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 // Hide compatibility functions from Doxygen
  12 /// @cond
  13
  14 /**
  15  * Compatibility functions
  16  *
  17  * We support PHP 5.2.3 and up.
  18  * Re-implementations of newer functions or functions in non-standard
  19  * PHP extensions may be included here.
  20  */
  21
  22 if( !function_exists( 'iconv' ) ) {
  23         /** @codeCoverageIgnore */
  24         function iconv( $from, $to, $string ) {
  25                 return Fallback::iconv( $from, $to, $string );
  26         }
  27 }
  28
  29 if ( !function_exists( 'mb_substr' ) ) {
  30         /** @codeCoverageIgnore */
  31         function mb_substr( $str, $start, $count='end' ) {
  32                 return Fallback::mb_substr( $str, $start, $count );
  33         }
  34
  35         /** @codeCoverageIgnore */
  36         function mb_substr_split_unicode( $str, $splitPos ) {
  37                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  38         }
  39 }
  40
  41 if ( !function_exists( 'mb_strlen' ) ) {
  42         /** @codeCoverageIgnore */
  43         function mb_strlen( $str, $enc = '' ) {
  44                 return Fallback::mb_strlen( $str, $enc );
  45         }
  46 }
  47
  48 if( !function_exists( 'mb_strpos' ) ) {
  49         /** @codeCoverageIgnore */
  50         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  51                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  52         }
  53
  54 }
  55
  56 if( !function_exists( 'mb_strrpos' ) ) {
  57         /** @codeCoverageIgnore */
  58         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  59                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  60         }
  61 }
  62
  63
  64 // Support for Wietse Venema's taint feature
  65 if ( !function_exists( 'istainted' ) ) {
  66         /** @codeCoverageIgnore */
  67         function istainted( $var ) {
  68                 return 0;
  69         }
  70         /** @codeCoverageIgnore */
  71         function taint( $var, $level = 0 ) {}
  72         /** @codeCoverageIgnore */
  73         function untaint( $var, $level = 0 ) {}
  74         define( 'TC_HTML', 1 );
  75         define( 'TC_SHELL', 1 );
  76         define( 'TC_MYSQL', 1 );
  77         define( 'TC_PCRE', 1 );
  78         define( 'TC_SELF', 1 );
  79 }
  80 /// @endcond
  81
  82 /**
  83  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
  84  */
  85 function wfArrayDiff2( $a, $b ) {
  86         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  87 }
  88
  89 /**
  90  * @param $a
  91  * @param $b
  92  * @return int
  93  */
  94 function wfArrayDiff2_cmp( $a, $b ) {
  95         if ( !is_array( $a ) ) {
  96                 return strcmp( $a, $b );
  97         } elseif ( count( $a ) !== count( $b ) ) {
  98                 return count( $a ) < count( $b ) ? -1 : 1;
  99         } else {
 100                 reset( $a );
 101                 reset( $b );
 102                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 103                         $cmp = strcmp( $valueA, $valueB );
 104                         if ( $cmp !== 0 ) {
 105                                 return $cmp;
 106                         }
 107                 }
 108                 return 0;
 109         }
 110 }
 111
 112 /**
 113  * Array lookup
 114  * Returns an array where the values in the first array are replaced by the
 115  * values in the second array with the corresponding keys
 116  *
 117  * @param $a Array
 118  * @param $b Array
 119  * @return array
 120  */
 121 function wfArrayLookup( $a, $b ) {
 122         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 123 }
 124
 125 /**
 126  * Appends to second array if $value differs from that in $default
 127  *
 128  * @param $key String|Int
 129  * @param $value Mixed
 130  * @param $default Mixed
 131  * @param $changed Array to alter
 132  */
 133 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 134         if ( is_null( $changed ) ) {
 135                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 136         }
 137         if ( $default[$key] !== $value ) {
 138                 $changed[$key] = $value;
 139         }
 140 }
 141
 142 /**
 143  * Backwards array plus for people who haven't bothered to read the PHP manual
 144  * XXX: will not darn your socks for you.
 145  *
 146  * @param $array1 Array
 147  * @param [$array2, [...]] Arrays
 148  * @return Array
 149  */
 150 function wfArrayMerge( $array1/* ... */ ) {
 151         $args = func_get_args();
 152         $args = array_reverse( $args, true );
 153         $out = array();
 154         foreach ( $args as $arg ) {
 155                 $out += $arg;
 156         }
 157         return $out;
 158 }
 159
 160 /**
 161  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 162  * e.g.
 163  *      wfMergeErrorArrays(
 164  *              array( array( 'x' ) ),
 165  *              array( array( 'x', '2' ) ),
 166  *              array( array( 'x' ) ),
 167  *              array( array( 'y') )
 168  *      );
 169  * returns:
 170  *              array(
 171  *              array( 'x', '2' ),
 172  *              array( 'x' ),
 173  *              array( 'y' )
 174  *      )
 175  * @param varargs
 176  * @return Array
 177  */
 178 function wfMergeErrorArrays( /*...*/ ) {
 179         $args = func_get_args();
 180         $out = array();
 181         foreach ( $args as $errors ) {
 182                 foreach ( $errors as $params ) {
 183                         # @todo FIXME: Sometimes get nested arrays for $params,
 184                         # which leads to E_NOTICEs
 185                         $spec = implode( "\t", $params );
 186                         $out[$spec] = $params;
 187                 }
 188         }
 189         return array_values( $out );
 190 }
 191
 192 /**
 193  * Insert array into another array after the specified *KEY*
 194  *
 195  * @param $array Array: The array.
 196  * @param $insert Array: The array to insert.
 197  * @param $after Mixed: The key to insert after
 198  * @return Array
 199  */
 200 function wfArrayInsertAfter( $array, $insert, $after ) {
 201         // Find the offset of the element to insert after.
 202         $keys = array_keys( $array );
 203         $offsetByKey = array_flip( $keys );
 204
 205         $offset = $offsetByKey[$after];
 206
 207         // Insert at the specified offset
 208         $before = array_slice( $array, 0, $offset + 1, true );
 209         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 210
 211         $output = $before + $insert + $after;
 212
 213         return $output;
 214 }
 215
 216 /**
 217  * Recursively converts the parameter (an object) to an array with the same data
 218  *
 219  * @param $objOrArray Object|Array
 220  * @param $recursive Bool
 221  * @return Array
 222  */
 223 function wfObjectToArray( $objOrArray, $recursive = true ) {
 224         $array = array();
 225         if( is_object( $objOrArray ) ) {
 226                 $objOrArray = get_object_vars( $objOrArray );
 227         }
 228         foreach ( $objOrArray as $key => $value ) {
 229                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 230                         $value = wfObjectToArray( $value );
 231                 }
 232
 233                 $array[$key] = $value;
 234         }
 235
 236         return $array;
 237 }
 238
 239 /**
 240  * Wrapper around array_map() which also taints variables
 241  *
 242  * @param  $function Callback
 243  * @param  $input Array
 244  * @return Array
 245  */
 246 function wfArrayMap( $function, $input ) {
 247         $ret = array_map( $function, $input );
 248         foreach ( $ret as $key => $value ) {
 249                 $taint = istainted( $input[$key] );
 250                 if ( $taint ) {
 251                         taint( $ret[$key], $taint );
 252                 }
 253         }
 254         return $ret;
 255 }
 256
 257 /**
 258  * Get a random decimal value between 0 and 1, in a way
 259  * not likely to give duplicate values for any realistic
 260  * number of articles.
 261  *
 262  * @return string
 263  */
 264 function wfRandom() {
 265         # The maximum random value is "only" 2^31-1, so get two random
 266         # values to reduce the chance of dupes
 267         $max = mt_getrandmax() + 1;
 268         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 269                 / $max / $max, 12, '.', '' );
 270         return $rand;
 271 }
 272
 273 /**
 274  * We want some things to be included as literal characters in our title URLs
 275  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 276  * all of the following should be safe:
 277  *
 278  * ;:@&=$-_.+!*'(),
 279  *
 280  * But + is not safe because it's used to indicate a space; &= are only safe in
 281  * paths and not in queries (and we don't distinguish here); ' seems kind of
 282  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 283  * is reserved, we don't care.  So the list we unescape is:
 284  *
 285  * ;:@$!*(),/
 286  *
 287  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 288  * so no fancy : for IIS7.
 289  *
 290  * %2F in the page titles seems to fatally break for some reason.
 291  *
 292  * @param $s String:
 293  * @return string
 294 */
 295 function wfUrlencode( $s ) {
 296         static $needle;
 297         if ( is_null( $needle ) ) {
 298                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 299                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 300                         $needle[] = '%3A';
 301                 }
 302         }
 303
 304         $s = urlencode( $s );
 305         $s = str_ireplace(
 306                 $needle,
 307                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 308                 $s
 309         );
 310
 311         return $s;
 312 }
 313
 314 /**
 315  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 316  * "days=7&limit=100". Options in the first array override options in the second.
 317  * Options set to "" will not be output.
 318  *
 319  * @param $array1 Array ( String|Array )
 320  * @param $array2 Array ( String|Array )
 321  * @param $prefix String
 322  * @return String
 323  */
 324 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 325         if ( !is_null( $array2 ) ) {
 326                 $array1 = $array1 + $array2;
 327         }
 328
 329         $cgi = '';
 330         foreach ( $array1 as $key => $value ) {
 331                 if ( $value !== '' ) {
 332                         if ( $cgi != '' ) {
 333                                 $cgi .= '&';
 334                         }
 335                         if ( $prefix !== '' ) {
 336                                 $key = $prefix . "[$key]";
 337                         }
 338                         if ( is_array( $value ) ) {
 339                                 $firstTime = true;
 340                                 foreach ( $value as $k => $v ) {
 341                                         $cgi .= $firstTime ? '' : '&';
 342                                         if ( is_array( $v ) ) {
 343                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 344                                         } else {
 345                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 346                                         }
 347                                         $firstTime = false;
 348                                 }
 349                         } else {
 350                                 if ( is_object( $value ) ) {
 351                                         $value = $value->__toString();
 352                                 }
 353                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 354                         }
 355                 }
 356         }
 357         return $cgi;
 358 }
 359
 360 /**
 361  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 362  * its argument and returns the same string in array form.  This allows compa-
 363  * tibility with legacy functions that accept raw query strings instead of nice
 364  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 365  * valid query strings, or it will explode.
 366  *
 367  * @param $query String: query string
 368  * @return array Array version of input
 369  */
 370 function wfCgiToArray( $query ) {
 371         if ( isset( $query[0] ) && $query[0] == '?' ) {
 372                 $query = substr( $query, 1 );
 373         }
 374         $bits = explode( '&', $query );
 375         $ret = array();
 376         foreach ( $bits as $bit ) {
 377                 if ( $bit === '' ) {
 378                         continue;
 379                 }
 380                 list( $key, $value ) = explode( '=', $bit );
 381                 $key = urldecode( $key );
 382                 $value = urldecode( $value );
 383                 if ( strpos( $key, '[' ) !== false ) {
 384                         $keys = array_reverse( explode( '[', $key ) );
 385                         $key = array_pop( $keys );
 386                         $temp = $value;
 387                         foreach ( $keys as $k ) {
 388                                 $k = substr( $k, 0, -1 );
 389                                 $temp = array( $k => $temp );
 390                         }
 391                         if ( isset( $ret[$key] ) ) {
 392                                 $ret[$key] = array_merge( $ret[$key], $temp );
 393                         } else {
 394                                 $ret[$key] = $temp;
 395                         }
 396                 } else {
 397                         $ret[$key] = $value;
 398                 }
 399         }
 400         return $ret;
 401 }
 402
 403 /**
 404  * Append a query string to an existing URL, which may or may not already
 405  * have query string parameters already. If so, they will be combined.
 406  *
 407  * @param $url String
 408  * @param $query Mixed: string or associative array
 409  * @return string
 410  */
 411 function wfAppendQuery( $url, $query ) {
 412         if ( is_array( $query ) ) {
 413                 $query = wfArrayToCGI( $query );
 414         }
 415         if( $query != '' ) {
 416                 if( false === strpos( $url, '?' ) ) {
 417                         $url .= '?';
 418                 } else {
 419                         $url .= '&';
 420                 }
 421                 $url .= $query;
 422         }
 423         return $url;
 424 }
 425
 426 /**
 427  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 428  * is correct.
 429  *
 430  * @todo this won't work with current-path-relative URLs
 431  * like "subdir/foo.html", etc.
 432  *
 433  * @param $url String: either fully-qualified or a local path + query
 434  * @return string Fully-qualified URL
 435  */
 436 function wfExpandUrl( $url ) {
 437         global $wgServer;
 438         if( substr( $url, 0, 2 ) == '//' ) {
 439                 $bits = wfParseUrl( $wgServer );
 440                 $scheme = $bits && $bits['scheme'] !== '' ? $bits['scheme'] : 'http';
 441                 return $scheme . ':' . $url;
 442         } elseif( substr( $url, 0, 1 ) == '/' ) {
 443                 return $wgServer . $url;
 444         } else {
 445                 return $url;
 446         }
 447 }
 448
 449 /**
 450  * Returns a regular expression of url protocols
 451  *
 452  * @return String
 453  */
 454 function wfUrlProtocols() {
 455         global $wgUrlProtocols;
 456
 457         static $retval = null;
 458         if ( !is_null( $retval ) ) {
 459                 return $retval;
 460         }
 461
 462         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 463         // with LocalSettings files from 1.5
 464         if ( is_array( $wgUrlProtocols ) ) {
 465                 $protocols = array();
 466                 foreach ( $wgUrlProtocols as $protocol ) {
 467                         $protocols[] = preg_quote( $protocol, '/' );
 468                 }
 469
 470                 $retval = implode( '|', $protocols );
 471         } else {
 472                 $retval = $wgUrlProtocols;
 473         }
 474         return $retval;
 475 }
 476
 477 /**
 478  * parse_url() work-alike, but non-broken.  Differences:
 479  *
 480  * 1) Does not raise warnings on bad URLs (just returns false)
 481  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 482  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 483  *
 484  * @param $url String: a URL to parse
 485  * @return Array: bits of the URL in an associative array, per PHP docs
 486  */
 487 function wfParseUrl( $url ) {
 488         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 489
 490         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 491         // way to handle them is to just prepend 'http:' and strip the protocol out later
 492         $wasRelative = substr( $url, 0, 2 ) == '//';
 493         if ( $wasRelative ) {
 494                 $url = "http:$url";
 495         }
 496         wfSuppressWarnings();
 497         $bits = parse_url( $url );
 498         wfRestoreWarnings();
 499         if ( !$bits ) {
 500                 return false;
 501         }
 502
 503         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 504         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 505                 $bits['delimiter'] = '://';
 506         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 507                 $bits['delimiter'] = ':';
 508                 // parse_url detects for news: and mailto: the host part of an url as path
 509                 // We have to correct this wrong detection
 510                 if ( isset( $bits['path'] ) ) {
 511                         $bits['host'] = $bits['path'];
 512                         $bits['path'] = '';
 513                 }
 514         } else {
 515                 return false;
 516         }
 517
 518         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 519         if ( !isset( $bits['host'] ) ) {
 520                 $bits['host'] = '';
 521
 522                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 523                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 524                         $bits['path'] = '/' . $bits['path'];
 525                 }
 526         }
 527
 528         // If the URL was protocol-relative, fix scheme and delimiter
 529         if ( $wasRelative ) {
 530                 $bits['scheme'] = '';
 531                 $bits['delimiter'] = '//';
 532         }
 533         return $bits;
 534 }
 535
 536 /**
 537  * Make a URL index, appropriate for the el_index field of externallinks.
 538  *
 539  * @param $url String
 540  * @return String
 541  */
 542 function wfMakeUrlIndex( $url ) {
 543         $bits = wfParseUrl( $url );
 544
 545         // Reverse the labels in the hostname, convert to lower case
 546         // For emails reverse domainpart only
 547         if ( $bits['scheme'] == 'mailto' ) {
 548                 $mailparts = explode( '@', $bits['host'], 2 );
 549                 if ( count( $mailparts ) === 2 ) {
 550                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 551                 } else {
 552                         // No domain specified, don't mangle it
 553                         $domainpart = '';
 554                 }
 555                 $reversedHost = $domainpart . '@' . $mailparts[0];
 556         } else {
 557                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 558         }
 559         // Add an extra dot to the end
 560         // Why? Is it in wrong place in mailto links?
 561         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 562                 $reversedHost .= '.';
 563         }
 564         // Reconstruct the pseudo-URL
 565         $prot = $bits['scheme'];
 566         $index = $prot . $bits['delimiter'] . $reversedHost;
 567         // Leave out user and password. Add the port, path, query and fragment
 568         if ( isset( $bits['port'] ) ) {
 569                 $index .= ':' . $bits['port'];
 570         }
 571         if ( isset( $bits['path'] ) ) {
 572                 $index .= $bits['path'];
 573         } else {
 574                 $index .= '/';
 575         }
 576         if ( isset( $bits['query'] ) ) {
 577                 $index .= '?' . $bits['query'];
 578         }
 579         if ( isset( $bits['fragment'] ) ) {
 580                 $index .= '#' . $bits['fragment'];
 581         }
 582         return $index;
 583 }
 584
 585 /**
 586  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 587  * In normal operation this is a NOP.
 588  *
 589  * Controlling globals:
 590  * $wgDebugLogFile - points to the log file
 591  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 592  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 593  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 594  *
 595  * @param $text String
 596  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 597  */
 598 function wfDebug( $text, $logonly = false ) {
 599         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 600         global $wgDebugLogPrefix, $wgShowDebug;
 601
 602         static $cache = array(); // Cache of unoutputted messages
 603         $text = wfDebugTimer() . $text;
 604
 605         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 606                 return;
 607         }
 608
 609         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 610                 $cache[] = $text;
 611
 612                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 613                         // add the message and any cached messages to the output
 614                         array_map( array( $wgOut, 'debug' ), $cache );
 615                         $cache = array();
 616                 }
 617         }
 618         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 619                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 620                         # Strip unprintables; they can switch terminal modes when binary data
 621                         # gets dumped, which is pretty annoying.
 622                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 623                         $text = $wgDebugLogPrefix . $text;
 624                         wfErrorLog( $text, $wgDebugLogFile );
 625                 }
 626         }
 627 }
 628
 629 /**
 630  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 631  */
 632 function wfIsDebugRawPage() {
 633         static $cache;
 634         if ( $cache !== null ) {
 635                 return $cache;
 636         }
 637         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 638         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 639                 || (
 640                         isset( $_SERVER['SCRIPT_NAME'] )
 641                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 642                 ) )
 643         {
 644                 $cache = true;
 645         } else {
 646                 $cache = false;
 647         }
 648         return $cache;
 649 }
 650
 651 /**
 652  * Get microsecond timestamps for debug logs
 653  *
 654  * @return string
 655  */
 656 function wfDebugTimer() {
 657         global $wgDebugTimestamps;
 658         if ( !$wgDebugTimestamps ) {
 659                 return '';
 660         }
 661         static $start = null;
 662
 663         if ( $start === null ) {
 664                 $start = microtime( true );
 665                 $prefix = "\n$start";
 666         } else {
 667                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 668         }
 669
 670         return $prefix . '  ';
 671 }
 672
 673 /**
 674  * Send a line giving PHP memory usage.
 675  *
 676  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 677  */
 678 function wfDebugMem( $exact = false ) {
 679         $mem = memory_get_usage();
 680         if( !$exact ) {
 681                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 682         } else {
 683                 $mem .= ' bytes';
 684         }
 685         wfDebug( "Memory usage: $mem\n" );
 686 }
 687
 688 /**
 689  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 690  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 691  *
 692  * @param $logGroup String
 693  * @param $text String
 694  * @param $public Bool: whether to log the event in the public log if no private
 695  *                     log file is specified, (default true)
 696  */
 697 function wfDebugLog( $logGroup, $text, $public = true ) {
 698         global $wgDebugLogGroups, $wgShowHostnames;
 699         $text = trim( $text ) . "\n";
 700         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 701                 $time = wfTimestamp( TS_DB );
 702                 $wiki = wfWikiID();
 703                 if ( $wgShowHostnames ) {
 704                         $host = wfHostname();
 705                 } else {
 706                         $host = '';
 707                 }
 708                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 709                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 710                 }
 711         } elseif ( $public === true ) {
 712                 wfDebug( $text, true );
 713         }
 714 }
 715
 716 /**
 717  * Log for database errors
 718  *
 719  * @param $text String: database error message.
 720  */
 721 function wfLogDBError( $text ) {
 722         global $wgDBerrorLog, $wgDBname;
 723         if ( $wgDBerrorLog ) {
 724                 $host = trim(`hostname`);
 725                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 726                 wfErrorLog( $text, $wgDBerrorLog );
 727         }
 728 }
 729
 730 /**
 731  * Log to a file without getting "file size exceeded" signals.
 732  *
 733  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 734  * send lines to the specified port, prefixed by the specified prefix and a space.
 735  *
 736  * @param $text String
 737  * @param $file String filename
 738  */
 739 function wfErrorLog( $text, $file ) {
 740         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 741                 # Needs the sockets extension
 742                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 743                         // IPv6 bracketed host
 744                         $host = $m[2];
 745                         $port = intval( $m[3] );
 746                         $prefix = isset( $m[4] ) ? $m[4] : false;
 747                         $domain = AF_INET6;
 748                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 749                         $host = $m[2];
 750                         if ( !IP::isIPv4( $host ) ) {
 751                                 $host = gethostbyname( $host );
 752                         }
 753                         $port = intval( $m[3] );
 754                         $prefix = isset( $m[4] ) ? $m[4] : false;
 755                         $domain = AF_INET;
 756                 } else {
 757                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 758                 }
 759
 760                 // Clean it up for the multiplexer
 761                 if ( strval( $prefix ) !== '' ) {
 762                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 763
 764                         // Limit to 64KB
 765                         if ( strlen( $text ) > 65534 ) {
 766                                 $text = substr( $text, 0, 65534 );
 767                         }
 768
 769                         if ( substr( $text, -1 ) != "\n" ) {
 770                                 $text .= "\n";
 771                         }
 772                 } elseif ( strlen( $text ) > 65535 ) {
 773                         $text = substr( $text, 0, 65535 );
 774                 }
 775
 776                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 777                 if ( !$sock ) {
 778                         return;
 779                 }
 780                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 781                 socket_close( $sock );
 782         } else {
 783                 wfSuppressWarnings();
 784                 $exists = file_exists( $file );
 785                 $size = $exists ? filesize( $file ) : false;
 786                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 787                         file_put_contents( $file, $text, FILE_APPEND );
 788                 }
 789                 wfRestoreWarnings();
 790         }
 791 }
 792
 793 /**
 794  * @todo document
 795  */
 796 function wfLogProfilingData() {
 797         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 798         global $wgProfileLimit, $wgUser;
 799
 800         $profiler = Profiler::instance();
 801
 802         # Profiling must actually be enabled...
 803         if ( $profiler->isStub() ) {
 804                 return;
 805         }
 806
 807         // Get total page request time and only show pages that longer than
 808         // $wgProfileLimit time (default is 0)
 809         $now = wfTime();
 810         $elapsed = $now - $wgRequestTime;
 811         if ( $elapsed <= $wgProfileLimit ) {
 812                 return;
 813         }
 814
 815         $profiler->logData();
 816
 817         // Check whether this should be logged in the debug file.
 818         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 819                 return;
 820         }
 821
 822         $forward = '';
 823         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 824                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 825         }
 826         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 827                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 828         }
 829         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 830                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 831         }
 832         if ( $forward ) {
 833                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 834         }
 835         // Don't load $wgUser at this late stage just for statistics purposes
 836         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 837         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 838                 $forward .= ' anon';
 839         }
 840         $log = sprintf( "%s\t%04.3f\t%s\n",
 841                 gmdate( 'YmdHis' ), $elapsed,
 842                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 843
 844         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 845 }
 846
 847 /**
 848  * Check if the wiki read-only lock file is present. This can be used to lock
 849  * off editing functions, but doesn't guarantee that the database will not be
 850  * modified.
 851  *
 852  * @return bool
 853  */
 854 function wfReadOnly() {
 855         global $wgReadOnlyFile, $wgReadOnly;
 856
 857         if ( !is_null( $wgReadOnly ) ) {
 858                 return (bool)$wgReadOnly;
 859         }
 860         if ( $wgReadOnlyFile == '' ) {
 861                 return false;
 862         }
 863         // Set $wgReadOnly for faster access next time
 864         if ( is_file( $wgReadOnlyFile ) ) {
 865                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 866         } else {
 867                 $wgReadOnly = false;
 868         }
 869         return (bool)$wgReadOnly;
 870 }
 871
 872 function wfReadOnlyReason() {
 873         global $wgReadOnly;
 874         wfReadOnly();
 875         return $wgReadOnly;
 876 }
 877
 878 /**
 879  * Return a Language object from $langcode
 880  *
 881  * @param $langcode Mixed: either:
 882  *                  - a Language object
 883  *                  - code of the language to get the message for, if it is
 884  *                    a valid code create a language for that language, if
 885  *                    it is a string but not a valid code then make a basic
 886  *                    language object
 887  *                  - a boolean: if it's false then use the current users
 888  *                    language (as a fallback for the old parameter
 889  *                    functionality), or if it is true then use the wikis
 890  * @return Language object
 891  */
 892 function wfGetLangObj( $langcode = false ) {
 893         # Identify which language to get or create a language object for.
 894         # Using is_object here due to Stub objects.
 895         if( is_object( $langcode ) ) {
 896                 # Great, we already have the object (hopefully)!
 897                 return $langcode;
 898         }
 899
 900         global $wgContLang, $wgLanguageCode;
 901         if( $langcode === true || $langcode === $wgLanguageCode ) {
 902                 # $langcode is the language code of the wikis content language object.
 903                 # or it is a boolean and value is true
 904                 return $wgContLang;
 905         }
 906
 907         global $wgLang;
 908         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 909                 # $langcode is the language code of user language object.
 910                 # or it was a boolean and value is false
 911                 return $wgLang;
 912         }
 913
 914         $validCodes = array_keys( Language::getLanguageNames() );
 915         if( in_array( $langcode, $validCodes ) ) {
 916                 # $langcode corresponds to a valid language.
 917                 return Language::factory( $langcode );
 918         }
 919
 920         # $langcode is a string, but not a valid language code; use content language.
 921         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 922         return $wgContLang;
 923 }
 924
 925 /**
 926  * Old function when $wgBetterDirectionality existed
 927  * Removed in core, kept in extensions for backwards compat.
 928  *
 929  * @deprecated since 1.19
 930  * @return Language
 931  */
 932 function wfUILang() {
 933         global $wgLang;
 934         return $wgLang;
 935 }
 936
 937 /**
 938  * This is the new function for getting translated interface messages.
 939  * See the Message class for documentation how to use them.
 940  * The intention is that this function replaces all old wfMsg* functions.
 941  * @param $key \string Message key.
 942  * Varargs: normal message parameters.
 943  * @return Message
 944  * @since 1.17
 945  */
 946 function wfMessage( $key /*...*/) {
 947         $params = func_get_args();
 948         array_shift( $params );
 949         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 950                 $params = $params[0];
 951         }
 952         return new Message( $key, $params );
 953 }
 954
 955 /**
 956  * This function accepts multiple message keys and returns a message instance
 957  * for the first message which is non-empty. If all messages are empty then an
 958  * instance of the first message key is returned.
 959  * @param varargs: message keys
 960  * @return Message
 961  * @since 1.18
 962  */
 963 function wfMessageFallback( /*...*/ ) {
 964         $args = func_get_args();
 965         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 966 }
 967
 968 /**
 969  * Get a message from anywhere, for the current user language.
 970  *
 971  * Use wfMsgForContent() instead if the message should NOT
 972  * change depending on the user preferences.
 973  *
 974  * @param $key String: lookup key for the message, usually
 975  *    defined in languages/Language.php
 976  *
 977  * Parameters to the message, which can be used to insert variable text into
 978  * it, can be passed to this function in the following formats:
 979  * - One per argument, starting at the second parameter
 980  * - As an array in the second parameter
 981  * These are not shown in the function definition.
 982  *
 983  * @return String
 984  */
 985 function wfMsg( $key ) {
 986         $args = func_get_args();
 987         array_shift( $args );
 988         return wfMsgReal( $key, $args );
 989 }
 990
 991 /**
 992  * Same as above except doesn't transform the message
 993  *
 994  * @param $key String
 995  * @return String
 996  */
 997 function wfMsgNoTrans( $key ) {
 998         $args = func_get_args();
 999         array_shift( $args );
1000         return wfMsgReal( $key, $args, true, false, false );
1001 }
1002
1003 /**
1004  * Get a message from anywhere, for the current global language
1005  * set with $wgLanguageCode.
1006  *
1007  * Use this if the message should NOT change dependent on the
1008  * language set in the user's preferences. This is the case for
1009  * most text written into logs, as well as link targets (such as
1010  * the name of the copyright policy page). Link titles, on the
1011  * other hand, should be shown in the UI language.
1012  *
1013  * Note that MediaWiki allows users to change the user interface
1014  * language in their preferences, but a single installation
1015  * typically only contains content in one language.
1016  *
1017  * Be wary of this distinction: If you use wfMsg() where you should
1018  * use wfMsgForContent(), a user of the software may have to
1019  * customize potentially hundreds of messages in
1020  * order to, e.g., fix a link in every possible language.
1021  *
1022  * @param $key String: lookup key for the message, usually
1023  *     defined in languages/Language.php
1024  * @return String
1025  */
1026 function wfMsgForContent( $key ) {
1027         global $wgForceUIMsgAsContentMsg;
1028         $args = func_get_args();
1029         array_shift( $args );
1030         $forcontent = true;
1031         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1032                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1033         {
1034                 $forcontent = false;
1035         }
1036         return wfMsgReal( $key, $args, true, $forcontent );
1037 }
1038
1039 /**
1040  * Same as above except doesn't transform the message
1041  *
1042  * @param $key String
1043  * @return String
1044  */
1045 function wfMsgForContentNoTrans( $key ) {
1046         global $wgForceUIMsgAsContentMsg;
1047         $args = func_get_args();
1048         array_shift( $args );
1049         $forcontent = true;
1050         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1051                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1052         {
1053                 $forcontent = false;
1054         }
1055         return wfMsgReal( $key, $args, true, $forcontent, false );
1056 }
1057
1058 /**
1059  * Really get a message
1060  *
1061  * @param $key String: key to get.
1062  * @param $args
1063  * @param $useDB Boolean
1064  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1065  * @param $transform Boolean: Whether or not to transform the message.
1066  * @return String: the requested message.
1067  */
1068 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1069         wfProfileIn( __METHOD__ );
1070         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1071         $message = wfMsgReplaceArgs( $message, $args );
1072         wfProfileOut( __METHOD__ );
1073         return $message;
1074 }
1075
1076 /**
1077  * Fetch a message string value, but don't replace any keys yet.
1078  *
1079  * @param $key String
1080  * @param $useDB Bool
1081  * @param $langCode String: Code of the language to get the message for, or
1082  *                  behaves as a content language switch if it is a boolean.
1083  * @param $transform Boolean: whether to parse magic words, etc.
1084  * @return string
1085  */
1086 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1087         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1088
1089         $cache = MessageCache::singleton();
1090         $message = $cache->get( $key, $useDB, $langCode );
1091         if( $message === false ) {
1092                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1093         } elseif ( $transform ) {
1094                 $message = $cache->transform( $message );
1095         }
1096         return $message;
1097 }
1098
1099 /**
1100  * Replace message parameter keys on the given formatted output.
1101  *
1102  * @param $message String
1103  * @param $args Array
1104  * @return string
1105  * @private
1106  */
1107 function wfMsgReplaceArgs( $message, $args ) {
1108         # Fix windows line-endings
1109         # Some messages are split with explode("\n", $msg)
1110         $message = str_replace( "\r", '', $message );
1111
1112         // Replace arguments
1113         if ( count( $args ) ) {
1114                 if ( is_array( $args[0] ) ) {
1115                         $args = array_values( $args[0] );
1116                 }
1117                 $replacementKeys = array();
1118                 foreach( $args as $n => $param ) {
1119                         $replacementKeys['$' . ( $n + 1 )] = $param;
1120                 }
1121                 $message = strtr( $message, $replacementKeys );
1122         }
1123
1124         return $message;
1125 }
1126
1127 /**
1128  * Return an HTML-escaped version of a message.
1129  * Parameter replacements, if any, are done *after* the HTML-escaping,
1130  * so parameters may contain HTML (eg links or form controls). Be sure
1131  * to pre-escape them if you really do want plaintext, or just wrap
1132  * the whole thing in htmlspecialchars().
1133  *
1134  * @param $key String
1135  * @param string ... parameters
1136  * @return string
1137  */
1138 function wfMsgHtml( $key ) {
1139         $args = func_get_args();
1140         array_shift( $args );
1141         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1142 }
1143
1144 /**
1145  * Return an HTML version of message
1146  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1147  * so parameters may contain HTML (eg links or form controls). Be sure
1148  * to pre-escape them if you really do want plaintext, or just wrap
1149  * the whole thing in htmlspecialchars().
1150  *
1151  * @param $key String
1152  * @param string ... parameters
1153  * @return string
1154  */
1155 function wfMsgWikiHtml( $key ) {
1156         $args = func_get_args();
1157         array_shift( $args );
1158         return wfMsgReplaceArgs(
1159                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null, /* can't be set to false */ true )->getText(),
1160                 $args );
1161 }
1162
1163 /**
1164  * Returns message in the requested format
1165  * @param $key String: key of the message
1166  * @param $options Array: processing rules. Can take the following options:
1167  *   <i>parse</i>: parses wikitext to HTML
1168  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1169  *       p's added by parser or tidy
1170  *   <i>escape</i>: filters message through htmlspecialchars
1171  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1172  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1173  *   <i>parsemag</i>: transform the message using magic phrases
1174  *   <i>content</i>: fetch message for content language instead of interface
1175  * Also can accept a single associative argument, of the form 'language' => 'xx':
1176  *   <i>language</i>: Language object or language code to fetch message for
1177  *       (overriden by <i>content</i>).
1178  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1179  *
1180  * @return String
1181  */
1182 function wfMsgExt( $key, $options ) {
1183         $args = func_get_args();
1184         array_shift( $args );
1185         array_shift( $args );
1186         $options = (array)$options;
1187
1188         foreach( $options as $arrayKey => $option ) {
1189                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1190                         # An unknown index, neither numeric nor "language"
1191                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1192                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1193                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1194                 'replaceafter', 'parsemag', 'content' ) ) ) {
1195                         # A numeric index with unknown value
1196                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1197                 }
1198         }
1199
1200         if( in_array( 'content', $options, true ) ) {
1201                 $forContent = true;
1202                 $langCode = true;
1203                 $langCodeObj = null;
1204         } elseif( array_key_exists( 'language', $options ) ) {
1205                 $forContent = false;
1206                 $langCode = wfGetLangObj( $options['language'] );
1207                 $langCodeObj = $langCode;
1208         } else {
1209                 $forContent = false;
1210                 $langCode = false;
1211                 $langCodeObj = null;
1212         }
1213
1214         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1215
1216         if( !in_array( 'replaceafter', $options, true ) ) {
1217                 $string = wfMsgReplaceArgs( $string, $args );
1218         }
1219
1220         $messageCache = MessageCache::singleton();
1221         if( in_array( 'parse', $options, true ) ) {
1222                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1223         } elseif ( in_array( 'parseinline', $options, true ) ) {
1224                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1225                 $m = array();
1226                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1227                         $string = $m[1];
1228                 }
1229         } elseif ( in_array( 'parsemag', $options, true ) ) {
1230                 $string = $messageCache->transform( $string,
1231                                 !$forContent, $langCodeObj );
1232         }
1233
1234         if ( in_array( 'escape', $options, true ) ) {
1235                 $string = htmlspecialchars ( $string );
1236         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1237                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1238         }
1239
1240         if( in_array( 'replaceafter', $options, true ) ) {
1241                 $string = wfMsgReplaceArgs( $string, $args );
1242         }
1243
1244         return $string;
1245 }
1246
1247 /**
1248  * Since wfMsg() and co suck, they don't return false if the message key they
1249  * looked up didn't exist but a XHTML string, this function checks for the
1250  * nonexistance of messages by checking the MessageCache::get() result directly.
1251  *
1252  * @param $key      String: the message key looked up
1253  * @return Boolean True if the message *doesn't* exist.
1254  */
1255 function wfEmptyMsg( $key ) {
1256         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1257 }
1258
1259 /**
1260  * Throw a debugging exception. This function previously once exited the process,
1261  * but now throws an exception instead, with similar results.
1262  *
1263  * @param $msg String: message shown when dieing.
1264  */
1265 function wfDebugDieBacktrace( $msg = '' ) {
1266         throw new MWException( $msg );
1267 }
1268
1269 /**
1270  * Fetch server name for use in error reporting etc.
1271  * Use real server name if available, so we know which machine
1272  * in a server farm generated the current page.
1273  *
1274  * @return string
1275  */
1276 function wfHostname() {
1277         static $host;
1278         if ( is_null( $host ) ) {
1279                 if ( function_exists( 'posix_uname' ) ) {
1280                         // This function not present on Windows
1281                         $uname = posix_uname();
1282                 } else {
1283                         $uname = false;
1284                 }
1285                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1286                         $host = $uname['nodename'];
1287                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1288                         # Windows computer name
1289                         $host = getenv( 'COMPUTERNAME' );
1290                 } else {
1291                         # This may be a virtual server.
1292                         $host = $_SERVER['SERVER_NAME'];
1293                 }
1294         }
1295         return $host;
1296 }
1297
1298 /**
1299  * Returns a HTML comment with the elapsed time since request.
1300  * This method has no side effects.
1301  *
1302  * @return string
1303  */
1304 function wfReportTime() {
1305         global $wgRequestTime, $wgShowHostnames;
1306
1307         $now = wfTime();
1308         $elapsed = $now - $wgRequestTime;
1309
1310         return $wgShowHostnames
1311                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1312                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1313 }
1314
1315 /**
1316  * Safety wrapper for debug_backtrace().
1317  *
1318  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1319  * murky circumstances, which may be triggered in part by stub objects
1320  * or other fancy talkin'.
1321  *
1322  * Will return an empty array if Zend Optimizer is detected or if
1323  * debug_backtrace is disabled, otherwise the output from
1324  * debug_backtrace() (trimmed).
1325  *
1326  * @return array of backtrace information
1327  */
1328 function wfDebugBacktrace( $limit = 0 ) {
1329         static $disabled = null;
1330
1331         if( extension_loaded( 'Zend Optimizer' ) ) {
1332                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1333                 return array();
1334         }
1335
1336         if ( is_null( $disabled ) ) {
1337                 $disabled = false;
1338                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1339                 $functions = array_map( 'trim', $functions );
1340                 $functions = array_map( 'strtolower', $functions );
1341                 if ( in_array( 'debug_backtrace', $functions ) ) {
1342                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1343                         $disabled = true;
1344                 }
1345         }
1346         if ( $disabled ) {
1347                 return array();
1348         }
1349
1350         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1351                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1352         } else {
1353                 return array_slice( debug_backtrace(), 1 );
1354         }
1355 }
1356
1357 /**
1358  * Get a debug backtrace as a string
1359  *
1360  * @return string
1361  */
1362 function wfBacktrace() {
1363         global $wgCommandLineMode;
1364
1365         if ( $wgCommandLineMode ) {
1366                 $msg = '';
1367         } else {
1368                 $msg = "<ul>\n";
1369         }
1370         $backtrace = wfDebugBacktrace();
1371         foreach( $backtrace as $call ) {
1372                 if( isset( $call['file'] ) ) {
1373                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1374                         $file = $f[count( $f ) - 1];
1375                 } else {
1376                         $file = '-';
1377                 }
1378                 if( isset( $call['line'] ) ) {
1379                         $line = $call['line'];
1380                 } else {
1381                         $line = '-';
1382                 }
1383                 if ( $wgCommandLineMode ) {
1384                         $msg .= "$file line $line calls ";
1385                 } else {
1386                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1387                 }
1388                 if( !empty( $call['class'] ) ) {
1389                         $msg .= $call['class'] . $call['type'];
1390                 }
1391                 $msg .= $call['function'] . '()';
1392
1393                 if ( $wgCommandLineMode ) {
1394                         $msg .= "\n";
1395                 } else {
1396                         $msg .= "</li>\n";
1397                 }
1398         }
1399         if ( $wgCommandLineMode ) {
1400                 $msg .= "\n";
1401         } else {
1402                 $msg .= "</ul>\n";
1403         }
1404
1405         return $msg;
1406 }
1407
1408 /**
1409  * Get the name of the function which called this function
1410  *
1411  * @param $level Int
1412  * @return Bool|string
1413  */
1414 function wfGetCaller( $level = 2 ) {
1415         $backtrace = wfDebugBacktrace( $level );
1416         if ( isset( $backtrace[$level] ) ) {
1417                 return wfFormatStackFrame( $backtrace[$level] );
1418         } else {
1419                 $caller = 'unknown';
1420         }
1421         return $caller;
1422 }
1423
1424 /**
1425  * Return a string consisting of callers in the stack. Useful sometimes
1426  * for profiling specific points.
1427  *
1428  * @param $limit The maximum depth of the stack frame to return, or false for
1429  *               the entire stack.
1430  * @return String
1431  */
1432 function wfGetAllCallers( $limit = 3 ) {
1433         $trace = array_reverse( wfDebugBacktrace() );
1434         if ( !$limit || $limit > count( $trace ) - 1 ) {
1435                 $limit = count( $trace ) - 1;
1436         }
1437         $trace = array_slice( $trace, -$limit - 1, $limit );
1438         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1439 }
1440
1441 /**
1442  * Return a string representation of frame
1443  *
1444  * @param $frame Array
1445  * @return Bool
1446  */
1447 function wfFormatStackFrame( $frame ) {
1448         return isset( $frame['class'] ) ?
1449                 $frame['class'] . '::' . $frame['function'] :
1450                 $frame['function'];
1451 }
1452
1453
1454 /* Some generic result counters, pulled out of SearchEngine */
1455
1456
1457 /**
1458  * @todo document
1459  *
1460  * @param $offset Int
1461  * @param $limit Int
1462  * @return String
1463  */
1464 function wfShowingResults( $offset, $limit ) {
1465         global $wgLang;
1466         return wfMsgExt(
1467                 'showingresults',
1468                 array( 'parseinline' ),
1469                 $wgLang->formatNum( $limit ),
1470                 $wgLang->formatNum( $offset + 1 )
1471         );
1472 }
1473
1474 /**
1475  * Generate (prev x| next x) (20|50|100...) type links for paging
1476  *
1477  * @param $offset String
1478  * @param $limit Integer
1479  * @param $link String
1480  * @param $query String: optional URL query parameter string
1481  * @param $atend Bool: optional param for specified if this is the last page
1482  * @return String
1483  */
1484 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1485         global $wgLang;
1486         $fmtLimit = $wgLang->formatNum( $limit );
1487         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1488         # Get prev/next link display text
1489         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1490         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1491         # Get prev/next link title text
1492         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1493         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1494         # Fetch the title object
1495         if( is_object( $link ) ) {
1496                 $title =& $link;
1497         } else {
1498                 $title = Title::newFromText( $link );
1499                 if( is_null( $title ) ) {
1500                         return false;
1501                 }
1502         }
1503         # Make 'previous' link
1504         if( 0 != $offset ) {
1505                 $po = $offset - $limit;
1506                 $po = max( $po, 0 );
1507                 $q = "limit={$limit}&offset={$po}";
1508                 if( $query != '' ) {
1509                         $q .= '&' . $query;
1510                 }
1511                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1512         } else {
1513                 $plink = $prev;
1514         }
1515         # Make 'next' link
1516         $no = $offset + $limit;
1517         $q = "limit={$limit}&offset={$no}";
1518         if( $query != '' ) {
1519                 $q .= '&' . $query;
1520         }
1521         if( $atend ) {
1522                 $nlink = $next;
1523         } else {
1524                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1525         }
1526         # Make links to set number of items per page
1527         $nums = $wgLang->pipeList( array(
1528                 wfNumLink( $offset, 20, $title, $query ),
1529                 wfNumLink( $offset, 50, $title, $query ),
1530                 wfNumLink( $offset, 100, $title, $query ),
1531                 wfNumLink( $offset, 250, $title, $query ),
1532                 wfNumLink( $offset, 500, $title, $query )
1533         ) );
1534         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1535 }
1536
1537 /**
1538  * Generate links for (20|50|100...) items-per-page links
1539  *
1540  * @param $offset String
1541  * @param $limit Integer
1542  * @param $title Title
1543  * @param $query String: optional URL query parameter string
1544  */
1545 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1546         global $wgLang;
1547         if( $query == '' ) {
1548                 $q = '';
1549         } else {
1550                 $q = $query.'&';
1551         }
1552         $q .= "limit={$limit}&offset={$offset}";
1553         $fmtLimit = $wgLang->formatNum( $limit );
1554         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1555         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1556         return $s;
1557 }
1558
1559 /**
1560  * @todo document
1561  * @todo FIXME: We may want to blacklist some broken browsers
1562  *
1563  * @param $force Bool
1564  * @return bool Whereas client accept gzip compression
1565  */
1566 function wfClientAcceptsGzip( $force = false ) {
1567         static $result = null;
1568         if ( $result === null || $force ) {
1569                 $result = false;
1570                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1571                         # @todo FIXME: We may want to blacklist some broken browsers
1572                         $m = array();
1573                         if( preg_match(
1574                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1575                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1576                                 $m )
1577                         )
1578                         {
1579                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1580                                         $result = false;
1581                                         return $result;
1582                                 }
1583                                 wfDebug( " accepts gzip\n" );
1584                                 $result = true;
1585                         }
1586                 }
1587         }
1588         return $result;
1589 }
1590
1591 /**
1592  * Obtain the offset and limit values from the request string;
1593  * used in special pages
1594  *
1595  * @param $deflimit Int default limit if none supplied
1596  * @param $optionname String Name of a user preference to check against
1597  * @return array
1598  *
1599  */
1600 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1601         global $wgRequest;
1602         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1603 }
1604
1605 /**
1606  * Escapes the given text so that it may be output using addWikiText()
1607  * without any linking, formatting, etc. making its way through. This
1608  * is achieved by substituting certain characters with HTML entities.
1609  * As required by the callers, <nowiki> is not used.
1610  *
1611  * @param $text String: text to be escaped
1612  * @return String
1613  */
1614 function wfEscapeWikiText( $text ) {
1615         $text = strtr( "\n$text", array(
1616                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1617                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1618                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1619                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1620                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1621                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1622         ) );
1623         return substr( $text, 1 );
1624 }
1625
1626 /**
1627  * Get the current unix timetstamp with microseconds.  Useful for profiling
1628  * @return Float
1629  */
1630 function wfTime() {
1631         return microtime( true );
1632 }
1633
1634 /**
1635  * Sets dest to source and returns the original value of dest
1636  * If source is NULL, it just returns the value, it doesn't set the variable
1637  * If force is true, it will set the value even if source is NULL
1638  *
1639  * @param $dest Mixed
1640  * @param $source Mixed
1641  * @param $force Bool
1642  * @return Mixed
1643  */
1644 function wfSetVar( &$dest, $source, $force = false ) {
1645         $temp = $dest;
1646         if ( !is_null( $source ) || $force ) {
1647                 $dest = $source;
1648         }
1649         return $temp;
1650 }
1651
1652 /**
1653  * As for wfSetVar except setting a bit
1654  *
1655  * @param $dest Int
1656  * @param $bit Int
1657  * @param $state Bool
1658  */
1659 function wfSetBit( &$dest, $bit, $state = true ) {
1660         $temp = (bool)( $dest & $bit );
1661         if ( !is_null( $state ) ) {
1662                 if ( $state ) {
1663                         $dest |= $bit;
1664                 } else {
1665                         $dest &= ~$bit;
1666                 }
1667         }
1668         return $temp;
1669 }
1670
1671 /**
1672  * Windows-compatible version of escapeshellarg()
1673  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1674  * function puts single quotes in regardless of OS.
1675  *
1676  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1677  * earlier distro releases of PHP)
1678  *
1679  * @param varargs
1680  * @return String
1681  */
1682 function wfEscapeShellArg( ) {
1683         wfInitShellLocale();
1684
1685         $args = func_get_args();
1686         $first = true;
1687         $retVal = '';
1688         foreach ( $args as $arg ) {
1689                 if ( !$first ) {
1690                         $retVal .= ' ';
1691                 } else {
1692                         $first = false;
1693                 }
1694
1695                 if ( wfIsWindows() ) {
1696                         // Escaping for an MSVC-style command line parser and CMD.EXE
1697                         // Refs:
1698                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1699                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1700                         //  * Bug #13518
1701                         //  * CR r63214
1702                         // Double the backslashes before any double quotes. Escape the double quotes.
1703                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1704                         $arg = '';
1705                         $iteration = 0;
1706                         foreach ( $tokens as $token ) {
1707                                 if ( $iteration % 2 == 1 ) {
1708                                         // Delimiter, a double quote preceded by zero or more slashes
1709                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1710                                 } elseif ( $iteration % 4 == 2 ) {
1711                                         // ^ in $token will be outside quotes, need to be escaped
1712                                         $arg .= str_replace( '^', '^^', $token );
1713                                 } else { // $iteration % 4 == 0
1714                                         // ^ in $token will appear inside double quotes, so leave as is
1715                                         $arg .= $token;
1716                                 }
1717                                 $iteration++;
1718                         }
1719                         // Double the backslashes before the end of the string, because
1720                         // we will soon add a quote
1721                         $m = array();
1722                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1723                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1724                         }
1725
1726                         // Add surrounding quotes
1727                         $retVal .= '"' . $arg . '"';
1728                 } else {
1729                         $retVal .= escapeshellarg( $arg );
1730                 }
1731         }
1732         return $retVal;
1733 }
1734
1735 /**
1736  * wfMerge attempts to merge differences between three texts.
1737  * Returns true for a clean merge and false for failure or a conflict.
1738  *
1739  * @param $old String
1740  * @param $mine String
1741  * @param $yours String
1742  * @param $result String
1743  * @return Bool
1744  */
1745 function wfMerge( $old, $mine, $yours, &$result ) {
1746         global $wgDiff3;
1747
1748         # This check may also protect against code injection in
1749         # case of broken installations.
1750         wfSuppressWarnings();
1751         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1752         wfRestoreWarnings();
1753
1754         if( !$haveDiff3 ) {
1755                 wfDebug( "diff3 not found\n" );
1756                 return false;
1757         }
1758
1759         # Make temporary files
1760         $td = wfTempDir();
1761         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1762         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1763         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1764
1765         fwrite( $oldtextFile, $old );
1766         fclose( $oldtextFile );
1767         fwrite( $mytextFile, $mine );
1768         fclose( $mytextFile );
1769         fwrite( $yourtextFile, $yours );
1770         fclose( $yourtextFile );
1771
1772         # Check for a conflict
1773         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1774                 wfEscapeShellArg( $mytextName ) . ' ' .
1775                 wfEscapeShellArg( $oldtextName ) . ' ' .
1776                 wfEscapeShellArg( $yourtextName );
1777         $handle = popen( $cmd, 'r' );
1778
1779         if( fgets( $handle, 1024 ) ) {
1780                 $conflict = true;
1781         } else {
1782                 $conflict = false;
1783         }
1784         pclose( $handle );
1785
1786         # Merge differences
1787         $cmd = $wgDiff3 . ' -a -e --merge ' .
1788                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1789         $handle = popen( $cmd, 'r' );
1790         $result = '';
1791         do {
1792                 $data = fread( $handle, 8192 );
1793                 if ( strlen( $data ) == 0 ) {
1794                         break;
1795                 }
1796                 $result .= $data;
1797         } while ( true );
1798         pclose( $handle );
1799         unlink( $mytextName );
1800         unlink( $oldtextName );
1801         unlink( $yourtextName );
1802
1803         if ( $result === '' && $old !== '' && !$conflict ) {
1804                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1805                 $conflict = true;
1806         }
1807         return !$conflict;
1808 }
1809
1810 /**
1811  * Returns unified plain-text diff of two texts.
1812  * Useful for machine processing of diffs.
1813  *
1814  * @param $before String: the text before the changes.
1815  * @param $after String: the text after the changes.
1816  * @param $params String: command-line options for the diff command.
1817  * @return String: unified diff of $before and $after
1818  */
1819 function wfDiff( $before, $after, $params = '-u' ) {
1820         if ( $before == $after ) {
1821                 return '';
1822         }
1823
1824         global $wgDiff;
1825         wfSuppressWarnings();
1826         $haveDiff = $wgDiff && file_exists( $wgDiff );
1827         wfRestoreWarnings();
1828
1829         # This check may also protect against code injection in
1830         # case of broken installations.
1831         if( !$haveDiff ) {
1832                 wfDebug( "diff executable not found\n" );
1833                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1834                 $format = new UnifiedDiffFormatter();
1835                 return $format->format( $diffs );
1836         }
1837
1838         # Make temporary files
1839         $td = wfTempDir();
1840         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1841         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1842
1843         fwrite( $oldtextFile, $before );
1844         fclose( $oldtextFile );
1845         fwrite( $newtextFile, $after );
1846         fclose( $newtextFile );
1847
1848         // Get the diff of the two files
1849         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1850
1851         $h = popen( $cmd, 'r' );
1852
1853         $diff = '';
1854
1855         do {
1856                 $data = fread( $h, 8192 );
1857                 if ( strlen( $data ) == 0 ) {
1858                         break;
1859                 }
1860                 $diff .= $data;
1861         } while ( true );
1862
1863         // Clean up
1864         pclose( $h );
1865         unlink( $oldtextName );
1866         unlink( $newtextName );
1867
1868         // Kill the --- and +++ lines. They're not useful.
1869         $diff_lines = explode( "\n", $diff );
1870         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1871                 unset( $diff_lines[0] );
1872         }
1873         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1874                 unset( $diff_lines[1] );
1875         }
1876
1877         $diff = implode( "\n", $diff_lines );
1878
1879         return $diff;
1880 }
1881
1882 /**
1883  * A wrapper around the PHP function var_export().
1884  * Either print it or add it to the regular output ($wgOut).
1885  *
1886  * @param $var A PHP variable to dump.
1887  */
1888 function wfVarDump( $var ) {
1889         global $wgOut;
1890         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1891         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1892                 print $s;
1893         } else {
1894                 $wgOut->addHTML( $s );
1895         }
1896 }
1897
1898 /**
1899  * Provide a simple HTTP error.
1900  *
1901  * @param $code Int|String
1902  * @param $label String
1903  * @param $desc String
1904  */
1905 function wfHttpError( $code, $label, $desc ) {
1906         global $wgOut;
1907         $wgOut->disable();
1908         header( "HTTP/1.0 $code $label" );
1909         header( "Status: $code $label" );
1910         $wgOut->sendCacheControl();
1911
1912         header( 'Content-type: text/html; charset=utf-8' );
1913         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1914                 '<html><head><title>' .
1915                 htmlspecialchars( $label ) .
1916                 '</title></head><body><h1>' .
1917                 htmlspecialchars( $label ) .
1918                 '</h1><p>' .
1919                 nl2br( htmlspecialchars( $desc ) ) .
1920                 "</p></body></html>\n";
1921 }
1922
1923 /**
1924  * Clear away any user-level output buffers, discarding contents.
1925  *
1926  * Suitable for 'starting afresh', for instance when streaming
1927  * relatively large amounts of data without buffering, or wanting to
1928  * output image files without ob_gzhandler's compression.
1929  *
1930  * The optional $resetGzipEncoding parameter controls suppression of
1931  * the Content-Encoding header sent by ob_gzhandler; by default it
1932  * is left. See comments for wfClearOutputBuffers() for why it would
1933  * be used.
1934  *
1935  * Note that some PHP configuration options may add output buffer
1936  * layers which cannot be removed; these are left in place.
1937  *
1938  * @param $resetGzipEncoding Bool
1939  */
1940 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1941         if( $resetGzipEncoding ) {
1942                 // Suppress Content-Encoding and Content-Length
1943                 // headers from 1.10+s wfOutputHandler
1944                 global $wgDisableOutputCompression;
1945                 $wgDisableOutputCompression = true;
1946         }
1947         while( $status = ob_get_status() ) {
1948                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1949                         // Probably from zlib.output_compression or other
1950                         // PHP-internal setting which can't be removed.
1951                         //
1952                         // Give up, and hope the result doesn't break
1953                         // output behavior.
1954                         break;
1955                 }
1956                 if( !ob_end_clean() ) {
1957                         // Could not remove output buffer handler; abort now
1958                         // to avoid getting in some kind of infinite loop.
1959                         break;
1960                 }
1961                 if( $resetGzipEncoding ) {
1962                         if( $status['name'] == 'ob_gzhandler' ) {
1963                                 // Reset the 'Content-Encoding' field set by this handler
1964                                 // so we can start fresh.
1965                                 if ( function_exists( 'header_remove' ) ) {
1966                                         // Available since PHP 5.3.0
1967                                         header_remove( 'Content-Encoding' );
1968                                 } else {
1969                                         // We need to provide a valid content-coding. See bug 28069
1970                                         header( 'Content-Encoding: identity' );
1971                                 }
1972                                 break;
1973                         }
1974                 }
1975         }
1976 }
1977
1978 /**
1979  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1980  *
1981  * Clear away output buffers, but keep the Content-Encoding header
1982  * produced by ob_gzhandler, if any.
1983  *
1984  * This should be used for HTTP 304 responses, where you need to
1985  * preserve the Content-Encoding header of the real result, but
1986  * also need to suppress the output of ob_gzhandler to keep to spec
1987  * and avoid breaking Firefox in rare cases where the headers and
1988  * body are broken over two packets.
1989  */
1990 function wfClearOutputBuffers() {
1991         wfResetOutputBuffers( false );
1992 }
1993
1994 /**
1995  * Converts an Accept-* header into an array mapping string values to quality
1996  * factors
1997  *
1998  * @param $accept String
1999  * @param $def String default
2000  * @return Array
2001  */
2002 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2003         # No arg means accept anything (per HTTP spec)
2004         if( !$accept ) {
2005                 return array( $def => 1.0 );
2006         }
2007
2008         $prefs = array();
2009
2010         $parts = explode( ',', $accept );
2011
2012         foreach( $parts as $part ) {
2013                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2014                 $values = explode( ';', trim( $part ) );
2015                 $match = array();
2016                 if ( count( $values ) == 1 ) {
2017                         $prefs[$values[0]] = 1.0;
2018                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2019                         $prefs[$values[0]] = floatval( $match[1] );
2020                 }
2021         }
2022
2023         return $prefs;
2024 }
2025
2026 /**
2027  * Checks if a given MIME type matches any of the keys in the given
2028  * array. Basic wildcards are accepted in the array keys.
2029  *
2030  * Returns the matching MIME type (or wildcard) if a match, otherwise
2031  * NULL if no match.
2032  *
2033  * @param $type String
2034  * @param $avail Array
2035  * @return string
2036  * @private
2037  */
2038 function mimeTypeMatch( $type, $avail ) {
2039         if( array_key_exists( $type, $avail ) ) {
2040                 return $type;
2041         } else {
2042                 $parts = explode( '/', $type );
2043                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2044                         return $parts[0] . '/*';
2045                 } elseif( array_key_exists( '*/*', $avail ) ) {
2046                         return '*/*';
2047                 } else {
2048                         return null;
2049                 }
2050         }
2051 }
2052
2053 /**
2054  * Returns the 'best' match between a client's requested internet media types
2055  * and the server's list of available types. Each list should be an associative
2056  * array of type to preference (preference is a float between 0.0 and 1.0).
2057  * Wildcards in the types are acceptable.
2058  *
2059  * @param $cprefs Array: client's acceptable type list
2060  * @param $sprefs Array: server's offered types
2061  * @return string
2062  *
2063  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2064  * XXX: generalize to negotiate other stuff
2065  */
2066 function wfNegotiateType( $cprefs, $sprefs ) {
2067         $combine = array();
2068
2069         foreach( array_keys($sprefs) as $type ) {
2070                 $parts = explode( '/', $type );
2071                 if( $parts[1] != '*' ) {
2072                         $ckey = mimeTypeMatch( $type, $cprefs );
2073                         if( $ckey ) {
2074                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2075                         }
2076                 }
2077         }
2078
2079         foreach( array_keys( $cprefs ) as $type ) {
2080                 $parts = explode( '/', $type );
2081                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2082                         $skey = mimeTypeMatch( $type, $sprefs );
2083                         if( $skey ) {
2084                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2085                         }
2086                 }
2087         }
2088
2089         $bestq = 0;
2090         $besttype = null;
2091
2092         foreach( array_keys( $combine ) as $type ) {
2093                 if( $combine[$type] > $bestq ) {
2094                         $besttype = $type;
2095                         $bestq = $combine[$type];
2096                 }
2097         }
2098
2099         return $besttype;
2100 }
2101
2102 /**
2103  * Reference-counted warning suppression
2104  *
2105  * @param $end Bool
2106  */
2107 function wfSuppressWarnings( $end = false ) {
2108         static $suppressCount = 0;
2109         static $originalLevel = false;
2110
2111         if ( $end ) {
2112                 if ( $suppressCount ) {
2113                         --$suppressCount;
2114                         if ( !$suppressCount ) {
2115                                 error_reporting( $originalLevel );
2116                         }
2117                 }
2118         } else {
2119                 if ( !$suppressCount ) {
2120                         // E_DEPRECATED is undefined in PHP 5.2
2121                         if( !defined( 'E_DEPRECATED' ) ){
2122                                 define( 'E_DEPRECATED', 8192 );
2123                         }
2124                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2125                 }
2126                 ++$suppressCount;
2127         }
2128 }
2129
2130 /**
2131  * Restore error level to previous value
2132  */
2133 function wfRestoreWarnings() {
2134         wfSuppressWarnings( true );
2135 }
2136
2137 # Autodetect, convert and provide timestamps of various types
2138
2139 /**
2140  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2141  */
2142 define( 'TS_UNIX', 0 );
2143
2144 /**
2145  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2146  */
2147 define( 'TS_MW', 1 );
2148
2149 /**
2150  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2151  */
2152 define( 'TS_DB', 2 );
2153
2154 /**
2155  * RFC 2822 format, for E-mail and HTTP headers
2156  */
2157 define( 'TS_RFC2822', 3 );
2158
2159 /**
2160  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2161  *
2162  * This is used by Special:Export
2163  */
2164 define( 'TS_ISO_8601', 4 );
2165
2166 /**
2167  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2168  *
2169  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2170  *       DateTime tag and page 36 for the DateTimeOriginal and
2171  *       DateTimeDigitized tags.
2172  */
2173 define( 'TS_EXIF', 5 );
2174
2175 /**
2176  * Oracle format time.
2177  */
2178 define( 'TS_ORACLE', 6 );
2179
2180 /**
2181  * Postgres format time.
2182  */
2183 define( 'TS_POSTGRES', 7 );
2184
2185 /**
2186  * DB2 format time
2187  */
2188 define( 'TS_DB2', 8 );
2189
2190 /**
2191  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2192  */
2193 define( 'TS_ISO_8601_BASIC', 9 );
2194
2195 /**
2196  * Get a timestamp string in one of various formats
2197  *
2198  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2199  *                    function will autodetect which format is supplied and act
2200  *                    accordingly.
2201  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2202  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2203  */
2204 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2205         $uts = 0;
2206         $da = array();
2207         $strtime = '';
2208
2209         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2210                 $uts = time();
2211                 $strtime = "@$uts";
2212         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2213                 # TS_DB
2214         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2215                 # TS_EXIF
2216         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2217                 # TS_MW
2218         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2219                 # TS_UNIX
2220                 $uts = $ts;
2221                 $strtime = "@$ts"; // Undocumented?
2222         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2223                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2224                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2225                                 str_replace( '+00:00', 'UTC', $ts ) );
2226         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2227                 # TS_ISO_8601
2228         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2229                 #TS_ISO_8601_BASIC
2230         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2231                 # TS_POSTGRES
2232         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2233                 # TS_POSTGRES
2234         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2235                 # TS_DB2
2236         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2237                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2238                                                         '[ \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
2239                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2240                 # The regex is a superset of rfc2822 for readability
2241                 $strtime = strtok( $ts, ';' );
2242         } 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 ) ) {
2243                 # TS_RFC850
2244                 $strtime = $ts;
2245         } 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 ) ) {
2246                 # asctime
2247                 $strtime = $ts;
2248         } else {
2249                 # Bogus value...
2250                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2251
2252                 return false;
2253         }
2254
2255         static $formats = array(
2256                 TS_UNIX => 'U',
2257                 TS_MW => 'YmdHis',
2258                 TS_DB => 'Y-m-d H:i:s',
2259                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2260                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2261                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2262                 TS_RFC2822 => 'D, d M Y H:i:s',
2263                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2264                 TS_POSTGRES => 'Y-m-d H:i:s',
2265                 TS_DB2 => 'Y-m-d H:i:s',
2266         );
2267
2268         if ( !isset( $formats[$outputtype] ) ) {
2269                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2270         }
2271
2272         if ( function_exists( "date_create" ) ) {
2273                 if ( count( $da ) ) {
2274                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2275                                 (int)$da[1], (int)$da[2], (int)$da[3],
2276                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2277
2278                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2279                 } elseif ( $strtime ) {
2280                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2281                 } else {
2282                         return false;
2283                 }
2284
2285                 if ( !$d ) {
2286                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2287                         return false;
2288                 }
2289
2290                 $output = $d->format( $formats[$outputtype] );
2291         } else {
2292                 if ( count( $da ) ) {
2293                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2294                         // We may want to handle that explicitly at some point
2295                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2296                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2297                 } elseif ( $strtime ) {
2298                         $uts = strtotime( $strtime );
2299                 }
2300
2301                 if ( $uts === false ) {
2302                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2303                         return false;
2304                 }
2305
2306                 if ( TS_UNIX == $outputtype ) {
2307                         return $uts;
2308                 }
2309                 $output = gmdate( $formats[$outputtype], $uts );
2310         }
2311
2312         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2313                 $output .= ' GMT';
2314         }
2315
2316         return $output;
2317 }
2318
2319 /**
2320  * Return a formatted timestamp, or null if input is null.
2321  * For dealing with nullable timestamp columns in the database.
2322  *
2323  * @param $outputtype Integer
2324  * @param $ts String
2325  * @return String
2326  */
2327 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2328         if( is_null( $ts ) ) {
2329                 return null;
2330         } else {
2331                 return wfTimestamp( $outputtype, $ts );
2332         }
2333 }
2334
2335 /**
2336  * Convenience function; returns MediaWiki timestamp for the present time.
2337  *
2338  * @return string
2339  */
2340 function wfTimestampNow() {
2341         # return NOW
2342         return wfTimestamp( TS_MW, time() );
2343 }
2344
2345 /**
2346  * Check if the operating system is Windows
2347  *
2348  * @return Bool: true if it's Windows, False otherwise.
2349  */
2350 function wfIsWindows() {
2351         static $isWindows = null;
2352         if ( $isWindows === null ) {
2353                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2354         }
2355         return $isWindows;
2356 }
2357
2358 /**
2359  * Check if we are running under HipHop
2360  *
2361  * @return Bool
2362  */
2363 function wfIsHipHop() {
2364         return function_exists( 'hphp_thread_set_warmup_enabled' );
2365 }
2366
2367 /**
2368  * Swap two variables
2369  *
2370  * @param $x Mixed
2371  * @param $y Mixed
2372  */
2373 function swap( &$x, &$y ) {
2374         $z = $x;
2375         $x = $y;
2376         $y = $z;
2377 }
2378
2379 /**
2380  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2381  * TEMP environment variables are then checked in sequence, and if none are set
2382  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2383  * or C:\Windows\Temp for Windows and hope for the best.
2384  * It is common to call it with tempnam().
2385  *
2386  * NOTE: When possible, use instead the tmpfile() function to create
2387  * temporary files to avoid race conditions on file creation, etc.
2388  *
2389  * @return String
2390  */
2391 function wfTempDir() {
2392         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2393                 $tmp = getenv( $var );
2394                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2395                         return $tmp;
2396                 }
2397         }
2398         if( function_exists( 'sys_get_temp_dir' ) ) {
2399                 return sys_get_temp_dir();
2400         }
2401         # Usual defaults
2402         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2403 }
2404
2405 /**
2406  * Make directory, and make all parent directories if they don't exist
2407  *
2408  * @param $dir String: full path to directory to create
2409  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2410  * @param $caller String: optional caller param for debugging.
2411  * @return bool
2412  */
2413 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2414         global $wgDirectoryMode;
2415
2416         if ( !is_null( $caller ) ) {
2417                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2418         }
2419
2420         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2421                 return true;
2422         }
2423
2424         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2425
2426         if ( is_null( $mode ) ) {
2427                 $mode = $wgDirectoryMode;
2428         }
2429
2430         // Turn off the normal warning, we're doing our own below
2431         wfSuppressWarnings();
2432         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2433         wfRestoreWarnings();
2434
2435         if( !$ok ) {
2436                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2437                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2438         }
2439         return $ok;
2440 }
2441
2442 /**
2443  * Increment a statistics counter
2444  *
2445  * @param $key String
2446  * @param $count Int
2447  */
2448 function wfIncrStats( $key, $count = 1 ) {
2449         global $wgStatsMethod;
2450
2451         $count = intval( $count );
2452
2453         if( $wgStatsMethod == 'udp' ) {
2454                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2455                 static $socket;
2456
2457                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2458
2459                 if ( !$socket ) {
2460                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2461                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2462                         socket_sendto(
2463                                 $socket,
2464                                 $statline,
2465                                 strlen( $statline ),
2466                                 0,
2467                                 $wgUDPProfilerHost,
2468                                 $wgUDPProfilerPort
2469                         );
2470                 }
2471                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2472                 wfSuppressWarnings();
2473                 socket_sendto(
2474                         $socket,
2475                         $statline,
2476                         strlen( $statline ),
2477                         0,
2478                         $wgUDPProfilerHost,
2479                         $wgUDPProfilerPort
2480                 );
2481                 wfRestoreWarnings();
2482         } elseif( $wgStatsMethod == 'cache' ) {
2483                 global $wgMemc;
2484                 $key = wfMemcKey( 'stats', $key );
2485                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2486                         $wgMemc->add( $key, $count );
2487                 }
2488         } else {
2489                 // Disabled
2490         }
2491 }
2492
2493 /**
2494  * @param $nr Mixed: the number to format
2495  * @param $acc Integer: the number of digits after the decimal point, default 2
2496  * @param $round Boolean: whether or not to round the value, default true
2497  * @return float
2498  */
2499 function wfPercent( $nr, $acc = 2, $round = true ) {
2500         $ret = sprintf( "%.${acc}f", $nr );
2501         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2502 }
2503
2504 /**
2505  * Find out whether or not a mixed variable exists in a string
2506  *
2507  * @param $needle String
2508  * @param $str String
2509  * @param $insensitive Boolean
2510  * @return Boolean
2511  */
2512 function in_string( $needle, $str, $insensitive = false ) {
2513         $func = 'strpos';
2514         if( $insensitive ) $func = 'stripos';
2515
2516         return $func( $str, $needle ) !== false;
2517 }
2518
2519 /**
2520  * Make a list item, used by various special pages
2521  *
2522  * @param $page String Page link
2523  * @param $details String Text between brackets
2524  * @param $oppositedm Boolean   Add the direction mark opposite to your
2525  *                                                              language, to display text properly
2526  * @return String
2527  */
2528 function wfSpecialList( $page, $details, $oppositedm = true ) {
2529         global $wgLang;
2530         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2531                 $wgLang->getDirMark();
2532         $details = $details ? $dirmark . " ($details)" : '';
2533         return $page . $details;
2534 }
2535
2536 /**
2537  * Safety wrapper around ini_get() for boolean settings.
2538  * The values returned from ini_get() are pre-normalized for settings
2539  * set via php.ini or php_flag/php_admin_flag... but *not*
2540  * for those set via php_value/php_admin_value.
2541  *
2542  * It's fairly common for people to use php_value instead of php_flag,
2543  * which can leave you with an 'off' setting giving a false positive
2544  * for code that just takes the ini_get() return value as a boolean.
2545  *
2546  * To make things extra interesting, setting via php_value accepts
2547  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2548  * Unrecognized values go false... again opposite PHP's own coercion
2549  * from string to bool.
2550  *
2551  * Luckily, 'properly' set settings will always come back as '0' or '1',
2552  * so we only have to worry about them and the 'improper' settings.
2553  *
2554  * I frickin' hate PHP... :P
2555  *
2556  * @param $setting String
2557  * @return Bool
2558  */
2559 function wfIniGetBool( $setting ) {
2560         $val = ini_get( $setting );
2561         // 'on' and 'true' can't have whitespace around them, but '1' can.
2562         return strtolower( $val ) == 'on'
2563                 || strtolower( $val ) == 'true'
2564                 || strtolower( $val ) == 'yes'
2565                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2566 }
2567
2568 /**
2569  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2570  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2571  *
2572  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2573  *                          should be omitted
2574  * @param $fileName String Name of the library, if not $extension.suffix
2575  * @return Bool - Whether or not the extension is loaded
2576  */
2577 function wfDl( $extension, $fileName = null ) {
2578         if( extension_loaded( $extension ) ) {
2579                 return true;
2580         }
2581
2582         $canDl = false;
2583         $sapi = php_sapi_name();
2584         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2585                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2586         {
2587                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2588                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2589         }
2590
2591         if( $canDl ) {
2592                 $fileName = $fileName ? $fileName : $extension;
2593                 if( wfIsWindows() ) {
2594                         $fileName = 'php_' . $fileName;
2595                 }
2596                 wfSuppressWarnings();
2597                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2598                 wfRestoreWarnings();
2599         }
2600         return extension_loaded( $extension );
2601 }
2602
2603 /**
2604  * Execute a shell command, with time and memory limits mirrored from the PHP
2605  * configuration if supported.
2606  * @param $cmd String Command line, properly escaped for shell.
2607  * @param &$retval optional, will receive the program's exit code.
2608  *                 (non-zero is usually failure)
2609  * @param $environ Array optional environment variables which should be
2610  *                 added to the executed command environment.
2611  * @return collected stdout as a string (trailing newlines stripped)
2612  */
2613 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2614         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2615
2616         static $disabled;
2617         if ( is_null( $disabled ) ) {
2618                 $disabled = false;
2619                 if( wfIniGetBool( 'safe_mode' ) ) {
2620                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2621                         $disabled = 'safemode';
2622                 } else {
2623                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2624                         $functions = array_map( 'trim', $functions );
2625                         $functions = array_map( 'strtolower', $functions );
2626                         if ( in_array( 'passthru', $functions ) ) {
2627                                 wfDebug( "passthru is in disabled_functions\n" );
2628                                 $disabled = 'passthru';
2629                         }
2630                 }
2631         }
2632         if ( $disabled ) {
2633                 $retval = 1;
2634                 return $disabled == 'safemode' ?
2635                         'Unable to run external programs in safe mode.' :
2636                         'Unable to run external programs, passthru() is disabled.';
2637         }
2638
2639         wfInitShellLocale();
2640
2641         $envcmd = '';
2642         foreach( $environ as $k => $v ) {
2643                 if ( wfIsWindows() ) {
2644                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2645                          * appear in the environment variable, so we must use carat escaping as documented in
2646                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2647                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2648                          * are listed there but doesn't appear to need it.
2649                          */
2650                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2651                 } else {
2652                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2653                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2654                          */
2655                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2656                 }
2657         }
2658         $cmd = $envcmd . $cmd;
2659
2660         if ( wfIsWindows() ) {
2661                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2662                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2663                 {
2664                         # Hack to work around PHP's flawed invocation of cmd.exe
2665                         # http://news.php.net/php.internals/21796
2666                         # Windows 9x doesn't accept any kind of quotes
2667                         $cmd = '"' . $cmd . '"';
2668                 }
2669         } elseif ( php_uname( 's' ) == 'Linux' ) {
2670                 $time = intval( $wgMaxShellTime );
2671                 $mem = intval( $wgMaxShellMemory );
2672                 $filesize = intval( $wgMaxShellFileSize );
2673
2674                 if ( $time > 0 && $mem > 0 ) {
2675                         $script = "$IP/bin/ulimit4.sh";
2676                         if ( is_executable( $script ) ) {
2677                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2678                         }
2679                 }
2680         }
2681         wfDebug( "wfShellExec: $cmd\n" );
2682
2683         $retval = 1; // error by default?
2684         ob_start();
2685         passthru( $cmd, $retval );
2686         $output = ob_get_contents();
2687         ob_end_clean();
2688
2689         if ( $retval == 127 ) {
2690                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2691         }
2692         return $output;
2693 }
2694
2695 /**
2696  * Workaround for http://bugs.php.net/bug.php?id=45132
2697  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2698  */
2699 function wfInitShellLocale() {
2700         static $done = false;
2701         if ( $done ) {
2702                 return;
2703         }
2704         $done = true;
2705         global $wgShellLocale;
2706         if ( !wfIniGetBool( 'safe_mode' ) ) {
2707                 putenv( "LC_CTYPE=$wgShellLocale" );
2708                 setlocale( LC_CTYPE, $wgShellLocale );
2709         }
2710 }
2711
2712 /**
2713  * This function works like "use VERSION" in Perl, the program will die with a
2714  * backtrace if the current version of PHP is less than the version provided
2715  *
2716  * This is useful for extensions which due to their nature are not kept in sync
2717  * with releases, and might depend on other versions of PHP than the main code
2718  *
2719  * Note: PHP might die due to parsing errors in some cases before it ever
2720  *       manages to call this function, such is life
2721  *
2722  * @see perldoc -f use
2723  *
2724  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2725  *                 a float
2726  */
2727 function wfUsePHP( $req_ver ) {
2728         $php_ver = PHP_VERSION;
2729
2730         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2731                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2732         }
2733 }
2734
2735 /**
2736  * This function works like "use VERSION" in Perl except it checks the version
2737  * of MediaWiki, the program will die with a backtrace if the current version
2738  * of MediaWiki is less than the version provided.
2739  *
2740  * This is useful for extensions which due to their nature are not kept in sync
2741  * with releases
2742  *
2743  * @see perldoc -f use
2744  *
2745  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2746  *                 a float
2747  */
2748 function wfUseMW( $req_ver ) {
2749         global $wgVersion;
2750
2751         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2752                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2753         }
2754 }
2755
2756 /**
2757  * Return the final portion of a pathname.
2758  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2759  * http://bugs.php.net/bug.php?id=33898
2760  *
2761  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2762  * We'll consider it so always, as we don't want \s in our Unix paths either.
2763  *
2764  * @param $path String
2765  * @param $suffix String: to remove if present
2766  * @return String
2767  */
2768 function wfBaseName( $path, $suffix = '' ) {
2769         $encSuffix = ( $suffix == '' )
2770                 ? ''
2771                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2772         $matches = array();
2773         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2774                 return $matches[1];
2775         } else {
2776                 return '';
2777         }
2778 }
2779
2780 /**
2781  * Generate a relative path name to the given file.
2782  * May explode on non-matching case-insensitive paths,
2783  * funky symlinks, etc.
2784  *
2785  * @param $path String: absolute destination path including target filename
2786  * @param $from String: Absolute source path, directory only
2787  * @return String
2788  */
2789 function wfRelativePath( $path, $from ) {
2790         // Normalize mixed input on Windows...
2791         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2792         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2793
2794         // Trim trailing slashes -- fix for drive root
2795         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2796         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2797
2798         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2799         $against = explode( DIRECTORY_SEPARATOR, $from );
2800
2801         if( $pieces[0] !== $against[0] ) {
2802                 // Non-matching Windows drive letters?
2803                 // Return a full path.
2804                 return $path;
2805         }
2806
2807         // Trim off common prefix
2808         while( count( $pieces ) && count( $against )
2809                 && $pieces[0] == $against[0] ) {
2810                 array_shift( $pieces );
2811                 array_shift( $against );
2812         }
2813
2814         // relative dots to bump us to the parent
2815         while( count( $against ) ) {
2816                 array_unshift( $pieces, '..' );
2817                 array_shift( $against );
2818         }
2819
2820         array_push( $pieces, wfBaseName( $path ) );
2821
2822         return implode( DIRECTORY_SEPARATOR, $pieces );
2823 }
2824
2825 /**
2826  * Do any deferred updates and clear the list
2827  *
2828  * @param $commit String: set to 'commit' to commit after every update to
2829  *                prevent lock contention
2830  */
2831 function wfDoUpdates( $commit = '' ) {
2832         global $wgDeferredUpdateList;
2833
2834         wfProfileIn( __METHOD__ );
2835
2836         // No need to get master connections in case of empty updates array
2837         if ( !count( $wgDeferredUpdateList ) ) {
2838                 wfProfileOut( __METHOD__ );
2839                 return;
2840         }
2841
2842         $doCommit = $commit == 'commit';
2843         if ( $doCommit ) {
2844                 $dbw = wfGetDB( DB_MASTER );
2845         }
2846
2847         foreach ( $wgDeferredUpdateList as $update ) {
2848                 $update->doUpdate();
2849
2850                 if ( $doCommit && $dbw->trxLevel() ) {
2851                         $dbw->commit();
2852                 }
2853         }
2854
2855         $wgDeferredUpdateList = array();
2856         wfProfileOut( __METHOD__ );
2857 }
2858
2859 /**
2860  * Convert an arbitrarily-long digit string from one numeric base
2861  * to another, optionally zero-padding to a minimum column width.
2862  *
2863  * Supports base 2 through 36; digit values 10-36 are represented
2864  * as lowercase letters a-z. Input is case-insensitive.
2865  *
2866  * @param $input String: of digits
2867  * @param $sourceBase Integer: 2-36
2868  * @param $destBase Integer: 2-36
2869  * @param $pad Integer: 1 or greater
2870  * @param $lowercase Boolean
2871  * @return String or false on invalid input
2872  */
2873 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2874         $input = strval( $input );
2875         if( $sourceBase < 2 ||
2876                 $sourceBase > 36 ||
2877                 $destBase < 2 ||
2878                 $destBase > 36 ||
2879                 $pad < 1 ||
2880                 $sourceBase != intval( $sourceBase ) ||
2881                 $destBase != intval( $destBase ) ||
2882                 $pad != intval( $pad ) ||
2883                 !is_string( $input ) ||
2884                 $input == '' ) {
2885                 return false;
2886         }
2887         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2888         $inDigits = array();
2889         $outChars = '';
2890
2891         // Decode and validate input string
2892         $input = strtolower( $input );
2893         for( $i = 0; $i < strlen( $input ); $i++ ) {
2894                 $n = strpos( $digitChars, $input[$i] );
2895                 if( $n === false || $n > $sourceBase ) {
2896                         return false;
2897                 }
2898                 $inDigits[] = $n;
2899         }
2900
2901         // Iterate over the input, modulo-ing out an output digit
2902         // at a time until input is gone.
2903         while( count( $inDigits ) ) {
2904                 $work = 0;
2905                 $workDigits = array();
2906
2907                 // Long division...
2908                 foreach( $inDigits as $digit ) {
2909                         $work *= $sourceBase;
2910                         $work += $digit;
2911
2912                         if( $work < $destBase ) {
2913                                 // Gonna need to pull another digit.
2914                                 if( count( $workDigits ) ) {
2915                                         // Avoid zero-padding; this lets us find
2916                                         // the end of the input very easily when
2917                                         // length drops to zero.
2918                                         $workDigits[] = 0;
2919                                 }
2920                         } else {
2921                                 // Finally! Actual division!
2922                                 $workDigits[] = intval( $work / $destBase );
2923
2924                                 // Isn't it annoying that most programming languages
2925                                 // don't have a single divide-and-remainder operator,
2926                                 // even though the CPU implements it that way?
2927                                 $work = $work % $destBase;
2928                         }
2929                 }
2930
2931                 // All that division leaves us with a remainder,
2932                 // which is conveniently our next output digit.
2933                 $outChars .= $digitChars[$work];
2934
2935                 // And we continue!
2936                 $inDigits = $workDigits;
2937         }
2938
2939         while( strlen( $outChars ) < $pad ) {
2940                 $outChars .= '0';
2941         }
2942
2943         return strrev( $outChars );
2944 }
2945
2946 /**
2947  * Create an object with a given name and an array of construct parameters
2948  *
2949  * @param $name String
2950  * @param $p Array: parameters
2951  * @deprecated since 1.18, warnings in 1.19, removal in 1.20
2952  */
2953 function wfCreateObject( $name, $p ) {
2954         wfDeprecated( __FUNCTION__ );
2955         return MWFunction::newObj( $name, $p );
2956 }
2957
2958 function wfHttpOnlySafe() {
2959         global $wgHttpOnlyBlacklist;
2960
2961         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2962                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2963                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2964                                 return false;
2965                         }
2966                 }
2967         }
2968
2969         return true;
2970 }
2971
2972 /**
2973  * Initialise php session
2974  *
2975  * @param $sessionId Bool
2976  */
2977 function wfSetupSession( $sessionId = false ) {
2978         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
2979                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
2980         if( $wgSessionsInMemcached ) {
2981                 if ( !defined( 'MW_COMPILED' ) ) {
2982                         global $IP;
2983                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
2984                 }
2985                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
2986                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
2987
2988                 // It's necessary to register a shutdown function to call session_write_close(),
2989                 // because by the time the request shutdown function for the session module is
2990                 // called, $wgMemc has already been destroyed. Shutdown functions registered
2991                 // this way are called before object destruction.
2992                 register_shutdown_function( 'memsess_write_close' );
2993         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
2994                 # Only set this if $wgSessionHandler isn't null and session.save_handler
2995                 # hasn't already been set to the desired value (that causes errors)
2996                 ini_set( 'session.save_handler', $wgSessionHandler );
2997         }
2998         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
2999         wfDebugLog( 'cookie',
3000                 'session_set_cookie_params: "' . implode( '", "',
3001                         array(
3002                                 0,
3003                                 $wgCookiePath,
3004                                 $wgCookieDomain,
3005                                 $wgCookieSecure,
3006                                 $httpOnlySafe ) ) . '"' );
3007         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3008         session_cache_limiter( 'private, must-revalidate' );
3009         if ( $sessionId ) {
3010                 session_id( $sessionId );
3011         }
3012         wfSuppressWarnings();
3013         session_start();
3014         wfRestoreWarnings();
3015 }
3016
3017 /**
3018  * Get an object from the precompiled serialized directory
3019  *
3020  * @param $name String
3021  * @return Mixed: the variable on success, false on failure
3022  */
3023 function wfGetPrecompiledData( $name ) {
3024         global $IP;
3025
3026         $file = "$IP/serialized/$name";
3027         if ( file_exists( $file ) ) {
3028                 $blob = file_get_contents( $file );
3029                 if ( $blob ) {
3030                         return unserialize( $blob );
3031                 }
3032         }
3033         return false;
3034 }
3035
3036 /**
3037  * Get a cache key
3038  *
3039  * @param varargs
3040  * @return String
3041  */
3042 function wfMemcKey( /*... */ ) {
3043         $args = func_get_args();
3044         $key = wfWikiID() . ':' . implode( ':', $args );
3045         $key = str_replace( ' ', '_', $key );
3046         return $key;
3047 }
3048
3049 /**
3050  * Get a cache key for a foreign DB
3051  *
3052  * @param $db String
3053  * @param $prefix String
3054  * @param varargs String
3055  * @return String
3056  */
3057 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3058         $args = array_slice( func_get_args(), 2 );
3059         if ( $prefix ) {
3060                 $key = "$db-$prefix:" . implode( ':', $args );
3061         } else {
3062                 $key = $db . ':' . implode( ':', $args );
3063         }
3064         return $key;
3065 }
3066
3067 /**
3068  * Get an ASCII string identifying this wiki
3069  * This is used as a prefix in memcached keys
3070  *
3071  * @return String
3072  */
3073 function wfWikiID() {
3074         global $wgDBprefix, $wgDBname;
3075         if ( $wgDBprefix ) {
3076                 return "$wgDBname-$wgDBprefix";
3077         } else {
3078                 return $wgDBname;
3079         }
3080 }
3081
3082 /**
3083  * Split a wiki ID into DB name and table prefix
3084  *
3085  * @param $wiki String
3086  * @param $bits String
3087  */
3088 function wfSplitWikiID( $wiki ) {
3089         $bits = explode( '-', $wiki, 2 );
3090         if ( count( $bits ) < 2 ) {
3091                 $bits[] = '';
3092         }
3093         return $bits;
3094 }
3095
3096 /**
3097  * Get a Database object.
3098  *
3099  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3100  *            master (for write queries), DB_SLAVE for potentially lagged read
3101  *            queries, or an integer >= 0 for a particular server.
3102  *
3103  * @param $groups Mixed: query groups. An array of group names that this query
3104  *                belongs to. May contain a single string if the query is only
3105  *                in one group.
3106  *
3107  * @param $wiki String: the wiki ID, or false for the current wiki
3108  *
3109  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3110  * will always return the same object, unless the underlying connection or load
3111  * balancer is manually destroyed.
3112  *
3113  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3114  * updater to ensure that a proper database is being updated.
3115  *
3116  * @return DatabaseBase
3117  */
3118 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3119         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3120 }
3121
3122 /**
3123  * Get a load balancer object.
3124  *
3125  * @param $wiki String: wiki ID, or false for the current wiki
3126  * @return LoadBalancer
3127  */
3128 function wfGetLB( $wiki = false ) {
3129         return wfGetLBFactory()->getMainLB( $wiki );
3130 }
3131
3132 /**
3133  * Get the load balancer factory object
3134  *
3135  * @return LBFactory
3136  */
3137 function &wfGetLBFactory() {
3138         return LBFactory::singleton();
3139 }
3140
3141 /**
3142  * Find a file.
3143  * Shortcut for RepoGroup::singleton()->findFile()
3144  *
3145  * @param $title String or Title object
3146  * @param $options Associative array of options:
3147  *     time:           requested time for an archived image, or false for the
3148  *                     current version. An image object will be returned which was
3149  *                     created at the specified time.
3150  *
3151  *     ignoreRedirect: If true, do not follow file redirects
3152  *
3153  *     private:        If true, return restricted (deleted) files if the current
3154  *                     user is allowed to view them. Otherwise, such files will not
3155  *                     be found.
3156  *
3157  *     bypassCache:    If true, do not use the process-local cache of File objects
3158  *
3159  * @return File, or false if the file does not exist
3160  */
3161 function wfFindFile( $title, $options = array() ) {
3162         return RepoGroup::singleton()->findFile( $title, $options );
3163 }
3164
3165 /**
3166  * Get an object referring to a locally registered file.
3167  * Returns a valid placeholder object if the file does not exist.
3168  *
3169  * @param $title Title or String
3170  * @return File, or null if passed an invalid Title
3171  */
3172 function wfLocalFile( $title ) {
3173         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3174 }
3175
3176 /**
3177  * Should low-performance queries be disabled?
3178  *
3179  * @return Boolean
3180  * @codeCoverageIgnore
3181  */
3182 function wfQueriesMustScale() {
3183         global $wgMiserMode;
3184         return $wgMiserMode
3185                 || ( SiteStats::pages() > 100000
3186                 && SiteStats::edits() > 1000000
3187                 && SiteStats::users() > 10000 );
3188 }
3189
3190 /**
3191  * Get the path to a specified script file, respecting file
3192  * extensions; this is a wrapper around $wgScriptExtension etc.
3193  *
3194  * @param $script String: script filename, sans extension
3195  * @return String
3196  */
3197 function wfScript( $script = 'index' ) {
3198         global $wgScriptPath, $wgScriptExtension;
3199         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3200 }
3201
3202 /**
3203  * Get the script URL.
3204  *
3205  * @return script URL
3206  */
3207 function wfGetScriptUrl() {
3208         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3209                 #
3210                 # as it was called, minus the query string.
3211                 #
3212                 # Some sites use Apache rewrite rules to handle subdomains,
3213                 # and have PHP set up in a weird way that causes PHP_SELF
3214                 # to contain the rewritten URL instead of the one that the
3215                 # outside world sees.
3216                 #
3217                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3218                 # provides containing the "before" URL.
3219                 return $_SERVER['SCRIPT_NAME'];
3220         } else {
3221                 return $_SERVER['URL'];
3222         }
3223 }
3224
3225 /**
3226  * Convenience function converts boolean values into "true"
3227  * or "false" (string) values
3228  *
3229  * @param $value Boolean
3230  * @return String
3231  */
3232 function wfBoolToStr( $value ) {
3233         return $value ? 'true' : 'false';
3234 }
3235
3236 /**
3237  * Load an extension messages file
3238  *
3239  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3240  * @codeCoverageIgnore
3241  */
3242 function wfLoadExtensionMessages() {
3243         wfDeprecated( __FUNCTION__ );
3244 }
3245
3246 /**
3247  * Get a platform-independent path to the null file, e.g. /dev/null
3248  *
3249  * @return string
3250  */
3251 function wfGetNull() {
3252         return wfIsWindows()
3253                 ? 'NUL'
3254                 : '/dev/null';
3255 }
3256
3257 /**
3258  * Throws a warning that $function is deprecated
3259  *
3260  * @param $function String
3261  * @return null
3262  */
3263 function wfDeprecated( $function ) {
3264         static $functionsWarned = array();
3265         if ( !isset( $functionsWarned[$function] ) ) {
3266                 $functionsWarned[$function] = true;
3267                 wfWarn( "Use of $function is deprecated.", 2 );
3268         }
3269 }
3270
3271 /**
3272  * Send a warning either to the debug log or in a PHP error depending on
3273  * $wgDevelopmentWarnings
3274  *
3275  * @param $msg String: message to send
3276  * @param $callerOffset Integer: number of items to go back in the backtrace to
3277  *        find the correct caller (1 = function calling wfWarn, ...)
3278  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3279  *        is true
3280  */
3281 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3282         global $wgDevelopmentWarnings;
3283
3284         $callers = wfDebugBacktrace();
3285         if ( isset( $callers[$callerOffset + 1] ) ) {
3286                 $callerfunc = $callers[$callerOffset + 1];
3287                 $callerfile = $callers[$callerOffset];
3288                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3289                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3290                 } else {
3291                         $file = '(internal function)';
3292                 }
3293                 $func = '';
3294                 if ( isset( $callerfunc['class'] ) ) {
3295                         $func .= $callerfunc['class'] . '::';
3296                 }
3297                 if ( isset( $callerfunc['function'] ) ) {
3298                         $func .= $callerfunc['function'];
3299                 }
3300                 $msg .= " [Called from $func in $file]";
3301         }
3302
3303         if ( $wgDevelopmentWarnings ) {
3304                 trigger_error( $msg, $level );
3305         } else {
3306                 wfDebug( "$msg\n" );
3307         }
3308 }
3309
3310 /**
3311  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3312  * and waiting for it to go down, this waits for the slaves to catch up to the
3313  * master position. Use this when updating very large numbers of rows, as
3314  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3315  * a no-op if there are no slaves.
3316  *
3317  * @param $maxLag Integer (deprecated)
3318  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3319  * @return null
3320  */
3321 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3322         $lb = wfGetLB( $wiki );
3323         // bug 27975 - Don't try to wait for slaves if there are none
3324         // Prevents permission error when getting master position
3325         if ( $lb->getServerCount() > 1 ) {
3326                 $dbw = $lb->getConnection( DB_MASTER );
3327                 $pos = $dbw->getMasterPos();
3328                 $lb->waitForAll( $pos );
3329         }
3330 }
3331
3332 /**
3333  * Used to be used for outputting text in the installer/updater
3334  * @deprecated since 1.18, warnings in 1.19, remove in 1.20
3335  */
3336 function wfOut( $s ) {
3337         wfDeprecated( __METHOD__ );
3338         global $wgCommandLineMode;
3339         if ( $wgCommandLineMode ) {
3340                 echo $s;
3341         } else {
3342                 echo htmlspecialchars( $s );
3343         }
3344         flush();
3345 }
3346
3347 /**
3348  * Count down from $n to zero on the terminal, with a one-second pause
3349  * between showing each number. For use in command-line scripts.
3350  * @codeCoverageIgnore
3351  */
3352 function wfCountDown( $n ) {
3353         for ( $i = $n; $i >= 0; $i-- ) {
3354                 if ( $i != $n ) {
3355                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3356                 }
3357                 echo $i;
3358                 flush();
3359                 if ( $i ) {
3360                         sleep( 1 );
3361                 }
3362         }
3363         echo "\n";
3364 }
3365
3366 /**
3367  * Generate a random 32-character hexadecimal token.
3368  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3369  *              characters before hashing.
3370  * @return string
3371  * @codeCoverageIgnore
3372  */
3373 function wfGenerateToken( $salt = '' ) {
3374         $salt = serialize( $salt );
3375         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3376 }
3377
3378 /**
3379  * Replace all invalid characters with -
3380  *
3381  * @param $name Mixed: filename to process
3382  * @return String
3383  */
3384 function wfStripIllegalFilenameChars( $name ) {
3385         global $wgIllegalFileChars;
3386         $name = wfBaseName( $name );
3387         $name = preg_replace(
3388                 "/[^" . Title::legalChars() . "]" .
3389                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3390                         "/",
3391                 '-',
3392                 $name
3393         );
3394         return $name;
3395 }
3396
3397 /**
3398  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3399  *
3400  * @return Integer value memory was set to.
3401  */
3402 function wfMemoryLimit() {
3403         global $wgMemoryLimit;
3404         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3405         if( $memlimit != -1 ) {
3406                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3407                 if( $conflimit == -1 ) {
3408                         wfDebug( "Removing PHP's memory limit\n" );
3409                         wfSuppressWarnings();
3410                         ini_set( 'memory_limit', $conflimit );
3411                         wfRestoreWarnings();
3412                         return $conflimit;
3413                 } elseif ( $conflimit > $memlimit ) {
3414                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3415                         wfSuppressWarnings();
3416                         ini_set( 'memory_limit', $conflimit );
3417                         wfRestoreWarnings();
3418                         return $conflimit;
3419                 }
3420         }
3421         return $memlimit;
3422 }
3423
3424 /**
3425  * Converts shorthand byte notation to integer form
3426  *
3427  * @param $string String
3428  * @return Integer
3429  */
3430 function wfShorthandToInteger( $string = '' ) {
3431         $string = trim( $string );
3432         if( $string === '' ) {
3433                 return -1;
3434         }
3435         $last = $string[strlen( $string ) - 1];
3436         $val = intval( $string );
3437         switch( $last ) {
3438                 case 'g':
3439                 case 'G':
3440                         $val *= 1024;
3441                         // break intentionally missing
3442                 case 'm':
3443                 case 'M':
3444                         $val *= 1024;
3445                         // break intentionally missing
3446                 case 'k':
3447                 case 'K':
3448                         $val *= 1024;
3449         }
3450
3451         return $val;
3452 }
3453
3454 /**
3455  * Get the normalised IETF language tag
3456  * See unit test for examples.
3457  *
3458  * @param $code String: The language code.
3459  * @return $langCode String: The language code which complying with BCP 47 standards.
3460  */
3461 function wfBCP47( $code ) {
3462         $codeSegment = explode( '-', $code );
3463         $codeBCP = array();
3464         foreach ( $codeSegment as $segNo => $seg ) {
3465                 if ( count( $codeSegment ) > 0 ) {
3466                         // when previous segment is x, it is a private segment and should be lc
3467                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3468                                 $codeBCP[$segNo] = strtolower( $seg );
3469                         // ISO 3166 country code
3470                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3471                                 $codeBCP[$segNo] = strtoupper( $seg );
3472                         // ISO 15924 script code
3473                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3474                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3475                         // Use lowercase for other cases
3476                         } else {
3477                                 $codeBCP[$segNo] = strtolower( $seg );
3478                         }
3479                 } else {
3480                 // Use lowercase for single segment
3481                         $codeBCP[$segNo] = strtolower( $seg );
3482                 }
3483         }
3484         $langCode = implode( '-', $codeBCP );
3485         return $langCode;
3486 }
3487
3488 /**
3489  * Get a cache object.
3490  *
3491  * @param $inputType integer Cache type, one the the CACHE_* constants.
3492  * @return BagOStuff
3493  */
3494 function wfGetCache( $inputType ) {
3495         return ObjectCache::getInstance( $inputType );
3496 }
3497
3498 /**
3499  * Get the main cache object
3500  *
3501  * @return BagOStuff
3502  */
3503 function wfGetMainCache() {
3504         global $wgMainCacheType;
3505         return ObjectCache::getInstance( $wgMainCacheType );
3506 }
3507
3508 /**
3509  * Get the cache object used by the message cache
3510  *
3511  * @return BagOStuff
3512  */
3513 function wfGetMessageCacheStorage() {
3514         global $wgMessageCacheType;
3515         return ObjectCache::getInstance( $wgMessageCacheType );
3516 }
3517
3518 /**
3519  * Get the cache object used by the parser cache
3520  *
3521  * @return BagOStuff
3522  */
3523 function wfGetParserCacheStorage() {
3524         global $wgParserCacheType;
3525         return ObjectCache::getInstance( $wgParserCacheType );
3526 }
3527
3528 /**
3529  * Call hook functions defined in $wgHooks
3530  *
3531  * @param $event String: event name
3532  * @param $args Array: parameters passed to hook functions
3533  * @return Boolean
3534  */
3535 function wfRunHooks( $event, $args = array() ) {
3536         return Hooks::run( $event, $args );
3537 }