lib/moodlelib.php

   1 <?PHP // $Id$
   2
   3 //
   4 // moodlelib.php
   5 //
   6 // Large collection of useful functions used by many parts of Moodle.
   7 //
   8 // Martin Dougiamas, 2000
   9 //
  10
  11
  12 /// STANDARD WEB PAGE PARTS ///////////////////////////////////////////////////
  13
  14 function print_header ($title="", $heading="", $navigation="", $focus="", $meta="", $cache=true, $button="") {
  15 // $title - appears top of window
  16 // $heading - appears top of page
  17 // $navigation - premade navigation string
  18 // $focus - indicates form element eg  inputform.password
  19 // $meta - meta tags in the header
  20 // $cache - should this page be cacheable?
  21 // $button - code for a button in the top-right
  22     global $USER, $CFG, $THEME;
  23
  24     if (file_exists("$CFG->dirroot/theme/$CFG->theme/styles.css")) {
  25         $styles = "$CFG->wwwroot/theme/$CFG->theme/styles.css";
  26     } else {
  27         $styles = "$CFG->wwwroot/theme/standard/styles.css";
  28     }
  29
  30     if (!$button and $navigation) {
  31         if (isset($USER->id)) {
  32             $button = "<FONT SIZE=2><A HREF=\"$CFG->wwwroot/login/logout.php\">".get_string("logout")."</A></FONT>";
  33         } else {
  34             $button = "<FONT SIZE=2><A HREF=\"$CFG->wwwroot/login\">".get_string("login")."</A></FONT>";
  35         }
  36     }
  37
  38     if (!$cache) {   // Do everything we can to prevent clients and proxies caching
  39         @header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
  40         @header("Pragma: no-cache");
  41         $meta .= "\n<META HTTP-EQUIV=\"Pragma\" CONTENT=\"no-cache\">";
  42         $meta .= "\n<META HTTP-EQUIV=\"Expires\" CONTENT=\"0\">";
  43     }
  44
  45     include ("$CFG->dirroot/theme/$CFG->theme/header.html");
  46 }
  47
  48 function print_footer ($course=NULL) {
  49 // Can provide a course object to make the footer contain a link to
  50 // to the course home page, otherwise the link will go to the site home
  51     global $USER, $CFG, $THEME;
  52
  53     if ($course) {
  54         if ($course == "home") {   // special case for site home page - please do not remove
  55             if (!$dversion = get_field("config", "value", "name", "version")) {
  56                 $dversion = "unknown!";
  57             }
  58             $homelink  = "<P ALIGN=center><A TITLE=\"Version $dversion: Click to visit moodle.com\" HREF=\"http://moodle.com/\">";
  59             $homelink .= "<IMG WIDTH=85 HEIGHT=25 SRC=\"pix/madewithmoodle.gif\" BORDER=0></A></P>";
  60         } else {
  61             $homelink = "<A TARGET=_top HREF=\"$CFG->wwwroot/course/view.php?id=$course->id\">$course->shortname</A>";
  62         }
  63     } else {
  64         $homelink = "<A TARGET=_top HREF=\"$CFG->wwwroot\">".get_string("home")."</A>";
  65     }
  66     if ($USER->realuser) {
  67         if ($realuser = get_record("user", "id", $USER->realuser)) {
  68             $realuserinfo = " [$realuser->firstname $realuser->lastname] ";
  69         }
  70     }
  71     if ($USER->id) {
  72         $loggedinas = $realuserinfo.get_string("loggedinas", "moodle", "$USER->firstname $USER->lastname").
  73                       " (<A HREF=\"$CFG->wwwroot/login/logout.php\">".get_string("logout")."</A>)";
  74     } else {
  75         $loggedinas = get_string("loggedinnot", "moodle").
  76                       " (<A HREF=\"$CFG->wwwroot/login/\">".get_string("login")."</A>)";
  77     }
  78
  79     include ("$CFG->dirroot/theme/$CFG->theme/footer.html");
  80 }
  81
  82 function print_navigation ($navigation) {
  83    global $CFG;
  84
  85    if ($navigation) {
  86        if (! $site = get_site()) {
  87            $site->shortname = get_string("home");;
  88        }
  89        echo "<A TARGET=_top HREF=\"$CFG->wwwroot/\">$site->shortname</A> -> $navigation";
  90    }
  91 }
  92
  93 function print_heading($text, $align="CENTER", $size=3) {
  94     echo "<P ALIGN=\"$align\"><FONT SIZE=\"$size\"><B>$text</B></FONT></P>";
  95 }
  96
  97 function print_continue($link) {
  98     global $HTTP_REFERER;
  99
 100     if (!$link) {
 101         $link = $HTTP_REFERER;
 102     }
 103
 104     print_heading("<A HREF=\"$link\">".get_string("continue")."</A>");
 105 }
 106
 107
 108 function print_simple_box($message, $align="", $width="", $color="#FFFFFF", $padding=5, $border=1) {
 109     print_simple_box_start($align, $width, $color, $padding, $border);
 110     echo "<P>$message</P>";
 111     print_simple_box_end();
 112 }
 113
 114 function print_simple_box_start($align="", $width="", $color="#FFFFFF", $padding=5, $border=1) {
 115     global $THEME;
 116
 117     if ($align) {
 118         $tablealign = "ALIGN=\"$align\"";
 119     }
 120     if ($width) {
 121         $tablewidth = "WIDTH=\"$width\"";
 122         $innertablewidth = "WIDTH=\"100%\"";
 123     }
 124     echo "<TABLE $tablealign $tablewidth BORDER=0 CELLPADDING=\"$border\" CELLSPACING=0>";
 125     echo "<TR><TD BGCOLOR=\"$THEME->borders\">\n";
 126     echo "<TABLE $innertablewidth BORDER=0 CELLPADDING=\"$padding\" CELLSPACING=0><TR><TD BGCOLOR=\"$color\">";
 127 }
 128
 129 function print_simple_box_end() {
 130     echo "</TD></TR></TABLE>";
 131     echo "</TD></TR></TABLE>";
 132 }
 133
 134 function print_single_button($link, $options, $label="OK") {
 135     echo "<FORM ACTION=\"$link\" METHOD=GET>";
 136     if ($options) {
 137         foreach ($options as $name => $value) {
 138             echo "<INPUT TYPE=hidden NAME=\"$name\" VALUE=\"$value\">";
 139         }
 140     }
 141     echo "<INPUT TYPE=submit VALUE=\"$label\"></FORM>";
 142 }
 143
 144 function print_spacer($height=1, $width=1, $br=true) {
 145     global $CFG;
 146     echo "<IMG HEIGHT=\"$height\" WIDTH=\"$width\" SRC=\"$CFG->wwwroot/pix/spacer.gif\" ALT=\"\">";
 147     if ($br) {
 148         echo "<BR>\n";
 149     }
 150 }
 151
 152 function print_user_picture($userid, $courseid, $picture, $large=false, $returnstring=false) {
 153     global $CFG;
 154
 155     $output = "<A HREF=\"$CFG->wwwroot/user/view.php?id=$userid&course=$courseid\">";
 156     if ($large) {
 157         $file = "f1.jpg";
 158         $size = 100;
 159     } else {
 160         $file = "f2.jpg";
 161         $size = 35;
 162     }
 163     if ($picture) {
 164         if (iswindows()) { // Workaround for a PATH_INFO problem on Windows PHP
 165             $output .= "<IMG SRC=\"$CFG->wwwroot/user/pix.php?file=/$userid/$file\" BORDER=0 WIDTH=$size HEIGHT=$size ALT=\"\">";
 166         } else {           // Use this method if possible for better caching
 167             $output .= "<IMG SRC=\"$CFG->wwwroot/user/pix.php/$userid/$file\" BORDER=0 WIDTH=$size HEIGHT=$size ALT=\"\">";
 168         }
 169     } else {
 170         $output .= "<IMG SRC=\"$CFG->wwwroot/user/default/$file\" BORDER=0 WIDTH=$size HEIGHT=$size ALT=\"\">";
 171     }
 172     $output .= "</A>";
 173
 174     if ($returnstring) {
 175         return $output;
 176     } else {
 177         echo $output;
 178     }
 179 }
 180
 181 function print_table($table) {
 182 // Prints a nicely formatted table.
 183 // $table is an object with three properties.
 184 //     $table->head      is an array of heading names.
 185 //     $table->align     is an array of column alignments
 186 //     $table->data[]    is an array of arrays containing the data.
 187 //     $table->width     is an percentage of the page
 188
 189     if ($table->align) {
 190         foreach ($table->align as $key => $aa) {
 191             if ($aa) {
 192                 $align[$key] = "ALIGN=\"$aa\"";
 193             } else {
 194                 $align[$key] = "";
 195             }
 196         }
 197     }
 198
 199     if (!$table->width) {
 200         $table->width = "80%";
 201     }
 202
 203     print_simple_box_start("CENTER", "$table->width", "#FFFFFF", 0);
 204     echo "<TABLE WIDTH=100% BORDER=0 valign=top align=center cellpadding=10 cellspacing=1>\n";
 205
 206     if ($table->head) {
 207         echo "<TR>";
 208         foreach ($table->head as $key => $heading) {
 209             echo "<TH ".$align[$key].">$heading</TH>";
 210         }
 211         echo "</TR>\n";
 212     }
 213
 214     foreach ($table->data as $row) {
 215         echo "<TR VALIGN=TOP>";
 216         foreach ($row as $key => $item) {
 217             echo "<TD ".$align[$key].">$item</TD>";
 218         }
 219         echo "</TR>\n";
 220     }
 221     echo "</TABLE>\n";
 222     print_simple_box_end();
 223
 224     return true;
 225 }
 226
 227 function print_editing_switch($courseid) {
 228     global $CFG, $USER;
 229
 230     if (isteacher($courseid)) {
 231         if ($USER->editing) {
 232             echo "<A HREF=\"$CFG->wwwroot/course/view.php?id=$courseid&edit=off\">Turn editing off</A>";
 233         } else {
 234             echo "<A HREF=\"$CFG->wwwroot/course/view.php?id=$courseid&edit=on\">Turn editing on</A>";
 235         }
 236     }
 237 }
 238
 239 function update_course_icon($courseid) {
 240     global $CFG, $USER;
 241
 242     if (isteacher($courseid)) {
 243         if ($USER->editing) {
 244             return "<A TITLE=\"".get_string("turneditingoff")."\"
 245                     HREF=\"$CFG->wwwroot/course/view.php?id=$courseid&edit=off\"
 246                     TARGET=_top><IMG SRC=\"$CFG->wwwroot/pix/i/edit.gif\" ALIGN=right BORDER=0></A>";
 247         } else {
 248             return "<A TITLE=\"".get_string("turneditingon")."\"
 249                     HREF=\"$CFG->wwwroot/course/view.php?id=$courseid&edit=on\"
 250                     TARGET=_top><IMG SRC=\"$CFG->wwwroot/pix/i/edit.gif\" ALIGN=right BORDER=0></A>";
 251         }
 252     }
 253 }
 254
 255 function update_module_icon($moduleid, $courseid) {
 256     global $CFG;
 257
 258     if (isteacher($courseid)) {
 259         return "<A TITLE=\"".get_string("editthisactivity")."\" HREF=\"$CFG->wwwroot/course/mod.php?update=$moduleid&return=true\" TARGET=_top><IMG SRC=\"$CFG->wwwroot/pix/i/edit.gif\" ALIGN=right BORDER=0></A>";
 260     }
 261 }
 262
 263
 264 function print_date_selector($day, $month, $year, $currenttime=0) {
 265 // Currenttime is a default timestamp in GMT
 266 // Prints form items with the names $day, $month and $year
 267
 268     if (!$currenttime) {
 269         $currenttime = time();
 270     }
 271     $currentdate = usergetdate($currenttime);
 272
 273     for ($i=1; $i<=31; $i++) {
 274         $days[$i] = "$i";
 275     }
 276     for ($i=1; $i<=12; $i++) {
 277         $months[$i] = date("F", mktime(0,0,0,$i,1,2000));
 278     }
 279     for ($i=2000; $i<=2010; $i++) {
 280         $years[$i] = $i;
 281     }
 282     choose_from_menu($days,   $day,   $currentdate[mday], "");
 283     choose_from_menu($months, $month, $currentdate[mon],  "");
 284     choose_from_menu($years,  $year,  $currentdate[year], "");
 285 }
 286
 287 function print_time_selector($hour, $minute, $currenttime=0) {
 288 // Currenttime is a default timestamp in GMT
 289 // Prints form items with the names $hour and $minute
 290
 291     if (!$currenttime) {
 292         $currenttime = time();
 293     }
 294     $currentdate = usergetdate($currenttime);
 295     for ($i=0; $i<=23; $i++) {
 296         $hours[$i] = sprintf("%02d",$i);
 297     }
 298     for ($i=0; $i<=59; $i++) {
 299         $minutes[$i] = sprintf("%02d",$i);
 300     }
 301     choose_from_menu($hours,   $hour,   $currentdate[hours],   "");
 302     choose_from_menu($minutes, $minute, $currentdate[minutes], "");
 303 }
 304
 305 function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0) {
 306 // Given date parts in user time, produce a GMT timestamp
 307
 308    return mktime((int)$hour,(int)$minute,(int)$second,(int)$month,(int)$day,(int)$year);
 309 }
 310
 311 function format_time($totalsecs) {
 312 // Given an amount of time in seconds, prints it
 313 // nicely as months, days, hours etc as needed
 314
 315     $totalsecs = abs($totalsecs);
 316
 317     $days  = floor($totalsecs/86400);
 318     $remainder = $totalsecs - ($days*86400);
 319     $hours = floor($remainder/3600);
 320     $remainder = $remainder - ($hours*3600);
 321     $mins  = floor($remainder/60);
 322     $secs = $remainder - ($mins*60);
 323
 324     if ($secs  != 1) $ss = "s";
 325     if ($mins  != 1) $ms = "s";
 326     if ($hours != 1) $hs = "s";
 327     if ($days  != 1) $ds = "s";
 328
 329     if ($days)  $odays  = "$days day$ds";
 330     if ($hours) $ohours = "$hours hr$hs";
 331     if ($mins)  $omins  = "$mins min$ms";
 332     if ($secs)  $osecs  = "$secs sec$ss";
 333
 334     if ($days)  return "$odays $ohours";
 335     if ($hours) return "$ohours $omins";
 336     if ($mins)  return "$omins $osecs";
 337     if ($secs)  return "$osecs";
 338     return get_string("now");
 339 }
 340
 341 function userdate($date, $format="", $timezone=99) {
 342 // Returns a formatted string that represents a date in user time
 343 // WARNING: note that the format is for strftime(), not date().
 344
 345     global $USER;
 346
 347     if ($format == "") {
 348         $format = "%A, %e %B %Y, %I:%M %p";
 349     }
 350     if ($timezone == 99) {
 351         if (isset($USER->timezone)) {
 352             $timezone = (float)$USER->timezone;
 353         }
 354     }
 355     if (abs($timezone) > 12) {
 356         return strftime("$format", $date);
 357     }
 358     return gmstrftime($format, $date + (int)($timezone * 3600));
 359 }
 360
 361 function usergetdate($date, $timezone=99) {
 362 // Given a $date timestamp in GMT, returns an array
 363 // that represents the date in user time
 364
 365     global $USER;
 366
 367     if ($timezone == 99) {
 368         $timezone = (float)$USER->timezone;
 369     }
 370     if (abs($timezone) > 12) {
 371         return getdate($date);
 372     }
 373     //There is no gmgetdate so I have to fake it...
 374     $date = $date + (int)($timezone * 3600);
 375     $getdate["seconds"] = gmstrftime("%S", $date);
 376     $getdate["minutes"] = gmstrftime("%M", $date);
 377     $getdate["hours"]   = gmstrftime("%H", $date);
 378     $getdate["mday"]    = gmstrftime("%d", $date);
 379     $getdate["wday"]    = gmstrftime("%u", $date);
 380     $getdate["mon"]     = gmstrftime("%m", $date);
 381     $getdate["year"]    = gmstrftime("%Y", $date);
 382     $getdate["yday"]    = gmstrftime("%j", $date);
 383     $getdate["weekday"] = gmstrftime("%A", $date);
 384     $getdate["month"]   = gmstrftime("%B", $date);
 385     return $getdate;
 386 }
 387
 388 function usertime($date, $timezone=99) {
 389 // Given a GMT timestamp (seconds since epoch), offsets it by
 390 // the timezone.  eg 3pm in India is 3pm GMT - 7 * 3600 seconds
 391     global $USER;
 392
 393     if ($timezone == 99) {
 394         $timezone = (float)$USER->timezone;
 395     }
 396     if (abs($timezone) > 12) {
 397         return $date;
 398     }
 399     return $date - (int)($timezone * 3600);
 400 }
 401
 402 function usergetmidnight($date, $timezone=99) {
 403 // Given a time, return the GMT timestamp of the most recent midnight
 404 // for the current user.
 405     global $USER;
 406
 407     if ($timezone == 99) {
 408         $timezone = (float)$USER->timezone;
 409     }
 410
 411     $userdate = usergetdate($date, $timezone);
 412
 413     if (abs($timezone) > 12) {
 414         return mktime(0, 0, 0, $userdate["mon"], $userdate["mday"], $userdate["year"]);
 415     }
 416
 417     $timemidnight = gmmktime (0, 0, 0, $userdate["mon"], $userdate["mday"], $userdate["year"]);
 418     return usertime($timemidnight, $timezone); // Time of midnight of this user's day, in GMT
 419
 420 }
 421
 422 function usertimezone($timezone=99) {
 423 // returns a string that prints the user's timezone
 424     global $USER;
 425
 426     if ($timezone == 99) {
 427         $timezone = (float)$USER->timezone;
 428     }
 429     if (abs($timezone) > 12) {
 430         return "server time";
 431     }
 432     if (abs($timezone) < 0.5) {
 433         return "GMT";
 434     }
 435     if ($timezone > 0) {
 436         return "GMT+$timezone";
 437     } else {
 438         return "GMT$timezone";
 439     }
 440 }
 441
 442
 443 function error ($message, $link="") {
 444     global $CFG, $SESSION;
 445
 446     print_header(get_string("error"));
 447     echo "<BR>";
 448     print_simple_box($message, "center", "", "#FFBBBB");
 449
 450     if (!$link) {
 451         if ( !empty($SESSION->fromurl) ) {
 452             $link = "$SESSION->fromurl";
 453             unset($SESSION->fromurl);
 454             save_session("SESSION");
 455         } else {
 456             $link = "$CFG->wwwroot";
 457         }
 458     }
 459     print_continue($link);
 460     print_footer();
 461     die;
 462 }
 463
 464 function helpbutton ($page, $title="", $module="moodle", $image=true, $text="") {
 465     // $page = the keyword that defines a help page
 466     // $title = the title of links, rollover tips, alt tags etc
 467     // $module = which module is the page defined in
 468     // $image = use a help image for the link?  (otherwise uses text)
 469     // $text = if defined then this text is used in the page, and
 470     //         the $page variable is ignored.
 471     global $CFG;
 472     if ($module == "") {
 473         $module = "moodle";
 474     }
 475     if ($image) {
 476         $linkobject = "<IMG BORDER=0 ALT=\"$title\" SRC=\"$CFG->wwwroot/pix/help.gif\">";
 477     } else {
 478         $linkobject = $title;
 479     }
 480     if ($text) {
 481         $url = "/help.php?module=$module&text=$text";
 482     } else {
 483         $url = "/help.php?module=$module&file=$page.html";
 484     }
 485     link_to_popup_window ($url, "popup", $linkobject, 400, 500, $title);
 486 }
 487
 488 function notice ($message, $link="") {
 489     global $THEME, $HTTP_REFERER;
 490
 491     if (!$link) {
 492         $link = $HTTP_REFERER;
 493     }
 494
 495     echo "<BR>";
 496     print_simple_box($message, "center", "", "$THEME->cellheading");
 497     print_heading("<A HREF=\"$link\">".get_string("continue")."</A>");
 498     print_footer();
 499     die;
 500 }
 501
 502 function notice_yesno ($message, $linkyes, $linkno) {
 503     global $THEME;
 504
 505     print_simple_box_start("center", "", "$THEME->cellheading");
 506     echo "<P ALIGN=CENTER><FONT SIZE=3>$message</FONT></P>";
 507     echo "<P ALIGN=CENTER><FONT SIZE=3><B>";
 508     echo "<A HREF=\"$linkyes\">".get_string("yes")."</A>";
 509     echo "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
 510     echo "<A HREF=\"$linkno\">".get_string("no")."</A>";
 511     echo "</B></FONT></P>";
 512     print_simple_box_end();
 513 }
 514
 515 function redirect($url, $message="", $delay=0) {
 516 // Uses META tags to redirect the user, after printing a notice
 517
 518     echo "<META HTTP-EQUIV='Refresh' CONTENT='$delay; URL=$url'>";
 519
 520     if (!empty($message)) {
 521         print_header();
 522         echo "<CENTER>";
 523         echo "<P>$message</P>";
 524         echo "<P>( <A HREF=\"$url\">".get_string("continue")."</A> )</P>";
 525         echo "</CENTER>";
 526     }
 527     die;
 528 }
 529
 530 function notify ($message) {
 531     echo "<P align=center><B><FONT COLOR=#FF0000>$message</FONT></B></P>\n";
 532 }
 533
 534
 535
 536 /// PARAMETER HANDLING ////////////////////////////////////////////////////
 537
 538 function require_variable($var) {
 539     if (! isset($var)) {
 540         error("A required parameter was missing");
 541     }
 542 }
 543
 544 function optional_variable(&$var, $default=0) {
 545     if (! isset($var)) {
 546         $var = $default;
 547     }
 548 }
 549
 550
 551
 552
 553 /// DATABASE HANDLING ////////////////////////////////////////////////
 554
 555 function execute_sql($command) {
 556 // Completely general
 557
 558     global $db;
 559
 560     $result = $db->Execute("$command");
 561
 562     if ($result) {
 563         echo "<P><FONT COLOR=green><B>".get_string("success")."</B></FONT></P>";
 564         return true;
 565     } else {
 566         echo "<P><FONT COLOR=red><B>".get_string("error")."</B></FONT></P>";
 567         return false;
 568     }
 569 }
 570
 571 function modify_database($sqlfile) {
 572 // Assumes that the input text file consists of a number
 573 // of SQL statements ENDING WITH SEMICOLONS.  The semicolons
 574 // MUST be the last character in a line.
 575 // Lines that are blank or that start with "#" are ignored.
 576 // Only tested with mysql dump files (mysqldump -p -d moodle)
 577
 578
 579     if (file_exists($sqlfile)) {
 580         $success = true;
 581         $lines = file($sqlfile);
 582         $command = "";
 583
 584         while ( list($i, $line) = each($lines) ) {
 585             $line = chop($line);
 586             $length = strlen($line);
 587
 588             if ($length  &&  substr($line, 0, 1) <> "#") {
 589                 if (substr($line, $length-1, 1) == ";") {
 590                     $line = substr($line, 0, $length-1);   // strip ;
 591                     $command .= $line;
 592                     if (! execute_sql($command)) {
 593                         $success = false;
 594                     }
 595                     $command = "";
 596                 } else {
 597                     $command .= $line;
 598                 }
 599             }
 600         }
 601
 602     } else {
 603         $success = false;
 604         echo "<P>Tried to modify database, but \"$sqlfile\" doesn't exist!</P>";
 605     }
 606
 607     return $success;
 608 }
 609
 610
 611 function record_exists($table, $field, $value) {
 612     global $db;
 613
 614     $rs = $db->Execute("SELECT * FROM $table WHERE $field = '$value' LIMIT 1");
 615     if (!$rs) return false;
 616
 617     if ( $rs->RecordCount() ) {
 618         return true;
 619     } else {
 620         return false;
 621     }
 622 }
 623
 624 function record_exists_sql($sql) {
 625     global $db;
 626
 627     $rs = $db->Execute($sql);
 628     if (!$rs) return false;
 629
 630     if ( $rs->RecordCount() ) {
 631         return true;
 632     } else {
 633         return false;
 634     }
 635 }
 636
 637
 638 function count_records($table, $selector, $value) {
 639 // Get all the records and count them
 640     global $db;
 641
 642     $rs = $db->Execute("SELECT COUNT(*) FROM $table WHERE $selector = '$value'");
 643     if (!$rs) return 0;
 644
 645     return $rs->fields[0];
 646 }
 647
 648 function count_records_sql($sql) {
 649 // Get all the records and count them
 650     global $db;
 651
 652     $rs = $db->Execute("$sql");
 653     if (!$rs) return 0;
 654
 655     return $rs->fields[0];
 656 }
 657
 658 function get_record($table, $selector, $value) {
 659 // Get a single record as an object
 660     global $db;
 661
 662     $rs = $db->Execute("SELECT * FROM $table WHERE $selector = '$value'");
 663     if (!$rs) return false;
 664
 665     if ( $rs->RecordCount() == 1 ) {
 666         return (object)$rs->fields;
 667     } else {
 668         return false;
 669     }
 670 }
 671
 672 function get_record_sql($sql) {
 673 // Get a single record as an object
 674 // The sql statement is provided as a string.
 675
 676     global $db;
 677
 678     $rs = $db->Execute("$sql");
 679     if (!$rs) return false;
 680
 681     if ( $rs->RecordCount() == 1 ) {
 682         return (object)$rs->fields;
 683     } else {
 684         return false;
 685     }
 686 }
 687
 688 function get_records($table, $selector, $value, $sort="") {
 689 // Get a number of records as an array of objects
 690 // Can optionally be sorted eg "time ASC" or "time DESC"
 691 // The "key" is the first column returned, eg usually "id"
 692     global $db;
 693
 694     if ($sort) {
 695         $sortorder = "ORDER BY $sort";
 696     }
 697     $sql = "SELECT * FROM $table WHERE $selector = '$value' $sortorder";
 698
 699     return get_records_sql($sql);
 700 }
 701
 702 function get_records_sql($sql) {
 703 // Get a number of records as an array of objects
 704 // The "key" is the first column returned, eg usually "id"
 705 // The sql statement is provided as a string.
 706
 707     global $db;
 708
 709     $rs = $db->Execute("$sql");
 710     if (!$rs) return false;
 711
 712     if ( $rs->RecordCount() > 0 ) {
 713         if ($records = $rs->GetAssoc(true)) {
 714             foreach ($records as $key => $record) {
 715                 $objects[$key] = (object) $record;
 716             }
 717             return $objects;
 718         } else {
 719             return false;
 720         }
 721     } else {
 722         return false;
 723     }
 724 }
 725
 726 function get_records_sql_menu($sql) {
 727 // Given an SQL select, this function returns an associative
 728 // array of the first two columns.  This is most useful in
 729 // combination with the choose_from_menu function to create
 730 // a form menu.
 731
 732     global $db;
 733
 734     $rs = $db->Execute("$sql");
 735     if (!$rs) return false;
 736
 737     if ( $rs->RecordCount() > 0 ) {
 738         while (!$rs->EOF) {
 739             $menu[$rs->fields[0]] = $rs->fields[1];
 740             $rs->MoveNext();
 741         }
 742         return $menu;
 743
 744     } else {
 745         return false;
 746     }
 747 }
 748
 749 function get_field($table, $field, $selector, $value) {
 750     global $db;
 751
 752     $rs = $db->Execute("SELECT $field FROM $table WHERE $selector = '$value'");
 753     if (!$rs) return false;
 754
 755     if ( $rs->RecordCount() == 1 ) {
 756         return $rs->fields["$field"];
 757     } else {
 758         return false;
 759     }
 760 }
 761
 762 function set_field($table, $field, $newvalue, $selector, $value) {
 763     global $db;
 764
 765     return $db->Execute("UPDATE $table SET $field = '$newvalue' WHERE $selector = '$value'");
 766 }
 767
 768
 769 function delete_records($table, $selector, $value) {
 770 // Delete one or more records from a table
 771     global $db;
 772
 773     return $db->Execute("DELETE FROM $table WHERE $selector = '$value'");
 774 }
 775
 776 function insert_record($table, $dataobject) {
 777 // Insert a record into a table and return the "id" field
 778 // $dataobject is an object containing needed data
 779
 780     global $db;
 781
 782     // Determine all the fields needed
 783     if (! $columns = $db->MetaColumns("$table")) {
 784         return false;
 785     }
 786
 787     $data = (array)$dataobject;
 788
 789     // Pull out data matching these fields
 790     foreach ($columns as $column) {
 791         if ($column->name <> "id" && isset($data[$column->name]) ) {
 792             $ddd[$column->name] = $data[$column->name];
 793         }
 794     }
 795
 796     // Construct SQL queries
 797     if (! $numddd = count($ddd)) {
 798         return 0;
 799     }
 800
 801     $count = 0;
 802     $insert = "";
 803     $select = "";
 804
 805     foreach ($ddd as $key => $value) {
 806         $count++;
 807         $insert .= "$key = '$value'";
 808         $select .= "$key = '$value'";
 809         if ($count < $numddd) {
 810             $insert .= ", ";
 811             $select .= " AND ";
 812         }
 813     }
 814
 815     if (! $rs = $db->Execute("INSERT INTO $table SET $insert")) {
 816         return false;
 817     }
 818
 819     // Pull it out again to find the id.  This is the most cross-platform method.
 820     if ($rs = $db->Execute("SELECT id FROM $table WHERE $select")) {
 821         return $rs->fields[0];
 822     } else {
 823         return false;
 824     }
 825 }
 826
 827
 828 function update_record($table, $dataobject) {
 829 // Update a record in a table
 830 // $dataobject is an object containing needed data
 831
 832     global $db;
 833
 834     if (! isset($dataobject->id) ) {
 835         return false;
 836     }
 837
 838     // Determine all the fields in the table
 839     if (!$columns = $db->MetaColumns($table)) {
 840         return false;
 841     }
 842     $data = (array)$dataobject;
 843
 844     // Pull out data matching these fields
 845     foreach ($columns as $column) {
 846         if ($column->name <> "id" && isset($data[$column->name]) ) {
 847             $ddd[$column->name] = $data[$column->name];
 848         }
 849     }
 850
 851     // Construct SQL queries
 852     $numddd = count($ddd);
 853     $count = 0;
 854     $update = "";
 855
 856     foreach ($ddd as $key => $value) {
 857         $count++;
 858         $update .= "$key = '$value'";
 859         if ($count < $numddd) {
 860             $update .= ", ";
 861         }
 862     }
 863
 864     if ($rs = $db->Execute("UPDATE $table SET $update WHERE id = '$dataobject->id'")) {
 865         return true;
 866     } else {
 867         return false;
 868     }
 869 }
 870
 871
 872 function print_object($object) {
 873 // Mostly just for debugging
 874
 875     $array = (array)$object;
 876     foreach ($array as $key => $item) {
 877         echo "$key -> $item <BR>";
 878     }
 879 }
 880
 881
 882
 883 /// USER DATABASE ////////////////////////////////////////////////
 884
 885 function get_user_info_from_db($field, $value) {
 886
 887     global $db;
 888
 889     if (!$field || !$value)
 890         return false;
 891
 892     $result = $db->Execute("SELECT * FROM user WHERE $field = '$value'");
 893
 894     if ( $result->RecordCount() == 1 ) {
 895         $user = (object)$result->fields;
 896
 897         $rs = $db->Execute("SELECT course FROM user_students WHERE user = '$user->id' ");
 898         while (!$rs->EOF) {
 899             $course = $rs->fields["course"];
 900             $user->student["$course"] = true;
 901             $rs->MoveNext();
 902         }
 903
 904         $rs = $db->Execute("SELECT course FROM user_teachers WHERE user = '$user->id' ");
 905         while (!$rs->EOF) {
 906             $course = $rs->fields["course"];
 907             $user->teacher["$course"] = true;
 908             $rs->MoveNext();
 909         }
 910
 911         $rs = $db->Execute("SELECT * FROM user_admins WHERE user = '$user->id' ");
 912         while (!$rs->EOF) {
 913             $user->admin = true;
 914             $rs->MoveNext();
 915         }
 916
 917         if ($course = get_site()) {
 918             // Everyone is always a member of the top course
 919             $user->student["$course->id"] = true;
 920         }
 921
 922         return $user;
 923
 924     } else {
 925         return false;
 926     }
 927 }
 928
 929 function update_user_in_db() {
 930
 931    global $db, $USER, $REMOTE_ADDR;
 932
 933    if (!isset($USER->id))
 934        return false;
 935
 936    $timenow = time();
 937    if ($db->Execute("UPDATE LOW_PRIORITY user SET lastIP='$REMOTE_ADDR', lastaccess='$timenow'
 938                                                WHERE id = '$USER->id' ")) {
 939        return true;
 940    } else {
 941        return false;
 942    }
 943 }
 944
 945 function require_login($courseid=0) {
 946 // This function checks that the current user is logged in, and optionally
 947 // whether they are "logged in" or allowed to be in a particular course.
 948 // If not, then it redirects them to the site login or course enrolment.
 949
 950     global $CFG, $SESSION, $USER, $FULLME, $HTTP_REFERER, $PHPSESSID;
 951
 952     // First check that the user is logged in to the site.
 953
 954     if (! (isset($USER->loggedin) and $USER->confirmed) ) { // They're not
 955         $SESSION->wantsurl = $FULLME;
 956         $SESSION->fromurl  = $HTTP_REFERER;
 957         save_session("SESSION");
 958         if ($PHPSESSID) { // Cookies not enabled.
 959             redirect("$CFG->wwwroot/login/?PHPSESSID=$PHPSESSID");
 960         } else {
 961             redirect("$CFG->wwwroot/login/");
 962         }
 963         die;
 964     }
 965
 966     // Next, check if the user can be in a particular course
 967     if ($courseid) {
 968         if ($USER->student[$courseid] || $USER->teacher[$courseid] || $USER->admin) {
 969             if (!isset($USER->realuser)) {  // Don't update if this isn't a realuser
 970                 update_user_in_db();
 971             }
 972             return;   // user is a member of this course.
 973         }
 974         if (! $course = get_record("course", "id", $courseid)) {
 975             error("That course doesn't exist");
 976         }
 977         if ($USER->username == "guest") {
 978             switch ($course->guest) {
 979                 case 0: // Guests not allowed
 980                     print_header();
 981                     notice(get_string("guestsnotallowed", "", $course->fullname));
 982                     break;
 983                 case 1: // Guests allowed
 984                     update_user_in_db();
 985                     return;
 986                 case 2: // Guests allowed with key (drop through)
 987                     break;
 988             }
 989         }
 990
 991         // Currently not enrolled in the course, so see if they want to enrol
 992         $SESSION->wantsurl = $FULLME;
 993         save_session("SESSION");
 994         redirect("$CFG->wwwroot/course/enrol.php?id=$courseid");
 995         die;
 996     }
 997 }
 998
 999
1000
1001 function update_login_count() {
1002     global $SESSION;
1003
1004     $max_logins = 10;
1005
1006     if (empty($SESSION->logincount)) {
1007         $SESSION->logincount = 1;
1008     } else {
1009         $SESSION->logincount++;
1010     }
1011     save_session("SESSION");
1012
1013     if ($SESSION->logincount > $max_logins) {
1014         unset($SESSION->wantsurl);
1015         save_session("SESSION");
1016         error("Sorry, you have exceeded the allowed number of login attempts. Restart your browser.");
1017     }
1018 }
1019
1020
1021 function isadmin($userid=0) {
1022     global $USER;
1023
1024     if (!$userid) {
1025         return $USER->admin;
1026     }
1027
1028     return record_exists_sql("SELECT * FROM user_admins WHERE user='$userid'");
1029 }
1030
1031 function isteacher($courseid, $userid=0) {
1032     global $USER;
1033
1034     if (isadmin($userid)) {  // admins can do anything the teacher can
1035         return true;
1036     }
1037
1038     if (!$userid) {
1039         return $USER->teacher[$courseid];
1040     }
1041
1042     return record_exists_sql("SELECT * FROM user_teachers WHERE user='$userid' AND course='$courseid'");
1043 }
1044
1045
1046 function isstudent($courseid, $userid=0) {
1047     global $USER;
1048
1049     if (!$userid) {
1050         return $USER->student[$courseid];
1051     }
1052
1053     $timenow = time();   // todo:  add time check below
1054
1055     return record_exists_sql("SELECT * FROM user_students WHERE user='$userid' AND course='$courseid'");
1056 }
1057
1058 function isguest($userid=0) {
1059     global $USER;
1060
1061     if (!$userid) {
1062         return ($USER->username == "guest");
1063     }
1064
1065     return record_exists_sql("SELECT * FROM user WHERE id='$userid' AND username = 'guest' ");
1066 }
1067
1068 function isediting($courseid, $user=NULL) {
1069     global $USER;
1070     if (!$user){
1071         $user = $USER;
1072     }
1073     return ($user->editing and isteacher($courseid, $user->id));
1074 }
1075
1076 function reset_login_count() {
1077     global $SESSION;
1078
1079     $SESSION->logincount = 0;
1080     save_session("SESSION");
1081 }
1082
1083
1084 function set_moodle_cookie($thing) {
1085
1086     $days = 60;
1087     $seconds = 60*60*24*$days;
1088
1089     setCookie ('MOODLEID', "", time() - 3600, "/");
1090     setCookie ('MOODLEID', rc4encrypt($thing), time()+$seconds, "/");
1091 }
1092
1093
1094 function get_moodle_cookie() {
1095     global $MOODLEID;
1096     return rc4decrypt($MOODLEID);
1097 }
1098
1099
1100 function save_session($VAR) {
1101 // Copies temporary session variable to permanent sesson variable
1102 // eg $_SESSION["USER"] = $USER;
1103     global $$VAR;
1104     $_SESSION[$VAR] = $$VAR;
1105 }
1106
1107
1108 function verify_login($username, $password) {
1109
1110     $user = get_user_info_from_db("username", $username);
1111
1112     if (! $user) {
1113         return false;
1114     } else if ( $user->password == md5($password) ) {
1115         return $user;
1116     } else {
1117         return false;
1118     }
1119 }
1120
1121 function get_site () {
1122 // Returns $course object of the top-level site.
1123     if ( $course = get_record("course", "category", 0)) {
1124         return $course;
1125     } else {
1126         return false;
1127     }
1128 }
1129
1130 function get_admin () {
1131 // Returns $user object of the main admin user
1132
1133     if ( $admins = get_records_sql("SELECT u.* FROM user u, user_admins a WHERE a.user = u.id ORDER BY u.id ASC")) {
1134         foreach ($admins as $admin) {
1135             return $admin;   // ie the first one (yeah I know it's bodgy)
1136         }
1137     } else {
1138         return false;
1139     }
1140 }
1141
1142 function get_teacher($courseid) {
1143 // Returns $user object of the main teacher for a course
1144     if ( $teachers = get_records_sql("SELECT u.* FROM user u, user_teachers t
1145                                       WHERE t.user = u.id AND t.course = '$courseid'
1146                                       ORDER BY t.authority ASC")) {
1147         foreach ($teachers as $teacher) {
1148             return $teacher;   // ie the first one (yeah I know it's bodgy)
1149         }
1150     } else {
1151         return false;
1152     }
1153 }
1154
1155 function get_course_students($courseid, $sort="u.lastaccess DESC") {
1156     return get_records_sql("SELECT u.* FROM user u, user_students s
1157                             WHERE s.course = '$courseid' AND s.user = u.id
1158                             ORDER BY $sort");
1159 }
1160
1161 function get_course_teachers($courseid, $sort="t.authority ASC") {
1162     return get_records_sql("SELECT u.* FROM user u, user_teachers t
1163                             WHERE t.course = '$courseid' AND t.user = u.id
1164                             ORDER BY $sort");
1165 }
1166
1167 function get_course_users($courseid, $sort="u.lastaccess DESC") {
1168 // Using this method because the direct SQL just would not always work!
1169
1170     $teachers = get_course_teachers($courseid, $sort);
1171     $students = get_course_students($courseid, $sort);
1172
1173     if ($teachers and $students) {
1174         return array_merge($teachers, $students);
1175     } else if ($teachers) {
1176         return $teachers;
1177     } else {
1178         return $students;
1179     }
1180
1181 //    return get_records_sql("SELECT u.* FROM user u, user_students s, user_teachers t
1182 //                            WHERE (s.course = '$courseid' AND s.user = u.id) OR
1183 //                                  (t.course = '$courseid' AND t.user = u.id)
1184 //                            ORDER BY $sort");
1185 }
1186
1187
1188
1189 /// MODULE FUNCTIONS /////////////////////////////////////////////////
1190
1191 function get_coursemodule_from_instance($modulename, $instance, $courseid) {
1192 // Given an instance of a module, finds the coursemodule description
1193
1194     return get_record_sql("SELECT cm.*, m.name
1195                            FROM course_modules cm, modules md, $modulename m
1196                            WHERE cm.course = '$courseid' AND
1197                                  cm.deleted = '0' AND
1198                                  cm.instance = m.id AND
1199                                  md.name = '$modulename' AND
1200                                  md.id = cm.module AND
1201                                  m.id = '$instance'");
1202
1203 }
1204
1205 function get_all_instances_in_course($modulename, $courseid, $sort="cw.section") {
1206 // Returns an array of all the active instances of a particular
1207 // module in a given course.   Returns false on any errors.
1208
1209     return get_records_sql("SELECT m.*,cw.section,cm.id as coursemodule
1210                             FROM course_modules cm, course_sections cw, modules md, $modulename m
1211                             WHERE cm.course = '$courseid' AND
1212                                   cm.instance = m.id AND
1213                                   cm.deleted = '0' AND
1214                                   cm.section = cw.id AND
1215                                   md.name = '$modulename' AND
1216                                   md.id = cm.module
1217                             ORDER BY $sort");
1218
1219 }
1220
1221
1222
1223
1224 /// CORRESPONDENCE  ////////////////////////////////////////////////
1225
1226 function email_to_user($user, $from, $subject, $messagetext, $messagehtml="", $attachment="", $attachname="") {
1227 //  user        - a user record as an object
1228 //  from        - a user record as an object
1229 //  subject     - plain text subject line of the email
1230 //  messagetext - plain text version of the message
1231 //  messagehtml - complete html version of the message (optional)
1232 //  attachment  - a file on the filesystem, relative to $CFG->dataroot
1233 //  attachname  - the name of the file (extension indicates MIME)
1234
1235     global $CFG, $_SERVER;
1236
1237     include_once("$CFG->libdir/phpmailer/class.phpmailer.php");
1238
1239     if (!$user) {
1240         return false;
1241     }
1242
1243     $mail = new phpmailer;
1244
1245     $mail->Version = "Moodle $CFG->moodleversion";     // mailer version
1246     $mail->PluginDir = "$CFG->libdir/phpmailer/";      // plugin directory (eg smtp plugin)
1247     if ($CFG->smtphosts) {
1248         $mail->IsSMTP();                               // use SMTP directly
1249         $mail->Host = "$CFG->smtphosts";               // specify main and backup servers
1250     } else {
1251         $mail->IsMail();                               // use PHP mail() = sendmail
1252     }
1253
1254     $mail->From     = "$from->email";
1255     $mail->FromName = "$from->firstname $from->lastname";
1256     $mail->Subject  =  stripslashes($subject);
1257
1258     $mail->AddAddress("$user->email", "$user->firstname $user->lastname");
1259
1260     $mail->WordWrap = 70;                               // set word wrap
1261
1262     if ($messagehtml) {
1263         $mail->IsHTML(true);
1264         $mail->Body    =  $messagehtml;
1265         $mail->AltBody =  "\n$messagetext\n";
1266     } else {
1267         $mail->IsHTML(false);
1268         $mail->Body =  "\n$messagetext\n";
1269     }
1270
1271     if ($attachment && $attachname) {
1272         if (ereg( "\\.\\." ,$attachment )) {    // Security check for ".." in dir path
1273             $adminuser = get_admin();
1274             $mail->AddAddress("$adminuser->email", "$adminuser->firstname $adminuser->lastname");
1275             $mail->AddStringAttachment("Error in attachment.  User attempted to attach a filename with a unsafe name.", "error.txt", "8bit", "text/plain");
1276         } else {
1277             include_once("$CFG->dirroot/files/mimetypes.php");
1278             $mimetype = mimeinfo("type", $attachname);
1279             $mail->AddAttachment("$CFG->dataroot/$attachment", "$attachname", "base64", "$mimetype");
1280         }
1281     }
1282
1283     if ($mail->Send()) {
1284         return true;
1285     } else {
1286         echo "ERROR: $mail->ErrorInfo\n";
1287         $site = get_site();
1288         add_to_log($site->id, "library", "mailer", $_SERVER["REQUEST_URI"], "ERROR: $mail->ErrorInfo");
1289         return false;
1290     }
1291 }
1292
1293
1294 /// FILE HANDLING  /////////////////////////////////////////////
1295
1296 function make_upload_directory($directory) {
1297 // $directory = a string of directory names under $CFG->dataroot
1298 // eg  stuff/assignment/1
1299 // Returns full directory if successful, false if not
1300
1301     global $CFG;
1302
1303     $currdir = $CFG->dataroot;
1304     if (!file_exists($currdir)) {
1305         if (! mkdir($currdir, 0750)) {
1306             notify("ERROR: You need to create the directory $currdir with web server write access");
1307             return false;
1308         }
1309     }
1310
1311     $dirarray = explode("/", $directory);
1312
1313     foreach ($dirarray as $dir) {
1314         $currdir = "$currdir/$dir";
1315         if (! file_exists($currdir)) {
1316             if (! mkdir($currdir, 0750)) {
1317                 notify("ERROR: Could not find or create a directory ($currdir)");
1318                 return false;
1319             }
1320         }
1321     }
1322
1323     return $currdir;
1324 }
1325
1326
1327 function get_directory_list( $rootdir ) {
1328 // Returns an array with all the filenames in
1329 // all subdirectories, relative to the given rootdir.
1330
1331     $dirs = array();
1332
1333     $dir = opendir( $rootdir );
1334
1335     while( $file = readdir( $dir ) ) {
1336         $fullfile = $rootdir."/".$file;
1337         if ($file != "." and $file != "..") {
1338             if (filetype($fullfile) == "dir") {
1339                 $subdirs = get_directory_list($fullfile);
1340                 foreach ($subdirs as $subdir) {
1341                     $dirs[] = $file."/".$subdir;
1342                 }
1343             } else {
1344                 $dirs[] = $file;
1345             }
1346         }
1347     }
1348
1349     return $dirs;
1350 }
1351
1352 function get_real_size($size=0) {
1353 // Converts numbers like 10M into bytes
1354     if (!$size) {
1355         return 0;
1356     }
1357     $scan['MB'] = 1048576;
1358     $scan['M'] = 1048576;
1359     $scan['KB'] = 1024;
1360     $scan['K'] = 1024;
1361
1362     while (list($key) = each($scan)) {
1363         if ((strlen($size)>strlen($key))&&(substr($size, strlen($size) - strlen($key))==$key)) {
1364             $size = substr($size, 0, strlen($size) - strlen($key)) * $scan[$key];
1365             break;
1366         }
1367     }
1368     return $size;
1369 }
1370
1371 function clean_filename($string) {
1372     $string = eregi_replace("\.\.", "", $string);
1373     $string = eregi_replace("[^([:alnum:]|\.)]", "_", $string);
1374     return    eregi_replace("_+", "_", $string);
1375 }
1376
1377
1378 /// STRING TRANSLATION  ////////////////////////////////////////
1379
1380 function print_string($identifier, $module="", $a=NULL) {
1381     echo get_string($identifier, $module, $a);
1382 }
1383
1384
1385 function get_string($identifier, $module="", $a=NULL) {
1386 // Return the translated string specified by $identifier as
1387 // for $module.  Uses the same format files as STphp.
1388 // $a is an object, string or number that can be used
1389 // within translation strings
1390 //
1391 // eg "hello \$a->firstname \$a->lastname"
1392 // or "hello \$a"
1393
1394     global $CFG, $USER;
1395
1396     if (isset($USER->lang)) {    // User language can override site language
1397         $lang = $USER->lang;
1398     } else {
1399         $lang = $CFG->lang;
1400     }
1401
1402     if ($module == "") {
1403         $module = "moodle";
1404     }
1405
1406     $langpath = "$CFG->dirroot/lang";
1407     $langfile = "$langpath/$lang/$module.php";
1408
1409     if (!file_exists($langfile)) {                // try English instead
1410         $langfile = "$langpath/en/$module.php";
1411         if (!file_exists($langfile)) {
1412             return "ERROR: No lang file ($langpath/en/$module.php)!";
1413         }
1414     }
1415
1416     if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
1417
1418         eval($result);
1419         return $resultstring;
1420
1421     } else {
1422         if ($lang == "en") {
1423             return "ERROR: '$identifier' is missing!";
1424
1425         } else {   // Try looking in the english file.
1426             $langfile = "$langpath/en/$module.php";
1427             if (!file_exists($langfile)) {
1428                 return "ERROR: No lang file ($langpath/en/$module.php)!";
1429             }
1430             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
1431                 eval($result);
1432                 return $resultstring;
1433             } else {
1434                 return "ERROR: '$identifier' is missing!";
1435             }
1436         }
1437     }
1438 }
1439
1440
1441 function get_string_from_file($identifier, $langfile, $destination) {
1442 // This function is only used from get_string().
1443     include ($langfile);
1444
1445     if (!isset ($string[$identifier])) {
1446         return false;
1447     }
1448
1449     return "$destination = sprintf(\"".$string[$identifier]."\");";
1450 }
1451
1452
1453 /// ENCRYPTION  ////////////////////////////////////////////////
1454
1455 function rc4encrypt($data) {
1456     $password = "nfgjeingjk";
1457     return endecrypt($password, $data, "");
1458 }
1459
1460 function rc4decrypt($data) {
1461     $password = "nfgjeingjk";
1462     return endecrypt($password, $data, "de");
1463 }
1464
1465 function endecrypt ($pwd, $data, $case) {
1466 // Based on a class by Mukul Sabharwal [mukulsabharwal@yahoo.com]
1467
1468     if ($case == 'de') {
1469         $data = urldecode($data);
1470     }
1471
1472     $key[] = "";
1473     $box[] = "";
1474     $temp_swap = "";
1475     $pwd_length = 0;
1476
1477     $pwd_length = strlen($pwd);
1478
1479     for ($i = 0; $i <= 255; $i++) {
1480         $key[$i] = ord(substr($pwd, ($i % $pwd_length), 1));
1481         $box[$i] = $i;
1482     }
1483
1484     $x = 0;
1485
1486     for ($i = 0; $i <= 255; $i++) {
1487         $x = ($x + $box[$i] + $key[$i]) % 256;
1488         $temp_swap = $box[$i];
1489         $box[$i] = $box[$x];
1490         $box[$x] = $temp_swap;
1491     }
1492
1493     $temp = "";
1494     $k = "";
1495
1496     $cipherby = "";
1497     $cipher = "";
1498
1499     $a = 0;
1500     $j = 0;
1501
1502     for ($i = 0; $i < strlen($data); $i++) {
1503         $a = ($a + 1) % 256;
1504         $j = ($j + $box[$a]) % 256;
1505         $temp = $box[$a];
1506         $box[$a] = $box[$j];
1507         $box[$j] = $temp;
1508         $k = $box[(($box[$a] + $box[$j]) % 256)];
1509         $cipherby = ord(substr($data, $i, 1)) ^ $k;
1510         $cipher .= chr($cipherby);
1511     }
1512
1513     if ($case == 'de') {
1514         $cipher = urldecode(urlencode($cipher));
1515     } else {
1516         $cipher = urlencode($cipher);
1517     }
1518
1519     return $cipher;
1520 }
1521
1522
1523 /// MISCELLANEOUS ////////////////////////////////////////////////////////////////////
1524
1525 function count_words($string) {
1526     $string = strip_tags($string);
1527     return count(preg_split("/\w\b/", $string)) - 1;
1528 }
1529
1530 function getweek ($startdate, $thedate) {
1531 // Given dates in seconds, how many weeks is the date from startdate
1532 // The first week is 1, the second 2 etc ...
1533
1534     if ($thedate < $startdate) {   // error
1535         return 0;
1536     }
1537
1538     return floor(($thedate - $startdate) / 604800.0) + 1;
1539 }
1540
1541 function add_to_log($course, $module, $action, $url="", $info="") {
1542 // Add an entry to the log table.  These are "action" focussed rather
1543 // than web server hits, and provide a way to easily reconstruct what
1544 // any particular student has been doing.
1545 //
1546 // course = the course id
1547 // module = forum, journal, reading, course, user etc
1548 // action = view, edit, post (often but not always the same as the file.php)
1549 // url    = the file and parameters used to see the results of the action
1550 // info   = additional description information
1551
1552
1553     global $db, $USER, $REMOTE_ADDR;
1554
1555     if (isset($USER->realuser)) {  // Don't log
1556         return;
1557     }
1558
1559     $timenow = time();
1560     $info = addslashes($info);
1561
1562     $result = $db->Execute("INSERT INTO log
1563                             SET time = '$timenow',
1564                                 user = '$USER->id',
1565                                 course = '$course',
1566                                 ip = '$REMOTE_ADDR',
1567                                 module = '$module',
1568                                 action = '$action',
1569                                 url = '$url',
1570                                 info = '$info'");
1571     if (!$result) {
1572         echo "<P>Error: Could not insert a new entry to the Moodle log</P>";  // Don't throw an error
1573     }
1574 }
1575
1576 function generate_password($maxlen=10) {
1577 // returns a randomly generated password of length $maxlen.  inspired by
1578 // http://www.phpbuilder.com/columns/jesus19990502.php3
1579
1580     global $CFG;
1581
1582     $fillers = "1234567890!$-+";
1583     $wordlist = file($CFG->wordlist);
1584
1585     srand((double) microtime() * 1000000);
1586     $word1 = trim($wordlist[rand(0, count($wordlist) - 1)]);
1587     $word2 = trim($wordlist[rand(0, count($wordlist) - 1)]);
1588     $filler1 = $fillers[rand(0, strlen($fillers) - 1)];
1589
1590     return substr($word1 . $filler1 . $word2, 0, $maxlen);
1591 }
1592
1593 function moodle_needs_upgrading() {
1594 // Checks version numbers of Main code and all modules to see
1595 // if there are any mismatches ... returns true or false
1596     global $CFG;
1597
1598     include_once("$CFG->dirroot/version.php");  # defines $version and upgrades
1599     if ($dversion = get_field("config", "value", "name", "version")) {
1600         if ($version > $dversion) {
1601             return true;
1602         }
1603         if ($mods = get_list_of_plugins("mod")) {
1604             foreach ($mods as $mod) {
1605                 $fullmod = "$CFG->dirroot/mod/$mod";
1606                 unset($module);
1607                 include_once("$fullmod/version.php");  # defines $module with version etc
1608                 if ($currmodule = get_record("modules", "name", $mod)) {
1609                     if ($module->version > $currmodule->version) {
1610                         return true;
1611                     }
1612                 }
1613             }
1614         }
1615     } else {
1616         return true;
1617     }
1618     return false;
1619 }
1620
1621
1622 function get_list_of_plugins($plugin="mod") {
1623 // Lists plugin directories within some directory
1624
1625     global $CFG;
1626
1627     $basedir = opendir("$CFG->dirroot/$plugin");
1628     while ($dir = readdir($basedir)) {
1629         if ($dir == "." || $dir == ".." || $dir == "CVS") {
1630             continue;
1631         }
1632         if (filetype("$CFG->dirroot/$plugin/$dir") != "dir") {
1633             continue;
1634         }
1635         $plugins[] = $dir;
1636     }
1637     if ($plugins) {
1638         asort($plugins);
1639     }
1640     return $plugins;
1641 }
1642
1643
1644 function iswindows() {
1645 // True if this is Windows, False if not.
1646
1647    global $WINDIR;
1648
1649    return isset($WINDIR);
1650 }
1651
1652 function check_php_version($version="4.1.0") {
1653 // Returns true is the current version of PHP is greater that the specified one
1654     $minversion = intval(str_replace(".", "", $version));
1655     $curversion = intval(str_replace(".", "", phpversion()));
1656     return ($curversion >= $minversion);
1657 }
1658
1659
1660
1661 ?>