.roleid = ra.roleid AND
2111                         ra2.contextid = con2.id AND
2112                         con2.contextlevel = " . CONTEXT_COURSE . " AND
2113                         con2.instanceid = cm.child_course AND
2114                         cm.parent_course = {$course->id}
2115                 )
2116     ")) {
2117         $unassignments = array();
2118     }
2119
2120     $success = true;
2121
2122     // Make the unassignments, if they are not managers.
2123     foreach ($unassignments as $unassignment) {
2124         if (!in_array($unassignment->userid, $managers)) {
2125             $success = role_unassign($unassignment->roleid, $unassignment->userid, 0, $context->id) && $success;
2126         }
2127     }
2128
2129     // Make the assignments.
2130     foreach ($assignments as $assignment) {
2131         $success = role_assign($assignment->roleid, $assignment->userid, 0, $context->id) && $success;
2132     }
2133
2134     return $success;
2135
2136 // TODO: finish timeend and timestart
2137 // maybe we could rely on cron job to do the cleaning from time to time
2138 }
2139
2140 /**
2141  * Adds a record to the metacourse table and calls sync_metacoures
2142  */
2143 function add_to_metacourse ($metacourseid, $courseid) {
2144
2145     if (!$metacourse = get_record("course","id",$metacourseid)) {
2146         return false;
2147     }
2148
2149     if (!$course = get_record("course","id",$courseid)) {
2150         return false;
2151     }
2152
2153     if (!$record = get_record("course_meta","parent_course",$metacourseid,"child_course",$courseid)) {
2154         $rec = new object();
2155         $rec->parent_course = $metacourseid;
2156         $rec->child_course = $courseid;
2157         if (!insert_record('course_meta',$rec)) {
2158             return false;
2159         }
2160         return sync_metacourse($metacourseid);
2161     }
2162     return true;
2163
2164 }
2165
2166 /**
2167  * Removes the record from the metacourse table and calls sync_metacourse
2168  */
2169 function remove_from_metacourse($metacourseid, $courseid) {
2170
2171     if (delete_records('course_meta','parent_course',$metacourseid,'child_course',$courseid)) {
2172         return sync_metacourse($metacourseid);
2173     }
2174     return false;
2175 }
2176
2177
2178 /**
2179  * Determines if a user is currently logged in
2180  *
2181  * @uses $USER
2182  * @return bool
2183  */
2184 function isloggedin() {
2185     global $USER;
2186
2187     return (!empty($USER->id));
2188 }
2189
2190 /**
2191  * Determines if a user is logged in as real guest user with username 'guest'.
2192  * This function is similar to original isguest() in 1.6 and earlier.
2193  * Current isguest() is deprecated - do not use it anymore.
2194  *
2195  * @param $user mixed user object or id, $USER if not specified
2196  * @return bool true if user is the real guest user, false if not logged in or other user
2197  */
2198 function isguestuser($user=NULL) {
2199     global $USER;
2200     if ($user === NULL) {
2201         $user = $USER;
2202     } else if (is_numeric($user)) {
2203         $user = get_record('user', 'id', $user, '', '', '', '', 'id, username');
2204     }
2205
2206     if (empty($user->id)) {
2207         return false; // not logged in, can not be guest
2208     }
2209
2210     return ($user->username == 'guest');
2211 }
2212
2213 /**
2214  * Determines if the currently logged in user is in editing mode
2215  *
2216  * @uses $USER
2217  * @param int $courseid The id of the course being tested
2218  * @param user $user A {@link $USER} object. If null then the currently logged in user is used.
2219  * @return bool
2220  */
2221 function isediting($courseid, $user=NULL) {
2222     global $USER;
2223     if (!$user) {
2224         $user = $USER;
2225     }
2226     if (empty($user->editing)) {
2227         return false;
2228     }
2229
2230     $capcheck = false;
2231     $coursecontext = get_context_instance(CONTEXT_COURSE, $courseid);
2232
2233     if (has_capability('moodle/course:manageactivities', $coursecontext) ||
2234         has_capability('moodle/site:manageblocks', $coursecontext)) {
2235         $capcheck = true;
2236     } else {
2237         // loop through all child context, see if user has moodle/course:manageactivities or moodle/site:manageblocks
2238         if ($children = get_child_contexts($coursecontext)) {
2239             foreach ($children as $child) {
2240                 $childcontext = get_record('context', 'id', $child);
2241                 if (has_capability('moodle/course:manageactivities', $childcontext) ||
2242                     has_capability('moodle/site:manageblocks', $childcontext)) {
2243                     $capcheck = true;
2244                     break;
2245                 }
2246             }
2247         }
2248     }
2249
2250     return ($user->editing && $capcheck);
2251     //return ($user->editing and has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $courseid)));
2252 }
2253
2254 /**
2255  * Determines if the logged in user is currently moving an activity
2256  *
2257  * @uses $USER
2258  * @param int $courseid The id of the course being tested
2259  * @return bool
2260  */
2261 function ismoving($courseid) {
2262     global $USER;
2263
2264     if (!empty($USER->activitycopy)) {
2265         return ($USER->activitycopycourse == $courseid);
2266     }
2267     return false;
2268 }
2269
2270 /**
2271  * Given an object containing firstname and lastname
2272  * values, this function returns a string with the
2273  * full name of the person.
2274  * The result may depend on system settings
2275  * or language.  'override' will force both names
2276  * to be used even if system settings specify one.
2277  *
2278  * @uses $CFG
2279  * @uses $SESSION
2280  * @param object $user A {@link $USER} object to get full name of
2281  * @param bool $override If true then the name will be first name followed by last name rather than adhering to fullnamedisplay setting.
2282  */
2283 function fullname($user, $override=false) {
2284
2285     global $CFG, $SESSION;
2286
2287     if (!isset($user->firstname) and !isset($user->lastname)) {
2288         return '';
2289     }
2290
2291     if (!$override) {
2292         if (!empty($CFG->forcefirstname)) {
2293             $user->firstname = $CFG->forcefirstname;
2294         }
2295         if (!empty($CFG->forcelastname)) {
2296             $user->lastname = $CFG->forcelastname;
2297         }
2298     }
2299
2300     if (!empty($SESSION->fullnamedisplay)) {
2301         $CFG->fullnamedisplay = $SESSION->fullnamedisplay;
2302     }
2303
2304     if ($CFG->fullnamedisplay == 'firstname lastname') {
2305         return $user->firstname .' '. $user->lastname;
2306
2307     } else if ($CFG->fullnamedisplay == 'lastname firstname') {
2308         return $user->lastname .' '. $user->firstname;
2309
2310     } else if ($CFG->fullnamedisplay == 'firstname') {
2311         if ($override) {
2312             return get_string('fullnamedisplay', '', $user);
2313         } else {
2314             return $user->firstname;
2315         }
2316     }
2317
2318     return get_string('fullnamedisplay', '', $user);
2319 }
2320
2321 /**
2322  * Sets a moodle cookie with an encrypted string
2323  *
2324  * @uses $CFG
2325  * @uses DAYSECS
2326  * @uses HOURSECS
2327  * @param string $thing The string to encrypt and place in a cookie
2328  */
2329 function set_moodle_cookie($thing) {
2330     global $CFG;
2331
2332     if ($thing == 'guest') {  // Ignore guest account
2333         return;
2334     }
2335
2336     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2337
2338     $days = 60;
2339     $seconds = DAYSECS*$days;
2340
2341     setCookie($cookiename, '', time() - HOURSECS, '/');
2342     setCookie($cookiename, rc4encrypt($thing), time()+$seconds, '/');
2343 }
2344
2345 /**
2346  * Gets a moodle cookie with an encrypted string
2347  *
2348  * @uses $CFG
2349  * @return string
2350  */
2351 function get_moodle_cookie() {
2352     global $CFG;
2353
2354     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2355
2356     if (empty($_COOKIE[$cookiename])) {
2357         return '';
2358     } else {
2359         $thing = rc4decrypt($_COOKIE[$cookiename]);
2360         return ($thing == 'guest') ? '': $thing;  // Ignore guest account
2361     }
2362 }
2363
2364 /**
2365  * Returns whether a given authentication plugin exists.
2366  *
2367  * @uses $CFG
2368  * @param string $auth Form of authentication to check for. Defaults to the
2369  *        global setting in {@link $CFG}.
2370  * @return boolean Whether the plugin is available.
2371  */
2372 function exists_auth_plugin($auth) {
2373     global $CFG;
2374
2375     if (file_exists("{$CFG->dirroot}/auth/$auth/auth.php")) {
2376         return is_readable("{$CFG->dirroot}/auth/$auth/auth.php");
2377     }
2378     return false;
2379 }
2380
2381 /**
2382  * Checks if a given plugin is in the list of enabled authentication plugins.
2383  *
2384  * @param string $auth Authentication plugin.
2385  * @return boolean Whether the plugin is enabled.
2386  */
2387 function is_enabled_auth($auth) {
2388     if (empty($auth)) {
2389         return false;
2390     }
2391
2392     $enabled = get_enabled_auth_plugins();
2393
2394     return in_array($auth, $enabled);
2395 }
2396
2397 /**
2398  * Returns an authentication plugin instance.
2399  *
2400  * @uses $CFG
2401  * @param string $auth name of authentication plugin
2402  * @return object An instance of the required authentication plugin.
2403  */
2404 function get_auth_plugin($auth) {
2405     global $CFG;
2406
2407     // check the plugin exists first
2408     if (! exists_auth_plugin($auth)) {
2409         error("Authentication plugin '$auth' not found.");
2410     }
2411
2412     // return auth plugin instance
2413     require_once "{$CFG->dirroot}/auth/$auth/auth.php";
2414     $class = "auth_plugin_$auth";
2415     return new $class;
2416 }
2417
2418 /**
2419  * Returns array of active auth plugins.
2420  *
2421  * @param bool $fix fix $CFG->auth if needed
2422  * @return array
2423  */
2424 function get_enabled_auth_plugins($fix=false) {
2425     global $CFG;
2426
2427     $default = array('manual', 'nologin');
2428
2429     if (empty($CFG->auth)) {
2430         $auths = array();
2431     } else {
2432         $auths = explode(',', $CFG->auth);
2433     }
2434
2435     if ($fix) {
2436         $auths = array_unique($auths);
2437         foreach($auths as $k=>$authname) {
2438             if (!exists_auth_plugin($authname) or in_array($authname, $default)) {
2439                 unset($auths[$k]);
2440             }
2441         }
2442         $newconfig = implode(',', $auths);
2443         if (!isset($CFG->auth) or $newconfig != $CFG->auth) {
2444             set_config('auth', $newconfig);
2445         }
2446     }
2447
2448     return (array_merge($default, $auths));
2449 }
2450
2451 /**
2452  * Returns true if an internal authentication method is being used.
2453  * if method not specified then, global default is assumed
2454  *
2455  * @uses $CFG
2456  * @param string $auth Form of authentication required
2457  * @return bool
2458  */
2459 function is_internal_auth($auth) {
2460     $authplugin = get_auth_plugin($auth); // throws error if bad $auth
2461     return $authplugin->is_internal();
2462 }
2463
2464 /**
2465  * Returns an array of user fields
2466  *
2467  * @uses $CFG
2468  * @uses $db
2469  * @return array User field/column names
2470  */
2471 function get_user_fieldnames() {
2472
2473     global $CFG, $db;
2474
2475     $fieldarray = $db->MetaColumnNames($CFG->prefix.'user');
2476     unset($fieldarray['ID']);
2477
2478     return $fieldarray;
2479 }
2480
2481 /**
2482  * Creates a bare-bones user record
2483  *
2484  * @uses $CFG
2485  * @param string $username New user's username to add to record
2486  * @param string $password New user's password to add to record
2487  * @param string $auth Form of authentication required
2488  * @return object A {@link $USER} object
2489  * @todo Outline auth types and provide code example
2490  */
2491 function create_user_record($username, $password, $auth='manual') {
2492     global $CFG;
2493
2494     //just in case check text case
2495     $username = trim(moodle_strtolower($username));
2496
2497     $authplugin = get_auth_plugin($auth);
2498
2499     if ($newinfo = $authplugin->get_userinfo($username)) {
2500         $newinfo = truncate_userinfo($newinfo);
2501         foreach ($newinfo as $key => $value){
2502             $newuser->$key = addslashes($value);
2503         }
2504     }
2505
2506     if (!empty($newuser->email)) {
2507         if (email_is_not_allowed($newuser->email)) {
2508             unset($newuser->email);
2509         }
2510     }
2511
2512     $newuser->auth = $auth;
2513     $newuser->username = $username;
2514
2515     // fix for MDL-8480
2516     // user CFG lang for user if $newuser->lang is empty
2517     // or $user->lang is not an installed language
2518     $sitelangs = array_keys(get_list_of_languages());
2519     if (empty($newuser->lang) || !in_array($newuser->lang, $sitelangs)) {
2520         $newuser -> lang = $CFG->lang;
2521     }
2522     $newuser->confirmed = 1;
2523     $newuser->lastip = getremoteaddr();
2524     $newuser->timemodified = time();
2525     $newuser->mnethostid = $CFG->mnet_localhost_id;
2526
2527     if (insert_record('user', $newuser)) {
2528         $user = get_complete_user_data('username', $newuser->username);
2529         if(!empty($CFG->{'auth_'.$newuser->auth.'_forcechangepassword'})){
2530             set_user_preference('auth_forcepasswordchange', 1, $user->id);
2531         }
2532         update_internal_user_password($user, $password);
2533         return $user;
2534     }
2535     return false;
2536 }
2537
2538 /**
2539  * Will update a local user record from an external source
2540  *
2541  * @uses $CFG
2542  * @param string $username New user's username to add to record
2543  * @return user A {@link $USER} object
2544  */
2545 function update_user_record($username, $authplugin) {
2546     $username = trim(moodle_strtolower($username)); /// just in case check text case
2547
2548     $oldinfo = get_record('user', 'username', $username, '','','','', 'username, auth');
2549     $userauth = get_auth_plugin($oldinfo->auth);
2550
2551     if ($newinfo = $userauth->get_userinfo($username)) {
2552         $newinfo = truncate_userinfo($newinfo);
2553         foreach ($newinfo as $key => $value){
2554             $confkey = 'field_updatelocal_' . $key;
2555             if (!empty($userauth->config->$confkey) and $userauth->config->$confkey === 'onlogin') {
2556                 $value = addslashes(stripslashes($value));   // Just in case
2557                 set_field('user', $key, $value, 'username', $username)
2558                     or error_log("Error updating $key for $username");
2559             }
2560         }
2561     }
2562
2563     return get_complete_user_data('username', $username);
2564 }
2565
2566 function truncate_userinfo($info) {
2567 /// will truncate userinfo as it comes from auth_get_userinfo (from external auth)
2568 /// which may have large fields
2569
2570     // define the limits
2571     $limit = array(
2572                     'username'    => 100,
2573                     'idnumber'    =>  64,
2574                     'firstname'   => 100,
2575                     'lastname'    => 100,
2576                     'email'       => 100,
2577                     'icq'         =>  15,
2578                     'phone1'      =>  20,
2579                     'phone2'      =>  20,
2580                     'institution' =>  40,
2581                     'department'  =>  30,
2582                     'address'     =>  70,
2583                     'city'        =>  20,
2584                     'country'     =>   2,
2585                     'url'         => 255,
2586                     );
2587
2588     // apply where needed
2589     foreach (array_keys($info) as $key) {
2590         if (!empty($limit[$key])) {
2591             $info[$key] = trim(substr($info[$key],0, $limit[$key]));
2592         }
2593     }
2594
2595     return $info;
2596 }
2597
2598 /**
2599  * Retrieve the guest user object
2600  *
2601  * @uses $CFG
2602  * @return user A {@link $USER} object
2603  */
2604 function guest_user() {
2605     global $CFG;
2606
2607     if ($newuser = get_record('user', 'username', 'guest', 'mnethostid',  $CFG->mnet_localhost_id)) {
2608         $newuser->confirmed = 1;
2609         $newuser->lang = $CFG->lang;
2610         $newuser->lastip = getremoteaddr();
2611     }
2612
2613     return $newuser;
2614 }
2615
2616 /**
2617  * Given a username and password, this function looks them
2618  * up using the currently selected authentication mechanism,
2619  * and if the authentication is successful, it returns a
2620  * valid $user object from the 'user' table.
2621  *
2622  * Uses auth_ functions from the currently active auth module
2623  *
2624  * @uses $CFG
2625  * @param string $username  User's username (with system magic quotes)
2626  * @param string $password  User's password (with system magic quotes)
2627  * @return user|flase A {@link $USER} object or false if error
2628  */
2629 function authenticate_user_login($username, $password) {
2630
2631     global $CFG;
2632
2633     $authsenabled = get_enabled_auth_plugins();
2634
2635     if ($user = get_complete_user_data('username', $username)) {
2636         $auth = empty($user->auth) ? 'manual' : $user->auth;  // use manual if auth not set
2637         if ($auth=='nologin' or !is_enabled_auth($auth)) {
2638             add_to_log(0, 'login', 'error', 'index.php', $username);
2639             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Disabled Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2640             return false;
2641         }
2642         if (!empty($user->deleted)) {
2643             add_to_log(0, 'login', 'error', 'index.php', $username);
2644             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Deleted Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2645             return false;
2646         }
2647         $auths = array($auth);
2648
2649     } else {
2650         $auths = $authsenabled;
2651         $user = new object();
2652         $user->id = 0;     // User does not exist
2653     }
2654
2655     foreach ($auths as $auth) {
2656         $authplugin = get_auth_plugin($auth);
2657
2658         // on auth fail fall through to the next plugin
2659         if (!$authplugin->user_login($username, $password)) {
2660             continue;
2661         }
2662
2663         // successful authentication
2664         if ($user->id) {                          // User already exists in database
2665             if (empty($user->auth)) {             // For some reason auth isn't set yet
2666                 set_field('user', 'auth', $auth, 'username', $username);
2667                 $user->auth = $auth;
2668             }
2669
2670             update_internal_user_password($user, $password); // just in case salt or encoding were changed (magic quotes too one day)
2671
2672             if (!$authplugin->is_internal()) {            // update user record from external DB
2673                 $user = update_user_record($username, get_auth_plugin($user->auth));
2674             }
2675         } else {
2676             // if user not found, create him
2677             $user = create_user_record($username, $password, $auth);
2678         }
2679
2680         $authplugin->sync_roles($user);
2681
2682         foreach ($authsenabled as $hau) {
2683             $hauth = get_auth_plugin($hau);
2684             $hauth->user_authenticated_hook($user, $username, $password);
2685         }
2686
2687     /// Log in to a second system if necessary
2688     /// NOTICE: /sso/ will be moved to auth and deprecated soon; use user_authenticated_hook() instead
2689         if (!empty($CFG->sso)) {
2690             include_once($CFG->dirroot .'/sso/'. $CFG->sso .'/lib.php');
2691             if (function_exists('sso_user_login')) {
2692                 if (!sso_user_login($username, $password)) {   // Perform the signon process
2693                     notify('Second sign-on failed');
2694                 }
2695             }
2696         }
2697
2698         return $user;
2699
2700     }
2701
2702     // failed if all the plugins have failed
2703     add_to_log(0, 'login', 'error', 'index.php', $username);
2704     error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Failed Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2705     return false;
2706 }
2707
2708 /**
2709  * Compare password against hash stored in internal user table.
2710  * If necessary it also updates the stored hash to new format.
2711  *
2712  * @param object user
2713  * @param string plain text password
2714  * @return bool is password valid?
2715  */
2716 function validate_internal_user_password(&$user, $password) {
2717     global $CFG;
2718
2719     if (!isset($CFG->passwordsaltmain)) {
2720         $CFG->passwordsaltmain = '';
2721     }
2722
2723     $validated = false;
2724
2725     // get password original encoding in case it was not updated to unicode yet
2726     $textlib = textlib_get_instance();
2727     $convpassword = $textlib->convert($password, 'utf-8', get_string('oldcharset'));
2728
2729     if ($user->password == md5($password.$CFG->passwordsaltmain) or $user->password == md5($password)
2730         or $user->password == md5($convpassword.$CFG->passwordsaltmain) or $user->password == md5($convpassword)) {
2731         $validated = true;
2732     } else {
2733         for ($i=1; $i<=20; $i++) { //20 alternative salts should be enough, right?
2734             $alt = 'passwordsaltalt'.$i;
2735             if (!empty($CFG->$alt)) {
2736                 if ($user->password == md5($password.$CFG->$alt) or $user->password == md5($convpassword.$CFG->$alt)) {
2737                     $validated = true;
2738                     break;
2739                 }
2740             }
2741         }
2742     }
2743
2744     if ($validated) {
2745         // force update of password hash using latest main password salt and encoding if needed
2746         update_internal_user_password($user, $password);
2747     }
2748
2749     return $validated;
2750 }
2751
2752 /**
2753  * Calculate hashed value from password using current hash mechanism.
2754  *
2755  * @param string password
2756  * @return string password hash
2757  */
2758 function hash_internal_user_password($password) {
2759     global $CFG;
2760
2761     if (isset($CFG->passwordsaltmain)) {
2762         return md5($password.$CFG->passwordsaltmain);
2763     } else {
2764         return md5($password);
2765     }
2766 }
2767
2768 /**
2769  * Update pssword hash in user object.
2770  *
2771  * @param object user
2772  * @param string plain text password
2773  * @param bool store changes also in db, default true
2774  * @return true if hash changed
2775  */
2776 function update_internal_user_password(&$user, $password) {
2777     global $CFG;
2778
2779     $authplugin = get_auth_plugin($user->auth);
2780     if (!empty($authplugin->config->preventpassindb)) {
2781         $hashedpassword = 'not cached';
2782     } else {
2783         $hashedpassword = hash_internal_user_password($password);
2784     }
2785
2786     return set_field('user', 'password',  $hashedpassword, 'id', $user->id);
2787 }
2788
2789 /**
2790  * Get a complete user record, which includes all the info
2791  * in the user record
2792  * Intended for setting as $USER session variable
2793  *
2794  * @uses $CFG
2795  * @uses SITEID
2796  * @param string $field The user field to be checked for a given value.
2797  * @param string $value The value to match for $field.
2798  * @return user A {@link $USER} object.
2799  */
2800 function get_complete_user_data($field, $value, $mnethostid=null) {
2801
2802     global $CFG;
2803
2804     if (!$field || !$value) {
2805         return false;
2806     }
2807
2808 /// Build the WHERE clause for an SQL query
2809
2810     $constraints = $field .' = \''. $value .'\' AND deleted <> \'1\'';
2811
2812     if (is_null($mnethostid)) {
2813         // if null, we restrict to local users
2814         // ** testing for local user can be done with
2815         //    mnethostid = $CFG->mnet_localhost_id
2816         //    or with
2817         //    auth != 'mnet'
2818         //    but the first one is FAST with our indexes
2819         $mnethostid = $CFG->mnet_localhost_id;
2820     }
2821     $mnethostid = (int)$mnethostid;
2822     $constraints .= ' AND mnethostid = \''.$mnethostid.'\'';
2823
2824 /// Get all the basic user data
2825
2826     if (! $user = get_record_select('user', $constraints)) {
2827         return false;
2828     }
2829
2830 /// Get various settings and preferences
2831
2832     if ($displays = get_records('course_display', 'userid', $user->id)) {
2833         foreach ($displays as $display) {
2834             $user->display[$display->course] = $display->display;
2835         }
2836     }
2837
2838     $user->preference = get_user_preferences(null, null, $user->id);
2839
2840     if ($lastaccesses = get_records('user_lastaccess', 'userid', $user->id)) {
2841         foreach ($lastaccesses as $lastaccess) {
2842             $user->lastcourseaccess[$lastaccess->courseid] = $lastaccess->timeaccess;
2843         }
2844     }
2845
2846     if ($groupids = groups_get_all_groups_for_user($user->id)) { //TODO:check.
2847         foreach ($groupids as $groupid) {
2848             $courseid = groups_get_course($groupid);
2849             //change this to 2D array so we can put multiple groups in a course
2850             $user->groupmember[$courseid][] = $groupid;
2851         }
2852     }
2853
2854 /// Rewrite some variables if necessary
2855     if (!empty($user->description)) {
2856         $user->description = true;   // No need to cart all of it around
2857     }
2858     if ($user->username == 'guest') {
2859         $user->lang       = $CFG->lang;               // Guest language always same as site
2860         $user->firstname  = get_string('guestuser');  // Name always in current language
2861         $user->lastname   = ' ';
2862     }
2863
2864     $user->sesskey  = random_string(10);
2865     $user->sessionIP = md5(getremoteaddr());   // Store the current IP in the session
2866
2867     return $user;
2868 }
2869
2870 /**
2871  * @uses $CFG
2872  * @param string $password the password to be checked agains the password policy
2873  * @param string $errmsg the error message to display when the password doesn't comply with the policy.
2874  * @return bool true if the password is valid according to the policy. false otherwise.
2875  */
2876 function check_password_policy($password, &$errmsg) {
2877     global $CFG;
2878
2879     if (empty($CFG->passwordpolicy)) {
2880         return true;
2881     }
2882
2883     $textlib = new textlib();
2884     $errmsg = '';
2885     if ($textlib->strlen($password) < $CFG->minpasswordlength) {
2886         $errmsg = get_string('errorminpasswordlength', 'auth', $CFG->minpasswordlength);
2887
2888     } else if (preg_match_all('/[[:digit:]]/u', $password, $matches) < $CFG->minpassworddigits) {
2889         $errmsg = get_string('errorminpassworddigits', 'auth', $CFG->minpassworddigits);
2890
2891     } else if (preg_match_all('/[[:lower:]]/u', $password, $matches) < $CFG->minpasswordlower) {
2892         $errmsg = get_string('errorminpasswordlower', 'auth', $CFG->minpasswordlower);
2893
2894     } else if (preg_match_all('/[[:upper:]]/u', $password, $matches) < $CFG->minpasswordupper) {
2895         $errmsg = get_string('errorminpasswordupper', 'auth', $CFG->minpasswordupper);
2896
2897     } else if (preg_match_all('/[^[:upper:][:lower:][:digit:]]/u', $password, $matches) < $CFG->minpasswordnonalphanum) {
2898         $errmsg = get_string('errorminpasswordnonalphanum', 'auth', $CFG->minpasswordnonalphanum);
2899
2900     } else if ($password == 'admin' or $password == 'password') {
2901         $errmsg = get_string('unsafepassword');
2902     }
2903
2904     if ($errmsg == '') {
2905         return true;
2906     } else {
2907         return false;
2908     }
2909 }
2910
2911
2912 /**
2913  * When logging in, this function is run to set certain preferences
2914  * for the current SESSION
2915  */
2916 function set_login_session_preferences() {
2917     global $SESSION, $CFG;
2918
2919     $SESSION->justloggedin = true;
2920
2921     unset($SESSION->lang);
2922
2923     // Restore the calendar filters, if saved
2924     if (intval(get_user_preferences('calendar_persistflt', 0))) {
2925         include_once($CFG->dirroot.'/calendar/lib.php');
2926         calendar_set_filters_status(get_user_preferences('calendav_savedflt', 0xff));
2927     }
2928 }
2929
2930
2931 /**
2932  * Delete a course, including all related data from the database,
2933  * and any associated files from the moodledata folder.
2934  *
2935  * @param int $courseid The id of the course to delete.
2936  * @param bool $showfeedback Whether to display notifications of each action the function performs.
2937  * @return bool true if all the removals succeeded. false if there were any failures. If this
2938  *             method returns false, some of the removals will probably have succeeded, and others
2939  *             failed, but you have no way of knowing which.
2940  */
2941 function delete_course($courseid, $showfeedback = true) {
2942     global $CFG;
2943     $result = true;
2944
2945     if (!remove_course_contents($courseid, $showfeedback)) {
2946         if ($showfeedback) {
2947             notify("An error occurred while deleting some of the course contents.");
2948         }
2949         $result = false;
2950     }
2951
2952     if (!delete_records("course", "id", $courseid)) {
2953         if ($showfeedback) {
2954             notify("An error occurred while deleting the main course record.");
2955         }
2956         $result = false;
2957     }
2958
2959     if (!delete_records('context', 'contextlevel', CONTEXT_COURSE, 'instanceid', $courseid)) {
2960         if ($showfeedback) {
2961             notify("An error occurred while deleting the main context record.");
2962         }
2963         $result = false;
2964     }
2965
2966     if (!fulldelete($CFG->dataroot.'/'.$courseid)) {
2967         if ($showfeedback) {
2968             notify("An error occurred while deleting the course files.");
2969         }
2970         $result = false;
2971     }
2972
2973     return $result;
2974 }
2975
2976 /**
2977  * Clear a course out completely, deleting all content
2978  * but don't delete the course itself
2979  *
2980  * @uses $CFG
2981  * @param int $courseid The id of the course that is being deleted
2982  * @param bool $showfeedback Whether to display notifications of each action the function performs.
2983  * @return bool true if all the removals succeeded. false if there were any failures. If this
2984  *             method returns false, some of the removals will probably have succeeded, and others
2985  *             failed, but you have no way of knowing which.
2986  */
2987 function remove_course_contents($courseid, $showfeedback=true) {
2988
2989     global $CFG;
2990
2991     $result = true;
2992
2993     if (! $course = get_record('course', 'id', $courseid)) {
2994         error('Course ID was incorrect (can\'t find it)');
2995     }
2996
2997     $strdeleted = get_string('deleted');
2998
2999 /// First delete every instance of every module
3000
3001     if ($allmods = get_records('modules') ) {
3002         foreach ($allmods as $mod) {
3003             $modname = $mod->name;
3004             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3005             $moddelete = $modname .'_delete_instance';       // Delete everything connected to an instance
3006             $moddeletecourse = $modname .'_delete_course';   // Delete other stray stuff (uncommon)
3007             $count=0;
3008             if (file_exists($modfile)) {
3009                 include_once($modfile);
3010                 if (function_exists($moddelete)) {
3011                     if ($instances = get_records($modname, 'course', $course->id)) {
3012                         foreach ($instances as $instance) {
3013                             if ($cm = get_coursemodule_from_instance($modname, $instance->id, $course->id)) {
3014                                 delete_context(CONTEXT_MODULE, $cm->id);
3015                             }
3016                             if ($moddelete($instance->id)) {
3017                                 $count++;
3018
3019                             } else {
3020                                 notify('Could not delete '. $modname .' instance '. $instance->id .' ('. format_string($instance->name) .')');
3021                                 $result = false;
3022                             }
3023                         }
3024                     }
3025                 } else {
3026                     notify('Function '. $moddelete() .'doesn\'t exist!');
3027                     $result = false;
3028                 }
3029
3030                 if (function_exists($moddeletecourse)) {
3031                     $moddeletecourse($course, $showfeedback);
3032                 }
3033             }
3034             if ($showfeedback) {
3035                 notify($strdeleted .' '. $count .' x '. $modname);
3036             }
3037         }
3038     } else {
3039         error('No modules are installed!');
3040     }
3041
3042 /// Give local code a chance to delete its references to this course.
3043     require_once('locallib.php');
3044     notify_local_delete_course($courseid, $showfeedback);
3045
3046 /// Delete course blocks
3047
3048     if ($blocks = get_records_sql("SELECT *
3049                                    FROM {$CFG->prefix}block_instance
3050                                    WHERE pagetype = '".PAGE_COURSE_VIEW."'
3051                                    AND pageid = $course->id")) {
3052         if (delete_records('block_instance', 'pagetype', PAGE_COURSE_VIEW, 'pageid', $course->id)) {
3053             if ($showfeedback) {
3054                 notify($strdeleted .' block_instance');
3055             }
3056
3057             require_once($CFG->libdir.'/blocklib.php');
3058             foreach ($blocks as $block) {  /// Delete any associated contexts for this block
3059
3060                 // Block instances are rarely created. Since the block instance is gone from the above delete
3061                 // statement, calling delete_context() will generate a warning as get_context_instance could
3062                 // no longer create the context as the block is already gone.
3063                 if (record_exists('context', 'contextlevel', CONTEXT_BLOCK, 'instanceid', $block->id)) {
3064                     delete_context(CONTEXT_BLOCK, $block->id);
3065                 }
3066
3067                 // fix for MDL-7164
3068                 // Get the block object and call instance_delete()
3069                 if (!$record = blocks_get_record($block->blockid)) {
3070                     $result = false;
3071                     continue;
3072                 }
3073                 if (!$obj = block_instance($record->name, $block)) {
3074                     $result = false;
3075                     continue;
3076                 }
3077                 // Return value ignored, in core mods this does not do anything, but just in case
3078                 // third party blocks might have stuff to clean up
3079                 // we execute this anyway
3080                 $obj->instance_delete();
3081             }
3082         } else {
3083             $result = false;
3084         }
3085     }
3086
3087 /// Delete any groups, removing members and grouping/course links first.
3088     //TODO: If groups or groupings are to be shared between courses, think again!
3089     if ($groupids = groups_get_groups($course->id)) {
3090         foreach ($groupids as $groupid) {
3091             if (groups_remove_all_members($groupid)) {
3092                 if ($showfeedback) {
3093                     notify($strdeleted .' groups_members');
3094                 }
3095             } else {
3096                 $result = false;
3097             }
3098             /// Delete any associated context for this group ??
3099             delete_context(CONTEXT_GROUP, $groupid);
3100
3101             if (groups_delete_group($groupid)) {
3102                 if ($showfeedback) {
3103                     notify($strdeleted .' groups');
3104                 }
3105             } else {
3106                 $result = false;
3107             }
3108         }
3109     }
3110 /// Delete any groupings.
3111     $result = groups_delete_all_groupings($course->id);
3112     if ($result && $showfeedback) {
3113         notify($strdeleted .' groupings');
3114     }
3115
3116 /// Delete all related records in other tables that may have a courseid
3117 /// This array stores the tables that need to be cleared, as
3118 /// table_name => column_name that contains the course id.
3119
3120     $tablestoclear = array(
3121         'event' => 'courseid', // Delete events
3122         'log' => 'course', // Delete logs
3123         'course_sections' => 'course', // Delete any course stuff
3124         'course_modules' => 'course',
3125         'grade_category' => 'courseid', // Delete gradebook stuff
3126         'grade_exceptions' => 'courseid',
3127         'grade_item' => 'courseid',
3128         'grade_letter' => 'courseid',
3129         'grade_preferences' => 'courseid',
3130         'backup_courses' => 'courseid', // Delete scheduled backup stuff
3131         'backup_log' => 'courseid'
3132     );
3133     foreach ($tablestoclear as $table => $col) {
3134         if (delete_records($table, $col, $course->id)) {
3135             if ($showfeedback) {
3136                 notify($strdeleted . ' ' . $table);
3137             }
3138         } else {
3139             $result = false;
3140         }
3141     }
3142
3143
3144 /// Clean up metacourse stuff
3145
3146     if ($course->metacourse) {
3147         delete_records("course_meta","parent_course",$course->id);
3148         sync_metacourse($course->id); // have to do it here so the enrolments get nuked. sync_metacourses won't find it without the id.
3149         if ($showfeedback) {
3150             notify("$strdeleted course_meta");
3151         }
3152     } else {
3153         if ($parents = get_records("course_meta","child_course",$course->id)) {
3154             foreach ($parents as $parent) {
3155                 remove_from_metacourse($parent->parent_course,$parent->child_course); // this will do the unenrolments as well.
3156             }
3157             if ($showfeedback) {
3158                 notify("$strdeleted course_meta");
3159             }
3160         }
3161     }
3162
3163 /// Delete questions and question categories
3164     include_once($CFG->libdir.'/questionlib.php');
3165     question_delete_course($course, $showfeedback);
3166
3167 /// Delete all roles and overiddes in the course context (but keep the course context)
3168     if ($courseid != SITEID) {
3169         delete_context(CONTEXT_COURSE, $course->id);
3170     }
3171
3172     // fix for MDL-9016
3173     // clear the cache because the course context is deleted, and
3174     // we don't want to write assignment, overrides and context_rel table
3175     // with this old context id!
3176     get_context_instance('clearcache');
3177     return $result;
3178 }
3179
3180
3181 /**
3182  * This function will empty a course of USER data as much as
3183 /// possible. It will retain the activities and the structure
3184 /// of the course.
3185  *
3186  * @uses $USER
3187  * @uses $SESSION
3188  * @uses $CFG
3189  * @param object $data an object containing all the boolean settings and courseid
3190  * @param bool $showfeedback  if false then do it all silently
3191  * @return bool
3192  * @todo Finish documenting this function
3193  */
3194 function reset_course_userdata($data, $showfeedback=true) {
3195
3196     global $CFG, $USER, $SESSION;
3197
3198     $result = true;
3199
3200     $strdeleted = get_string('deleted');
3201
3202     // Look in every instance of every module for data to delete
3203
3204     if ($allmods = get_records('modules') ) {
3205         foreach ($allmods as $mod) {
3206             $modname = $mod->name;
3207             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3208             $moddeleteuserdata = $modname .'_delete_userdata';   // Function to delete user data
3209             if (file_exists($modfile)) {
3210                 @include_once($modfile);
3211                 if (function_exists($moddeleteuserdata)) {
3212                     $moddeleteuserdata($data, $showfeedback);
3213                 }
3214             }
3215         }
3216     } else {
3217         error('No modules are installed!');
3218     }
3219
3220     // Delete other stuff
3221     $coursecontext = get_context_instance(CONTEXT_COURSE, $data->courseid);
3222
3223     if (!empty($data->reset_students) or !empty($data->reset_teachers)) {
3224         $teachers     = array_keys(get_users_by_capability($coursecontext, 'moodle/course:update'));
3225         $participants = array_keys(get_users_by_capability($coursecontext, 'moodle/course:view'));
3226         $students     = array_diff($participants, $teachers);
3227
3228         if (!empty($data->reset_students)) {
3229             foreach ($students as $studentid) {
3230                 role_unassign(0, $studentid, 0, $coursecontext->id);
3231             }
3232             if ($showfeedback) {
3233                 notify($strdeleted .' '.get_string('students'), 'notifysuccess');
3234             }
3235
3236             /// Delete group members (but keep the groups) TODO:check.
3237             if ($groupids = groups_get_groups($data->courseid)) {
3238                 foreach ($groupids as $groupid) {
3239                     if (groups_remove_all_group_members($groupid)) {
3240                         if ($showfeedback) {
3241                             notify($strdeleted .' groups_members', 'notifysuccess');
3242                         }
3243                     } else {
3244                         $result = false;
3245                     }
3246                 }
3247             }
3248         }
3249
3250         if (!empty($data->reset_teachers)) {
3251             foreach ($teachers as $teacherid) {
3252                 role_unassign(0, $teacherid, 0, $coursecontext->id);
3253             }
3254             if ($showfeedback) {
3255                 notify($strdeleted .' '.get_string('teachers'), 'notifysuccess');
3256             }
3257         }
3258     }
3259
3260     if (!empty($data->reset_groups)) {
3261         if ($groupids = groups_get_groups($data->courseid)) {
3262             foreach ($groupids as $groupid) {
3263                 if (groups_delete_group($groupid)) {
3264                     if ($showfeedback) {
3265                         notify($strdeleted .' groups', 'notifysuccess');
3266                     }
3267                 } else {
3268                     $result = false;
3269                 }
3270             }
3271         }
3272     }
3273
3274     if (!empty($data->reset_events)) {
3275         if (delete_records('event', 'courseid', $data->courseid)) {
3276             if ($showfeedback) {
3277                 notify($strdeleted .' event', 'notifysuccess');
3278             }
3279         } else {
3280             $result = false;
3281         }
3282     }
3283
3284     if (!empty($data->reset_logs)) {
3285         if (delete_records('log', 'course', $data->courseid)) {
3286             if ($showfeedback) {
3287                 notify($strdeleted .' log', 'notifysuccess');
3288             }
3289         } else {
3290             $result = false;
3291         }
3292     }
3293
3294     // deletes all role assignments, and local override, these have no courseid in table and needs separate process
3295     $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
3296     delete_records('role_capabilities', 'contextid', $context->id);
3297
3298     return $result;
3299 }
3300
3301
3302 require_once($CFG->dirroot.'/group/lib.php');
3303 /*TODO: functions moved to /group/lib/legacylib.php
3304
3305 ismember
3306 add_user_to_group
3307 mygroupid
3308 groupmode
3309 set_current_group
3310 ... */
3311
3312
3313 function generate_email_processing_address($modid,$modargs) {
3314     global $CFG;
3315
3316     if (empty($CFG->siteidentifier)) {    // Unique site identification code
3317         set_config('siteidentifier', random_string(32));
3318     }
3319
3320     $header = $CFG->mailprefix . substr(base64_encode(pack('C',$modid)),0,2).$modargs;
3321     return $header . substr(md5($header.$CFG->siteidentifier),0,16).'@'.$CFG->maildomain;
3322 }
3323
3324
3325 function moodle_process_email($modargs,$body) {
3326     // the first char should be an unencoded letter. We'll take this as an action
3327     switch ($modargs{0}) {
3328         case 'B': { // bounce
3329             list(,$userid) = unpack('V',base64_decode(substr($modargs,1,8)));
3330             if ($user = get_record_select("user","id=$userid","id,email")) {
3331                 // check the half md5 of their email
3332                 $md5check = substr(md5($user->email),0,16);
3333                 if ($md5check == substr($modargs, -16)) {
3334                     set_bounce_count($user);
3335                 }
3336                 // else maybe they've already changed it?
3337             }
3338         }
3339         break;
3340         // maybe more later?
3341     }
3342 }
3343
3344 /// CORRESPONDENCE  ////////////////////////////////////////////////
3345
3346 /**
3347  * Send an email to a specified user
3348  *
3349  * @uses $CFG
3350  * @uses $FULLME
3351  * @uses SITEID
3352  * @param user $user  A {@link $USER} object
3353  * @param user $from A {@link $USER} object
3354  * @param string $subject plain text subject line of the email
3355  * @param string $messagetext plain text version of the message
3356  * @param string $messagehtml complete html version of the message (optional)
3357  * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
3358  * @param string $attachname the name of the file (extension indicates MIME)
3359  * @param bool $usetrueaddress determines whether $from email address should
3360  *          be sent out. Will be overruled by user profile setting for maildisplay
3361  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3362  *          was blocked by user and "false" if there was another sort of error.
3363  */
3364 function email_to_user($user, $from, $subject, $messagetext, $messagehtml='', $attachment='', $attachname='', $usetrueaddress=true, $replyto='', $replytoname='') {
3365
3366     global $CFG, $FULLME;
3367
3368     include_once($CFG->libdir .'/phpmailer/class.phpmailer.php');
3369
3370 /// We are going to use textlib services here
3371     $textlib = textlib_get_instance();
3372
3373     if (empty($user)) {
3374         return false;
3375     }
3376
3377     // skip mail to suspended users
3378     if (isset($user->auth) && $user->auth=='nologin') {
3379         return true;
3380     }
3381
3382     if (!empty($user->emailstop)) {
3383         return 'emailstop';
3384     }
3385
3386     if (over_bounce_threshold($user)) {
3387         error_log("User $user->id (".fullname($user).") is over bounce threshold! Not sending.");
3388         return false;
3389     }
3390
3391     $mail = new phpmailer;
3392
3393     $mail->Version = 'Moodle '. $CFG->version;           // mailer version
3394     $mail->PluginDir = $CFG->libdir .'/phpmailer/';      // plugin directory (eg smtp plugin)
3395
3396     $mail->CharSet = 'UTF-8';
3397
3398     if ($CFG->smtphosts == 'qmail') {
3399         $mail->IsQmail();                              // use Qmail system
3400
3401     } else if (empty($CFG->smtphosts)) {
3402         $mail->IsMail();                               // use PHP mail() = sendmail
3403
3404     } else {
3405         $mail->IsSMTP();                               // use SMTP directly
3406         if (!empty($CFG->debugsmtp)) {
3407             echo '<pre>' . "\n";
3408             $mail->SMTPDebug = true;
3409         }
3410         $mail->Host = $CFG->smtphosts;               // specify main and backup servers
3411
3412         if ($CFG->smtpuser) {                          // Use SMTP authentication
3413             $mail->SMTPAuth = true;
3414             $mail->Username = $CFG->smtpuser;
3415             $mail->Password = $CFG->smtppass;
3416         }
3417     }
3418
3419     $adminuser = get_admin();
3420
3421     // make up an email address for handling bounces
3422     if (!empty($CFG->handlebounces)) {
3423         $modargs = 'B'.base64_encode(pack('V',$user->id)).substr(md5($user->email),0,16);
3424         $mail->Sender = generate_email_processing_address(0,$modargs);
3425     }
3426     else {
3427         $mail->Sender   = $adminuser->email;
3428     }
3429
3430     if (is_string($from)) { // So we can pass whatever we want if there is need
3431         $mail->From     = $CFG->noreplyaddress;
3432         $mail->FromName = $from;
3433     } else if ($usetrueaddress and $from->maildisplay) {
3434         $mail->From     = $from->email;
3435         $mail->FromName = fullname($from);
3436     } else {
3437         $mail->From     = $CFG->noreplyaddress;
3438         $mail->FromName = fullname($from);
3439         if (empty($replyto)) {
3440             $mail->AddReplyTo($CFG->noreplyaddress,get_string('noreplyname'));
3441         }
3442     }
3443
3444     if (!empty($replyto)) {
3445         $mail->AddReplyTo($replyto,$replytoname);
3446     }
3447
3448     $mail->Subject = substr(stripslashes($subject), 0, 900);
3449
3450     $mail->AddAddress($user->email, fullname($user) );
3451
3452     $mail->WordWrap = 79;                               // set word wrap
3453
3454     if (!empty($from->customheaders)) {                 // Add custom headers
3455         if (is_array($from->customheaders)) {
3456             foreach ($from->customheaders as $customheader) {
3457                 $mail->AddCustomHeader($customheader);
3458             }
3459         } else {
3460             $mail->AddCustomHeader($from->customheaders);
3461         }
3462     }
3463
3464     if (!empty($from->priority)) {
3465         $mail->Priority = $from->priority;
3466     }
3467
3468     if ($messagehtml && $user->mailformat == 1) { // Don't ever send HTML to users who don't want it
3469         $mail->IsHTML(true);
3470         $mail->Encoding = 'quoted-printable';           // Encoding to use
3471         $mail->Body    =  $messagehtml;
3472         $mail->AltBody =  "\n$messagetext\n";
3473     } else {
3474         $mail->IsHTML(false);
3475         $mail->Body =  "\n$messagetext\n";
3476     }
3477
3478     if ($attachment && $attachname) {
3479         if (ereg( "\\.\\." ,$attachment )) {    // Security check for ".." in dir path
3480             $mail->AddAddress($adminuser->email, fullname($adminuser) );
3481             $mail->AddStringAttachment('Error in attachment.  User attempted to attach a filename with a unsafe name.', 'error.txt', '8bit', 'text/plain');
3482         } else {
3483             require_once($CFG->libdir.'/filelib.php');
3484             $mimetype = mimeinfo('type', $attachname);
3485             $mail->AddAttachment($CFG->dataroot .'/'. $attachment, $attachname, 'base64', $mimetype);
3486         }
3487     }
3488
3489
3490
3491 /// If we are running under Unicode and sitemailcharset or allowusermailcharset are set, convert the email
3492 /// encoding to the specified one
3493     if ((!empty($CFG->sitemailcharset) || !empty($CFG->allowusermailcharset))) {
3494     /// Set it to site mail charset
3495         $charset = $CFG->sitemailcharset;
3496     /// Overwrite it with the user mail charset
3497         if (!empty($CFG->allowusermailcharset)) {
3498             if ($useremailcharset = get_user_preferences('mailcharset', '0', $user->id)) {
3499                 $charset = $useremailcharset;
3500             }
3501         }
3502     /// If it has changed, convert all the necessary strings
3503         $charsets = get_list_of_charsets();
3504         unset($charsets['UTF-8']);
3505         if (in_array($charset, $charsets)) {
3506         /// Save the new mail charset
3507             $mail->CharSet = $charset;
3508         /// And convert some strings
3509             $mail->FromName = $textlib->convert($mail->FromName, 'utf-8', $mail->CharSet); //From Name
3510             foreach ($mail->ReplyTo as $key => $rt) {                                      //ReplyTo Names
3511                 $mail->ReplyTo[$key][1] = $textlib->convert($rt, 'utf-8', $mail->CharSet);
3512             }
3513             $mail->Subject = $textlib->convert($mail->Subject, 'utf-8', $mail->CharSet);   //Subject
3514             foreach ($mail->to as $key => $to) {
3515                 $mail->to[$key][1] = $textlib->convert($to, 'utf-8', $mail->CharSet);      //To Names
3516             }
3517             $mail->Body = $textlib->convert($mail->Body, 'utf-8', $mail->CharSet);         //Body
3518             $mail->AltBody = $textlib->convert($mail->AltBody, 'utf-8', $mail->CharSet);   //Subject
3519         }
3520     }
3521
3522     if ($mail->Send()) {
3523         set_send_count($user);
3524         $mail->IsSMTP();                               // use SMTP directly
3525         if (!empty($CFG->debugsmtp)) {
3526             echo '</pre>';
3527         }
3528         return true;
3529     } else {
3530         mtrace('ERROR: '. $mail->ErrorInfo);
3531         add_to_log(SITEID, 'library', 'mailer', $FULLME, 'ERROR: '. $mail->ErrorInfo);
3532         if (!empty($CFG->debugsmtp)) {
3533             echo '</pre>';
3534         }
3535         return false;
3536     }
3537 }
3538
3539 /**
3540  * Sets specified user's password and send the new password to the user via email.
3541  *
3542  * @uses $CFG
3543  * @param user $user A {@link $USER} object
3544  * @return boolean|string Returns "true" if mail was sent OK, "emailstop" if email
3545  *          was blocked by user and "false" if there was another sort of error.
3546  */
3547 function setnew_password_and_mail($user) {
3548
3549     global $CFG;
3550
3551     $site  = get_site();
3552     $from = get_admin();
3553
3554     $newpassword = generate_password();
3555
3556     if (! set_field('user', 'password', md5($newpassword), 'id', $user->id) ) {
3557         trigger_error('Could not set user password!');
3558         return false;
3559     }
3560
3561     $a = new object();
3562     $a->firstname   = $user->firstname;
3563     $a->sitename    = format_string($site->fullname);
3564     $a->username    = $user->username;
3565     $a->newpassword = $newpassword;
3566     $a->link        = $CFG->wwwroot .'/login/';
3567     $a->signoff     = fullname($from, true).' ('. $from->email .')';
3568
3569     $message = get_string('newusernewpasswordtext', '', $a);
3570
3571     $subject  = format_string($site->fullname) .': '. get_string('newusernewpasswordsubj');
3572
3573     return email_to_user($user, $from, $subject, $message);
3574
3575 }
3576
3577 /**
3578  * Resets specified user's password and send the new password to the user via email.
3579  *
3580  * @uses $CFG
3581  * @param user $user A {@link $USER} object
3582  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3583  *          was blocked by user and "false" if there was another sort of error.
3584  */
3585 function reset_password_and_mail($user) {
3586
3587     global $CFG;
3588
3589     $site  = get_site();
3590     $from = get_admin();
3591
3592     $userauth = get_auth_plugin($user->auth);
3593     if (!$userauth->can_reset_password() or !is_enabled_auth($user->auth)) {
3594         trigger_error("Attempt to reset user password for user $user->username with Auth $user->auth.");
3595         return false;
3596     }
3597
3598     $newpassword = generate_password();
3599
3600     if (!$userauth->user_update_password(addslashes_recursive($user), addslashes($newpassword))) {
3601         error("Could not set user password!");
3602     }
3603
3604     $a = new object();
3605     $a->firstname = $user->firstname;
3606     $a->sitename = format_string($site->fullname);
3607     $a->username = $user->username;
3608     $a->newpassword = $newpassword;
3609     $a->link = $CFG->httpswwwroot .'/login/change_password.php';
3610     $a->signoff = fullname($from, true).' ('. $from->email .')';
3611
3612     $message = get_string('newpasswordtext', '', $a);
3613
3614     $subject  = format_string($site->fullname) .': '. get_string('changedpassword');
3615
3616     return email_to_user($user, $from, $subject, $message);
3617
3618 }
3619
3620 /**
3621  * Send email to specified user with confirmation text and activation link.
3622  *
3623  * @uses $CFG
3624  * @param user $user A {@link $USER} object
3625  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3626  *          was blocked by user and "false" if there was another sort of error.
3627  */
3628  function send_confirmation_email($user) {
3629
3630     global $CFG;
3631
3632     $site = get_site();
3633     $from = get_admin();
3634
3635     $data = new object();
3636     $data->firstname = fullname($user);
3637     $data->sitename = format_string($site->fullname);
3638     $data->admin = fullname($from) .' ('. $from->email .')';
3639
3640     $subject = get_string('emailconfirmationsubject', '', format_string($site->fullname));
3641
3642     $data->link = $CFG->wwwroot .'/login/confirm.php?data='. $user->secret .'/'. urlencode($user->username);
3643     $message     = get_string('emailconfirmation', '', $data);
3644     $messagehtml = text_to_html(get_string('emailconfirmation', '', $data), false, false, true);
3645
3646     $user->mailformat = 1;  // Always send HTML version as well
3647
3648     return email_to_user($user, $from, $subject, $message, $messagehtml);
3649
3650 }
3651
3652 /**
3653  * send_password_change_confirmation_email.
3654  *
3655  * @uses $CFG
3656  * @param user $user A {@link $USER} object
3657  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3658  *          was blocked by user and "false" if there was another sort of error.
3659  */
3660 function send_password_change_confirmation_email($user) {
3661
3662     global $CFG;
3663
3664     $site = get_site();
3665     $from = get_admin();
3666
3667     $data = new object();
3668     $data->firstname = $user->firstname;
3669     $data->sitename = format_string($site->fullname);
3670     $data->link = $CFG->httpswwwroot .'/login/forgot_password.php?p='. $user->secret .'&s='. urlencode($user->username);
3671     $data->admin = fullname($from).' ('. $from->email .')';
3672
3673     $message = get_string('emailpasswordconfirmation', '', $data);
3674     $subject = get_string('emailpasswordconfirmationsubject', '', format_string($site->fullname));
3675
3676     return email_to_user($user, $from, $subject, $message);
3677
3678 }
3679
3680 /**
3681  * send_password_change_info.
3682  *
3683  * @uses $CFG
3684  * @param user $user A {@link $USER} object
3685  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3686  *          was blocked by user and "false" if there was another sort of error.
3687  */
3688 function send_password_change_info($user) {
3689
3690     global $CFG;
3691
3692     $site = get_site();
3693     $from = get_admin();
3694     $systemcontext = get_context_instance(CONTEXT_SYSTEM);
3695
3696     $data = new object();
3697     $data->firstname = $user->firstname;
3698     $data->sitename = format_string($site->fullname);
3699     $data->admin = fullname($from).' ('. $from->email .')';
3700
3701     $userauth = get_auth_plugin($user->auth);
3702
3703     if (!is_enabled_auth($user->auth) or $user->auth == 'nologin') {
3704         $message = get_string('emailpasswordchangeinfodisabled', '', $data);
3705         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3706         return email_to_user($user, $from, $subject, $message);
3707     }
3708
3709     if ($userauth->can_change_password() and $userauth->change_password_url()) {
3710         // we have some external url for password changing
3711         $data->link .= $userauth->change_password_url();
3712
3713     } else {
3714         //no way to change password, sorry
3715         $data->link = '';
3716     }
3717
3718     if (!empty($data->link) and has_capability('moodle/user:changeownpassword', $systemcontext, $user->id)) {
3719         $message = get_string('emailpasswordchangeinfo', '', $data);
3720         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3721     } else {
3722         $message = get_string('emailpasswordchangeinfofail', '', $data);
3723         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3724     }
3725
3726     return email_to_user($user, $from, $subject, $message);
3727
3728 }
3729
3730 /**
3731  * Check that an email is allowed.  It returns an error message if there
3732  * was a problem.
3733  *
3734  * @uses $CFG
3735  * @param  string $email Content of email
3736  * @return string|false
3737  */
3738 function email_is_not_allowed($email) {
3739
3740     global $CFG;
3741
3742     if (!empty($CFG->allowemailaddresses)) {
3743         $allowed = explode(' ', $CFG->allowemailaddresses);
3744         foreach ($allowed as $allowedpattern) {
3745             $allowedpattern = trim($allowedpattern);
3746             if (!$allowedpattern) {
3747                 continue;
3748             }
3749             if (strpos(strrev($email), strrev('@'.$allowedpattern)) === 0) { // Match!   (bug 5250)
3750                 return false;
3751             }
3752         }
3753         return get_string('emailonlyallowed', '', $CFG->allowemailaddresses);
3754
3755     } else if (!empty($CFG->denyemailaddresses)) {
3756         $denied = explode(' ', $CFG->denyemailaddresses);
3757         foreach ($denied as $deniedpattern) {
3758             $deniedpattern = trim($deniedpattern);
3759             if (!$deniedpattern) {
3760                 continue;
3761             }
3762             if (strpos(strrev($email), strrev('@'.$deniedpattern)) === 0) { // Match!   (bug 5250)
3763                 return get_string('emailnotallowed', '', $CFG->denyemailaddresses);
3764             }
3765         }
3766     }
3767
3768     return false;
3769 }
3770
3771 function email_welcome_message_to_user($course, $user=NULL) {
3772     global $CFG, $USER;
3773
3774     if (empty($user)) {
3775         if (!isloggedin()) {
3776             return false;
3777         }
3778         $user = $USER;
3779     }
3780
3781     if (!empty($course->welcomemessage)) {
3782         $subject = get_string('welcometocourse', '', format_string($course->fullname));
3783
3784         $a->coursename = $course->fullname;
3785         $a->profileurl = "$CFG->wwwroot/user/view.php?id=$USER->id&course=$course->id";
3786         //$message = get_string("welcometocoursetext", "", $a);
3787         $message = $course->welcomemessage;
3788
3789         if (! $teacher = get_teacher($course->id)) {
3790             $teacher = get_admin();
3791         }
3792         email_to_user($user, $teacher, $subject, $message);
3793     }
3794 }
3795
3796 /// FILE HANDLING  /////////////////////////////////////////////
3797
3798
3799 /**
3800  * Makes an upload directory for a particular module.
3801  *
3802  * @uses $CFG
3803  * @param int $courseid The id of the course in question - maps to id field of 'course' table.
3804  * @return string|false Returns full path to directory if successful, false if not
3805  */
3806 function make_mod_upload_directory($courseid) {
3807     global $CFG;
3808
3809     if (! $moddata = make_upload_directory($courseid .'/'. $CFG->moddata)) {
3810         return false;
3811     }
3812
3813     $strreadme = get_string('readme');
3814
3815     if (file_exists($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt')) {
3816         copy($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
3817     } else {
3818         copy($CFG->dirroot .'/lang/en_utf8/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
3819     }
3820     return $moddata;
3821 }
3822
3823 /**
3824  * Returns current name of file on disk if it exists.
3825  *
3826  * @param string $newfile File to be verified
3827  * @return string Current name of file on disk if true
3828  */
3829 function valid_uploaded_file($newfile) {
3830     if (empty($newfile)) {
3831         return '';
3832     }
3833     if (is_uploaded_file($newfile['tmp_name']) and $newfile['size'] > 0) {
3834         return $newfile['tmp_name'];
3835     } else {
3836         return '';
3837     }
3838 }
3839
3840 /**
3841  * Returns the maximum size for uploading files.
3842  *
3843  * There are seven possible upload limits:
3844  * 1. in Apache using LimitRequestBody (no way of checking or changing this)
3845  * 2. in php.ini for 'upload_max_filesize' (can not be changed inside PHP)
3846  * 3. in .htaccess for 'upload_max_filesize' (can not be changed inside PHP)
3847  * 4. in php.ini for 'post_max_size' (can not be changed inside PHP)
3848  * 5. by the Moodle admin in $CFG->maxbytes
3849  * 6. by the teacher in the current course $course->maxbytes
3850  * 7. by the teacher for the current module, eg $assignment->maxbytes
3851  *
3852  * These last two are passed to this function as arguments (in bytes).
3853  * Anything defined as 0 is ignored.
3854  * The smallest of all the non-zero numbers is returned.
3855  *
3856  * @param int $sizebytes ?
3857  * @param int $coursebytes Current course $course->maxbytes (in bytes)
3858  * @param int $modulebytes Current module ->maxbytes (in bytes)
3859  * @return int The maximum size for uploading files.
3860  * @todo Finish documenting this function
3861  */
3862 function get_max_upload_file_size($sitebytes=0, $coursebytes=0, $modulebytes=0) {
3863
3864     if (! $filesize = ini_get('upload_max_filesize')) {
3865         $filesize = '5M';
3866     }
3867     $minimumsize = get_real_size($filesize);
3868
3869     if ($postsize = ini_get('post_max_size')) {
3870         $postsize = get_real_size($postsize);
3871         if ($postsize < $minimumsize) {
3872             $minimumsize = $postsize;
3873         }
3874     }
3875
3876     if ($sitebytes and $sitebytes < $minimumsize) {
3877         $minimumsize = $sitebytes;
3878     }
3879
3880     if ($coursebytes and $coursebytes < $minimumsize) {
3881         $minimumsize = $coursebytes;
3882     }
3883
3884     if ($modulebytes and $modulebytes < $minimumsize) {
3885         $minimumsize = $modulebytes;
3886     }
3887
3888     return $minimumsize;
3889 }
3890
3891 /**
3892  * Related to {@link get_max_upload_file_size()} - this function returns an
3893  * array of possible sizes in an array, translated to the
3894  * local language.
3895  *
3896  * @uses SORT_NUMERIC
3897  * @param int $sizebytes ?
3898  * @param int $coursebytes Current course $course->maxbytes (in bytes)
3899  * @param int $modulebytes Current module ->maxbytes (in bytes)
3900  * @return int
3901  * @todo Finish documenting this function
3902  */
3903 function get_max_upload_sizes($sitebytes=0, $coursebytes=0, $modulebytes=0) {
3904     global $CFG;
3905
3906     if (!$maxsize = get_max_upload_file_size($sitebytes, $coursebytes, $modulebytes)) {
3907         return array();
3908     }
3909
3910     $filesize[$maxsize] = display_size($maxsize);
3911
3912     $sizelist = array(10240, 51200, 102400, 512000, 1048576, 2097152,
3913                       5242880, 10485760, 20971520, 52428800, 104857600);
3914
3915     // Allow maxbytes to be selected if it falls outside the above boundaries
3916     if( isset($CFG->maxbytes) && !in_array($CFG->maxbytes, $sizelist) ){
3917             $sizelist[] = $CFG->maxbytes;
3918     }
3919
3920     foreach ($sizelist as $sizebytes) {
3921        if ($sizebytes < $maxsize) {
3922            $filesize[$sizebytes] = display_size($sizebytes);
3923        }
3924     }
3925
3926     krsort($filesize, SORT_NUMERIC);
3927
3928     return $filesize;
3929 }
3930
3931 /**
3932  * If there has been an error uploading a file, print the appropriate error message
3933  * Numerical constants used as constant definitions not added until PHP version 4.2.0
3934  *
3935  * $filearray is a 1-dimensional sub-array of the $_FILES array
3936  * eg $filearray = $_FILES['userfile1']
3937  * If left empty then the first element of the $_FILES array will be used
3938  *
3939  * @uses $_FILES
3940  * @param array $filearray  A 1-dimensional sub-array of the $_FILES array
3941  * @param bool $returnerror If true then a string error message will be returned. Otherwise the user will be notified of the error in a notify() call.
3942  * @return bool|string
3943  */
3944 function print_file_upload_error($filearray = '', $returnerror = false) {
3945
3946     if ($filearray == '' or !isset($filearray['error'])) {
3947
3948         if (empty($_FILES)) return false;
3949
3950         $files = $_FILES; /// so we don't mess up the _FILES array for subsequent code
3951         $filearray = array_shift($files); /// use first element of array
3952     }
3953
3954     switch ($filearray['error']) {
3955
3956         case 0: // UPLOAD_ERR_OK
3957             if ($filearray['size'] > 0) {
3958                 $errmessage = get_string('uploadproblem', $filearray['name']);
3959             } else {
3960                 $errmessage = get_string('uploadnofilefound'); /// probably a dud file name
3961             }
3962             break;
3963
3964         case 1: // UPLOAD_ERR_INI_SIZE
3965             $errmessage = get_string('uploadserverlimit');
3966             break;
3967
3968         case 2: // UPLOAD_ERR_FORM_SIZE
3969             $errmessage = get_string('uploadformlimit');
3970             break;
3971
3972         case 3: // UPLOAD_ERR_PARTIAL
3973             $errmessage = get_string('uploadpartialfile');
3974             break;
3975
3976         case 4: // UPLOAD_ERR_NO_FILE
3977             $errmessage = get_string('uploadnofilefound');
3978             break;
3979
3980         default:
3981             $errmessage = get_string('uploadproblem', $filearray['name']);
3982     }
3983
3984     if ($returnerror) {
3985         return $errmessage;
3986     } else {
3987         notify($errmessage);
3988         return true;
3989     }
3990
3991 }
3992
3993 /**
3994  * handy function to loop through an array of files and resolve any filename conflicts
3995  * both in the array of filenames and for what is already on disk.
3996  * not really compatible with the similar function in uploadlib.php
3997  * but this could be used for files/index.php for moving files around.
3998  */
3999
4000 function resolve_filename_collisions($destination,$files,$format='%s_%d.%s') {
4001     foreach ($files as $k => $f) {
4002         if (check_potential_filename($destination,$f,$files)) {
4003             $bits = explode('.', $f);
4004             for ($i = 1; true; $i++) {
4005                 $try = sprintf($format, $bits[0], $i, $bits[1]);
4006                 if (!check_potential_filename($destination,$try,$files)) {
4007                     $files[$k] = $try;
4008                     break;
4009                 }
4010             }
4011         }
4012     }
4013     return $files;
4014 }
4015
4016 /**
4017  * @used by resolve_filename_collisions
4018  */
4019 function check_potential_filename($destination,$filename,$files) {
4020     if (file_exists($destination.'/'.$filename)) {
4021         return true;
4022     }
4023     if (count(array_keys($files,$filename)) > 1) {
4024         return true;
4025     }
4026     return false;
4027 }
4028
4029
4030 /**
4031  * Returns an array with all the filenames in
4032  * all subdirectories, relative to the given rootdir.
4033  * If excludefile is defined, then that file/directory is ignored
4034  * If getdirs is true, then (sub)directories are included in the output
4035  * If getfiles is true, then files are included in the output
4036  * (at least one of these must be true!)
4037  *
4038  * @param string $rootdir  ?
4039  * @param string $excludefile  If defined then the specified file/directory is ignored
4040  * @param bool $descend  ?
4041  * @param bool $getdirs  If true then (sub)directories are included in the output
4042  * @param bool $getfiles  If true then files are included in the output
4043  * @return array An array with all the filenames in
4044  * all subdirectories, relative to the given rootdir
4045  * @todo Finish documenting this function. Add examples of $excludefile usage.
4046  */
4047 function get_directory_list($rootdir, $excludefiles='', $descend=true, $getdirs=false, $getfiles=true) {
4048
4049     $dirs = array();
4050
4051     if (!$getdirs and !$getfiles) {   // Nothing to show
4052         return $dirs;
4053     }
4054
4055     if (!is_dir($rootdir)) {          // Must be a directory
4056         return $dirs;
4057     }
4058
4059     if (!$dir = opendir($rootdir)) {  // Can't open it for some reason
4060         return $dirs;
4061     }
4062
4063     if (!is_array($excludefiles)) {
4064         $excludefiles = array($excludefiles);
4065     }
4066
4067     while (false !== ($file = readdir($dir))) {
4068         $firstchar = substr($file, 0, 1);
4069         if ($firstchar == '.' or $file == 'CVS' or in_array($file, $excludefiles)) {
4070             continue;
4071         }
4072         $fullfile = $rootdir .'/'. $file;
4073         if (filetype($fullfile) == 'dir') {
4074             if ($getdirs) {
4075                 $dirs[] = $file;
4076             }
4077             if ($descend) {
4078                 $subdirs = get_directory_list($fullfile, $excludefiles, $descend, $getdirs, $getfiles);
4079                 foreach ($subdirs as $subdir) {
4080                     $dirs[] = $file .'/'. $subdir;
4081                 }
4082             }
4083         } else if ($getfiles) {
4084             $dirs[] = $file;
4085         }
4086     }
4087     closedir($dir);
4088
4089     asort($dirs);
4090
4091     return $dirs;
4092 }
4093
4094
4095 /**
4096  * Adds up all the files in a directory and works out the size.
4097  *
4098  * @param string $rootdir  ?
4099  * @param string $excludefile  ?
4100  * @return array
4101  * @todo Finish documenting this function
4102  */
4103 function get_directory_size($rootdir, $excludefile='') {
4104
4105     global $CFG;
4106
4107     // do it this way if we can, it's much faster
4108     if (!empty($CFG->pathtodu) && is_executable(trim($CFG->pathtodu))) {
4109         $command = trim($CFG->pathtodu).' -sk --apparent-size '.escapeshellarg($rootdir);
4110         $output = null;
4111         $return = null;
4112         exec($command,$output,$return);
4113         if (is_array($output)) {
4114             return get_real_size(intval($output[0]).'k'); // we told it to return k.
4115         }
4116     }
4117
4118     if (!is_dir($rootdir)) {          // Must be a directory
4119         return 0;
4120     }
4121
4122     if (!$dir = @opendir($rootdir)) {  // Can't open it for some reason
4123         return 0;
4124     }
4125
4126     $size = 0;
4127
4128     while (false !== ($file = readdir($dir))) {
4129         $firstchar = substr($file, 0, 1);
4130         if ($firstchar == '.' or $file == 'CVS' or $file == $excludefile) {
4131             continue;
4132         }
4133         $fullfile = $rootdir .'/'. $file;
4134         if (filetype($fullfile) == 'dir') {
4135             $size += get_directory_size($fullfile, $excludefile);
4136         } else {
4137             $size += filesize($fullfile);
4138         }
4139     }
4140     closedir($dir);
4141
4142     return $size;
4143 }
4144
4145 /**
4146  * Converts bytes into display form
4147  *
4148  * @param string $size  ?
4149  * @return string
4150  * @staticvar string $gb Localized string for size in gigabytes
4151  * @staticvar string $mb Localized string for size in megabytes
4152  * @staticvar string $kb Localized string for size in kilobytes
4153  * @staticvar string $b Localized string for size in bytes
4154  * @todo Finish documenting this function. Verify return type.
4155  */
4156 function display_size($size) {
4157
4158     static $gb, $mb, $kb, $b;
4159
4160     if (empty($gb)) {
4161         $gb = get_string('sizegb');
4162         $mb = get_string('sizemb');
4163         $kb = get_string('sizekb');
4164         $b  = get_string('sizeb');
4165     }
4166
4167     if ($size >= 1073741824) {
4168         $size = round($size / 1073741824 * 10) / 10 . $gb;
4169     } else if ($size >= 1048576) {
4170         $size = round($size / 1048576 * 10) / 10 . $mb;
4171     } else if ($size >= 1024) {
4172         $size = round($size / 1024 * 10) / 10 . $kb;
4173     } else {
4174         $size = $size .' '. $b;
4175     }
4176     return $size;
4177 }
4178
4179 /**
4180  * Cleans a given filename by removing suspicious or troublesome characters
4181  * Only these are allowed: alphanumeric _ - .
4182  * Unicode characters can be enabled by setting $CFG->unicodecleanfilename = true in config.php
4183  *
4184  * WARNING: unicode characters may not be compatible with zip compression in backup/restore,
4185  *          because native zip binaries do weird character conversions. Use PHP zipping instead.
4186  *
4187  * @param string $string  file name
4188  * @return string cleaned file name
4189  */
4190 function clean_filename($string) {
4191     global $CFG;
4192     if (empty($CFG->unicodecleanfilename)) {
4193         $textlib = textlib_get_instance();
4194         $string = $textlib->specialtoascii($string);
4195         $string = preg_replace('/[^\.a-zA-Z\d\_-]/','_', $string ); // only allowed chars
4196     } else {
4197         //clean only ascii range
4198         $string = preg_replace("/[\\000-\\x2c\\x2f\\x3a-\\x40\\x5b-\\x5e\\x60\\x7b-\\177]/s", '_', $string);
4199     }
4200     $string = preg_replace("/_+/", '_', $string);
4201     $string = preg_replace("/\.\.+/", '.', $string);
4202     return $string;
4203 }
4204
4205
4206 /// STRING TRANSLATION  ////////////////////////////////////////
4207
4208 /**
4209  * Returns the code for the current language
4210  *
4211  * @uses $CFG
4212  * @param $USER
4213  * @param $SESSION
4214  * @return string
4215  */
4216 function current_language() {
4217     global $CFG, $USER, $SESSION, $COURSE;
4218
4219     if (!empty($COURSE->id) and $COURSE->id != SITEID and !empty($COURSE->lang)) {    // Course language can override all other settings for this page
4220         $return = $COURSE->lang;
4221
4222     } else if (!empty($SESSION->lang)) {    // Session language can override other settings
4223         $return = $SESSION->lang;
4224
4225     } else if (!empty($USER->lang)) {
4226         $return = $USER->lang;
4227
4228     } else {
4229         $return = $CFG->lang;
4230     }
4231
4232     if ($return == 'en') {
4233         $return = 'en_utf8';
4234     }
4235
4236     return $return;
4237 }
4238
4239 /**
4240  * Prints out a translated string.
4241  *
4242  * Prints out a translated string using the return value from the {@link get_string()} function.
4243  *
4244  * Example usage of this function when the string is in the moodle.php file:<br/>
4245  * <code>
4246  * echo '<strong>';
4247  * print_string('wordforstudent');
4248  * echo '</strong>';
4249  * </code>
4250  *
4251  * Example usage of this function when the string is not in the moodle.php file:<br/>
4252  * <code>
4253  * echo '<h1>';
4254  * print_string('typecourse', 'calendar');
4255  * echo '</h1>';
4256  * </code>
4257  *
4258  * @param string $identifier The key identifier for the localized string
4259  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4260  * @param mixed $a An object, string or number that can be used
4261  * within translation strings
4262  */
4263 function print_string($identifier, $module='', $a=NULL) {
4264     echo get_string($identifier, $module, $a);
4265 }
4266
4267 /**
4268  * fix up the optional data in get_string()/print_string() etc
4269  * ensure possible sprintf() format characters are escaped correctly
4270  * needs to handle arbitrary strings and objects
4271  * @param mixed $a An object, string or number that can be used
4272  * @return mixed the supplied parameter 'cleaned'
4273  */
4274 function clean_getstring_data( $a ) {
4275     if (is_string($a)) {
4276         return str_replace( '%','%%',$a );
4277     }
4278     elseif (is_object($a)) {
4279         $a_vars = get_object_vars( $a );
4280         $new_a_vars = array();
4281         foreach ($a_vars as $fname => $a_var) {
4282             $new_a_vars[$fname] = clean_getstring_data( $a_var );
4283         }
4284         return (object)$new_a_vars;
4285     }
4286     else {
4287         return $a;
4288     }
4289 }
4290
4291 /**
4292  * @return array places to look for lang strings based on the prefix to the
4293  * module name. For example qtype_ in question/type. Used by get_string and
4294  * help.php.
4295  */
4296 function places_to_search_for_lang_strings() {
4297     global $CFG;
4298
4299     return array(
4300         '__exceptions' => array('moodle', 'langconfig'),
4301         'assignment_' => array('mod/assignment/type'),
4302         'auth_' => array('auth'),
4303         'block_' => array('blocks'),
4304         'datafield_' => array('mod/data/field'),
4305         'datapreset_' => array('mod/data/preset'),
4306         'enrol_' => array('enrol'),
4307         'format_' => array('course/format'),
4308         'qtype_' => array('question/type'),
4309         'report_' => array($CFG->admin.'/report', 'course/report', 'mod/quiz/report'),
4310         'resource_' => array('mod/resource/type'),
4311         '' => array('mod')
4312     );
4313 }
4314
4315 /**
4316  * Returns a localized string.
4317  *
4318  * Returns the translated string specified by $identifier as
4319  * for $module.  Uses the same format files as STphp.
4320  * $a is an object, string or number that can be used
4321  * within translation strings
4322  *
4323  * eg "hello \$a->firstname \$a->lastname"
4324  * or "hello \$a"
4325  *
4326  * If you would like to directly echo the localized string use
4327  * the function {@link print_string()}
4328  *
4329  * Example usage of this function involves finding the string you would
4330  * like a local equivalent of and using its identifier and module information
4331  * to retrive it.<br/>
4332  * If you open moodle/lang/en/moodle.php and look near line 1031
4333  * you will find a string to prompt a user for their word for student
4334  * <code>
4335  * $string['wordforstudent'] = 'Your word for Student';
4336  * </code>
4337  * So if you want to display the string 'Your word for student'
4338  * in any language that supports it on your site
4339  * you just need to use the identifier 'wordforstudent'
4340  * <code>
4341  * $mystring = '<strong>'. get_string('wordforstudent') .'</strong>';
4342 or
4343  * </code>
4344  * If the string you want is in another file you'd take a slightly
4345  * different approach. Looking in moodle/lang/en/calendar.php you find
4346  * around line 75:
4347  * <code>
4348  * $string['typecourse'] = 'Course event';
4349  * </code>
4350  * If you want to display the string "Course event" in any language
4351  * supported you would use the identifier 'typecourse' and the module 'calendar'
4352  * (because it is in the file calendar.php):
4353  * <code>
4354  * $mystring = '<h1>'. get_string('typecourse', 'calendar') .'</h1>';
4355  * </code>
4356  *
4357  * As a last resort, should the identifier fail to map to a string
4358  * the returned string will be [[ $identifier ]]
4359  *
4360  * @uses $CFG
4361  * @param string $identifier The key identifier for the localized string
4362  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4363  * @param mixed $a An object, string or number that can be used
4364  * within translation strings
4365  * @param array $extralocations An array of strings with other locations to look for string files
4366  * @return string The localized string.
4367  */
4368 function get_string($identifier, $module='', $a=NULL, $extralocations=NULL) {
4369
4370     global $CFG;
4371
4372 /// originally these special strings were stored in moodle.php now we are only in langconfig.php
4373     $langconfigstrs = array('alphabet', 'backupnameformat', 'firstdayofweek', 'locale',
4374                             'localewin', 'localewincharset', 'oldcharset',
4375                             'parentlanguage', 'strftimedate', 'strftimedateshort', 'strftimedatetime',
4376                             'strftimedaydate', 'strftimedaydatetime', 'strftimedayshort', 'strftimedaytime',
4377                             'strftimemonthyear', 'strftimerecent', 'strftimerecentfull', 'strftimetime',
4378                             'thischarset', 'thisdirection', 'thislanguage');
4379
4380     $filetocheck = 'langconfig.php';
4381     $defaultlang = 'en_utf8';
4382     if (in_array($identifier, $langconfigstrs)) {
4383         $module = 'langconfig';  //This strings are under langconfig.php for 1.6 lang packs
4384     }
4385
4386     $lang = current_language();
4387
4388     if ($module == '') {
4389         $module = 'moodle';
4390     }
4391
4392     // if $a happens to have % in it, double it so sprintf() doesn't break
4393     if ($a) {
4394         $a = clean_getstring_data( $a );
4395     }
4396
4397 /// Define the two or three major locations of language strings for this module
4398     $locations = array();
4399
4400     if (!empty($extralocations)) {   // Calling code has a good idea where to look
4401         if (is_array($extralocations)) {
4402             $locations += $extralocations;
4403         } else if (is_string($extralocations)) {
4404             $locations[] = $extralocations;
4405         } else {
4406             debugging('Bad lang path provided');
4407         }
4408     }
4409
4410     if (isset($CFG->running_installer)) {
4411         $module = 'installer';
4412         $filetocheck = 'installer.php';
4413         $locations += array( $CFG->dirroot.'/install/lang/', $CFG->dataroot.'/lang/',  $CFG->dirroot.'/lang/' );
4414         $defaultlang = 'en_utf8';
4415     } else {
4416         $locations += array( $CFG->dataroot.'/lang/',  $CFG->dirroot.'/lang/' );
4417     }
4418
4419 /// Add extra places to look for strings for particular plugin types.
4420     $rules = places_to_search_for_lang_strings();
4421     $exceptions = $rules['__exceptions'];
4422     unset($rules['__exceptions']);
4423
4424     if (!in_array($module, $exceptions)) {
4425         $dividerpos = strpos($module, '_');
4426         if ($dividerpos === false) {
4427             $type = '';
4428             $plugin = $module;
4429         } else {
4430             $type = substr($module, 0, $dividerpos + 1);
4431             $plugin = substr($module, $dividerpos + 1);
4432         }
4433         if (!empty($rules[$type])) {
4434             foreach ($rules[$type] as $location) {
4435                 $locations[] = $CFG->dirroot . "/$location/$plugin/lang/";
4436             }
4437         }
4438     }
4439
4440 /// First check all the normal locations for the string in the current language
4441     $resultstring = '';
4442     foreach ($locations as $location) {
4443         $locallangfile = $location.$lang.'_local'.'/'.$module.'.php';    //first, see if there's a local file
4444         if (file_exists($locallangfile)) {
4445             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4446                 eval($result);
4447                 return $resultstring;
4448             }
4449         }
4450         //if local directory not found, or particular string does not exist in local direcotry
4451         $langfile = $location.$lang.'/'.$module.'.php';
4452         if (file_exists($langfile)) {
4453             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4454                 eval($result);
4455                 return $resultstring;
4456             }
4457         }
4458     }
4459
4460 /// If the preferred language was English (utf8) we can abort now
4461 /// saving some checks beacuse it's the only "root" lang
4462     if ($lang == 'en_utf8') {
4463         return '[['. $identifier .']]';
4464     }
4465
4466 /// Is a parent language defined?  If so, try to find this string in a parent language file
4467
4468     foreach ($locations as $location) {
4469         $langfile = $location.$lang.'/'.$filetocheck;
4470         if (file_exists($langfile)) {
4471             if ($result = get_string_from_file('parentlanguage', $langfile, "\$parentlang")) {
4472                 eval($result);
4473                 if (!empty($parentlang)) {   // found it!
4474
4475                     //first, see if there's a local file for parent
4476                     $locallangfile = $location.$parentlang.'_local'.'/'.$module.'.php';
4477                     if (file_exists($locallangfile)) {
4478                         if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4479                             eval($result);
4480                             return $resultstring;
4481                         }
4482                     }
4483
4484                     //if local directory not found, or particular string does not exist in local direcotry
4485                     $langfile = $location.$parentlang.'/'.$module.'.php';
4486                     if (file_exists($langfile)) {
4487                         if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4488                             eval($result);
4489                             return $resultstring;
4490                         }
4491                     }
4492                 }
4493             }
4494         }
4495     }
4496
4497 /// Our only remaining option is to try English
4498
4499     foreach ($locations as $location) {
4500         $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4501         if (file_exists($locallangfile)) {
4502             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4503                 eval($result);
4504                 return $resultstring;
4505             }
4506         }
4507
4508         //if local_en not found, or string not found in local_en
4509         $langfile = $location.$defaultlang.'/'.$module.'.php';
4510
4511         if (file_exists($langfile)) {
4512             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4513                 eval($result);
4514                 return $resultstring;
4515             }
4516         }
4517     }
4518
4519 /// And, because under 1.6 en is defined as en_utf8 child, me must try
4520 /// if it hasn't been queried before.
4521     if ($defaultlang  == 'en') {
4522         $defaultlang = 'en_utf8';
4523         foreach ($locations as $location) {
4524             $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4525             if (file_exists($locallangfile)) {
4526                 if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4527                     eval($result);
4528                     return $resultstring;
4529                 }
4530             }
4531
4532             //if local_en not found, or string not found in local_en
4533             $langfile = $location.$defaultlang.'/'.$module.'.php';
4534
4535             if (file_exists($langfile)) {
4536                 if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4537                     eval($result);
4538                     return $resultstring;
4539                 }
4540             }
4541         }
4542     }
4543
4544     return '[['.$identifier.']]';  // Last resort
4545 }
4546
4547 /**
4548  * This function is only used from {@link get_string()}.
4549  *
4550  * @internal Only used from get_string, not meant to be public API
4551  * @param string $identifier ?
4552  * @param string $langfile ?
4553  * @param string $destination ?
4554  * @return string|false ?
4555  * @staticvar array $strings Localized strings
4556  * @access private
4557  * @todo Finish documenting this function.
4558  */
4559 function get_string_from_file($identifier, $langfile, $destination) {
4560
4561     static $strings;    // Keep the strings cached in memory.
4562
4563     if (empty($strings[$langfile])) {
4564         $string = array();
4565         include ($langfile);
4566         $strings[$langfile] = $string;
4567     } else {
4568         $string = &$strings[$langfile];
4569     }
4570
4571     if (!isset ($string[$identifier])) {
4572         return false;
4573     }
4574
4575     return $destination .'= sprintf("'. $string[$identifier] .'");';
4576 }
4577
4578 /**
4579  * Converts an array of strings to their localized value.
4580  *
4581  * @param array $array An array of strings
4582  * @param string $module The language module that these strings can be found in.
4583  * @return string
4584  */
4585 function get_strings($array, $module='') {
4586
4587    $string = NULL;
4588    foreach ($array as $item) {
4589        $string->$item = get_string($item, $module);
4590    }
4591    return $string;
4592 }
4593
4594 /**
4595  * Returns a list of language codes and their full names
4596  * hides the _local files from everyone.
4597  * @param bool refreshcache force refreshing of lang cache
4598  * @param bool returnall ignore langlist, return all languages available
4599  * @return array An associative array with contents in the form of LanguageCode => LanguageName
4600  */
4601 function get_list_of_languages($refreshcache=false, $returnall=false) {
4602
4603     global $CFG;
4604
4605     $languages = array();
4606
4607     $filetocheck = 'langconfig.php';
4608
4609     if (!$refreshcache && !$returnall && !empty($CFG->langcache) && file_exists($CFG->dataroot .'/cache/languages')) {
4610 /// read available langs from cache
4611
4612         $lines = file($CFG->dataroot .'/cache/languages');
4613         foreach ($lines as $line) {
4614             $line = trim($line);
4615             if (preg_match('/^(\w+)\s+(.+)/', $line, $matches)) {
4616                 $languages[$matches[1]] = $matches[2];
4617             }
4618         }
4619         unset($lines); unset($line); unset($matches);
4620         return $languages;
4621     }
4622
4623     if (!$returnall && !empty($CFG->langlist)) {
4624 /// return only languages allowed in langlist admin setting
4625
4626         $langlist = explode(',', $CFG->langlist);
4627         // fix short lang names first - non existing langs are skipped anyway...
4628         foreach ($langlist as $lang) {
4629             if (strpos($lang, '_utf8') === false) {
4630                 $langlist[] = $lang.'_utf8';
4631             }
4632         }
4633         // find existing langs from langlist
4634         foreach ($langlist as $lang) {
4635             $lang = trim($lang);   //Just trim spaces to be a bit more permissive
4636             if (strstr($lang, '_local')!==false) {
4637                 continue;
4638             }
4639             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4640                 $shortlang = substr($lang, 0, -5);
4641             } else {
4642                 $shortlang = $lang;
4643             }
4644         /// Search under dirroot/lang
4645             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4646                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4647                 if (!empty($string['thislanguage'])) {
4648                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4649                 }
4650                 unset($string);
4651             }
4652         /// And moodledata/lang
4653             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4654                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4655                 if (!empty($string['thislanguage'])) {
4656                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4657                 }
4658                 unset($string);
4659             }
4660         }
4661
4662     } else {
4663 /// return all languages available in system
4664     /// Fetch langs from moodle/lang directory
4665         $langdirs = get_list_of_plugins('lang');
4666     /// Fetch langs from moodledata/lang directory
4667         $langdirs2 = get_list_of_plugins('lang', '', $CFG->dataroot);
4668     /// Merge both lists of langs
4669         $langdirs = array_merge($langdirs, $langdirs2);
4670     /// Sort all
4671         asort($langdirs);
4672     /// Get some info from each lang (first from moodledata, then from moodle)
4673         foreach ($langdirs as $lang) {
4674             if (strstr($lang, '_local')!==false) {
4675                 continue;
4676             }
4677             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4678                 $shortlang = substr($lang, 0, -5);
4679             } else {
4680                 $shortlang = $lang;
4681             }
4682         /// Search under moodledata/lang
4683             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4684                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4685                 if (!empty($string['thislanguage'])) {
4686                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4687                 }
4688                 unset($string);
4689             }
4690         /// And dirroot/lang
4691             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4692                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4693                 if (!empty($string['thislanguage'])) {
4694                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4695                 }
4696                 unset($string);
4697             }
4698         }
4699     }
4700
4701     if ($refreshcache && !empty($CFG->langcache)) {
4702         if ($returnall) {
4703             // we have a list of all langs only, just delete old cache
4704             @unlink($CFG->dataroot.'/cache/languages');
4705
4706         } else {
4707             // store the list of allowed languages
4708             if ($file = fopen($CFG->dataroot .'/cache/languages', 'w')) {
4709                 foreach ($languages as $key => $value) {
4710                     fwrite($file, "$key $value\n");
4711                 }
4712                 fclose($file);
4713             }
4714         }
4715     }
4716
4717     return $languages;
4718 }
4719
4720 /**
4721  * Returns a list of charset codes. It's hardcoded, so they should be added manually
4722  * (cheking that such charset is supported by the texlib library!)
4723  *
4724  * @return array And associative array with contents in the form of charset => charset
4725  */
4726 function get_list_of_charsets() {
4727
4728     $charsets = array(
4729         'EUC-JP'     => 'EUC-JP',
4730         'ISO-2022-JP'=> 'ISO-2022-JP',
4731         'ISO-8859-1' => 'ISO-8859-1',
4732         'SHIFT-JIS'  => 'SHIFT-JIS',
4733         'GB2312'     => 'GB2312',
4734         'GB18030'    => 'GB18030', // gb18030 not supported by typo and mbstring
4735         'UTF-8'      => 'UTF-8');
4736
4737     asort($charsets);
4738
4739     return $charsets;
4740 }
4741
4742 /**
4743  * Returns a list of country names in the current language
4744  *
4745  * @uses $CFG
4746  * @uses $USER
4747  * @return array
4748  */
4749 function get_list_of_countries() {
4750     global $CFG, $USER;
4751
4752     $lang = current_language();
4753
4754     if (!file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php') &&
4755         !file_exists($CFG->dataroot.'/lang/'. $lang .'/countries.php')) {
4756         if ($parentlang = get_string('parentlanguage')) {
4757             if (file_exists($CFG->dirroot .'/lang/'. $parentlang .'/countries.php') ||
4758                 file_exists($CFG->dataroot.'/lang/'. $parentlang .'/countries.php')) {
4759                 $lang = $parentlang;
4760             } else {
4761                 $lang = 'en_utf8';  // countries.php must exist in this pack
4762             }
4763         } else {
4764             $lang = 'en_utf8';  // countries.php must exist in this pack
4765         }
4766     }
4767
4768     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/countries.php')) {
4769         include($CFG->dataroot .'/lang/'. $lang .'/countries.php');
4770     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php')) {
4771         include($CFG->dirroot .'/lang/'. $lang .'/countries.php');
4772     }
4773
4774     if (!empty($string)) {
4775         asort($string);
4776     }
4777
4778     return $string;
4779 }
4780
4781 /**
4782  * Returns a list of valid and compatible themes
4783  *
4784  * @uses $CFG
4785  * @return array
4786  */
4787 function get_list_of_themes() {
4788
4789     global $CFG;
4790
4791     $themes = array();
4792
4793     if (!empty($CFG->themelist)) {       // use admin's list of themes
4794         $themelist = explode(',', $CFG->themelist);
4795     } else {
4796         $themelist = get_list_of_plugins("theme");
4797     }
4798
4799     foreach ($themelist as $key => $theme) {
4800         if (!file_exists("$CFG->themedir/$theme/config.php")) {   // bad folder
4801             continue;
4802         }
4803         $THEME = new object();    // Note this is not the global one!!  :-)
4804         include("$CFG->themedir/$theme/config.php");
4805         if (!isset($THEME->sheets)) {   // Not a valid 1.5 theme
4806             continue;
4807         }
4808         $themes[$theme] = $theme;
4809     }
4810     asort($themes);
4811
4812     return $themes;
4813 }
4814
4815
4816 /**
4817  * Returns a list of picture names in the current or specified language
4818  *
4819  * @uses $CFG
4820  * @return array
4821  */
4822 function get_list_of_pixnames($lang = '') {
4823     global $CFG;
4824
4825     if (empty($lang)) {
4826         $lang = current_language();
4827     }
4828
4829     $string = array();
4830
4831     $path = $CFG->dirroot .'/lang/en_utf8/pix.php'; // always exists
4832
4833     if (file_exists($CFG->dataroot .'/lang/'. $lang .'_local/pix.php')) {
4834         $path = $CFG->dataroot .'/lang/'. $lang .'_local/pix.php';
4835
4836     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/pix.php')) {
4837         $path = $CFG->dirroot .'/lang/'. $lang .'/pix.php';
4838
4839     } else if (file_exists($CFG->dataroot .'/lang/'. $lang .'/pix.php')) {
4840         $path = $CFG->dataroot .'/lang/'. $lang .'/pix.php';
4841
4842     } else if ($parentlang = get_string('parentlanguage') and $parentlang != '[[parentlanguage]]') {
4843         return get_list_of_pixnames($parentlang); //return pixnames from parent language instead
4844     }
4845
4846     include($path);
4847
4848     return $string;
4849 }
4850
4851 /**
4852  * Returns a list of timezones in the current language
4853  *
4854  * @uses $CFG
4855  * @return array
4856  */
4857 function get_list_of_timezones() {
4858     global $CFG;
4859
4860     $timezones = array();
4861
4862     if ($rawtimezones = get_records_sql('SELECT MAX(id), name FROM '.$CFG->prefix.'timezone GROUP BY name')) {
4863         foreach($rawtimezones as $timezone) {
4864             if (!empty($timezone->name)) {
4865                 $timezones[$timezone->name] = get_string(strtolower($timezone->name), 'timezones');
4866                 if (substr($timezones[$timezone->name], 0, 1) == '[') {  // No translation found
4867                     $timezones[$timezone->name] = $timezone->name;
4868                 }
4869             }
4870         }
4871     }
4872
4873     asort($timezones);
4874
4875     for ($i = -13; $i <= 13; $i += .5) {
4876         $tzstring = 'GMT';
4877         if ($i < 0) {
4878             $timezones[sprintf("%.1f", $i)] = $tzstring . $i;
4879         } else if ($i > 0) {
4880             $timezones[sprintf("%.1f", $i)] = $tzstring . '+' . $i;
4881         } else {
4882             $timezones[sprintf("%.1f", $i)] = $tzstring;
4883         }
4884     }
4885
4886     return $timezones;
4887 }
4888
4889 /**
4890  * Returns a list of currencies in the current language
4891  *
4892  * @uses $CFG
4893  * @uses $USER
4894  * @return array
4895  */
4896 function get_list_of_currencies() {
4897     global $CFG, $USER;
4898
4899     $lang = current_language();
4900
4901     if (!file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
4902         if ($parentlang = get_string('parentlanguage')) {
4903             if (file_exists($CFG->dataroot .'/lang/'. $parentlang .'/currencies.php')) {
4904                 $lang = $parentlang;
4905             } else {
4906                 $lang = 'en_utf8';  // currencies.php must exist in this pack
4907             }
4908         } else {
4909             $lang = 'en_utf8';  // currencies.php must exist in this pack
4910         }
4911     }
4912
4913     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
4914         include_once($CFG->dataroot .'/lang/'. $lang .'/currencies.php');
4915     } else {    //if en_utf8 is not installed in dataroot
4916         include_once($CFG->dirroot .'/lang/'. $lang .'/currencies.php');
4917     }
4918
4919     if (!empty($string)) {
4920         asort($string);
4921     }
4922
4923     return $string;
4924 }
4925
4926
4927
4928 /**
4929  * Can include a given document file (depends on second
4930  * parameter) or just return info about it.
4931  *
4932  * @uses $CFG
4933  * @param string $file ?
4934  * @param bool $include ?
4935  * @return ?
4936  * @todo Finish documenting this function
4937  */
4938 function document_file($file, $include=true) {
4939     global $CFG;
4940
4941     $file = clean_filename($file);
4942
4943     if (empty($file)) {
4944         return false;
4945     }
4946
4947     $langs = array(current_language(), get_string('parentlanguage'), 'en');
4948
4949     foreach ($langs as $lang) {
4950         $info = new object();
4951         $info->filepath = $CFG->dirroot .'/lang/'. $lang .'/docs/'. $file;
4952         $info->urlpath  = $CFG->wwwroot .'/lang/'. $lang .'/docs/'. $file;
4953
4954         if (file_exists($info->filepath)) {
4955             if ($include) {
4956                 include($info->filepath);
4957             }
4958             return $info;
4959         }
4960     }
4961
4962     return false;
4963 }
4964
4965 /// ENCRYPTION  ////////////////////////////////////////////////
4966
4967 /**
4968  * rc4encrypt
4969  *
4970  * @param string $data ?
4971  * @return string
4972  * @todo Finish documenting this function
4973  */
4974 function rc4encrypt($data) {
4975     $password = 'nfgjeingjk';
4976     return endecrypt($password, $data, '');
4977 }
4978
4979 /**
4980  * rc4decrypt
4981  *
4982  * @param string $data ?
4983  * @return string
4984  * @todo Finish documenting this function
4985  */
4986 function rc4decrypt($data) {
4987     $password = 'nfgjeingjk';
4988     return endecrypt($password, $data, 'de');
4989 }
4990
4991 /**
4992  * Based on a class by Mukul Sabharwal [mukulsabharwal @ yahoo.com]
4993  *
4994  * @param string $pwd ?
4995  * @param string $data ?
4996  * @param string $case ?
4997  * @return string
4998  * @todo Finish documenting this function
4999  */
5000 function endecrypt ($pwd, $data, $case) {
5001
5002     if ($case == 'de') {
5003         $data = urldecode($data);
5004     }
5005
5006     $key[] = '';
5007     $box[] = '';
5008     $temp_swap = '';
5009     $pwd_length = 0;
5010
5011     $pwd_length = strlen($pwd);
5012
5013     for ($i = 0; $i <= 255; $i++) {
5014         $key[$i] = ord(substr($pwd, ($i % $pwd_length), 1));
5015         $box[$i] = $i;
5016     }
5017
5018     $x = 0;
5019
5020     for ($i = 0; $i <= 255; $i++) {
5021         $x = ($x + $box[$i] + $key[$i]) % 256;
5022         $temp_swap = $box[$i];
5023         $box[$i] = $box[$x];
5024         $box[$x] = $temp_swap;
5025     }
5026
5027     $temp = '';
5028     $k = '';
5029
5030     $cipherby = '';
5031     $cipher = '';
5032
5033     $a = 0;
5034     $j = 0;
5035
5036     for ($i = 0; $i < strlen($data); $i++) {
5037         $a = ($a + 1) % 256;
5038         $j = ($j + $box[$a]) % 256;
5039         $temp = $box[$a];
5040         $box[$a] = $box[$j];
5041         $box[$j] = $temp;
5042         $k = $box[(($box[$a] + $box[$j]) % 256)];
5043         $cipherby = ord(substr($data, $i, 1)) ^ $k;
5044         $cipher .= chr($cipherby);
5045     }
5046
5047     if ($case == 'de') {
5048         $cipher = urldecode(urlencode($cipher));
5049     } else {
5050         $cipher = urlencode($cipher);
5051     }
5052
5053     return $cipher;
5054 }
5055
5056
5057 /// CALENDAR MANAGEMENT  ////////////////////////////////////////////////////////////////
5058
5059
5060 /**
5061  * Call this function to add an event to the calendar table
5062  *  and to call any calendar plugins
5063  *
5064  * @uses $CFG
5065  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field. The object event should include the following:
5066  *  <ul>
5067  *    <li><b>$event->name</b> - Name for the event
5068  *    <li><b>$event->description</b> - Description of the event (defaults to '')
5069  *    <li><b>$event->format</b> - Format for the description (using formatting types defined at the top of weblib.php)
5070  *    <li><b>$event->courseid</b> - The id of the course this event belongs to (0 = all courses)
5071  *    <li><b>$event->groupid</b> - The id of the group this event belongs to (0 = no group)
5072  *    <li><b>$event->userid</b> - The id of the user this event belongs to (0 = no user)
5073  *    <li><b>$event->modulename</b> - Name of the module that creates this event
5074  *    <li><b>$event->instance</b> - Instance of the module that owns this event
5075  *    <li><b>$event->eventtype</b> - The type info together with the module info could
5076  *             be used by calendar plugins to decide how to display event
5077  *    <li><b>$event->timestart</b>- Timestamp for start of event
5078  *    <li><b>$event->timeduration</b> - Duration (defaults to zero)
5079  *    <li><b>$event->visible</b> - 0 if the event should be hidden (e.g. because the activity that created it is hidden)
5080  *  </ul>
5081  * @return int The id number of the resulting record
5082  */
5083  function add_event($event) {
5084
5085     global $CFG;
5086
5087     $event->timemodified = time();
5088
5089     if (!$event->id = insert_record('event', $event)) {
5090         return false;
5091     }
5092
5093     if (!empty($CFG->calendar)) { // call the add_event function of the selected calendar
5094         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5095             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5096             $calendar_add_event = $CFG->calendar.'_add_event';
5097             if (function_exists($calendar_add_event)) {
5098                 $calendar_add_event($event);
5099             }
5100         }
5101     }
5102
5103     return $event->id;
5104 }
5105
5106 /**
5107  * Call this function to update an event in the calendar table
5108  * the event will be identified by the id field of the $event object.
5109  *
5110  * @uses $CFG
5111  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5112  * @return bool
5113  */
5114 function update_event($event) {
5115
5116     global $CFG;
5117
5118     $event->timemodified = time();
5119
5120     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5121         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5122             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5123             $calendar_update_event = $CFG->calendar.'_update_event';
5124             if (function_exists($calendar_update_event)) {
5125                 $calendar_update_event($event);
5126             }
5127         }
5128     }
5129     return update_record('event', $event);
5130 }
5131
5132 /**
5133  * Call this function to delete the event with id $id from calendar table.
5134  *
5135  * @uses $CFG
5136  * @param int $id The id of an event from the 'calendar' table.
5137  * @return array An associative array with the results from the SQL call.
5138  * @todo Verify return type
5139  */
5140 function delete_event($id) {
5141
5142     global $CFG;
5143
5144     if (!empty($CFG->calendar)) { // call the delete_event function of the selected calendar
5145         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5146             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5147             $calendar_delete_event = $CFG->calendar.'_delete_event';
5148             if (function_exists($calendar_delete_event)) {
5149                 $calendar_delete_event($id);
5150             }
5151         }
5152     }
5153     return delete_records('event', 'id', $id);
5154 }
5155
5156 /**
5157  * Call this function to hide an event in the calendar table
5158  * the event will be identified by the id field of the $event object.
5159  *
5160  * @uses $CFG
5161  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5162  * @return array An associative array with the results from the SQL call.
5163  * @todo Verify return type
5164  */
5165 function hide_event($event) {
5166     global $CFG;
5167
5168     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5169         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5170             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5171             $calendar_hide_event = $CFG->calendar.'_hide_event';
5172             if (function_exists($calendar_hide_event)) {
5173                 $calendar_hide_event($event);
5174             }
5175         }
5176     }
5177     return set_field('event', 'visible', 0, 'id', $event->id);
5178 }
5179
5180 /**
5181  * Call this function to unhide an event in the calendar table
5182  * the event will be identified by the id field of the $event object.
5183  *
5184  * @uses $CFG
5185  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5186  * @return array An associative array with the results from the SQL call.
5187  * @todo Verify return type
5188  */
5189 function show_event($event) {
5190     global $CFG;
5191
5192     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5193         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5194             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5195             $calendar_show_event = $CFG->calendar.'_show_event';
5196             if (function_exists($calendar_show_event)) {
5197                 $calendar_show_event($event);
5198             }
5199         }
5200     }
5201     return set_field('event', 'visible', 1, 'id', $event->id);
5202 }
5203
5204
5205 /// ENVIRONMENT CHECKING  ////////////////////////////////////////////////////////////
5206
5207 /**
5208  * Lists plugin directories within some directory
5209  *
5210  * @uses $CFG
5211  * @param string $plugin dir under we'll look for plugins (defaults to 'mod')
5212  * @param string $exclude dir name to exclude from the list (defaults to none)
5213  * @param string $basedir full path to the base dir where $plugin resides (defaults to $CFG->dirroot)
5214  * @return array of plugins found under the requested parameters
5215  */
5216 function get_list_of_plugins($plugin='mod', $exclude='', $basedir='') {
5217
5218     global $CFG;
5219
5220     $plugins = array();
5221
5222     if (empty($basedir)) {
5223
5224         # This switch allows us to use the appropiate theme directory - and potentialy alternatives for other plugins
5225         switch ($plugin) {
5226         case "theme":
5227             $basedir = $CFG->themedir;
5228             break;
5229
5230         default:
5231             $basedir = $CFG->dirroot .'/'. $plugin;
5232         }
5233
5234     } else {
5235         $basedir = $basedir .'/'. $plugin;
5236     }
5237
5238     if (file_exists($basedir) && filetype($basedir) == 'dir') {
5239         $dirhandle = opendir($basedir);
5240         while (false !== ($dir = readdir($dirhandle))) {
5241             $firstchar = substr($dir, 0, 1);
5242             if ($firstchar == '.' or $dir == 'CVS' or $dir == '_vti_cnf' or $dir == $exclude) {
5243                 continue;
5244             }
5245             if (filetype($basedir .'/'. $dir) != 'dir') {
5246                 continue;
5247             }
5248             $plugins[] = $dir;
5249         }
5250         closedir($dirhandle);
5251     }
5252     if ($plugins) {
5253         asort($plugins);
5254     }
5255     return $plugins;
5256 }
5257
5258 /**
5259  * Returns true if the current version of PHP is greater that the specified one.
5260  *
5261  * @param string $version The version of php being tested.
5262  * @return bool
5263  */
5264 function check_php_version($version='4.1.0') {
5265     return (version_compare(phpversion(), $version) >= 0);
5266 }
5267
5268
5269 /**
5270  * Checks to see if is a browser matches the specified
5271  * brand and is equal or better version.
5272  *
5273  * @uses $_SERVER
5274  * @param string $brand The browser identifier being tested
5275  * @param int $version The version of the browser
5276  * @return bool true if the given version is below that of the detected browser
5277  */
5278  function check_browser_version($brand='MSIE', $version=5.5) {
5279     if (empty($_SERVER['HTTP_USER_AGENT'])) {
5280         return false;
5281     }
5282
5283     $agent = $_SERVER['HTTP_USER_AGENT'];
5284
5285     switch ($brand) {
5286
5287       case 'Camino':   /// Mozilla Firefox browsers
5288
5289               if (preg_match("/Camino\/([0-9\.]+)/i", $agent, $match)) {
5290                   if (version_compare($match[1], $version) >= 0) {
5291                       return true;
5292                   }
5293               }
5294               break;
5295
5296
5297       case 'Firefox':   /// Mozilla Firefox browsers
5298
5299           if (preg_match("/Firefox\/([0-9\.]+)/i", $agent, $match)) {
5300               if (version_compare($match[1], $version) >= 0) {
5301                   return true;
5302               }
5303           }
5304           break;
5305
5306
5307       case 'Gecko':   /// Gecko based browsers
5308
5309           if (substr_count($agent, 'Camino')) {
5310               // MacOS X Camino support
5311               $version = 20041110;
5312           }
5313
5314           // the proper string - Gecko/CCYYMMDD Vendor/Version
5315           // Faster version and work-a-round No IDN problem.
5316           if (preg_match("/Gecko\/([0-9]+)/i", $agent, $match)) {
5317               if ($match[1] > $version) {
5318                       return true;
5319                   }
5320               }
5321           break;
5322
5323
5324       case 'MSIE':   /// Internet Explorer
5325
5326           if (strpos($agent, 'Opera')) {     // Reject Opera
5327               return false;
5328           }
5329           $string = explode(';', $agent);
5330           if (!isset($string[1])) {
5331               return false;
5332           }
5333           $string = explode(' ', trim($string[1]));
5334           if (!isset($string[0]) and !isset($string[1])) {
5335               return false;
5336           }
5337           if ($string[0] == $brand and (float)$string[1] >= $version ) {
5338               return true;
5339           }
5340           break;
5341
5342       case 'Opera':  /// Opera
5343
5344           if (preg_match("/Opera\/([0-9\.]+)/i", $agent, $match)) {
5345               if (version_compare($match[1], $version) >= 0) {
5346                   return true;
5347               }
5348           }
5349           break;
5350
5351       case 'Safari':  /// Safari
5352           // Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SimbianOS
5353           if (strpos($agent, 'OmniWeb')) { // Reject OmniWeb
5354               return false;
5355           } elseif (strpos($agent, 'Shiira')) { // Reject Shiira
5356               return false;
5357           } elseif (strpos($agent, 'SimbianOS')) { // Reject SimbianOS
5358               return false;
5359           }
5360
5361           if (preg_match("/AppleWebKit\/([0-9]+)/i", $agent, $match)) {
5362               if (version_compare($match[1], $version) >= 0) {
5363                   return true;
5364               }
5365           }
5366
5367           break;
5368
5369     }
5370
5371     return false;
5372 }
5373
5374 /**
5375  * This function makes the return value of ini_get consistent if you are
5376  * setting server directives through the .htaccess file in apache.
5377  * Current behavior for value set from php.ini On = 1, Off = [blank]
5378  * Current behavior for value set from .htaccess On = On, Off = Off
5379  * Contributed by jdell @ unr.edu
5380  *
5381  * @param string $ini_get_arg ?
5382  * @return bool
5383  * @todo Finish documenting this function
5384  */
5385 function ini_get_bool($ini_get_arg) {
5386     $temp = ini_get($ini_get_arg);
5387
5388     if ($temp == '1' or strtolower($temp) == 'on') {
5389         return true;
5390     }
5391     return false;
5392 }
5393
5394 /**
5395  * Compatibility stub to provide backward compatibility
5396  *
5397  * Determines if the HTML editor is enabled.
5398  * @deprecated Use {@link can_use_html_editor()} instead.
5399  */
5400  function can_use_richtext_editor() {
5401     return can_use_html_editor();
5402 }
5403
5404 /**
5405  * Determines if the HTML editor is enabled.
5406  *
5407  * This depends on site and user
5408  * settings, as well as the current browser being used.
5409  *
5410  * @return string|false Returns false if editor is not being used, otherwise
5411  * returns 'MSIE' or 'Gecko'.
5412  */
5413  function can_use_html_editor() {
5414     global $USER, $CFG;
5415
5416     if (!empty($USER->htmleditor) and !empty($CFG->htmleditor)) {
5417         if (check_browser_version('MSIE', 5.5)) {
5418             return 'MSIE';
5419         } else if (check_browser_version('Gecko', 20030516)) {
5420             return 'Gecko';
5421         }
5422     }
5423     return false;
5424 }
5425
5426 /**
5427  * Hack to find out the GD version by parsing phpinfo output
5428  *
5429  * @return int GD version (1, 2, or 0)
5430  */
5431 function check_gd_version() {
5432     $gdversion = 0;
5433
5434     if (function_exists('gd_info')){
5435         $gd_info = gd_info();
5436         if (substr_count($gd_info['GD Version'], '2.')) {
5437             $gdversion = 2;
5438         } else if (substr_count($gd_info['GD Version'], '1.')) {
5439             $gdversion = 1;
5440         }
5441
5442     } else {
5443         ob_start();
5444         phpinfo(8);
5445         $phpinfo = ob_get_contents();
5446         ob_end_clean();
5447
5448         $phpinfo = explode("\n", $phpinfo);
5449
5450
5451         foreach ($phpinfo as $text) {
5452             $parts = explode('</td>', $text);
5453             foreach ($parts as $key => $val) {
5454                 $parts[$key] = trim(strip_tags($val));
5455             }
5456             if ($parts[0] == 'GD Version') {
5457                 if (substr_count($parts[1], '2.0')) {
5458                     $parts[1] = '2.0';
5459                 }
5460                 $gdversion = intval($parts[1]);
5461             }
5462         }
5463     }
5464
5465     return $gdversion;   // 1, 2 or 0
5466 }
5467
5468 /**
5469  * Determine if moodle installation requires update
5470  *
5471  * Checks version numbers of main code and all modules to see
5472  * if there are any mismatches
5473  *
5474  * @uses $CFG
5475  * @return bool
5476  */
5477 function moodle_needs_upgrading() {
5478     global $CFG;
5479
5480     $version = null;
5481     include_once($CFG->dirroot .'/version.php');  # defines $version and upgrades
5482     if ($CFG->version) {
5483         if ($version > $CFG->version) {
5484             return true;
5485         }
5486         if ($mods = get_list_of_plugins('mod')) {
5487             foreach ($mods as $mod) {
5488                 $fullmod = $CFG->dirroot .'/mod/'. $mod;
5489                 $module = new object();
5490                 if (!is_readable($fullmod .'/version.php')) {
5491                     notify('Module "'. $mod .'" is not readable - check permissions');
5492                     continue;
5493                 }
5494                 include_once($fullmod .'/version.php');  # defines $module with version etc
5495                 if ($currmodule = get_record('modules', 'name', $mod)) {
5496                     if ($module->version > $currmodule->version) {
5497                         return true;
5498                     }
5499                 }
5500             }
5501         }
5502     } else {
5503         return true;
5504     }
5505     return false;
5506 }
5507
5508
5509 /// MISCELLANEOUS ////////////////////////////////////////////////////////////////////
5510
5511 /**
5512  * Notify admin users or admin user of any failed logins (since last notification).
5513  *
5514  * @uses $CFG
5515  * @uses $db
5516  * @uses HOURSECS
5517  */
5518 function notify_login_failures() {
5519     global $CFG, $db;
5520
5521     switch ($CFG->notifyloginfailures) {
5522         case 'mainadmin' :
5523             $recip = array(get_admin());
5524             break;
5525         case 'alladmins':
5526             $recip = get_admins();
5527             break;
5528     }
5529
5530     if (empty($CFG->lastnotifyfailure)) {
5531         $CFG->lastnotifyfailure=0;
5532     }
5533
5534     // we need to deal with the threshold stuff first.
5535     if (empty($CFG->notifyloginthreshold)) {
5536         $CFG->notifyloginthreshold = 10; // default to something sensible.
5537     }
5538
5539     $notifyipsrs = $db->Execute('SELECT ip FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5540                           AND module=\'login\' AND action=\'error\' GROUP BY ip HAVING count(*) > '. $CFG->notifyloginthreshold);
5541
5542     $notifyusersrs = $db->Execute('SELECT info FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5543                           AND module=\'login\' AND action=\'error\' GROUP BY info HAVING count(*) > '. $CFG->notifyloginthreshold);
5544
5545     if ($notifyipsrs) {
5546         $ipstr = '';
5547         while ($row = rs_fetch_next_record($notifyipsrs)) {
5548             $ipstr .= "'". $row->ip ."',";
5549         }
5550         rs_close($notifyipsrs);
5551         $ipstr = substr($ipstr,0,strlen($ipstr)-1);
5552     }
5553     if ($notifyusersrs) {
5554         $userstr = '';
5555         while ($row = rs_fetch_next_record($notifyusersrs)) {
5556             $userstr .= "'". $row->info ."',";
5557         }
5558         rs_close($notifyusersrs);
5559         $userstr = substr($userstr,0,strlen($userstr)-1);
5560     }
5561
5562     if (strlen($userstr) > 0 || strlen($ipstr) > 0) {
5563         $count = 0;
5564         $logs = get_logs('time > '. $CFG->lastnotifyfailure .' AND module=\'login\' AND action=\'error\' '
5565                  .((strlen($ipstr) > 0 && strlen($userstr) > 0) ? ' AND ( ip IN ('. $ipstr .') OR info IN ('. $userstr .') ) '
5566                  : ((strlen($ipstr) != 0) ? ' AND ip IN ('. $ipstr .') ' : ' AND info IN ('. $userstr .') ')), 'l.time DESC', '', '', $count);
5567
5568         // if we haven't run in the last hour and we have something useful to report and we are actually supposed to be reporting to somebody
5569         if (is_array($recip) and count($recip) > 0 and ((time() - HOURSECS) > $CFG->lastnotifyfailure)
5570             and is_array($logs) and count($logs) > 0) {
5571
5572             $message = '';
5573             $site = get_site();
5574             $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));
5575             $message .= get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot)
5576                  .(($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n";
5577             foreach ($logs as $log) {
5578                 $log->time = userdate($log->time);
5579                 $message .= get_string('notifyloginfailuresmessage','',$log)."\n";
5580             }
5581             $message .= "\n\n".get_string('notifyloginfailuresmessageend','',$CFG->wwwroot)."\n\n";
5582             foreach ($recip as $admin) {
5583                 mtrace('Emailing '. $admin->username .' about '. count($logs) .' failed login attempts');
5584                 email_to_user($admin,get_admin(),$subject,$message);
5585             }
5586             $conf = new object();
5587             $conf->name = 'lastnotifyfailure';
5588             $conf->value = time();
5589             if ($current = get_record('config', 'name', 'lastnotifyfailure')) {
5590                 $conf->id = $current->id;
5591                 if (! update_record('config', $conf)) {
5592                     mtrace('Could not update last notify time');
5593                 }
5594
5595             } else if (! insert_record('config', $conf)) {
5596                 mtrace('Could not set last notify time');
5597             }
5598         }
5599     }
5600 }
5601
5602 /**
5603  * moodle_setlocale
5604  *
5605  * @uses $CFG
5606  * @param string $locale ?
5607  * @todo Finish documenting this function
5608  */
5609 function moodle_setlocale($locale='') {
5610
5611     global $CFG;
5612
5613     static $currentlocale = ''; // last locale caching
5614
5615     $oldlocale = $currentlocale;
5616
5617 /// Fetch the correct locale based on ostype
5618     if($CFG->ostype == 'WINDOWS') {
5619         $stringtofetch = 'localewin';
5620     } else {
5621         $stringtofetch = 'locale';
5622     }
5623
5624 /// the priority is the same as in get_string() - parameter, config, course, session, user, global language
5625     if (!empty($locale)) {
5626         $currentlocale = $locale;
5627     } else if (!empty($CFG->locale)) { // override locale for all language packs
5628         $currentlocale = $CFG->locale;
5629     } else {
5630         $currentlocale = get_string($stringtofetch);
5631     }
5632
5633 /// do nothing if locale already set up
5634     if ($oldlocale == $currentlocale) {
5635         return;
5636     }
5637
5638 /// Due to some strange BUG we cannot set the LC_TIME directly, so we fetch current values,
5639 /// set LC_ALL and then set values again. Just wondering why we cannot set LC_ALL only??? - stronk7
5640 /// Some day, numeric, monetary and other categories should be set too, I think. :-/
5641
5642 /// Get current values
5643     $monetary= setlocale (LC_MONETARY, 0);
5644     $numeric = setlocale (LC_NUMERIC, 0);
5645     $ctype   = setlocale (LC_CTYPE, 0);
5646     if ($CFG->ostype != 'WINDOWS') {
5647         $messages= setlocale (LC_MESSAGES, 0);
5648     }
5649 /// Set locale to all
5650     setlocale (LC_ALL, $currentlocale);
5651 /// Set old values
5652     setlocale (LC_MONETARY, $monetary);
5653     setlocale (LC_NUMERIC, $numeric);
5654     if ($CFG->ostype != 'WINDOWS') {
5655         setlocale (LC_MESSAGES, $messages);
5656     }
5657     if ($currentlocale == 'tr_TR' or $currentlocale == 'tr_TR.UTF-8') { // To workaround a well-known PHP problem with Turkish letter Ii
5658         setlocale (LC_CTYPE, $ctype);
5659     }
5660 }
5661
5662 /**
5663  * Converts string to lowercase using most compatible function available.
5664  *
5665  * @param string $string The string to convert to all lowercase characters.
5666  * @param string $encoding The encoding on the string.
5667  * @return string
5668  * @todo Add examples of calling this function with/without encoding types
5669  * @deprecated Use textlib->strtolower($text) instead.
5670  */
5671 function moodle_strtolower ($string, $encoding='') {
5672
5673     //If not specified use utf8
5674     if (empty($encoding)) {
5675         $encoding = 'UTF-8';
5676     }
5677     //Use text services
5678     $textlib = textlib_get_instance();
5679
5680     return $textlib->strtolower($string, $encoding);
5681 }
5682
5683 /**
5684  * Count words in a string.
5685  *
5686  * Words are defined as things between whitespace.
5687  *
5688  * @param string $string The text to be searched for words.
5689  * @return int The count of words in the specified string
5690  */
5691 function count_words($string) {
5692     $string = strip_tags($string);
5693     return count(preg_split("/\w\b/", $string)) - 1;
5694 }
5695
5696 /** Count letters in a string.
5697  *
5698  * Letters are defined as chars not in tags and different from whitespace.
5699  *
5700  * @param string $string The text to be searched for letters.
5701  * @return int The count of letters in the specified text.
5702  */
5703 function count_letters($string) {
5704 /// Loading the textlib singleton instance. We are going to need it.
5705     $textlib = textlib_get_instance();
5706
5707     $string = strip_tags($string); // Tags are out now
5708     $string = ereg_replace('[[:space:]]*','',$string); //Whitespace are out now
5709
5710     return $textlib->strlen($string);
5711 }
5712
5713 /**
5714  * Generate and return a random string of the specified length.
5715  *
5716  * @param int $length The length of the string to be created.
5717  * @return string
5718  */
5719 function random_string ($length=15) {
5720     $pool  = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
5721     $pool .= 'abcdefghijklmnopqrstuvwxyz';
5722     $pool .= '0123456789';
5723     $poollen = strlen($pool);
5724     mt_srand ((double) microtime() * 1000000);
5725     $string = '';
5726     for ($i = 0; $i < $length; $i++) {
5727         $string .= substr($pool, (mt_rand()%($poollen)), 1);
5728     }
5729     return $string;
5730 }
5731
5732 /*
5733  * Given some text (which may contain HTML) and an ideal length,
5734  * this function truncates the text neatly on a word boundary if possible
5735  */
5736 function shorten_text($text, $ideal=30) {
5737
5738    global $CFG;
5739
5740
5741    $i = 0;
5742    $tag = false;
5743    $length = strlen($text);
5744    $count = 0;
5745    $stopzone = false;
5746    $truncate = 0;
5747
5748    if ($length <= $ideal) {
5749        return $text;
5750    }
5751
5752    for ($i=0; $i<$length; $i++) {
5753        $char = $text[$i];
5754
5755        switch ($char) {
5756            case "<":
5757                $tag = true;
5758                break;
5759            case ">":
5760                $tag = false;
5761                break;
5762            default:
5763                if (!$tag) {
5764                    if ($stopzone) {
5765                        if ($char == '.' or $char == ' ') {
5766                            $truncate = $i+1;
5767                            break 2;
5768                        } else if (ord($char) >= 0xE0) {  // Chinese/Japanese/Korean text
5769                            $truncate = $i;               // can be truncated at any UTF-8
5770                            break 2;                      // character boundary.
5771                        }
5772                    }
5773                    $count++;
5774                }
5775                break;
5776        }
5777        if (!$stopzone) {
5778            if ($count > $ideal) {
5779                $stopzone = true;
5780            }
5781        }
5782    }
5783
5784    if (!$truncate) {
5785        $truncate = $i;
5786    }
5787
5788    $ellipse = ($truncate < $length) ? '...' : '';
5789
5790    return substr($text, 0, $truncate).$ellipse;
5791 }
5792
5793
5794 /**
5795  * Given dates in seconds, how many weeks is the date from startdate
5796  * The first week is 1, the second 2 etc ...
5797  *
5798  * @uses WEEKSECS
5799  * @param ? $startdate ?
5800  * @param ? $thedate ?
5801  * @return string
5802  * @todo Finish documenting this function
5803  */
5804 function getweek ($startdate, $thedate) {
5805     if ($thedate < $startdate) {   // error
5806         return 0;
5807     }
5808
5809     return floor(($thedate - $startdate) / WEEKSECS) + 1;
5810 }
5811
5812 /**
5813  * returns a randomly generated password of length $maxlen.  inspired by
5814  * {@link http://www.phpbuilder.com/columns/jesus19990502.php3}
5815  *
5816  * @param int $maxlength  The maximum size of the password being generated.
5817  * @return string
5818  */
5819 function generate_password($maxlen=10) {
5820     global $CFG;
5821
5822     $fillers = '1234567890!$-+';
5823     $wordlist = file($CFG->wordlist);
5824
5825     srand((double) microtime() * 1000000);
5826     $word1 = trim($wordlist[rand(0, count($wordlist) - 1)]);
5827     $word2 = trim($wordlist[rand(0, count($wordlist) - 1)]);
5828     $filler1 = $fillers[rand(0, strlen($fillers) - 1)];
5829
5830     return substr($word1 . $filler1 . $word2, 0, $maxlen);
5831 }
5832
5833 /**
5834  * Given a float, prints it nicely
5835  *
5836  * @param float $num The float to print
5837  * @param int $places The number of decimal places to print.
5838  * @return string
5839  */
5840 function format_float($num, $places=1) {
5841     return sprintf("%.$places"."f", $num);
5842 }
5843
5844 /**
5845  * Given a simple array, this shuffles it up just like shuffle()
5846  * Unlike PHP's shuffle() ihis function works on any machine.
5847  *
5848  * @param array $array The array to be rearranged
5849  * @return array
5850  */
5851 function swapshuffle($array) {
5852
5853     srand ((double) microtime() * 10000000);
5854     $last = count($array) - 1;
5855     for ($i=0;$i<=$last;$i++) {
5856         $from = rand(0,$last);
5857         $curr = $array[$i];
5858         $array[$i] = $array[$from];
5859         $array[$from] = $curr;
5860     }
5861     return $array;
5862 }
5863
5864 /**
5865  * Like {@link swapshuffle()}, but works on associative arrays
5866  *
5867  * @param array $array The associative array to be rearranged
5868  * @return array
5869  */
5870 function swapshuffle_assoc($array) {
5871 ///
5872
5873     $newkeys = swapshuffle(array_keys($array));
5874     foreach ($newkeys as $newkey) {
5875         $newarray[$newkey] = $array[$newkey];
5876     }
5877     return $newarray;
5878 }
5879
5880 /**
5881  * Given an arbitrary array, and a number of draws,
5882  * this function returns an array with that amount
5883  * of items.  The indexes are retained.
5884  *
5885  * @param array $array ?
5886  * @param ? $draws ?
5887  * @return ?
5888  * @todo Finish documenting this function
5889  */
5890 function draw_rand_array($array, $draws) {
5891     srand ((double) microtime() * 10000000);
5892
5893     $return = array();
5894
5895     $last = count($array);
5896
5897     if ($draws > $last) {
5898         $draws = $last;
5899     }
5900
5901     while ($draws > 0) {
5902         $last--;
5903
5904         $keys = array_keys($array);
5905         $rand = rand(0, $last);
5906
5907         $return[$keys[$rand]] = $array[$keys[$rand]];
5908         unset($array[$keys[$rand]]);
5909
5910         $draws--;
5911     }
5912
5913     return $return;
5914 }
5915
5916 /**
5917  * microtime_diff
5918  *
5919  * @param string $a ?
5920  * @param string $b ?
5921  * @return string
5922  * @todo Finish documenting this function
5923  */
5924 function microtime_diff($a, $b) {
5925     list($a_dec, $a_sec) = explode(' ', $a);
5926     list($b_dec, $b_sec) = explode(' ', $b);
5927     return $b_sec - $a_sec + $b_dec - $a_dec;
5928 }
5929
5930 /**
5931  * Given a list (eg a,b,c,d,e) this function returns
5932  * an array of 1->a, 2->b, 3->c etc
5933  *
5934  * @param array $list ?
5935  * @param string $separator ?
5936  * @todo Finish documenting this function
5937  */
5938 function make_menu_from_list($list, $separator=',') {
5939
5940     $array = array_reverse(explode($separator, $list), true);
5941     foreach ($array as $key => $item) {
5942         $outarray[$key+1] = trim($item);
5943     }
5944     return $outarray;
5945 }
5946
5947 /**
5948  * Creates an array that represents all the current grades that
5949  * can be chosen using the given grading type.  Negative numbers
5950  * are scales, zero is no grade, and positive numbers are maximum
5951  * grades.
5952  *
5953  * @param int $gradingtype ?
5954  * return int
5955  * @todo Finish documenting this function
5956  */
5957 function make_grades_menu($gradingtype) {
5958     $grades = array();
5959     if ($gradingtype < 0) {
5960         if ($scale = get_record('scale', 'id', - $gradingtype)) {
5961             return make_menu_from_list($scale->scale);
5962         }
5963     } else if ($gradingtype > 0) {
5964         for ($i=$gradingtype; $i>=0; $i--) {
5965             $grades[$i] = $i .' / '. $gradingtype;
5966         }
5967         return $grades;
5968     }
5969     return $grades;
5970 }
5971
5972 /**
5973  * This function returns the nummber of activities
5974  * using scaleid in a courseid
5975  *
5976  * @param int $courseid ?
5977  * @param int $scaleid ?
5978  * @return int
5979  * @todo Finish documenting this function
5980  */
5981 function course_scale_used($courseid, $scaleid) {
5982
5983     global $CFG;
5984
5985     $return = 0;
5986
5987     if (!empty($scaleid)) {
5988         if ($cms = get_course_mods($courseid)) {
5989             foreach ($cms as $cm) {
5990                 //Check cm->name/lib.php exists
5991                 if (file_exists($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php')) {
5992                     include_once($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php');
5993                     $function_name = $cm->modname.'_scale_used';
5994                     if (function_exists($function_name)) {
5995                         if ($function_name($cm->instance,$scaleid)) {
5996                             $return++;
5997                         }
5998                     }
5999                 }
6000             }
6001         }
6002     }
6003     return $return;
6004 }
6005
6006 /**
6007  * This function returns the nummber of activities
6008  * using scaleid in the entire site
6009  *
6010  * @param int $scaleid ?
6011  * @return int
6012  * @todo Finish documenting this function. Is return type correct?
6013  */
6014 function site_scale_used($scaleid,&$courses) {
6015
6016     global $CFG;
6017
6018     $return = 0;
6019
6020     if (!is_array($courses) || count($courses) == 0) {
6021         $courses = get_courses("all",false,"c.id,c.shortname");
6022     }
6023
6024     if (!empty($scaleid)) {
6025         if (is_array($courses) && count($courses) > 0) {
6026             foreach ($courses as $course) {
6027                 $return += course_scale_used($course->id,$scaleid);
6028             }
6029         }
6030     }
6031     return $return;
6032 }
6033
6034 /**
6035  * make_unique_id_code
6036  *
6037  * @param string $extra ?
6038  * @return string
6039  * @todo Finish documenting this function
6040  */
6041 function make_unique_id_code($extra='') {
6042
6043     $hostname = 'unknownhost';
6044     if (!empty($_SERVER['HTTP_HOST'])) {
6045         $hostname = $_SERVER['HTTP_HOST'];
6046     } else if (!empty($_ENV['HTTP_HOST'])) {
6047         $hostname = $_ENV['HTTP_HOST'];
6048     } else if (!empty($_SERVER['SERVER_NAME'])) {
6049         $hostname = $_SERVER['SERVER_NAME'];
6050     } else if (!empty($_ENV['SERVER_NAME'])) {
6051         $hostname = $_ENV['SERVER_NAME'];
6052     }
6053
6054     $date = gmdate("ymdHis");
6055
6056     $random =  random_string(6);
6057
6058     if ($extra) {
6059         return $hostname .'+'. $date .'+'. $random .'+'. $extra;
6060     } else {
6061         return $hostname .'+'. $date .'+'. $random;
6062     }
6063 }
6064
6065
6066 /**
6067  * Function to check the passed address is within the passed subnet
6068  *
6069  * The parameter is a comma separated string of subnet definitions.
6070  * Subnet strings can be in one of three formats:
6071  *   1: xxx.xxx.xxx.xxx/xx
6072  *   2: xxx.xxx
6073  *   3: xxx.xxx.xxx.xxx-xxx   //a range of IP addresses in the last group.
6074  * Code for type 1 modified from user posted comments by mediator at
6075  * {@link http://au.php.net/manual/en/function.ip2long.php}
6076  *
6077  * @param string $addr    The address you are checking
6078  * @param string $subnetstr    The string of subnet addresses
6079  * @return bool
6080  */
6081 function address_in_subnet($addr, $subnetstr) {
6082
6083     $subnets = explode(',', $subnetstr);
6084     $found = false;
6085     $addr = trim($addr);
6086
6087     foreach ($subnets as $subnet) {
6088         $subnet = trim($subnet);
6089         if (strpos($subnet, '/') !== false) { /// type 1
6090             list($ip, $mask) = explode('/', $subnet);
6091             $mask = 0xffffffff << (32 - $mask);
6092             $found = ((ip2long($addr) & $mask) == (ip2long($ip) & $mask));
6093         } else if (strpos($subnet, '-') !== false)  {/// type 3
6094             $subnetparts = explode('.', $subnet);
6095             $addrparts = explode('.', $addr);
6096             $subnetrange = explode('-', array_pop($subnetparts));
6097             if (count($subnetrange) == 2) {
6098                 $lastaddrpart = array_pop($addrparts);
6099                 $found = ($subnetparts == $addrparts &&
6100                         $subnetrange[0] <= $lastaddrpart && $lastaddrpart <= $subnetrange[1]);
6101             }
6102         } else { /// type 2
6103             $found = (strpos($addr, $subnet) === 0);
6104         }
6105
6106         if ($found) {
6107             break;
6108         }
6109     }
6110     return $found;
6111 }
6112
6113 /**
6114  * This function sets the $HTTPSPAGEREQUIRED global
6115  * (used in some parts of moodle to change some links)
6116  * and calculate the proper wwwroot to be used
6117  *
6118  * By using this function properly, we can ensure 100% https-ized pages
6119  * at our entire discretion (login, forgot_password, change_password)
6120  */
6121 function httpsrequired() {
6122
6123     global $CFG, $HTTPSPAGEREQUIRED;
6124
6125     if (!empty($CFG->loginhttps)) {
6126         $HTTPSPAGEREQUIRED = true;
6127         $CFG->httpswwwroot = str_replace('http:', 'https:', $CFG->wwwroot);
6128         $CFG->httpsthemewww = str_replace('http:', 'https:', $CFG->themewww);
6129
6130         // change theme URLs to https
6131         theme_setup();
6132
6133     } else {
6134         $CFG->httpswwwroot = $CFG->wwwroot;
6135         $CFG->httpsthemewww = $CFG->themewww;
6136     }
6137 }
6138
6139 /**
6140  * For outputting debugging info
6141  *
6142  * @uses STDOUT
6143  * @param string $string ?
6144  * @param string $eol ?
6145  * @todo Finish documenting this function
6146  */
6147 function mtrace($string, $eol="\n", $sleep=0) {
6148
6149     if (defined('STDOUT')) {
6150         fwrite(STDOUT, $string.$eol);
6151     } else {
6152         echo $string . $eol;
6153     }
6154
6155     flush();
6156
6157     //delay to keep message on user's screen in case of subsequent redirect
6158     if ($sleep) {
6159         sleep($sleep);
6160     }
6161 }
6162
6163 //Replace 1 or more slashes or backslashes to 1 slash
6164 function cleardoubleslashes ($path) {
6165     return preg_replace('/(\/|\\\){1,}/','/',$path);
6166 }
6167
6168 function zip_files ($originalfiles, $destination) {
6169 //Zip an array of files/dirs to a destination zip file
6170 //Both parameters must be FULL paths to the files/dirs
6171
6172     global $CFG;
6173
6174     //Extract everything from destination
6175     $path_parts = pathinfo(cleardoubleslashes($destination));
6176     $destpath = $path_parts["dirname"];       //The path of the zip file
6177     $destfilename = $path_parts["basename"];  //The name of the zip file
6178     $extension = $path_parts["extension"];    //The extension of the file
6179
6180     //If no file, error
6181     if (empty($destfilename)) {
6182         return false;
6183     }
6184
6185     //If no extension, add it
6186     if (empty($extension)) {
6187         $extension = 'zip';
6188         $destfilename = $destfilename.'.'.$extension;
6189     }
6190
6191     //Check destination path exists
6192     if (!is_dir($destpath)) {
6193         return false;
6194     }
6195
6196     //Check destination path is writable. TODO!!
6197
6198     //Clean destination filename
6199     $destfilename = clean_filename($destfilename);
6200
6201     //Now check and prepare every file
6202     $files = array();
6203     $origpath = NULL;
6204
6205     foreach ($originalfiles as $file) {  //Iterate over each file
6206         //Check for every file
6207         $tempfile = cleardoubleslashes($file); // no doubleslashes!
6208         //Calculate the base path for all files if it isn't set
6209         if ($origpath === NULL) {
6210             $origpath = rtrim(cleardoubleslashes(dirname($tempfile)), "/");
6211         }
6212         //See if the file is readable
6213         if (!is_readable($tempfile)) {  //Is readable
6214             continue;
6215         }
6216         //See if the file/dir is in the same directory than the rest
6217         if (rtrim(cleardoubleslashes(dirname($tempfile)), "/") != $origpath) {
6218             continue;
6219         }
6220         //Add the file to the array
6221         $files[] = $tempfile;
6222     }
6223
6224     //Everything is ready:
6225     //    -$origpath is the path where ALL the files to be compressed reside (dir).
6226     //    -$destpath is the destination path where the zip file will go (dir).
6227     //    -$files is an array of files/dirs to compress (fullpath)
6228     //    -$destfilename is the name of the zip file (without path)
6229
6230     //print_object($files);                  //Debug
6231
6232     if (empty($CFG->zip)) {    // Use built-in php-based zip function
6233
6234         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6235         //rewrite filenames because the old method with PCLZIP_OPT_REMOVE_PATH does not work under win32
6236         $zipfiles = array();
6237         $start = strlen($origpath)+1;
6238         foreach($files as $file) {
6239             $tf = array();
6240             $tf[PCLZIP_ATT_FILE_NAME] = $file;
6241             $tf[PCLZIP_ATT_FILE_NEW_FULL_NAME] = substr($file, $start);
6242             $zipfiles[] = $tf;
6243         }
6244         //create the archive
6245         $archive = new PclZip(cleardoubleslashes("$destpath/$destfilename"));
6246         if (($list = $archive->create($zipfiles) == 0)) {
6247             notice($archive->errorInfo(true));
6248             return false;
6249         }
6250
6251     } else {                   // Use external zip program
6252
6253         $filestozip = "";
6254         foreach ($files as $filetozip) {
6255             $filestozip .= escapeshellarg(basename($filetozip));
6256             $filestozip .= " ";
6257         }
6258         //Construct the command
6259         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6260         $command = 'cd '.escapeshellarg($origpath).$separator.
6261                     escapeshellarg($CFG->zip).' -r '.
6262                     escapeshellarg(cleardoubleslashes("$destpath/$destfilename")).' '.$filestozip;
6263         //All converted to backslashes in WIN
6264         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6265             $command = str_replace('/','\\',$command);
6266         }
6267         Exec($command);
6268     }
6269     return true;
6270 }
6271
6272 function unzip_file ($zipfile, $destination = '', $showstatus = true) {
6273 //Unzip one zip file to a destination dir
6274 //Both parameters must be FULL paths
6275 //If destination isn't specified, it will be the
6276 //SAME directory where the zip file resides.
6277
6278     global $CFG;
6279
6280     //Extract everything from zipfile
6281     $path_parts = pathinfo(cleardoubleslashes($zipfile));
6282     $zippath = $path_parts["dirname"];       //The path of the zip file
6283     $zipfilename = $path_parts["basename"];  //The name of the zip file
6284     $extension = $path_parts["extension"];    //The extension of the file
6285
6286     //If no file, error
6287     if (empty($zipfilename)) {
6288         return false;
6289     }
6290
6291     //If no extension, error
6292     if (empty($extension)) {
6293         return false;
6294     }
6295
6296     //Clear $zipfile
6297     $zipfile = cleardoubleslashes($zipfile);
6298
6299     //Check zipfile exists
6300     if (!file_exists($zipfile)) {
6301         return false;
6302     }
6303
6304     //If no destination, passed let's go with the same directory
6305     if (empty($destination)) {
6306         $destination = $zippath;
6307     }
6308
6309     //Clear $destination
6310     $destpath = rtrim(cleardoubleslashes($destination), "/");
6311
6312     //Check destination path exists
6313     if (!is_dir($destpath)) {
6314         return false;
6315     }
6316
6317     //Check destination path is writable. TODO!!
6318
6319     //Everything is ready:
6320     //    -$zippath is the path where the zip file resides (dir)
6321     //    -$zipfilename is the name of the zip file (without path)
6322     //    -$destpath is the destination path where the zip file will uncompressed (dir)
6323
6324     $list = null;
6325
6326     if (empty($CFG->unzip)) {    // Use built-in php-based unzip function
6327
6328         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6329         $archive = new PclZip(cleardoubleslashes("$zippath/$zipfilename"));
6330         if (!$list = $archive->extract(PCLZIP_OPT_PATH, $destpath,
6331                                        PCLZIP_CB_PRE_EXTRACT, 'unzip_cleanfilename',
6332                                        PCLZIP_OPT_EXTRACT_DIR_RESTRICTION, $destpath)) {
6333             notice($archive->errorInfo(true));
6334             return false;
6335         }
6336
6337     } else {                     // Use external unzip program
6338
6339         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6340         $redirection = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? '' : ' 2>&1';
6341
6342         $command = 'cd '.escapeshellarg($zippath).$separator.
6343                     escapeshellarg($CFG->unzip).' -o '.
6344                     escapeshellarg(cleardoubleslashes("$zippath/$zipfilename")).' -d '.
6345                     escapeshellarg($destpath).$redirection;
6346         //All converted to backslashes in WIN
6347         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6348             $command = str_replace('/','\\',$command);
6349         }
6350         Exec($command,$list);
6351     }
6352
6353     //Display some info about the unzip execution
6354     if ($showstatus) {
6355         unzip_show_status($list,$destpath);
6356     }
6357
6358     return true;
6359 }
6360
6361 function unzip_cleanfilename ($p_event, &$p_header) {
6362 //This function is used as callback in unzip_file() function
6363 //to clean illegal characters for given platform and to prevent directory traversal.
6364 //Produces the same result as info-zip unzip.
6365     $p_header['filename'] = ereg_replace('[[:cntrl:]]', '', $p_header['filename']); //strip control chars first!
6366     $p_header['filename'] = ereg_replace('\.\.+', '', $p_header['filename']); //directory traversal protection
6367     if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6368         $p_header['filename'] = ereg_replace('[:*"?<>|]', '_', $p_header['filename']); //replace illegal chars
6369         $p_header['filename'] = ereg_replace('^([a-zA-Z])_', '\1:', $p_header['filename']); //repair drive letter
6370     } else {
6371         //Add filtering for other systems here
6372         // BSD: none (tested)
6373         // Linux: ??
6374         // MacosX: ??
6375     }
6376     $p_header['filename'] = cleardoubleslashes($p_header['filename']); //normalize the slashes/backslashes
6377     return 1;
6378 }
6379
6380 function unzip_show_status ($list,$removepath) {
6381 //This function shows the results of the unzip execution
6382 //depending of the value of the $CFG->zip, results will be
6383 //text or an array of files.
6384
6385     global $CFG;
6386
6387     if (empty($CFG->unzip)) {    // Use built-in php-based zip function
6388         $strname = get_string("name");
6389         $strsize = get_string("size");
6390         $strmodified = get_string("modified");
6391         $strstatus = get_string("status");
6392         echo "<table width=\"640\">";
6393         echo "<tr><th class=\"header\" scope=\"col\">$strname</th>";
6394         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strsize</th>";
6395         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strmodified</th>";
6396         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strstatus</th></tr>";
6397         foreach ($list as $item) {
6398             echo "<tr>";
6399             $item['filename'] = str_replace(cleardoubleslashes($removepath).'/', "", $item['filename']);
6400             print_cell("left", s($item['filename']));
6401             if (! $item['folder']) {
6402                 print_cell("right", display_size($item['size']));
6403             } else {
6404                 echo "<td>&nbsp;</td>";
6405             }
6406             $filedate  = userdate($item['mtime'], get_string("strftimedatetime"));
6407             print_cell("right", $filedate);
6408             print_cell("right", $item['status']);
6409             echo "</tr>";
6410         }
6411         echo "</table>";
6412
6413     } else {                   // Use external zip program
6414         print_simple_box_start("center");
6415         echo "<pre>";
6416         foreach ($list as $item) {
6417             echo s(str_replace(cleardoubleslashes($removepath.'/'), '', $item)).'<br />';
6418         }
6419         echo "</pre>";
6420         print_simple_box_end();
6421     }
6422 }
6423
6424 /**
6425  * Returns most reliable client address
6426  *
6427  * @return string The remote IP address
6428  */
6429  function getremoteaddr() {
6430     if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
6431         return cleanremoteaddr($_SERVER['HTTP_CLIENT_IP']);
6432     }
6433     if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
6434         return cleanremoteaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
6435     }
6436     if (!empty($_SERVER['REMOTE_ADDR'])) {
6437         return cleanremoteaddr($_SERVER['REMOTE_ADDR']);
6438     }
6439     return '';
6440 }
6441
6442 /**
6443  * Cleans a remote address ready to put into the log table
6444  */
6445 function cleanremoteaddr($addr) {
6446     $originaladdr = $addr;
6447     $matches = array();
6448     // first get all things that look like IP addresses.
6449     if (!preg_match_all('/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/',$addr,$matches,PREG_SET_ORDER)) {
6450         return '';
6451     }
6452     $goodmatches = array();
6453     $lanmatches = array();
6454     foreach ($matches as $match) {
6455         //        print_r($match);
6456         // check to make sure it's not an internal address.
6457         // the following are reserved for private lans...
6458         // 10.0.0.0 - 10.255.255.255
6459         // 172.16.0.0 - 172.31.255.255
6460         // 192.168.0.0 - 192.168.255.255
6461         // 169.254.0.0 -169.254.255.255
6462         $bits = explode('.',$match[0]);
6463         if (count($bits) != 4) {
6464             // weird, preg match shouldn't give us it.
6465             continue;
6466         }
6467         if (($bits[0] == 10)
6468             || ($bits[0] == 172 && $bits[1] >= 16 && $bits[1] <= 31)
6469             || ($bits[0] == 192 && $bits[1] == 168)
6470             || ($bits[0] == 169 && $bits[1] == 254)) {
6471             $lanmatches[] = $match[0];
6472             continue;
6473         }
6474         // finally, it's ok
6475         $goodmatches[] = $match[0];
6476     }
6477     if (!count($goodmatches)) {
6478         // perhaps we have a lan match, it's probably better to return that.
6479         if (!count($lanmatches)) {
6480             return '';
6481         } else {
6482             return array_pop($lanmatches);
6483         }
6484     }
6485     if (count($goodmatches) == 1) {
6486         return $goodmatches[0];
6487     }
6488     error_log("NOTICE: cleanremoteaddr gives us something funny: $originaladdr had ".count($goodmatches)." matches");
6489     // we need to return something, so
6490     return array_pop($goodmatches);
6491 }
6492
6493 /**
6494  * file_put_contents is only supported by php 5.0 and higher
6495  * so if it is not predefined, define it here
6496  *
6497  * @param $file full path of the file to write
6498  * @param $contents contents to be sent
6499  * @return number of bytes written (false on error)
6500  */
6501 if(!function_exists('file_put_contents')) {
6502     function file_put_contents($file, $contents) {
6503         $result = false;
6504         if ($f = fopen($file, 'w')) {
6505             $result = fwrite($f, $contents);
6506             fclose($f);
6507         }
6508         return $result;
6509     }
6510 }
6511
6512 /**
6513  * The clone keyword is only supported from PHP 5 onwards.
6514  * The behaviour of $obj2 = $obj1 differs fundamentally
6515  * between PHP 4 and PHP 5. In PHP 4 a copy of $obj1 was
6516  * created, in PHP 5 $obj1 is referenced. To create a copy
6517  * in PHP 5 the clone keyword was introduced. This function
6518  * simulates this behaviour for PHP < 5.0.0.
6519  * See also: http://mjtsai.com/blog/2004/07/15/php-5-object-references/
6520  *
6521  * Modified 2005-09-29 by Eloy (from Julian Sedding proposal)
6522  * Found a better implementation (more checks and possibilities) from PEAR:
6523  * http://cvs.php.net/co.php/pear/PHP_Compat/Compat/Function/clone.php
6524  *
6525  * @param object $obj
6526  * @return object
6527  */
6528 if(!check_php_version('5.0.0')) {
6529 // the eval is needed to prevent PHP 5 from getting a parse error!
6530 eval('
6531     function clone($obj) {
6532     /// Sanity check
6533         if (!is_object($obj)) {
6534             user_error(\'clone() __clone method called on non-object\', E_USER_WARNING);
6535             return;
6536         }
6537
6538     /// Use serialize/unserialize trick to deep copy the object
6539         $obj = unserialize(serialize($obj));
6540
6541     /// If there is a __clone method call it on the "new" class
6542         if (method_exists($obj, \'__clone\')) {
6543             $obj->__clone();
6544         }
6545
6546         return $obj;
6547     }
6548
6549     // Supply the PHP5 function scandir() to older versions.
6550     function scandir($directory) {
6551         $files = array();
6552         if ($dh = opendir($directory)) {
6553             while (($file = readdir($dh)) !== false) {
6554                $files[] = $file;
6555             }
6556             closedir($dh);
6557         }
6558         return $files;
6559     }
6560
6561     // Supply the PHP5 function array_combine() to older versions.
6562     function array_combine($keys, $values) {
6563         if (!is_array($keys) || !is_array($values) || count($keys) != count($values)) {
6564             return false;
6565         }
6566         reset($values);
6567         $result = array();
6568         foreach ($keys as $key) {
6569             $result[$key] = current($values);
6570             next($values);
6571         }
6572         return $result;
6573     }
6574 ');
6575 }
6576
6577 /**
6578  * This function will make a complete copy of anything it's given,
6579  * regardless of whether it's an object or not.
6580  * @param mixed $thing
6581  * @return mixed
6582  */
6583 function fullclone($thing) {
6584     return unserialize(serialize($thing));
6585 }
6586
6587
6588 /*
6589  * This function expects to called during shutdown
6590  * should be set via register_shutdown_function()
6591  * in lib/setup.php .
6592  *
6593  * Right now we do it only if we are under apache, to
6594  * make sure apache children that hog too much mem are
6595  * killed.
6596  *
6597  */
6598 function moodle_request_shutdown() {
6599
6600     global $CFG;
6601
6602     // initially, we are only ever called under apache
6603     // but check just in case
6604     if (function_exists('apache_child_terminate')
6605         && function_exists('memory_get_usage')
6606         && ini_get_bool('child_terminate')) {
6607         if (empty($CFG->apachemaxmem)) {
6608             $CFG->apachemaxmem = 25000000; // default 25MiB
6609         }
6610         if (memory_get_usage() > (int)$CFG->apachemaxmem) {
6611             trigger_error('Mem usage over $CFG->apachemaxmem: marking child for reaping.');
6612             @apache_child_terminate();
6613         }
6614     }
6615 }
6616
6617 /**
6618  * If new messages are waiting for the current user, then return
6619  * Javascript code to create a popup window
6620  *
6621  * @return string Javascript code
6622  */
6623 function message_popup_window() {
6624     global $USER;
6625
6626     $popuplimit = 30;     // Minimum seconds between popups
6627
6628     if (!defined('MESSAGE_WINDOW')) {
6629         if (isset($USER->id)) {
6630             if (!isset($USER->message_lastpopup)) {
6631                 $USER->message_lastpopup = 0;
6632             }
6633             if ((time() - $USER->message_lastpopup) > $popuplimit) {  /// It's been long enough
6634                 if (get_user_preferences('message_showmessagewindow', 1) == 1) {
6635                     if (count_records_select('message', 'useridto = \''.$USER->id.'\' AND timecreated > \''.$USER->message_lastpopup.'\'')) {
6636                         $USER->message_lastpopup = time();
6637                         return '<script type="text/javascript">'."\n//<![CDATA[\n openpopup('/message/index.php', 'message',
6638                         'menubar=0,location=0,scrollbars,status,resizable,width=400,height=500', 0);\n//]]>\n</script>";
6639                     }
6640                 }
6641             }
6642         }
6643     }
6644
6645     return '';
6646 }
6647
6648 // Used to make sure that $min <= $value <= $max
6649 function bounded_number($min, $value, $max) {
6650     if($value < $min) {
6651         return $min;
6652     }
6653     if($value > $max) {
6654         return $max;
6655     }
6656     return $value;
6657 }
6658
6659 function array_is_nested($array) {
6660     foreach ($array as $value) {
6661         if (is_array($value)) {
6662             return true;
6663         }
6664     }
6665     return false;
6666 }
6667
6668 /**
6669  *** get_performance_info() pairs up with init_performance_info()
6670  *** loaded in setup.php. Returns an array with 'html' and 'txt'
6671  *** values ready for use, and each of the individual stats provided
6672  *** separately as well.
6673  ***
6674  **/
6675 function get_performance_info() {
6676     global $CFG, $PERF, $rcache;
6677
6678     $info = array();
6679     $info['html'] = '';         // holds userfriendly HTML representation
6680     $info['txt']  = me() . ' '; // holds log-friendly representation
6681
6682     $info['realtime'] = microtime_diff($PERF->starttime, microtime());
6683
6684     $info['html'] .= '<span class="timeused">'.$info['realtime'].' secs</span> ';
6685     $info['txt'] .= 'time: '.$info['realtime'].'s ';
6686
6687     if (function_exists('memory_get_usage')) {
6688         $info['memory_total'] = memory_get_usage();
6689         $info['memory_growth'] = memory_get_usage() - $PERF->startmemory;
6690         $info['html'] .= '<span class="memoryused">RAM: '.display_size($info['memory_total']).'</span> ';
6691         $info['txt']  .= 'memory_total: '.$info['memory_total'].'B (' . display_size($info['memory_total']).') memory_growth: '.$info['memory_growth'].'B ('.display_size($info['memory_growth']).') ';
6692     }
6693
6694     $inc = get_included_files();
6695     //error_log(print_r($inc,1));
6696     $info['includecount'] = count($inc);
6697     $info['html'] .= '<span class="included">Included '.$info['includecount'].' files</span> ';
6698     $info['txt']  .= 'includecount: '.$info['includecount'].' ';
6699
6700     if (!empty($PERF->dbqueries)) {
6701         $info['dbqueries'] = $PERF->dbqueries;
6702         $info['html'] .= '<span class="dbqueries">DB queries '.$info['dbqueries'].'</span> ';
6703         $info['txt'] .= 'dbqueries: '.$info['dbqueries'].' ';
6704     }
6705
6706     if (!empty($PERF->logwrites)) {
6707         $info['logwrites'] = $PERF->logwrites;
6708         $info['html'] .= '<span class="logwrites">Log writes '.$info['logwrites'].'</span> ';
6709         $info['txt'] .= 'logwrites: '.$info['logwrites'].' ';
6710     }
6711
6712     if (!empty($PERF->profiling) && $PERF->profiling) {
6713         require_once($CFG->dirroot .'/lib/profilerlib.php');
6714         $info['html'] .= '<span class="profilinginfo">'.Profiler::get_profiling(array('-R')).'</span>';
6715     }
6716
6717     if (function_exists('posix_times')) {
6718         $ptimes = posix_times();
6719         if (is_array($ptimes)) {
6720             foreach ($ptimes as $key => $val) {
6721                 $info[$key] = $ptimes[$key] -  $PERF->startposixtimes[$key];
6722             }
6723             $info['html'] .= "<span class=\"posixtimes\">ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime]</span> ";
6724             $info['txt'] .= "ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime] ";
6725         }
6726     }
6727
6728     // Grab the load average for the last minute
6729     // /proc will only work under some linux configurations
6730     // while uptime is there under MacOSX/Darwin and other unices
6731     if (is_readable('/proc/loadavg') && $loadavg = @file('/proc/loadavg')) {
6732         list($server_load) = explode(' ', $loadavg[0]);
6733         unset($loadavg);
6734     } else if ( function_exists('is_executable') && is_executable('/usr/bin/uptime') && $loadavg = `/usr/bin/uptime` ) {
6735         if (preg_match('/load averages?: (\d+[\.,:]\d+)/', $loadavg, $matches)) {
6736             $server_load = $matches[1];
6737         } else {
6738             trigger_error('Could not parse uptime output!');
6739         }
6740     }
6741     if (!empty($server_load)) {
6742         $info['serverload'] = $server_load;
6743         $info['html'] .= '<span class="serverload">Load average: '.$info['serverload'].'</span> ';
6744         $info['txt'] .= "serverload: {$info['serverload']} ";
6745     }
6746
6747     if (isset($rcache->hits) && isset($rcache->misses)) {
6748         $info['rcachehits'] = $rcache->hits;
6749         $info['rcachemisses'] = $rcache->misses;
6750         $info['html'] .= '<span class="rcache">Record cache hit/miss ratio : '.
6751             "{$rcache->hits}/{$rcache->misses}</span> ";
6752         $info['txt'] .= 'rcache: '.
6753             "{$rcache->hits}/{$rcache->misses} ";
6754     }
6755     $info['html'] = '<div class="performanceinfo">'.$info['html'].'</div>';
6756     return $info;
6757 }
6758
6759 function apd_get_profiling() {
6760     return shell_exec('pprofp -u ' . ini_get('apd.dumpdir') . '/pprof.' . getmypid() . '.*');
6761 }
6762
6763 function remove_dir($dir, $content_only=false) {
6764     // if content_only=true then delete all but
6765     // the directory itself
6766
6767     $handle = opendir($dir);
6768     while (false!==($item = readdir($handle))) {
6769         if($item != '.' && $item != '..') {
6770             if(is_dir($dir.'/'.$item)) {
6771                 remove_dir($dir.'/'.$item);
6772             }else{
6773                 unlink($dir.'/'.$item);
6774             }
6775         }
6776     }
6777     closedir($handle);
6778     if ($content_only) {
6779         return true;
6780     }
6781     return rmdir($dir);
6782 }
6783
6784 /**
6785  * Function to check if a directory exists and optionally create it.
6786  *
6787  * @param string absolute directory path
6788  * @param boolean create directory if does not exist
6789  * @param boolean create directory recursively
6790  *
6791  * @return boolean true if directory exists or created
6792  */
6793 function check_dir_exists($dir, $create=false, $recursive=false) {
6794
6795     global $CFG;
6796
6797     $status = true;
6798
6799     if(!is_dir($dir)) {
6800         if (!$create) {
6801             $status = false;
6802         } else {
6803             umask(0000);
6804             if ($recursive) {
6805                 // PHP 5.0 has recursive mkdir parameter, but 4.x does not :-(
6806                 $dir = str_replace('\\', '/', $dir); //windows compatibility
6807                 $dirs = explode('/', $dir);
6808                 $dir = array_shift($dirs).'/'; //skip root or drive letter
6809                 foreach ($dirs as $part) {
6810                     if ($part == '') {
6811                         continue;
6812                     }
6813                     $dir .= $part.'/';
6814                     if (!is_dir($dir)) {
6815                         if (!mkdir($dir, $CFG->directorypermissions)) {
6816                             $status = false;
6817                             break;
6818                         }
6819                     }
6820                 }
6821             } else {
6822                 $status = mkdir($dir, $CFG->directorypermissions);
6823             }
6824         }
6825     }
6826     return $status;
6827 }
6828
6829 function report_session_error() {
6830     global $CFG, $FULLME;
6831
6832     if (empty($CFG->lang)) {
6833         $CFG->lang = "en";
6834     }
6835     // Set up default theme and locale
6836     theme_setup();
6837     moodle_setlocale();
6838
6839     //clear session cookies
6840     setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
6841     setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
6842     //increment database error counters
6843     if (isset($CFG->session_error_counter)) {
6844         set_config('session_error_counter', 1 + $CFG->session_error_counter);
6845     } else {
6846         set_config('session_error_counter', 1);
6847     }
6848     redirect($FULLME, get_string('sessionerroruser2', 'error'), 5);
6849 }
6850
6851
6852 /**
6853  * Detect if an object or a class contains a given property
6854  * will take an actual object or the name of a class
6855  * @param mix $obj Name of class or real object to test
6856  * @param string $property name of property to find
6857  * @return bool true if property exists
6858  */
6859 function object_property_exists( $obj, $property ) {
6860     if (is_string( $obj )) {
6861         $properties = get_class_vars( $obj );
6862     }
6863     else {
6864         $properties = get_object_vars( $obj );
6865     }
6866     return array_key_exists( $property, $properties );
6867 }
6868
6869
6870 /**
6871  * Detect a custom script replacement in the data directory that will
6872  * replace an existing moodle script
6873  * @param string $urlpath path to the original script
6874  * @return string full path name if a custom script exists
6875  * @return bool false if no custom script exists
6876  */
6877 function custom_script_path($urlpath='') {
6878     global $CFG;
6879
6880     // set default $urlpath, if necessary
6881     if (empty($urlpath)) {
6882         $urlpath = qualified_me(); // e.g. http://www.this-server.com/moodle/this-script.php
6883     }
6884
6885     // $urlpath is invalid if it is empty or does not start with the Moodle wwwroot
6886     if (empty($urlpath) or (strpos($urlpath, $CFG->wwwroot) === false )) {
6887         return false;
6888     }
6889
6890     // replace wwwroot with the path to the customscripts folder and clean path
6891     $scriptpath = $CFG->customscripts . clean_param(substr($urlpath, strlen($CFG->wwwroot)), PARAM_PATH);
6892
6893     // remove the query string, if any
6894     if (($strpos = strpos($scriptpath, '?')) !== false) {
6895         $scriptpath = substr($scriptpath, 0, $strpos);
6896     }
6897
6898     // remove trailing slashes, if any
6899     $scriptpath = rtrim($scriptpath, '/\\');
6900
6901     // append index.php, if necessary
6902     if (is_dir($scriptpath)) {
6903         $scriptpath .= '/index.php';
6904     }
6905
6906     // check the custom script exists
6907     if (file_exists($scriptpath)) {
6908         return $scriptpath;
6909     } else {
6910         return false;
6911     }
6912 }
6913
6914 /**
6915  * Wrapper function to load necessary editor scripts
6916  * to $CFG->editorsrc array. Params can be coursei id
6917  * or associative array('courseid' => value, 'name' => 'editorname').
6918  * @uses $CFG
6919  * @param mixed $args Courseid or associative array.
6920  */
6921 function loadeditor($args) {
6922     global $CFG;
6923     include($CFG->libdir .'/editorlib.php');
6924     return editorObject::loadeditor($args);
6925 }
6926
6927 /**
6928  * Returns whether or not the user object is a remote MNET user. This function
6929  * is in moodlelib because it does not rely on loading any of the MNET code.
6930  *
6931  * @param object $user A valid user object
6932  * @return bool        True if the user is from a remote Moodle.
6933  */
6934 function is_mnet_remote_user($user) {
6935     global $CFG;
6936
6937     if (!isset($CFG->mnet_localhost_id)) {
6938         include_once $CFG->dirroot . '/mnet/lib.php';
6939         $env = new mnet_environment();
6940         $env->init();
6941         unset($env);
6942     }
6943
6944     return (!empty($user->mnethostid) && $user->mnethostid != $CFG->mnet_localhost_id);
6945 }
6946
6947 /**
6948  * Checks if a given plugin is in the list of enabled enrolment plugins.
6949  *
6950  * @param string $auth Enrolment plugin.
6951  * @return boolean Whether the plugin is enabled.
6952  */
6953 function is_enabled_enrol($enrol='') {
6954     global $CFG;
6955
6956     // use the global default if not specified
6957     if ($enrol == '') {
6958         $enrol = $CFG->enrol;
6959     }
6960     return in_array($enrol, explode(',', $CFG->enrol_plugins_enabled));
6961 }
6962
6963 /**
6964  * This function will search for browser prefereed languages, setting Moodle
6965  * to use the best one available if $SESSION->lang is undefined
6966  */
6967 function setup_lang_from_browser() {
6968
6969     global $CFG, $SESSION, $USER;
6970
6971     if (!empty($SESSION->lang) or !empty($USER->lang)) {
6972         // Lang is defined in session or user profile, nothing to do
6973         return;
6974     }
6975
6976     if (!isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) { // There isn't list of browser langs, nothing to do
6977         return;
6978     }
6979
6980 /// Extract and clean langs from headers
6981     $rawlangs = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
6982     $rawlangs = str_replace('-', '_', $rawlangs);         // we are using underscores
6983     $rawlangs = explode(',', $rawlangs);                  // Convert to array
6984     $langs = array();
6985
6986     $order = 1.0;
6987     foreach ($rawlangs as $lang) {
6988         if (strpos($lang, ';') === false) {
6989             $langs[(string)$order] = $lang;
6990             $order = $order-0.01;
6991         } else {
6992             $parts = explode(';', $lang);
6993             $pos = strpos($parts[1], '=');
6994             $langs[substr($parts[1], $pos+1)] = $parts[0];
6995         }
6996     }
6997     krsort($langs, SORT_NUMERIC);
6998
6999     $langlist = get_list_of_languages();
7000
7001 /// Look for such langs under standard locations
7002     foreach ($langs as $lang) {
7003         $lang = strtolower(clean_param($lang.'_utf8', PARAM_SAFEDIR)); // clean it properly for include
7004         if (!array_key_exists($lang, $langlist)) {
7005             continue; // language not allowed, try next one
7006         }
7007         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
7008             $SESSION->lang = $lang; /// Lang exists, set it in session
7009             break; /// We have finished. Go out
7010         }
7011     }
7012     return;
7013 }
7014
7015
7016 ////////////////////////////////////////////////////////////////////////////////
7017 /**
7018  * This function will build the navigation string to be used by print_header
7019  * and others
7020  * @uses $CFG
7021  * @uses $THEME
7022  * @param $extrabreadcrumbs - array of associative arrays, keys: name, link, type
7023  * @return $navigation as an object so it can be differentiated from old style
7024  * navigation strings.
7025  */
7026 function build_navigation($extrabreadcrumbs) {
7027     global $CFG, $COURSE;
7028
7029     $navigation = '';
7030
7031     //Site name
7032     if ($site = get_site()) {
7033         $breadcrumbs[] = array('name' => format_string($site->shortname), 'link' => "$CFG->wwwroot/", 'type' => 'home');
7034     }
7035
7036
7037     if ($COURSE) {
7038         if ($COURSE->id != SITEID) {
7039             //Course
7040             $breadcrumbs[] = array('name' => format_string($COURSE->shortname), 'link' => "$CFG->wwwroot/course/view.php?id=$COURSE->id",'type' => 'course');
7041         }
7042     }
7043
7044     //Merge in extra bread crumbs
7045     $breadcrumbs = array_merge($breadcrumbs, $extrabreadcrumbs);
7046
7047     //Construct an unordered list from $breadcrumbs
7048     //Accessibility: heading hidden from visual browsers by default.
7049     $navigation = '<h2 class="accesshide">'.get_string('youarehere','access')."</h2> <ul>\n";
7050     $countcrumb = count($breadcrumbs);
7051
7052     for($i=0;$i<$countcrumb;$i++) {
7053
7054         // Check the link type to see if this link should appear in the trail
7055         if ($breadcrumbs[$i]['type'] == 'activity' && $i+1 < $countcrumb  && ($CFG->hideactivitytypecrumb == 2 || ($CFG->hideactivitytypecrumb == 1 && !has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $course->id))))) {
7056             continue;
7057         }
7058         $navigation .= '<li class="first">';
7059         if ($i > 0) {
7060             $navigation .= get_separator();
7061         }
7062         if ($breadcrumbs[$i]['link'] && $i+1 < $countcrumb) {
7063             $navigation .= "<a onclick=\"this.target='$CFG->framename'\" href=\"{$breadcrumbs[$i]['link']}\">";
7064         }
7065         $navigation .= "{$breadcrumbs[$i]['name']}";
7066         if ($breadcrumbs[$i]['link'] && $i+1 < $countcrumb) {
7067             $navigation .= "</a>";
7068         }
7069
7070         $navigation .= "</li>";
7071     }
7072
7073     $navigation .= "</ul>";
7074
7075     return(array('newnav' => true, 'breadcrumbs' => $navigation));
7076 }
7077
7078 function is_newnav($navigation) {
7079     if (is_array($navigation) && $navigation['newnav']) {
7080         return(true);
7081     } else {
7082         return(false);
7083     }
7084 }
7085
7086 /**
7087  * Checks whether the given variable name is defined as a variable within the given object.
7088  * @note This will NOT work with stdClass objects, which have no class variables.
7089  * @param string $var The variable name
7090  * @param object $object The object to check
7091  * @return boolean
7092  */
7093 function in_object_vars($var, $object)
7094 {
7095     $class_vars = get_class_vars(get_class($object));
7096     $class_vars = array_keys($class_vars);
7097     return in_array($var, $class_vars);
7098 }
7099
7100 // vim:autoindent:expandtab:shiftwidth=4:tabstop=4:tw=140:
7101 ?>