includes/installer/Installer.php

   1 <?php
   2 /**
   3  * Base code for MediaWiki installer.
   4  *
   5  * @file
   6  * @ingroup Deployment
   7  */
   8
   9 /**
  10  * This documentation group collects source code files with deployment functionality.
  11  *
  12  * @defgroup Deployment Deployment
  13  */
  14
  15 /**
  16  * Base installer class.
  17  *
  18  * This class provides the base for installation and update functionality
  19  * for both MediaWiki core and extensions.
  20  *
  21  * @ingroup Deployment
  22  * @since 1.17
  23  */
  24 abstract class Installer {
  25
  26         /**
  27          * TODO: make protected?
  28          *
  29          * @var array
  30          */
  31         public $settings;
  32
  33         /**
  34          * Cached DB installer instances, access using getDBInstaller().
  35          *
  36          * @var array
  37          */
  38         protected $dbInstallers = array();
  39
  40         /**
  41          * Minimum memory size in MB.
  42          *
  43          * @var integer
  44          */
  45         protected $minMemorySize = 50;
  46
  47         /**
  48          * Cached Title, used by parse().
  49          *
  50          * @var Title
  51          */
  52         protected $parserTitle;
  53
  54         /**
  55          * Cached ParserOptions, used by parse().
  56          *
  57          * @var ParserOptions
  58          */
  59         protected $parserOptions;
  60
  61         /**
  62          * Known database types. These correspond to the class names <type>Installer,
  63          * and are also MediaWiki database types valid for $wgDBtype.
  64          *
  65          * To add a new type, create a <type>Installer class and a Database<type>
  66          * class, and add a config-type-<type> message to MessagesEn.php.
  67          *
  68          * @var array
  69          */
  70         protected static $dbTypes = array(
  71                 'mysql',
  72                 'postgres',
  73                 'oracle',
  74                 'sqlite',
  75         );
  76
  77         /**
  78          * A list of environment check methods called by doEnvironmentChecks().
  79          * These may output warnings using showMessage(), and/or abort the
  80          * installation process by returning false.
  81          *
  82          * @var array
  83          */
  84         protected $envChecks = array(
  85                 'envLatestVersion',
  86                 'envCheckDB',
  87                 'envCheckRegisterGlobals',
  88                 'envCheckMagicQuotes',
  89                 'envCheckMagicSybase',
  90                 'envCheckMbstring',
  91                 'envCheckZE1',
  92                 'envCheckSafeMode',
  93                 'envCheckXML',
  94                 'envCheckPCRE',
  95                 'envCheckMemory',
  96                 'envCheckCache',
  97                 'envCheckDiff3',
  98                 'envCheckGraphics',
  99                 'envCheckPath',
 100                 'envCheckWriteableDir',
 101                 'envCheckExtension',
 102                 'envCheckShellLocale',
 103                 'envCheckUploadsDirectory',
 104                 'envCheckLibicu'
 105         );
 106
 107         /**
 108          * UI interface for displaying a short message
 109          * The parameters are like parameters to wfMsg().
 110          * The messages will be in wikitext format, which will be converted to an
 111          * output format such as HTML or text before being sent to the user.
 112          */
 113         public abstract function showMessage( $msg /*, ... */ );
 114
 115         /**
 116          * Constructor, always call this from child classes.
 117          */
 118         public function __construct() {
 119                 // Disable the i18n cache and LoadBalancer
 120                 Language::getLocalisationCache()->disableBackend();
 121                 LBFactory::disableBackend();
 122         }
 123
 124         /**
 125          * Get a list of known DB types.
 126          */
 127         public static function getDBTypes() {
 128                 return self::$dbTypes;
 129         }
 130
 131         /**
 132          * Do initial checks of the PHP environment. Set variables according to
 133          * the observed environment.
 134          *
 135          * It's possible that this may be called under the CLI SAPI, not the SAPI
 136          * that the wiki will primarily run under. In that case, the subclass should
 137          * initialise variables such as wgScriptPath, before calling this function.
 138          *
 139          * Under the web subclass, it can already be assumed that PHP 5+ is in use
 140          * and that sessions are working.
 141          *
 142          * @return boolean
 143          */
 144         public function doEnvironmentChecks() {
 145                 $this->showMessage( 'config-env-php', phpversion() );
 146
 147                 $good = true;
 148
 149                 foreach ( $this->envChecks as $check ) {
 150                         $status = $this->$check();
 151                         if ( $status === false ) {
 152                                 $good = false;
 153                         }
 154                 }
 155
 156                 $this->setVar( '_Environment', $good );
 157
 158                 if ( $good ) {
 159                         $this->showMessage( 'config-env-good' );
 160                 } else {
 161                         $this->showMessage( 'config-env-bad' );
 162                 }
 163
 164                 return $good;
 165         }
 166
 167         /**
 168          * Set a MW configuration variable, or internal installer configuration variable.
 169          *
 170          * @param $name String
 171          * @param $value Mixed
 172          */
 173         public function setVar( $name, $value ) {
 174                 $this->settings[$name] = $value;
 175         }
 176
 177         /**
 178          * Get an MW configuration variable, or internal installer configuration variable.
 179          * The defaults come from $GLOBALS (ultimately DefaultSettings.php).
 180          * Installer variables are typically prefixed by an underscore.
 181          *
 182          * @param $name String
 183          * @param $default Mixed
 184          *
 185          * @return mixed
 186          */
 187         public function getVar( $name, $default = null ) {
 188                 if ( !isset( $this->settings[$name] ) ) {
 189                         return $default;
 190                 } else {
 191                         return $this->settings[$name];
 192                 }
 193         }
 194
 195         /**
 196          * Get an instance of DatabaseInstaller for the specified DB type.
 197          *
 198          * @param $type Mixed: DB installer for which is needed, false to use default.
 199          *
 200          * @return DatabaseInstaller
 201          */
 202         public function getDBInstaller( $type = false ) {
 203                 if ( !$type ) {
 204                         $type = $this->getVar( 'wgDBtype' );
 205                 }
 206
 207                 $type = strtolower( $type );
 208
 209                 if ( !isset( $this->dbInstallers[$type] ) ) {
 210                         $class = ucfirst( $type ). 'Installer';
 211                         $this->dbInstallers[$type] = new $class( $this );
 212                 }
 213
 214                 return $this->dbInstallers[$type];
 215         }
 216
 217         /**
 218          * Determine if LocalSettings exists. If it does, return an appropriate
 219          * status for whether we should can upgrade or not.
 220          *
 221          * @return Status
 222          */
 223         public function getLocalSettingsStatus() {
 224                 global $IP;
 225
 226                 $status = Status::newGood();
 227
 228                 wfSuppressWarnings();
 229                 $ls = file_exists( "$IP/LocalSettings.php" );
 230                 wfRestoreWarnings();
 231
 232                 if( $ls ) {
 233                         if( $this->getDBInstaller()->needsUpgrade() ) {
 234                                 $status->warning( 'config-localsettings-upgrade' );
 235                         }
 236                         else {
 237                                 $status->fatal( 'config-localsettings-noupgrade' );
 238                         }
 239                 }
 240
 241                 return $status;
 242         }
 243
 244         /**
 245          * Get a fake password for sending back to the user in HTML.
 246          * This is a security mechanism to avoid compromise of the password in the
 247          * event of session ID compromise.
 248          *
 249          * @param $realPassword String
 250          *
 251          * @return string
 252          */
 253         public function getFakePassword( $realPassword ) {
 254                 return str_repeat( '*', strlen( $realPassword ) );
 255         }
 256
 257         /**
 258          * Set a variable which stores a password, except if the new value is a
 259          * fake password in which case leave it as it is.
 260          *
 261          * @param $name String
 262          * @param $value Mixed
 263          */
 264         public function setPassword( $name, $value ) {
 265                 if ( !preg_match( '/^\*+$/', $value ) ) {
 266                         $this->setVar( $name, $value );
 267                 }
 268         }
 269
 270         /**
 271          * On POSIX systems return the primary group of the webserver we're running under.
 272          * On other systems just returns null.
 273          *
 274          * This is used to advice the user that he should chgrp his config/data/images directory as the
 275          * webserver user before he can install.
 276          *
 277          * Public because SqliteInstaller needs it, and doesn't subclass Installer.
 278          *
 279          * @return mixed
 280          */
 281         public static function maybeGetWebserverPrimaryGroup() {
 282                 if ( !function_exists( 'posix_getegid' ) || !function_exists( 'posix_getpwuid' ) ) {
 283                         # I don't know this, this isn't UNIX.
 284                         return null;
 285                 }
 286
 287                 # posix_getegid() *not* getmygid() because we want the group of the webserver,
 288                 # not whoever owns the current script.
 289                 $gid = posix_getegid();
 290                 $getpwuid = posix_getpwuid( $gid );
 291                 $group = $getpwuid['name'];
 292
 293                 return $group;
 294         }
 295
 296         /**
 297          * Convert wikitext $text to HTML.
 298          *
 299          * This is potentially error prone since many parser features require a complete
 300          * installed MW database. The solution is to just not use those features when you
 301          * write your messages. This appears to work well enough. Basic formatting and
 302          * external links work just fine.
 303          *
 304          * But in case a translator decides to throw in a #ifexist or internal link or
 305          * whatever, this function is guarded to catch attempted DB access and to present
 306          * some fallback text.
 307          *
 308          * @param $text String
 309          * @param $lineStart Boolean
 310          * @return String
 311          */
 312         public function parse( $text, $lineStart = false ) {
 313                 global $wgParser;
 314
 315                 try {
 316                         $out = $wgParser->parse( $text, $this->parserTitle, $this->parserOptions, $lineStart );
 317                         $html = $out->getText();
 318                 } catch ( DBAccessError $e ) {
 319                         $html = '<!--DB access attempted during parse-->  ' . htmlspecialchars( $text );
 320
 321                         if ( !empty( $this->debug ) ) {
 322                                 $html .= "<!--\n" . $e->getTraceAsString() . "\n-->";
 323                         }
 324                 }
 325
 326                 return $html;
 327         }
 328
 329         /**
 330          * TODO: document
 331          *
 332          * @param $installer DatabaseInstaller
 333          *
 334          * @return Status
 335          */
 336         public function installDatabase( DatabaseInstaller &$installer ) {
 337                 if( !$installer ) {
 338                         $type = $this->getVar( 'wgDBtype' );
 339                         $status = Status::newFatal( "config-no-db", $type );
 340                 } else {
 341                         $status = $installer->setupDatabase();
 342                 }
 343
 344                 return $status;
 345         }
 346
 347         /**
 348          * TODO: document
 349          *
 350          * @param $installer DatabaseInstaller
 351          *
 352          * @return Status
 353          */
 354         public function installTables( DatabaseInstaller &$installer ) {
 355                 $status = $installer->createTables();
 356
 357                 if( $status->isOK() ) {
 358                         LBFactory::enableBackend();
 359                 }
 360
 361                 return $status;
 362         }
 363
 364         /**
 365          * TODO: document
 366          *
 367          * @param $installer DatabaseInstaller
 368          *
 369          * @return Status
 370          */
 371         public function installInterwiki( DatabaseInstaller &$installer ) {
 372                 return $installer->populateInterwikiTable();
 373         }
 374
 375         /**
 376          * Exports all wg* variables stored by the installer into global scope.
 377          */
 378         public function exportVars() {
 379                 foreach ( $this->settings as $name => $value ) {
 380                         if ( substr( $name, 0, 2 ) == 'wg' ) {
 381                                 $GLOBALS[$name] = $value;
 382                         }
 383                 }
 384         }
 385
 386         /**
 387          * Check if we're installing the latest version.
 388          */
 389         public function envLatestVersion() {
 390                 global $wgVersion;
 391
 392                 $repository = wfGetRepository();
 393                 $currentVersion = $repository->getLatestCoreVersion();
 394
 395                 $this->setVar( '_ExternalHTTP', true );
 396
 397                 if ( $currentVersion === false ) {
 398                         # For when the request is successful but there's e.g. some silly man in
 399                         # the middle firewall blocking us, e.g. one of those annoying airport ones
 400                         $this->showMessage( 'config-env-latest-can-not-check', $repository->getLocation() );
 401                         return;
 402                 }
 403
 404                 if( version_compare( $wgVersion, $currentVersion, '<' ) ) {
 405                         $this->showMessage( 'config-env-latest-old' );
 406                         // FIXME: this only works for the web installer!
 407                         $this->showHelpBox( 'config-env-latest-help', $wgVersion, $currentVersion );
 408                 } elseif( version_compare( $wgVersion, $currentVersion, '>' ) ) {
 409                         $this->showMessage( 'config-env-latest-new' );
 410                 }
 411
 412                 $this->showMessage( 'config-env-latest-ok' );
 413         }
 414
 415         /**
 416          * Environment check for DB types.
 417          */
 418         public function envCheckDB() {
 419                 global $wgLang;
 420
 421                 $compiledDBs = array();
 422                 $goodNames = array();
 423                 $allNames = array();
 424
 425                 foreach ( self::getDBTypes() as $name ) {
 426                         $db = $this->getDBInstaller( $name );
 427                         $readableName = wfMsg( 'config-type-' . $name );
 428
 429                         if ( $db->isCompiled() ) {
 430                                 $compiledDBs[] = $name;
 431                                 $goodNames[] = $readableName;
 432                         }
 433
 434                         $allNames[] = $readableName;
 435                 }
 436
 437                 $this->setVar( '_CompiledDBs', $compiledDBs );
 438
 439                 if ( !$compiledDBs ) {
 440                         $this->showMessage( 'config-no-db' );
 441                         // FIXME: this only works for the web installer!
 442                         $this->showHelpBox( 'config-no-db-help', $wgLang->commaList( $allNames ) );
 443                         return false;
 444                 }
 445
 446                 $this->showMessage( 'config-have-db', $wgLang->listToText( $goodNames ), count( $goodNames ) );
 447
 448                 // Check for FTS3 full-text search module
 449                 $sqlite = $this->getDBInstaller( 'sqlite' );
 450                 if ( $sqlite->isCompiled() ) {
 451                         $db = new DatabaseSqliteStandalone( ':memory:' );
 452                         $this->showMessage( $db->getFulltextSearchModule() == 'FTS3'
 453                                 ? 'config-have-fts3'
 454                                 : 'config-no-fts3'
 455                         );
 456                 }
 457         }
 458
 459         /**
 460          * Environment check for register_globals.
 461          */
 462         public function envCheckRegisterGlobals() {
 463                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 464                         $this->showMessage( 'config-register-globals' );
 465                 }
 466         }
 467
 468         /**
 469          * Environment check for magic_quotes_runtime.
 470          */
 471         public function envCheckMagicQuotes() {
 472                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 473                         $this->showMessage( 'config-magic-quotes-runtime' );
 474                         return false;
 475                 }
 476         }
 477
 478         /**
 479          * Environment check for magic_quotes_sybase.
 480          */
 481         public function envCheckMagicSybase() {
 482                 if ( wfIniGetBool( 'magic_quotes_sybase' ) ) {
 483                         $this->showMessage( 'config-magic-quotes-sybase' );
 484                         return false;
 485                 }
 486         }
 487
 488         /**
 489          * Environment check for mbstring.func_overload.
 490          */
 491         public function envCheckMbstring() {
 492                 if ( wfIniGetBool( 'mbstring.func_overload' ) ) {
 493                         $this->showMessage( 'config-mbstring' );
 494                         return false;
 495                 }
 496         }
 497
 498         /**
 499          * Environment check for zend.ze1_compatibility_mode.
 500          */
 501         public function envCheckZE1() {
 502                 if ( wfIniGetBool( 'zend.ze1_compatibility_mode' ) ) {
 503                         $this->showMessage( 'config-ze1' );
 504                         return false;
 505                 }
 506         }
 507
 508         /**
 509          * Environment check for safe_mode.
 510          */
 511         public function envCheckSafeMode() {
 512                 if ( wfIniGetBool( 'safe_mode' ) ) {
 513                         $this->setVar( '_SafeMode', true );
 514                         $this->showMessage( 'config-safe-mode' );
 515                 }
 516         }
 517
 518         /**
 519          * Environment check for the XML module.
 520          */
 521         public function envCheckXML() {
 522                 if ( !function_exists( "utf8_encode" ) ) {
 523                         $this->showMessage( 'config-xml-bad' );
 524                         return false;
 525                 }
 526                 $this->showMessage( 'config-xml-good' );
 527         }
 528
 529         /**
 530          * Environment check for the PCRE module.
 531          */
 532         public function envCheckPCRE() {
 533                 if ( !function_exists( 'preg_match' ) ) {
 534                         $this->showMessage( 'config-pcre' );
 535                         return false;
 536                 }
 537         }
 538
 539         /**
 540          * Environment check for available memory.
 541          */
 542         public function envCheckMemory() {
 543                 $limit = ini_get( 'memory_limit' );
 544
 545                 if ( !$limit || $limit == -1 ) {
 546                         $this->showMessage( 'config-memory-none' );
 547                         return true;
 548                 }
 549
 550                 $n = intval( $limit );
 551
 552                 if( preg_match( '/^([0-9]+)[Mm]$/', trim( $limit ), $m ) ) {
 553                         $n = intval( $m[1] * ( 1024 * 1024 ) );
 554                 }
 555
 556                 if( $n < $this->minMemorySize * 1024 * 1024 ) {
 557                         $newLimit = "{$this->minMemorySize}M";
 558
 559                         if( ini_set( "memory_limit", $newLimit ) === false ) {
 560                                 $this->showMessage( 'config-memory-bad', $limit );
 561                         } else {
 562                                 $this->showMessage( 'config-memory-raised', $limit, $newLimit );
 563                                 $this->setVar( '_RaiseMemory', true );
 564                         }
 565                 } else {
 566                         $this->showMessage( 'config-memory-ok', $limit );
 567                 }
 568         }
 569
 570         /**
 571          * Environment check for compiled object cache types.
 572          */
 573         public function envCheckCache() {
 574                 $caches = array();
 575
 576                 foreach ( $this->objectCaches as $name => $function ) {
 577                         if ( function_exists( $function ) ) {
 578                                 $caches[$name] = true;
 579                                 $this->showMessage( 'config-' . $name );
 580                         }
 581                 }
 582
 583                 if ( !$caches ) {
 584                         $this->showMessage( 'config-no-cache' );
 585                 }
 586
 587                 $this->setVar( '_Caches', $caches );
 588         }
 589
 590         /**
 591          * Search for GNU diff3.
 592          */
 593         public function envCheckDiff3() {
 594                 $names = array( "gdiff3", "diff3", "diff3.exe" );
 595                 $versionInfo = array( '$1 --version 2>&1', 'diff3 (GNU diffutils)' );
 596
 597                 $diff3 = $this->locateExecutableInDefaultPaths( $names, $versionInfo );
 598
 599                 if ( $diff3 ) {
 600                         $this->showMessage( 'config-diff3-good', $diff3 );
 601                         $this->setVar( 'wgDiff3', $diff3 );
 602                 } else {
 603                         $this->setVar( 'wgDiff3', false );
 604                         $this->showMessage( 'config-diff3-bad' );
 605                 }
 606         }
 607
 608         /**
 609          * Environment check for ImageMagick and GD.
 610          */
 611         public function envCheckGraphics() {
 612                 $names = array( wfIsWindows() ? 'convert.exe' : 'convert' );
 613                 $convert = $this->locateExecutableInDefaultPaths( $names, array( '$1 -version', 'ImageMagick' ) );
 614
 615                 if ( $convert ) {
 616                         $this->setVar( 'wgImageMagickConvertCommand', $convert );
 617                         $this->showMessage( 'config-imagemagick', $convert );
 618                         return true;
 619                 } elseif ( function_exists( 'imagejpeg' ) ) {
 620                         $this->showMessage( 'config-gd' );
 621                         return true;
 622                 } else {
 623                         $this->showMessage( 'no-scaling' );
 624                 }
 625         }
 626
 627         /**
 628          * Environment check for setting $IP and $wgScriptPath.
 629          */
 630         public function envCheckPath() {
 631                 global $IP;
 632                 $IP = dirname( dirname( dirname( __FILE__ ) ) );
 633
 634                 $this->setVar( 'IP', $IP );
 635                 $this->showMessage( 'config-dir', $IP );
 636
 637                 // PHP_SELF isn't available sometimes, such as when PHP is CGI but
 638                 // cgi.fix_pathinfo is disabled. In that case, fall back to SCRIPT_NAME
 639                 // to get the path to the current script... hopefully it's reliable. SIGH
 640                 if ( !empty( $_SERVER['PHP_SELF'] ) ) {
 641                         $path = $_SERVER['PHP_SELF'];
 642                 } elseif ( !empty( $_SERVER['SCRIPT_NAME'] ) ) {
 643                         $path = $_SERVER['SCRIPT_NAME'];
 644                 } elseif ( $this->getVar( 'wgScriptPath' ) ) {
 645                         // Some kind soul has set it for us already (e.g. debconf)
 646                         return true;
 647                 } else {
 648                         $this->showMessage( 'config-no-uri' );
 649                         return false;
 650                 }
 651
 652                 $uri = preg_replace( '{^(.*)/config.*$}', '$1', $path );
 653                 $this->setVar( 'wgScriptPath', $uri );
 654                 $this->showMessage( 'config-uri', $uri );
 655         }
 656
 657         /**
 658          * Environment check for writable config/ directory.
 659          */
 660         public function envCheckWriteableDir() {
 661                 $ipDir = $this->getVar( 'IP' );
 662                 $configDir = $ipDir . '/config';
 663
 664                 if( !is_writeable( $configDir ) ) {
 665                         $webserverGroup = self::maybeGetWebserverPrimaryGroup();
 666
 667                         if ( $webserverGroup !== null ) {
 668                                 $this->showMessage( 'config-dir-not-writable-group', $ipDir, $webserverGroup );
 669                         } else {
 670                                 $this->showMessage( 'config-dir-not-writable-nogroup', $ipDir, $webserverGroup );
 671                         }
 672
 673                         return false;
 674                 }
 675         }
 676
 677         /**
 678          * Environment check for setting the preferred PHP file extension.
 679          */
 680         public function envCheckExtension() {
 681                 // FIXME: detect this properly
 682                 if ( defined( 'MW_INSTALL_PHP5_EXT' ) ) {
 683                         $ext = 'php5';
 684                 } else {
 685                         $ext = 'php';
 686                 }
 687
 688                 $this->setVar( 'wgScriptExtension', ".$ext" );
 689                 $this->showMessage( 'config-file-extension', $ext );
 690         }
 691
 692         /**
 693          * TODO: document
 694          */
 695         public function envCheckShellLocale() {
 696                 $os = php_uname( 's' );
 697                 $supported = array( 'Linux', 'SunOS', 'HP-UX', 'Darwin' ); # Tested these
 698
 699                 if ( !in_array( $os, $supported ) ) {
 700                         return true;
 701                 }
 702
 703                 # Get a list of available locales.
 704                 $lines = $ret = false;
 705                 $lines = wfShellExec( '/usr/bin/locale -a', $ret );
 706
 707                 if ( $ret ) {
 708                         return true;
 709                 }
 710
 711                 $lines = wfArrayMap( 'trim', explode( "\n", $lines ) );
 712                 $candidatesByLocale = array();
 713                 $candidatesByLang = array();
 714
 715                 foreach ( $lines as $line ) {
 716                         if ( $line === '' ) {
 717                                 continue;
 718                         }
 719
 720                         if ( !preg_match( '/^([a-zA-Z]+)(_[a-zA-Z]+|)\.(utf8|UTF-8)(@[a-zA-Z_]*|)$/i', $line, $m ) ) {
 721                                 continue;
 722                         }
 723
 724                         list( $all, $lang, $territory, $charset, $modifier ) = $m;
 725
 726                         $candidatesByLocale[$m[0]] = $m;
 727                         $candidatesByLang[$lang][] = $m;
 728                 }
 729
 730                 # Try the current value of LANG.
 731                 if ( isset( $candidatesByLocale[ getenv( 'LANG' ) ] ) ) {
 732                         $this->setVar( 'wgShellLocale', getenv( 'LANG' ) );
 733                         $this->showMessage( 'config-shell-locale', getenv( 'LANG' ) );
 734                         return true;
 735                 }
 736
 737                 # Try the most common ones.
 738                 $commonLocales = array( 'en_US.UTF-8', 'en_US.utf8', 'de_DE.UTF-8', 'de_DE.utf8' );
 739                 foreach ( $commonLocales as $commonLocale ) {
 740                         if ( isset( $candidatesByLocale[$commonLocale] ) ) {
 741                                 $this->setVar( 'wgShellLocale', $commonLocale );
 742                                 $this->showMessage( 'config-shell-locale', $commonLocale );
 743                                 return true;
 744                         }
 745                 }
 746
 747                 # Is there an available locale in the Wiki's language?
 748                 $wikiLang = $this->getVar( 'wgLanguageCode' );
 749
 750                 if ( isset( $candidatesByLang[$wikiLang] ) ) {
 751                         $m = reset( $candidatesByLang[$wikiLang] );
 752                         $this->setVar( 'wgShellLocale', $m[0] );
 753                         $this->showMessage( 'config-shell-locale', $m[0] );
 754                         return true;
 755                 }
 756
 757                 # Are there any at all?
 758                 if ( count( $candidatesByLocale ) ) {
 759                         $m = reset( $candidatesByLocale );
 760                         $this->setVar( 'wgShellLocale', $m[0] );
 761                         $this->showMessage( 'config-shell-locale', $m[0] );
 762                         return true;
 763                 }
 764
 765                 # Give up.
 766                 return true;
 767         }
 768
 769         /**
 770          * TODO: document
 771          */
 772         public function envCheckUploadsDirectory() {
 773                 global $IP, $wgServer;
 774
 775                 $dir = $IP . '/images/';
 776                 $url = $wgServer . $this->getVar( 'wgScriptPath' ) . '/images/';
 777                 $safe = !$this->dirIsExecutable( $dir, $url );
 778
 779                 if ( $safe ) {
 780                         $this->showMessage( 'config-uploads-safe' );
 781                 } else {
 782                         $this->showMessage( 'config-uploads-not-safe', $dir );
 783                 }
 784         }
 785
 786         /**
 787          * Convert a hex string representing a Unicode code point to that code point.
 788          * @param $c String
 789          * @return string
 790          */
 791         protected function unicodeChar( $c ) {
 792                 $c = hexdec($c);
 793                 if ($c <= 0x7F) {
 794                         return chr($c);
 795                 } else if ($c <= 0x7FF) {
 796                         return chr(0xC0 | $c >> 6) . chr(0x80 | $c & 0x3F);
 797                 } else if ($c <= 0xFFFF) {
 798                         return chr(0xE0 | $c >> 12) . chr(0x80 | $c >> 6 & 0x3F)
 799                                 . chr(0x80 | $c & 0x3F);
 800                 } else if ($c <= 0x10FFFF) {
 801                         return chr(0xF0 | $c >> 18) . chr(0x80 | $c >> 12 & 0x3F)
 802                                 . chr(0x80 | $c >> 6 & 0x3F)
 803                                 . chr(0x80 | $c & 0x3F);
 804                 } else {
 805                         return false;
 806                 }
 807         }
 808
 809
 810         /**
 811          * Check the libicu version
 812          */
 813         public function envCheckLibicu() {
 814                 $utf8 = function_exists( 'utf8_normalize' );
 815                 $intl = function_exists( 'normalizer_normalize' );
 816
 817                 /**
 818                  * This needs to be updated something that the latest libicu
 819                  * will properly normalize.  This normalization was found at
 820                  * http://www.unicode.org/versions/Unicode5.2.0/#Character_Additions
 821                  * Note that we use the hex representation to create the code
 822                  * points in order to avoid any Unicode-destroying during transit.
 823                  */
 824                 $not_normal_c = $this->unicodeChar("FA6C");
 825                 $normal_c = $this->unicodeChar("242EE");
 826
 827                 $useNormalizer = 'php';
 828                 $needsUpdate = false;
 829
 830                 /**
 831                  * We're going to prefer the pecl extension here unless
 832                  * utf8_normalize is more up to date.
 833                  */
 834                 if( $utf8 ) {
 835                         $useNormalizer = 'utf8';
 836                         $utf8 = utf8_normalize( $not_normal_c, UNORM_NFC );
 837                         if ( $utf8 !== $normal_c ) $needsUpdate = true;
 838                 }
 839                 if( $intl ) {
 840                         $useNormalizer = 'intl';
 841                         $intl = normalizer_normalize( $not_normal_c, Normalizer::FORM_C );
 842                         if ( $intl !== $normal_c ) $needsUpdate = true;
 843                 }
 844
 845                 // Uses messages 'config-unicode-using-php', 'config-unicode-using-utf8', 'config-unicode-using-intl'
 846                 $this->showMessage( 'config-unicode-using-' . $useNormalizer );
 847                 if( $useNormalizer === 'php' ) {
 848                         $this->showMessage( 'config-unicode-pure-php-warning' );
 849                 } elseif( $needsUpdate ) {
 850                         $this->showMessage( 'config-unicode-update-warning' );
 851                 }
 852         }
 853
 854         /**
 855          * Get an array of likely places we can find executables. Check a bunch
 856          * of known Unix-like defaults, as well as the PATH environment variable
 857          * (which should maybe make it work for Windows?)
 858          *
 859          * @return Array
 860          */
 861         protected function getPossibleBinPaths() {
 862                 return array_merge(
 863                         array( '/usr/bin', '/usr/local/bin', '/opt/csw/bin',
 864                                 '/usr/gnu/bin', '/usr/sfw/bin', '/sw/bin', '/opt/local/bin' ),
 865                         explode( PATH_SEPARATOR, getenv( 'PATH' ) )
 866                 );
 867         }
 868
 869         /**
 870          * Search a path for any of the given executable names. Returns the
 871          * executable name if found. Also checks the version string returned
 872          * by each executable.
 873          *
 874          * Used only by environment checks.
 875          *
 876          * @param $path String: path to search
 877          * @param $names Array of executable names
 878          * @param $versionInfo Boolean false or array with two members:
 879          *               0 => Command to run for version check, with $1 for the path
 880          *               1 => String to compare the output with
 881          *
 882          * If $versionInfo is not false, only executables with a version
 883          * matching $versionInfo[1] will be returned.
 884          */
 885         protected function locateExecutable( $path, $names, $versionInfo = false ) {
 886                 if ( !is_array( $names ) ) {
 887                         $names = array( $names );
 888                 }
 889
 890                 foreach ( $names as $name ) {
 891                         $command = $path . DIRECTORY_SEPARATOR . $name;
 892
 893                         wfSuppressWarnings();
 894                         $file_exists = file_exists( $command );
 895                         wfRestoreWarnings();
 896
 897                         if ( $file_exists ) {
 898                                 if ( !$versionInfo ) {
 899                                         return $command;
 900                                 }
 901
 902                                 if ( wfIsWindows() ) {
 903                                         $command = "\"$command\"";
 904                                 }
 905                                 $file = str_replace( '$1', $command, $versionInfo[0] );
 906                                 if ( strstr( wfShellExec( $file ), $versionInfo[1]) !== false ) {
 907                                         return $command;
 908                                 }
 909                         }
 910                 }
 911                 return false;
 912         }
 913
 914         /**
 915          * Same as locateExecutable(), but checks in getPossibleBinPaths() by default
 916          * @see locateExecutable()
 917          */
 918         protected function locateExecutableInDefaultPaths( $names, $versionInfo = false ) {
 919                 foreach( $this->getPossibleBinPaths() as $path ) {
 920                         $exe = $this->locateExecutable( $path, $names, $versionInfo );
 921                         if( $exe !== false ) {
 922                                 return $exe;
 923                         }
 924                 }
 925                 return false;
 926         }
 927
 928         /**
 929          * Checks if scripts located in the given directory can be executed via the given URL.
 930          *
 931          * Used only by environment checks.
 932          */
 933         public function dirIsExecutable( $dir, $url ) {
 934                 $scriptTypes = array(
 935                         'php' => array(
 936                                 "<?php echo 'ex' . 'ec';",
 937                                 "#!/var/env php5\n<?php echo 'ex' . 'ec';",
 938                         ),
 939                 );
 940
 941                 // it would be good to check other popular languages here, but it'll be slow.
 942
 943                 wfSuppressWarnings();
 944
 945                 foreach ( $scriptTypes as $ext => $contents ) {
 946                         foreach ( $contents as $source ) {
 947                                 $file = 'exectest.' . $ext;
 948
 949                                 if ( !file_put_contents( $dir . $file, $source ) ) {
 950                                         break;
 951                                 }
 952
 953                                 $text = Http::get( $url . $file );
 954                                 unlink( $dir . $file );
 955
 956                                 if ( $text == 'exec' ) {
 957                                         wfRestoreWarnings();
 958                                         return $ext;
 959                                 }
 960                         }
 961                 }
 962
 963                 wfRestoreWarnings();
 964
 965                 return false;
 966         }
 967
 968 }