includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere
   4  * @file
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die( "This file is part of MediaWiki, it is not a valid entry point" );
   9 }
  10
  11 require_once dirname( __FILE__ ) . '/normal/UtfNormalUtil.php';
  12
  13 // Hide compatibility functions from Doxygen
  14 /// @cond
  15
  16 /**
  17  * Compatibility functions
  18  *
  19  * We support PHP 5.1.x and up.
  20  * Re-implementations of newer functions or functions in non-standard
  21  * PHP extensions may be included here.
  22  */
  23
  24 # iconv support is not in the default configuration and so may not be present.
  25 # Assume will only ever use utf-8 and iso-8859-1.
  26 # This will *not* work in all circumstances.
  27 function fallback_iconv( $from, $to, $string ) {
  28         if ( substr( $to, -8 ) == '//IGNORE' ) {
  29                 $to = substr( $to, 0, strlen( $to ) - 8 );
  30         }
  31         if( strcasecmp( $from, $to ) == 0 ) {
  32                 return $string;
  33         }
  34         if( strcasecmp( $from, 'utf-8' ) == 0 ) {
  35                 return utf8_decode( $string );
  36         }
  37         if( strcasecmp( $to, 'utf-8' ) == 0 ) {
  38                 return utf8_encode( $string );
  39         }
  40         return $string;
  41 }
  42
  43 if( !function_exists( 'iconv' ) ) {
  44         function iconv( $from, $to, $string ) {
  45                 return fallback_iconv( $from, $to, $string )
  46         }
  47 }
  48
  49
  50
  51
  52 /**
  53  * Fallback implementation for mb_substr, hardcoded to UTF-8.
  54  * Attempts to be at least _moderately_ efficient; best optimized
  55  * for relatively small offset and count values -- about 5x slower
  56  * than native mb_string in my testing.
  57  *
  58  * Larger offsets are still fairly efficient for Latin text, but
  59  * can be up to 100x slower than native if the text is heavily
  60  * multibyte and we have to slog through a few hundred kb.
  61  */
  62 function fallback_mb_substr( $str, $start, $count='end' ) {
  63         if( $start != 0 ) {
  64                 $split = fallback_mb_substr_split_unicode( $str, intval( $start ) );
  65                 $str = substr( $str, $split );
  66         }
  67
  68         if( $count !== 'end' ) {
  69                 $split = fallback_mb_substr_split_unicode( $str, intval( $count ) );
  70                 $str = substr( $str, 0, $split );
  71         }
  72
  73         return $str;
  74 }
  75
  76 function fallback_mb_substr_split_unicode( $str, $splitPos ) {
  77         if( $splitPos == 0 ) {
  78                 return 0;
  79         }
  80
  81         $byteLen = strlen( $str );
  82
  83         if( $splitPos > 0 ) {
  84                 if( $splitPos > 256 ) {
  85                         // Optimize large string offsets by skipping ahead N bytes.
  86                         // This will cut out most of our slow time on Latin-based text,
  87                         // and 1/2 to 1/3 on East European and Asian scripts.
  88                         $bytePos = $splitPos;
  89                         while ( $bytePos < $byteLen && $str{$bytePos} >= "\x80" && $str{$bytePos} < "\xc0" ) {
  90                                 ++$bytePos;
  91                         }
  92                         $charPos = mb_strlen( substr( $str, 0, $bytePos ) );
  93                 } else {
  94                         $charPos = 0;
  95                         $bytePos = 0;
  96                 }
  97
  98                 while( $charPos++ < $splitPos ) {
  99                         ++$bytePos;
 100                         // Move past any tail bytes
 101                         while ( $bytePos < $byteLen && $str{$bytePos} >= "\x80" && $str{$bytePos} < "\xc0" ) {
 102                                 ++$bytePos;
 103                         }
 104                 }
 105         } else {
 106                 $splitPosX = $splitPos + 1;
 107                 $charPos = 0; // relative to end of string; we don't care about the actual char position here
 108                 $bytePos = $byteLen;
 109                 while( $bytePos > 0 && $charPos-- >= $splitPosX ) {
 110                         --$bytePos;
 111                         // Move past any tail bytes
 112                         while ( $bytePos > 0 && $str{$bytePos} >= "\x80" && $str{$bytePos} < "\xc0" ) {
 113                                 --$bytePos;
 114                         }
 115                 }
 116         }
 117
 118         return $bytePos;
 119 }
 120
 121 if ( !function_exists( 'mb_substr' ) ) {
 122         function mb_substr( $str, $start, $count='end' ) {
 123                 return fallback_mb_substr( $str, $start, $count )
 124         }
 125
 126         function mb_substr_split_unicode( $str, $splitPos ) {
 127                 return fallback_mb_substr_split_unicode( $str, $splitPos );
 128         }
 129 }
 130
 131
 132
 133 /**
 134  * Fallback implementation of mb_strlen, hardcoded to UTF-8.
 135  * @param string $str
 136  * @param string $enc optional encoding; ignored
 137  * @return int
 138  */
 139 function fallback_mb_strlen( $str, $enc = '' ) {
 140         $counts = count_chars( $str );
 141         $total = 0;
 142
 143         // Count ASCII bytes
 144         for( $i = 0; $i < 0x80; $i++ ) {
 145                 $total += $counts[$i];
 146         }
 147
 148         // Count multibyte sequence heads
 149         for( $i = 0xc0; $i < 0xff; $i++ ) {
 150                 $total += $counts[$i];
 151         }
 152         return $total;
 153 }
 154
 155 if ( !function_exists( 'mb_strlen' ) ) {
 156         function mb_strlen( $str, $enc = '' ) {
 157                 return fallback_mb_strlen( $str, $enc );
 158         }
 159 }
 160
 161
 162
 163 /**
 164  * Fallback implementation of mb_strpos, hardcoded to UTF-8.
 165  * @param $haystack String
 166  * @param $needle String
 167  * @param $offset String: optional start position
 168  * @param $encoding String: optional encoding; ignored
 169  * @return int
 170  */
 171 function fallback_mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
 172         $needle = preg_quote( $needle, '/' );
 173
 174         $ar = array();
 175         preg_match( '/' . $needle . '/u', $haystack, $ar, PREG_OFFSET_CAPTURE, $offset );
 176
 177         if( isset( $ar[0][1] ) ) {
 178                 return $ar[0][1];
 179         } else {
 180                 return false;
 181         }
 182 }
 183
 184 if( !function_exists( 'mb_strpos' ) ) {
 185
 186         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
 187                 return fallback_mb_strpos( $haystack, $needle, $offset, $encoding );
 188         }
 189
 190 }
 191
 192
 193
 194 /**
 195  * Fallback implementation of mb_strrpos, hardcoded to UTF-8.
 196  * @param $haystack String
 197  * @param $needle String
 198  * @param $offset String: optional start position
 199  * @param $encoding String: optional encoding; ignored
 200  * @return int
 201  */
 202 function fallback_mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
 203         $needle = preg_quote( $needle, '/' );
 204
 205         $ar = array();
 206         preg_match_all( '/' . $needle . '/u', $haystack, $ar, PREG_OFFSET_CAPTURE, $offset );
 207
 208         if( isset( $ar[0] ) && count( $ar[0] ) > 0 &&
 209                 isset( $ar[0][count( $ar[0] ) - 1][1] ) ) {
 210                 return $ar[0][count( $ar[0] ) - 1][1];
 211         } else {
 212                 return false;
 213         }
 214 }
 215
 216 if( !function_exists( 'mb_strrpos' ) ) {
 217         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
 218                 return fallback_mb_strrpos( $haystack, $needle, $offset, $encoding );
 219         }
 220 }
 221
 222
 223 // Support for Wietse Venema's taint feature
 224 if ( !function_exists( 'istainted' ) ) {
 225         function istainted( $var ) {
 226                 return 0;
 227         }
 228         function taint( $var, $level = 0 ) {}
 229         function untaint( $var, $level = 0 ) {}
 230         define( 'TC_HTML', 1 );
 231         define( 'TC_SHELL', 1 );
 232         define( 'TC_MYSQL', 1 );
 233         define( 'TC_PCRE', 1 );
 234         define( 'TC_SELF', 1 );
 235 }
 236 /// @endcond
 237
 238
 239
 240 /**
 241  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 242  */
 243 function wfArrayDiff2( $a, $b ) {
 244         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 245 }
 246 function wfArrayDiff2_cmp( $a, $b ) {
 247         if ( !is_array( $a ) ) {
 248                 return strcmp( $a, $b );
 249         } elseif ( count( $a ) !== count( $b ) ) {
 250                 return count( $a ) < count( $b ) ? -1 : 1;
 251         } else {
 252                 reset( $a );
 253                 reset( $b );
 254                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 255                         $cmp = strcmp( $valueA, $valueB );
 256                         if ( $cmp !== 0 ) {
 257                                 return $cmp;
 258                         }
 259                 }
 260                 return 0;
 261         }
 262 }
 263
 264 /**
 265  * Get a random decimal value between 0 and 1, in a way
 266  * not likely to give duplicate values for any realistic
 267  * number of articles.
 268  *
 269  * @return string
 270  */
 271 function wfRandom() {
 272         # The maximum random value is "only" 2^31-1, so get two random
 273         # values to reduce the chance of dupes
 274         $max = mt_getrandmax() + 1;
 275         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 276                 / $max / $max, 12, '.', '' );
 277         return $rand;
 278 }
 279
 280 /**
 281  * We want some things to be included as literal characters in our title URLs
 282  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 283  * all of the following should be safe:
 284  *
 285  * ;:@&=$-_.+!*'(),
 286  *
 287  * But + is not safe because it's used to indicate a space; &= are only safe in
 288  * paths and not in queries (and we don't distinguish here); ' seems kind of
 289  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 290  * is reserved, we don't care.  So the list we unescape is:
 291  *
 292  * ;:@$!*(),/
 293  *
 294  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 295  * so no fancy : for IIS7.
 296  *
 297  * %2F in the page titles seems to fatally break for some reason.
 298  *
 299  * @param $s String:
 300  * @return string
 301 */
 302 function wfUrlencode( $s ) {
 303         static $needle;
 304         if ( is_null( $needle ) ) {
 305                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 306                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 307                         $needle[] = '%3A';
 308                 }
 309         }
 310
 311         $s = urlencode( $s );
 312         $s = str_ireplace(
 313                 $needle,
 314                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 315                 $s
 316         );
 317
 318         return $s;
 319 }
 320
 321 /**
 322  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 323  * In normal operation this is a NOP.
 324  *
 325  * Controlling globals:
 326  * $wgDebugLogFile - points to the log file
 327  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 328  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 329  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 330  *
 331  * @param $text String
 332  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 333  */
 334 function wfDebug( $text, $logonly = false ) {
 335         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 336         global $wgDebugLogPrefix, $wgShowDebug;
 337
 338         static $cache = array(); // Cache of unoutputted messages
 339         $text = wfDebugTimer() . $text;
 340
 341         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 342         if ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' && !$wgDebugRawPage ) {
 343                 return;
 344         }
 345
 346         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 347                 $cache[] = $text;
 348
 349                 if ( isset( $wgOut ) && StubObject::isRealObject( $wgOut ) ) {
 350                         // add the message and any cached messages to the output
 351                         array_map( array( $wgOut, 'debug' ), $cache );
 352                         $cache = array();
 353                 }
 354         }
 355         if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 356                 # Strip unprintables; they can switch terminal modes when binary data
 357                 # gets dumped, which is pretty annoying.
 358                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 359                 $text = $wgDebugLogPrefix . $text;
 360                 wfErrorLog( $text, $wgDebugLogFile );
 361         }
 362 }
 363
 364 function wfDebugTimer() {
 365         global $wgDebugTimestamps;
 366         if ( !$wgDebugTimestamps ) {
 367                 return '';
 368         }
 369         static $start = null;
 370
 371         if ( $start === null ) {
 372                 $start = microtime( true );
 373                 $prefix = "\n$start";
 374         } else {
 375                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 376         }
 377
 378         return $prefix . '  ';
 379 }
 380
 381 /**
 382  * Send a line giving PHP memory usage.
 383  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 384  */
 385 function wfDebugMem( $exact = false ) {
 386         $mem = memory_get_usage();
 387         if( !$exact ) {
 388                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 389         } else {
 390                 $mem .= ' bytes';
 391         }
 392         wfDebug( "Memory usage: $mem\n" );
 393 }
 394
 395 /**
 396  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 397  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 398  *
 399  * @param $logGroup String
 400  * @param $text String
 401  * @param $public Bool: whether to log the event in the public log if no private
 402  *                     log file is specified, (default true)
 403  */
 404 function wfDebugLog( $logGroup, $text, $public = true ) {
 405         global $wgDebugLogGroups, $wgShowHostnames;
 406         $text = trim( $text ) . "\n";
 407         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 408                 $time = wfTimestamp( TS_DB );
 409                 $wiki = wfWikiID();
 410                 if ( $wgShowHostnames ) {
 411                         $host = wfHostname();
 412                 } else {
 413                         $host = '';
 414                 }
 415                 wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 416         } elseif ( $public === true ) {
 417                 wfDebug( $text, true );
 418         }
 419 }
 420
 421 /**
 422  * Log for database errors
 423  * @param $text String: database error message.
 424  */
 425 function wfLogDBError( $text ) {
 426         global $wgDBerrorLog, $wgDBname;
 427         if ( $wgDBerrorLog ) {
 428                 $host = trim(`hostname`);
 429                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 430                 wfErrorLog( $text, $wgDBerrorLog );
 431         }
 432 }
 433
 434 /**
 435  * Log to a file without getting "file size exceeded" signals.
 436  *
 437  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 438  * send lines to the specified port, prefixed by the specified prefix and a space.
 439  */
 440 function wfErrorLog( $text, $file ) {
 441         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 442                 # Needs the sockets extension
 443                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 444                         // IPv6 bracketed host
 445                         $host = $m[2];
 446                         $port = intval( $m[3] );
 447                         $prefix = isset( $m[4] ) ? $m[4] : false;
 448                         $domain = AF_INET6;
 449                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 450                         $host = $m[2];
 451                         if ( !IP::isIPv4( $host ) ) {
 452                                 $host = gethostbyname( $host );
 453                         }
 454                         $port = intval( $m[3] );
 455                         $prefix = isset( $m[4] ) ? $m[4] : false;
 456                         $domain = AF_INET;
 457                 } else {
 458                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 459                 }
 460                 // Clean it up for the multiplexer
 461                 if ( strval( $prefix ) !== '' ) {
 462                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 463                         if ( substr( $text, -1 ) != "\n" ) {
 464                                 $text .= "\n";
 465                         }
 466                 }
 467
 468                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 469                 if ( !$sock ) {
 470                         return;
 471                 }
 472                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 473                 socket_close( $sock );
 474         } else {
 475                 wfSuppressWarnings();
 476                 $exists = file_exists( $file );
 477                 $size = $exists ? filesize( $file ) : false;
 478                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 479                         error_log( $text, 3, $file );
 480                 }
 481                 wfRestoreWarnings();
 482         }
 483 }
 484
 485 /**
 486  * @todo document
 487  */
 488 function wfLogProfilingData() {
 489         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 490         global $wgProfiler, $wgProfileLimit, $wgUser;
 491         # Profiling must actually be enabled...
 492         if( is_null( $wgProfiler ) ) {
 493                 return;
 494         }
 495         # Get total page request time
 496         $now = wfTime();
 497         $elapsed = $now - $wgRequestTime;
 498         # Only show pages that longer than $wgProfileLimit time (default is 0)
 499         if( $elapsed <= $wgProfileLimit ) {
 500                 return;
 501         }
 502         $prof = wfGetProfilingOutput( $wgRequestTime, $elapsed );
 503         $forward = '';
 504         if( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 505                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 506         }
 507         if( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 508                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 509         }
 510         if( !empty( $_SERVER['HTTP_FROM'] ) ) {
 511                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 512         }
 513         if( $forward ) {
 514                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 515         }
 516         // Don't unstub $wgUser at this late stage just for statistics purposes
 517         // FIXME: We can detect some anons even if it is not loaded. See User::getId()
 518         if( $wgUser->mDataLoaded && $wgUser->isAnon() ) {
 519                 $forward .= ' anon';
 520         }
 521         $log = sprintf( "%s\t%04.3f\t%s\n",
 522                 gmdate( 'YmdHis' ), $elapsed,
 523                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 524         if ( $wgDebugLogFile != '' && ( $wgRequest->getVal( 'action' ) != 'raw' || $wgDebugRawPage ) ) {
 525                 wfErrorLog( $log . $prof, $wgDebugLogFile );
 526         }
 527 }
 528
 529 /**
 530  * Check if the wiki read-only lock file is present. This can be used to lock
 531  * off editing functions, but doesn't guarantee that the database will not be
 532  * modified.
 533  * @return bool
 534  */
 535 function wfReadOnly() {
 536         global $wgReadOnlyFile, $wgReadOnly;
 537
 538         if ( !is_null( $wgReadOnly ) ) {
 539                 return (bool)$wgReadOnly;
 540         }
 541         if ( $wgReadOnlyFile == '' ) {
 542                 return false;
 543         }
 544         // Set $wgReadOnly for faster access next time
 545         if ( is_file( $wgReadOnlyFile ) ) {
 546                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 547         } else {
 548                 $wgReadOnly = false;
 549         }
 550         return (bool)$wgReadOnly;
 551 }
 552
 553 function wfReadOnlyReason() {
 554         global $wgReadOnly;
 555         wfReadOnly();
 556         return $wgReadOnly;
 557 }
 558
 559 /**
 560  * Return a Language object from $langcode
 561  * @param $langcode Mixed: either:
 562  *                  - a Language object
 563  *                  - code of the language to get the message for, if it is
 564  *                    a valid code create a language for that language, if
 565  *                    it is a string but not a valid code then make a basic
 566  *                    language object
 567  *                  - a boolean: if it's false then use the current users
 568  *                    language (as a fallback for the old parameter
 569  *                    functionality), or if it is true then use the wikis
 570  * @return Language object
 571  */
 572 function wfGetLangObj( $langcode = false ) {
 573         # Identify which language to get or create a language object for.
 574         # Using is_object here due to Stub objects.
 575         if( is_object( $langcode ) ) {
 576                 # Great, we already have the object (hopefully)!
 577                 return $langcode;
 578         }
 579
 580         global $wgContLang, $wgLanguageCode;
 581         if( $langcode === true || $langcode === $wgLanguageCode ) {
 582                 # $langcode is the language code of the wikis content language object.
 583                 # or it is a boolean and value is true
 584                 return $wgContLang;
 585         }
 586
 587         global $wgLang;
 588         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 589                 # $langcode is the language code of user language object.
 590                 # or it was a boolean and value is false
 591                 return $wgLang;
 592         }
 593
 594         $validCodes = array_keys( Language::getLanguageNames() );
 595         if( in_array( $langcode, $validCodes ) ) {
 596                 # $langcode corresponds to a valid language.
 597                 return Language::factory( $langcode );
 598         }
 599
 600         # $langcode is a string, but not a valid language code; use content language.
 601         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 602         return $wgContLang;
 603 }
 604
 605 /**
 606  * Use this instead of $wgContLang, when working with user interface.
 607  * User interface is currently hard coded according to wiki content language
 608  * in many ways, especially regarding to text direction. There is lots stuff
 609  * to fix, hence this function to keep the old behaviour unless the global
 610  * $wgBetterDirectionality is enabled (or removed when everything works).
 611  */
 612 function wfUILang() {
 613         global $wgBetterDirectionality;
 614         return wfGetLangObj( !$wgBetterDirectionality );
 615 }
 616
 617 /**
 618  * This is the new function for getting translated interface messages.
 619  * See the Message class for documentation how to use them.
 620  * The intention is that this function replaces all old wfMsg* functions.
 621  * @param $key \string Message key.
 622  * Varargs: normal message parameters.
 623  * @return \type{Message}
 624  * @since 1.17
 625  */
 626 function wfMessage( $key /*...*/) {
 627         $params = func_get_args();
 628         array_shift( $params );
 629         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 630                 $params = $params[0];
 631         }
 632         return new Message( $key, $params );
 633 }
 634
 635 /**
 636  * This function accepts multiple message keys and returns a message instance
 637  * for the first message which is non-empty. If all messages are empty then an
 638  * instance of the first message key is returned.
 639  * Varargs: message keys
 640  * @return \type{Message}
 641  * @since 1.18
 642  */
 643 function wfMessageFallback( /*...*/ ) {
 644         $keys = func_get_args();
 645         $first = $keys[0];
 646         foreach ( $keys as $key ) {
 647                 if ( wfEmptyMsg( $key ) ) {
 648                         continue;
 649                 }
 650                 return wfMessage( $key );
 651         }
 652         return wfMessage( $first );
 653 }
 654
 655 /**
 656  * Get a message from anywhere, for the current user language.
 657  *
 658  * Use wfMsgForContent() instead if the message should NOT
 659  * change depending on the user preferences.
 660  *
 661  * @param $key String: lookup key for the message, usually
 662  *    defined in languages/Language.php
 663  *
 664  * This function also takes extra optional parameters (not
 665  * shown in the function definition), which can be used to
 666  * insert variable text into the predefined message.
 667  */
 668 function wfMsg( $key ) {
 669         $args = func_get_args();
 670         array_shift( $args );
 671         return wfMsgReal( $key, $args, true );
 672 }
 673
 674 /**
 675  * Same as above except doesn't transform the message
 676  */
 677 function wfMsgNoTrans( $key ) {
 678         $args = func_get_args();
 679         array_shift( $args );
 680         return wfMsgReal( $key, $args, true, false, false );
 681 }
 682
 683 /**
 684  * Get a message from anywhere, for the current global language
 685  * set with $wgLanguageCode.
 686  *
 687  * Use this if the message should NOT change dependent on the
 688  * language set in the user's preferences. This is the case for
 689  * most text written into logs, as well as link targets (such as
 690  * the name of the copyright policy page). Link titles, on the
 691  * other hand, should be shown in the UI language.
 692  *
 693  * Note that MediaWiki allows users to change the user interface
 694  * language in their preferences, but a single installation
 695  * typically only contains content in one language.
 696  *
 697  * Be wary of this distinction: If you use wfMsg() where you should
 698  * use wfMsgForContent(), a user of the software may have to
 699  * customize potentially hundreds of messages in
 700  * order to, e.g., fix a link in every possible language.
 701  *
 702  * @param $key String: lookup key for the message, usually
 703  *    defined in languages/Language.php
 704  */
 705 function wfMsgForContent( $key ) {
 706         global $wgForceUIMsgAsContentMsg;
 707         $args = func_get_args();
 708         array_shift( $args );
 709         $forcontent = true;
 710         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 711                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 712         {
 713                 $forcontent = false;
 714         }
 715         return wfMsgReal( $key, $args, true, $forcontent );
 716 }
 717
 718 /**
 719  * Same as above except doesn't transform the message
 720  */
 721 function wfMsgForContentNoTrans( $key ) {
 722         global $wgForceUIMsgAsContentMsg;
 723         $args = func_get_args();
 724         array_shift( $args );
 725         $forcontent = true;
 726         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 727                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 728         {
 729                 $forcontent = false;
 730         }
 731         return wfMsgReal( $key, $args, true, $forcontent, false );
 732 }
 733
 734 /**
 735  * Get a message from the language file, for the UI elements
 736  */
 737 function wfMsgNoDB( $key ) {
 738         $args = func_get_args();
 739         array_shift( $args );
 740         return wfMsgReal( $key, $args, false );
 741 }
 742
 743 /**
 744  * Get a message from the language file, for the content
 745  */
 746 function wfMsgNoDBForContent( $key ) {
 747         global $wgForceUIMsgAsContentMsg;
 748         $args = func_get_args();
 749         array_shift( $args );
 750         $forcontent = true;
 751         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 752                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 753         {
 754                 $forcontent = false;
 755         }
 756         return wfMsgReal( $key, $args, false, $forcontent );
 757 }
 758
 759
 760 /**
 761  * Really get a message
 762  * @param $key String: key to get.
 763  * @param $args
 764  * @param $useDB Boolean
 765  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
 766  * @param $transform Boolean: Whether or not to transform the message.
 767  * @return String: the requested message.
 768  */
 769 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
 770         wfProfileIn( __METHOD__ );
 771         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
 772         $message = wfMsgReplaceArgs( $message, $args );
 773         wfProfileOut( __METHOD__ );
 774         return $message;
 775 }
 776
 777 /**
 778  * This function provides the message source for messages to be edited which are *not* stored in the database.
 779  * @param $key String:
 780  */
 781 function wfMsgWeirdKey( $key ) {
 782         $source = wfMsgGetKey( $key, false, true, false );
 783         if ( wfEmptyMsg( $key, $source ) ) {
 784                 return '';
 785         } else {
 786                 return $source;
 787         }
 788 }
 789
 790 /**
 791  * Fetch a message string value, but don't replace any keys yet.
 792  * @param $key String
 793  * @param $useDB Bool
 794  * @param $langCode String: Code of the language to get the message for, or
 795  *                  behaves as a content language switch if it is a boolean.
 796  * @param $transform Boolean: whether to parse magic words, etc.
 797  * @return string
 798  */
 799 function wfMsgGetKey( $key, $useDB, $langCode = false, $transform = true ) {
 800         global $wgMessageCache;
 801
 802         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
 803
 804         if ( !is_object( $wgMessageCache ) ) {
 805                 throw new MWException( 'Trying to get message before message cache is initialised' );
 806         }
 807
 808         $message = $wgMessageCache->get( $key, $useDB, $langCode );
 809         if( $message === false ) {
 810                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
 811         } elseif ( $transform ) {
 812                 $message = $wgMessageCache->transform( $message );
 813         }
 814         return $message;
 815 }
 816
 817 /**
 818  * Replace message parameter keys on the given formatted output.
 819  *
 820  * @param $message String
 821  * @param $args Array
 822  * @return string
 823  * @private
 824  */
 825 function wfMsgReplaceArgs( $message, $args ) {
 826         # Fix windows line-endings
 827         # Some messages are split with explode("\n", $msg)
 828         $message = str_replace( "\r", '', $message );
 829
 830         // Replace arguments
 831         if ( count( $args ) ) {
 832                 if ( is_array( $args[0] ) ) {
 833                         $args = array_values( $args[0] );
 834                 }
 835                 $replacementKeys = array();
 836                 foreach( $args as $n => $param ) {
 837                         $replacementKeys['$' . ( $n + 1 )] = $param;
 838                 }
 839                 $message = strtr( $message, $replacementKeys );
 840         }
 841
 842         return $message;
 843 }
 844
 845 /**
 846  * Return an HTML-escaped version of a message.
 847  * Parameter replacements, if any, are done *after* the HTML-escaping,
 848  * so parameters may contain HTML (eg links or form controls). Be sure
 849  * to pre-escape them if you really do want plaintext, or just wrap
 850  * the whole thing in htmlspecialchars().
 851  *
 852  * @param $key String
 853  * @param string ... parameters
 854  * @return string
 855  */
 856 function wfMsgHtml( $key ) {
 857         $args = func_get_args();
 858         array_shift( $args );
 859         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key, true ) ), $args );
 860 }
 861
 862 /**
 863  * Return an HTML version of message
 864  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
 865  * so parameters may contain HTML (eg links or form controls). Be sure
 866  * to pre-escape them if you really do want plaintext, or just wrap
 867  * the whole thing in htmlspecialchars().
 868  *
 869  * @param $key String
 870  * @param string ... parameters
 871  * @return string
 872  */
 873 function wfMsgWikiHtml( $key ) {
 874         global $wgOut;
 875         $args = func_get_args();
 876         array_shift( $args );
 877         return wfMsgReplaceArgs( $wgOut->parse( wfMsgGetKey( $key, true ), /* can't be set to false */ true ), $args );
 878 }
 879
 880 /**
 881  * Returns message in the requested format
 882  * @param $key String: key of the message
 883  * @param $options Array: processing rules. Can take the following options:
 884  *   <i>parse</i>: parses wikitext to HTML
 885  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
 886  *       p's added by parser or tidy
 887  *   <i>escape</i>: filters message through htmlspecialchars
 888  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
 889  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
 890  *   <i>parsemag</i>: transform the message using magic phrases
 891  *   <i>content</i>: fetch message for content language instead of interface
 892  * Also can accept a single associative argument, of the form 'language' => 'xx':
 893  *   <i>language</i>: Language object or language code to fetch message for
 894  *       (overriden by <i>content</i>), its behaviour with parse, parseinline
 895  *       and parsemag is undefined.
 896  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
 897  */
 898 function wfMsgExt( $key, $options ) {
 899         global $wgOut;
 900
 901         $args = func_get_args();
 902         array_shift( $args );
 903         array_shift( $args );
 904         $options = (array)$options;
 905
 906         foreach( $options as $arrayKey => $option ) {
 907                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
 908                         # An unknown index, neither numeric nor "language"
 909                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
 910                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
 911                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
 912                 'replaceafter', 'parsemag', 'content' ) ) ) {
 913                         # A numeric index with unknown value
 914                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
 915                 }
 916         }
 917
 918         if( in_array( 'content', $options, true ) ) {
 919                 $forContent = true;
 920                 $langCode = true;
 921         } elseif( array_key_exists( 'language', $options ) ) {
 922                 $forContent = false;
 923                 $langCode = wfGetLangObj( $options['language'] );
 924         } else {
 925                 $forContent = false;
 926                 $langCode = false;
 927         }
 928
 929         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
 930
 931         if( !in_array( 'replaceafter', $options, true ) ) {
 932                 $string = wfMsgReplaceArgs( $string, $args );
 933         }
 934
 935         if( in_array( 'parse', $options, true ) ) {
 936                 $string = $wgOut->parse( $string, true, !$forContent );
 937         } elseif ( in_array( 'parseinline', $options, true ) ) {
 938                 $string = $wgOut->parse( $string, true, !$forContent );
 939                 $m = array();
 940                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 941                         $string = $m[1];
 942                 }
 943         } elseif ( in_array( 'parsemag', $options, true ) ) {
 944                 global $wgMessageCache;
 945                 if ( isset( $wgMessageCache ) ) {
 946                         $string = $wgMessageCache->transform( $string,
 947                                 !$forContent,
 948                                 is_object( $langCode ) ? $langCode : null );
 949                 }
 950         }
 951
 952         if ( in_array( 'escape', $options, true ) ) {
 953                 $string = htmlspecialchars ( $string );
 954         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
 955                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
 956         }
 957
 958         if( in_array( 'replaceafter', $options, true ) ) {
 959                 $string = wfMsgReplaceArgs( $string, $args );
 960         }
 961
 962         return $string;
 963 }
 964
 965
 966 /**
 967  * Just like exit() but makes a note of it.
 968  * Commits open transactions except if the error parameter is set
 969  *
 970  * @deprecated Please return control to the caller or throw an exception. Will
 971  *             be removed in 1.19.
 972  */
 973 function wfAbruptExit( $error = false ) {
 974         static $called = false;
 975         if ( $called ) {
 976                 exit( -1 );
 977         }
 978         $called = true;
 979
 980         wfDeprecated( __FUNCTION__ );
 981         $bt = wfDebugBacktrace();
 982         if( $bt ) {
 983                 for( $i = 0; $i < count( $bt ); $i++ ) {
 984                         $file = isset( $bt[$i]['file'] ) ? $bt[$i]['file'] : 'unknown';
 985                         $line = isset( $bt[$i]['line'] ) ? $bt[$i]['line'] : 'unknown';
 986                         wfDebug( "WARNING: Abrupt exit in $file at line $line\n");
 987                 }
 988         } else {
 989                 wfDebug( "WARNING: Abrupt exit\n" );
 990         }
 991
 992         wfLogProfilingData();
 993
 994         if ( !$error ) {
 995                 wfGetLB()->closeAll();
 996         }
 997         exit( -1 );
 998 }
 999
1000 /**
1001  * @deprecated Please return control the caller or throw an exception. Will
1002  *             be removed in 1.19.
1003  */
1004 function wfErrorExit() {
1005         wfDeprecated( __FUNCTION__ );
1006         wfAbruptExit( true );
1007 }
1008
1009 /**
1010  * Print a simple message and die, returning nonzero to the shell if any.
1011  * Plain die() fails to return nonzero to the shell if you pass a string.
1012  * @param $msg String
1013  */
1014 function wfDie( $msg = '' ) {
1015         echo $msg;
1016         die( 1 );
1017 }
1018
1019 /**
1020  * Throw a debugging exception. This function previously once exited the process,
1021  * but now throws an exception instead, with similar results.
1022  *
1023  * @param $msg String: message shown when dieing.
1024  */
1025 function wfDebugDieBacktrace( $msg = '' ) {
1026         throw new MWException( $msg );
1027 }
1028
1029 /**
1030  * Fetch server name for use in error reporting etc.
1031  * Use real server name if available, so we know which machine
1032  * in a server farm generated the current page.
1033  * @return string
1034  */
1035 function wfHostname() {
1036         static $host;
1037         if ( is_null( $host ) ) {
1038                 if ( function_exists( 'posix_uname' ) ) {
1039                         // This function not present on Windows
1040                         $uname = @posix_uname();
1041                 } else {
1042                         $uname = false;
1043                 }
1044                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1045                         $host = $uname['nodename'];
1046                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1047                         # Windows computer name
1048                         $host = getenv( 'COMPUTERNAME' );
1049                 } else {
1050                         # This may be a virtual server.
1051                         $host = $_SERVER['SERVER_NAME'];
1052                 }
1053         }
1054         return $host;
1055 }
1056
1057 /**
1058  * Returns a HTML comment with the elapsed time since request.
1059  * This method has no side effects.
1060  * @return string
1061  */
1062 function wfReportTime() {
1063         global $wgRequestTime, $wgShowHostnames;
1064
1065         $now = wfTime();
1066         $elapsed = $now - $wgRequestTime;
1067
1068         return $wgShowHostnames
1069                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1070                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1071 }
1072
1073 /**
1074  * Safety wrapper for debug_backtrace().
1075  *
1076  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1077  * murky circumstances, which may be triggered in part by stub objects
1078  * or other fancy talkin'.
1079  *
1080  * Will return an empty array if Zend Optimizer is detected or if
1081  * debug_backtrace is disabled, otherwise the output from
1082  * debug_backtrace() (trimmed).
1083  *
1084  * @return array of backtrace information
1085  */
1086 function wfDebugBacktrace() {
1087         static $disabled = null;
1088
1089         if( extension_loaded( 'Zend Optimizer' ) ) {
1090                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1091                 return array();
1092         }
1093
1094         if ( is_null( $disabled ) ) {
1095                 $disabled = false;
1096                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1097                 $functions = array_map( 'trim', $functions );
1098                 $functions = array_map( 'strtolower', $functions );
1099                 if ( in_array( 'debug_backtrace', $functions ) ) {
1100                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1101                         $disabled = true;
1102                 }
1103         }
1104         if ( $disabled ) {
1105                 return array();
1106         }
1107
1108         return array_slice( debug_backtrace(), 1 );
1109 }
1110
1111 function wfBacktrace() {
1112         global $wgCommandLineMode;
1113
1114         if ( $wgCommandLineMode ) {
1115                 $msg = '';
1116         } else {
1117                 $msg = "<ul>\n";
1118         }
1119         $backtrace = wfDebugBacktrace();
1120         foreach( $backtrace as $call ) {
1121                 if( isset( $call['file'] ) ) {
1122                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1123                         $file = $f[count( $f ) - 1];
1124                 } else {
1125                         $file = '-';
1126                 }
1127                 if( isset( $call['line'] ) ) {
1128                         $line = $call['line'];
1129                 } else {
1130                         $line = '-';
1131                 }
1132                 if ( $wgCommandLineMode ) {
1133                         $msg .= "$file line $line calls ";
1134                 } else {
1135                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1136                 }
1137                 if( !empty( $call['class'] ) ) {
1138                         $msg .= $call['class'] . '::';
1139                 }
1140                 $msg .= $call['function'] . '()';
1141
1142                 if ( $wgCommandLineMode ) {
1143                         $msg .= "\n";
1144                 } else {
1145                         $msg .= "</li>\n";
1146                 }
1147         }
1148         if ( $wgCommandLineMode ) {
1149                 $msg .= "\n";
1150         } else {
1151                 $msg .= "</ul>\n";
1152         }
1153
1154         return $msg;
1155 }
1156
1157
1158 /* Some generic result counters, pulled out of SearchEngine */
1159
1160
1161 /**
1162  * @todo document
1163  */
1164 function wfShowingResults( $offset, $limit ) {
1165         global $wgLang;
1166         return wfMsgExt(
1167                 'showingresults',
1168                 array( 'parseinline' ),
1169                 $wgLang->formatNum( $limit ),
1170                 $wgLang->formatNum( $offset + 1 )
1171         );
1172 }
1173
1174 /**
1175  * @todo document
1176  */
1177 function wfShowingResultsNum( $offset, $limit, $num ) {
1178         global $wgLang;
1179         return wfMsgExt(
1180                 'showingresultsnum',
1181                 array( 'parseinline' ),
1182                 $wgLang->formatNum( $limit ),
1183                 $wgLang->formatNum( $offset + 1 ),
1184                 $wgLang->formatNum( $num )
1185         );
1186 }
1187
1188 /**
1189  * Generate (prev x| next x) (20|50|100...) type links for paging
1190  * @param $offset String
1191  * @param $limit Integer
1192  * @param $link String
1193  * @param $query String: optional URL query parameter string
1194  * @param $atend Bool: optional param for specified if this is the last page
1195  */
1196 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1197         global $wgLang;
1198         $fmtLimit = $wgLang->formatNum( $limit );
1199         // FIXME: Why on earth this needs one message for the text and another one for tooltip??
1200         # Get prev/next link display text
1201         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1202         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1203         # Get prev/next link title text
1204         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1205         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1206         # Fetch the title object
1207         if( is_object( $link ) ) {
1208                 $title =& $link;
1209         } else {
1210                 $title = Title::newFromText( $link );
1211                 if( is_null( $title ) ) {
1212                         return false;
1213                 }
1214         }
1215         # Make 'previous' link
1216         if( 0 != $offset ) {
1217                 $po = $offset - $limit;
1218                 $po = max( $po, 0 );
1219                 $q = "limit={$limit}&offset={$po}";
1220                 if( $query != '' ) {
1221                         $q .= '&' . $query;
1222                 }
1223                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1224         } else {
1225                 $plink = $prev;
1226         }
1227         # Make 'next' link
1228         $no = $offset + $limit;
1229         $q = "limit={$limit}&offset={$no}";
1230         if( $query != '' ) {
1231                 $q .= '&' . $query;
1232         }
1233         if( $atend ) {
1234                 $nlink = $next;
1235         } else {
1236                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1237         }
1238         # Make links to set number of items per page
1239         $nums = $wgLang->pipeList( array(
1240                 wfNumLink( $offset, 20, $title, $query ),
1241                 wfNumLink( $offset, 50, $title, $query ),
1242                 wfNumLink( $offset, 100, $title, $query ),
1243                 wfNumLink( $offset, 250, $title, $query ),
1244                 wfNumLink( $offset, 500, $title, $query )
1245         ) );
1246         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1247 }
1248
1249 /**
1250  * Generate links for (20|50|100...) items-per-page links
1251  * @param $offset String
1252  * @param $limit Integer
1253  * @param $title Title
1254  * @param $query String: optional URL query parameter string
1255  */
1256 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1257         global $wgLang;
1258         if( $query == '' ) {
1259                 $q = '';
1260         } else {
1261                 $q = $query.'&';
1262         }
1263         $q .= "limit={$limit}&offset={$offset}";
1264         $fmtLimit = $wgLang->formatNum( $limit );
1265         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1266         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1267         return $s;
1268 }
1269
1270 /**
1271  * @todo document
1272  * @todo FIXME: we may want to blacklist some broken browsers
1273  *
1274  * @return bool Whereas client accept gzip compression
1275  */
1276 function wfClientAcceptsGzip() {
1277         static $result = null;
1278         if ( $result === null ) {
1279                 $result = false;
1280                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1281                         # FIXME: we may want to blacklist some broken browsers
1282                         $m = array();
1283                         if( preg_match(
1284                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1285                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1286                                 $m )
1287                         )
1288                         {
1289                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1290                                         $result = false;
1291                                         return $result;
1292                                 }
1293                                 wfDebug( " accepts gzip\n" );
1294                                 $result = true;
1295                         }
1296                 }
1297         }
1298         return $result;
1299 }
1300
1301 /**
1302  * Obtain the offset and limit values from the request string;
1303  * used in special pages
1304  *
1305  * @param $deflimit Default limit if none supplied
1306  * @param $optionname Name of a user preference to check against
1307  * @return array
1308  *
1309  */
1310 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1311         global $wgRequest;
1312         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1313 }
1314
1315 /**
1316  * Escapes the given text so that it may be output using addWikiText()
1317  * without any linking, formatting, etc. making its way through. This
1318  * is achieved by substituting certain characters with HTML entities.
1319  * As required by the callers, <nowiki> is not used. It currently does
1320  * not filter out characters which have special meaning only at the
1321  * start of a line, such as "*".
1322  *
1323  * @param $text String: text to be escaped
1324  */
1325 function wfEscapeWikiText( $text ) {
1326         $text = str_replace(
1327                 array( '[',     '|',      ']',     '\'',    'ISBN ',
1328                         'RFC ',     '://',     "\n=",     '{{',           '}}' ),
1329                 array( '&#91;', '&#124;', '&#93;', '&#39;', 'ISBN&#32;',
1330                         'RFC&#32;', '&#58;//', "\n&#61;", '&#123;&#123;', '&#125;&#125;' ),
1331                 htmlspecialchars( $text )
1332         );
1333         return $text;
1334 }
1335
1336 /**
1337  * @todo document
1338  * @return float
1339  */
1340 function wfTime() {
1341         return microtime( true );
1342 }
1343
1344 /**
1345  * Sets dest to source and returns the original value of dest
1346  * If source is NULL, it just returns the value, it doesn't set the variable
1347  * If force is true, it will set the value even if source is NULL
1348  */
1349 function wfSetVar( &$dest, $source, $force = false ) {
1350         $temp = $dest;
1351         if ( !is_null( $source ) || $force ) {
1352                 $dest = $source;
1353         }
1354         return $temp;
1355 }
1356
1357 /**
1358  * As for wfSetVar except setting a bit
1359  */
1360 function wfSetBit( &$dest, $bit, $state = true ) {
1361         $temp = (bool)( $dest & $bit );
1362         if ( !is_null( $state ) ) {
1363                 if ( $state ) {
1364                         $dest |= $bit;
1365                 } else {
1366                         $dest &= ~$bit;
1367                 }
1368         }
1369         return $temp;
1370 }
1371
1372 /**
1373  * This function takes two arrays as input, and returns a CGI-style string, e.g.
1374  * "days=7&limit=100". Options in the first array override options in the second.
1375  * Options set to "" will not be output.
1376  */
1377 function wfArrayToCGI( $array1, $array2 = null ) {
1378         if ( !is_null( $array2 ) ) {
1379                 $array1 = $array1 + $array2;
1380         }
1381
1382         $cgi = '';
1383         foreach ( $array1 as $key => $value ) {
1384                 if ( $value !== '' ) {
1385                         if ( $cgi != '' ) {
1386                                 $cgi .= '&';
1387                         }
1388                         if ( is_array( $value ) ) {
1389                                 $firstTime = true;
1390                                 foreach ( $value as $v ) {
1391                                         $cgi .= ( $firstTime ? '' : '&') .
1392                                                 urlencode( $key . '[]' ) . '=' .
1393                                                 urlencode( $v );
1394                                         $firstTime = false;
1395                                 }
1396                         } else {
1397                                 if ( is_object( $value ) ) {
1398                                         $value = $value->__toString();
1399                                 }
1400                                 $cgi .= urlencode( $key ) . '=' .
1401                                         urlencode( $value );
1402                         }
1403                 }
1404         }
1405         return $cgi;
1406 }
1407
1408 /**
1409  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
1410  * its argument and returns the same string in array form.  This allows compa-
1411  * tibility with legacy functions that accept raw query strings instead of nice
1412  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
1413  * valid query strings, or it will explode.
1414  *
1415  * @param $query String: query string
1416  * @return array Array version of input
1417  */
1418 function wfCgiToArray( $query ) {
1419         if( isset( $query[0] ) && $query[0] == '?' ) {
1420                 $query = substr( $query, 1 );
1421         }
1422         $bits = explode( '&', $query );
1423         $ret = array();
1424         foreach( $bits as $bit ) {
1425                 if( $bit === '' ) {
1426                         continue;
1427                 }
1428                 list( $key, $value ) = explode( '=', $bit );
1429                 $key = urldecode( $key );
1430                 $value = urldecode( $value );
1431                 $ret[$key] = $value;
1432         }
1433         return $ret;
1434 }
1435
1436 /**
1437  * Append a query string to an existing URL, which may or may not already
1438  * have query string parameters already. If so, they will be combined.
1439  *
1440  * @param $url String
1441  * @param $query Mixed: string or associative array
1442  * @return string
1443  */
1444 function wfAppendQuery( $url, $query ) {
1445         if ( is_array( $query ) ) {
1446                 $query = wfArrayToCGI( $query );
1447         }
1448         if( $query != '' ) {
1449                 if( false === strpos( $url, '?' ) ) {
1450                         $url .= '?';
1451                 } else {
1452                         $url .= '&';
1453                 }
1454                 $url .= $query;
1455         }
1456         return $url;
1457 }
1458
1459 /**
1460  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
1461  * and $wgProto are correct.
1462  *
1463  * @todo this won't work with current-path-relative URLs
1464  * like "subdir/foo.html", etc.
1465  *
1466  * @param $url String: either fully-qualified or a local path + query
1467  * @return string Fully-qualified URL
1468  */
1469 function wfExpandUrl( $url ) {
1470         if( substr( $url, 0, 2 ) == '//' ) {
1471                 global $wgProto;
1472                 return $wgProto . ':' . $url;
1473         } elseif( substr( $url, 0, 1 ) == '/' ) {
1474                 global $wgServer;
1475                 return $wgServer . $url;
1476         } else {
1477                 return $url;
1478         }
1479 }
1480
1481 /**
1482  * Windows-compatible version of escapeshellarg()
1483  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1484  * function puts single quotes in regardless of OS.
1485  *
1486  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1487  * earlier distro releases of PHP)
1488  */
1489 function wfEscapeShellArg( ) {
1490         wfInitShellLocale();
1491
1492         $args = func_get_args();
1493         $first = true;
1494         $retVal = '';
1495         foreach ( $args as $arg ) {
1496                 if ( !$first ) {
1497                         $retVal .= ' ';
1498                 } else {
1499                         $first = false;
1500                 }
1501
1502                 if ( wfIsWindows() ) {
1503                         // Escaping for an MSVC-style command line parser and CMD.EXE
1504                         // Refs:
1505                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1506                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1507                         //  * Bug #13518
1508                         //  * CR r63214
1509                         // Double the backslashes before any double quotes. Escape the double quotes.
1510                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1511                         $arg = '';
1512                         $iteration = 0;
1513                         foreach ( $tokens as $token ) {
1514                                 if ( $iteration % 2 == 1 ) {
1515                                         // Delimiter, a double quote preceded by zero or more slashes
1516                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1517                                 } elseif ( $iteration % 4 == 2 ) {
1518                                         // ^ in $token will be outside quotes, need to be escaped
1519                                         $arg .= str_replace( '^', '^^', $token );
1520                                 } else { // $iteration % 4 == 0
1521                                         // ^ in $token will appear inside double quotes, so leave as is
1522                                         $arg .= $token;
1523                                 }
1524                                 $iteration++;
1525                         }
1526                         // Double the backslashes before the end of the string, because
1527                         // we will soon add a quote
1528                         $m = array();
1529                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1530                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1531                         }
1532
1533                         // Add surrounding quotes
1534                         $retVal .= '"' . $arg . '"';
1535                 } else {
1536                         $retVal .= escapeshellarg( $arg );
1537                 }
1538         }
1539         return $retVal;
1540 }
1541
1542 /**
1543  * wfMerge attempts to merge differences between three texts.
1544  * Returns true for a clean merge and false for failure or a conflict.
1545  */
1546 function wfMerge( $old, $mine, $yours, &$result ) {
1547         global $wgDiff3;
1548
1549         # This check may also protect against code injection in
1550         # case of broken installations.
1551         wfSuppressWarnings();
1552         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1553         wfRestoreWarnings();
1554
1555         if( !$haveDiff3 ) {
1556                 wfDebug( "diff3 not found\n" );
1557                 return false;
1558         }
1559
1560         # Make temporary files
1561         $td = wfTempDir();
1562         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1563         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1564         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1565
1566         fwrite( $oldtextFile, $old );
1567         fclose( $oldtextFile );
1568         fwrite( $mytextFile, $mine );
1569         fclose( $mytextFile );
1570         fwrite( $yourtextFile, $yours );
1571         fclose( $yourtextFile );
1572
1573         # Check for a conflict
1574         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1575                 wfEscapeShellArg( $mytextName ) . ' ' .
1576                 wfEscapeShellArg( $oldtextName ) . ' ' .
1577                 wfEscapeShellArg( $yourtextName );
1578         $handle = popen( $cmd, 'r' );
1579
1580         if( fgets( $handle, 1024 ) ) {
1581                 $conflict = true;
1582         } else {
1583                 $conflict = false;
1584         }
1585         pclose( $handle );
1586
1587         # Merge differences
1588         $cmd = $wgDiff3 . ' -a -e --merge ' .
1589                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1590         $handle = popen( $cmd, 'r' );
1591         $result = '';
1592         do {
1593                 $data = fread( $handle, 8192 );
1594                 if ( strlen( $data ) == 0 ) {
1595                         break;
1596                 }
1597                 $result .= $data;
1598         } while ( true );
1599         pclose( $handle );
1600         unlink( $mytextName );
1601         unlink( $oldtextName );
1602         unlink( $yourtextName );
1603
1604         if ( $result === '' && $old !== '' && !$conflict ) {
1605                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1606                 $conflict = true;
1607         }
1608         return !$conflict;
1609 }
1610
1611 /**
1612  * Returns unified plain-text diff of two texts.
1613  * Useful for machine processing of diffs.
1614  * @param $before String: the text before the changes.
1615  * @param $after String: the text after the changes.
1616  * @param $params String: command-line options for the diff command.
1617  * @return String: unified diff of $before and $after
1618  */
1619 function wfDiff( $before, $after, $params = '-u' ) {
1620         if ( $before == $after ) {
1621                 return '';
1622         }
1623
1624         global $wgDiff;
1625         wfSuppressWarnings();
1626         $haveDiff = $wgDiff && file_exists( $wgDiff );
1627         wfRestoreWarnings();
1628
1629         # This check may also protect against code injection in
1630         # case of broken installations.
1631         if( !$haveDiff ) {
1632                 wfDebug( "diff executable not found\n" );
1633                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1634                 $format = new UnifiedDiffFormatter();
1635                 return $format->format( $diffs );
1636         }
1637
1638         # Make temporary files
1639         $td = wfTempDir();
1640         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1641         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1642
1643         fwrite( $oldtextFile, $before );
1644         fclose( $oldtextFile );
1645         fwrite( $newtextFile, $after );
1646         fclose( $newtextFile );
1647
1648         // Get the diff of the two files
1649         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1650
1651         $h = popen( $cmd, 'r' );
1652
1653         $diff = '';
1654
1655         do {
1656                 $data = fread( $h, 8192 );
1657                 if ( strlen( $data ) == 0 ) {
1658                         break;
1659                 }
1660                 $diff .= $data;
1661         } while ( true );
1662
1663         // Clean up
1664         pclose( $h );
1665         unlink( $oldtextName );
1666         unlink( $newtextName );
1667
1668         // Kill the --- and +++ lines. They're not useful.
1669         $diff_lines = explode( "\n", $diff );
1670         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1671                 unset( $diff_lines[0] );
1672         }
1673         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1674                 unset( $diff_lines[1] );
1675         }
1676
1677         $diff = implode( "\n", $diff_lines );
1678
1679         return $diff;
1680 }
1681
1682 /**
1683  * A wrapper around the PHP function var_export().
1684  * Either print it or add it to the regular output ($wgOut).
1685  *
1686  * @param $var A PHP variable to dump.
1687  */
1688 function wfVarDump( $var ) {
1689         global $wgOut;
1690         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1691         if ( headers_sent() || !@is_object( $wgOut ) ) {
1692                 print $s;
1693         } else {
1694                 $wgOut->addHTML( $s );
1695         }
1696 }
1697
1698 /**
1699  * Provide a simple HTTP error.
1700  */
1701 function wfHttpError( $code, $label, $desc ) {
1702         global $wgOut;
1703         $wgOut->disable();
1704         header( "HTTP/1.0 $code $label" );
1705         header( "Status: $code $label" );
1706         $wgOut->sendCacheControl();
1707
1708         header( 'Content-type: text/html; charset=utf-8' );
1709         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1710                 '<html><head><title>' .
1711                 htmlspecialchars( $label ) .
1712                 '</title></head><body><h1>' .
1713                 htmlspecialchars( $label ) .
1714                 '</h1><p>' .
1715                 nl2br( htmlspecialchars( $desc ) ) .
1716                 "</p></body></html>\n";
1717 }
1718
1719 /**
1720  * Clear away any user-level output buffers, discarding contents.
1721  *
1722  * Suitable for 'starting afresh', for instance when streaming
1723  * relatively large amounts of data without buffering, or wanting to
1724  * output image files without ob_gzhandler's compression.
1725  *
1726  * The optional $resetGzipEncoding parameter controls suppression of
1727  * the Content-Encoding header sent by ob_gzhandler; by default it
1728  * is left. See comments for wfClearOutputBuffers() for why it would
1729  * be used.
1730  *
1731  * Note that some PHP configuration options may add output buffer
1732  * layers which cannot be removed; these are left in place.
1733  *
1734  * @param $resetGzipEncoding Bool
1735  */
1736 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1737         if( $resetGzipEncoding ) {
1738                 // Suppress Content-Encoding and Content-Length
1739                 // headers from 1.10+s wfOutputHandler
1740                 global $wgDisableOutputCompression;
1741                 $wgDisableOutputCompression = true;
1742         }
1743         while( $status = ob_get_status() ) {
1744                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1745                         // Probably from zlib.output_compression or other
1746                         // PHP-internal setting which can't be removed.
1747                         //
1748                         // Give up, and hope the result doesn't break
1749                         // output behavior.
1750                         break;
1751                 }
1752                 if( !ob_end_clean() ) {
1753                         // Could not remove output buffer handler; abort now
1754                         // to avoid getting in some kind of infinite loop.
1755                         break;
1756                 }
1757                 if( $resetGzipEncoding ) {
1758                         if( $status['name'] == 'ob_gzhandler' ) {
1759                                 // Reset the 'Content-Encoding' field set by this handler
1760                                 // so we can start fresh.
1761                                 header( 'Content-Encoding:' );
1762                                 break;
1763                         }
1764                 }
1765         }
1766 }
1767
1768 /**
1769  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1770  *
1771  * Clear away output buffers, but keep the Content-Encoding header
1772  * produced by ob_gzhandler, if any.
1773  *
1774  * This should be used for HTTP 304 responses, where you need to
1775  * preserve the Content-Encoding header of the real result, but
1776  * also need to suppress the output of ob_gzhandler to keep to spec
1777  * and avoid breaking Firefox in rare cases where the headers and
1778  * body are broken over two packets.
1779  */
1780 function wfClearOutputBuffers() {
1781         wfResetOutputBuffers( false );
1782 }
1783
1784 /**
1785  * Converts an Accept-* header into an array mapping string values to quality
1786  * factors
1787  */
1788 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1789         # No arg means accept anything (per HTTP spec)
1790         if( !$accept ) {
1791                 return array( $def => 1.0 );
1792         }
1793
1794         $prefs = array();
1795
1796         $parts = explode( ',', $accept );
1797
1798         foreach( $parts as $part ) {
1799                 # FIXME: doesn't deal with params like 'text/html; level=1'
1800                 @list( $value, $qpart ) = explode( ';', trim( $part ) );
1801                 $match = array();
1802                 if( !isset( $qpart ) ) {
1803                         $prefs[$value] = 1.0;
1804                 } elseif( preg_match( '/q\s*=\s*(\d*\.\d+)/', $qpart, $match ) ) {
1805                         $prefs[$value] = floatval( $match[1] );
1806                 }
1807         }
1808
1809         return $prefs;
1810 }
1811
1812 /**
1813  * Checks if a given MIME type matches any of the keys in the given
1814  * array. Basic wildcards are accepted in the array keys.
1815  *
1816  * Returns the matching MIME type (or wildcard) if a match, otherwise
1817  * NULL if no match.
1818  *
1819  * @param $type String
1820  * @param $avail Array
1821  * @return string
1822  * @private
1823  */
1824 function mimeTypeMatch( $type, $avail ) {
1825         if( array_key_exists( $type, $avail ) ) {
1826                 return $type;
1827         } else {
1828                 $parts = explode( '/', $type );
1829                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
1830                         return $parts[0] . '/*';
1831                 } elseif( array_key_exists( '*/*', $avail ) ) {
1832                         return '*/*';
1833                 } else {
1834                         return null;
1835                 }
1836         }
1837 }
1838
1839 /**
1840  * Returns the 'best' match between a client's requested internet media types
1841  * and the server's list of available types. Each list should be an associative
1842  * array of type to preference (preference is a float between 0.0 and 1.0).
1843  * Wildcards in the types are acceptable.
1844  *
1845  * @param $cprefs Array: client's acceptable type list
1846  * @param $sprefs Array: server's offered types
1847  * @return string
1848  *
1849  * @todo FIXME: doesn't handle params like 'text/plain; charset=UTF-8'
1850  * XXX: generalize to negotiate other stuff
1851  */
1852 function wfNegotiateType( $cprefs, $sprefs ) {
1853         $combine = array();
1854
1855         foreach( array_keys($sprefs) as $type ) {
1856                 $parts = explode( '/', $type );
1857                 if( $parts[1] != '*' ) {
1858                         $ckey = mimeTypeMatch( $type, $cprefs );
1859                         if( $ckey ) {
1860                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1861                         }
1862                 }
1863         }
1864
1865         foreach( array_keys( $cprefs ) as $type ) {
1866                 $parts = explode( '/', $type );
1867                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
1868                         $skey = mimeTypeMatch( $type, $sprefs );
1869                         if( $skey ) {
1870                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1871                         }
1872                 }
1873         }
1874
1875         $bestq = 0;
1876         $besttype = null;
1877
1878         foreach( array_keys( $combine ) as $type ) {
1879                 if( $combine[$type] > $bestq ) {
1880                         $besttype = $type;
1881                         $bestq = $combine[$type];
1882                 }
1883         }
1884
1885         return $besttype;
1886 }
1887
1888 /**
1889  * Array lookup
1890  * Returns an array where the values in the first array are replaced by the
1891  * values in the second array with the corresponding keys
1892  *
1893  * @return array
1894  */
1895 function wfArrayLookup( $a, $b ) {
1896         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
1897 }
1898
1899 /**
1900  * Convenience function; returns MediaWiki timestamp for the present time.
1901  * @return string
1902  */
1903 function wfTimestampNow() {
1904         # return NOW
1905         return wfTimestamp( TS_MW, time() );
1906 }
1907
1908 /**
1909  * Reference-counted warning suppression
1910  */
1911 function wfSuppressWarnings( $end = false ) {
1912         static $suppressCount = 0;
1913         static $originalLevel = false;
1914
1915         if ( $end ) {
1916                 if ( $suppressCount ) {
1917                         --$suppressCount;
1918                         if ( !$suppressCount ) {
1919                                 error_reporting( $originalLevel );
1920                         }
1921                 }
1922         } else {
1923                 if ( !$suppressCount ) {
1924                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE ) );
1925                 }
1926                 ++$suppressCount;
1927         }
1928 }
1929
1930 /**
1931  * Restore error level to previous value
1932  */
1933 function wfRestoreWarnings() {
1934         wfSuppressWarnings( true );
1935 }
1936
1937 # Autodetect, convert and provide timestamps of various types
1938
1939 /**
1940  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
1941  */
1942 define( 'TS_UNIX', 0 );
1943
1944 /**
1945  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
1946  */
1947 define( 'TS_MW', 1 );
1948
1949 /**
1950  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
1951  */
1952 define( 'TS_DB', 2 );
1953
1954 /**
1955  * RFC 2822 format, for E-mail and HTTP headers
1956  */
1957 define( 'TS_RFC2822', 3 );
1958
1959 /**
1960  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
1961  *
1962  * This is used by Special:Export
1963  */
1964 define( 'TS_ISO_8601', 4 );
1965
1966 /**
1967  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
1968  *
1969  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
1970  *       DateTime tag and page 36 for the DateTimeOriginal and
1971  *       DateTimeDigitized tags.
1972  */
1973 define( 'TS_EXIF', 5 );
1974
1975 /**
1976  * Oracle format time.
1977  */
1978 define( 'TS_ORACLE', 6 );
1979
1980 /**
1981  * Postgres format time.
1982  */
1983 define( 'TS_POSTGRES', 7 );
1984
1985 /**
1986  * DB2 format time
1987  */
1988 define( 'TS_DB2', 8 );
1989
1990 /**
1991  * ISO 8601 basic format with no timezone: 19860209T200000Z
1992  *
1993  * This is used by ResourceLoader
1994  */
1995 define( 'TS_ISO_8601_BASIC', 9 );
1996
1997 /**
1998  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
1999  *                    function will autodetect which format is supplied and act
2000  *                    accordingly.
2001  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2002  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2003  */
2004 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2005         $uts = 0;
2006         $da = array();
2007         $strtime = '';
2008
2009         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2010                 $uts = time();
2011                 $strtime = "@$uts";
2012         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2013                 # TS_DB
2014         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2015                 # TS_EXIF
2016         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2017                 # TS_MW
2018         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2019                 # TS_UNIX
2020                 $uts = $ts;
2021                 $strtime = "@$ts"; // Undocumented?
2022         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2023                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2024                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2025                                 str_replace( '+00:00', 'UTC', $ts ) );
2026         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2027                 # TS_ISO_8601
2028         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2029                 #TS_ISO_8601_BASIC
2030         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2031                 # TS_POSTGRES
2032         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2033                 # TS_POSTGRES
2034         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2035                 # TS_DB2
2036         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2037                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2038                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2039                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2040                 # The regex is a superset of rfc2822 for readability
2041                 $strtime = strtok( $ts, ';' );
2042         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2043                 # TS_RFC850
2044                 $strtime = $ts;
2045         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2046                 # asctime
2047                 $strtime = $ts;
2048         } else {
2049                 # Bogus value...
2050                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2051
2052                 return false;
2053         }
2054
2055
2056
2057         static $formats = array(
2058                 TS_UNIX => 'U',
2059                 TS_MW => 'YmdHis',
2060                 TS_DB => 'Y-m-d H:i:s',
2061                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2062                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2063                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2064                 TS_RFC2822 => 'D, d M Y H:i:s',
2065                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2066                 TS_POSTGRES => 'Y-m-d H:i:s',
2067                 TS_DB2 => 'Y-m-d H:i:s',
2068         );
2069
2070         if ( !isset( $formats[$outputtype] ) ) {
2071                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2072         }
2073
2074         if ( function_exists( "date_create" ) ) {
2075                 if ( count( $da ) ) {
2076                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2077                                 (int)$da[1], (int)$da[2], (int)$da[3],
2078                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2079
2080                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2081                 } elseif ( $strtime ) {
2082                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2083                 } else {
2084                         return false;
2085                 }
2086
2087                 if ( !$d ) {
2088                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2089                         return false;
2090                 }
2091
2092                 $output = $d->format( $formats[$outputtype] );
2093         } else {
2094                 if ( count( $da ) ) {
2095                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2096                         // We may want to handle that explicitly at some point
2097                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2098                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2099                 } elseif ( $strtime ) {
2100                         $uts = strtotime( $strtime );
2101                 }
2102
2103                 if ( $uts === false ) {
2104                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2105                         return false;
2106                 }
2107
2108                 if ( TS_UNIX == $outputtype ) {
2109                         return $uts;
2110                 }
2111                 $output = gmdate( $formats[$outputtype], $uts );
2112         }
2113
2114         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2115                 $output .= ' GMT';
2116         }
2117
2118         return $output;
2119 }
2120
2121 /**
2122  * Return a formatted timestamp, or null if input is null.
2123  * For dealing with nullable timestamp columns in the database.
2124  * @param $outputtype Integer
2125  * @param $ts String
2126  * @return String
2127  */
2128 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2129         if( is_null( $ts ) ) {
2130                 return null;
2131         } else {
2132                 return wfTimestamp( $outputtype, $ts );
2133         }
2134 }
2135
2136 /**
2137  * Check if the operating system is Windows
2138  *
2139  * @return Bool: true if it's Windows, False otherwise.
2140  */
2141 function wfIsWindows() {
2142         static $isWindows = null;
2143         if ( $isWindows === null ) {
2144                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2145         }
2146         return $isWindows;
2147 }
2148
2149 /**
2150  * Swap two variables
2151  */
2152 function swap( &$x, &$y ) {
2153         $z = $x;
2154         $x = $y;
2155         $y = $z;
2156 }
2157
2158 function wfGetCachedNotice( $name ) {
2159         global $wgOut, $wgRenderHashAppend, $parserMemc;
2160         $fname = 'wfGetCachedNotice';
2161         wfProfileIn( $fname );
2162
2163         $needParse = false;
2164
2165         if( $name === 'default' ) {
2166                 // special case
2167                 global $wgSiteNotice;
2168                 $notice = $wgSiteNotice;
2169                 if( empty( $notice ) ) {
2170                         wfProfileOut( $fname );
2171                         return false;
2172                 }
2173         } else {
2174                 $notice = wfMsgForContentNoTrans( $name );
2175                 if( wfEmptyMsg( $name, $notice ) || $notice == '-' ) {
2176                         wfProfileOut( $fname );
2177                         return( false );
2178                 }
2179         }
2180
2181         // Use the extra hash appender to let eg SSL variants separately cache.
2182         $key = wfMemcKey( $name . $wgRenderHashAppend );
2183         $cachedNotice = $parserMemc->get( $key );
2184         if( is_array( $cachedNotice ) ) {
2185                 if( md5( $notice ) == $cachedNotice['hash'] ) {
2186                         $notice = $cachedNotice['html'];
2187                 } else {
2188                         $needParse = true;
2189                 }
2190         } else {
2191                 $needParse = true;
2192         }
2193
2194         if( $needParse ) {
2195                 if( is_object( $wgOut ) ) {
2196                         $parsed = $wgOut->parse( $notice );
2197                         $parserMemc->set( $key, array( 'html' => $parsed, 'hash' => md5( $notice ) ), 600 );
2198                         $notice = $parsed;
2199                 } else {
2200                         wfDebug( 'wfGetCachedNotice called for ' . $name . ' with no $wgOut available' . "\n" );
2201                         $notice = '';
2202                 }
2203         }
2204         $notice = '<div id="localNotice">' .$notice . '</div>';
2205         wfProfileOut( $fname );
2206         return $notice;
2207 }
2208
2209 function wfGetNamespaceNotice() {
2210         global $wgTitle;
2211
2212         # Paranoia
2213         if ( !isset( $wgTitle ) || !is_object( $wgTitle ) ) {
2214                 return '';
2215         }
2216
2217         $fname = 'wfGetNamespaceNotice';
2218         wfProfileIn( $fname );
2219
2220         $key = 'namespacenotice-' . $wgTitle->getNsText();
2221         $namespaceNotice = wfGetCachedNotice( $key );
2222         if ( $namespaceNotice && substr( $namespaceNotice, 0, 7 ) != '<p>&lt;' ) {
2223                 $namespaceNotice = '<div id="namespacebanner">' . $namespaceNotice . '</div>';
2224         } else {
2225                 $namespaceNotice = '';
2226         }
2227
2228         wfProfileOut( $fname );
2229         return $namespaceNotice;
2230 }
2231
2232 function wfGetSiteNotice() {
2233         global $wgUser;
2234         $fname = 'wfGetSiteNotice';
2235         wfProfileIn( $fname );
2236         $siteNotice = '';
2237
2238         if( wfRunHooks( 'SiteNoticeBefore', array( &$siteNotice ) ) ) {
2239                 if( is_object( $wgUser ) && $wgUser->isLoggedIn() ) {
2240                         $siteNotice = wfGetCachedNotice( 'sitenotice' );
2241                 } else {
2242                         $anonNotice = wfGetCachedNotice( 'anonnotice' );
2243                         if( !$anonNotice ) {
2244                                 $siteNotice = wfGetCachedNotice( 'sitenotice' );
2245                         } else {
2246                                 $siteNotice = $anonNotice;
2247                         }
2248                 }
2249                 if( !$siteNotice ) {
2250                         $siteNotice = wfGetCachedNotice( 'default' );
2251                 }
2252         }
2253
2254         wfRunHooks( 'SiteNoticeAfter', array( &$siteNotice ) );
2255         wfProfileOut( $fname );
2256         return $siteNotice;
2257 }
2258
2259 /**
2260  * BC wrapper for MimeMagic::singleton()
2261  * @deprecated No longer needed as of 1.17 (r68836). Remove in 1.19.
2262  */
2263 function &wfGetMimeMagic() {
2264         wfDeprecated( __FUNCTION__ );
2265         return MimeMagic::singleton();
2266 }
2267
2268 /**
2269  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2270  * TEMP environment variables are then checked in sequence, and if none are set
2271  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2272  * or C:\Windows\Temp for Windows and hope for the best.
2273  * It is common to call it with tempnam().
2274  *
2275  * NOTE: When possible, use instead the tmpfile() function to create
2276  * temporary files to avoid race conditions on file creation, etc.
2277  *
2278  * @return String
2279  */
2280 function wfTempDir() {
2281         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2282                 $tmp = getenv( $var );
2283                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2284                         return $tmp;
2285                 }
2286         }
2287         if( function_exists( 'sys_get_temp_dir' ) ) {
2288                 return sys_get_temp_dir();
2289         }
2290         # Usual defaults
2291         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2292 }
2293
2294 /**
2295  * Make directory, and make all parent directories if they don't exist
2296  *
2297  * @param $dir String: full path to directory to create
2298  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2299  * @param $caller String: optional caller param for debugging.
2300  * @return bool
2301  */
2302 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2303         global $wgDirectoryMode;
2304
2305         if ( !is_null( $caller ) ) {
2306                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2307         }
2308
2309         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2310                 return true;
2311         }
2312
2313         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2314
2315         if ( is_null( $mode ) ) {
2316                 $mode = $wgDirectoryMode;
2317         }
2318
2319         // Turn off the normal warning, we're doing our own below
2320         wfSuppressWarnings();
2321         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2322         wfRestoreWarnings();
2323
2324         if( !$ok ) {
2325                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2326                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2327         }
2328         return $ok;
2329 }
2330
2331 /**
2332  * Increment a statistics counter
2333  */
2334 function wfIncrStats( $key ) {
2335         global $wgStatsMethod;
2336
2337         if( $wgStatsMethod == 'udp' ) {
2338                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname;
2339                 static $socket;
2340                 if ( !$socket ) {
2341                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2342                         $statline = "stats/{$wgDBname} - 1 1 1 1 1 -total\n";
2343                         socket_sendto(
2344                                 $socket,
2345                                 $statline,
2346                                 strlen( $statline ),
2347                                 0,
2348                                 $wgUDPProfilerHost,
2349                                 $wgUDPProfilerPort
2350                         );
2351                 }
2352                 $statline = "stats/{$wgDBname} - 1 1 1 1 1 {$key}\n";
2353                 wfSuppressWarnings();
2354                 socket_sendto(
2355                         $socket,
2356                         $statline,
2357                         strlen( $statline ),
2358                         0,
2359                         $wgUDPProfilerHost,
2360                         $wgUDPProfilerPort
2361                 );
2362                 wfRestoreWarnings();
2363         } elseif( $wgStatsMethod == 'cache' ) {
2364                 global $wgMemc;
2365                 $key = wfMemcKey( 'stats', $key );
2366                 if ( is_null( $wgMemc->incr( $key ) ) ) {
2367                         $wgMemc->add( $key, 1 );
2368                 }
2369         } else {
2370                 // Disabled
2371         }
2372 }
2373
2374 /**
2375  * @param $nr Mixed: the number to format
2376  * @param $acc Integer: the number of digits after the decimal point, default 2
2377  * @param $round Boolean: whether or not to round the value, default true
2378  * @return float
2379  */
2380 function wfPercent( $nr, $acc = 2, $round = true ) {
2381         $ret = sprintf( "%.${acc}f", $nr );
2382         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2383 }
2384
2385 /**
2386  * Encrypt a username/password.
2387  *
2388  * @param $userid Integer: ID of the user
2389  * @param $password String: password of the user
2390  * @return String: hashed password
2391  * @deprecated Use User::crypt() or User::oldCrypt() instead
2392  */
2393 function wfEncryptPassword( $userid, $password ) {
2394         wfDeprecated(__FUNCTION__);
2395         # Just wrap around User::oldCrypt()
2396         return User::oldCrypt( $password, $userid );
2397 }
2398
2399 /**
2400  * Appends to second array if $value differs from that in $default
2401  */
2402 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
2403         if ( is_null( $changed ) ) {
2404                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
2405         }
2406         if ( $default[$key] !== $value ) {
2407                 $changed[$key] = $value;
2408         }
2409 }
2410
2411 /**
2412  * Since wfMsg() and co suck, they don't return false if the message key they
2413  * looked up didn't exist but a XHTML string, this function checks for the
2414  * nonexistance of messages by looking at wfMsg() output
2415  *
2416  * @param $key      String: the message key looked up
2417  * @return Boolean True if the message *doesn't* exist.
2418  */
2419 function wfEmptyMsg( $key ) {
2420         global $wgMessageCache;
2421         return $wgMessageCache->get( $key, /*useDB*/true, /*content*/false ) === false;
2422 }
2423
2424 /**
2425  * Find out whether or not a mixed variable exists in a string
2426  *
2427  * @param $needle String
2428  * @param $str String
2429  * @return Boolean
2430  */
2431 function in_string( $needle, $str ) {
2432         return strpos( $str, $needle ) !== false;
2433 }
2434
2435 function wfSpecialList( $page, $details ) {
2436         global $wgContLang;
2437         $details = $details ? ' ' . $wgContLang->getDirMark() . "($details)" : '';
2438         return $page . $details;
2439 }
2440
2441 /**
2442  * Returns a regular expression of url protocols
2443  *
2444  * @return String
2445  */
2446 function wfUrlProtocols() {
2447         global $wgUrlProtocols;
2448
2449         static $retval = null;
2450         if ( !is_null( $retval ) ) {
2451                 return $retval;
2452         }
2453
2454         // Support old-style $wgUrlProtocols strings, for backwards compatibility
2455         // with LocalSettings files from 1.5
2456         if ( is_array( $wgUrlProtocols ) ) {
2457                 $protocols = array();
2458                 foreach ( $wgUrlProtocols as $protocol ) {
2459                         $protocols[] = preg_quote( $protocol, '/' );
2460                 }
2461
2462                 $retval = implode( '|', $protocols );
2463         } else {
2464                 $retval = $wgUrlProtocols;
2465         }
2466         return $retval;
2467 }
2468
2469 /**
2470  * Safety wrapper around ini_get() for boolean settings.
2471  * The values returned from ini_get() are pre-normalized for settings
2472  * set via php.ini or php_flag/php_admin_flag... but *not*
2473  * for those set via php_value/php_admin_value.
2474  *
2475  * It's fairly common for people to use php_value instead of php_flag,
2476  * which can leave you with an 'off' setting giving a false positive
2477  * for code that just takes the ini_get() return value as a boolean.
2478  *
2479  * To make things extra interesting, setting via php_value accepts
2480  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2481  * Unrecognized values go false... again opposite PHP's own coercion
2482  * from string to bool.
2483  *
2484  * Luckily, 'properly' set settings will always come back as '0' or '1',
2485  * so we only have to worry about them and the 'improper' settings.
2486  *
2487  * I frickin' hate PHP... :P
2488  *
2489  * @param $setting String
2490  * @return Bool
2491  */
2492 function wfIniGetBool( $setting ) {
2493         $val = ini_get( $setting );
2494         // 'on' and 'true' can't have whitespace around them, but '1' can.
2495         return strtolower( $val ) == 'on'
2496                 || strtolower( $val ) == 'true'
2497                 || strtolower( $val ) == 'yes'
2498                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2499 }
2500
2501 /**
2502  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2503  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2504  *
2505  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2506  *                          should be omitted
2507  * @return Bool - Whether or not the extension is loaded
2508  */
2509 function wfDl( $extension ) {
2510         if( extension_loaded( $extension ) ) {
2511                 return true;
2512         }
2513
2514         $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2515                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2516
2517         if( $canDl ) {
2518                 wfSuppressWarnings();
2519                 dl( $extension . '.' . PHP_SHLIB_SUFFIX );
2520                 wfRestoreWarnings();
2521         }
2522         return extension_loaded( $extension );
2523 }
2524
2525 /**
2526  * Execute a shell command, with time and memory limits mirrored from the PHP
2527  * configuration if supported.
2528  * @param $cmd String Command line, properly escaped for shell.
2529  * @param &$retval optional, will receive the program's exit code.
2530  *                 (non-zero is usually failure)
2531  * @param $environ Array optional environment variables which should be
2532  *                 added to the executed command environment.
2533  * @return collected stdout as a string (trailing newlines stripped)
2534  */
2535 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2536         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2537
2538         static $disabled;
2539         if ( is_null( $disabled ) ) {
2540                 $disabled = false;
2541                 if( wfIniGetBool( 'safe_mode' ) ) {
2542                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2543                         $disabled = 'safemode';
2544                 } else {
2545                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2546                         $functions = array_map( 'trim', $functions );
2547                         $functions = array_map( 'strtolower', $functions );
2548                         if ( in_array( 'passthru', $functions ) ) {
2549                                 wfDebug( "passthru is in disabled_functions\n" );
2550                                 $disabled = 'passthru';
2551                         }
2552                 }
2553         }
2554         if ( $disabled ) {
2555                 $retval = 1;
2556                 return $disabled == 'safemode' ?
2557                         'Unable to run external programs in safe mode.' :
2558                         'Unable to run external programs, passthru() is disabled.';
2559         }
2560
2561         wfInitShellLocale();
2562
2563         $envcmd = '';
2564         foreach( $environ as $k => $v ) {
2565                 if ( wfIsWindows() ) {
2566                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2567                          * appear in the environment variable, so we must use carat escaping as documented in
2568                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2569                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2570                          * are listed there but doesn't appear to need it.
2571                          */
2572                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2573                 } else {
2574                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2575                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2576                          */
2577                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2578                 }
2579         }
2580         $cmd = $envcmd . $cmd;
2581
2582         if ( wfIsWindows() ) {
2583                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2584                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2585                 {
2586                         # Hack to work around PHP's flawed invocation of cmd.exe
2587                         # http://news.php.net/php.internals/21796
2588                         # Windows 9x doesn't accept any kind of quotes
2589                         $cmd = '"' . $cmd . '"';
2590                 }
2591         } elseif ( php_uname( 's' ) == 'Linux' ) {
2592                 $time = intval( $wgMaxShellTime );
2593                 $mem = intval( $wgMaxShellMemory );
2594                 $filesize = intval( $wgMaxShellFileSize );
2595
2596                 if ( $time > 0 && $mem > 0 ) {
2597                         $script = "$IP/bin/ulimit4.sh";
2598                         if ( is_executable( $script ) ) {
2599                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2600                         }
2601                 }
2602         }
2603         wfDebug( "wfShellExec: $cmd\n" );
2604
2605         $retval = 1; // error by default?
2606         ob_start();
2607         passthru( $cmd, $retval );
2608         $output = ob_get_contents();
2609         ob_end_clean();
2610
2611         if ( $retval == 127 ) {
2612                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2613         }
2614         return $output;
2615 }
2616
2617 /**
2618  * Workaround for http://bugs.php.net/bug.php?id=45132
2619  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2620  */
2621 function wfInitShellLocale() {
2622         static $done = false;
2623         if ( $done ) {
2624                 return;
2625         }
2626         $done = true;
2627         global $wgShellLocale;
2628         if ( !wfIniGetBool( 'safe_mode' ) ) {
2629                 putenv( "LC_CTYPE=$wgShellLocale" );
2630                 setlocale( LC_CTYPE, $wgShellLocale );
2631         }
2632 }
2633
2634 /**
2635  * This function works like "use VERSION" in Perl, the program will die with a
2636  * backtrace if the current version of PHP is less than the version provided
2637  *
2638  * This is useful for extensions which due to their nature are not kept in sync
2639  * with releases, and might depend on other versions of PHP than the main code
2640  *
2641  * Note: PHP might die due to parsing errors in some cases before it ever
2642  *       manages to call this function, such is life
2643  *
2644  * @see perldoc -f use
2645  *
2646  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2647  *                 a float
2648  */
2649 function wfUsePHP( $req_ver ) {
2650         $php_ver = PHP_VERSION;
2651
2652         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2653                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2654         }
2655 }
2656
2657 /**
2658  * This function works like "use VERSION" in Perl except it checks the version
2659  * of MediaWiki, the program will die with a backtrace if the current version
2660  * of MediaWiki is less than the version provided.
2661  *
2662  * This is useful for extensions which due to their nature are not kept in sync
2663  * with releases
2664  *
2665  * @see perldoc -f use
2666  *
2667  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2668  *                 a float
2669  */
2670 function wfUseMW( $req_ver ) {
2671         global $wgVersion;
2672
2673         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2674                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2675         }
2676 }
2677
2678 /**
2679  * Return the final portion of a pathname.
2680  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2681  * http://bugs.php.net/bug.php?id=33898
2682  *
2683  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2684  * We'll consider it so always, as we don't want \s in our Unix paths either.
2685  *
2686  * @param $path String
2687  * @param $suffix String: to remove if present
2688  * @return String
2689  */
2690 function wfBaseName( $path, $suffix = '' ) {
2691         $encSuffix = ( $suffix == '' )
2692                 ? ''
2693                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2694         $matches = array();
2695         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2696                 return $matches[1];
2697         } else {
2698                 return '';
2699         }
2700 }
2701
2702 /**
2703  * Generate a relative path name to the given file.
2704  * May explode on non-matching case-insensitive paths,
2705  * funky symlinks, etc.
2706  *
2707  * @param $path String: absolute destination path including target filename
2708  * @param $from String: Absolute source path, directory only
2709  * @return String
2710  */
2711 function wfRelativePath( $path, $from ) {
2712         // Normalize mixed input on Windows...
2713         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2714         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2715
2716         // Trim trailing slashes -- fix for drive root
2717         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2718         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2719
2720         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2721         $against = explode( DIRECTORY_SEPARATOR, $from );
2722
2723         if( $pieces[0] !== $against[0] ) {
2724                 // Non-matching Windows drive letters?
2725                 // Return a full path.
2726                 return $path;
2727         }
2728
2729         // Trim off common prefix
2730         while( count( $pieces ) && count( $against )
2731                 && $pieces[0] == $against[0] ) {
2732                 array_shift( $pieces );
2733                 array_shift( $against );
2734         }
2735
2736         // relative dots to bump us to the parent
2737         while( count( $against ) ) {
2738                 array_unshift( $pieces, '..' );
2739                 array_shift( $against );
2740         }
2741
2742         array_push( $pieces, wfBaseName( $path ) );
2743
2744         return implode( DIRECTORY_SEPARATOR, $pieces );
2745 }
2746
2747 /**
2748  * Backwards array plus for people who haven't bothered to read the PHP manual
2749  * XXX: will not darn your socks for you.
2750  *
2751  * @param $array1 Array
2752  * @param [$array2, [...]] Arrays
2753  * @return Array
2754  */
2755 function wfArrayMerge( $array1/* ... */ ) {
2756         $args = func_get_args();
2757         $args = array_reverse( $args, true );
2758         $out = array();
2759         foreach ( $args as $arg ) {
2760                 $out += $arg;
2761         }
2762         return $out;
2763 }
2764
2765 /**
2766  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
2767  * e.g.
2768  *      wfMergeErrorArrays(
2769  *              array( array( 'x' ) ),
2770  *              array( array( 'x', '2' ) ),
2771  *              array( array( 'x' ) ),
2772  *              array( array( 'y') )
2773  *      );
2774  * returns:
2775  *              array(
2776  *              array( 'x', '2' ),
2777  *              array( 'x' ),
2778  *              array( 'y' )
2779  *      )
2780  */
2781 function wfMergeErrorArrays( /*...*/ ) {
2782         $args = func_get_args();
2783         $out = array();
2784         foreach ( $args as $errors ) {
2785                 foreach ( $errors as $params ) {
2786                         # FIXME: sometimes get nested arrays for $params,
2787                         # which leads to E_NOTICEs
2788                         $spec = implode( "\t", $params );
2789                         $out[$spec] = $params;
2790                 }
2791         }
2792         return array_values( $out );
2793 }
2794
2795 /**
2796  * parse_url() work-alike, but non-broken.  Differences:
2797  *
2798  * 1) Does not raise warnings on bad URLs (just returns false)
2799  * 2) Handles protocols that don't use :// (e.g., mailto: and news:) correctly
2800  * 3) Adds a "delimiter" element to the array, either '://' or ':' (see (2))
2801  *
2802  * @param $url String: a URL to parse
2803  * @return Array: bits of the URL in an associative array, per PHP docs
2804  */
2805 function wfParseUrl( $url ) {
2806         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
2807         wfSuppressWarnings();
2808         $bits = parse_url( $url );
2809         wfRestoreWarnings();
2810         if ( !$bits ) {
2811                 return false;
2812         }
2813
2814         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
2815         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
2816                 $bits['delimiter'] = '://';
2817         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
2818                 $bits['delimiter'] = ':';
2819                 // parse_url detects for news: and mailto: the host part of an url as path
2820                 // We have to correct this wrong detection
2821                 if ( isset( $bits['path'] ) ) {
2822                         $bits['host'] = $bits['path'];
2823                         $bits['path'] = '';
2824                 }
2825         } else {
2826                 return false;
2827         }
2828
2829         return $bits;
2830 }
2831
2832 /**
2833  * Make a URL index, appropriate for the el_index field of externallinks.
2834  */
2835 function wfMakeUrlIndex( $url ) {
2836         $bits = wfParseUrl( $url );
2837
2838         // Reverse the labels in the hostname, convert to lower case
2839         // For emails reverse domainpart only
2840         if ( $bits['scheme'] == 'mailto' ) {
2841                 $mailparts = explode( '@', $bits['host'], 2 );
2842                 if ( count( $mailparts ) === 2 ) {
2843                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
2844                 } else {
2845                         // No domain specified, don't mangle it
2846                         $domainpart = '';
2847                 }
2848                 $reversedHost = $domainpart . '@' . $mailparts[0];
2849         } else {
2850                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
2851         }
2852         // Add an extra dot to the end
2853         // Why? Is it in wrong place in mailto links?
2854         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
2855                 $reversedHost .= '.';
2856         }
2857         // Reconstruct the pseudo-URL
2858         $prot = $bits['scheme'];
2859         $index = $prot . $bits['delimiter'] . $reversedHost;
2860         // Leave out user and password. Add the port, path, query and fragment
2861         if ( isset( $bits['port'] ) ) {
2862                 $index .= ':' . $bits['port'];
2863         }
2864         if ( isset( $bits['path'] ) ) {
2865                 $index .= $bits['path'];
2866         } else {
2867                 $index .= '/';
2868         }
2869         if ( isset( $bits['query'] ) ) {
2870                 $index .= '?' . $bits['query'];
2871         }
2872         if ( isset( $bits['fragment'] ) ) {
2873                 $index .= '#' . $bits['fragment'];
2874         }
2875         return $index;
2876 }
2877
2878 /**
2879  * Do any deferred updates and clear the list
2880  *
2881  * @param $commit String: set to 'commit' to commit after every update to
2882  *                prevent lock contention
2883  */
2884 function wfDoUpdates( $commit = '' ) {
2885         global $wgDeferredUpdateList;
2886
2887         wfProfileIn( __METHOD__ );
2888
2889         // No need to get master connections in case of empty updates array
2890         if ( !count( $wgDeferredUpdateList ) ) {
2891                 wfProfileOut( __METHOD__ );
2892                 return;
2893         }
2894
2895         $doCommit = $commit == 'commit';
2896         if ( $doCommit ) {
2897                 $dbw = wfGetDB( DB_MASTER );
2898         }
2899
2900         foreach ( $wgDeferredUpdateList as $update ) {
2901                 $update->doUpdate();
2902
2903                 if ( $doCommit && $dbw->trxLevel() ) {
2904                         $dbw->commit();
2905                 }
2906         }
2907
2908         $wgDeferredUpdateList = array();
2909         wfProfileOut( __METHOD__ );
2910 }
2911
2912 /**
2913  * Convert an arbitrarily-long digit string from one numeric base
2914  * to another, optionally zero-padding to a minimum column width.
2915  *
2916  * Supports base 2 through 36; digit values 10-36 are represented
2917  * as lowercase letters a-z. Input is case-insensitive.
2918  *
2919  * @param $input String: of digits
2920  * @param $sourceBase Integer: 2-36
2921  * @param $destBase Integer: 2-36
2922  * @param $pad Integer: 1 or greater
2923  * @param $lowercase Boolean
2924  * @return String or false on invalid input
2925  */
2926 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2927         $input = strval( $input );
2928         if( $sourceBase < 2 ||
2929                 $sourceBase > 36 ||
2930                 $destBase < 2 ||
2931                 $destBase > 36 ||
2932                 $pad < 1 ||
2933                 $sourceBase != intval( $sourceBase ) ||
2934                 $destBase != intval( $destBase ) ||
2935                 $pad != intval( $pad ) ||
2936                 !is_string( $input ) ||
2937                 $input == '' ) {
2938                 return false;
2939         }
2940         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2941         $inDigits = array();
2942         $outChars = '';
2943
2944         // Decode and validate input string
2945         $input = strtolower( $input );
2946         for( $i = 0; $i < strlen( $input ); $i++ ) {
2947                 $n = strpos( $digitChars, $input{$i} );
2948                 if( $n === false || $n > $sourceBase ) {
2949                         return false;
2950                 }
2951                 $inDigits[] = $n;
2952         }
2953
2954         // Iterate over the input, modulo-ing out an output digit
2955         // at a time until input is gone.
2956         while( count( $inDigits ) ) {
2957                 $work = 0;
2958                 $workDigits = array();
2959
2960                 // Long division...
2961                 foreach( $inDigits as $digit ) {
2962                         $work *= $sourceBase;
2963                         $work += $digit;
2964
2965                         if( $work < $destBase ) {
2966                                 // Gonna need to pull another digit.
2967                                 if( count( $workDigits ) ) {
2968                                         // Avoid zero-padding; this lets us find
2969                                         // the end of the input very easily when
2970                                         // length drops to zero.
2971                                         $workDigits[] = 0;
2972                                 }
2973                         } else {
2974                                 // Finally! Actual division!
2975                                 $workDigits[] = intval( $work / $destBase );
2976
2977                                 // Isn't it annoying that most programming languages
2978                                 // don't have a single divide-and-remainder operator,
2979                                 // even though the CPU implements it that way?
2980                                 $work = $work % $destBase;
2981                         }
2982                 }
2983
2984                 // All that division leaves us with a remainder,
2985                 // which is conveniently our next output digit.
2986                 $outChars .= $digitChars[$work];
2987
2988                 // And we continue!
2989                 $inDigits = $workDigits;
2990         }
2991
2992         while( strlen( $outChars ) < $pad ) {
2993                 $outChars .= '0';
2994         }
2995
2996         return strrev( $outChars );
2997 }
2998
2999 /**
3000  * Create an object with a given name and an array of construct parameters
3001  * @param $name String
3002  * @param $p Array: parameters
3003  */
3004 function wfCreateObject( $name, $p ) {
3005         $p = array_values( $p );
3006         switch ( count( $p ) ) {
3007                 case 0:
3008                         return new $name;
3009                 case 1:
3010                         return new $name( $p[0] );
3011                 case 2:
3012                         return new $name( $p[0], $p[1] );
3013                 case 3:
3014                         return new $name( $p[0], $p[1], $p[2] );
3015                 case 4:
3016                         return new $name( $p[0], $p[1], $p[2], $p[3] );
3017                 case 5:
3018                         return new $name( $p[0], $p[1], $p[2], $p[3], $p[4] );
3019                 case 6:
3020                         return new $name( $p[0], $p[1], $p[2], $p[3], $p[4], $p[5] );
3021                 default:
3022                         throw new MWException( 'Too many arguments to construtor in wfCreateObject' );
3023         }
3024 }
3025
3026 function wfHttpOnlySafe() {
3027         global $wgHttpOnlyBlacklist;
3028         if( !version_compare( '5.2', PHP_VERSION, '<' ) ) {
3029                 return false;
3030         }
3031
3032         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3033                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3034                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3035                                 return false;
3036                         }
3037                 }
3038         }
3039
3040         return true;
3041 }
3042
3043 /**
3044  * Initialise php session
3045  */
3046 function wfSetupSession( $sessionId = false ) {
3047         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3048                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3049         if( $wgSessionsInMemcached ) {
3050                 require_once( 'MemcachedSessions.php' );
3051         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3052                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3053                 # hasn't already been set to the desired value (that causes errors)
3054                 ini_set( 'session.save_handler', $wgSessionHandler );
3055         }
3056         $httpOnlySafe = wfHttpOnlySafe();
3057         wfDebugLog( 'cookie',
3058                 'session_set_cookie_params: "' . implode( '", "',
3059                         array(
3060                                 0,
3061                                 $wgCookiePath,
3062                                 $wgCookieDomain,
3063                                 $wgCookieSecure,
3064                                 $httpOnlySafe && $wgCookieHttpOnly ) ) . '"' );
3065         if( $httpOnlySafe && $wgCookieHttpOnly ) {
3066                 session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3067         } else {
3068                 // PHP 5.1 throws warnings if you pass the HttpOnly parameter for 5.2.
3069                 session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure );
3070         }
3071         session_cache_limiter( 'private, must-revalidate' );
3072         if ( $sessionId ) {
3073                 session_id( $sessionId );
3074         }
3075         wfSuppressWarnings();
3076         session_start();
3077         wfRestoreWarnings();
3078 }
3079
3080 /**
3081  * Get an object from the precompiled serialized directory
3082  *
3083  * @return Mixed: the variable on success, false on failure
3084  */
3085 function wfGetPrecompiledData( $name ) {
3086         global $IP;
3087
3088         $file = "$IP/serialized/$name";
3089         if ( file_exists( $file ) ) {
3090                 $blob = file_get_contents( $file );
3091                 if ( $blob ) {
3092                         return unserialize( $blob );
3093                 }
3094         }
3095         return false;
3096 }
3097
3098 function wfGetCaller( $level = 2 ) {
3099         $backtrace = wfDebugBacktrace();
3100         if ( isset( $backtrace[$level] ) ) {
3101                 return wfFormatStackFrame( $backtrace[$level] );
3102         } else {
3103                 $caller = 'unknown';
3104         }
3105         return $caller;
3106 }
3107
3108 /**
3109  * Return a string consisting of callers in the stack. Useful sometimes
3110  * for profiling specific points.
3111  *
3112  * @param $limit The maximum depth of the stack frame to return, or false for
3113  *               the entire stack.
3114  */
3115 function wfGetAllCallers( $limit = 3 ) {
3116         $trace = array_reverse( wfDebugBacktrace() );
3117         if ( !$limit || $limit > count( $trace ) - 1 ) {
3118                 $limit = count( $trace ) - 1;
3119         }
3120         $trace = array_slice( $trace, -$limit - 1, $limit );
3121         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
3122 }
3123
3124 /**
3125  * Return a string representation of frame
3126  */
3127 function wfFormatStackFrame( $frame ) {
3128         return isset( $frame['class'] ) ?
3129                 $frame['class'] . '::' . $frame['function'] :
3130                 $frame['function'];
3131 }
3132
3133 /**
3134  * Get a cache key
3135  */
3136 function wfMemcKey( /*... */ ) {
3137         $args = func_get_args();
3138         $key = wfWikiID() . ':' . implode( ':', $args );
3139         $key = str_replace( ' ', '_', $key );
3140         return $key;
3141 }
3142
3143 /**
3144  * Get a cache key for a foreign DB
3145  */
3146 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3147         $args = array_slice( func_get_args(), 2 );
3148         if ( $prefix ) {
3149                 $key = "$db-$prefix:" . implode( ':', $args );
3150         } else {
3151                 $key = $db . ':' . implode( ':', $args );
3152         }
3153         return $key;
3154 }
3155
3156 /**
3157  * Get an ASCII string identifying this wiki
3158  * This is used as a prefix in memcached keys
3159  */
3160 function wfWikiID() {
3161         global $wgDBprefix, $wgDBname;
3162         if ( $wgDBprefix ) {
3163                 return "$wgDBname-$wgDBprefix";
3164         } else {
3165                 return $wgDBname;
3166         }
3167 }
3168
3169 /**
3170  * Split a wiki ID into DB name and table prefix
3171  */
3172 function wfSplitWikiID( $wiki ) {
3173         $bits = explode( '-', $wiki, 2 );
3174         if ( count( $bits ) < 2 ) {
3175                 $bits[] = '';
3176         }
3177         return $bits;
3178 }
3179
3180 /**
3181  * Get a Database object.
3182  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3183  *            master (for write queries), DB_SLAVE for potentially lagged read
3184  *            queries, or an integer >= 0 for a particular server.
3185  *
3186  * @param $groups Mixed: query groups. An array of group names that this query
3187  *                belongs to. May contain a single string if the query is only
3188  *                in one group.
3189  *
3190  * @param $wiki String: the wiki ID, or false for the current wiki
3191  *
3192  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3193  * will always return the same object, unless the underlying connection or load
3194  * balancer is manually destroyed.
3195  *
3196  * @return DatabaseBase
3197  */
3198 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3199         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3200 }
3201
3202 /**
3203  * Get a load balancer object.
3204  *
3205  * @param $wiki String: wiki ID, or false for the current wiki
3206  * @return LoadBalancer
3207  */
3208 function wfGetLB( $wiki = false ) {
3209         return wfGetLBFactory()->getMainLB( $wiki );
3210 }
3211
3212 /**
3213  * Get the load balancer factory object
3214  * @return LBFactory
3215  */
3216 function &wfGetLBFactory() {
3217         return LBFactory::singleton();
3218 }
3219
3220 /**
3221  * Find a file.
3222  * Shortcut for RepoGroup::singleton()->findFile()
3223  * @param $title String or Title object
3224  * @param $options Associative array of options:
3225  *     time:           requested time for an archived image, or false for the
3226  *                     current version. An image object will be returned which was
3227  *                     created at the specified time.
3228  *
3229  *     ignoreRedirect: If true, do not follow file redirects
3230  *
3231  *     private:        If true, return restricted (deleted) files if the current
3232  *                     user is allowed to view them. Otherwise, such files will not
3233  *                     be found.
3234  *
3235  *     bypassCache:    If true, do not use the process-local cache of File objects
3236  *
3237  * @return File, or false if the file does not exist
3238  */
3239 function wfFindFile( $title, $options = array() ) {
3240         return RepoGroup::singleton()->findFile( $title, $options );
3241 }
3242
3243 /**
3244  * Get an object referring to a locally registered file.
3245  * Returns a valid placeholder object if the file does not exist.
3246  * @param $title Title or String
3247  * @return File, or null if passed an invalid Title
3248  */
3249 function wfLocalFile( $title ) {
3250         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3251 }
3252
3253 /**
3254  * Should low-performance queries be disabled?
3255  *
3256  * @return Boolean
3257  */
3258 function wfQueriesMustScale() {
3259         global $wgMiserMode;
3260         return $wgMiserMode
3261                 || ( SiteStats::pages() > 100000
3262                 && SiteStats::edits() > 1000000
3263                 && SiteStats::users() > 10000 );
3264 }
3265
3266 /**
3267  * Get the path to a specified script file, respecting file
3268  * extensions; this is a wrapper around $wgScriptExtension etc.
3269  *
3270  * @param $script String: script filename, sans extension
3271  * @return String
3272  */
3273 function wfScript( $script = 'index' ) {
3274         global $wgScriptPath, $wgScriptExtension;
3275         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3276 }
3277
3278 /**
3279  * Get the script URL.
3280  *
3281  * @return script URL
3282  */
3283 function wfGetScriptUrl() {
3284         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3285                 #
3286                 # as it was called, minus the query string.
3287                 #
3288                 # Some sites use Apache rewrite rules to handle subdomains,
3289                 # and have PHP set up in a weird way that causes PHP_SELF
3290                 # to contain the rewritten URL instead of the one that the
3291                 # outside world sees.
3292                 #
3293                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3294                 # provides containing the "before" URL.
3295                 return $_SERVER['SCRIPT_NAME'];
3296         } else {
3297                 return $_SERVER['URL'];
3298         }
3299 }
3300
3301 /**
3302  * Convenience function converts boolean values into "true"
3303  * or "false" (string) values
3304  *
3305  * @param $value Boolean
3306  * @return String
3307  */
3308 function wfBoolToStr( $value ) {
3309         return $value ? 'true' : 'false';
3310 }
3311
3312 /**
3313  * Load an extension messages file
3314  * @deprecated in 1.16, warnings in 1.18, remove in 1.20
3315  */
3316 function wfLoadExtensionMessages( $extensionName, $langcode = false ) {
3317         wfDeprecated( __FUNCTION__ );
3318 }
3319
3320 /**
3321  * Get a platform-independent path to the null file, e.g.
3322  * /dev/null
3323  *
3324  * @return string
3325  */
3326 function wfGetNull() {
3327         return wfIsWindows()
3328                 ? 'NUL'
3329                 : '/dev/null';
3330 }
3331
3332 /**
3333  * Displays a maxlag error
3334  *
3335  * @param $host String: server that lags the most
3336  * @param $lag Integer: maxlag (actual)
3337  * @param $maxLag Integer: maxlag (requested)
3338  */
3339 function wfMaxlagError( $host, $lag, $maxLag ) {
3340         global $wgShowHostnames;
3341         header( 'HTTP/1.1 503 Service Unavailable' );
3342         header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
3343         header( 'X-Database-Lag: ' . intval( $lag ) );
3344         header( 'Content-Type: text/plain' );
3345         if( $wgShowHostnames ) {
3346                 echo "Waiting for $host: $lag seconds lagged\n";
3347         } else {
3348                 echo "Waiting for a database server: $lag seconds lagged\n";
3349         }
3350 }
3351
3352 /**
3353  * Throws a warning that $function is deprecated
3354  * @param $function String
3355  * @return null
3356  */
3357 function wfDeprecated( $function ) {
3358         static $functionsWarned = array();
3359         if ( !isset( $functionsWarned[$function] ) ) {
3360                 $functionsWarned[$function] = true;
3361                 wfWarn( "Use of $function is deprecated.", 2 );
3362         }
3363 }
3364
3365 /**
3366  * Send a warning either to the debug log or in a PHP error depending on
3367  * $wgDevelopmentWarnings
3368  *
3369  * @param $msg String: message to send
3370  * @param $callerOffset Integer: number of itmes to go back in the backtrace to
3371  *        find the correct caller (1 = function calling wfWarn, ...)
3372  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3373  *        is true
3374  */
3375 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3376         $callers = wfDebugBacktrace();
3377         if( isset( $callers[$callerOffset + 1] ) ){
3378                 $callerfunc = $callers[$callerOffset + 1];
3379                 $callerfile = $callers[$callerOffset];
3380                 if( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3381                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3382                 } else {
3383                         $file = '(internal function)';
3384                 }
3385                 $func = '';
3386                 if( isset( $callerfunc['class'] ) ) {
3387                         $func .= $callerfunc['class'] . '::';
3388                 }
3389                 if( isset( $callerfunc['function'] ) ) {
3390                         $func .= $callerfunc['function'];
3391                 }
3392                 $msg .= " [Called from $func in $file]";
3393         }
3394
3395         global $wgDevelopmentWarnings;
3396         if ( $wgDevelopmentWarnings ) {
3397                 trigger_error( $msg, $level );
3398         } else {
3399                 wfDebug( "$msg\n" );
3400         }
3401 }
3402
3403 /**
3404  * Sleep until the worst slave's replication lag is less than or equal to
3405  * $maxLag, in seconds.  Use this when updating very large numbers of rows, as
3406  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3407  * a no-op if there are no slaves.
3408  *
3409  * Every time the function has to wait for a slave, it will print a message to
3410  * that effect (and then sleep for a little while), so it's probably not best
3411  * to use this outside maintenance scripts in its present form.
3412  *
3413  * @param $maxLag Integer
3414  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3415  * @return null
3416  */
3417 function wfWaitForSlaves( $maxLag, $wiki = false ) {
3418         if( $maxLag ) {
3419                 $lb = wfGetLB( $wiki );
3420                 list( $host, $lag ) = $lb->getMaxLag( $wiki );
3421                 while( $lag > $maxLag ) {
3422                         wfSuppressWarnings();
3423                         $name = gethostbyaddr( $host );
3424                         wfRestoreWarnings();
3425                         if( $name !== false ) {
3426                                 $host = $name;
3427                         }
3428                         print "Waiting for $host (lagged $lag seconds)...\n";
3429                         sleep( $maxLag );
3430                         list( $host, $lag ) = $lb->getMaxLag();
3431                 }
3432         }
3433 }
3434
3435 /**
3436  * Used to be used for outputting text in the installer/updater
3437  * @deprecated Warnings in 1.19, removal in 1.20
3438  */
3439 function wfOut( $s ) {
3440         global $wgCommandLineMode;
3441         if ( $wgCommandLineMode && !defined( 'MEDIAWIKI_INSTALL' ) ) {
3442                 echo $s;
3443         } else {
3444                 echo htmlspecialchars( $s );
3445         }
3446         flush();
3447 }
3448
3449 /**
3450  * Count down from $n to zero on the terminal, with a one-second pause
3451  * between showing each number. For use in command-line scripts.
3452  */
3453 function wfCountDown( $n ) {
3454         for ( $i = $n; $i >= 0; $i-- ) {
3455                 if ( $i != $n ) {
3456                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3457                 }
3458                 echo $i;
3459                 flush();
3460                 if ( $i ) {
3461                         sleep( 1 );
3462                 }
3463         }
3464         echo "\n";
3465 }
3466
3467 /**
3468  * Generate a random 32-character hexadecimal token.
3469  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3470  *              characters before hashing.
3471  */
3472 function wfGenerateToken( $salt = '' ) {
3473         $salt = serialize( $salt );
3474         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3475 }
3476
3477 /**
3478  * Replace all invalid characters with -
3479  * @param $name Mixed: filename to process
3480  */
3481 function wfStripIllegalFilenameChars( $name ) {
3482         global $wgIllegalFileChars;
3483         $name = wfBaseName( $name );
3484         $name = preg_replace(
3485                 "/[^" . Title::legalChars() . "]" .
3486                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3487                         "/",
3488                 '-',
3489                 $name
3490         );
3491         return $name;
3492 }
3493
3494 /**
3495  * Insert array into another array after the specified *KEY*
3496  * @param $array Array: The array.
3497  * @param $insert Array: The array to insert.
3498  * @param $after Mixed: The key to insert after
3499  */
3500 function wfArrayInsertAfter( $array, $insert, $after ) {
3501         // Find the offset of the element to insert after.
3502         $keys = array_keys( $array );
3503         $offsetByKey = array_flip( $keys );
3504
3505         $offset = $offsetByKey[$after];
3506
3507         // Insert at the specified offset
3508         $before = array_slice( $array, 0, $offset + 1, true );
3509         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
3510
3511         $output = $before + $insert + $after;
3512
3513         return $output;
3514 }
3515
3516 /* Recursively converts the parameter (an object) to an array with the same data */
3517 function wfObjectToArray( $object, $recursive = true ) {
3518         $array = array();
3519         foreach ( get_object_vars( $object ) as $key => $value ) {
3520                 if ( is_object( $value ) && $recursive ) {
3521                         $value = wfObjectToArray( $value );
3522                 }
3523
3524                 $array[$key] = $value;
3525         }
3526
3527         return $array;
3528 }
3529
3530 /**
3531  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3532  * @return Integer value memory was set to.
3533  */
3534 function wfMemoryLimit() {
3535         global $wgMemoryLimit;
3536         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3537         if( $memlimit != -1 ) {
3538                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3539                 if( $conflimit == -1 ) {
3540                         wfDebug( "Removing PHP's memory limit\n" );
3541                         wfSuppressWarnings();
3542                         ini_set( 'memory_limit', $conflimit );
3543                         wfRestoreWarnings();
3544                         return $conflimit;
3545                 } elseif ( $conflimit > $memlimit ) {
3546                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3547                         wfSuppressWarnings();
3548                         ini_set( 'memory_limit', $conflimit );
3549                         wfRestoreWarnings();
3550                         return $conflimit;
3551                 }
3552         }
3553         return $memlimit;
3554 }
3555
3556 /**
3557  * Converts shorthand byte notation to integer form
3558  * @param $string String
3559  * @return Integer
3560  */
3561 function wfShorthandToInteger( $string = '' ) {
3562         $string = trim( $string );
3563         if( $string === '' ) {
3564                 return -1;
3565         }
3566         $last = $string[strlen( $string ) - 1];
3567         $val = intval( $string );
3568         switch( $last ) {
3569                 case 'g':
3570                 case 'G':
3571                         $val *= 1024;
3572                         // break intentionally missing
3573                 case 'm':
3574                 case 'M':
3575                         $val *= 1024;
3576                         // break intentionally missing
3577                 case 'k':
3578                 case 'K':
3579                         $val *= 1024;
3580         }
3581
3582         return $val;
3583 }
3584
3585 /**
3586  * Get the normalised IETF language tag
3587  * @param $code String: The language code.
3588  * @return $langCode String: The language code which complying with BCP 47 standards.
3589  */
3590 function wfBCP47( $code ) {
3591         $codeSegment = explode( '-', $code );
3592         foreach ( $codeSegment as $segNo => $seg ) {
3593                 if ( count( $codeSegment ) > 0 ) {
3594                         // ISO 3166 country code
3595                         if ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3596                                 $codeBCP[$segNo] = strtoupper( $seg );
3597                         // ISO 15924 script code
3598                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3599                                 $codeBCP[$segNo] = ucfirst( $seg );
3600                         // Use lowercase for other cases
3601                         } else {
3602                                 $codeBCP[$segNo] = strtolower( $seg );
3603                         }
3604                 } else {
3605                 // Use lowercase for single segment
3606                         $codeBCP[$segNo] = strtolower( $seg );
3607                 }
3608         }
3609         $langCode = implode( '-', $codeBCP );
3610         return $langCode;
3611 }
3612
3613 function wfArrayMap( $function, $input ) {
3614         $ret = array_map( $function, $input );
3615         foreach ( $ret as $key => $value ) {
3616                 $taint = istainted( $input[$key] );
3617                 if ( $taint ) {
3618                         taint( $ret[$key], $taint );
3619                 }
3620         }
3621         return $ret;
3622 }