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          * TODO: document
 377          *
 378          * @param $installer DatabaseInstaller
 379          *
 380          * @return Status
 381          */
 382         public function installMainpage( DatabaseInstaller &$installer ) {
 383                 return $installer->createMainpage();
 384         }
 385
 386         /**
 387          * Exports all wg* variables stored by the installer into global scope.
 388          */
 389         public function exportVars() {
 390                 foreach ( $this->settings as $name => $value ) {
 391                         if ( substr( $name, 0, 2 ) == 'wg' ) {
 392                                 $GLOBALS[$name] = $value;
 393                         }
 394                 }
 395         }
 396
 397         /**
 398          * Check if we're installing the latest version.
 399          */
 400         public function envLatestVersion() {
 401                 global $wgVersion;
 402
 403                 $repository = wfGetRepository();
 404                 $currentVersion = $repository->getLatestCoreVersion();
 405
 406                 $this->setVar( '_ExternalHTTP', true );
 407
 408                 if ( $currentVersion === false ) {
 409                         # For when the request is successful but there's e.g. some silly man in
 410                         # the middle firewall blocking us, e.g. one of those annoying airport ones
 411                         $this->showMessage( 'config-env-latest-can-not-check', $repository->getLocation() );
 412                         return;
 413                 }
 414
 415                 if( version_compare( $wgVersion, $currentVersion, '<' ) ) {
 416                         $this->showMessage( 'config-env-latest-old' );
 417                         // FIXME: this only works for the web installer!
 418                         $this->showHelpBox( 'config-env-latest-help', $wgVersion, $currentVersion );
 419                 } elseif( version_compare( $wgVersion, $currentVersion, '>' ) ) {
 420                         $this->showMessage( 'config-env-latest-new' );
 421                 }
 422
 423                 $this->showMessage( 'config-env-latest-ok' );
 424         }
 425
 426         /**
 427          * Environment check for DB types.
 428          */
 429         public function envCheckDB() {
 430                 global $wgLang;
 431
 432                 $compiledDBs = array();
 433                 $goodNames = array();
 434                 $allNames = array();
 435
 436                 foreach ( self::getDBTypes() as $name ) {
 437                         $db = $this->getDBInstaller( $name );
 438                         $readableName = wfMsg( 'config-type-' . $name );
 439
 440                         if ( $db->isCompiled() ) {
 441                                 $compiledDBs[] = $name;
 442                                 $goodNames[] = $readableName;
 443                         }
 444
 445                         $allNames[] = $readableName;
 446                 }
 447
 448                 $this->setVar( '_CompiledDBs', $compiledDBs );
 449
 450                 if ( !$compiledDBs ) {
 451                         $this->showMessage( 'config-no-db' );
 452                         // FIXME: this only works for the web installer!
 453                         $this->showHelpBox( 'config-no-db-help', $wgLang->commaList( $allNames ) );
 454                         return false;
 455                 }
 456
 457                 $this->showMessage( 'config-have-db', $wgLang->listToText( $goodNames ), count( $goodNames ) );
 458
 459                 // Check for FTS3 full-text search module
 460                 $sqlite = $this->getDBInstaller( 'sqlite' );
 461                 if ( $sqlite->isCompiled() ) {
 462                         $db = new DatabaseSqliteStandalone( ':memory:' );
 463                         $this->showMessage( $db->getFulltextSearchModule() == 'FTS3'
 464                                 ? 'config-have-fts3'
 465                                 : 'config-no-fts3'
 466                         );
 467                 }
 468         }
 469
 470         /**
 471          * Environment check for register_globals.
 472          */
 473         public function envCheckRegisterGlobals() {
 474                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 475                         $this->showMessage( 'config-register-globals' );
 476                 }
 477         }
 478
 479         /**
 480          * Environment check for magic_quotes_runtime.
 481          */
 482         public function envCheckMagicQuotes() {
 483                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 484                         $this->showMessage( 'config-magic-quotes-runtime' );
 485                         return false;
 486                 }
 487         }
 488
 489         /**
 490          * Environment check for magic_quotes_sybase.
 491          */
 492         public function envCheckMagicSybase() {
 493                 if ( wfIniGetBool( 'magic_quotes_sybase' ) ) {
 494                         $this->showMessage( 'config-magic-quotes-sybase' );
 495                         return false;
 496                 }
 497         }
 498
 499         /**
 500          * Environment check for mbstring.func_overload.
 501          */
 502         public function envCheckMbstring() {
 503                 if ( wfIniGetBool( 'mbstring.func_overload' ) ) {
 504                         $this->showMessage( 'config-mbstring' );
 505                         return false;
 506                 }
 507         }
 508
 509         /**
 510          * Environment check for zend.ze1_compatibility_mode.
 511          */
 512         public function envCheckZE1() {
 513                 if ( wfIniGetBool( 'zend.ze1_compatibility_mode' ) ) {
 514                         $this->showMessage( 'config-ze1' );
 515                         return false;
 516                 }
 517         }
 518
 519         /**
 520          * Environment check for safe_mode.
 521          */
 522         public function envCheckSafeMode() {
 523                 if ( wfIniGetBool( 'safe_mode' ) ) {
 524                         $this->setVar( '_SafeMode', true );
 525                         $this->showMessage( 'config-safe-mode' );
 526                 }
 527         }
 528
 529         /**
 530          * Environment check for the XML module.
 531          */
 532         public function envCheckXML() {
 533                 if ( !function_exists( "utf8_encode" ) ) {
 534                         $this->showMessage( 'config-xml-bad' );
 535                         return false;
 536                 }
 537                 $this->showMessage( 'config-xml-good' );
 538         }
 539
 540         /**
 541          * Environment check for the PCRE module.
 542          */
 543         public function envCheckPCRE() {
 544                 if ( !function_exists( 'preg_match' ) ) {
 545                         $this->showMessage( 'config-pcre' );
 546                         return false;
 547                 }
 548         }
 549
 550         /**
 551          * Environment check for available memory.
 552          */
 553         public function envCheckMemory() {
 554                 $limit = ini_get( 'memory_limit' );
 555
 556                 if ( !$limit || $limit == -1 ) {
 557                         $this->showMessage( 'config-memory-none' );
 558                         return true;
 559                 }
 560
 561                 $n = intval( $limit );
 562
 563                 if( preg_match( '/^([0-9]+)[Mm]$/', trim( $limit ), $m ) ) {
 564                         $n = intval( $m[1] * ( 1024 * 1024 ) );
 565                 }
 566
 567                 if( $n < $this->minMemorySize * 1024 * 1024 ) {
 568                         $newLimit = "{$this->minMemorySize}M";
 569
 570                         if( ini_set( "memory_limit", $newLimit ) === false ) {
 571                                 $this->showMessage( 'config-memory-bad', $limit );
 572                         } else {
 573                                 $this->showMessage( 'config-memory-raised', $limit, $newLimit );
 574                                 $this->setVar( '_RaiseMemory', true );
 575                         }
 576                 } else {
 577                         $this->showMessage( 'config-memory-ok', $limit );
 578                 }
 579         }
 580
 581         /**
 582          * Environment check for compiled object cache types.
 583          */
 584         public function envCheckCache() {
 585                 $caches = array();
 586
 587                 foreach ( $this->objectCaches as $name => $function ) {
 588                         if ( function_exists( $function ) ) {
 589                                 $caches[$name] = true;
 590                                 $this->showMessage( 'config-' . $name );
 591                         }
 592                 }
 593
 594                 if ( !$caches ) {
 595                         $this->showMessage( 'config-no-cache' );
 596                 }
 597
 598                 $this->setVar( '_Caches', $caches );
 599         }
 600
 601         /**
 602          * Search for GNU diff3.
 603          */
 604         public function envCheckDiff3() {
 605                 $names = array( "gdiff3", "diff3", "diff3.exe" );
 606                 $versionInfo = array( '$1 --version 2>&1', 'diff3 (GNU diffutils)' );
 607
 608                 $diff3 = $this->locateExecutableInDefaultPaths( $names, $versionInfo );
 609
 610                 if ( $diff3 ) {
 611                         $this->showMessage( 'config-diff3-good', $diff3 );
 612                         $this->setVar( 'wgDiff3', $diff3 );
 613                 } else {
 614                         $this->setVar( 'wgDiff3', false );
 615                         $this->showMessage( 'config-diff3-bad' );
 616                 }
 617         }
 618
 619         /**
 620          * Environment check for ImageMagick and GD.
 621          */
 622         public function envCheckGraphics() {
 623                 $names = array( wfIsWindows() ? 'convert.exe' : 'convert' );
 624                 $convert = $this->locateExecutableInDefaultPaths( $names, array( '$1 -version', 'ImageMagick' ) );
 625
 626                 if ( $convert ) {
 627                         $this->setVar( 'wgImageMagickConvertCommand', $convert );
 628                         $this->showMessage( 'config-imagemagick', $convert );
 629                         return true;
 630                 } elseif ( function_exists( 'imagejpeg' ) ) {
 631                         $this->showMessage( 'config-gd' );
 632                         return true;
 633                 } else {
 634                         $this->showMessage( 'no-scaling' );
 635                 }
 636         }
 637
 638         /**
 639          * Environment check for setting $IP and $wgScriptPath.
 640          */
 641         public function envCheckPath() {
 642                 global $IP;
 643                 $IP = dirname( dirname( dirname( __FILE__ ) ) );
 644
 645                 $this->setVar( 'IP', $IP );
 646                 $this->showMessage( 'config-dir', $IP );
 647
 648                 // PHP_SELF isn't available sometimes, such as when PHP is CGI but
 649                 // cgi.fix_pathinfo is disabled. In that case, fall back to SCRIPT_NAME
 650                 // to get the path to the current script... hopefully it's reliable. SIGH
 651                 if ( !empty( $_SERVER['PHP_SELF'] ) ) {
 652                         $path = $_SERVER['PHP_SELF'];
 653                 } elseif ( !empty( $_SERVER['SCRIPT_NAME'] ) ) {
 654                         $path = $_SERVER['SCRIPT_NAME'];
 655                 } elseif ( $this->getVar( 'wgScriptPath' ) ) {
 656                         // Some kind soul has set it for us already (e.g. debconf)
 657                         return true;
 658                 } else {
 659                         $this->showMessage( 'config-no-uri' );
 660                         return false;
 661                 }
 662
 663                 $uri = preg_replace( '{^(.*)/config.*$}', '$1', $path );
 664                 $this->setVar( 'wgScriptPath', $uri );
 665                 $this->showMessage( 'config-uri', $uri );
 666         }
 667
 668         /**
 669          * Environment check for writable config/ directory.
 670          */
 671         public function envCheckWriteableDir() {
 672                 $ipDir = $this->getVar( 'IP' );
 673                 $configDir = $ipDir . '/config';
 674
 675                 if( !is_writeable( $configDir ) ) {
 676                         $webserverGroup = self::maybeGetWebserverPrimaryGroup();
 677
 678                         if ( $webserverGroup !== null ) {
 679                                 $this->showMessage( 'config-dir-not-writable-group', $ipDir, $webserverGroup );
 680                         } else {
 681                                 $this->showMessage( 'config-dir-not-writable-nogroup', $ipDir, $webserverGroup );
 682                         }
 683
 684                         return false;
 685                 }
 686         }
 687
 688         /**
 689          * Environment check for setting the preferred PHP file extension.
 690          */
 691         public function envCheckExtension() {
 692                 // FIXME: detect this properly
 693                 if ( defined( 'MW_INSTALL_PHP5_EXT' ) ) {
 694                         $ext = 'php5';
 695                 } else {
 696                         $ext = 'php';
 697                 }
 698
 699                 $this->setVar( 'wgScriptExtension', ".$ext" );
 700                 $this->showMessage( 'config-file-extension', $ext );
 701         }
 702
 703         /**
 704          * TODO: document
 705          */
 706         public function envCheckShellLocale() {
 707                 $os = php_uname( 's' );
 708                 $supported = array( 'Linux', 'SunOS', 'HP-UX', 'Darwin' ); # Tested these
 709
 710                 if ( !in_array( $os, $supported ) ) {
 711                         return true;
 712                 }
 713
 714                 # Get a list of available locales.
 715                 $lines = $ret = false;
 716                 $lines = wfShellExec( '/usr/bin/locale -a', $ret );
 717
 718                 if ( $ret ) {
 719                         return true;
 720                 }
 721
 722                 $lines = wfArrayMap( 'trim', explode( "\n", $lines ) );
 723                 $candidatesByLocale = array();
 724                 $candidatesByLang = array();
 725
 726                 foreach ( $lines as $line ) {
 727                         if ( $line === '' ) {
 728                                 continue;
 729                         }
 730
 731                         if ( !preg_match( '/^([a-zA-Z]+)(_[a-zA-Z]+|)\.(utf8|UTF-8)(@[a-zA-Z_]*|)$/i', $line, $m ) ) {
 732                                 continue;
 733                         }
 734
 735                         list( $all, $lang, $territory, $charset, $modifier ) = $m;
 736
 737                         $candidatesByLocale[$m[0]] = $m;
 738                         $candidatesByLang[$lang][] = $m;
 739                 }
 740
 741                 # Try the current value of LANG.
 742                 if ( isset( $candidatesByLocale[ getenv( 'LANG' ) ] ) ) {
 743                         $this->setVar( 'wgShellLocale', getenv( 'LANG' ) );
 744                         $this->showMessage( 'config-shell-locale', getenv( 'LANG' ) );
 745                         return true;
 746                 }
 747
 748                 # Try the most common ones.
 749                 $commonLocales = array( 'en_US.UTF-8', 'en_US.utf8', 'de_DE.UTF-8', 'de_DE.utf8' );
 750                 foreach ( $commonLocales as $commonLocale ) {
 751                         if ( isset( $candidatesByLocale[$commonLocale] ) ) {
 752                                 $this->setVar( 'wgShellLocale', $commonLocale );
 753                                 $this->showMessage( 'config-shell-locale', $commonLocale );
 754                                 return true;
 755                         }
 756                 }
 757
 758                 # Is there an available locale in the Wiki's language?
 759                 $wikiLang = $this->getVar( 'wgLanguageCode' );
 760
 761                 if ( isset( $candidatesByLang[$wikiLang] ) ) {
 762                         $m = reset( $candidatesByLang[$wikiLang] );
 763                         $this->setVar( 'wgShellLocale', $m[0] );
 764                         $this->showMessage( 'config-shell-locale', $m[0] );
 765                         return true;
 766                 }
 767
 768                 # Are there any at all?
 769                 if ( count( $candidatesByLocale ) ) {
 770                         $m = reset( $candidatesByLocale );
 771                         $this->setVar( 'wgShellLocale', $m[0] );
 772                         $this->showMessage( 'config-shell-locale', $m[0] );
 773                         return true;
 774                 }
 775
 776                 # Give up.
 777                 return true;
 778         }
 779
 780         /**
 781          * TODO: document
 782          */
 783         public function envCheckUploadsDirectory() {
 784                 global $IP, $wgServer;
 785
 786                 $dir = $IP . '/images/';
 787                 $url = $wgServer . $this->getVar( 'wgScriptPath' ) . '/images/';
 788                 $safe = !$this->dirIsExecutable( $dir, $url );
 789
 790                 if ( $safe ) {
 791                         $this->showMessage( 'config-uploads-safe' );
 792                 } else {
 793                         $this->showMessage( 'config-uploads-not-safe', $dir );
 794                 }
 795         }
 796
 797         /**
 798          * Convert a hex string representing a Unicode code point to that code point.
 799          * @param $c String
 800          * @return string
 801          */
 802         protected function unicodeChar( $c ) {
 803                 $c = hexdec($c);
 804                 if ($c <= 0x7F) {
 805                         return chr($c);
 806                 } else if ($c <= 0x7FF) {
 807                         return chr(0xC0 | $c >> 6) . chr(0x80 | $c & 0x3F);
 808                 } else if ($c <= 0xFFFF) {
 809                         return chr(0xE0 | $c >> 12) . chr(0x80 | $c >> 6 & 0x3F)
 810                                 . chr(0x80 | $c & 0x3F);
 811                 } else if ($c <= 0x10FFFF) {
 812                         return chr(0xF0 | $c >> 18) . chr(0x80 | $c >> 12 & 0x3F)
 813                                 . chr(0x80 | $c >> 6 & 0x3F)
 814                                 . chr(0x80 | $c & 0x3F);
 815                 } else {
 816                         return false;
 817                 }
 818         }
 819
 820
 821         /**
 822          * Check the libicu version
 823          */
 824         public function envCheckLibicu() {
 825                 $utf8 = function_exists( 'utf8_normalize' );
 826                 $intl = function_exists( 'normalizer_normalize' );
 827
 828                 /**
 829                  * This needs to be updated something that the latest libicu
 830                  * will properly normalize.  This normalization was found at
 831                  * http://www.unicode.org/versions/Unicode5.2.0/#Character_Additions
 832                  * Note that we use the hex representation to create the code
 833                  * points in order to avoid any Unicode-destroying during transit.
 834                  */
 835                 $not_normal_c = $this->unicodeChar("FA6C");
 836                 $normal_c = $this->unicodeChar("242EE");
 837
 838                 $useNormalizer = 'php';
 839                 $needsUpdate = false;
 840
 841                 /**
 842                  * We're going to prefer the pecl extension here unless
 843                  * utf8_normalize is more up to date.
 844                  */
 845                 if( $utf8 ) {
 846                         $useNormalizer = 'utf8';
 847                         $utf8 = utf8_normalize( $not_normal_c, UNORM_NFC );
 848                         if ( $utf8 !== $normal_c ) $needsUpdate = true;
 849                 }
 850                 if( $intl ) {
 851                         $useNormalizer = 'intl';
 852                         $intl = normalizer_normalize( $not_normal_c, Normalizer::FORM_C );
 853                         if ( $intl !== $normal_c ) $needsUpdate = true;
 854                 }
 855
 856                 // Uses messages 'config-unicode-using-php', 'config-unicode-using-utf8', 'config-unicode-using-intl'
 857                 $this->showMessage( 'config-unicode-using-' . $useNormalizer );
 858                 if( $useNormalizer === 'php' ) {
 859                         $this->showMessage( 'config-unicode-pure-php-warning' );
 860                 } elseif( $needsUpdate ) {
 861                         $this->showMessage( 'config-unicode-update-warning' );
 862                 }
 863         }
 864
 865         /**
 866          * Get an array of likely places we can find executables. Check a bunch
 867          * of known Unix-like defaults, as well as the PATH environment variable
 868          * (which should maybe make it work for Windows?)
 869          *
 870          * @return Array
 871          */
 872         protected function getPossibleBinPaths() {
 873                 return array_merge(
 874                         array( '/usr/bin', '/usr/local/bin', '/opt/csw/bin',
 875                                 '/usr/gnu/bin', '/usr/sfw/bin', '/sw/bin', '/opt/local/bin' ),
 876                         explode( PATH_SEPARATOR, getenv( 'PATH' ) )
 877                 );
 878         }
 879
 880         /**
 881          * Search a path for any of the given executable names. Returns the
 882          * executable name if found. Also checks the version string returned
 883          * by each executable.
 884          *
 885          * Used only by environment checks.
 886          *
 887          * @param $path String: path to search
 888          * @param $names Array of executable names
 889          * @param $versionInfo Boolean false or array with two members:
 890          *               0 => Command to run for version check, with $1 for the path
 891          *               1 => String to compare the output with
 892          *
 893          * If $versionInfo is not false, only executables with a version
 894          * matching $versionInfo[1] will be returned.
 895          */
 896         protected function locateExecutable( $path, $names, $versionInfo = false ) {
 897                 if ( !is_array( $names ) ) {
 898                         $names = array( $names );
 899                 }
 900
 901                 foreach ( $names as $name ) {
 902                         $command = $path . DIRECTORY_SEPARATOR . $name;
 903
 904                         wfSuppressWarnings();
 905                         $file_exists = file_exists( $command );
 906                         wfRestoreWarnings();
 907
 908                         if ( $file_exists ) {
 909                                 if ( !$versionInfo ) {
 910                                         return $command;
 911                                 }
 912
 913                                 if ( wfIsWindows() ) {
 914                                         $command = "\"$command\"";
 915                                 }
 916                                 $file = str_replace( '$1', $command, $versionInfo[0] );
 917                                 if ( strstr( wfShellExec( $file ), $versionInfo[1]) !== false ) {
 918                                         return $command;
 919                                 }
 920                         }
 921                 }
 922                 return false;
 923         }
 924
 925         /**
 926          * Same as locateExecutable(), but checks in getPossibleBinPaths() by default
 927          * @see locateExecutable()
 928          */
 929         protected function locateExecutableInDefaultPaths( $names, $versionInfo = false ) {
 930                 foreach( $this->getPossibleBinPaths() as $path ) {
 931                         $exe = $this->locateExecutable( $path, $names, $versionInfo );
 932                         if( $exe !== false ) {
 933                                 return $exe;
 934                         }
 935                 }
 936                 return false;
 937         }
 938
 939         /**
 940          * Checks if scripts located in the given directory can be executed via the given URL.
 941          *
 942          * Used only by environment checks.
 943          */
 944         public function dirIsExecutable( $dir, $url ) {
 945                 $scriptTypes = array(
 946                         'php' => array(
 947                                 "<?php echo 'ex' . 'ec';",
 948                                 "#!/var/env php5\n<?php echo 'ex' . 'ec';",
 949                         ),
 950                 );
 951
 952                 // it would be good to check other popular languages here, but it'll be slow.
 953
 954                 wfSuppressWarnings();
 955
 956                 foreach ( $scriptTypes as $ext => $contents ) {
 957                         foreach ( $contents as $source ) {
 958                                 $file = 'exectest.' . $ext;
 959
 960                                 if ( !file_put_contents( $dir . $file, $source ) ) {
 961                                         break;
 962                                 }
 963
 964                                 $text = Http::get( $url . $file );
 965                                 unlink( $dir . $file );
 966
 967                                 if ( $text == 'exec' ) {
 968                                         wfRestoreWarnings();
 969                                         return $ext;
 970                                 }
 971                         }
 972                 }
 973
 974                 wfRestoreWarnings();
 975
 976                 return false;
 977         }
 978
 979 }