lib/util.php

   1 <?php
   2 /*
   3  * Laconica - a distributed open-source microblogging tool
   4  * Copyright (C) 2008, Controlez-Vous, Inc.
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Affero General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Affero General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Affero General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* XXX: break up into separate modules (HTTP, HTML, user, files) */
  21
  22 # Show a server error
  23
  24 function common_server_error($msg, $code=500) {
  25         static $status = array(500 => 'Internal Server Error',
  26                                                    501 => 'Not Implemented',
  27                                                    502 => 'Bad Gateway',
  28                                                    503 => 'Service Unavailable',
  29                                                    504 => 'Gateway Timeout',
  30                                                    505 => 'HTTP Version Not Supported');
  31
  32         if (!array_key_exists($code, $status)) {
  33                 $code = 500;
  34         }
  35
  36         $status_string = $status[$code];
  37
  38         header('HTTP/1.1 '.$code.' '.$status_string);
  39         header('Content-type: text/plain');
  40
  41         print $msg;
  42         print "\n";
  43         exit();
  44 }
  45
  46 # Show a user error
  47 function common_user_error($msg, $code=400) {
  48         static $status = array(400 => 'Bad Request',
  49                                                    401 => 'Unauthorized',
  50                                                    402 => 'Payment Required',
  51                                                    403 => 'Forbidden',
  52                                                    404 => 'Not Found',
  53                                                    405 => 'Method Not Allowed',
  54                                                    406 => 'Not Acceptable',
  55                                                    407 => 'Proxy Authentication Required',
  56                                                    408 => 'Request Timeout',
  57                                                    409 => 'Conflict',
  58                                                    410 => 'Gone',
  59                                                    411 => 'Length Required',
  60                                                    412 => 'Precondition Failed',
  61                                                    413 => 'Request Entity Too Large',
  62                                                    414 => 'Request-URI Too Long',
  63                                                    415 => 'Unsupported Media Type',
  64                                                    416 => 'Requested Range Not Satisfiable',
  65                                                    417 => 'Expectation Failed');
  66
  67         if (!array_key_exists($code, $status)) {
  68                 $code = 400;
  69         }
  70
  71         $status_string = $status[$code];
  72
  73         header('HTTP/1.1 '.$code.' '.$status_string);
  74
  75         common_show_header('Error');
  76         common_element('div', array('class' => 'error'), $msg);
  77         common_show_footer();
  78 }
  79
  80 $xw = null;
  81
  82 # Start an HTML element
  83 function common_element_start($tag, $attrs=NULL) {
  84         global $xw;
  85         $xw->startElement($tag);
  86         if (is_array($attrs)) {
  87                 foreach ($attrs as $name => $value) {
  88                         $xw->writeAttribute($name, $value);
  89                 }
  90         } else if (is_string($attrs)) {
  91                 $xw->writeAttribute('class', $attrs);
  92         }
  93 }
  94
  95 function common_element_end($tag) {
  96         global $xw;
  97         $xw->endElement();
  98 }
  99
 100 function common_element($tag, $attrs=NULL, $content=NULL) {
 101     common_element_start($tag, $attrs);
 102         if ($content) {
 103                 global $xw;
 104                 $xw->text($content);
 105         }
 106         common_element_end($tag);
 107 }
 108
 109 function common_start_xml($doc=NULL, $public=NULL, $system=NULL) {
 110         global $xw;
 111         $xw = new XMLWriter();
 112         $xw->openURI('php://output');
 113         $xw->setIndent(true);
 114         $xw->startDocument('1.0', 'UTF-8');
 115         if ($doc) {
 116                 $xw->writeDTD($doc, $public, $system);
 117         }
 118 }
 119
 120 function common_end_xml() {
 121         global $xw;
 122         $xw->endDocument();
 123         $xw->flush();
 124 }
 125
 126 define('PAGE_TYPE_PREFS', 'application/xhtml+xml,text/html;q=0.7,application/xml;q=0.3,text/xml;q=0.2');
 127
 128 function common_show_header($pagetitle, $callable=NULL, $data=NULL, $headercall=NULL) {
 129         global $config, $xw;
 130
 131         $httpaccept = isset($_SERVER['HTTP_ACCEPT']) ? $_SERVER['HTTP_ACCEPT'] : NULL;
 132
 133         # XXX: allow content negotiation for RDF, RSS, or XRDS
 134
 135         $type = common_negotiate_type(common_accept_to_prefs($httpaccept),
 136                                                                   common_accept_to_prefs(PAGE_TYPE_PREFS));
 137
 138         if (!$type) {
 139                 common_client_error(_t('This page is not available in a media type you accept'), 406);
 140                 exit(0);
 141         }
 142
 143         header('Content-Type: '.$type);
 144
 145         common_start_xml('html',
 146                                          '-//W3C//DTD XHTML 1.0 Strict//EN',
 147                                          'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd');
 148
 149         # FIXME: correct language for interface
 150
 151         common_element_start('html', array('xmlns' => 'http://www.w3.org/1999/xhtml',
 152                                                                            'xml:lang' => 'en',
 153                                                                            'lang' => 'en'));
 154
 155         common_element_start('head');
 156         common_element('title', NULL,
 157                                    $pagetitle . " - " . $config['site']['name']);
 158         common_element('link', array('rel' => 'stylesheet',
 159                                                                  'type' => 'text/css',
 160                                                                  'href' => theme_path('display.css'),
 161                                                                  'media' => 'screen, projection, tv'));
 162         foreach (array(6,7) as $ver) {
 163                 if (file_exists(theme_file('ie'.$ver.'.css'))) {
 164                         # Yes, IE people should be put in jail.
 165                         $xw->writeComment('[if lte IE '.$ver.']><link rel="stylesheet" type="text/css" '.
 166                                                           'href="'.theme_path('ie'.$ver.'.css').' /><![endif]');
 167                 }
 168         }
 169
 170         common_element('script', array('type' => 'text/javascript',
 171                                                                    'src' => common_path('js/jquery.min.js')),
 172                                    ' ');
 173
 174         if ($callable) {
 175                 if ($data) {
 176                         call_user_func($callable, $data);
 177                 } else {
 178                         call_user_func($callable);
 179                 }
 180         }
 181         common_element_end('head');
 182         common_element_start('body');
 183         common_element_start('div', array('id' => 'wrap'));
 184         common_element_start('div', array('id' => 'header'));
 185         common_nav_menu();
 186         if ($config['site']['logo'] || file_exists(theme_file('logo.png'))) {
 187                 common_element_start('a', array('href' => common_local_url('public')));
 188                 common_element('img', array('src' => ($config['site']['logo']) ?
 189                                                                         ($config['site']['logo']) : theme_path('logo.png'),
 190                                                                         'alt' => $config['site']['name'],
 191                                                                         'id' => 'logo'));
 192                 common_element_end('a');
 193         }
 194         common_element('h1', 'pagetitle', $pagetitle);
 195         common_element('h2', 'sitename', $config['site']['name']);
 196
 197         if ($headercall) {
 198                 if ($data) {
 199                         call_user_func($headercall, $data);
 200                 } else {
 201                         call_user_func($headercall);
 202                 }
 203         }
 204         common_element_end('div');
 205         common_element_start('div', array('id' => 'content'));
 206 }
 207
 208 function common_show_footer() {
 209         global $xw, $config;
 210         common_element_end('div'); # content div
 211         common_foot_menu();
 212         common_element_start('div', array('id' => 'footer'));
 213         common_element_start('p', 'laconica');
 214         common_text(_t('This site is running the '));
 215         common_element('a', array('class' => 'software',
 216                                                           href => 'http://laconi.ca/'),
 217                                    'Laconica');
 218         common_text(_t('microblogging tool, version ' . LACONICA_VERSION . ', available under the '));
 219         common_element('a', array(href => 'http://www.fsf.org/licensing/licenses/agpl-3.0.html'),
 220                                    'GNU Affero General Public License');
 221         common_text(_t('.'));
 222         common_element_end('p');
 223         common_element('img', array('id' => 'cc',
 224                                                                 'src' => $config['license']['image'],
 225                                                                 'alt' => $config['license']['title']));
 226         common_element_start('p');
 227         common_text(_t('Unless otherwise specified, contents of this site are copyright by the contributors and available under the '));
 228         common_element('a', array('class' => 'license',
 229                                                           'rel' => 'license',
 230                                                           href => $config['license']['url']),
 231                                    $config['license']['title']);
 232         common_text(_t('. Contributors should be attributed by full name or nickname.'));
 233         common_element_end('p');
 234         common_element_end('div');
 235         common_element_end('div');
 236         common_element_end('body');
 237         common_element_end('html');
 238         common_end_xml();
 239 }
 240
 241 function common_text($txt) {
 242         global $xw;
 243         $xw->text($txt);
 244 }
 245
 246 function common_raw($xml) {
 247         global $xw;
 248         $xw->writeRaw($xml);
 249 }
 250
 251 function common_nav_menu() {
 252         $user = common_current_user();
 253         common_element_start('ul', array('id' => 'nav'));
 254         if ($user) {
 255                 common_menu_item(common_local_url('all', array('nickname' => $user->nickname)),
 256                                                  _t('Home'));
 257         }
 258         common_menu_item(common_local_url('public'), _t('Public'));
 259         common_menu_item(common_local_url('doc', array('title' => 'help')),
 260                                          _t('Help'));
 261         if ($user) {
 262                 common_menu_item(common_local_url('profilesettings'),
 263                                                  _t('Settings'));
 264                 common_menu_item(common_local_url('logout'),
 265                                                  _t('Logout'));
 266         } else {
 267                 common_menu_item(common_local_url('login'), _t('Login'));
 268                 common_menu_item(common_local_url('register'), _t('Register'));
 269         }
 270         common_element_end('ul');
 271 }
 272
 273 function common_foot_menu() {
 274         common_element_start('ul', array('id' => 'nav_sub'));
 275         common_menu_item(common_local_url('doc', array('title' => 'about')),
 276                                          _t('About'));
 277         common_menu_item(common_local_url('doc', array('title' => 'privacy')),
 278                                          _t('Privacy'));
 279         common_menu_item(common_local_url('doc', array('title' => 'source')),
 280                                          _t('Source'));
 281         common_element_end('ul');
 282 }
 283
 284 function common_menu_item($url, $text, $title=NULL, $is_selected=false) {
 285         $lattrs = array();
 286         if ($is_selected) {
 287                 $lattrs['class'] = 'current';
 288         }
 289         common_element_start('li', $lattrs);
 290         $attrs['href'] = $url;
 291         if ($title) {
 292                 $attrs['title'] = $title;
 293         }
 294         common_element('a', $attrs, $text);
 295         common_element_end('li');
 296 }
 297
 298 function common_input($id, $label, $value=NULL,$instructions=NULL) {
 299         common_element_start('p');
 300         common_element('label', array('for' => $id), $label);
 301         $attrs = array('name' => $id,
 302                                    'type' => 'text',
 303                                    'id' => $id);
 304         if ($value) {
 305                 $attrs['value'] = htmlspecialchars($value);
 306         }
 307         common_element('input', $attrs);
 308         if ($instructions) {
 309                 common_element('span', 'input_instructions', $instructions);
 310         }
 311         common_element_end('p');
 312 }
 313
 314 function common_hidden($id, $value) {
 315         common_element('input', array('name' => $id,
 316                                                                   'type' => 'hidden',
 317                                                                   'id' => $id,
 318                                                                   'value' => $value));
 319 }
 320
 321 function common_password($id, $label, $instructions=NULL) {
 322         common_element_start('p');
 323         common_element('label', array('for' => $id), $label);
 324         $attrs = array('name' => $id,
 325                                    'type' => 'password',
 326                                    'id' => $id);
 327         common_element('input', $attrs);
 328         if ($instructions) {
 329                 common_element('span', 'input_instructions', $instructions);
 330         }
 331         common_element_end('p');
 332 }
 333
 334 function common_submit($id, $label) {
 335         global $xw;
 336         common_element_start('p');
 337         common_element('input', array('type' => 'submit',
 338                                                                   'id' => $id,
 339                                                                   'name' => $id,
 340                                                                   'value' => $label));
 341         common_element_end('p');
 342 }
 343
 344 function common_textarea($id, $label, $content=NULL, $instructions=NULL) {
 345         common_element_start('p');
 346         common_element('label', array('for' => $id), $label);
 347         common_element('textarea', array('rows' => 3,
 348                                                                          'cols' => 40,
 349                                                                          'name' => $id,
 350                                                                          'id' => $id),
 351                                    ($content) ? $content : ' ');
 352         if ($instructions) {
 353                 common_element('span', 'input_instructions', $instructions);
 354         }
 355         common_element_end('p');
 356 }
 357
 358 # salted, hashed passwords are stored in the DB
 359
 360 function common_munge_password($id, $password) {
 361         return md5($id . $password);
 362 }
 363
 364 # check if a username exists and has matching password
 365 function common_check_user($nickname, $password) {
 366         $user = User::staticGet('nickname', $nickname);
 367         if (is_null($user)) {
 368                 return false;
 369         } else {
 370                 return (0 == strcmp(common_munge_password($password, $user->id),
 371                                                         $user->password));
 372         }
 373 }
 374
 375 # is the current user logged in?
 376 function common_logged_in() {
 377         return (!is_null(common_current_user()));
 378 }
 379
 380 function common_have_session() {
 381         return (0 != strcmp(session_id(), ''));
 382 }
 383
 384 function common_ensure_session() {
 385         if (!common_have_session()) {
 386                 @session_start();
 387         }
 388 }
 389
 390 function common_set_user($nickname) {
 391         if (is_null($nickname) && common_have_session()) {
 392                 unset($_SESSION['userid']);
 393                 return true;
 394         } else {
 395                 $user = User::staticGet('nickname', $nickname);
 396                 if ($user) {
 397                         common_ensure_session();
 398                         $_SESSION['userid'] = $user->id;
 399                         return true;
 400                 } else {
 401                         return false;
 402                 }
 403         }
 404         return false;
 405 }
 406
 407 # who is the current user?
 408 function common_current_user() {
 409         static $user = NULL; # FIXME: global memcached
 410         if (is_null($user)) {
 411                 common_ensure_session();
 412                 $id = $_SESSION['userid'];
 413                 if ($id) {
 414                         $user = User::staticGet($id);
 415                 }
 416         }
 417         return $user;
 418 }
 419
 420 # get canonical version of nickname for comparison
 421 function common_canonical_nickname($nickname) {
 422         # XXX: UTF-8 canonicalization (like combining chars)
 423         return strtolower($nickname);
 424 }
 425
 426 # get canonical version of email for comparison
 427 function common_canonical_email($email) {
 428         # XXX: canonicalize UTF-8
 429         # XXX: lcase the domain part
 430         return $email;
 431 }
 432
 433 define('URL_REGEX', '^|[ \t\r\n])((ftp|http|https|gopher|mailto|news|nntp|telnet|wais|file|prospero|aim|webcal):(([A-Za-z0-9$_.+!*(),;/?:@&~=-])|%[A-Fa-f0-9]{2}){2,}(#([a-zA-Z0-9][a-zA-Z0-9$_.+!*(),;/?:@&~=%-]*))?([A-Za-z0-9$_+!*();/?:~-]))');
 434
 435 function common_render_content($text, $notice) {
 436         $r = htmlspecialchars($text);
 437         $id = $notice->profile_id;
 438         $r = preg_replace('@https?://\S+@', '<a href="\0" class="extlink">\0</a>', $r);
 439         $r = preg_replace('/(^|\b)@([\w-]+)($|\b)/e', "'\\1@'.common_at_link($id, '\\2').'\\3'", $r);
 440         # XXX: # tags
 441         # XXX: machine tags
 442         return $r;
 443 }
 444
 445 function common_at_link($sender_id, $nickname) {
 446         # Try to find profiles this profile is subscribed to that have this nickname
 447         $recipient = new Profile();
 448         # XXX: chokety and bad
 449         $recipient->whereAdd('EXISTS (SELECT subscribed from subscription where subscriber = '.$sender_id.' and subscribed = id)', 'AND');
 450         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 451         if ($recipient->find(TRUE)) {
 452                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistenee">'.$nickname.'</a>';
 453         }
 454         # Try to find profiles that listen to this profile and that have this nickname
 455         $recipient = new Profile();
 456         # XXX: chokety and bad
 457         $recipient->whereAdd('EXISTS (SELECT subscriber from subscription where subscribed = '.$sender_id.' and subscriber = id)', 'AND');
 458         $recipient->whereAdd('nickname = "' . trim($nickname) . '"', 'AND');
 459         if ($recipient->find(TRUE)) {
 460                 return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink tolistener">'.$nickname.'</a>';
 461         }
 462         # If this is a local user, try to find a local user with that nickname.
 463         $sender = User::staticGet($sender_id);
 464         if ($sender) {
 465                 $recipient_user = User::staticGet('nickname', $nickname);
 466                 if ($recipient_user) {
 467                         $recipient = $recipient->getProfile();
 468                         return '<a href="'.htmlspecialchars($recipient->profileurl).'" class="atlink usertouser">'.$nickname.'</a>';
 469                 }
 470         }
 471         # Otherwise, no links. @messages from local users to remote users,
 472         # or from remote users to other remote users, are just
 473         # outside our ability to make intelligent guesses about
 474         return $nickname;
 475 }
 476
 477 // where should the avatar go for this user?
 478
 479 function common_avatar_filename($id, $extension, $size=NULL, $extra=NULL) {
 480         global $config;
 481
 482         if ($size) {
 483                 return $id . '-' . $size . (($extra) ? ('-' . $extra) : '') . $extension;
 484         } else {
 485                 return $id . '-original' . (($extra) ? ('-' . $extra) : '') . $extension;
 486         }
 487 }
 488
 489 function common_avatar_path($filename) {
 490         global $config;
 491         return INSTALLDIR . '/avatar/' . $filename;
 492 }
 493
 494 function common_avatar_url($filename) {
 495         return common_path('avatar/'.$filename);
 496 }
 497
 498 function common_default_avatar($size) {
 499         static $sizenames = array(AVATAR_PROFILE_SIZE => 'profile',
 500                                                           AVATAR_STREAM_SIZE => 'stream',
 501                                                           AVATAR_MINI_SIZE => 'mini');
 502         return theme_path('default-avatar-'.$sizenames[$size].'.png');
 503 }
 504
 505 function common_local_url($action, $args=NULL) {
 506         global $config;
 507         if ($config['site']['fancy']) {
 508                 return common_fancy_url($action, $args);
 509         } else {
 510                 return common_simple_url($action, $args);
 511         }
 512 }
 513
 514 function common_fancy_url($action, $args=NULL) {
 515         switch (strtolower($action)) {
 516          case 'public':
 517                 if ($args && $args['page']) {
 518                         return common_path('?page=' . $args['page']);
 519                 } else {
 520                         return common_path('');
 521                 }
 522          case 'publicrss':
 523                 return common_path('rss');
 524          case 'doc':
 525                 return common_path('doc/'.$args['title']);
 526          case 'login':
 527          case 'logout':
 528          case 'register':
 529          case 'subscribe':
 530          case 'unsubscribe':
 531                 return common_path('main/'.$action);
 532          case 'avatar':
 533          case 'password':
 534                 return common_path('settings/'.$action);
 535          case 'profilesettings':
 536                 return common_path('settings/profile');
 537          case 'newnotice':
 538                 return common_path('notice/new');
 539          case 'shownotice':
 540                 return common_path('notice/'.$args['notice']);
 541          case 'xrds':
 542          case 'foaf':
 543                 return common_path($args['nickname'].'/'.$action);
 544          case 'subscriptions':
 545          case 'subscribed':
 546          case 'all':
 547                 if ($args && $args['page']) {
 548                         return common_path($args['nickname'].'/'.$action.'?page=' . $args['page']);
 549                 } else {
 550                         return common_path($args['nickname'].'/'.$action);
 551                 }
 552          case 'allrss':
 553                 return common_path($args['nickname'].'/all/rss');
 554          case 'userrss':
 555                 return common_path($args['nickname'].'/rss');
 556          case 'showstream':
 557                 if ($args && $args['page']) {
 558                         return common_path($args['nickname'].'?page=' . $args['page']);
 559                 } else {
 560                         return common_path($args['nickname']);
 561                 }
 562          default:
 563                 return common_simple_url($action, $args);
 564         }
 565 }
 566
 567 function common_simple_url($action, $args=NULL) {
 568         global $config;
 569         /* XXX: pretty URLs */
 570         $extra = '';
 571         if ($args) {
 572                 foreach ($args as $key => $value) {
 573                         $extra .= "&${key}=${value}";
 574                 }
 575         }
 576         return common_path("index.php?action=${action}${extra}");
 577 }
 578
 579 function common_path($relative) {
 580         global $config;
 581         $pathpart = ($config['site']['path']) ? $config['site']['path']."/" : '';
 582         return "http://".$config['site']['server'].'/'.$pathpart.$relative;
 583 }
 584
 585 function common_date_string($dt) {
 586         // XXX: do some sexy date formatting
 587         // return date(DATE_RFC822, $dt);
 588         return $dt;
 589 }
 590
 591 function common_date_w3dtf($dt) {
 592         $t = strtotime($dt);
 593         return date(DATE_W3C, $t);
 594 }
 595
 596 function common_redirect($url, $code=307) {
 597         static $status = array(301 => "Moved Permanently",
 598                                                    302 => "Found",
 599                                                    303 => "See Other",
 600                                                    307 => "Temporary Redirect");
 601         header("Status: ${code} $status[$code]");
 602         header("Location: $url");
 603         common_element('a', array('href' => $url), $url);
 604 }
 605
 606 function common_broadcast_notice($notice, $remote=false) {
 607         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 608         if (!$remote) {
 609                 # Make sure we have the OMB stuff
 610                 require_once(INSTALLDIR.'/lib/omb.php');
 611                 omb_broadcast_remote_subscribers($notice);
 612         }
 613         // XXX: broadcast notices to Jabber
 614         // XXX: broadcast notices to SMS
 615         // XXX: broadcast notices to other IM
 616         return true;
 617 }
 618
 619 function common_broadcast_profile($profile) {
 620         // XXX: optionally use a queue system like http://code.google.com/p/microapps/wiki/NQDQ
 621         require_once(INSTALLDIR.'/lib/omb.php');
 622         omb_broadcast_profile($profile);
 623         // XXX: Other broadcasts...?
 624         return true;
 625 }
 626
 627 function common_profile_url($nickname) {
 628         return common_local_url('showstream', array('nickname' => $nickname));
 629 }
 630
 631 # Don't call if nobody's logged in
 632
 633 function common_notice_form() {
 634         $user = common_current_user();
 635         assert(!is_null($user));
 636         common_element_start('form', array('id' => 'status_form',
 637                                                                            'method' => 'POST',
 638                                                                            'action' => common_local_url('newnotice')));
 639         common_element_start('p');
 640         common_element('label', array('for' => 'status_update',
 641                                                                   'id' => 'status_label'),
 642                                    _t('What\'s up, ').$user->nickname.'?');
 643         common_element('textarea', array('id' => 'status_textarea',
 644                                                                          'name' => 'status_textarea'));
 645         common_element('input', array('id' => 'status_submit',
 646                                                                   'name' => 'status_submit',
 647                                                                   'type' => 'submit',
 648                                                                   'value' => _t('Send')));
 649         common_element_end('p');
 650         common_element_end('form');
 651 }
 652
 653 function common_mint_tag($extra) {
 654         global $config;
 655         return
 656           'tag:'.$config['tag']['authority'].','.
 657           $config['tag']['date'].':'.$config['tag']['prefix'].$extra;
 658 }
 659
 660 # Should make up a reasonable root URL
 661
 662 function common_root_url() {
 663         return common_path('');
 664 }
 665
 666 # returns $bytes bytes of random data as a hexadecimal string
 667 # "good" here is a goal and not a guarantee
 668
 669 function common_good_rand($bytes) {
 670         # XXX: use random.org...?
 671         if (file_exists('/dev/urandom')) {
 672                 return common_urandom($bytes);
 673         } else { # FIXME: this is probably not good enough
 674                 return common_mtrand($bytes);
 675         }
 676 }
 677
 678 function common_urandom($bytes) {
 679         $h = fopen('/dev/urandom', 'rb');
 680         # should not block
 681         $src = fread($h, $bytes);
 682         fclose($h);
 683         $enc = '';
 684         for ($i = 0; $i < $bytes; $i++) {
 685                 $enc .= sprintf("%02x", (ord($src[$i])));
 686         }
 687         return $enc;
 688 }
 689
 690 function common_mtrand($bytes) {
 691         $enc = '';
 692         for ($i = 0; $i < $bytes; $i++) {
 693                 $enc .= sprintf("%02x", mt_rand(0, 255));
 694         }
 695         return $enc;
 696 }
 697
 698 function common_set_returnto($url) {
 699         common_ensure_session();
 700         $_SESSION['returnto'] = $url;
 701 }
 702
 703 function common_get_returnto() {
 704         common_ensure_session();
 705         return $_SESSION['returnto'];
 706 }
 707
 708 function common_timestamp() {
 709         return date('YmdHis');
 710 }
 711
 712 // XXX: set up gettext
 713
 714 function _t($str) {
 715         return $str;
 716 }
 717
 718 function common_ensure_syslog() {
 719         static $initialized = false;
 720         if (!$initialized) {
 721                 global $config;
 722                 define_syslog_variables();
 723                 openlog($config['syslog']['appname'], 0, LOG_USER);
 724                 $initialized = true;
 725         }
 726 }
 727
 728 function common_log($priority, $msg, $filename=NULL) {
 729         common_ensure_syslog();
 730         syslog($priority, $msg);
 731 }
 732
 733 function common_debug($msg, $filename=NULL) {
 734         if ($filename) {
 735                 common_log(LOG_DEBUG, basename($filename).' - '.$msg);
 736         } else {
 737                 common_log(LOG_DEBUG, $msg);
 738         }
 739 }
 740
 741 function common_valid_http_url($url) {
 742         return Validate::uri($url, array('allowed_schemes' => array('http', 'https')));
 743 }
 744
 745 function common_valid_tag($tag) {
 746         if (preg_match('/^tag:(.*?),(\d{4}(-\d{2}(-\d{2})?)?):(.*)$/', $tag, $matches)) {
 747                 return (Validate::email($matches[1]) ||
 748                                 preg_match('/^([\w-\.]+)$/', $matches[1]));
 749         }
 750         return false;
 751 }
 752
 753 # Does a little before-after block for next/prev page
 754
 755 function common_pagination($have_before, $have_after, $page, $action, $args=NULL) {
 756
 757         if ($have_before || $have_after) {
 758                 common_element_start('div', array('id' => 'pagination'));
 759                 common_element_start('ul', array('id' => 'nav_pagination'));
 760         }
 761
 762         if ($have_before) {
 763                 $pargs = array('page' => $page-1);
 764                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 765
 766                 common_element_start('li', 'before');
 767                 common_element('a', array('href' => common_local_url($action, $newargs)),
 768                                            _t('« After'));
 769                 common_element_end('li');
 770         }
 771
 772         if ($have_after) {
 773                 $pargs = array('page' => $page+1);
 774                 $newargs = ($args) ? array_merge($args,$pargs) : $pargs;
 775                 common_element_start('li', 'after');
 776                 common_element('a', array('href' => common_local_url($action, $newargs)),
 777                                                    _t('Before »'));
 778                 common_element_end('li');
 779         }
 780
 781         if ($have_before || $have_after) {
 782                 common_element_end('ul');
 783                 common_element_end('div');
 784         }
 785 }
 786
 787 /* Following functions are copied from MediaWiki GlobalFunctions.php
 788  * and written by Evan Prodromou. */
 789
 790 function common_accept_to_prefs($accept, $def = '*/*') {
 791         # No arg means accept anything (per HTTP spec)
 792         if(!$accept) {
 793                 return array($def => 1);
 794         }
 795
 796         $prefs = array();
 797
 798         $parts = explode(',', $accept);
 799
 800         foreach($parts as $part) {
 801                 # FIXME: doesn't deal with params like 'text/html; level=1'
 802                 @list($value, $qpart) = explode(';', $part);
 803                 $match = array();
 804                 if(!isset($qpart)) {
 805                         $prefs[$value] = 1;
 806                 } elseif(preg_match('/q\s*=\s*(\d*\.\d+)/', $qpart, $match)) {
 807                         $prefs[$value] = $match[1];
 808                 }
 809         }
 810
 811         return $prefs;
 812 }
 813
 814 function common_mime_type_match($type, $avail) {
 815         if(array_key_exists($type, $avail)) {
 816                 return $type;
 817         } else {
 818                 $parts = explode('/', $type);
 819                 if(array_key_exists($parts[0] . '/*', $avail)) {
 820                         return $parts[0] . '/*';
 821                 } elseif(array_key_exists('*/*', $avail)) {
 822                         return '*/*';
 823                 } else {
 824                         return NULL;
 825                 }
 826         }
 827 }
 828
 829 function common_negotiate_type($cprefs, $sprefs) {
 830         $combine = array();
 831
 832         foreach(array_keys($sprefs) as $type) {
 833                 $parts = explode('/', $type);
 834                 if($parts[1] != '*') {
 835                         $ckey = common_mime_type_match($type, $cprefs);
 836                         if($ckey) {
 837                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
 838                         }
 839                 }
 840         }
 841
 842         foreach(array_keys($cprefs) as $type) {
 843                 $parts = explode('/', $type);
 844                 if($parts[1] != '*' && !array_key_exists($type, $sprefs)) {
 845                         $skey = common_mime_type_match($type, $sprefs);
 846                         if($skey) {
 847                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
 848                         }
 849                 }
 850         }
 851
 852         $bestq = 0;
 853         $besttype = NULL;
 854
 855         foreach(array_keys($combine) as $type) {
 856                 if($combine[$type] > $bestq) {
 857                         $besttype = $type;
 858                         $bestq = $combine[$type];
 859                 }
 860         }
 861
 862         return $besttype;
 863 }
 864
 865 function common_config($main, $sub) {
 866         global $config;
 867         return $config[$main][$sub];
 868 }