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( $s ) ) {
 298                 $needle = null;
 299                 return;
 300         }
 301
 302         if ( is_null( $needle ) ) {
 303                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 304                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 305                         $needle[] = '%3A';
 306                 }
 307         }
 308
 309         $s = urlencode( $s );
 310         $s = str_ireplace(
 311                 $needle,
 312                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 313                 $s
 314         );
 315
 316         return $s;
 317 }
 318
 319 /**
 320  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 321  * "days=7&limit=100". Options in the first array override options in the second.
 322  * Options set to "" will not be output.
 323  *
 324  * @param $array1 Array ( String|Array )
 325  * @param $array2 Array ( String|Array )
 326  * @param $prefix String
 327  * @return String
 328  */
 329 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 330         if ( !is_null( $array2 ) ) {
 331                 $array1 = $array1 + $array2;
 332         }
 333
 334         $cgi = '';
 335         foreach ( $array1 as $key => $value ) {
 336                 if ( $value !== '' ) {
 337                         if ( $cgi != '' ) {
 338                                 $cgi .= '&';
 339                         }
 340                         if ( $prefix !== '' ) {
 341                                 $key = $prefix . "[$key]";
 342                         }
 343                         if ( is_array( $value ) ) {
 344                                 $firstTime = true;
 345                                 foreach ( $value as $k => $v ) {
 346                                         $cgi .= $firstTime ? '' : '&';
 347                                         if ( is_array( $v ) ) {
 348                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 349                                         } else {
 350                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 351                                         }
 352                                         $firstTime = false;
 353                                 }
 354                         } else {
 355                                 if ( is_object( $value ) ) {
 356                                         $value = $value->__toString();
 357                                 }
 358                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 359                         }
 360                 }
 361         }
 362         return $cgi;
 363 }
 364
 365 /**
 366  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 367  * its argument and returns the same string in array form.  This allows compa-
 368  * tibility with legacy functions that accept raw query strings instead of nice
 369  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 370  * valid query strings, or it will explode.
 371  *
 372  * @param $query String: query string
 373  * @return array Array version of input
 374  */
 375 function wfCgiToArray( $query ) {
 376         if ( isset( $query[0] ) && $query[0] == '?' ) {
 377                 $query = substr( $query, 1 );
 378         }
 379         $bits = explode( '&', $query );
 380         $ret = array();
 381         foreach ( $bits as $bit ) {
 382                 if ( $bit === '' ) {
 383                         continue;
 384                 }
 385                 list( $key, $value ) = explode( '=', $bit );
 386                 $key = urldecode( $key );
 387                 $value = urldecode( $value );
 388                 if ( strpos( $key, '[' ) !== false ) {
 389                         $keys = array_reverse( explode( '[', $key ) );
 390                         $key = array_pop( $keys );
 391                         $temp = $value;
 392                         foreach ( $keys as $k ) {
 393                                 $k = substr( $k, 0, -1 );
 394                                 $temp = array( $k => $temp );
 395                         }
 396                         if ( isset( $ret[$key] ) ) {
 397                                 $ret[$key] = array_merge( $ret[$key], $temp );
 398                         } else {
 399                                 $ret[$key] = $temp;
 400                         }
 401                 } else {
 402                         $ret[$key] = $value;
 403                 }
 404         }
 405         return $ret;
 406 }
 407
 408 /**
 409  * Append a query string to an existing URL, which may or may not already
 410  * have query string parameters already. If so, they will be combined.
 411  *
 412  * @param $url String
 413  * @param $query Mixed: string or associative array
 414  * @return string
 415  */
 416 function wfAppendQuery( $url, $query ) {
 417         if ( is_array( $query ) ) {
 418                 $query = wfArrayToCGI( $query );
 419         }
 420         if( $query != '' ) {
 421                 if( false === strpos( $url, '?' ) ) {
 422                         $url .= '?';
 423                 } else {
 424                         $url .= '&';
 425                 }
 426                 $url .= $query;
 427         }
 428         return $url;
 429 }
 430
 431 /**
 432  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 433  * is correct.
 434  *
 435  * The meaning of the PROTO_* constants is as follows:
 436  * PROTO_HTTP: Output a URL starting with http://
 437  * PROTO_HTTPS: Output a URL starting with https://
 438  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 439  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 440  *
 441  * @todo this won't work with current-path-relative URLs
 442  * like "subdir/foo.html", etc.
 443  *
 444  * @param $url String: either fully-qualified or a local path + query
 445  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the protocol to use if $url or $wgServer is protocol-relative
 446  * @return string Fully-qualified URL
 447  */
 448 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 449         global $wgServer;
 450         if ( $defaultProto === PROTO_CURRENT ) {
 451                 $defaultProto = WebRequest::detectProtocol() . '://';
 452         }
 453
 454         // Analyze $wgServer to obtain its protocol
 455         $bits = wfParseUrl( $wgServer );
 456         $serverHasProto = $bits && $bits['scheme'] != '';
 457         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 458
 459         if( substr( $url, 0, 2 ) == '//' ) {
 460                 return $defaultProtoWithoutSlashes . $url;
 461         } elseif( substr( $url, 0, 1 ) == '/' ) {
 462                 // If $wgServer is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 463                 return ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $wgServer . $url;
 464         } else {
 465                 return $url;
 466         }
 467 }
 468
 469 /**
 470  * Returns a regular expression of url protocols
 471  *
 472  * @return String
 473  */
 474 function wfUrlProtocols() {
 475         global $wgUrlProtocols;
 476
 477         static $retval = null;
 478         if ( !is_null( $retval ) ) {
 479                 return $retval;
 480         }
 481
 482         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 483         // with LocalSettings files from 1.5
 484         if ( is_array( $wgUrlProtocols ) ) {
 485                 $protocols = array();
 486                 foreach ( $wgUrlProtocols as $protocol ) {
 487                         $protocols[] = preg_quote( $protocol, '/' );
 488                 }
 489
 490                 $retval = implode( '|', $protocols );
 491         } else {
 492                 $retval = $wgUrlProtocols;
 493         }
 494         return $retval;
 495 }
 496
 497 /**
 498  * parse_url() work-alike, but non-broken.  Differences:
 499  *
 500  * 1) Does not raise warnings on bad URLs (just returns false)
 501  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 502  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 503  *
 504  * @param $url String: a URL to parse
 505  * @return Array: bits of the URL in an associative array, per PHP docs
 506  */
 507 function wfParseUrl( $url ) {
 508         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 509
 510         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 511         // way to handle them is to just prepend 'http:' and strip the protocol out later
 512         $wasRelative = substr( $url, 0, 2 ) == '//';
 513         if ( $wasRelative ) {
 514                 $url = "http:$url";
 515         }
 516         wfSuppressWarnings();
 517         $bits = parse_url( $url );
 518         wfRestoreWarnings();
 519         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 520         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 521         if ( !$bits || !isset( $bits['scheme'] ) ) {
 522                 return false;
 523         }
 524
 525         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 526         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 527                 $bits['delimiter'] = '://';
 528         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 529                 $bits['delimiter'] = ':';
 530                 // parse_url detects for news: and mailto: the host part of an url as path
 531                 // We have to correct this wrong detection
 532                 if ( isset( $bits['path'] ) ) {
 533                         $bits['host'] = $bits['path'];
 534                         $bits['path'] = '';
 535                 }
 536         } else {
 537                 return false;
 538         }
 539
 540         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 541         if ( !isset( $bits['host'] ) ) {
 542                 $bits['host'] = '';
 543
 544                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 545                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 546                         $bits['path'] = '/' . $bits['path'];
 547                 }
 548         }
 549
 550         // If the URL was protocol-relative, fix scheme and delimiter
 551         if ( $wasRelative ) {
 552                 $bits['scheme'] = '';
 553                 $bits['delimiter'] = '//';
 554         }
 555         return $bits;
 556 }
 557
 558 /**
 559  * Make a URL index, appropriate for the el_index field of externallinks.
 560  *
 561  * @param $url String
 562  * @return String
 563  */
 564 function wfMakeUrlIndex( $url ) {
 565         $bits = wfParseUrl( $url );
 566
 567         // Reverse the labels in the hostname, convert to lower case
 568         // For emails reverse domainpart only
 569         if ( $bits['scheme'] == 'mailto' ) {
 570                 $mailparts = explode( '@', $bits['host'], 2 );
 571                 if ( count( $mailparts ) === 2 ) {
 572                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 573                 } else {
 574                         // No domain specified, don't mangle it
 575                         $domainpart = '';
 576                 }
 577                 $reversedHost = $domainpart . '@' . $mailparts[0];
 578         } else {
 579                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 580         }
 581         // Add an extra dot to the end
 582         // Why? Is it in wrong place in mailto links?
 583         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 584                 $reversedHost .= '.';
 585         }
 586         // Reconstruct the pseudo-URL
 587         $prot = $bits['scheme'];
 588         $index = $prot . $bits['delimiter'] . $reversedHost;
 589         // Leave out user and password. Add the port, path, query and fragment
 590         if ( isset( $bits['port'] ) ) {
 591                 $index .= ':' . $bits['port'];
 592         }
 593         if ( isset( $bits['path'] ) ) {
 594                 $index .= $bits['path'];
 595         } else {
 596                 $index .= '/';
 597         }
 598         if ( isset( $bits['query'] ) ) {
 599                 $index .= '?' . $bits['query'];
 600         }
 601         if ( isset( $bits['fragment'] ) ) {
 602                 $index .= '#' . $bits['fragment'];
 603         }
 604         return $index;
 605 }
 606
 607 /**
 608  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 609  * In normal operation this is a NOP.
 610  *
 611  * Controlling globals:
 612  * $wgDebugLogFile - points to the log file
 613  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 614  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 615  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 616  *
 617  * @param $text String
 618  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 619  */
 620 function wfDebug( $text, $logonly = false ) {
 621         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 622         global $wgDebugLogPrefix, $wgShowDebug;
 623
 624         static $cache = array(); // Cache of unoutputted messages
 625         $text = wfDebugTimer() . $text;
 626
 627         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 628                 return;
 629         }
 630
 631         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 632                 $cache[] = $text;
 633
 634                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 635                         // add the message and any cached messages to the output
 636                         array_map( array( $wgOut, 'debug' ), $cache );
 637                         $cache = array();
 638                 }
 639         }
 640         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 641                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 642                         # Strip unprintables; they can switch terminal modes when binary data
 643                         # gets dumped, which is pretty annoying.
 644                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 645                         $text = $wgDebugLogPrefix . $text;
 646                         wfErrorLog( $text, $wgDebugLogFile );
 647                 }
 648         }
 649 }
 650
 651 /**
 652  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 653  */
 654 function wfIsDebugRawPage() {
 655         static $cache;
 656         if ( $cache !== null ) {
 657                 return $cache;
 658         }
 659         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 660         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 661                 || (
 662                         isset( $_SERVER['SCRIPT_NAME'] )
 663                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 664                 ) )
 665         {
 666                 $cache = true;
 667         } else {
 668                 $cache = false;
 669         }
 670         return $cache;
 671 }
 672
 673 /**
 674  * Get microsecond timestamps for debug logs
 675  *
 676  * @return string
 677  */
 678 function wfDebugTimer() {
 679         global $wgDebugTimestamps;
 680         if ( !$wgDebugTimestamps ) {
 681                 return '';
 682         }
 683         static $start = null;
 684
 685         if ( $start === null ) {
 686                 $start = microtime( true );
 687                 $prefix = "\n$start";
 688         } else {
 689                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 690         }
 691
 692         return $prefix . '  ';
 693 }
 694
 695 /**
 696  * Send a line giving PHP memory usage.
 697  *
 698  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 699  */
 700 function wfDebugMem( $exact = false ) {
 701         $mem = memory_get_usage();
 702         if( !$exact ) {
 703                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 704         } else {
 705                 $mem .= ' bytes';
 706         }
 707         wfDebug( "Memory usage: $mem\n" );
 708 }
 709
 710 /**
 711  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 712  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 713  *
 714  * @param $logGroup String
 715  * @param $text String
 716  * @param $public Bool: whether to log the event in the public log if no private
 717  *                     log file is specified, (default true)
 718  */
 719 function wfDebugLog( $logGroup, $text, $public = true ) {
 720         global $wgDebugLogGroups, $wgShowHostnames;
 721         $text = trim( $text ) . "\n";
 722         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 723                 $time = wfTimestamp( TS_DB );
 724                 $wiki = wfWikiID();
 725                 if ( $wgShowHostnames ) {
 726                         $host = wfHostname();
 727                 } else {
 728                         $host = '';
 729                 }
 730                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 731                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 732                 }
 733         } elseif ( $public === true ) {
 734                 wfDebug( $text, true );
 735         }
 736 }
 737
 738 /**
 739  * Log for database errors
 740  *
 741  * @param $text String: database error message.
 742  */
 743 function wfLogDBError( $text ) {
 744         global $wgDBerrorLog, $wgDBname;
 745         if ( $wgDBerrorLog ) {
 746                 $host = trim(`hostname`);
 747                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 748                 wfErrorLog( $text, $wgDBerrorLog );
 749         }
 750 }
 751
 752 /**
 753  * Log to a file without getting "file size exceeded" signals.
 754  *
 755  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 756  * send lines to the specified port, prefixed by the specified prefix and a space.
 757  *
 758  * @param $text String
 759  * @param $file String filename
 760  */
 761 function wfErrorLog( $text, $file ) {
 762         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 763                 # Needs the sockets extension
 764                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 765                         // IPv6 bracketed host
 766                         $host = $m[2];
 767                         $port = intval( $m[3] );
 768                         $prefix = isset( $m[4] ) ? $m[4] : false;
 769                         $domain = AF_INET6;
 770                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 771                         $host = $m[2];
 772                         if ( !IP::isIPv4( $host ) ) {
 773                                 $host = gethostbyname( $host );
 774                         }
 775                         $port = intval( $m[3] );
 776                         $prefix = isset( $m[4] ) ? $m[4] : false;
 777                         $domain = AF_INET;
 778                 } else {
 779                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 780                 }
 781
 782                 // Clean it up for the multiplexer
 783                 if ( strval( $prefix ) !== '' ) {
 784                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 785
 786                         // Limit to 64KB
 787                         if ( strlen( $text ) > 65534 ) {
 788                                 $text = substr( $text, 0, 65534 );
 789                         }
 790
 791                         if ( substr( $text, -1 ) != "\n" ) {
 792                                 $text .= "\n";
 793                         }
 794                 } elseif ( strlen( $text ) > 65535 ) {
 795                         $text = substr( $text, 0, 65535 );
 796                 }
 797
 798                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 799                 if ( !$sock ) {
 800                         return;
 801                 }
 802                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 803                 socket_close( $sock );
 804         } else {
 805                 wfSuppressWarnings();
 806                 $exists = file_exists( $file );
 807                 $size = $exists ? filesize( $file ) : false;
 808                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 809                         file_put_contents( $file, $text, FILE_APPEND );
 810                 }
 811                 wfRestoreWarnings();
 812         }
 813 }
 814
 815 /**
 816  * @todo document
 817  */
 818 function wfLogProfilingData() {
 819         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 820         global $wgProfileLimit, $wgUser;
 821
 822         $profiler = Profiler::instance();
 823
 824         # Profiling must actually be enabled...
 825         if ( $profiler->isStub() ) {
 826                 return;
 827         }
 828
 829         // Get total page request time and only show pages that longer than
 830         // $wgProfileLimit time (default is 0)
 831         $now = wfTime();
 832         $elapsed = $now - $wgRequestTime;
 833         if ( $elapsed <= $wgProfileLimit ) {
 834                 return;
 835         }
 836
 837         $profiler->logData();
 838
 839         // Check whether this should be logged in the debug file.
 840         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 841                 return;
 842         }
 843
 844         $forward = '';
 845         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 846                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 847         }
 848         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 849                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 850         }
 851         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 852                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 853         }
 854         if ( $forward ) {
 855                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 856         }
 857         // Don't load $wgUser at this late stage just for statistics purposes
 858         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 859         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 860                 $forward .= ' anon';
 861         }
 862         $log = sprintf( "%s\t%04.3f\t%s\n",
 863                 gmdate( 'YmdHis' ), $elapsed,
 864                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 865
 866         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 867 }
 868
 869 /**
 870  * Check if the wiki read-only lock file is present. This can be used to lock
 871  * off editing functions, but doesn't guarantee that the database will not be
 872  * modified.
 873  *
 874  * @return bool
 875  */
 876 function wfReadOnly() {
 877         global $wgReadOnlyFile, $wgReadOnly;
 878
 879         if ( !is_null( $wgReadOnly ) ) {
 880                 return (bool)$wgReadOnly;
 881         }
 882         if ( $wgReadOnlyFile == '' ) {
 883                 return false;
 884         }
 885         // Set $wgReadOnly for faster access next time
 886         if ( is_file( $wgReadOnlyFile ) ) {
 887                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 888         } else {
 889                 $wgReadOnly = false;
 890         }
 891         return (bool)$wgReadOnly;
 892 }
 893
 894 function wfReadOnlyReason() {
 895         global $wgReadOnly;
 896         wfReadOnly();
 897         return $wgReadOnly;
 898 }
 899
 900 /**
 901  * Return a Language object from $langcode
 902  *
 903  * @param $langcode Mixed: either:
 904  *                  - a Language object
 905  *                  - code of the language to get the message for, if it is
 906  *                    a valid code create a language for that language, if
 907  *                    it is a string but not a valid code then make a basic
 908  *                    language object
 909  *                  - a boolean: if it's false then use the current users
 910  *                    language (as a fallback for the old parameter
 911  *                    functionality), or if it is true then use the wikis
 912  * @return Language object
 913  */
 914 function wfGetLangObj( $langcode = false ) {
 915         # Identify which language to get or create a language object for.
 916         # Using is_object here due to Stub objects.
 917         if( is_object( $langcode ) ) {
 918                 # Great, we already have the object (hopefully)!
 919                 return $langcode;
 920         }
 921
 922         global $wgContLang, $wgLanguageCode;
 923         if( $langcode === true || $langcode === $wgLanguageCode ) {
 924                 # $langcode is the language code of the wikis content language object.
 925                 # or it is a boolean and value is true
 926                 return $wgContLang;
 927         }
 928
 929         global $wgLang;
 930         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 931                 # $langcode is the language code of user language object.
 932                 # or it was a boolean and value is false
 933                 return $wgLang;
 934         }
 935
 936         $validCodes = array_keys( Language::getLanguageNames() );
 937         if( in_array( $langcode, $validCodes ) ) {
 938                 # $langcode corresponds to a valid language.
 939                 return Language::factory( $langcode );
 940         }
 941
 942         # $langcode is a string, but not a valid language code; use content language.
 943         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 944         return $wgContLang;
 945 }
 946
 947 /**
 948  * Old function when $wgBetterDirectionality existed
 949  * Removed in core, kept in extensions for backwards compat.
 950  *
 951  * @deprecated since 1.18
 952  * @return Language
 953  */
 954 function wfUILang() {
 955         global $wgLang;
 956         return $wgLang;
 957 }
 958
 959 /**
 960  * This is the new function for getting translated interface messages.
 961  * See the Message class for documentation how to use them.
 962  * The intention is that this function replaces all old wfMsg* functions.
 963  * @param $key \string Message key.
 964  * Varargs: normal message parameters.
 965  * @return Message
 966  * @since 1.17
 967  */
 968 function wfMessage( $key /*...*/) {
 969         $params = func_get_args();
 970         array_shift( $params );
 971         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 972                 $params = $params[0];
 973         }
 974         return new Message( $key, $params );
 975 }
 976
 977 /**
 978  * This function accepts multiple message keys and returns a message instance
 979  * for the first message which is non-empty. If all messages are empty then an
 980  * instance of the first message key is returned.
 981  * @param varargs: message keys
 982  * @return Message
 983  * @since 1.18
 984  */
 985 function wfMessageFallback( /*...*/ ) {
 986         $args = func_get_args();
 987         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 988 }
 989
 990 /**
 991  * Get a message from anywhere, for the current user language.
 992  *
 993  * Use wfMsgForContent() instead if the message should NOT
 994  * change depending on the user preferences.
 995  *
 996  * @param $key String: lookup key for the message, usually
 997  *    defined in languages/Language.php
 998  *
 999  * Parameters to the message, which can be used to insert variable text into
1000  * it, can be passed to this function in the following formats:
1001  * - One per argument, starting at the second parameter
1002  * - As an array in the second parameter
1003  * These are not shown in the function definition.
1004  *
1005  * @return String
1006  */
1007 function wfMsg( $key ) {
1008         $args = func_get_args();
1009         array_shift( $args );
1010         return wfMsgReal( $key, $args );
1011 }
1012
1013 /**
1014  * Same as above except doesn't transform the message
1015  *
1016  * @param $key String
1017  * @return String
1018  */
1019 function wfMsgNoTrans( $key ) {
1020         $args = func_get_args();
1021         array_shift( $args );
1022         return wfMsgReal( $key, $args, true, false, false );
1023 }
1024
1025 /**
1026  * Get a message from anywhere, for the current global language
1027  * set with $wgLanguageCode.
1028  *
1029  * Use this if the message should NOT change dependent on the
1030  * language set in the user's preferences. This is the case for
1031  * most text written into logs, as well as link targets (such as
1032  * the name of the copyright policy page). Link titles, on the
1033  * other hand, should be shown in the UI language.
1034  *
1035  * Note that MediaWiki allows users to change the user interface
1036  * language in their preferences, but a single installation
1037  * typically only contains content in one language.
1038  *
1039  * Be wary of this distinction: If you use wfMsg() where you should
1040  * use wfMsgForContent(), a user of the software may have to
1041  * customize potentially hundreds of messages in
1042  * order to, e.g., fix a link in every possible language.
1043  *
1044  * @param $key String: lookup key for the message, usually
1045  *     defined in languages/Language.php
1046  * @return String
1047  */
1048 function wfMsgForContent( $key ) {
1049         global $wgForceUIMsgAsContentMsg;
1050         $args = func_get_args();
1051         array_shift( $args );
1052         $forcontent = true;
1053         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1054                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1055         {
1056                 $forcontent = false;
1057         }
1058         return wfMsgReal( $key, $args, true, $forcontent );
1059 }
1060
1061 /**
1062  * Same as above except doesn't transform the message
1063  *
1064  * @param $key String
1065  * @return String
1066  */
1067 function wfMsgForContentNoTrans( $key ) {
1068         global $wgForceUIMsgAsContentMsg;
1069         $args = func_get_args();
1070         array_shift( $args );
1071         $forcontent = true;
1072         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1073                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1074         {
1075                 $forcontent = false;
1076         }
1077         return wfMsgReal( $key, $args, true, $forcontent, false );
1078 }
1079
1080 /**
1081  * Really get a message
1082  *
1083  * @param $key String: key to get.
1084  * @param $args
1085  * @param $useDB Boolean
1086  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1087  * @param $transform Boolean: Whether or not to transform the message.
1088  * @return String: the requested message.
1089  */
1090 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1091         wfProfileIn( __METHOD__ );
1092         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1093         $message = wfMsgReplaceArgs( $message, $args );
1094         wfProfileOut( __METHOD__ );
1095         return $message;
1096 }
1097
1098 /**
1099  * Fetch a message string value, but don't replace any keys yet.
1100  *
1101  * @param $key String
1102  * @param $useDB Bool
1103  * @param $langCode String: Code of the language to get the message for, or
1104  *                  behaves as a content language switch if it is a boolean.
1105  * @param $transform Boolean: whether to parse magic words, etc.
1106  * @return string
1107  */
1108 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1109         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1110
1111         $cache = MessageCache::singleton();
1112         $message = $cache->get( $key, $useDB, $langCode );
1113         if( $message === false ) {
1114                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1115         } elseif ( $transform ) {
1116                 $message = $cache->transform( $message );
1117         }
1118         return $message;
1119 }
1120
1121 /**
1122  * Replace message parameter keys on the given formatted output.
1123  *
1124  * @param $message String
1125  * @param $args Array
1126  * @return string
1127  * @private
1128  */
1129 function wfMsgReplaceArgs( $message, $args ) {
1130         # Fix windows line-endings
1131         # Some messages are split with explode("\n", $msg)
1132         $message = str_replace( "\r", '', $message );
1133
1134         // Replace arguments
1135         if ( count( $args ) ) {
1136                 if ( is_array( $args[0] ) ) {
1137                         $args = array_values( $args[0] );
1138                 }
1139                 $replacementKeys = array();
1140                 foreach( $args as $n => $param ) {
1141                         $replacementKeys['$' . ( $n + 1 )] = $param;
1142                 }
1143                 $message = strtr( $message, $replacementKeys );
1144         }
1145
1146         return $message;
1147 }
1148
1149 /**
1150  * Return an HTML-escaped version of a message.
1151  * Parameter replacements, if any, are done *after* the HTML-escaping,
1152  * so parameters may contain HTML (eg links or form controls). Be sure
1153  * to pre-escape them if you really do want plaintext, or just wrap
1154  * the whole thing in htmlspecialchars().
1155  *
1156  * @param $key String
1157  * @param string ... parameters
1158  * @return string
1159  */
1160 function wfMsgHtml( $key ) {
1161         $args = func_get_args();
1162         array_shift( $args );
1163         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1164 }
1165
1166 /**
1167  * Return an HTML version of message
1168  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1169  * so parameters may contain HTML (eg links or form controls). Be sure
1170  * to pre-escape them if you really do want plaintext, or just wrap
1171  * the whole thing in htmlspecialchars().
1172  *
1173  * @param $key String
1174  * @param string ... parameters
1175  * @return string
1176  */
1177 function wfMsgWikiHtml( $key ) {
1178         $args = func_get_args();
1179         array_shift( $args );
1180         return wfMsgReplaceArgs(
1181                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1182                 /* can't be set to false */ true, /* interface */ true )->getText(),
1183                 $args );
1184 }
1185
1186 /**
1187  * Returns message in the requested format
1188  * @param $key String: key of the message
1189  * @param $options Array: processing rules. Can take the following options:
1190  *   <i>parse</i>: parses wikitext to HTML
1191  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1192  *       p's added by parser or tidy
1193  *   <i>escape</i>: filters message through htmlspecialchars
1194  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1195  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1196  *   <i>parsemag</i>: transform the message using magic phrases
1197  *   <i>content</i>: fetch message for content language instead of interface
1198  * Also can accept a single associative argument, of the form 'language' => 'xx':
1199  *   <i>language</i>: Language object or language code to fetch message for
1200  *       (overriden by <i>content</i>).
1201  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1202  *
1203  * @return String
1204  */
1205 function wfMsgExt( $key, $options ) {
1206         $args = func_get_args();
1207         array_shift( $args );
1208         array_shift( $args );
1209         $options = (array)$options;
1210
1211         foreach( $options as $arrayKey => $option ) {
1212                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1213                         # An unknown index, neither numeric nor "language"
1214                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1215                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1216                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1217                 'replaceafter', 'parsemag', 'content' ) ) ) {
1218                         # A numeric index with unknown value
1219                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1220                 }
1221         }
1222
1223         if( in_array( 'content', $options, true ) ) {
1224                 $forContent = true;
1225                 $langCode = true;
1226                 $langCodeObj = null;
1227         } elseif( array_key_exists( 'language', $options ) ) {
1228                 $forContent = false;
1229                 $langCode = wfGetLangObj( $options['language'] );
1230                 $langCodeObj = $langCode;
1231         } else {
1232                 $forContent = false;
1233                 $langCode = false;
1234                 $langCodeObj = null;
1235         }
1236
1237         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1238
1239         if( !in_array( 'replaceafter', $options, true ) ) {
1240                 $string = wfMsgReplaceArgs( $string, $args );
1241         }
1242
1243         $messageCache = MessageCache::singleton();
1244         if( in_array( 'parse', $options, true ) ) {
1245                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1246         } elseif ( in_array( 'parseinline', $options, true ) ) {
1247                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1248                 $m = array();
1249                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1250                         $string = $m[1];
1251                 }
1252         } elseif ( in_array( 'parsemag', $options, true ) ) {
1253                 $string = $messageCache->transform( $string,
1254                                 !$forContent, $langCodeObj );
1255         }
1256
1257         if ( in_array( 'escape', $options, true ) ) {
1258                 $string = htmlspecialchars ( $string );
1259         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1260                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1261         }
1262
1263         if( in_array( 'replaceafter', $options, true ) ) {
1264                 $string = wfMsgReplaceArgs( $string, $args );
1265         }
1266
1267         return $string;
1268 }
1269
1270 /**
1271  * Since wfMsg() and co suck, they don't return false if the message key they
1272  * looked up didn't exist but a XHTML string, this function checks for the
1273  * nonexistance of messages by checking the MessageCache::get() result directly.
1274  *
1275  * @param $key      String: the message key looked up
1276  * @return Boolean True if the message *doesn't* exist.
1277  */
1278 function wfEmptyMsg( $key ) {
1279         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1280 }
1281
1282 /**
1283  * Throw a debugging exception. This function previously once exited the process,
1284  * but now throws an exception instead, with similar results.
1285  *
1286  * @param $msg String: message shown when dieing.
1287  */
1288 function wfDebugDieBacktrace( $msg = '' ) {
1289         throw new MWException( $msg );
1290 }
1291
1292 /**
1293  * Fetch server name for use in error reporting etc.
1294  * Use real server name if available, so we know which machine
1295  * in a server farm generated the current page.
1296  *
1297  * @return string
1298  */
1299 function wfHostname() {
1300         static $host;
1301         if ( is_null( $host ) ) {
1302                 if ( function_exists( 'posix_uname' ) ) {
1303                         // This function not present on Windows
1304                         $uname = posix_uname();
1305                 } else {
1306                         $uname = false;
1307                 }
1308                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1309                         $host = $uname['nodename'];
1310                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1311                         # Windows computer name
1312                         $host = getenv( 'COMPUTERNAME' );
1313                 } else {
1314                         # This may be a virtual server.
1315                         $host = $_SERVER['SERVER_NAME'];
1316                 }
1317         }
1318         return $host;
1319 }
1320
1321 /**
1322  * Returns a HTML comment with the elapsed time since request.
1323  * This method has no side effects.
1324  *
1325  * @return string
1326  */
1327 function wfReportTime() {
1328         global $wgRequestTime, $wgShowHostnames;
1329
1330         $now = wfTime();
1331         $elapsed = $now - $wgRequestTime;
1332
1333         return $wgShowHostnames
1334                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1335                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1336 }
1337
1338 /**
1339  * Safety wrapper for debug_backtrace().
1340  *
1341  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1342  * murky circumstances, which may be triggered in part by stub objects
1343  * or other fancy talkin'.
1344  *
1345  * Will return an empty array if Zend Optimizer is detected or if
1346  * debug_backtrace is disabled, otherwise the output from
1347  * debug_backtrace() (trimmed).
1348  *
1349  * @return array of backtrace information
1350  */
1351 function wfDebugBacktrace( $limit = 0 ) {
1352         static $disabled = null;
1353
1354         if( extension_loaded( 'Zend Optimizer' ) ) {
1355                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1356                 return array();
1357         }
1358
1359         if ( is_null( $disabled ) ) {
1360                 $disabled = false;
1361                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1362                 $functions = array_map( 'trim', $functions );
1363                 $functions = array_map( 'strtolower', $functions );
1364                 if ( in_array( 'debug_backtrace', $functions ) ) {
1365                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1366                         $disabled = true;
1367                 }
1368         }
1369         if ( $disabled ) {
1370                 return array();
1371         }
1372
1373         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1374                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1375         } else {
1376                 return array_slice( debug_backtrace(), 1 );
1377         }
1378 }
1379
1380 /**
1381  * Get a debug backtrace as a string
1382  *
1383  * @return string
1384  */
1385 function wfBacktrace() {
1386         global $wgCommandLineMode;
1387
1388         if ( $wgCommandLineMode ) {
1389                 $msg = '';
1390         } else {
1391                 $msg = "<ul>\n";
1392         }
1393         $backtrace = wfDebugBacktrace();
1394         foreach( $backtrace as $call ) {
1395                 if( isset( $call['file'] ) ) {
1396                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1397                         $file = $f[count( $f ) - 1];
1398                 } else {
1399                         $file = '-';
1400                 }
1401                 if( isset( $call['line'] ) ) {
1402                         $line = $call['line'];
1403                 } else {
1404                         $line = '-';
1405                 }
1406                 if ( $wgCommandLineMode ) {
1407                         $msg .= "$file line $line calls ";
1408                 } else {
1409                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1410                 }
1411                 if( !empty( $call['class'] ) ) {
1412                         $msg .= $call['class'] . $call['type'];
1413                 }
1414                 $msg .= $call['function'] . '()';
1415
1416                 if ( $wgCommandLineMode ) {
1417                         $msg .= "\n";
1418                 } else {
1419                         $msg .= "</li>\n";
1420                 }
1421         }
1422         if ( $wgCommandLineMode ) {
1423                 $msg .= "\n";
1424         } else {
1425                 $msg .= "</ul>\n";
1426         }
1427
1428         return $msg;
1429 }
1430
1431 /**
1432  * Get the name of the function which called this function
1433  *
1434  * @param $level Int
1435  * @return Bool|string
1436  */
1437 function wfGetCaller( $level = 2 ) {
1438         $backtrace = wfDebugBacktrace( $level );
1439         if ( isset( $backtrace[$level] ) ) {
1440                 return wfFormatStackFrame( $backtrace[$level] );
1441         } else {
1442                 $caller = 'unknown';
1443         }
1444         return $caller;
1445 }
1446
1447 /**
1448  * Return a string consisting of callers in the stack. Useful sometimes
1449  * for profiling specific points.
1450  *
1451  * @param $limit The maximum depth of the stack frame to return, or false for
1452  *               the entire stack.
1453  * @return String
1454  */
1455 function wfGetAllCallers( $limit = 3 ) {
1456         $trace = array_reverse( wfDebugBacktrace() );
1457         if ( !$limit || $limit > count( $trace ) - 1 ) {
1458                 $limit = count( $trace ) - 1;
1459         }
1460         $trace = array_slice( $trace, -$limit - 1, $limit );
1461         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1462 }
1463
1464 /**
1465  * Return a string representation of frame
1466  *
1467  * @param $frame Array
1468  * @return Bool
1469  */
1470 function wfFormatStackFrame( $frame ) {
1471         return isset( $frame['class'] ) ?
1472                 $frame['class'] . '::' . $frame['function'] :
1473                 $frame['function'];
1474 }
1475
1476
1477 /* Some generic result counters, pulled out of SearchEngine */
1478
1479
1480 /**
1481  * @todo document
1482  *
1483  * @param $offset Int
1484  * @param $limit Int
1485  * @return String
1486  */
1487 function wfShowingResults( $offset, $limit ) {
1488         global $wgLang;
1489         return wfMsgExt(
1490                 'showingresults',
1491                 array( 'parseinline' ),
1492                 $wgLang->formatNum( $limit ),
1493                 $wgLang->formatNum( $offset + 1 )
1494         );
1495 }
1496
1497 /**
1498  * Generate (prev x| next x) (20|50|100...) type links for paging
1499  *
1500  * @param $offset String
1501  * @param $limit Integer
1502  * @param $link String
1503  * @param $query String: optional URL query parameter string
1504  * @param $atend Bool: optional param for specified if this is the last page
1505  * @return String
1506  */
1507 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1508         global $wgLang;
1509         $fmtLimit = $wgLang->formatNum( $limit );
1510         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1511         # Get prev/next link display text
1512         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1513         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1514         # Get prev/next link title text
1515         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1516         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1517         # Fetch the title object
1518         if( is_object( $link ) ) {
1519                 $title =& $link;
1520         } else {
1521                 $title = Title::newFromText( $link );
1522                 if( is_null( $title ) ) {
1523                         return false;
1524                 }
1525         }
1526         # Make 'previous' link
1527         if( 0 != $offset ) {
1528                 $po = $offset - $limit;
1529                 $po = max( $po, 0 );
1530                 $q = "limit={$limit}&offset={$po}";
1531                 if( $query != '' ) {
1532                         $q .= '&' . $query;
1533                 }
1534                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1535         } else {
1536                 $plink = $prev;
1537         }
1538         # Make 'next' link
1539         $no = $offset + $limit;
1540         $q = "limit={$limit}&offset={$no}";
1541         if( $query != '' ) {
1542                 $q .= '&' . $query;
1543         }
1544         if( $atend ) {
1545                 $nlink = $next;
1546         } else {
1547                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1548         }
1549         # Make links to set number of items per page
1550         $nums = $wgLang->pipeList( array(
1551                 wfNumLink( $offset, 20, $title, $query ),
1552                 wfNumLink( $offset, 50, $title, $query ),
1553                 wfNumLink( $offset, 100, $title, $query ),
1554                 wfNumLink( $offset, 250, $title, $query ),
1555                 wfNumLink( $offset, 500, $title, $query )
1556         ) );
1557         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1558 }
1559
1560 /**
1561  * Generate links for (20|50|100...) items-per-page links
1562  *
1563  * @param $offset String
1564  * @param $limit Integer
1565  * @param $title Title
1566  * @param $query String: optional URL query parameter string
1567  */
1568 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1569         global $wgLang;
1570         if( $query == '' ) {
1571                 $q = '';
1572         } else {
1573                 $q = $query.'&';
1574         }
1575         $q .= "limit={$limit}&offset={$offset}";
1576         $fmtLimit = $wgLang->formatNum( $limit );
1577         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1578         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1579         return $s;
1580 }
1581
1582 /**
1583  * @todo document
1584  * @todo FIXME: We may want to blacklist some broken browsers
1585  *
1586  * @param $force Bool
1587  * @return bool Whereas client accept gzip compression
1588  */
1589 function wfClientAcceptsGzip( $force = false ) {
1590         static $result = null;
1591         if ( $result === null || $force ) {
1592                 $result = false;
1593                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1594                         # @todo FIXME: We may want to blacklist some broken browsers
1595                         $m = array();
1596                         if( preg_match(
1597                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1598                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1599                                 $m )
1600                         )
1601                         {
1602                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1603                                         $result = false;
1604                                         return $result;
1605                                 }
1606                                 wfDebug( " accepts gzip\n" );
1607                                 $result = true;
1608                         }
1609                 }
1610         }
1611         return $result;
1612 }
1613
1614 /**
1615  * Obtain the offset and limit values from the request string;
1616  * used in special pages
1617  *
1618  * @param $deflimit Int default limit if none supplied
1619  * @param $optionname String Name of a user preference to check against
1620  * @return array
1621  *
1622  */
1623 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1624         global $wgRequest;
1625         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1626 }
1627
1628 /**
1629  * Escapes the given text so that it may be output using addWikiText()
1630  * without any linking, formatting, etc. making its way through. This
1631  * is achieved by substituting certain characters with HTML entities.
1632  * As required by the callers, <nowiki> is not used.
1633  *
1634  * @param $text String: text to be escaped
1635  * @return String
1636  */
1637 function wfEscapeWikiText( $text ) {
1638         $text = strtr( "\n$text", array(
1639                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1640                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1641                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1642                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1643                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1644                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1645         ) );
1646         return substr( $text, 1 );
1647 }
1648
1649 /**
1650  * Get the current unix timetstamp with microseconds.  Useful for profiling
1651  * @return Float
1652  */
1653 function wfTime() {
1654         return microtime( true );
1655 }
1656
1657 /**
1658  * Sets dest to source and returns the original value of dest
1659  * If source is NULL, it just returns the value, it doesn't set the variable
1660  * If force is true, it will set the value even if source is NULL
1661  *
1662  * @param $dest Mixed
1663  * @param $source Mixed
1664  * @param $force Bool
1665  * @return Mixed
1666  */
1667 function wfSetVar( &$dest, $source, $force = false ) {
1668         $temp = $dest;
1669         if ( !is_null( $source ) || $force ) {
1670                 $dest = $source;
1671         }
1672         return $temp;
1673 }
1674
1675 /**
1676  * As for wfSetVar except setting a bit
1677  *
1678  * @param $dest Int
1679  * @param $bit Int
1680  * @param $state Bool
1681  */
1682 function wfSetBit( &$dest, $bit, $state = true ) {
1683         $temp = (bool)( $dest & $bit );
1684         if ( !is_null( $state ) ) {
1685                 if ( $state ) {
1686                         $dest |= $bit;
1687                 } else {
1688                         $dest &= ~$bit;
1689                 }
1690         }
1691         return $temp;
1692 }
1693
1694 /**
1695  * Windows-compatible version of escapeshellarg()
1696  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1697  * function puts single quotes in regardless of OS.
1698  *
1699  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1700  * earlier distro releases of PHP)
1701  *
1702  * @param varargs
1703  * @return String
1704  */
1705 function wfEscapeShellArg( ) {
1706         wfInitShellLocale();
1707
1708         $args = func_get_args();
1709         $first = true;
1710         $retVal = '';
1711         foreach ( $args as $arg ) {
1712                 if ( !$first ) {
1713                         $retVal .= ' ';
1714                 } else {
1715                         $first = false;
1716                 }
1717
1718                 if ( wfIsWindows() ) {
1719                         // Escaping for an MSVC-style command line parser and CMD.EXE
1720                         // Refs:
1721                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1722                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1723                         //  * Bug #13518
1724                         //  * CR r63214
1725                         // Double the backslashes before any double quotes. Escape the double quotes.
1726                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1727                         $arg = '';
1728                         $iteration = 0;
1729                         foreach ( $tokens as $token ) {
1730                                 if ( $iteration % 2 == 1 ) {
1731                                         // Delimiter, a double quote preceded by zero or more slashes
1732                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1733                                 } elseif ( $iteration % 4 == 2 ) {
1734                                         // ^ in $token will be outside quotes, need to be escaped
1735                                         $arg .= str_replace( '^', '^^', $token );
1736                                 } else { // $iteration % 4 == 0
1737                                         // ^ in $token will appear inside double quotes, so leave as is
1738                                         $arg .= $token;
1739                                 }
1740                                 $iteration++;
1741                         }
1742                         // Double the backslashes before the end of the string, because
1743                         // we will soon add a quote
1744                         $m = array();
1745                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1746                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1747                         }
1748
1749                         // Add surrounding quotes
1750                         $retVal .= '"' . $arg . '"';
1751                 } else {
1752                         $retVal .= escapeshellarg( $arg );
1753                 }
1754         }
1755         return $retVal;
1756 }
1757
1758 /**
1759  * wfMerge attempts to merge differences between three texts.
1760  * Returns true for a clean merge and false for failure or a conflict.
1761  *
1762  * @param $old String
1763  * @param $mine String
1764  * @param $yours String
1765  * @param $result String
1766  * @return Bool
1767  */
1768 function wfMerge( $old, $mine, $yours, &$result ) {
1769         global $wgDiff3;
1770
1771         # This check may also protect against code injection in
1772         # case of broken installations.
1773         wfSuppressWarnings();
1774         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1775         wfRestoreWarnings();
1776
1777         if( !$haveDiff3 ) {
1778                 wfDebug( "diff3 not found\n" );
1779                 return false;
1780         }
1781
1782         # Make temporary files
1783         $td = wfTempDir();
1784         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1785         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1786         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1787
1788         fwrite( $oldtextFile, $old );
1789         fclose( $oldtextFile );
1790         fwrite( $mytextFile, $mine );
1791         fclose( $mytextFile );
1792         fwrite( $yourtextFile, $yours );
1793         fclose( $yourtextFile );
1794
1795         # Check for a conflict
1796         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1797                 wfEscapeShellArg( $mytextName ) . ' ' .
1798                 wfEscapeShellArg( $oldtextName ) . ' ' .
1799                 wfEscapeShellArg( $yourtextName );
1800         $handle = popen( $cmd, 'r' );
1801
1802         if( fgets( $handle, 1024 ) ) {
1803                 $conflict = true;
1804         } else {
1805                 $conflict = false;
1806         }
1807         pclose( $handle );
1808
1809         # Merge differences
1810         $cmd = $wgDiff3 . ' -a -e --merge ' .
1811                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1812         $handle = popen( $cmd, 'r' );
1813         $result = '';
1814         do {
1815                 $data = fread( $handle, 8192 );
1816                 if ( strlen( $data ) == 0 ) {
1817                         break;
1818                 }
1819                 $result .= $data;
1820         } while ( true );
1821         pclose( $handle );
1822         unlink( $mytextName );
1823         unlink( $oldtextName );
1824         unlink( $yourtextName );
1825
1826         if ( $result === '' && $old !== '' && !$conflict ) {
1827                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1828                 $conflict = true;
1829         }
1830         return !$conflict;
1831 }
1832
1833 /**
1834  * Returns unified plain-text diff of two texts.
1835  * Useful for machine processing of diffs.
1836  *
1837  * @param $before String: the text before the changes.
1838  * @param $after String: the text after the changes.
1839  * @param $params String: command-line options for the diff command.
1840  * @return String: unified diff of $before and $after
1841  */
1842 function wfDiff( $before, $after, $params = '-u' ) {
1843         if ( $before == $after ) {
1844                 return '';
1845         }
1846
1847         global $wgDiff;
1848         wfSuppressWarnings();
1849         $haveDiff = $wgDiff && file_exists( $wgDiff );
1850         wfRestoreWarnings();
1851
1852         # This check may also protect against code injection in
1853         # case of broken installations.
1854         if( !$haveDiff ) {
1855                 wfDebug( "diff executable not found\n" );
1856                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1857                 $format = new UnifiedDiffFormatter();
1858                 return $format->format( $diffs );
1859         }
1860
1861         # Make temporary files
1862         $td = wfTempDir();
1863         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1864         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1865
1866         fwrite( $oldtextFile, $before );
1867         fclose( $oldtextFile );
1868         fwrite( $newtextFile, $after );
1869         fclose( $newtextFile );
1870
1871         // Get the diff of the two files
1872         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1873
1874         $h = popen( $cmd, 'r' );
1875
1876         $diff = '';
1877
1878         do {
1879                 $data = fread( $h, 8192 );
1880                 if ( strlen( $data ) == 0 ) {
1881                         break;
1882                 }
1883                 $diff .= $data;
1884         } while ( true );
1885
1886         // Clean up
1887         pclose( $h );
1888         unlink( $oldtextName );
1889         unlink( $newtextName );
1890
1891         // Kill the --- and +++ lines. They're not useful.
1892         $diff_lines = explode( "\n", $diff );
1893         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1894                 unset( $diff_lines[0] );
1895         }
1896         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1897                 unset( $diff_lines[1] );
1898         }
1899
1900         $diff = implode( "\n", $diff_lines );
1901
1902         return $diff;
1903 }
1904
1905 /**
1906  * A wrapper around the PHP function var_export().
1907  * Either print it or add it to the regular output ($wgOut).
1908  *
1909  * @param $var A PHP variable to dump.
1910  */
1911 function wfVarDump( $var ) {
1912         global $wgOut;
1913         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1914         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1915                 print $s;
1916         } else {
1917                 $wgOut->addHTML( $s );
1918         }
1919 }
1920
1921 /**
1922  * Provide a simple HTTP error.
1923  *
1924  * @param $code Int|String
1925  * @param $label String
1926  * @param $desc String
1927  */
1928 function wfHttpError( $code, $label, $desc ) {
1929         global $wgOut;
1930         $wgOut->disable();
1931         header( "HTTP/1.0 $code $label" );
1932         header( "Status: $code $label" );
1933         $wgOut->sendCacheControl();
1934
1935         header( 'Content-type: text/html; charset=utf-8' );
1936         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1937                 '<html><head><title>' .
1938                 htmlspecialchars( $label ) .
1939                 '</title></head><body><h1>' .
1940                 htmlspecialchars( $label ) .
1941                 '</h1><p>' .
1942                 nl2br( htmlspecialchars( $desc ) ) .
1943                 "</p></body></html>\n";
1944 }
1945
1946 /**
1947  * Clear away any user-level output buffers, discarding contents.
1948  *
1949  * Suitable for 'starting afresh', for instance when streaming
1950  * relatively large amounts of data without buffering, or wanting to
1951  * output image files without ob_gzhandler's compression.
1952  *
1953  * The optional $resetGzipEncoding parameter controls suppression of
1954  * the Content-Encoding header sent by ob_gzhandler; by default it
1955  * is left. See comments for wfClearOutputBuffers() for why it would
1956  * be used.
1957  *
1958  * Note that some PHP configuration options may add output buffer
1959  * layers which cannot be removed; these are left in place.
1960  *
1961  * @param $resetGzipEncoding Bool
1962  */
1963 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1964         if( $resetGzipEncoding ) {
1965                 // Suppress Content-Encoding and Content-Length
1966                 // headers from 1.10+s wfOutputHandler
1967                 global $wgDisableOutputCompression;
1968                 $wgDisableOutputCompression = true;
1969         }
1970         while( $status = ob_get_status() ) {
1971                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1972                         // Probably from zlib.output_compression or other
1973                         // PHP-internal setting which can't be removed.
1974                         //
1975                         // Give up, and hope the result doesn't break
1976                         // output behavior.
1977                         break;
1978                 }
1979                 if( !ob_end_clean() ) {
1980                         // Could not remove output buffer handler; abort now
1981                         // to avoid getting in some kind of infinite loop.
1982                         break;
1983                 }
1984                 if( $resetGzipEncoding ) {
1985                         if( $status['name'] == 'ob_gzhandler' ) {
1986                                 // Reset the 'Content-Encoding' field set by this handler
1987                                 // so we can start fresh.
1988                                 if ( function_exists( 'header_remove' ) ) {
1989                                         // Available since PHP 5.3.0
1990                                         header_remove( 'Content-Encoding' );
1991                                 } else {
1992                                         // We need to provide a valid content-coding. See bug 28069
1993                                         header( 'Content-Encoding: identity' );
1994                                 }
1995                                 break;
1996                         }
1997                 }
1998         }
1999 }
2000
2001 /**
2002  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2003  *
2004  * Clear away output buffers, but keep the Content-Encoding header
2005  * produced by ob_gzhandler, if any.
2006  *
2007  * This should be used for HTTP 304 responses, where you need to
2008  * preserve the Content-Encoding header of the real result, but
2009  * also need to suppress the output of ob_gzhandler to keep to spec
2010  * and avoid breaking Firefox in rare cases where the headers and
2011  * body are broken over two packets.
2012  */
2013 function wfClearOutputBuffers() {
2014         wfResetOutputBuffers( false );
2015 }
2016
2017 /**
2018  * Converts an Accept-* header into an array mapping string values to quality
2019  * factors
2020  *
2021  * @param $accept String
2022  * @param $def String default
2023  * @return Array
2024  */
2025 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2026         # No arg means accept anything (per HTTP spec)
2027         if( !$accept ) {
2028                 return array( $def => 1.0 );
2029         }
2030
2031         $prefs = array();
2032
2033         $parts = explode( ',', $accept );
2034
2035         foreach( $parts as $part ) {
2036                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2037                 $values = explode( ';', trim( $part ) );
2038                 $match = array();
2039                 if ( count( $values ) == 1 ) {
2040                         $prefs[$values[0]] = 1.0;
2041                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2042                         $prefs[$values[0]] = floatval( $match[1] );
2043                 }
2044         }
2045
2046         return $prefs;
2047 }
2048
2049 /**
2050  * Checks if a given MIME type matches any of the keys in the given
2051  * array. Basic wildcards are accepted in the array keys.
2052  *
2053  * Returns the matching MIME type (or wildcard) if a match, otherwise
2054  * NULL if no match.
2055  *
2056  * @param $type String
2057  * @param $avail Array
2058  * @return string
2059  * @private
2060  */
2061 function mimeTypeMatch( $type, $avail ) {
2062         if( array_key_exists( $type, $avail ) ) {
2063                 return $type;
2064         } else {
2065                 $parts = explode( '/', $type );
2066                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2067                         return $parts[0] . '/*';
2068                 } elseif( array_key_exists( '*/*', $avail ) ) {
2069                         return '*/*';
2070                 } else {
2071                         return null;
2072                 }
2073         }
2074 }
2075
2076 /**
2077  * Returns the 'best' match between a client's requested internet media types
2078  * and the server's list of available types. Each list should be an associative
2079  * array of type to preference (preference is a float between 0.0 and 1.0).
2080  * Wildcards in the types are acceptable.
2081  *
2082  * @param $cprefs Array: client's acceptable type list
2083  * @param $sprefs Array: server's offered types
2084  * @return string
2085  *
2086  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2087  * XXX: generalize to negotiate other stuff
2088  */
2089 function wfNegotiateType( $cprefs, $sprefs ) {
2090         $combine = array();
2091
2092         foreach( array_keys($sprefs) as $type ) {
2093                 $parts = explode( '/', $type );
2094                 if( $parts[1] != '*' ) {
2095                         $ckey = mimeTypeMatch( $type, $cprefs );
2096                         if( $ckey ) {
2097                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2098                         }
2099                 }
2100         }
2101
2102         foreach( array_keys( $cprefs ) as $type ) {
2103                 $parts = explode( '/', $type );
2104                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2105                         $skey = mimeTypeMatch( $type, $sprefs );
2106                         if( $skey ) {
2107                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2108                         }
2109                 }
2110         }
2111
2112         $bestq = 0;
2113         $besttype = null;
2114
2115         foreach( array_keys( $combine ) as $type ) {
2116                 if( $combine[$type] > $bestq ) {
2117                         $besttype = $type;
2118                         $bestq = $combine[$type];
2119                 }
2120         }
2121
2122         return $besttype;
2123 }
2124
2125 /**
2126  * Reference-counted warning suppression
2127  *
2128  * @param $end Bool
2129  */
2130 function wfSuppressWarnings( $end = false ) {
2131         static $suppressCount = 0;
2132         static $originalLevel = false;
2133
2134         if ( $end ) {
2135                 if ( $suppressCount ) {
2136                         --$suppressCount;
2137                         if ( !$suppressCount ) {
2138                                 error_reporting( $originalLevel );
2139                         }
2140                 }
2141         } else {
2142                 if ( !$suppressCount ) {
2143                         // E_DEPRECATED is undefined in PHP 5.2
2144                         if( !defined( 'E_DEPRECATED' ) ){
2145                                 define( 'E_DEPRECATED', 8192 );
2146                         }
2147                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2148                 }
2149                 ++$suppressCount;
2150         }
2151 }
2152
2153 /**
2154  * Restore error level to previous value
2155  */
2156 function wfRestoreWarnings() {
2157         wfSuppressWarnings( true );
2158 }
2159
2160 # Autodetect, convert and provide timestamps of various types
2161
2162 /**
2163  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2164  */
2165 define( 'TS_UNIX', 0 );
2166
2167 /**
2168  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2169  */
2170 define( 'TS_MW', 1 );
2171
2172 /**
2173  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2174  */
2175 define( 'TS_DB', 2 );
2176
2177 /**
2178  * RFC 2822 format, for E-mail and HTTP headers
2179  */
2180 define( 'TS_RFC2822', 3 );
2181
2182 /**
2183  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2184  *
2185  * This is used by Special:Export
2186  */
2187 define( 'TS_ISO_8601', 4 );
2188
2189 /**
2190  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2191  *
2192  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2193  *       DateTime tag and page 36 for the DateTimeOriginal and
2194  *       DateTimeDigitized tags.
2195  */
2196 define( 'TS_EXIF', 5 );
2197
2198 /**
2199  * Oracle format time.
2200  */
2201 define( 'TS_ORACLE', 6 );
2202
2203 /**
2204  * Postgres format time.
2205  */
2206 define( 'TS_POSTGRES', 7 );
2207
2208 /**
2209  * DB2 format time
2210  */
2211 define( 'TS_DB2', 8 );
2212
2213 /**
2214  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2215  */
2216 define( 'TS_ISO_8601_BASIC', 9 );
2217
2218 /**
2219  * Get a timestamp string in one of various formats
2220  *
2221  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2222  *                    function will autodetect which format is supplied and act
2223  *                    accordingly.
2224  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2225  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2226  */
2227 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2228         $uts = 0;
2229         $da = array();
2230         $strtime = '';
2231
2232         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2233                 $uts = time();
2234                 $strtime = "@$uts";
2235         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2236                 # TS_DB
2237         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2238                 # TS_EXIF
2239         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2240                 # TS_MW
2241         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2242                 # TS_UNIX
2243                 $uts = $ts;
2244                 $strtime = "@$ts"; // Undocumented?
2245         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2246                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2247                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2248                                 str_replace( '+00:00', 'UTC', $ts ) );
2249         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2250                 # TS_ISO_8601
2251         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2252                 #TS_ISO_8601_BASIC
2253         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2254                 # TS_POSTGRES
2255         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2256                 # TS_POSTGRES
2257         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2258                 # TS_DB2
2259         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2260                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2261                                                         '[ \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
2262                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2263                 # The regex is a superset of rfc2822 for readability
2264                 $strtime = strtok( $ts, ';' );
2265         } 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 ) ) {
2266                 # TS_RFC850
2267                 $strtime = $ts;
2268         } 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 ) ) {
2269                 # asctime
2270                 $strtime = $ts;
2271         } else {
2272                 # Bogus value...
2273                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2274
2275                 return false;
2276         }
2277
2278         static $formats = array(
2279                 TS_UNIX => 'U',
2280                 TS_MW => 'YmdHis',
2281                 TS_DB => 'Y-m-d H:i:s',
2282                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2283                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2284                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2285                 TS_RFC2822 => 'D, d M Y H:i:s',
2286                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2287                 TS_POSTGRES => 'Y-m-d H:i:s',
2288                 TS_DB2 => 'Y-m-d H:i:s',
2289         );
2290
2291         if ( !isset( $formats[$outputtype] ) ) {
2292                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2293         }
2294
2295         if ( function_exists( "date_create" ) ) {
2296                 if ( count( $da ) ) {
2297                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2298                                 (int)$da[1], (int)$da[2], (int)$da[3],
2299                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2300
2301                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2302                 } elseif ( $strtime ) {
2303                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2304                 } else {
2305                         return false;
2306                 }
2307
2308                 if ( !$d ) {
2309                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2310                         return false;
2311                 }
2312
2313                 $output = $d->format( $formats[$outputtype] );
2314         } else {
2315                 if ( count( $da ) ) {
2316                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2317                         // We may want to handle that explicitly at some point
2318                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2319                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2320                 } elseif ( $strtime ) {
2321                         $uts = strtotime( $strtime );
2322                 }
2323
2324                 if ( $uts === false ) {
2325                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2326                         return false;
2327                 }
2328
2329                 if ( TS_UNIX == $outputtype ) {
2330                         return $uts;
2331                 }
2332                 $output = gmdate( $formats[$outputtype], $uts );
2333         }
2334
2335         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2336                 $output .= ' GMT';
2337         }
2338
2339         return $output;
2340 }
2341
2342 /**
2343  * Return a formatted timestamp, or null if input is null.
2344  * For dealing with nullable timestamp columns in the database.
2345  *
2346  * @param $outputtype Integer
2347  * @param $ts String
2348  * @return String
2349  */
2350 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2351         if( is_null( $ts ) ) {
2352                 return null;
2353         } else {
2354                 return wfTimestamp( $outputtype, $ts );
2355         }
2356 }
2357
2358 /**
2359  * Convenience function; returns MediaWiki timestamp for the present time.
2360  *
2361  * @return string
2362  */
2363 function wfTimestampNow() {
2364         # return NOW
2365         return wfTimestamp( TS_MW, time() );
2366 }
2367
2368 /**
2369  * Check if the operating system is Windows
2370  *
2371  * @return Bool: true if it's Windows, False otherwise.
2372  */
2373 function wfIsWindows() {
2374         static $isWindows = null;
2375         if ( $isWindows === null ) {
2376                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2377         }
2378         return $isWindows;
2379 }
2380
2381 /**
2382  * Check if we are running under HipHop
2383  *
2384  * @return Bool
2385  */
2386 function wfIsHipHop() {
2387         return function_exists( 'hphp_thread_set_warmup_enabled' );
2388 }
2389
2390 /**
2391  * Swap two variables
2392  *
2393  * @param $x Mixed
2394  * @param $y Mixed
2395  */
2396 function swap( &$x, &$y ) {
2397         $z = $x;
2398         $x = $y;
2399         $y = $z;
2400 }
2401
2402 /**
2403  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2404  * TEMP environment variables are then checked in sequence, and if none are set
2405  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2406  * or C:\Windows\Temp for Windows and hope for the best.
2407  * It is common to call it with tempnam().
2408  *
2409  * NOTE: When possible, use instead the tmpfile() function to create
2410  * temporary files to avoid race conditions on file creation, etc.
2411  *
2412  * @return String
2413  */
2414 function wfTempDir() {
2415         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2416                 $tmp = getenv( $var );
2417                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2418                         return $tmp;
2419                 }
2420         }
2421         if( function_exists( 'sys_get_temp_dir' ) ) {
2422                 return sys_get_temp_dir();
2423         }
2424         # Usual defaults
2425         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2426 }
2427
2428 /**
2429  * Make directory, and make all parent directories if they don't exist
2430  *
2431  * @param $dir String: full path to directory to create
2432  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2433  * @param $caller String: optional caller param for debugging.
2434  * @return bool
2435  */
2436 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2437         global $wgDirectoryMode;
2438
2439         if ( !is_null( $caller ) ) {
2440                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2441         }
2442
2443         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2444                 return true;
2445         }
2446
2447         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2448
2449         if ( is_null( $mode ) ) {
2450                 $mode = $wgDirectoryMode;
2451         }
2452
2453         // Turn off the normal warning, we're doing our own below
2454         wfSuppressWarnings();
2455         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2456         wfRestoreWarnings();
2457
2458         if( !$ok ) {
2459                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2460                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2461         }
2462         return $ok;
2463 }
2464
2465 /**
2466  * Increment a statistics counter
2467  *
2468  * @param $key String
2469  * @param $count Int
2470  */
2471 function wfIncrStats( $key, $count = 1 ) {
2472         global $wgStatsMethod;
2473
2474         $count = intval( $count );
2475
2476         if( $wgStatsMethod == 'udp' ) {
2477                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2478                 static $socket;
2479
2480                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2481
2482                 if ( !$socket ) {
2483                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2484                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2485                         socket_sendto(
2486                                 $socket,
2487                                 $statline,
2488                                 strlen( $statline ),
2489                                 0,
2490                                 $wgUDPProfilerHost,
2491                                 $wgUDPProfilerPort
2492                         );
2493                 }
2494                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2495                 wfSuppressWarnings();
2496                 socket_sendto(
2497                         $socket,
2498                         $statline,
2499                         strlen( $statline ),
2500                         0,
2501                         $wgUDPProfilerHost,
2502                         $wgUDPProfilerPort
2503                 );
2504                 wfRestoreWarnings();
2505         } elseif( $wgStatsMethod == 'cache' ) {
2506                 global $wgMemc;
2507                 $key = wfMemcKey( 'stats', $key );
2508                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2509                         $wgMemc->add( $key, $count );
2510                 }
2511         } else {
2512                 // Disabled
2513         }
2514 }
2515
2516 /**
2517  * @param $nr Mixed: the number to format
2518  * @param $acc Integer: the number of digits after the decimal point, default 2
2519  * @param $round Boolean: whether or not to round the value, default true
2520  * @return float
2521  */
2522 function wfPercent( $nr, $acc = 2, $round = true ) {
2523         $ret = sprintf( "%.${acc}f", $nr );
2524         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2525 }
2526
2527 /**
2528  * Find out whether or not a mixed variable exists in a string
2529  *
2530  * @param $needle String
2531  * @param $str String
2532  * @param $insensitive Boolean
2533  * @return Boolean
2534  */
2535 function in_string( $needle, $str, $insensitive = false ) {
2536         $func = 'strpos';
2537         if( $insensitive ) $func = 'stripos';
2538
2539         return $func( $str, $needle ) !== false;
2540 }
2541
2542 /**
2543  * Make a list item, used by various special pages
2544  *
2545  * @param $page String Page link
2546  * @param $details String Text between brackets
2547  * @param $oppositedm Boolean   Add the direction mark opposite to your
2548  *                                                              language, to display text properly
2549  * @return String
2550  */
2551 function wfSpecialList( $page, $details, $oppositedm = true ) {
2552         global $wgLang;
2553         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2554                 $wgLang->getDirMark();
2555         $details = $details ? $dirmark . " ($details)" : '';
2556         return $page . $details;
2557 }
2558
2559 /**
2560  * Safety wrapper around ini_get() for boolean settings.
2561  * The values returned from ini_get() are pre-normalized for settings
2562  * set via php.ini or php_flag/php_admin_flag... but *not*
2563  * for those set via php_value/php_admin_value.
2564  *
2565  * It's fairly common for people to use php_value instead of php_flag,
2566  * which can leave you with an 'off' setting giving a false positive
2567  * for code that just takes the ini_get() return value as a boolean.
2568  *
2569  * To make things extra interesting, setting via php_value accepts
2570  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2571  * Unrecognized values go false... again opposite PHP's own coercion
2572  * from string to bool.
2573  *
2574  * Luckily, 'properly' set settings will always come back as '0' or '1',
2575  * so we only have to worry about them and the 'improper' settings.
2576  *
2577  * I frickin' hate PHP... :P
2578  *
2579  * @param $setting String
2580  * @return Bool
2581  */
2582 function wfIniGetBool( $setting ) {
2583         $val = ini_get( $setting );
2584         // 'on' and 'true' can't have whitespace around them, but '1' can.
2585         return strtolower( $val ) == 'on'
2586                 || strtolower( $val ) == 'true'
2587                 || strtolower( $val ) == 'yes'
2588                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2589 }
2590
2591 /**
2592  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2593  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2594  *
2595  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2596  *                          should be omitted
2597  * @param $fileName String Name of the library, if not $extension.suffix
2598  * @return Bool - Whether or not the extension is loaded
2599  */
2600 function wfDl( $extension, $fileName = null ) {
2601         if( extension_loaded( $extension ) ) {
2602                 return true;
2603         }
2604
2605         $canDl = false;
2606         $sapi = php_sapi_name();
2607         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2608                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2609         {
2610                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2611                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2612         }
2613
2614         if( $canDl ) {
2615                 $fileName = $fileName ? $fileName : $extension;
2616                 if( wfIsWindows() ) {
2617                         $fileName = 'php_' . $fileName;
2618                 }
2619                 wfSuppressWarnings();
2620                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2621                 wfRestoreWarnings();
2622         }
2623         return extension_loaded( $extension );
2624 }
2625
2626 /**
2627  * Execute a shell command, with time and memory limits mirrored from the PHP
2628  * configuration if supported.
2629  * @param $cmd String Command line, properly escaped for shell.
2630  * @param &$retval optional, will receive the program's exit code.
2631  *                 (non-zero is usually failure)
2632  * @param $environ Array optional environment variables which should be
2633  *                 added to the executed command environment.
2634  * @return collected stdout as a string (trailing newlines stripped)
2635  */
2636 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2637         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2638
2639         static $disabled;
2640         if ( is_null( $disabled ) ) {
2641                 $disabled = false;
2642                 if( wfIniGetBool( 'safe_mode' ) ) {
2643                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2644                         $disabled = 'safemode';
2645                 } else {
2646                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2647                         $functions = array_map( 'trim', $functions );
2648                         $functions = array_map( 'strtolower', $functions );
2649                         if ( in_array( 'passthru', $functions ) ) {
2650                                 wfDebug( "passthru is in disabled_functions\n" );
2651                                 $disabled = 'passthru';
2652                         }
2653                 }
2654         }
2655         if ( $disabled ) {
2656                 $retval = 1;
2657                 return $disabled == 'safemode' ?
2658                         'Unable to run external programs in safe mode.' :
2659                         'Unable to run external programs, passthru() is disabled.';
2660         }
2661
2662         wfInitShellLocale();
2663
2664         $envcmd = '';
2665         foreach( $environ as $k => $v ) {
2666                 if ( wfIsWindows() ) {
2667                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2668                          * appear in the environment variable, so we must use carat escaping as documented in
2669                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2670                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2671                          * are listed there but doesn't appear to need it.
2672                          */
2673                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2674                 } else {
2675                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2676                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2677                          */
2678                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2679                 }
2680         }
2681         $cmd = $envcmd . $cmd;
2682
2683         if ( wfIsWindows() ) {
2684                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2685                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2686                 {
2687                         # Hack to work around PHP's flawed invocation of cmd.exe
2688                         # http://news.php.net/php.internals/21796
2689                         # Windows 9x doesn't accept any kind of quotes
2690                         $cmd = '"' . $cmd . '"';
2691                 }
2692         } elseif ( php_uname( 's' ) == 'Linux' ) {
2693                 $time = intval( $wgMaxShellTime );
2694                 $mem = intval( $wgMaxShellMemory );
2695                 $filesize = intval( $wgMaxShellFileSize );
2696
2697                 if ( $time > 0 && $mem > 0 ) {
2698                         $script = "$IP/bin/ulimit4.sh";
2699                         if ( is_executable( $script ) ) {
2700                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2701                         }
2702                 }
2703         }
2704         wfDebug( "wfShellExec: $cmd\n" );
2705
2706         $retval = 1; // error by default?
2707         ob_start();
2708         passthru( $cmd, $retval );
2709         $output = ob_get_contents();
2710         ob_end_clean();
2711
2712         if ( $retval == 127 ) {
2713                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2714         }
2715         return $output;
2716 }
2717
2718 /**
2719  * Workaround for http://bugs.php.net/bug.php?id=45132
2720  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2721  */
2722 function wfInitShellLocale() {
2723         static $done = false;
2724         if ( $done ) {
2725                 return;
2726         }
2727         $done = true;
2728         global $wgShellLocale;
2729         if ( !wfIniGetBool( 'safe_mode' ) ) {
2730                 putenv( "LC_CTYPE=$wgShellLocale" );
2731                 setlocale( LC_CTYPE, $wgShellLocale );
2732         }
2733 }
2734
2735 /**
2736  * This function works like "use VERSION" in Perl, the program will die with a
2737  * backtrace if the current version of PHP is less than the version provided
2738  *
2739  * This is useful for extensions which due to their nature are not kept in sync
2740  * with releases, and might depend on other versions of PHP than the main code
2741  *
2742  * Note: PHP might die due to parsing errors in some cases before it ever
2743  *       manages to call this function, such is life
2744  *
2745  * @see perldoc -f use
2746  *
2747  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2748  *                 a float
2749  */
2750 function wfUsePHP( $req_ver ) {
2751         $php_ver = PHP_VERSION;
2752
2753         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2754                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2755         }
2756 }
2757
2758 /**
2759  * This function works like "use VERSION" in Perl except it checks the version
2760  * of MediaWiki, the program will die with a backtrace if the current version
2761  * of MediaWiki is less than the version provided.
2762  *
2763  * This is useful for extensions which due to their nature are not kept in sync
2764  * with releases
2765  *
2766  * @see perldoc -f use
2767  *
2768  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2769  *                 a float
2770  */
2771 function wfUseMW( $req_ver ) {
2772         global $wgVersion;
2773
2774         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2775                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2776         }
2777 }
2778
2779 /**
2780  * Return the final portion of a pathname.
2781  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2782  * http://bugs.php.net/bug.php?id=33898
2783  *
2784  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2785  * We'll consider it so always, as we don't want \s in our Unix paths either.
2786  *
2787  * @param $path String
2788  * @param $suffix String: to remove if present
2789  * @return String
2790  */
2791 function wfBaseName( $path, $suffix = '' ) {
2792         $encSuffix = ( $suffix == '' )
2793                 ? ''
2794                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2795         $matches = array();
2796         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2797                 return $matches[1];
2798         } else {
2799                 return '';
2800         }
2801 }
2802
2803 /**
2804  * Generate a relative path name to the given file.
2805  * May explode on non-matching case-insensitive paths,
2806  * funky symlinks, etc.
2807  *
2808  * @param $path String: absolute destination path including target filename
2809  * @param $from String: Absolute source path, directory only
2810  * @return String
2811  */
2812 function wfRelativePath( $path, $from ) {
2813         // Normalize mixed input on Windows...
2814         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2815         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2816
2817         // Trim trailing slashes -- fix for drive root
2818         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2819         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2820
2821         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2822         $against = explode( DIRECTORY_SEPARATOR, $from );
2823
2824         if( $pieces[0] !== $against[0] ) {
2825                 // Non-matching Windows drive letters?
2826                 // Return a full path.
2827                 return $path;
2828         }
2829
2830         // Trim off common prefix
2831         while( count( $pieces ) && count( $against )
2832                 && $pieces[0] == $against[0] ) {
2833                 array_shift( $pieces );
2834                 array_shift( $against );
2835         }
2836
2837         // relative dots to bump us to the parent
2838         while( count( $against ) ) {
2839                 array_unshift( $pieces, '..' );
2840                 array_shift( $against );
2841         }
2842
2843         array_push( $pieces, wfBaseName( $path ) );
2844
2845         return implode( DIRECTORY_SEPARATOR, $pieces );
2846 }
2847
2848 /**
2849  * Do any deferred updates and clear the list
2850  *
2851  * @param $commit String: set to 'commit' to commit after every update to
2852  *                prevent lock contention
2853  */
2854 function wfDoUpdates( $commit = '' ) {
2855         global $wgDeferredUpdateList;
2856
2857         wfProfileIn( __METHOD__ );
2858
2859         // No need to get master connections in case of empty updates array
2860         if ( !count( $wgDeferredUpdateList ) ) {
2861                 wfProfileOut( __METHOD__ );
2862                 return;
2863         }
2864
2865         $doCommit = $commit == 'commit';
2866         if ( $doCommit ) {
2867                 $dbw = wfGetDB( DB_MASTER );
2868         }
2869
2870         foreach ( $wgDeferredUpdateList as $update ) {
2871                 $update->doUpdate();
2872
2873                 if ( $doCommit && $dbw->trxLevel() ) {
2874                         $dbw->commit();
2875                 }
2876         }
2877
2878         $wgDeferredUpdateList = array();
2879         wfProfileOut( __METHOD__ );
2880 }
2881
2882 /**
2883  * Convert an arbitrarily-long digit string from one numeric base
2884  * to another, optionally zero-padding to a minimum column width.
2885  *
2886  * Supports base 2 through 36; digit values 10-36 are represented
2887  * as lowercase letters a-z. Input is case-insensitive.
2888  *
2889  * @param $input String: of digits
2890  * @param $sourceBase Integer: 2-36
2891  * @param $destBase Integer: 2-36
2892  * @param $pad Integer: 1 or greater
2893  * @param $lowercase Boolean
2894  * @return String or false on invalid input
2895  */
2896 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2897         $input = strval( $input );
2898         if( $sourceBase < 2 ||
2899                 $sourceBase > 36 ||
2900                 $destBase < 2 ||
2901                 $destBase > 36 ||
2902                 $pad < 1 ||
2903                 $sourceBase != intval( $sourceBase ) ||
2904                 $destBase != intval( $destBase ) ||
2905                 $pad != intval( $pad ) ||
2906                 !is_string( $input ) ||
2907                 $input == '' ) {
2908                 return false;
2909         }
2910         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2911         $inDigits = array();
2912         $outChars = '';
2913
2914         // Decode and validate input string
2915         $input = strtolower( $input );
2916         for( $i = 0; $i < strlen( $input ); $i++ ) {
2917                 $n = strpos( $digitChars, $input[$i] );
2918                 if( $n === false || $n > $sourceBase ) {
2919                         return false;
2920                 }
2921                 $inDigits[] = $n;
2922         }
2923
2924         // Iterate over the input, modulo-ing out an output digit
2925         // at a time until input is gone.
2926         while( count( $inDigits ) ) {
2927                 $work = 0;
2928                 $workDigits = array();
2929
2930                 // Long division...
2931                 foreach( $inDigits as $digit ) {
2932                         $work *= $sourceBase;
2933                         $work += $digit;
2934
2935                         if( $work < $destBase ) {
2936                                 // Gonna need to pull another digit.
2937                                 if( count( $workDigits ) ) {
2938                                         // Avoid zero-padding; this lets us find
2939                                         // the end of the input very easily when
2940                                         // length drops to zero.
2941                                         $workDigits[] = 0;
2942                                 }
2943                         } else {
2944                                 // Finally! Actual division!
2945                                 $workDigits[] = intval( $work / $destBase );
2946
2947                                 // Isn't it annoying that most programming languages
2948                                 // don't have a single divide-and-remainder operator,
2949                                 // even though the CPU implements it that way?
2950                                 $work = $work % $destBase;
2951                         }
2952                 }
2953
2954                 // All that division leaves us with a remainder,
2955                 // which is conveniently our next output digit.
2956                 $outChars .= $digitChars[$work];
2957
2958                 // And we continue!
2959                 $inDigits = $workDigits;
2960         }
2961
2962         while( strlen( $outChars ) < $pad ) {
2963                 $outChars .= '0';
2964         }
2965
2966         return strrev( $outChars );
2967 }
2968
2969 /**
2970  * Create an object with a given name and an array of construct parameters
2971  *
2972  * @param $name String
2973  * @param $p Array: parameters
2974  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
2975  */
2976 function wfCreateObject( $name, $p ) {
2977         wfDeprecated( __FUNCTION__ );
2978         return MWFunction::newObj( $name, $p );
2979 }
2980
2981 function wfHttpOnlySafe() {
2982         global $wgHttpOnlyBlacklist;
2983
2984         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2985                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2986                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2987                                 return false;
2988                         }
2989                 }
2990         }
2991
2992         return true;
2993 }
2994
2995 /**
2996  * Initialise php session
2997  *
2998  * @param $sessionId Bool
2999  */
3000 function wfSetupSession( $sessionId = false ) {
3001         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3002                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3003         if( $wgSessionsInMemcached ) {
3004                 if ( !defined( 'MW_COMPILED' ) ) {
3005                         global $IP;
3006                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3007                 }
3008                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3009                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3010
3011                 // It's necessary to register a shutdown function to call session_write_close(),
3012                 // because by the time the request shutdown function for the session module is
3013                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3014                 // this way are called before object destruction.
3015                 register_shutdown_function( 'memsess_write_close' );
3016         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3017                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3018                 # hasn't already been set to the desired value (that causes errors)
3019                 ini_set( 'session.save_handler', $wgSessionHandler );
3020         }
3021         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3022         wfDebugLog( 'cookie',
3023                 'session_set_cookie_params: "' . implode( '", "',
3024                         array(
3025                                 0,
3026                                 $wgCookiePath,
3027                                 $wgCookieDomain,
3028                                 $wgCookieSecure,
3029                                 $httpOnlySafe ) ) . '"' );
3030         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3031         session_cache_limiter( 'private, must-revalidate' );
3032         if ( $sessionId ) {
3033                 session_id( $sessionId );
3034         }
3035         wfSuppressWarnings();
3036         session_start();
3037         wfRestoreWarnings();
3038 }
3039
3040 /**
3041  * Get an object from the precompiled serialized directory
3042  *
3043  * @param $name String
3044  * @return Mixed: the variable on success, false on failure
3045  */
3046 function wfGetPrecompiledData( $name ) {
3047         global $IP;
3048
3049         $file = "$IP/serialized/$name";
3050         if ( file_exists( $file ) ) {
3051                 $blob = file_get_contents( $file );
3052                 if ( $blob ) {
3053                         return unserialize( $blob );
3054                 }
3055         }
3056         return false;
3057 }
3058
3059 /**
3060  * Get a cache key
3061  *
3062  * @param varargs
3063  * @return String
3064  */
3065 function wfMemcKey( /*... */ ) {
3066         $args = func_get_args();
3067         $key = wfWikiID() . ':' . implode( ':', $args );
3068         $key = str_replace( ' ', '_', $key );
3069         return $key;
3070 }
3071
3072 /**
3073  * Get a cache key for a foreign DB
3074  *
3075  * @param $db String
3076  * @param $prefix String
3077  * @param varargs String
3078  * @return String
3079  */
3080 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3081         $args = array_slice( func_get_args(), 2 );
3082         if ( $prefix ) {
3083                 $key = "$db-$prefix:" . implode( ':', $args );
3084         } else {
3085                 $key = $db . ':' . implode( ':', $args );
3086         }
3087         return $key;
3088 }
3089
3090 /**
3091  * Get an ASCII string identifying this wiki
3092  * This is used as a prefix in memcached keys
3093  *
3094  * @return String
3095  */
3096 function wfWikiID() {
3097         global $wgDBprefix, $wgDBname;
3098         if ( $wgDBprefix ) {
3099                 return "$wgDBname-$wgDBprefix";
3100         } else {
3101                 return $wgDBname;
3102         }
3103 }
3104
3105 /**
3106  * Split a wiki ID into DB name and table prefix
3107  *
3108  * @param $wiki String
3109  * @param $bits String
3110  */
3111 function wfSplitWikiID( $wiki ) {
3112         $bits = explode( '-', $wiki, 2 );
3113         if ( count( $bits ) < 2 ) {
3114                 $bits[] = '';
3115         }
3116         return $bits;
3117 }
3118
3119 /**
3120  * Get a Database object.
3121  *
3122  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3123  *            master (for write queries), DB_SLAVE for potentially lagged read
3124  *            queries, or an integer >= 0 for a particular server.
3125  *
3126  * @param $groups Mixed: query groups. An array of group names that this query
3127  *                belongs to. May contain a single string if the query is only
3128  *                in one group.
3129  *
3130  * @param $wiki String: the wiki ID, or false for the current wiki
3131  *
3132  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3133  * will always return the same object, unless the underlying connection or load
3134  * balancer is manually destroyed.
3135  *
3136  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3137  * updater to ensure that a proper database is being updated.
3138  *
3139  * @return DatabaseBase
3140  */
3141 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3142         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3143 }
3144
3145 /**
3146  * Get a load balancer object.
3147  *
3148  * @param $wiki String: wiki ID, or false for the current wiki
3149  * @return LoadBalancer
3150  */
3151 function wfGetLB( $wiki = false ) {
3152         return wfGetLBFactory()->getMainLB( $wiki );
3153 }
3154
3155 /**
3156  * Get the load balancer factory object
3157  *
3158  * @return LBFactory
3159  */
3160 function &wfGetLBFactory() {
3161         return LBFactory::singleton();
3162 }
3163
3164 /**
3165  * Find a file.
3166  * Shortcut for RepoGroup::singleton()->findFile()
3167  *
3168  * @param $title String or Title object
3169  * @param $options Associative array of options:
3170  *     time:           requested time for an archived image, or false for the
3171  *                     current version. An image object will be returned which was
3172  *                     created at the specified time.
3173  *
3174  *     ignoreRedirect: If true, do not follow file redirects
3175  *
3176  *     private:        If true, return restricted (deleted) files if the current
3177  *                     user is allowed to view them. Otherwise, such files will not
3178  *                     be found.
3179  *
3180  *     bypassCache:    If true, do not use the process-local cache of File objects
3181  *
3182  * @return File, or false if the file does not exist
3183  */
3184 function wfFindFile( $title, $options = array() ) {
3185         return RepoGroup::singleton()->findFile( $title, $options );
3186 }
3187
3188 /**
3189  * Get an object referring to a locally registered file.
3190  * Returns a valid placeholder object if the file does not exist.
3191  *
3192  * @param $title Title or String
3193  * @return File, or null if passed an invalid Title
3194  */
3195 function wfLocalFile( $title ) {
3196         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3197 }
3198
3199 /**
3200  * Should low-performance queries be disabled?
3201  *
3202  * @return Boolean
3203  * @codeCoverageIgnore
3204  */
3205 function wfQueriesMustScale() {
3206         global $wgMiserMode;
3207         return $wgMiserMode
3208                 || ( SiteStats::pages() > 100000
3209                 && SiteStats::edits() > 1000000
3210                 && SiteStats::users() > 10000 );
3211 }
3212
3213 /**
3214  * Get the path to a specified script file, respecting file
3215  * extensions; this is a wrapper around $wgScriptExtension etc.
3216  *
3217  * @param $script String: script filename, sans extension
3218  * @return String
3219  */
3220 function wfScript( $script = 'index' ) {
3221         global $wgScriptPath, $wgScriptExtension;
3222         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3223 }
3224
3225 /**
3226  * Get the script URL.
3227  *
3228  * @return script URL
3229  */
3230 function wfGetScriptUrl() {
3231         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3232                 #
3233                 # as it was called, minus the query string.
3234                 #
3235                 # Some sites use Apache rewrite rules to handle subdomains,
3236                 # and have PHP set up in a weird way that causes PHP_SELF
3237                 # to contain the rewritten URL instead of the one that the
3238                 # outside world sees.
3239                 #
3240                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3241                 # provides containing the "before" URL.
3242                 return $_SERVER['SCRIPT_NAME'];
3243         } else {
3244                 return $_SERVER['URL'];
3245         }
3246 }
3247
3248 /**
3249  * Convenience function converts boolean values into "true"
3250  * or "false" (string) values
3251  *
3252  * @param $value Boolean
3253  * @return String
3254  */
3255 function wfBoolToStr( $value ) {
3256         return $value ? 'true' : 'false';
3257 }
3258
3259 /**
3260  * Load an extension messages file
3261  *
3262  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3263  * @codeCoverageIgnore
3264  */
3265 function wfLoadExtensionMessages() {
3266         wfDeprecated( __FUNCTION__ );
3267 }
3268
3269 /**
3270  * Get a platform-independent path to the null file, e.g. /dev/null
3271  *
3272  * @return string
3273  */
3274 function wfGetNull() {
3275         return wfIsWindows()
3276                 ? 'NUL'
3277                 : '/dev/null';
3278 }
3279
3280 /**
3281  * Throws a warning that $function is deprecated
3282  *
3283  * @param $function String
3284  * @return null
3285  */
3286 function wfDeprecated( $function ) {
3287         static $functionsWarned = array();
3288         if ( !isset( $functionsWarned[$function] ) ) {
3289                 $functionsWarned[$function] = true;
3290                 wfWarn( "Use of $function is deprecated.", 2 );
3291         }
3292 }
3293
3294 /**
3295  * Send a warning either to the debug log or in a PHP error depending on
3296  * $wgDevelopmentWarnings
3297  *
3298  * @param $msg String: message to send
3299  * @param $callerOffset Integer: number of items to go back in the backtrace to
3300  *        find the correct caller (1 = function calling wfWarn, ...)
3301  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3302  *        is true
3303  */
3304 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3305         global $wgDevelopmentWarnings;
3306
3307         $callers = wfDebugBacktrace();
3308         if ( isset( $callers[$callerOffset + 1] ) ) {
3309                 $callerfunc = $callers[$callerOffset + 1];
3310                 $callerfile = $callers[$callerOffset];
3311                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3312                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3313                 } else {
3314                         $file = '(internal function)';
3315                 }
3316                 $func = '';
3317                 if ( isset( $callerfunc['class'] ) ) {
3318                         $func .= $callerfunc['class'] . '::';
3319                 }
3320                 if ( isset( $callerfunc['function'] ) ) {
3321                         $func .= $callerfunc['function'];
3322                 }
3323                 $msg .= " [Called from $func in $file]";
3324         }
3325
3326         if ( $wgDevelopmentWarnings ) {
3327                 trigger_error( $msg, $level );
3328         } else {
3329                 wfDebug( "$msg\n" );
3330         }
3331 }
3332
3333 /**
3334  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3335  * and waiting for it to go down, this waits for the slaves to catch up to the
3336  * master position. Use this when updating very large numbers of rows, as
3337  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3338  * a no-op if there are no slaves.
3339  *
3340  * @param $maxLag Integer (deprecated)
3341  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3342  * @return null
3343  */
3344 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3345         $lb = wfGetLB( $wiki );
3346         // bug 27975 - Don't try to wait for slaves if there are none
3347         // Prevents permission error when getting master position
3348         if ( $lb->getServerCount() > 1 ) {
3349                 $dbw = $lb->getConnection( DB_MASTER );
3350                 $pos = $dbw->getMasterPos();
3351                 $lb->waitForAll( $pos );
3352         }
3353 }
3354
3355 /**
3356  * Used to be used for outputting text in the installer/updater
3357  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3358  */
3359 function wfOut( $s ) {
3360         wfDeprecated( __METHOD__ );
3361         global $wgCommandLineMode;
3362         if ( $wgCommandLineMode ) {
3363                 echo $s;
3364         } else {
3365                 echo htmlspecialchars( $s );
3366         }
3367         flush();
3368 }
3369
3370 /**
3371  * Count down from $n to zero on the terminal, with a one-second pause
3372  * between showing each number. For use in command-line scripts.
3373  * @codeCoverageIgnore
3374  */
3375 function wfCountDown( $n ) {
3376         for ( $i = $n; $i >= 0; $i-- ) {
3377                 if ( $i != $n ) {
3378                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3379                 }
3380                 echo $i;
3381                 flush();
3382                 if ( $i ) {
3383                         sleep( 1 );
3384                 }
3385         }
3386         echo "\n";
3387 }
3388
3389 /**
3390  * Generate a random 32-character hexadecimal token.
3391  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3392  *              characters before hashing.
3393  * @return string
3394  * @codeCoverageIgnore
3395  */
3396 function wfGenerateToken( $salt = '' ) {
3397         $salt = serialize( $salt );
3398         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3399 }
3400
3401 /**
3402  * Replace all invalid characters with -
3403  *
3404  * @param $name Mixed: filename to process
3405  * @return String
3406  */
3407 function wfStripIllegalFilenameChars( $name ) {
3408         global $wgIllegalFileChars;
3409         $name = wfBaseName( $name );
3410         $name = preg_replace(
3411                 "/[^" . Title::legalChars() . "]" .
3412                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3413                         "/",
3414                 '-',
3415                 $name
3416         );
3417         return $name;
3418 }
3419
3420 /**
3421  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3422  *
3423  * @return Integer value memory was set to.
3424  */
3425 function wfMemoryLimit() {
3426         global $wgMemoryLimit;
3427         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3428         if( $memlimit != -1 ) {
3429                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3430                 if( $conflimit == -1 ) {
3431                         wfDebug( "Removing PHP's memory limit\n" );
3432                         wfSuppressWarnings();
3433                         ini_set( 'memory_limit', $conflimit );
3434                         wfRestoreWarnings();
3435                         return $conflimit;
3436                 } elseif ( $conflimit > $memlimit ) {
3437                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3438                         wfSuppressWarnings();
3439                         ini_set( 'memory_limit', $conflimit );
3440                         wfRestoreWarnings();
3441                         return $conflimit;
3442                 }
3443         }
3444         return $memlimit;
3445 }
3446
3447 /**
3448  * Converts shorthand byte notation to integer form
3449  *
3450  * @param $string String
3451  * @return Integer
3452  */
3453 function wfShorthandToInteger( $string = '' ) {
3454         $string = trim( $string );
3455         if( $string === '' ) {
3456                 return -1;
3457         }
3458         $last = $string[strlen( $string ) - 1];
3459         $val = intval( $string );
3460         switch( $last ) {
3461                 case 'g':
3462                 case 'G':
3463                         $val *= 1024;
3464                         // break intentionally missing
3465                 case 'm':
3466                 case 'M':
3467                         $val *= 1024;
3468                         // break intentionally missing
3469                 case 'k':
3470                 case 'K':
3471                         $val *= 1024;
3472         }
3473
3474         return $val;
3475 }
3476
3477 /**
3478  * Get the normalised IETF language tag
3479  * See unit test for examples.
3480  *
3481  * @param $code String: The language code.
3482  * @return $langCode String: The language code which complying with BCP 47 standards.
3483  */
3484 function wfBCP47( $code ) {
3485         $codeSegment = explode( '-', $code );
3486         $codeBCP = array();
3487         foreach ( $codeSegment as $segNo => $seg ) {
3488                 if ( count( $codeSegment ) > 0 ) {
3489                         // when previous segment is x, it is a private segment and should be lc
3490                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3491                                 $codeBCP[$segNo] = strtolower( $seg );
3492                         // ISO 3166 country code
3493                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3494                                 $codeBCP[$segNo] = strtoupper( $seg );
3495                         // ISO 15924 script code
3496                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3497                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3498                         // Use lowercase for other cases
3499                         } else {
3500                                 $codeBCP[$segNo] = strtolower( $seg );
3501                         }
3502                 } else {
3503                 // Use lowercase for single segment
3504                         $codeBCP[$segNo] = strtolower( $seg );
3505                 }
3506         }
3507         $langCode = implode( '-', $codeBCP );
3508         return $langCode;
3509 }
3510
3511 /**
3512  * Get a cache object.
3513  *
3514  * @param $inputType integer Cache type, one the the CACHE_* constants.
3515  * @return BagOStuff
3516  */
3517 function wfGetCache( $inputType ) {
3518         return ObjectCache::getInstance( $inputType );
3519 }
3520
3521 /**
3522  * Get the main cache object
3523  *
3524  * @return BagOStuff
3525  */
3526 function wfGetMainCache() {
3527         global $wgMainCacheType;
3528         return ObjectCache::getInstance( $wgMainCacheType );
3529 }
3530
3531 /**
3532  * Get the cache object used by the message cache
3533  *
3534  * @return BagOStuff
3535  */
3536 function wfGetMessageCacheStorage() {
3537         global $wgMessageCacheType;
3538         return ObjectCache::getInstance( $wgMessageCacheType );
3539 }
3540
3541 /**
3542  * Get the cache object used by the parser cache
3543  *
3544  * @return BagOStuff
3545  */
3546 function wfGetParserCacheStorage() {
3547         global $wgParserCacheType;
3548         return ObjectCache::getInstance( $wgParserCacheType );
3549 }
3550
3551 /**
3552  * Call hook functions defined in $wgHooks
3553  *
3554  * @param $event String: event name
3555  * @param $args Array: parameters passed to hook functions
3556  * @return Boolean
3557  */
3558 function wfRunHooks( $event, $args = array() ) {
3559         return Hooks::run( $event, $args );
3560 }