includes/installer/Installer.php

   1 <?php
   2
   3 /**
   4  * This documentation group collects source code files with deployment functionality.
   5  *
   6  * @defgroup Deployment Deployment
   7  */
   8
   9 /**
  10  * Base installer class.
  11  *
  12  * This class provides the base for installation and update functionality
  13  * for both MediaWiki core and extensions.
  14  *
  15  * @ingroup Deployment
  16  * @since 1.17
  17  */
  18 abstract class Installer {
  19
  20         /**
  21          * TODO: make protected?
  22          *
  23          * @var array
  24          */
  25         public $settings;
  26
  27         /**
  28          * Cached DB installer instances, access using getDBInstaller().
  29          *
  30          * @var array
  31          */
  32         protected $dbInstallers = array();
  33
  34         /**
  35          * Minimum memory size in MB.
  36          *
  37          * @var integer
  38          */
  39         protected $minMemorySize = 50;
  40
  41         /**
  42          * Cached Title, used by parse().
  43          *
  44          * @var Title
  45          */
  46         protected $parserTitle;
  47
  48         /**
  49          * Cached ParserOptions, used by parse().
  50          *
  51          * @var ParserOptions
  52          */
  53         protected $parserOptions;
  54
  55         /**
  56          * Known database types. These correspond to the class names <type>Installer,
  57          * and are also MediaWiki database types valid for $wgDBtype.
  58          *
  59          * To add a new type, create a <type>Installer class and a Database<type>
  60          * class, and add a config-type-<type> message to MessagesEn.php.
  61          *
  62          * @var array
  63          */
  64         protected static $dbTypes = array(
  65                 'mysql',
  66                 'postgres',
  67                 'sqlite',
  68                 'oracle'
  69         );
  70
  71         /**
  72          * A list of environment check methods called by doEnvironmentChecks().
  73          * These may output warnings using showMessage(), and/or abort the
  74          * installation process by returning false.
  75          *
  76          * @var array
  77          */
  78         protected $envChecks = array(
  79                 'envLatestVersion',
  80                 'envCheckDB',
  81                 'envCheckRegisterGlobals',
  82                 'envCheckMagicQuotes',
  83                 'envCheckMagicSybase',
  84                 'envCheckMbstring',
  85                 'envCheckZE1',
  86                 'envCheckSafeMode',
  87                 'envCheckXML',
  88                 'envCheckPCRE',
  89                 'envCheckMemory',
  90                 'envCheckCache',
  91                 'envCheckDiff3',
  92                 'envCheckGraphics',
  93                 'envCheckPath',
  94                 'envCheckWriteableDir',
  95                 'envCheckExtension',
  96                 'envCheckShellLocale',
  97                 'envCheckUploadsDirectory',
  98                 'envCheckLibicu'
  99         );
 100
 101         /**
 102          * UI interface for displaying a short message
 103          * The parameters are like parameters to wfMsg().
 104          * The messages will be in wikitext format, which will be converted to an
 105          * output format such as HTML or text before being sent to the user.
 106          */
 107         public abstract function showMessage( $msg /*, ... */ );
 108
 109         /**
 110          * Constructor, always call this from child classes.
 111          */
 112         public function __construct() {
 113                 // Disable the i18n cache and LoadBalancer
 114                 Language::getLocalisationCache()->disableBackend();
 115                 LBFactory::disableBackend();
 116         }
 117
 118         /**
 119          * Get a list of known DB types.
 120          */
 121         public static function getDBTypes() {
 122                 return self::$dbTypes;
 123         }
 124
 125         /**
 126          * Do initial checks of the PHP environment. Set variables according to
 127          * the observed environment.
 128          *
 129          * It's possible that this may be called under the CLI SAPI, not the SAPI
 130          * that the wiki will primarily run under. In that case, the subclass should
 131          * initialise variables such as wgScriptPath, before calling this function.
 132          *
 133          * Under the web subclass, it can already be assumed that PHP 5+ is in use
 134          * and that sessions are working.
 135          *
 136          * @return boolean
 137          */
 138         public function doEnvironmentChecks() {
 139                 $this->showMessage( 'config-env-php', phpversion() );
 140
 141                 $good = true;
 142
 143                 foreach ( $this->envChecks as $check ) {
 144                         $status = $this->$check();
 145                         if ( $status === false ) {
 146                                 $good = false;
 147                         }
 148                 }
 149
 150                 $this->setVar( '_Environment', $good );
 151
 152                 if ( $good ) {
 153                         $this->showMessage( 'config-env-good' );
 154                 } else {
 155                         $this->showMessage( 'config-env-bad' );
 156                 }
 157
 158                 return $good;
 159         }
 160
 161         /**
 162          * Set a MW configuration variable, or internal installer configuration variable.
 163          *
 164          * @param $name String
 165          * @param $value Mixed
 166          */
 167         public function setVar( $name, $value ) {
 168                 $this->settings[$name] = $value;
 169         }
 170
 171         /**
 172          * Get an MW configuration variable, or internal installer configuration variable.
 173          * The defaults come from $GLOBALS (ultimately DefaultSettings.php).
 174          * Installer variables are typically prefixed by an underscore.
 175          *
 176          * @param $name String
 177          * @param $default Mixed
 178          *
 179          * @return mixed
 180          */
 181         public function getVar( $name, $default = null ) {
 182                 if ( !isset( $this->settings[$name] ) ) {
 183                         return $default;
 184                 } else {
 185                         return $this->settings[$name];
 186                 }
 187         }
 188
 189         /**
 190          * Get an instance of DatabaseInstaller for the specified DB type.
 191          *
 192          * @param $type Mixed: DB installer for which is needed, false to use default.
 193          *
 194          * @return DatabaseInstaller
 195          */
 196         public function getDBInstaller( $type = false ) {
 197                 if ( !$type ) {
 198                         $type = $this->getVar( 'wgDBtype' );
 199                 }
 200
 201                 $type = strtolower( $type );
 202
 203                 if ( !isset( $this->dbInstallers[$type] ) ) {
 204                         $class = ucfirst( $type ). 'Installer';
 205                         $this->dbInstallers[$type] = new $class( $this );
 206                 }
 207
 208                 return $this->dbInstallers[$type];
 209         }
 210
 211         /**
 212          * Determine if LocalSettings exists. If it does, return an appropriate
 213          * status for whether we should can upgrade or not.
 214          *
 215          * @return Status
 216          */
 217         public function getLocalSettingsStatus() {
 218                 global $IP;
 219
 220                 $status = Status::newGood();
 221
 222                 wfSuppressWarnings();
 223                 $ls = file_exists( "$IP/LocalSettings.php" );
 224                 wfRestoreWarnings();
 225
 226                 if( $ls ) {
 227                         if( $this->getDBInstaller()->needsUpgrade() ) {
 228                                 $status->warning( 'config-localsettings-upgrade' );
 229                         }
 230                         else {
 231                                 $status->fatal( 'config-localsettings-noupgrade' );
 232                         }
 233                 }
 234
 235                 return $status;
 236         }
 237
 238         /**
 239          * Get a fake password for sending back to the user in HTML.
 240          * This is a security mechanism to avoid compromise of the password in the
 241          * event of session ID compromise.
 242          *
 243          * @param $realPassword String
 244          *
 245          * @return string
 246          */
 247         public function getFakePassword( $realPassword ) {
 248                 return str_repeat( '*', strlen( $realPassword ) );
 249         }
 250
 251         /**
 252          * Set a variable which stores a password, except if the new value is a
 253          * fake password in which case leave it as it is.
 254          *
 255          * @param $name String
 256          * @param $value Mixed
 257          */
 258         public function setPassword( $name, $value ) {
 259                 if ( !preg_match( '/^\*+$/', $value ) ) {
 260                         $this->setVar( $name, $value );
 261                 }
 262         }
 263
 264         /**
 265          * On POSIX systems return the primary group of the webserver we're running under.
 266          * On other systems just returns null.
 267          *
 268          * This is used to advice the user that he should chgrp his config/data/images directory as the
 269          * webserver user before he can install.
 270          *
 271          * Public because SqliteInstaller needs it, and doesn't subclass Installer.
 272          *
 273          * @return mixed
 274          */
 275         public static function maybeGetWebserverPrimaryGroup() {
 276                 if ( !function_exists( 'posix_getegid' ) || !function_exists( 'posix_getpwuid' ) ) {
 277                         # I don't know this, this isn't UNIX.
 278                         return null;
 279                 }
 280
 281                 # posix_getegid() *not* getmygid() because we want the group of the webserver,
 282                 # not whoever owns the current script.
 283                 $gid = posix_getegid();
 284                 $getpwuid = posix_getpwuid( $gid );
 285                 $group = $getpwuid['name'];
 286
 287                 return $group;
 288         }
 289
 290         /**
 291          * Convert wikitext $text to HTML.
 292          *
 293          * This is potentially error prone since many parser features require a complete
 294          * installed MW database. The solution is to just not use those features when you
 295          * write your messages. This appears to work well enough. Basic formatting and
 296          * external links work just fine.
 297          *
 298          * But in case a translator decides to throw in a #ifexist or internal link or
 299          * whatever, this function is guarded to catch attempted DB access and to present
 300          * some fallback text.
 301          *
 302          * @param $text String
 303          * @param $lineStart Boolean
 304          * @return String
 305          */
 306         public function parse( $text, $lineStart = false ) {
 307                 global $wgParser;
 308
 309                 try {
 310                         $out = $wgParser->parse( $text, $this->parserTitle, $this->parserOptions, $lineStart );
 311                         $html = $out->getText();
 312                 } catch ( DBAccessError $e ) {
 313                         $html = '<!--DB access attempted during parse-->  ' . htmlspecialchars( $text );
 314
 315                         if ( !empty( $this->debug ) ) {
 316                                 $html .= "<!--\n" . $e->getTraceAsString() . "\n-->";
 317                         }
 318                 }
 319
 320                 return $html;
 321         }
 322
 323         /**
 324          * TODO: document
 325          *
 326          * @param DatabaseInstaller $installer
 327          *
 328          * @return Status
 329          */
 330         public function installDatabase( DatabaseInstaller &$installer ) {
 331                 if( !$installer ) {
 332                         $type = $this->getVar( 'wgDBtype' );
 333                         $status = Status::newFatal( "config-no-db", $type );
 334                 } else {
 335                         $status = $installer->setupDatabase();
 336                 }
 337
 338                 return $status;
 339         }
 340
 341         /**
 342          * TODO: document
 343          *
 344          * @param DatabaseInstaller $installer
 345          *
 346          * @return Status
 347          */
 348         public function installTables( DatabaseInstaller &$installer ) {
 349                 $status = $installer->createTables();
 350
 351                 if( $status->isOK() ) {
 352                         LBFactory::enableBackend();
 353                 }
 354
 355                 return $status;
 356         }
 357
 358         /**
 359          * TODO: document
 360          *
 361          * @param DatabaseInstaller $installer
 362          *
 363          * @return Status
 364          */
 365         public function installInterwiki( DatabaseInstaller &$installer ) {
 366                 return $installer->populateInterwikiTable();
 367         }
 368
 369         /**
 370          * Exports all wg* variables stored by the installer into global scope.
 371          */
 372         public function exportVars() {
 373                 foreach ( $this->settings as $name => $value ) {
 374                         if ( substr( $name, 0, 2 ) == 'wg' ) {
 375                                 $GLOBALS[$name] = $value;
 376                         }
 377                 }
 378         }
 379
 380         /**
 381          * Check if we're installing the latest version.
 382          */
 383         public function envLatestVersion() {
 384                 global $wgVersion;
 385
 386                 $repository = wfGetRepository();
 387                 $currentVersion = $repository->getLatestCoreVersion();
 388
 389                 $this->setVar( '_ExternalHTTP', true );
 390
 391                 if ( $currentVersion === false ) {
 392                         # For when the request is successful but there's e.g. some silly man in
 393                         # the middle firewall blocking us, e.g. one of those annoying airport ones
 394                         $this->showMessage( 'config-env-latest-can-not-check', $repository->getLocation() );
 395                         return;
 396                 }
 397
 398                 if( version_compare( $wgVersion, $currentVersion, '<' ) ) {
 399                         $this->showMessage( 'config-env-latest-old' );
 400                         // FIXME: this only works for the web installer!
 401                         $this->showHelpBox( 'config-env-latest-help', $wgVersion, $currentVersion );
 402                 } elseif( version_compare( $wgVersion, $currentVersion, '>' ) ) {
 403                         $this->showMessage( 'config-env-latest-new' );
 404                 }
 405
 406                 $this->showMessage( 'config-env-latest-ok' );
 407         }
 408
 409         /**
 410          * Environment check for DB types.
 411          */
 412         public function envCheckDB() {
 413                 global $wgLang;
 414
 415                 $compiledDBs = array();
 416                 $goodNames = array();
 417                 $allNames = array();
 418
 419                 foreach ( self::getDBTypes() as $name ) {
 420                         $db = $this->getDBInstaller( $name );
 421                         $readableName = wfMsg( 'config-type-' . $name );
 422
 423                         if ( $db->isCompiled() ) {
 424                                 $compiledDBs[] = $name;
 425                                 $goodNames[] = $readableName;
 426                         }
 427
 428                         $allNames[] = $readableName;
 429                 }
 430
 431                 $this->setVar( '_CompiledDBs', $compiledDBs );
 432
 433                 if ( !$compiledDBs ) {
 434                         $this->showMessage( 'config-no-db' );
 435                         // FIXME: this only works for the web installer!
 436                         $this->showHelpBox( 'config-no-db-help', $wgLang->commaList( $allNames ) );
 437                         return false;
 438                 }
 439
 440                 $this->showMessage( 'config-have-db', $wgLang->commaList( $goodNames ) );
 441         }
 442
 443         /**
 444          * Environment check for register_globals.
 445          */
 446         public function envCheckRegisterGlobals() {
 447                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 448                         $this->showMessage( 'config-register-globals' );
 449                 }
 450         }
 451
 452         /**
 453          * Environment check for magic_quotes_runtime.
 454          */
 455         public function envCheckMagicQuotes() {
 456                 if( wfIniGetBool( "magic_quotes_runtime" ) ) {
 457                         $this->showMessage( 'config-magic-quotes-runtime' );
 458                         return false;
 459                 }
 460         }
 461
 462         /**
 463          * Environment check for magic_quotes_sybase.
 464          */
 465         public function envCheckMagicSybase() {
 466                 if ( wfIniGetBool( 'magic_quotes_sybase' ) ) {
 467                         $this->showMessage( 'config-magic-quotes-sybase' );
 468                         return false;
 469                 }
 470         }
 471
 472         /**
 473          * Environment check for mbstring.func_overload.
 474          */
 475         public function envCheckMbstring() {
 476                 if ( wfIniGetBool( 'mbstring.func_overload' ) ) {
 477                         $this->showMessage( 'config-mbstring' );
 478                         return false;
 479                 }
 480         }
 481
 482         /**
 483          * Environment check for zend.ze1_compatibility_mode.
 484          */
 485         public function envCheckZE1() {
 486                 if ( wfIniGetBool( 'zend.ze1_compatibility_mode' ) ) {
 487                         $this->showMessage( 'config-ze1' );
 488                         return false;
 489                 }
 490         }
 491
 492         /**
 493          * Environment check for safe_mode.
 494          */
 495         public function envCheckSafeMode() {
 496                 if ( wfIniGetBool( 'safe_mode' ) ) {
 497                         $this->setVar( '_SafeMode', true );
 498                         $this->showMessage( 'config-safe-mode' );
 499                 }
 500         }
 501
 502         /**
 503          * Environment check for the XML module.
 504          */
 505         public function envCheckXML() {
 506                 if ( !function_exists( "utf8_encode" ) ) {
 507                         $this->showMessage( 'config-xml-bad' );
 508                         return false;
 509                 }
 510                 $this->showMessage( 'config-xml-good' );
 511         }
 512
 513         /**
 514          * Environment check for the PCRE module.
 515          */
 516         public function envCheckPCRE() {
 517                 if ( !function_exists( 'preg_match' ) ) {
 518                         $this->showMessage( 'config-pcre' );
 519                         return false;
 520                 }
 521         }
 522
 523         /**
 524          * Environment check for available memory.
 525          */
 526         public function envCheckMemory() {
 527                 $limit = ini_get( 'memory_limit' );
 528
 529                 if ( !$limit || $limit == -1 ) {
 530                         $this->showMessage( 'config-memory-none' );
 531                         return true;
 532                 }
 533
 534                 $n = intval( $limit );
 535
 536                 if( preg_match( '/^([0-9]+)[Mm]$/', trim( $limit ), $m ) ) {
 537                         $n = intval( $m[1] * ( 1024 * 1024 ) );
 538                 }
 539
 540                 if( $n < $this->minMemorySize * 1024 * 1024 ) {
 541                         $newLimit = "{$this->minMemorySize}M";
 542
 543                         if( ini_set( "memory_limit", $newLimit ) === false ) {
 544                                 $this->showMessage( 'config-memory-bad', $limit );
 545                         } else {
 546                                 $this->showMessage( 'config-memory-raised', $limit, $newLimit );
 547                                 $this->setVar( '_RaiseMemory', true );
 548                         }
 549                 } else {
 550                         $this->showMessage( 'config-memory-ok', $limit );
 551                 }
 552         }
 553
 554         /**
 555          * Environment check for compiled object cache types.
 556          */
 557         public function envCheckCache() {
 558                 $caches = array();
 559
 560                 foreach ( $this->objectCaches as $name => $function ) {
 561                         if ( function_exists( $function ) ) {
 562                                 $caches[$name] = true;
 563                                 $this->showMessage( 'config-' . $name );
 564                         }
 565                 }
 566
 567                 if ( !$caches ) {
 568                         $this->showMessage( 'config-no-cache' );
 569                 }
 570
 571                 $this->setVar( '_Caches', $caches );
 572         }
 573
 574         /**
 575          * Search for GNU diff3.
 576          */
 577         public function envCheckDiff3() {
 578                 $paths = array_merge(
 579                         array(
 580                                 "/usr/bin",
 581                                 "/usr/local/bin",
 582                                 "/opt/csw/bin",
 583                                 "/usr/gnu/bin",
 584                                 "/usr/sfw/bin"
 585                         ),
 586                         explode( PATH_SEPARATOR, getenv( "PATH" ) )
 587                 );
 588
 589                 $names = array( "gdiff3", "diff3", "diff3.exe" );
 590                 $versionInfo = array( '$1 --version 2>&1', 'diff3 (GNU diffutils)' );
 591
 592                 $haveDiff3 = false;
 593
 594                 foreach ( $paths as $path ) {
 595                         $exe = $this->locateExecutable( $path, $names, $versionInfo );
 596
 597                         if ($exe !== false) {
 598                                 $this->setVar( 'wgDiff3', $exe );
 599                                 $haveDiff3 = true;
 600                                 break;
 601                         }
 602                 }
 603
 604                 if ( $haveDiff3 ) {
 605                         $this->showMessage( 'config-diff3-good', $exe );
 606                 } else {
 607                         $this->setVar( 'wgDiff3', false );
 608                         $this->showMessage( 'config-diff3-bad' );
 609                 }
 610         }
 611
 612         /**
 613          * Environment check for ImageMagick and GD.
 614          */
 615         public function envCheckGraphics() {
 616                 $imcheck = array( "/usr/bin", "/opt/csw/bin", "/usr/local/bin", "/sw/bin", "/opt/local/bin" );
 617
 618                 foreach( $imcheck as $dir ) {
 619                         $im = "$dir/convert";
 620
 621                         wfSuppressWarnings();
 622                         $file_exists = file_exists( $im );
 623                         wfRestoreWarnings();
 624
 625                         if( $file_exists ) {
 626                                 $this->showMessage( 'config-imagemagick', $im );
 627                                 $this->setVar( 'wgImageMagickConvertCommand', $im );
 628                                 return true;
 629                         }
 630                 }
 631
 632                 if ( function_exists( 'imagejpeg' ) ) {
 633                         $this->showMessage( 'config-gd' );
 634                         return true;
 635                 }
 636
 637                 $this->showMessage( 'no-scaling' );
 638         }
 639
 640         /**
 641          * Environment check for setting $IP and $wgScriptPath.
 642          */
 643         public function envCheckPath() {
 644                 global $IP;
 645                 $IP = dirname( dirname( dirname( __FILE__ ) ) );
 646
 647                 $this->setVar( 'IP', $IP );
 648                 $this->showMessage( 'config-dir', $IP );
 649
 650                 // PHP_SELF isn't available sometimes, such as when PHP is CGI but
 651                 // cgi.fix_pathinfo is disabled. In that case, fall back to SCRIPT_NAME
 652                 // to get the path to the current script... hopefully it's reliable. SIGH
 653                 if ( !empty( $_SERVER['PHP_SELF'] ) ) {
 654                         $path = $_SERVER['PHP_SELF'];
 655                 } elseif ( !empty( $_SERVER['SCRIPT_NAME'] ) ) {
 656                         $path = $_SERVER['SCRIPT_NAME'];
 657                 } elseif ( $this->getVar( 'wgScriptPath' ) ) {
 658                         // Some kind soul has set it for us already (e.g. debconf)
 659                         return true;
 660                 } else {
 661                         $this->showMessage( 'config-no-uri' );
 662                         return false;
 663                 }
 664
 665                 $uri = preg_replace( '{^(.*)/config.*$}', '$1', $path );
 666                 $this->setVar( 'wgScriptPath', $uri );
 667                 $this->showMessage( 'config-uri', $uri );
 668         }
 669
 670         /**
 671          * Environment check for writable config/ directory.
 672          */
 673         public function envCheckWriteableDir() {
 674                 $ipDir = $this->getVar( 'IP' );
 675                 $configDir = $ipDir . '/config';
 676
 677                 if( !is_writeable( $configDir ) ) {
 678                         $webserverGroup = self::maybeGetWebserverPrimaryGroup();
 679
 680                         if ( $webserverGroup !== null ) {
 681                                 $this->showMessage( 'config-dir-not-writable-group', $ipDir, $webserverGroup );
 682                         } else {
 683                                 $this->showMessage( 'config-dir-not-writable-nogroup', $ipDir, $webserverGroup );
 684                         }
 685
 686                         return false;
 687                 }
 688         }
 689
 690         /**
 691          * Environment check for setting the preferred PHP file extension.
 692          */
 693         public function envCheckExtension() {
 694                 // FIXME: detect this properly
 695                 if ( defined( 'MW_INSTALL_PHP5_EXT' ) ) {
 696                         $ext = 'php5';
 697                 } else {
 698                         $ext = 'php';
 699                 }
 700
 701                 $this->setVar( 'wgScriptExtension', ".$ext" );
 702                 $this->showMessage( 'config-file-extension', $ext );
 703         }
 704
 705         /**
 706          * TODO: document
 707          */
 708         public function envCheckShellLocale() {
 709                 # Give up now if we're in safe mode or open_basedir.
 710                 # It's theoretically possible but tricky to work with.
 711                 if ( wfIniGetBool( "safe_mode" ) || ini_get( 'open_basedir' ) || !function_exists( 'exec' ) ) {
 712                         return true;
 713                 }
 714
 715                 $os = php_uname( 's' );
 716                 $supported = array( 'Linux', 'SunOS', 'HP-UX' ); # Tested these
 717
 718                 if ( !in_array( $os, $supported ) ) {
 719                         return true;
 720                 }
 721
 722                 # Get a list of available locales.
 723                 $lines = $ret = false;
 724                 exec( '/usr/bin/locale -a', $lines, $ret );
 725
 726                 if ( $ret ) {
 727                         return true;
 728                 }
 729
 730                 $lines = wfArrayMap( 'trim', $lines );
 731                 $candidatesByLocale = array();
 732                 $candidatesByLang = array();
 733
 734                 foreach ( $lines as $line ) {
 735                         if ( $line === '' ) {
 736                                 continue;
 737                         }
 738
 739                         if ( !preg_match( '/^([a-zA-Z]+)(_[a-zA-Z]+|)\.(utf8|UTF-8)(@[a-zA-Z_]*|)$/i', $line, $m ) ) {
 740                                 continue;
 741                         }
 742
 743                         list( $all, $lang, $territory, $charset, $modifier ) = $m;
 744
 745                         $candidatesByLocale[$m[0]] = $m;
 746                         $candidatesByLang[$lang][] = $m;
 747                 }
 748
 749                 # Try the current value of LANG.
 750                 if ( isset( $candidatesByLocale[ getenv( 'LANG' ) ] ) ) {
 751                         $this->setVar( 'wgShellLocale', getenv( 'LANG' ) );
 752                         $this->showMessage( 'config-shell-locale', getenv( 'LANG' ) );
 753                         return true;
 754                 }
 755
 756                 # Try the most common ones.
 757                 $commonLocales = array( 'en_US.UTF-8', 'en_US.utf8', 'de_DE.UTF-8', 'de_DE.utf8' );
 758                 foreach ( $commonLocales as $commonLocale ) {
 759                         if ( isset( $candidatesByLocale[$commonLocale] ) ) {
 760                                 $this->setVar( 'wgShellLocale', $commonLocale );
 761                                 $this->showMessage( 'config-shell-locale', $commonLocale );
 762                                 return true;
 763                         }
 764                 }
 765
 766                 # Is there an available locale in the Wiki's language?
 767                 $wikiLang = $this->getVar( 'wgLanguageCode' );
 768
 769                 if ( isset( $candidatesByLang[$wikiLang] ) ) {
 770                         $m = reset( $candidatesByLang[$wikiLang] );
 771                         $this->setVar( 'wgShellLocale', $m[0] );
 772                         $this->showMessage( 'config-shell-locale', $m[0] );
 773                         return true;
 774                 }
 775
 776                 # Are there any at all?
 777                 if ( count( $candidatesByLocale ) ) {
 778                         $m = reset( $candidatesByLocale );
 779                         $this->setVar( 'wgShellLocale', $m[0] );
 780                         $this->showMessage( 'config-shell-locale', $m[0] );
 781                         return true;
 782                 }
 783
 784                 # Give up.
 785                 return true;
 786         }
 787
 788         /**
 789          * TODO: document
 790          */
 791         public function envCheckUploadsDirectory() {
 792                 global $IP, $wgServer;
 793
 794                 $dir = $IP . '/images/';
 795                 $url = $wgServer . $this->getVar( 'wgScriptPath' ) . '/images/';
 796                 $safe = !$this->dirIsExecutable( $dir, $url );
 797
 798                 if ( $safe ) {
 799                         $this->showMessage( 'config-uploads-safe' );
 800                 } else {
 801                         $this->showMessage( 'config-uploads-not-safe', $dir );
 802                 }
 803         }
 804
 805         /**
 806          * Convert a hex string representing a Unicode code point to that code point.
 807          * @param string $c
 808          * @return string
 809          */
 810         protected function unicodeChar( $c ) {
 811                 $c = hexdec($c);
 812                 if ($c <= 0x7F) {
 813                         return chr($c);
 814                 } else if ($c <= 0x7FF) {
 815                         return chr(0xC0 | $c >> 6) . chr(0x80 | $c & 0x3F);
 816                 } else if ($c <= 0xFFFF) {
 817                         return chr(0xE0 | $c >> 12) . chr(0x80 | $c >> 6 & 0x3F)
 818                                 . chr(0x80 | $c & 0x3F);
 819                 } else if ($c <= 0x10FFFF) {
 820                         return chr(0xF0 | $c >> 18) . chr(0x80 | $c >> 12 & 0x3F)
 821                                 . chr(0x80 | $c >> 6 & 0x3F)
 822                                 . chr(0x80 | $c & 0x3F);
 823                 } else {
 824                         return false;
 825                 }
 826         }
 827
 828
 829         /**
 830          * Check the libicu version
 831          */
 832         public function envCheckLibicu() {
 833                 $utf8 = function_exists( 'utf8_normalize' );
 834                 $intl = function_exists( 'normalizer_normalize' );
 835
 836                 /**
 837                  * This needs to be updated something that the latest libicu
 838                  * will properly normalize.  This normalization was found at
 839                  * http://www.unicode.org/versions/Unicode5.2.0/#Character_Additions
 840                  * Note that we use the hex representation to create the code
 841                  * points in order to avoid any Unicode-destroying during transit.
 842                  */
 843                 $not_normal_c = $this->unicodeChar("FA6C");
 844                 $normal_c = $this->unicodeChar("242EE");
 845
 846                 $useNormalizer = 'php';
 847                 $needsUpdate = false;
 848
 849                 /**
 850                  * We're going to prefer the pecl extension here unless
 851                  * utf8_normalize is more up to date.
 852                  */
 853                 if( $utf8 ) {
 854                         $useNormalizer = 'utf8';
 855                         $utf8 = utf8_normalize( $not_normal_c, UNORM_NFC );
 856                         if ( $utf8 !== $normal_c ) $needsUpdate = true;
 857                 }
 858                 if( $intl ) {
 859                         $useNormalizer = 'intl';
 860                         $intl = normalizer_normalize( $not_normal_c, Normalizer::FORM_C );
 861                         if ( $intl !== $normal_c ) $needsUpdate = true;
 862                 }
 863
 864                 // Uses messages 'config-unicode-using-php', 'config-unicode-using-utf8', 'config-unicode-using-intl'
 865                 $this->showMessage( 'config-unicode-using-' . $useNormalizer );
 866                 if( $useNormalizer === 'php' ) {
 867                         $this->showMessage( 'config-unicode-pure-php-warning' );
 868                 } elseif( $needsUpdate ) {
 869                         $this->showMessage( 'config-unicode-update-warning' );
 870                 }
 871         }
 872
 873
 874         /**
 875          * Search a path for any of the given executable names. Returns the
 876          * executable name if found. Also checks the version string returned
 877          * by each executable.
 878          *
 879          * Used only by environment checks.
 880          *
 881          * @param $path String: path to search
 882          * @param $names Array of executable names
 883          * @param $versionInfo Boolean false or array with two members:
 884          *               0 => Command to run for version check, with $1 for the path
 885          *               1 => String to compare the output with
 886          *
 887          * If $versionInfo is not false, only executables with a version
 888          * matching $versionInfo[1] will be returned.
 889          */
 890         protected function locateExecutable( $path, $names, $versionInfo = false ) {
 891                 if ( !is_array( $names ) ) {
 892                         $names = array( $names );
 893                 }
 894
 895                 foreach ( $names as $name ) {
 896                         $command = "$path/$name";
 897
 898                         wfSuppressWarnings();
 899                         $file_exists = file_exists( $command );
 900                         wfRestoreWarnings();
 901
 902                         if ( $file_exists ) {
 903                                 if ( !$versionInfo ) {
 904                                         return $command;
 905                                 }
 906
 907                                 $file = str_replace( '$1', $command, $versionInfo[0] );
 908
 909                                 # Should maybe be wfShellExec( $file), but runs into a ulimit, see
 910                                 # http://www.mediawiki.org/w/index.php?title=New-installer_issues&diff=prev&oldid=335456
 911                                 if ( strstr( `$file`, $versionInfo[1]) !== false ) {
 912                                         return $command;
 913                                 }
 914                         }
 915                 }
 916
 917                 return false;
 918         }
 919
 920         /**
 921          * Checks if scripts located in the given directory can be executed via the given URL.
 922          *
 923          * Used only by environment checks.
 924          */
 925         public function dirIsExecutable( $dir, $url ) {
 926                 $scriptTypes = array(
 927                         'php' => array(
 928                                 "<?php echo 'ex' . 'ec';",
 929                                 "#!/var/env php5\n<?php echo 'ex' . 'ec';",
 930                         ),
 931                 );
 932
 933                 // it would be good to check other popular languages here, but it'll be slow.
 934
 935                 wfSuppressWarnings();
 936
 937                 foreach ( $scriptTypes as $ext => $contents ) {
 938                         foreach ( $contents as $source ) {
 939                                 $file = 'exectest.' . $ext;
 940
 941                                 if ( !file_put_contents( $dir . $file, $source ) ) {
 942                                         break;
 943                                 }
 944
 945                                 $text = Http::get( $url . $file );
 946                                 unlink( $dir . $file );
 947
 948                                 if ( $text == 'exec' ) {
 949                                         wfRestoreWarnings();
 950                                         return $ext;
 951                                 }
 952                         }
 953                 }
 954
 955                 wfRestoreWarnings();
 956
 957                 return false;
 958         }
 959
 960 }