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  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 441  *
 442  * @todo this won't work with current-path-relative URLs
 443  * like "subdir/foo.html", etc.
 444  *
 445  * @param $url String: either fully-qualified or a local path + query
 446  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the protocol to use if $url or $wgServer is protocol-relative
 447  * @return string Fully-qualified URL
 448  */
 449 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 450         global $wgServer, $wgCanonicalServer;
 451         $serverUrl = $defaultProto === PROTO_CANONICAL ? $wgCanonicalServer : $wgServer;
 452
 453         if ( $defaultProto === PROTO_CURRENT ) {
 454                 $defaultProto = WebRequest::detectProtocol() . '://';
 455         }
 456
 457         // Analyze $serverUrl to obtain its protocol
 458         $bits = wfParseUrl( $serverUrl );
 459         $serverHasProto = $bits && $bits['scheme'] != '';
 460
 461         if ( $defaultProto === PROTO_CANONICAL ) {
 462                 if ( $serverHasProto ) {
 463                         $defaultProto = $bits['scheme'] . '://';
 464                 } else {
 465                         // $wgCanonicalServer doesn't have a protocol. This really isn't supposed to happen
 466                         // Fall back to HTTP in this ridiculous case
 467                         $defaultProto = PROTO_HTTP;
 468                 }
 469         }
 470
 471         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 472
 473         if( substr( $url, 0, 2 ) == '//' ) {
 474                 return $defaultProtoWithoutSlashes . $url;
 475         } elseif( substr( $url, 0, 1 ) == '/' ) {
 476                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 477                 return ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 478         } else {
 479                 return $url;
 480         }
 481 }
 482
 483 /**
 484  * Returns a regular expression of url protocols
 485  *
 486  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 487  *        DO NOT USE this directy, use wfUrlProtocolsWithoutProtRel() instead
 488  * @return String
 489  */
 490 function wfUrlProtocols( $includeProtocolRelative = true ) {
 491         global $wgUrlProtocols;
 492
 493         // Cache return values separately based on $includeProtocolRelative
 494         static $withProtRel = null, $withoutProtRel = null;
 495         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 496         if ( !is_null( $cachedValue ) ) {
 497                 return $cachedValue;
 498         }
 499
 500         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 501         // with LocalSettings files from 1.5
 502         if ( is_array( $wgUrlProtocols ) ) {
 503                 $protocols = array();
 504                 foreach ( $wgUrlProtocols as $protocol ) {
 505                         // Filter out '//' if !$includeProtocolRelative
 506                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 507                                 $protocols[] = preg_quote( $protocol, '/' );
 508                         }
 509                 }
 510
 511                 $retval = implode( '|', $protocols );
 512         } else {
 513                 // Ignore $includeProtocolRelative in this case
 514                 // This case exists for pre-1.6 compatibility, and we can safely assume
 515                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 516                 // URLs weren't supported until 1.18
 517                 $retval = $wgUrlProtocols;
 518         }
 519
 520         // Cache return value
 521         if ( $includeProtocolRelative ) {
 522                 $withProtRel = $retval;
 523         } else {
 524                 $withoutProtRel = $retval;
 525         }
 526         return $retval;
 527 }
 528
 529 /**
 530  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 531  * you need a regex that matches all URL protocols but does not match protocol-
 532  * relative URLs
 533  */
 534 function wfUrlProtocolsWithoutProtRel() {
 535         return wfUrlProtocols( false );
 536 }
 537
 538 /**
 539  * parse_url() work-alike, but non-broken.  Differences:
 540  *
 541  * 1) Does not raise warnings on bad URLs (just returns false)
 542  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 543  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 544  *
 545  * @param $url String: a URL to parse
 546  * @return Array: bits of the URL in an associative array, per PHP docs
 547  */
 548 function wfParseUrl( $url ) {
 549         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 550
 551         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 552         // way to handle them is to just prepend 'http:' and strip the protocol out later
 553         $wasRelative = substr( $url, 0, 2 ) == '//';
 554         if ( $wasRelative ) {
 555                 $url = "http:$url";
 556         }
 557         wfSuppressWarnings();
 558         $bits = parse_url( $url );
 559         wfRestoreWarnings();
 560         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 561         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 562         if ( !$bits || !isset( $bits['scheme'] ) ) {
 563                 return false;
 564         }
 565
 566         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 567         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 568                 $bits['delimiter'] = '://';
 569         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 570                 $bits['delimiter'] = ':';
 571                 // parse_url detects for news: and mailto: the host part of an url as path
 572                 // We have to correct this wrong detection
 573                 if ( isset( $bits['path'] ) ) {
 574                         $bits['host'] = $bits['path'];
 575                         $bits['path'] = '';
 576                 }
 577         } else {
 578                 return false;
 579         }
 580
 581         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 582         if ( !isset( $bits['host'] ) ) {
 583                 $bits['host'] = '';
 584
 585                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 586                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 587                         $bits['path'] = '/' . $bits['path'];
 588                 }
 589         }
 590
 591         // If the URL was protocol-relative, fix scheme and delimiter
 592         if ( $wasRelative ) {
 593                 $bits['scheme'] = '';
 594                 $bits['delimiter'] = '//';
 595         }
 596         return $bits;
 597 }
 598
 599 /**
 600  * Make a URL index, appropriate for the el_index field of externallinks.
 601  *
 602  * @param $url String
 603  * @return String
 604  */
 605 function wfMakeUrlIndex( $url ) {
 606         $bits = wfParseUrl( $url );
 607
 608         // Reverse the labels in the hostname, convert to lower case
 609         // For emails reverse domainpart only
 610         if ( $bits['scheme'] == 'mailto' ) {
 611                 $mailparts = explode( '@', $bits['host'], 2 );
 612                 if ( count( $mailparts ) === 2 ) {
 613                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 614                 } else {
 615                         // No domain specified, don't mangle it
 616                         $domainpart = '';
 617                 }
 618                 $reversedHost = $domainpart . '@' . $mailparts[0];
 619         } else {
 620                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 621         }
 622         // Add an extra dot to the end
 623         // Why? Is it in wrong place in mailto links?
 624         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 625                 $reversedHost .= '.';
 626         }
 627         // Reconstruct the pseudo-URL
 628         $prot = $bits['scheme'];
 629         $index = $prot . $bits['delimiter'] . $reversedHost;
 630         // Leave out user and password. Add the port, path, query and fragment
 631         if ( isset( $bits['port'] ) ) {
 632                 $index .= ':' . $bits['port'];
 633         }
 634         if ( isset( $bits['path'] ) ) {
 635                 $index .= $bits['path'];
 636         } else {
 637                 $index .= '/';
 638         }
 639         if ( isset( $bits['query'] ) ) {
 640                 $index .= '?' . $bits['query'];
 641         }
 642         if ( isset( $bits['fragment'] ) ) {
 643                 $index .= '#' . $bits['fragment'];
 644         }
 645         return $index;
 646 }
 647
 648 /**
 649  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 650  * In normal operation this is a NOP.
 651  *
 652  * Controlling globals:
 653  * $wgDebugLogFile - points to the log file
 654  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 655  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 656  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 657  *
 658  * @param $text String
 659  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 660  */
 661 function wfDebug( $text, $logonly = false ) {
 662         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 663         global $wgDebugLogPrefix, $wgShowDebug;
 664
 665         static $cache = array(); // Cache of unoutputted messages
 666         $text = wfDebugTimer() . $text;
 667
 668         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 669                 return;
 670         }
 671
 672         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 673                 $cache[] = $text;
 674
 675                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 676                         // add the message and any cached messages to the output
 677                         array_map( array( $wgOut, 'debug' ), $cache );
 678                         $cache = array();
 679                 }
 680         }
 681         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 682                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 683                         # Strip unprintables; they can switch terminal modes when binary data
 684                         # gets dumped, which is pretty annoying.
 685                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 686                         $text = $wgDebugLogPrefix . $text;
 687                         wfErrorLog( $text, $wgDebugLogFile );
 688                 }
 689         }
 690 }
 691
 692 /**
 693  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 694  */
 695 function wfIsDebugRawPage() {
 696         static $cache;
 697         if ( $cache !== null ) {
 698                 return $cache;
 699         }
 700         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 701         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 702                 || (
 703                         isset( $_SERVER['SCRIPT_NAME'] )
 704                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 705                 ) )
 706         {
 707                 $cache = true;
 708         } else {
 709                 $cache = false;
 710         }
 711         return $cache;
 712 }
 713
 714 /**
 715  * Get microsecond timestamps for debug logs
 716  *
 717  * @return string
 718  */
 719 function wfDebugTimer() {
 720         global $wgDebugTimestamps;
 721         if ( !$wgDebugTimestamps ) {
 722                 return '';
 723         }
 724         static $start = null;
 725
 726         if ( $start === null ) {
 727                 $start = microtime( true );
 728                 $prefix = "\n$start";
 729         } else {
 730                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 731         }
 732
 733         return $prefix . '  ';
 734 }
 735
 736 /**
 737  * Send a line giving PHP memory usage.
 738  *
 739  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 740  */
 741 function wfDebugMem( $exact = false ) {
 742         $mem = memory_get_usage();
 743         if( !$exact ) {
 744                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 745         } else {
 746                 $mem .= ' bytes';
 747         }
 748         wfDebug( "Memory usage: $mem\n" );
 749 }
 750
 751 /**
 752  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 753  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 754  *
 755  * @param $logGroup String
 756  * @param $text String
 757  * @param $public Bool: whether to log the event in the public log if no private
 758  *                     log file is specified, (default true)
 759  */
 760 function wfDebugLog( $logGroup, $text, $public = true ) {
 761         global $wgDebugLogGroups, $wgShowHostnames;
 762         $text = trim( $text ) . "\n";
 763         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 764                 $time = wfTimestamp( TS_DB );
 765                 $wiki = wfWikiID();
 766                 if ( $wgShowHostnames ) {
 767                         $host = wfHostname();
 768                 } else {
 769                         $host = '';
 770                 }
 771                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 772                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 773                 }
 774         } elseif ( $public === true ) {
 775                 wfDebug( $text, true );
 776         }
 777 }
 778
 779 /**
 780  * Log for database errors
 781  *
 782  * @param $text String: database error message.
 783  */
 784 function wfLogDBError( $text ) {
 785         global $wgDBerrorLog, $wgDBname;
 786         if ( $wgDBerrorLog ) {
 787                 $host = trim(`hostname`);
 788                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 789                 wfErrorLog( $text, $wgDBerrorLog );
 790         }
 791 }
 792
 793 /**
 794  * Log to a file without getting "file size exceeded" signals.
 795  *
 796  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 797  * send lines to the specified port, prefixed by the specified prefix and a space.
 798  *
 799  * @param $text String
 800  * @param $file String filename
 801  */
 802 function wfErrorLog( $text, $file ) {
 803         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 804                 # Needs the sockets extension
 805                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 806                         // IPv6 bracketed host
 807                         $host = $m[2];
 808                         $port = intval( $m[3] );
 809                         $prefix = isset( $m[4] ) ? $m[4] : false;
 810                         $domain = AF_INET6;
 811                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 812                         $host = $m[2];
 813                         if ( !IP::isIPv4( $host ) ) {
 814                                 $host = gethostbyname( $host );
 815                         }
 816                         $port = intval( $m[3] );
 817                         $prefix = isset( $m[4] ) ? $m[4] : false;
 818                         $domain = AF_INET;
 819                 } else {
 820                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 821                 }
 822
 823                 // Clean it up for the multiplexer
 824                 if ( strval( $prefix ) !== '' ) {
 825                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 826
 827                         // Limit to 64KB
 828                         if ( strlen( $text ) > 65534 ) {
 829                                 $text = substr( $text, 0, 65534 );
 830                         }
 831
 832                         if ( substr( $text, -1 ) != "\n" ) {
 833                                 $text .= "\n";
 834                         }
 835                 } elseif ( strlen( $text ) > 65535 ) {
 836                         $text = substr( $text, 0, 65535 );
 837                 }
 838
 839                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 840                 if ( !$sock ) {
 841                         return;
 842                 }
 843                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 844                 socket_close( $sock );
 845         } else {
 846                 wfSuppressWarnings();
 847                 $exists = file_exists( $file );
 848                 $size = $exists ? filesize( $file ) : false;
 849                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 850                         file_put_contents( $file, $text, FILE_APPEND );
 851                 }
 852                 wfRestoreWarnings();
 853         }
 854 }
 855
 856 /**
 857  * @todo document
 858  */
 859 function wfLogProfilingData() {
 860         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 861         global $wgProfileLimit, $wgUser;
 862
 863         $profiler = Profiler::instance();
 864
 865         # Profiling must actually be enabled...
 866         if ( $profiler->isStub() ) {
 867                 return;
 868         }
 869
 870         // Get total page request time and only show pages that longer than
 871         // $wgProfileLimit time (default is 0)
 872         $now = wfTime();
 873         $elapsed = $now - $wgRequestTime;
 874         if ( $elapsed <= $wgProfileLimit ) {
 875                 return;
 876         }
 877
 878         $profiler->logData();
 879
 880         // Check whether this should be logged in the debug file.
 881         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 882                 return;
 883         }
 884
 885         $forward = '';
 886         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 887                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 888         }
 889         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 890                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 891         }
 892         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 893                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 894         }
 895         if ( $forward ) {
 896                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 897         }
 898         // Don't load $wgUser at this late stage just for statistics purposes
 899         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 900         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 901                 $forward .= ' anon';
 902         }
 903         $log = sprintf( "%s\t%04.3f\t%s\n",
 904                 gmdate( 'YmdHis' ), $elapsed,
 905                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 906
 907         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 908 }
 909
 910 /**
 911  * Check if the wiki read-only lock file is present. This can be used to lock
 912  * off editing functions, but doesn't guarantee that the database will not be
 913  * modified.
 914  *
 915  * @return bool
 916  */
 917 function wfReadOnly() {
 918         global $wgReadOnlyFile, $wgReadOnly;
 919
 920         if ( !is_null( $wgReadOnly ) ) {
 921                 return (bool)$wgReadOnly;
 922         }
 923         if ( $wgReadOnlyFile == '' ) {
 924                 return false;
 925         }
 926         // Set $wgReadOnly for faster access next time
 927         if ( is_file( $wgReadOnlyFile ) ) {
 928                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 929         } else {
 930                 $wgReadOnly = false;
 931         }
 932         return (bool)$wgReadOnly;
 933 }
 934
 935 function wfReadOnlyReason() {
 936         global $wgReadOnly;
 937         wfReadOnly();
 938         return $wgReadOnly;
 939 }
 940
 941 /**
 942  * Return a Language object from $langcode
 943  *
 944  * @param $langcode Mixed: either:
 945  *                  - a Language object
 946  *                  - code of the language to get the message for, if it is
 947  *                    a valid code create a language for that language, if
 948  *                    it is a string but not a valid code then make a basic
 949  *                    language object
 950  *                  - a boolean: if it's false then use the current users
 951  *                    language (as a fallback for the old parameter
 952  *                    functionality), or if it is true then use the wikis
 953  * @return Language object
 954  */
 955 function wfGetLangObj( $langcode = false ) {
 956         # Identify which language to get or create a language object for.
 957         # Using is_object here due to Stub objects.
 958         if( is_object( $langcode ) ) {
 959                 # Great, we already have the object (hopefully)!
 960                 return $langcode;
 961         }
 962
 963         global $wgContLang, $wgLanguageCode;
 964         if( $langcode === true || $langcode === $wgLanguageCode ) {
 965                 # $langcode is the language code of the wikis content language object.
 966                 # or it is a boolean and value is true
 967                 return $wgContLang;
 968         }
 969
 970         global $wgLang;
 971         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 972                 # $langcode is the language code of user language object.
 973                 # or it was a boolean and value is false
 974                 return $wgLang;
 975         }
 976
 977         $validCodes = array_keys( Language::getLanguageNames() );
 978         if( in_array( $langcode, $validCodes ) ) {
 979                 # $langcode corresponds to a valid language.
 980                 return Language::factory( $langcode );
 981         }
 982
 983         # $langcode is a string, but not a valid language code; use content language.
 984         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 985         return $wgContLang;
 986 }
 987
 988 /**
 989  * Old function when $wgBetterDirectionality existed
 990  * Removed in core, kept in extensions for backwards compat.
 991  *
 992  * @deprecated since 1.18
 993  * @return Language
 994  */
 995 function wfUILang() {
 996         global $wgLang;
 997         return $wgLang;
 998 }
 999
1000 /**
1001  * This is the new function for getting translated interface messages.
1002  * See the Message class for documentation how to use them.
1003  * The intention is that this function replaces all old wfMsg* functions.
1004  * @param $key \string Message key.
1005  * Varargs: normal message parameters.
1006  * @return Message
1007  * @since 1.17
1008  */
1009 function wfMessage( $key /*...*/) {
1010         $params = func_get_args();
1011         array_shift( $params );
1012         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1013                 $params = $params[0];
1014         }
1015         return new Message( $key, $params );
1016 }
1017
1018 /**
1019  * This function accepts multiple message keys and returns a message instance
1020  * for the first message which is non-empty. If all messages are empty then an
1021  * instance of the first message key is returned.
1022  * @param varargs: message keys
1023  * @return Message
1024  * @since 1.18
1025  */
1026 function wfMessageFallback( /*...*/ ) {
1027         $args = func_get_args();
1028         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1029 }
1030
1031 /**
1032  * Get a message from anywhere, for the current user language.
1033  *
1034  * Use wfMsgForContent() instead if the message should NOT
1035  * change depending on the user preferences.
1036  *
1037  * @param $key String: lookup key for the message, usually
1038  *    defined in languages/Language.php
1039  *
1040  * Parameters to the message, which can be used to insert variable text into
1041  * it, can be passed to this function in the following formats:
1042  * - One per argument, starting at the second parameter
1043  * - As an array in the second parameter
1044  * These are not shown in the function definition.
1045  *
1046  * @return String
1047  */
1048 function wfMsg( $key ) {
1049         $args = func_get_args();
1050         array_shift( $args );
1051         return wfMsgReal( $key, $args );
1052 }
1053
1054 /**
1055  * Same as above except doesn't transform the message
1056  *
1057  * @param $key String
1058  * @return String
1059  */
1060 function wfMsgNoTrans( $key ) {
1061         $args = func_get_args();
1062         array_shift( $args );
1063         return wfMsgReal( $key, $args, true, false, false );
1064 }
1065
1066 /**
1067  * Get a message from anywhere, for the current global language
1068  * set with $wgLanguageCode.
1069  *
1070  * Use this if the message should NOT change dependent on the
1071  * language set in the user's preferences. This is the case for
1072  * most text written into logs, as well as link targets (such as
1073  * the name of the copyright policy page). Link titles, on the
1074  * other hand, should be shown in the UI language.
1075  *
1076  * Note that MediaWiki allows users to change the user interface
1077  * language in their preferences, but a single installation
1078  * typically only contains content in one language.
1079  *
1080  * Be wary of this distinction: If you use wfMsg() where you should
1081  * use wfMsgForContent(), a user of the software may have to
1082  * customize potentially hundreds of messages in
1083  * order to, e.g., fix a link in every possible language.
1084  *
1085  * @param $key String: lookup key for the message, usually
1086  *     defined in languages/Language.php
1087  * @return String
1088  */
1089 function wfMsgForContent( $key ) {
1090         global $wgForceUIMsgAsContentMsg;
1091         $args = func_get_args();
1092         array_shift( $args );
1093         $forcontent = true;
1094         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1095                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1096         {
1097                 $forcontent = false;
1098         }
1099         return wfMsgReal( $key, $args, true, $forcontent );
1100 }
1101
1102 /**
1103  * Same as above except doesn't transform the message
1104  *
1105  * @param $key String
1106  * @return String
1107  */
1108 function wfMsgForContentNoTrans( $key ) {
1109         global $wgForceUIMsgAsContentMsg;
1110         $args = func_get_args();
1111         array_shift( $args );
1112         $forcontent = true;
1113         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1114                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1115         {
1116                 $forcontent = false;
1117         }
1118         return wfMsgReal( $key, $args, true, $forcontent, false );
1119 }
1120
1121 /**
1122  * Really get a message
1123  *
1124  * @param $key String: key to get.
1125  * @param $args
1126  * @param $useDB Boolean
1127  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1128  * @param $transform Boolean: Whether or not to transform the message.
1129  * @return String: the requested message.
1130  */
1131 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1132         wfProfileIn( __METHOD__ );
1133         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1134         $message = wfMsgReplaceArgs( $message, $args );
1135         wfProfileOut( __METHOD__ );
1136         return $message;
1137 }
1138
1139 /**
1140  * Fetch a message string value, but don't replace any keys yet.
1141  *
1142  * @param $key String
1143  * @param $useDB Bool
1144  * @param $langCode String: Code of the language to get the message for, or
1145  *                  behaves as a content language switch if it is a boolean.
1146  * @param $transform Boolean: whether to parse magic words, etc.
1147  * @return string
1148  */
1149 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1150         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1151
1152         $cache = MessageCache::singleton();
1153         $message = $cache->get( $key, $useDB, $langCode );
1154         if( $message === false ) {
1155                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1156         } elseif ( $transform ) {
1157                 $message = $cache->transform( $message );
1158         }
1159         return $message;
1160 }
1161
1162 /**
1163  * Replace message parameter keys on the given formatted output.
1164  *
1165  * @param $message String
1166  * @param $args Array
1167  * @return string
1168  * @private
1169  */
1170 function wfMsgReplaceArgs( $message, $args ) {
1171         # Fix windows line-endings
1172         # Some messages are split with explode("\n", $msg)
1173         $message = str_replace( "\r", '', $message );
1174
1175         // Replace arguments
1176         if ( count( $args ) ) {
1177                 if ( is_array( $args[0] ) ) {
1178                         $args = array_values( $args[0] );
1179                 }
1180                 $replacementKeys = array();
1181                 foreach( $args as $n => $param ) {
1182                         $replacementKeys['$' . ( $n + 1 )] = $param;
1183                 }
1184                 $message = strtr( $message, $replacementKeys );
1185         }
1186
1187         return $message;
1188 }
1189
1190 /**
1191  * Return an HTML-escaped version of a message.
1192  * Parameter replacements, if any, are done *after* the HTML-escaping,
1193  * so parameters may contain HTML (eg links or form controls). Be sure
1194  * to pre-escape them if you really do want plaintext, or just wrap
1195  * the whole thing in htmlspecialchars().
1196  *
1197  * @param $key String
1198  * @param string ... parameters
1199  * @return string
1200  */
1201 function wfMsgHtml( $key ) {
1202         $args = func_get_args();
1203         array_shift( $args );
1204         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1205 }
1206
1207 /**
1208  * Return an HTML version of message
1209  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1210  * so parameters may contain HTML (eg links or form controls). Be sure
1211  * to pre-escape them if you really do want plaintext, or just wrap
1212  * the whole thing in htmlspecialchars().
1213  *
1214  * @param $key String
1215  * @param string ... parameters
1216  * @return string
1217  */
1218 function wfMsgWikiHtml( $key ) {
1219         $args = func_get_args();
1220         array_shift( $args );
1221         return wfMsgReplaceArgs(
1222                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1223                 /* can't be set to false */ true, /* interface */ true )->getText(),
1224                 $args );
1225 }
1226
1227 /**
1228  * Returns message in the requested format
1229  * @param $key String: key of the message
1230  * @param $options Array: processing rules. Can take the following options:
1231  *   <i>parse</i>: parses wikitext to HTML
1232  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1233  *       p's added by parser or tidy
1234  *   <i>escape</i>: filters message through htmlspecialchars
1235  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1236  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1237  *   <i>parsemag</i>: transform the message using magic phrases
1238  *   <i>content</i>: fetch message for content language instead of interface
1239  * Also can accept a single associative argument, of the form 'language' => 'xx':
1240  *   <i>language</i>: Language object or language code to fetch message for
1241  *       (overriden by <i>content</i>).
1242  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1243  *
1244  * @return String
1245  */
1246 function wfMsgExt( $key, $options ) {
1247         $args = func_get_args();
1248         array_shift( $args );
1249         array_shift( $args );
1250         $options = (array)$options;
1251
1252         foreach( $options as $arrayKey => $option ) {
1253                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1254                         # An unknown index, neither numeric nor "language"
1255                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1256                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1257                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1258                 'replaceafter', 'parsemag', 'content' ) ) ) {
1259                         # A numeric index with unknown value
1260                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1261                 }
1262         }
1263
1264         if( in_array( 'content', $options, true ) ) {
1265                 $forContent = true;
1266                 $langCode = true;
1267                 $langCodeObj = null;
1268         } elseif( array_key_exists( 'language', $options ) ) {
1269                 $forContent = false;
1270                 $langCode = wfGetLangObj( $options['language'] );
1271                 $langCodeObj = $langCode;
1272         } else {
1273                 $forContent = false;
1274                 $langCode = false;
1275                 $langCodeObj = null;
1276         }
1277
1278         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1279
1280         if( !in_array( 'replaceafter', $options, true ) ) {
1281                 $string = wfMsgReplaceArgs( $string, $args );
1282         }
1283
1284         $messageCache = MessageCache::singleton();
1285         if( in_array( 'parse', $options, true ) ) {
1286                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1287         } elseif ( in_array( 'parseinline', $options, true ) ) {
1288                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1289                 $m = array();
1290                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1291                         $string = $m[1];
1292                 }
1293         } elseif ( in_array( 'parsemag', $options, true ) ) {
1294                 $string = $messageCache->transform( $string,
1295                                 !$forContent, $langCodeObj );
1296         }
1297
1298         if ( in_array( 'escape', $options, true ) ) {
1299                 $string = htmlspecialchars ( $string );
1300         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1301                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1302         }
1303
1304         if( in_array( 'replaceafter', $options, true ) ) {
1305                 $string = wfMsgReplaceArgs( $string, $args );
1306         }
1307
1308         return $string;
1309 }
1310
1311 /**
1312  * Since wfMsg() and co suck, they don't return false if the message key they
1313  * looked up didn't exist but a XHTML string, this function checks for the
1314  * nonexistance of messages by checking the MessageCache::get() result directly.
1315  *
1316  * @param $key      String: the message key looked up
1317  * @return Boolean True if the message *doesn't* exist.
1318  */
1319 function wfEmptyMsg( $key ) {
1320         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1321 }
1322
1323 /**
1324  * Throw a debugging exception. This function previously once exited the process,
1325  * but now throws an exception instead, with similar results.
1326  *
1327  * @param $msg String: message shown when dieing.
1328  */
1329 function wfDebugDieBacktrace( $msg = '' ) {
1330         throw new MWException( $msg );
1331 }
1332
1333 /**
1334  * Fetch server name for use in error reporting etc.
1335  * Use real server name if available, so we know which machine
1336  * in a server farm generated the current page.
1337  *
1338  * @return string
1339  */
1340 function wfHostname() {
1341         static $host;
1342         if ( is_null( $host ) ) {
1343                 if ( function_exists( 'posix_uname' ) ) {
1344                         // This function not present on Windows
1345                         $uname = posix_uname();
1346                 } else {
1347                         $uname = false;
1348                 }
1349                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1350                         $host = $uname['nodename'];
1351                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1352                         # Windows computer name
1353                         $host = getenv( 'COMPUTERNAME' );
1354                 } else {
1355                         # This may be a virtual server.
1356                         $host = $_SERVER['SERVER_NAME'];
1357                 }
1358         }
1359         return $host;
1360 }
1361
1362 /**
1363  * Returns a HTML comment with the elapsed time since request.
1364  * This method has no side effects.
1365  *
1366  * @return string
1367  */
1368 function wfReportTime() {
1369         global $wgRequestTime, $wgShowHostnames;
1370
1371         $now = wfTime();
1372         $elapsed = $now - $wgRequestTime;
1373
1374         return $wgShowHostnames
1375                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1376                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1377 }
1378
1379 /**
1380  * Safety wrapper for debug_backtrace().
1381  *
1382  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1383  * murky circumstances, which may be triggered in part by stub objects
1384  * or other fancy talkin'.
1385  *
1386  * Will return an empty array if Zend Optimizer is detected or if
1387  * debug_backtrace is disabled, otherwise the output from
1388  * debug_backtrace() (trimmed).
1389  *
1390  * @return array of backtrace information
1391  */
1392 function wfDebugBacktrace( $limit = 0 ) {
1393         static $disabled = null;
1394
1395         if( extension_loaded( 'Zend Optimizer' ) ) {
1396                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1397                 return array();
1398         }
1399
1400         if ( is_null( $disabled ) ) {
1401                 $disabled = false;
1402                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1403                 $functions = array_map( 'trim', $functions );
1404                 $functions = array_map( 'strtolower', $functions );
1405                 if ( in_array( 'debug_backtrace', $functions ) ) {
1406                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1407                         $disabled = true;
1408                 }
1409         }
1410         if ( $disabled ) {
1411                 return array();
1412         }
1413
1414         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1415                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1416         } else {
1417                 return array_slice( debug_backtrace(), 1 );
1418         }
1419 }
1420
1421 /**
1422  * Get a debug backtrace as a string
1423  *
1424  * @return string
1425  */
1426 function wfBacktrace() {
1427         global $wgCommandLineMode;
1428
1429         if ( $wgCommandLineMode ) {
1430                 $msg = '';
1431         } else {
1432                 $msg = "<ul>\n";
1433         }
1434         $backtrace = wfDebugBacktrace();
1435         foreach( $backtrace as $call ) {
1436                 if( isset( $call['file'] ) ) {
1437                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1438                         $file = $f[count( $f ) - 1];
1439                 } else {
1440                         $file = '-';
1441                 }
1442                 if( isset( $call['line'] ) ) {
1443                         $line = $call['line'];
1444                 } else {
1445                         $line = '-';
1446                 }
1447                 if ( $wgCommandLineMode ) {
1448                         $msg .= "$file line $line calls ";
1449                 } else {
1450                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1451                 }
1452                 if( !empty( $call['class'] ) ) {
1453                         $msg .= $call['class'] . $call['type'];
1454                 }
1455                 $msg .= $call['function'] . '()';
1456
1457                 if ( $wgCommandLineMode ) {
1458                         $msg .= "\n";
1459                 } else {
1460                         $msg .= "</li>\n";
1461                 }
1462         }
1463         if ( $wgCommandLineMode ) {
1464                 $msg .= "\n";
1465         } else {
1466                 $msg .= "</ul>\n";
1467         }
1468
1469         return $msg;
1470 }
1471
1472 /**
1473  * Get the name of the function which called this function
1474  *
1475  * @param $level Int
1476  * @return Bool|string
1477  */
1478 function wfGetCaller( $level = 2 ) {
1479         $backtrace = wfDebugBacktrace( $level );
1480         if ( isset( $backtrace[$level] ) ) {
1481                 return wfFormatStackFrame( $backtrace[$level] );
1482         } else {
1483                 $caller = 'unknown';
1484         }
1485         return $caller;
1486 }
1487
1488 /**
1489  * Return a string consisting of callers in the stack. Useful sometimes
1490  * for profiling specific points.
1491  *
1492  * @param $limit The maximum depth of the stack frame to return, or false for
1493  *               the entire stack.
1494  * @return String
1495  */
1496 function wfGetAllCallers( $limit = 3 ) {
1497         $trace = array_reverse( wfDebugBacktrace() );
1498         if ( !$limit || $limit > count( $trace ) - 1 ) {
1499                 $limit = count( $trace ) - 1;
1500         }
1501         $trace = array_slice( $trace, -$limit - 1, $limit );
1502         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1503 }
1504
1505 /**
1506  * Return a string representation of frame
1507  *
1508  * @param $frame Array
1509  * @return Bool
1510  */
1511 function wfFormatStackFrame( $frame ) {
1512         return isset( $frame['class'] ) ?
1513                 $frame['class'] . '::' . $frame['function'] :
1514                 $frame['function'];
1515 }
1516
1517
1518 /* Some generic result counters, pulled out of SearchEngine */
1519
1520
1521 /**
1522  * @todo document
1523  *
1524  * @param $offset Int
1525  * @param $limit Int
1526  * @return String
1527  */
1528 function wfShowingResults( $offset, $limit ) {
1529         global $wgLang;
1530         return wfMsgExt(
1531                 'showingresults',
1532                 array( 'parseinline' ),
1533                 $wgLang->formatNum( $limit ),
1534                 $wgLang->formatNum( $offset + 1 )
1535         );
1536 }
1537
1538 /**
1539  * Generate (prev x| next x) (20|50|100...) type links for paging
1540  *
1541  * @param $offset String
1542  * @param $limit Integer
1543  * @param $link String
1544  * @param $query String: optional URL query parameter string
1545  * @param $atend Bool: optional param for specified if this is the last page
1546  * @return String
1547  */
1548 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1549         global $wgLang;
1550         $fmtLimit = $wgLang->formatNum( $limit );
1551         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1552         # Get prev/next link display text
1553         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1554         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1555         # Get prev/next link title text
1556         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1557         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1558         # Fetch the title object
1559         if( is_object( $link ) ) {
1560                 $title =& $link;
1561         } else {
1562                 $title = Title::newFromText( $link );
1563                 if( is_null( $title ) ) {
1564                         return false;
1565                 }
1566         }
1567         # Make 'previous' link
1568         if( 0 != $offset ) {
1569                 $po = $offset - $limit;
1570                 $po = max( $po, 0 );
1571                 $q = "limit={$limit}&offset={$po}";
1572                 if( $query != '' ) {
1573                         $q .= '&' . $query;
1574                 }
1575                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1576         } else {
1577                 $plink = $prev;
1578         }
1579         # Make 'next' link
1580         $no = $offset + $limit;
1581         $q = "limit={$limit}&offset={$no}";
1582         if( $query != '' ) {
1583                 $q .= '&' . $query;
1584         }
1585         if( $atend ) {
1586                 $nlink = $next;
1587         } else {
1588                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1589         }
1590         # Make links to set number of items per page
1591         $nums = $wgLang->pipeList( array(
1592                 wfNumLink( $offset, 20, $title, $query ),
1593                 wfNumLink( $offset, 50, $title, $query ),
1594                 wfNumLink( $offset, 100, $title, $query ),
1595                 wfNumLink( $offset, 250, $title, $query ),
1596                 wfNumLink( $offset, 500, $title, $query )
1597         ) );
1598         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1599 }
1600
1601 /**
1602  * Generate links for (20|50|100...) items-per-page links
1603  *
1604  * @param $offset String
1605  * @param $limit Integer
1606  * @param $title Title
1607  * @param $query String: optional URL query parameter string
1608  */
1609 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1610         global $wgLang;
1611         if( $query == '' ) {
1612                 $q = '';
1613         } else {
1614                 $q = $query.'&';
1615         }
1616         $q .= "limit={$limit}&offset={$offset}";
1617         $fmtLimit = $wgLang->formatNum( $limit );
1618         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1619         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1620         return $s;
1621 }
1622
1623 /**
1624  * @todo document
1625  * @todo FIXME: We may want to blacklist some broken browsers
1626  *
1627  * @param $force Bool
1628  * @return bool Whereas client accept gzip compression
1629  */
1630 function wfClientAcceptsGzip( $force = false ) {
1631         static $result = null;
1632         if ( $result === null || $force ) {
1633                 $result = false;
1634                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1635                         # @todo FIXME: We may want to blacklist some broken browsers
1636                         $m = array();
1637                         if( preg_match(
1638                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1639                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1640                                 $m )
1641                         )
1642                         {
1643                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1644                                         $result = false;
1645                                         return $result;
1646                                 }
1647                                 wfDebug( " accepts gzip\n" );
1648                                 $result = true;
1649                         }
1650                 }
1651         }
1652         return $result;
1653 }
1654
1655 /**
1656  * Obtain the offset and limit values from the request string;
1657  * used in special pages
1658  *
1659  * @param $deflimit Int default limit if none supplied
1660  * @param $optionname String Name of a user preference to check against
1661  * @return array
1662  *
1663  */
1664 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1665         global $wgRequest;
1666         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1667 }
1668
1669 /**
1670  * Escapes the given text so that it may be output using addWikiText()
1671  * without any linking, formatting, etc. making its way through. This
1672  * is achieved by substituting certain characters with HTML entities.
1673  * As required by the callers, <nowiki> is not used.
1674  *
1675  * @param $text String: text to be escaped
1676  * @return String
1677  */
1678 function wfEscapeWikiText( $text ) {
1679         $text = strtr( "\n$text", array(
1680                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1681                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1682                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1683                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1684                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1685                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1686         ) );
1687         return substr( $text, 1 );
1688 }
1689
1690 /**
1691  * Get the current unix timetstamp with microseconds.  Useful for profiling
1692  * @return Float
1693  */
1694 function wfTime() {
1695         return microtime( true );
1696 }
1697
1698 /**
1699  * Sets dest to source and returns the original value of dest
1700  * If source is NULL, it just returns the value, it doesn't set the variable
1701  * If force is true, it will set the value even if source is NULL
1702  *
1703  * @param $dest Mixed
1704  * @param $source Mixed
1705  * @param $force Bool
1706  * @return Mixed
1707  */
1708 function wfSetVar( &$dest, $source, $force = false ) {
1709         $temp = $dest;
1710         if ( !is_null( $source ) || $force ) {
1711                 $dest = $source;
1712         }
1713         return $temp;
1714 }
1715
1716 /**
1717  * As for wfSetVar except setting a bit
1718  *
1719  * @param $dest Int
1720  * @param $bit Int
1721  * @param $state Bool
1722  */
1723 function wfSetBit( &$dest, $bit, $state = true ) {
1724         $temp = (bool)( $dest & $bit );
1725         if ( !is_null( $state ) ) {
1726                 if ( $state ) {
1727                         $dest |= $bit;
1728                 } else {
1729                         $dest &= ~$bit;
1730                 }
1731         }
1732         return $temp;
1733 }
1734
1735 /**
1736  * Windows-compatible version of escapeshellarg()
1737  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1738  * function puts single quotes in regardless of OS.
1739  *
1740  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1741  * earlier distro releases of PHP)
1742  *
1743  * @param varargs
1744  * @return String
1745  */
1746 function wfEscapeShellArg( ) {
1747         wfInitShellLocale();
1748
1749         $args = func_get_args();
1750         $first = true;
1751         $retVal = '';
1752         foreach ( $args as $arg ) {
1753                 if ( !$first ) {
1754                         $retVal .= ' ';
1755                 } else {
1756                         $first = false;
1757                 }
1758
1759                 if ( wfIsWindows() ) {
1760                         // Escaping for an MSVC-style command line parser and CMD.EXE
1761                         // Refs:
1762                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1763                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1764                         //  * Bug #13518
1765                         //  * CR r63214
1766                         // Double the backslashes before any double quotes. Escape the double quotes.
1767                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1768                         $arg = '';
1769                         $iteration = 0;
1770                         foreach ( $tokens as $token ) {
1771                                 if ( $iteration % 2 == 1 ) {
1772                                         // Delimiter, a double quote preceded by zero or more slashes
1773                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1774                                 } elseif ( $iteration % 4 == 2 ) {
1775                                         // ^ in $token will be outside quotes, need to be escaped
1776                                         $arg .= str_replace( '^', '^^', $token );
1777                                 } else { // $iteration % 4 == 0
1778                                         // ^ in $token will appear inside double quotes, so leave as is
1779                                         $arg .= $token;
1780                                 }
1781                                 $iteration++;
1782                         }
1783                         // Double the backslashes before the end of the string, because
1784                         // we will soon add a quote
1785                         $m = array();
1786                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1787                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1788                         }
1789
1790                         // Add surrounding quotes
1791                         $retVal .= '"' . $arg . '"';
1792                 } else {
1793                         $retVal .= escapeshellarg( $arg );
1794                 }
1795         }
1796         return $retVal;
1797 }
1798
1799 /**
1800  * wfMerge attempts to merge differences between three texts.
1801  * Returns true for a clean merge and false for failure or a conflict.
1802  *
1803  * @param $old String
1804  * @param $mine String
1805  * @param $yours String
1806  * @param $result String
1807  * @return Bool
1808  */
1809 function wfMerge( $old, $mine, $yours, &$result ) {
1810         global $wgDiff3;
1811
1812         # This check may also protect against code injection in
1813         # case of broken installations.
1814         wfSuppressWarnings();
1815         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1816         wfRestoreWarnings();
1817
1818         if( !$haveDiff3 ) {
1819                 wfDebug( "diff3 not found\n" );
1820                 return false;
1821         }
1822
1823         # Make temporary files
1824         $td = wfTempDir();
1825         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1826         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1827         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1828
1829         fwrite( $oldtextFile, $old );
1830         fclose( $oldtextFile );
1831         fwrite( $mytextFile, $mine );
1832         fclose( $mytextFile );
1833         fwrite( $yourtextFile, $yours );
1834         fclose( $yourtextFile );
1835
1836         # Check for a conflict
1837         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1838                 wfEscapeShellArg( $mytextName ) . ' ' .
1839                 wfEscapeShellArg( $oldtextName ) . ' ' .
1840                 wfEscapeShellArg( $yourtextName );
1841         $handle = popen( $cmd, 'r' );
1842
1843         if( fgets( $handle, 1024 ) ) {
1844                 $conflict = true;
1845         } else {
1846                 $conflict = false;
1847         }
1848         pclose( $handle );
1849
1850         # Merge differences
1851         $cmd = $wgDiff3 . ' -a -e --merge ' .
1852                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1853         $handle = popen( $cmd, 'r' );
1854         $result = '';
1855         do {
1856                 $data = fread( $handle, 8192 );
1857                 if ( strlen( $data ) == 0 ) {
1858                         break;
1859                 }
1860                 $result .= $data;
1861         } while ( true );
1862         pclose( $handle );
1863         unlink( $mytextName );
1864         unlink( $oldtextName );
1865         unlink( $yourtextName );
1866
1867         if ( $result === '' && $old !== '' && !$conflict ) {
1868                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1869                 $conflict = true;
1870         }
1871         return !$conflict;
1872 }
1873
1874 /**
1875  * Returns unified plain-text diff of two texts.
1876  * Useful for machine processing of diffs.
1877  *
1878  * @param $before String: the text before the changes.
1879  * @param $after String: the text after the changes.
1880  * @param $params String: command-line options for the diff command.
1881  * @return String: unified diff of $before and $after
1882  */
1883 function wfDiff( $before, $after, $params = '-u' ) {
1884         if ( $before == $after ) {
1885                 return '';
1886         }
1887
1888         global $wgDiff;
1889         wfSuppressWarnings();
1890         $haveDiff = $wgDiff && file_exists( $wgDiff );
1891         wfRestoreWarnings();
1892
1893         # This check may also protect against code injection in
1894         # case of broken installations.
1895         if( !$haveDiff ) {
1896                 wfDebug( "diff executable not found\n" );
1897                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1898                 $format = new UnifiedDiffFormatter();
1899                 return $format->format( $diffs );
1900         }
1901
1902         # Make temporary files
1903         $td = wfTempDir();
1904         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1905         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1906
1907         fwrite( $oldtextFile, $before );
1908         fclose( $oldtextFile );
1909         fwrite( $newtextFile, $after );
1910         fclose( $newtextFile );
1911
1912         // Get the diff of the two files
1913         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1914
1915         $h = popen( $cmd, 'r' );
1916
1917         $diff = '';
1918
1919         do {
1920                 $data = fread( $h, 8192 );
1921                 if ( strlen( $data ) == 0 ) {
1922                         break;
1923                 }
1924                 $diff .= $data;
1925         } while ( true );
1926
1927         // Clean up
1928         pclose( $h );
1929         unlink( $oldtextName );
1930         unlink( $newtextName );
1931
1932         // Kill the --- and +++ lines. They're not useful.
1933         $diff_lines = explode( "\n", $diff );
1934         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1935                 unset( $diff_lines[0] );
1936         }
1937         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1938                 unset( $diff_lines[1] );
1939         }
1940
1941         $diff = implode( "\n", $diff_lines );
1942
1943         return $diff;
1944 }
1945
1946 /**
1947  * A wrapper around the PHP function var_export().
1948  * Either print it or add it to the regular output ($wgOut).
1949  *
1950  * @param $var A PHP variable to dump.
1951  */
1952 function wfVarDump( $var ) {
1953         global $wgOut;
1954         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1955         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1956                 print $s;
1957         } else {
1958                 $wgOut->addHTML( $s );
1959         }
1960 }
1961
1962 /**
1963  * Provide a simple HTTP error.
1964  *
1965  * @param $code Int|String
1966  * @param $label String
1967  * @param $desc String
1968  */
1969 function wfHttpError( $code, $label, $desc ) {
1970         global $wgOut;
1971         $wgOut->disable();
1972         header( "HTTP/1.0 $code $label" );
1973         header( "Status: $code $label" );
1974         $wgOut->sendCacheControl();
1975
1976         header( 'Content-type: text/html; charset=utf-8' );
1977         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1978                 '<html><head><title>' .
1979                 htmlspecialchars( $label ) .
1980                 '</title></head><body><h1>' .
1981                 htmlspecialchars( $label ) .
1982                 '</h1><p>' .
1983                 nl2br( htmlspecialchars( $desc ) ) .
1984                 "</p></body></html>\n";
1985 }
1986
1987 /**
1988  * Clear away any user-level output buffers, discarding contents.
1989  *
1990  * Suitable for 'starting afresh', for instance when streaming
1991  * relatively large amounts of data without buffering, or wanting to
1992  * output image files without ob_gzhandler's compression.
1993  *
1994  * The optional $resetGzipEncoding parameter controls suppression of
1995  * the Content-Encoding header sent by ob_gzhandler; by default it
1996  * is left. See comments for wfClearOutputBuffers() for why it would
1997  * be used.
1998  *
1999  * Note that some PHP configuration options may add output buffer
2000  * layers which cannot be removed; these are left in place.
2001  *
2002  * @param $resetGzipEncoding Bool
2003  */
2004 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2005         if( $resetGzipEncoding ) {
2006                 // Suppress Content-Encoding and Content-Length
2007                 // headers from 1.10+s wfOutputHandler
2008                 global $wgDisableOutputCompression;
2009                 $wgDisableOutputCompression = true;
2010         }
2011         while( $status = ob_get_status() ) {
2012                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2013                         // Probably from zlib.output_compression or other
2014                         // PHP-internal setting which can't be removed.
2015                         //
2016                         // Give up, and hope the result doesn't break
2017                         // output behavior.
2018                         break;
2019                 }
2020                 if( !ob_end_clean() ) {
2021                         // Could not remove output buffer handler; abort now
2022                         // to avoid getting in some kind of infinite loop.
2023                         break;
2024                 }
2025                 if( $resetGzipEncoding ) {
2026                         if( $status['name'] == 'ob_gzhandler' ) {
2027                                 // Reset the 'Content-Encoding' field set by this handler
2028                                 // so we can start fresh.
2029                                 if ( function_exists( 'header_remove' ) ) {
2030                                         // Available since PHP 5.3.0
2031                                         header_remove( 'Content-Encoding' );
2032                                 } else {
2033                                         // We need to provide a valid content-coding. See bug 28069
2034                                         header( 'Content-Encoding: identity' );
2035                                 }
2036                                 break;
2037                         }
2038                 }
2039         }
2040 }
2041
2042 /**
2043  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2044  *
2045  * Clear away output buffers, but keep the Content-Encoding header
2046  * produced by ob_gzhandler, if any.
2047  *
2048  * This should be used for HTTP 304 responses, where you need to
2049  * preserve the Content-Encoding header of the real result, but
2050  * also need to suppress the output of ob_gzhandler to keep to spec
2051  * and avoid breaking Firefox in rare cases where the headers and
2052  * body are broken over two packets.
2053  */
2054 function wfClearOutputBuffers() {
2055         wfResetOutputBuffers( false );
2056 }
2057
2058 /**
2059  * Converts an Accept-* header into an array mapping string values to quality
2060  * factors
2061  *
2062  * @param $accept String
2063  * @param $def String default
2064  * @return Array
2065  */
2066 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2067         # No arg means accept anything (per HTTP spec)
2068         if( !$accept ) {
2069                 return array( $def => 1.0 );
2070         }
2071
2072         $prefs = array();
2073
2074         $parts = explode( ',', $accept );
2075
2076         foreach( $parts as $part ) {
2077                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2078                 $values = explode( ';', trim( $part ) );
2079                 $match = array();
2080                 if ( count( $values ) == 1 ) {
2081                         $prefs[$values[0]] = 1.0;
2082                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2083                         $prefs[$values[0]] = floatval( $match[1] );
2084                 }
2085         }
2086
2087         return $prefs;
2088 }
2089
2090 /**
2091  * Checks if a given MIME type matches any of the keys in the given
2092  * array. Basic wildcards are accepted in the array keys.
2093  *
2094  * Returns the matching MIME type (or wildcard) if a match, otherwise
2095  * NULL if no match.
2096  *
2097  * @param $type String
2098  * @param $avail Array
2099  * @return string
2100  * @private
2101  */
2102 function mimeTypeMatch( $type, $avail ) {
2103         if( array_key_exists( $type, $avail ) ) {
2104                 return $type;
2105         } else {
2106                 $parts = explode( '/', $type );
2107                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2108                         return $parts[0] . '/*';
2109                 } elseif( array_key_exists( '*/*', $avail ) ) {
2110                         return '*/*';
2111                 } else {
2112                         return null;
2113                 }
2114         }
2115 }
2116
2117 /**
2118  * Returns the 'best' match between a client's requested internet media types
2119  * and the server's list of available types. Each list should be an associative
2120  * array of type to preference (preference is a float between 0.0 and 1.0).
2121  * Wildcards in the types are acceptable.
2122  *
2123  * @param $cprefs Array: client's acceptable type list
2124  * @param $sprefs Array: server's offered types
2125  * @return string
2126  *
2127  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2128  * XXX: generalize to negotiate other stuff
2129  */
2130 function wfNegotiateType( $cprefs, $sprefs ) {
2131         $combine = array();
2132
2133         foreach( array_keys($sprefs) as $type ) {
2134                 $parts = explode( '/', $type );
2135                 if( $parts[1] != '*' ) {
2136                         $ckey = mimeTypeMatch( $type, $cprefs );
2137                         if( $ckey ) {
2138                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2139                         }
2140                 }
2141         }
2142
2143         foreach( array_keys( $cprefs ) as $type ) {
2144                 $parts = explode( '/', $type );
2145                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2146                         $skey = mimeTypeMatch( $type, $sprefs );
2147                         if( $skey ) {
2148                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2149                         }
2150                 }
2151         }
2152
2153         $bestq = 0;
2154         $besttype = null;
2155
2156         foreach( array_keys( $combine ) as $type ) {
2157                 if( $combine[$type] > $bestq ) {
2158                         $besttype = $type;
2159                         $bestq = $combine[$type];
2160                 }
2161         }
2162
2163         return $besttype;
2164 }
2165
2166 /**
2167  * Reference-counted warning suppression
2168  *
2169  * @param $end Bool
2170  */
2171 function wfSuppressWarnings( $end = false ) {
2172         static $suppressCount = 0;
2173         static $originalLevel = false;
2174
2175         if ( $end ) {
2176                 if ( $suppressCount ) {
2177                         --$suppressCount;
2178                         if ( !$suppressCount ) {
2179                                 error_reporting( $originalLevel );
2180                         }
2181                 }
2182         } else {
2183                 if ( !$suppressCount ) {
2184                         // E_DEPRECATED is undefined in PHP 5.2
2185                         if( !defined( 'E_DEPRECATED' ) ){
2186                                 define( 'E_DEPRECATED', 8192 );
2187                         }
2188                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2189                 }
2190                 ++$suppressCount;
2191         }
2192 }
2193
2194 /**
2195  * Restore error level to previous value
2196  */
2197 function wfRestoreWarnings() {
2198         wfSuppressWarnings( true );
2199 }
2200
2201 # Autodetect, convert and provide timestamps of various types
2202
2203 /**
2204  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2205  */
2206 define( 'TS_UNIX', 0 );
2207
2208 /**
2209  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2210  */
2211 define( 'TS_MW', 1 );
2212
2213 /**
2214  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2215  */
2216 define( 'TS_DB', 2 );
2217
2218 /**
2219  * RFC 2822 format, for E-mail and HTTP headers
2220  */
2221 define( 'TS_RFC2822', 3 );
2222
2223 /**
2224  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2225  *
2226  * This is used by Special:Export
2227  */
2228 define( 'TS_ISO_8601', 4 );
2229
2230 /**
2231  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2232  *
2233  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2234  *       DateTime tag and page 36 for the DateTimeOriginal and
2235  *       DateTimeDigitized tags.
2236  */
2237 define( 'TS_EXIF', 5 );
2238
2239 /**
2240  * Oracle format time.
2241  */
2242 define( 'TS_ORACLE', 6 );
2243
2244 /**
2245  * Postgres format time.
2246  */
2247 define( 'TS_POSTGRES', 7 );
2248
2249 /**
2250  * DB2 format time
2251  */
2252 define( 'TS_DB2', 8 );
2253
2254 /**
2255  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2256  */
2257 define( 'TS_ISO_8601_BASIC', 9 );
2258
2259 /**
2260  * Get a timestamp string in one of various formats
2261  *
2262  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2263  *                    function will autodetect which format is supplied and act
2264  *                    accordingly.
2265  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2266  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2267  */
2268 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2269         $uts = 0;
2270         $da = array();
2271         $strtime = '';
2272
2273         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2274                 $uts = time();
2275                 $strtime = "@$uts";
2276         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2277                 # TS_DB
2278         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2279                 # TS_EXIF
2280         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2281                 # TS_MW
2282         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2283                 # TS_UNIX
2284                 $uts = $ts;
2285                 $strtime = "@$ts"; // Undocumented?
2286         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2287                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2288                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2289                                 str_replace( '+00:00', 'UTC', $ts ) );
2290         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2291                 # TS_ISO_8601
2292         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2293                 #TS_ISO_8601_BASIC
2294         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2295                 # TS_POSTGRES
2296         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2297                 # TS_POSTGRES
2298         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2299                 # TS_DB2
2300         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2301                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2302                                                         '[ \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
2303                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2304                 # The regex is a superset of rfc2822 for readability
2305                 $strtime = strtok( $ts, ';' );
2306         } 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 ) ) {
2307                 # TS_RFC850
2308                 $strtime = $ts;
2309         } 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 ) ) {
2310                 # asctime
2311                 $strtime = $ts;
2312         } else {
2313                 # Bogus value...
2314                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2315
2316                 return false;
2317         }
2318
2319         static $formats = array(
2320                 TS_UNIX => 'U',
2321                 TS_MW => 'YmdHis',
2322                 TS_DB => 'Y-m-d H:i:s',
2323                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2324                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2325                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2326                 TS_RFC2822 => 'D, d M Y H:i:s',
2327                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2328                 TS_POSTGRES => 'Y-m-d H:i:s',
2329                 TS_DB2 => 'Y-m-d H:i:s',
2330         );
2331
2332         if ( !isset( $formats[$outputtype] ) ) {
2333                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2334         }
2335
2336         if ( function_exists( "date_create" ) ) {
2337                 if ( count( $da ) ) {
2338                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2339                                 (int)$da[1], (int)$da[2], (int)$da[3],
2340                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2341
2342                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2343                 } elseif ( $strtime ) {
2344                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2345                 } else {
2346                         return false;
2347                 }
2348
2349                 if ( !$d ) {
2350                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2351                         return false;
2352                 }
2353
2354                 $output = $d->format( $formats[$outputtype] );
2355         } else {
2356                 if ( count( $da ) ) {
2357                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2358                         // We may want to handle that explicitly at some point
2359                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2360                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2361                 } elseif ( $strtime ) {
2362                         $uts = strtotime( $strtime );
2363                 }
2364
2365                 if ( $uts === false ) {
2366                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2367                         return false;
2368                 }
2369
2370                 if ( TS_UNIX == $outputtype ) {
2371                         return $uts;
2372                 }
2373                 $output = gmdate( $formats[$outputtype], $uts );
2374         }
2375
2376         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2377                 $output .= ' GMT';
2378         }
2379
2380         return $output;
2381 }
2382
2383 /**
2384  * Return a formatted timestamp, or null if input is null.
2385  * For dealing with nullable timestamp columns in the database.
2386  *
2387  * @param $outputtype Integer
2388  * @param $ts String
2389  * @return String
2390  */
2391 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2392         if( is_null( $ts ) ) {
2393                 return null;
2394         } else {
2395                 return wfTimestamp( $outputtype, $ts );
2396         }
2397 }
2398
2399 /**
2400  * Convenience function; returns MediaWiki timestamp for the present time.
2401  *
2402  * @return string
2403  */
2404 function wfTimestampNow() {
2405         # return NOW
2406         return wfTimestamp( TS_MW, time() );
2407 }
2408
2409 /**
2410  * Check if the operating system is Windows
2411  *
2412  * @return Bool: true if it's Windows, False otherwise.
2413  */
2414 function wfIsWindows() {
2415         static $isWindows = null;
2416         if ( $isWindows === null ) {
2417                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2418         }
2419         return $isWindows;
2420 }
2421
2422 /**
2423  * Check if we are running under HipHop
2424  *
2425  * @return Bool
2426  */
2427 function wfIsHipHop() {
2428         return function_exists( 'hphp_thread_set_warmup_enabled' );
2429 }
2430
2431 /**
2432  * Swap two variables
2433  *
2434  * @param $x Mixed
2435  * @param $y Mixed
2436  */
2437 function swap( &$x, &$y ) {
2438         $z = $x;
2439         $x = $y;
2440         $y = $z;
2441 }
2442
2443 /**
2444  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2445  * TEMP environment variables are then checked in sequence, and if none are set
2446  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2447  * or C:\Windows\Temp for Windows and hope for the best.
2448  * It is common to call it with tempnam().
2449  *
2450  * NOTE: When possible, use instead the tmpfile() function to create
2451  * temporary files to avoid race conditions on file creation, etc.
2452  *
2453  * @return String
2454  */
2455 function wfTempDir() {
2456         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2457                 $tmp = getenv( $var );
2458                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2459                         return $tmp;
2460                 }
2461         }
2462         if( function_exists( 'sys_get_temp_dir' ) ) {
2463                 return sys_get_temp_dir();
2464         }
2465         # Usual defaults
2466         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2467 }
2468
2469 /**
2470  * Make directory, and make all parent directories if they don't exist
2471  *
2472  * @param $dir String: full path to directory to create
2473  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2474  * @param $caller String: optional caller param for debugging.
2475  * @return bool
2476  */
2477 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2478         global $wgDirectoryMode;
2479
2480         if ( !is_null( $caller ) ) {
2481                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2482         }
2483
2484         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2485                 return true;
2486         }
2487
2488         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2489
2490         if ( is_null( $mode ) ) {
2491                 $mode = $wgDirectoryMode;
2492         }
2493
2494         // Turn off the normal warning, we're doing our own below
2495         wfSuppressWarnings();
2496         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2497         wfRestoreWarnings();
2498
2499         if( !$ok ) {
2500                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2501                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2502         }
2503         return $ok;
2504 }
2505
2506 /**
2507  * Increment a statistics counter
2508  *
2509  * @param $key String
2510  * @param $count Int
2511  */
2512 function wfIncrStats( $key, $count = 1 ) {
2513         global $wgStatsMethod;
2514
2515         $count = intval( $count );
2516
2517         if( $wgStatsMethod == 'udp' ) {
2518                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2519                 static $socket;
2520
2521                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2522
2523                 if ( !$socket ) {
2524                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2525                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2526                         socket_sendto(
2527                                 $socket,
2528                                 $statline,
2529                                 strlen( $statline ),
2530                                 0,
2531                                 $wgUDPProfilerHost,
2532                                 $wgUDPProfilerPort
2533                         );
2534                 }
2535                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2536                 wfSuppressWarnings();
2537                 socket_sendto(
2538                         $socket,
2539                         $statline,
2540                         strlen( $statline ),
2541                         0,
2542                         $wgUDPProfilerHost,
2543                         $wgUDPProfilerPort
2544                 );
2545                 wfRestoreWarnings();
2546         } elseif( $wgStatsMethod == 'cache' ) {
2547                 global $wgMemc;
2548                 $key = wfMemcKey( 'stats', $key );
2549                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2550                         $wgMemc->add( $key, $count );
2551                 }
2552         } else {
2553                 // Disabled
2554         }
2555 }
2556
2557 /**
2558  * @param $nr Mixed: the number to format
2559  * @param $acc Integer: the number of digits after the decimal point, default 2
2560  * @param $round Boolean: whether or not to round the value, default true
2561  * @return float
2562  */
2563 function wfPercent( $nr, $acc = 2, $round = true ) {
2564         $ret = sprintf( "%.${acc}f", $nr );
2565         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2566 }
2567
2568 /**
2569  * Find out whether or not a mixed variable exists in a string
2570  *
2571  * @param $needle String
2572  * @param $str String
2573  * @param $insensitive Boolean
2574  * @return Boolean
2575  */
2576 function in_string( $needle, $str, $insensitive = false ) {
2577         $func = 'strpos';
2578         if( $insensitive ) $func = 'stripos';
2579
2580         return $func( $str, $needle ) !== false;
2581 }
2582
2583 /**
2584  * Make a list item, used by various special pages
2585  *
2586  * @param $page String Page link
2587  * @param $details String Text between brackets
2588  * @param $oppositedm Boolean   Add the direction mark opposite to your
2589  *                                                              language, to display text properly
2590  * @return String
2591  */
2592 function wfSpecialList( $page, $details, $oppositedm = true ) {
2593         global $wgLang;
2594         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2595                 $wgLang->getDirMark();
2596         $details = $details ? $dirmark . " ($details)" : '';
2597         return $page . $details;
2598 }
2599
2600 /**
2601  * Safety wrapper around ini_get() for boolean settings.
2602  * The values returned from ini_get() are pre-normalized for settings
2603  * set via php.ini or php_flag/php_admin_flag... but *not*
2604  * for those set via php_value/php_admin_value.
2605  *
2606  * It's fairly common for people to use php_value instead of php_flag,
2607  * which can leave you with an 'off' setting giving a false positive
2608  * for code that just takes the ini_get() return value as a boolean.
2609  *
2610  * To make things extra interesting, setting via php_value accepts
2611  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2612  * Unrecognized values go false... again opposite PHP's own coercion
2613  * from string to bool.
2614  *
2615  * Luckily, 'properly' set settings will always come back as '0' or '1',
2616  * so we only have to worry about them and the 'improper' settings.
2617  *
2618  * I frickin' hate PHP... :P
2619  *
2620  * @param $setting String
2621  * @return Bool
2622  */
2623 function wfIniGetBool( $setting ) {
2624         $val = ini_get( $setting );
2625         // 'on' and 'true' can't have whitespace around them, but '1' can.
2626         return strtolower( $val ) == 'on'
2627                 || strtolower( $val ) == 'true'
2628                 || strtolower( $val ) == 'yes'
2629                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2630 }
2631
2632 /**
2633  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2634  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2635  *
2636  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2637  *                          should be omitted
2638  * @param $fileName String Name of the library, if not $extension.suffix
2639  * @return Bool - Whether or not the extension is loaded
2640  */
2641 function wfDl( $extension, $fileName = null ) {
2642         if( extension_loaded( $extension ) ) {
2643                 return true;
2644         }
2645
2646         $canDl = false;
2647         $sapi = php_sapi_name();
2648         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2649                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2650         {
2651                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2652                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2653         }
2654
2655         if( $canDl ) {
2656                 $fileName = $fileName ? $fileName : $extension;
2657                 if( wfIsWindows() ) {
2658                         $fileName = 'php_' . $fileName;
2659                 }
2660                 wfSuppressWarnings();
2661                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2662                 wfRestoreWarnings();
2663         }
2664         return extension_loaded( $extension );
2665 }
2666
2667 /**
2668  * Execute a shell command, with time and memory limits mirrored from the PHP
2669  * configuration if supported.
2670  * @param $cmd String Command line, properly escaped for shell.
2671  * @param &$retval optional, will receive the program's exit code.
2672  *                 (non-zero is usually failure)
2673  * @param $environ Array optional environment variables which should be
2674  *                 added to the executed command environment.
2675  * @return collected stdout as a string (trailing newlines stripped)
2676  */
2677 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2678         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2679
2680         static $disabled;
2681         if ( is_null( $disabled ) ) {
2682                 $disabled = false;
2683                 if( wfIniGetBool( 'safe_mode' ) ) {
2684                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2685                         $disabled = 'safemode';
2686                 } else {
2687                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2688                         $functions = array_map( 'trim', $functions );
2689                         $functions = array_map( 'strtolower', $functions );
2690                         if ( in_array( 'passthru', $functions ) ) {
2691                                 wfDebug( "passthru is in disabled_functions\n" );
2692                                 $disabled = 'passthru';
2693                         }
2694                 }
2695         }
2696         if ( $disabled ) {
2697                 $retval = 1;
2698                 return $disabled == 'safemode' ?
2699                         'Unable to run external programs in safe mode.' :
2700                         'Unable to run external programs, passthru() is disabled.';
2701         }
2702
2703         wfInitShellLocale();
2704
2705         $envcmd = '';
2706         foreach( $environ as $k => $v ) {
2707                 if ( wfIsWindows() ) {
2708                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2709                          * appear in the environment variable, so we must use carat escaping as documented in
2710                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2711                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2712                          * are listed there but doesn't appear to need it.
2713                          */
2714                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2715                 } else {
2716                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2717                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2718                          */
2719                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2720                 }
2721         }
2722         $cmd = $envcmd . $cmd;
2723
2724         if ( wfIsWindows() ) {
2725                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2726                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2727                 {
2728                         # Hack to work around PHP's flawed invocation of cmd.exe
2729                         # http://news.php.net/php.internals/21796
2730                         # Windows 9x doesn't accept any kind of quotes
2731                         $cmd = '"' . $cmd . '"';
2732                 }
2733         } elseif ( php_uname( 's' ) == 'Linux' ) {
2734                 $time = intval( $wgMaxShellTime );
2735                 $mem = intval( $wgMaxShellMemory );
2736                 $filesize = intval( $wgMaxShellFileSize );
2737
2738                 if ( $time > 0 && $mem > 0 ) {
2739                         $script = "$IP/bin/ulimit4.sh";
2740                         if ( is_executable( $script ) ) {
2741                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2742                         }
2743                 }
2744         }
2745         wfDebug( "wfShellExec: $cmd\n" );
2746
2747         $retval = 1; // error by default?
2748         ob_start();
2749         passthru( $cmd, $retval );
2750         $output = ob_get_contents();
2751         ob_end_clean();
2752
2753         if ( $retval == 127 ) {
2754                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2755         }
2756         return $output;
2757 }
2758
2759 /**
2760  * Workaround for http://bugs.php.net/bug.php?id=45132
2761  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2762  */
2763 function wfInitShellLocale() {
2764         static $done = false;
2765         if ( $done ) {
2766                 return;
2767         }
2768         $done = true;
2769         global $wgShellLocale;
2770         if ( !wfIniGetBool( 'safe_mode' ) ) {
2771                 putenv( "LC_CTYPE=$wgShellLocale" );
2772                 setlocale( LC_CTYPE, $wgShellLocale );
2773         }
2774 }
2775
2776 /**
2777  * This function works like "use VERSION" in Perl, the program will die with a
2778  * backtrace if the current version of PHP is less than the version provided
2779  *
2780  * This is useful for extensions which due to their nature are not kept in sync
2781  * with releases, and might depend on other versions of PHP than the main code
2782  *
2783  * Note: PHP might die due to parsing errors in some cases before it ever
2784  *       manages to call this function, such is life
2785  *
2786  * @see perldoc -f use
2787  *
2788  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2789  *                 a float
2790  */
2791 function wfUsePHP( $req_ver ) {
2792         $php_ver = PHP_VERSION;
2793
2794         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2795                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2796         }
2797 }
2798
2799 /**
2800  * This function works like "use VERSION" in Perl except it checks the version
2801  * of MediaWiki, the program will die with a backtrace if the current version
2802  * of MediaWiki is less than the version provided.
2803  *
2804  * This is useful for extensions which due to their nature are not kept in sync
2805  * with releases
2806  *
2807  * @see perldoc -f use
2808  *
2809  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2810  *                 a float
2811  */
2812 function wfUseMW( $req_ver ) {
2813         global $wgVersion;
2814
2815         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2816                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2817         }
2818 }
2819
2820 /**
2821  * Return the final portion of a pathname.
2822  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2823  * http://bugs.php.net/bug.php?id=33898
2824  *
2825  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2826  * We'll consider it so always, as we don't want \s in our Unix paths either.
2827  *
2828  * @param $path String
2829  * @param $suffix String: to remove if present
2830  * @return String
2831  */
2832 function wfBaseName( $path, $suffix = '' ) {
2833         $encSuffix = ( $suffix == '' )
2834                 ? ''
2835                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2836         $matches = array();
2837         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2838                 return $matches[1];
2839         } else {
2840                 return '';
2841         }
2842 }
2843
2844 /**
2845  * Generate a relative path name to the given file.
2846  * May explode on non-matching case-insensitive paths,
2847  * funky symlinks, etc.
2848  *
2849  * @param $path String: absolute destination path including target filename
2850  * @param $from String: Absolute source path, directory only
2851  * @return String
2852  */
2853 function wfRelativePath( $path, $from ) {
2854         // Normalize mixed input on Windows...
2855         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2856         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2857
2858         // Trim trailing slashes -- fix for drive root
2859         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2860         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2861
2862         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2863         $against = explode( DIRECTORY_SEPARATOR, $from );
2864
2865         if( $pieces[0] !== $against[0] ) {
2866                 // Non-matching Windows drive letters?
2867                 // Return a full path.
2868                 return $path;
2869         }
2870
2871         // Trim off common prefix
2872         while( count( $pieces ) && count( $against )
2873                 && $pieces[0] == $against[0] ) {
2874                 array_shift( $pieces );
2875                 array_shift( $against );
2876         }
2877
2878         // relative dots to bump us to the parent
2879         while( count( $against ) ) {
2880                 array_unshift( $pieces, '..' );
2881                 array_shift( $against );
2882         }
2883
2884         array_push( $pieces, wfBaseName( $path ) );
2885
2886         return implode( DIRECTORY_SEPARATOR, $pieces );
2887 }
2888
2889 /**
2890  * Do any deferred updates and clear the list
2891  *
2892  * @param $commit String: set to 'commit' to commit after every update to
2893  *                prevent lock contention
2894  */
2895 function wfDoUpdates( $commit = '' ) {
2896         global $wgDeferredUpdateList;
2897
2898         wfProfileIn( __METHOD__ );
2899
2900         // No need to get master connections in case of empty updates array
2901         if ( !count( $wgDeferredUpdateList ) ) {
2902                 wfProfileOut( __METHOD__ );
2903                 return;
2904         }
2905
2906         $doCommit = $commit == 'commit';
2907         if ( $doCommit ) {
2908                 $dbw = wfGetDB( DB_MASTER );
2909         }
2910
2911         foreach ( $wgDeferredUpdateList as $update ) {
2912                 $update->doUpdate();
2913
2914                 if ( $doCommit && $dbw->trxLevel() ) {
2915                         $dbw->commit();
2916                 }
2917         }
2918
2919         $wgDeferredUpdateList = array();
2920         wfProfileOut( __METHOD__ );
2921 }
2922
2923 /**
2924  * Convert an arbitrarily-long digit string from one numeric base
2925  * to another, optionally zero-padding to a minimum column width.
2926  *
2927  * Supports base 2 through 36; digit values 10-36 are represented
2928  * as lowercase letters a-z. Input is case-insensitive.
2929  *
2930  * @param $input String: of digits
2931  * @param $sourceBase Integer: 2-36
2932  * @param $destBase Integer: 2-36
2933  * @param $pad Integer: 1 or greater
2934  * @param $lowercase Boolean
2935  * @return String or false on invalid input
2936  */
2937 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2938         $input = strval( $input );
2939         if( $sourceBase < 2 ||
2940                 $sourceBase > 36 ||
2941                 $destBase < 2 ||
2942                 $destBase > 36 ||
2943                 $pad < 1 ||
2944                 $sourceBase != intval( $sourceBase ) ||
2945                 $destBase != intval( $destBase ) ||
2946                 $pad != intval( $pad ) ||
2947                 !is_string( $input ) ||
2948                 $input == '' ) {
2949                 return false;
2950         }
2951         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2952         $inDigits = array();
2953         $outChars = '';
2954
2955         // Decode and validate input string
2956         $input = strtolower( $input );
2957         for( $i = 0; $i < strlen( $input ); $i++ ) {
2958                 $n = strpos( $digitChars, $input[$i] );
2959                 if( $n === false || $n > $sourceBase ) {
2960                         return false;
2961                 }
2962                 $inDigits[] = $n;
2963         }
2964
2965         // Iterate over the input, modulo-ing out an output digit
2966         // at a time until input is gone.
2967         while( count( $inDigits ) ) {
2968                 $work = 0;
2969                 $workDigits = array();
2970
2971                 // Long division...
2972                 foreach( $inDigits as $digit ) {
2973                         $work *= $sourceBase;
2974                         $work += $digit;
2975
2976                         if( $work < $destBase ) {
2977                                 // Gonna need to pull another digit.
2978                                 if( count( $workDigits ) ) {
2979                                         // Avoid zero-padding; this lets us find
2980                                         // the end of the input very easily when
2981                                         // length drops to zero.
2982                                         $workDigits[] = 0;
2983                                 }
2984                         } else {
2985                                 // Finally! Actual division!
2986                                 $workDigits[] = intval( $work / $destBase );
2987
2988                                 // Isn't it annoying that most programming languages
2989                                 // don't have a single divide-and-remainder operator,
2990                                 // even though the CPU implements it that way?
2991                                 $work = $work % $destBase;
2992                         }
2993                 }
2994
2995                 // All that division leaves us with a remainder,
2996                 // which is conveniently our next output digit.
2997                 $outChars .= $digitChars[$work];
2998
2999                 // And we continue!
3000                 $inDigits = $workDigits;
3001         }
3002
3003         while( strlen( $outChars ) < $pad ) {
3004                 $outChars .= '0';
3005         }
3006
3007         return strrev( $outChars );
3008 }
3009
3010 /**
3011  * Create an object with a given name and an array of construct parameters
3012  *
3013  * @param $name String
3014  * @param $p Array: parameters
3015  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3016  */
3017 function wfCreateObject( $name, $p ) {
3018         wfDeprecated( __FUNCTION__ );
3019         return MWFunction::newObj( $name, $p );
3020 }
3021
3022 function wfHttpOnlySafe() {
3023         global $wgHttpOnlyBlacklist;
3024
3025         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3026                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3027                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3028                                 return false;
3029                         }
3030                 }
3031         }
3032
3033         return true;
3034 }
3035
3036 /**
3037  * Initialise php session
3038  *
3039  * @param $sessionId Bool
3040  */
3041 function wfSetupSession( $sessionId = false ) {
3042         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3043                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3044         if( $wgSessionsInMemcached ) {
3045                 if ( !defined( 'MW_COMPILED' ) ) {
3046                         global $IP;
3047                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3048                 }
3049                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3050                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3051
3052                 // It's necessary to register a shutdown function to call session_write_close(),
3053                 // because by the time the request shutdown function for the session module is
3054                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3055                 // this way are called before object destruction.
3056                 register_shutdown_function( 'memsess_write_close' );
3057         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3058                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3059                 # hasn't already been set to the desired value (that causes errors)
3060                 ini_set( 'session.save_handler', $wgSessionHandler );
3061         }
3062         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3063         wfDebugLog( 'cookie',
3064                 'session_set_cookie_params: "' . implode( '", "',
3065                         array(
3066                                 0,
3067                                 $wgCookiePath,
3068                                 $wgCookieDomain,
3069                                 $wgCookieSecure,
3070                                 $httpOnlySafe ) ) . '"' );
3071         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3072         session_cache_limiter( 'private, must-revalidate' );
3073         if ( $sessionId ) {
3074                 session_id( $sessionId );
3075         }
3076         wfSuppressWarnings();
3077         session_start();
3078         wfRestoreWarnings();
3079 }
3080
3081 /**
3082  * Get an object from the precompiled serialized directory
3083  *
3084  * @param $name String
3085  * @return Mixed: the variable on success, false on failure
3086  */
3087 function wfGetPrecompiledData( $name ) {
3088         global $IP;
3089
3090         $file = "$IP/serialized/$name";
3091         if ( file_exists( $file ) ) {
3092                 $blob = file_get_contents( $file );
3093                 if ( $blob ) {
3094                         return unserialize( $blob );
3095                 }
3096         }
3097         return false;
3098 }
3099
3100 /**
3101  * Get a cache key
3102  *
3103  * @param varargs
3104  * @return String
3105  */
3106 function wfMemcKey( /*... */ ) {
3107         $args = func_get_args();
3108         $key = wfWikiID() . ':' . implode( ':', $args );
3109         $key = str_replace( ' ', '_', $key );
3110         return $key;
3111 }
3112
3113 /**
3114  * Get a cache key for a foreign DB
3115  *
3116  * @param $db String
3117  * @param $prefix String
3118  * @param varargs String
3119  * @return String
3120  */
3121 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3122         $args = array_slice( func_get_args(), 2 );
3123         if ( $prefix ) {
3124                 $key = "$db-$prefix:" . implode( ':', $args );
3125         } else {
3126                 $key = $db . ':' . implode( ':', $args );
3127         }
3128         return $key;
3129 }
3130
3131 /**
3132  * Get an ASCII string identifying this wiki
3133  * This is used as a prefix in memcached keys
3134  *
3135  * @return String
3136  */
3137 function wfWikiID() {
3138         global $wgDBprefix, $wgDBname;
3139         if ( $wgDBprefix ) {
3140                 return "$wgDBname-$wgDBprefix";
3141         } else {
3142                 return $wgDBname;
3143         }
3144 }
3145
3146 /**
3147  * Split a wiki ID into DB name and table prefix
3148  *
3149  * @param $wiki String
3150  * @param $bits String
3151  */
3152 function wfSplitWikiID( $wiki ) {
3153         $bits = explode( '-', $wiki, 2 );
3154         if ( count( $bits ) < 2 ) {
3155                 $bits[] = '';
3156         }
3157         return $bits;
3158 }
3159
3160 /**
3161  * Get a Database object.
3162  *
3163  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3164  *            master (for write queries), DB_SLAVE for potentially lagged read
3165  *            queries, or an integer >= 0 for a particular server.
3166  *
3167  * @param $groups Mixed: query groups. An array of group names that this query
3168  *                belongs to. May contain a single string if the query is only
3169  *                in one group.
3170  *
3171  * @param $wiki String: the wiki ID, or false for the current wiki
3172  *
3173  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3174  * will always return the same object, unless the underlying connection or load
3175  * balancer is manually destroyed.
3176  *
3177  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3178  * updater to ensure that a proper database is being updated.
3179  *
3180  * @return DatabaseBase
3181  */
3182 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3183         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3184 }
3185
3186 /**
3187  * Get a load balancer object.
3188  *
3189  * @param $wiki String: wiki ID, or false for the current wiki
3190  * @return LoadBalancer
3191  */
3192 function wfGetLB( $wiki = false ) {
3193         return wfGetLBFactory()->getMainLB( $wiki );
3194 }
3195
3196 /**
3197  * Get the load balancer factory object
3198  *
3199  * @return LBFactory
3200  */
3201 function &wfGetLBFactory() {
3202         return LBFactory::singleton();
3203 }
3204
3205 /**
3206  * Find a file.
3207  * Shortcut for RepoGroup::singleton()->findFile()
3208  *
3209  * @param $title String or Title object
3210  * @param $options Associative array of options:
3211  *     time:           requested time for an archived image, or false for the
3212  *                     current version. An image object will be returned which was
3213  *                     created at the specified time.
3214  *
3215  *     ignoreRedirect: If true, do not follow file redirects
3216  *
3217  *     private:        If true, return restricted (deleted) files if the current
3218  *                     user is allowed to view them. Otherwise, such files will not
3219  *                     be found.
3220  *
3221  *     bypassCache:    If true, do not use the process-local cache of File objects
3222  *
3223  * @return File, or false if the file does not exist
3224  */
3225 function wfFindFile( $title, $options = array() ) {
3226         return RepoGroup::singleton()->findFile( $title, $options );
3227 }
3228
3229 /**
3230  * Get an object referring to a locally registered file.
3231  * Returns a valid placeholder object if the file does not exist.
3232  *
3233  * @param $title Title or String
3234  * @return File, or null if passed an invalid Title
3235  */
3236 function wfLocalFile( $title ) {
3237         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3238 }
3239
3240 /**
3241  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3242  * @deprecated since 1.19
3243  */
3244 function wfStreamFile( $fname, $headers = array() ) {
3245         StreamFile::stream( $fname, $headers );
3246 }
3247
3248 /**
3249  * Should low-performance queries be disabled?
3250  *
3251  * @return Boolean
3252  * @codeCoverageIgnore
3253  */
3254 function wfQueriesMustScale() {
3255         global $wgMiserMode;
3256         return $wgMiserMode
3257                 || ( SiteStats::pages() > 100000
3258                 && SiteStats::edits() > 1000000
3259                 && SiteStats::users() > 10000 );
3260 }
3261
3262 /**
3263  * Get the path to a specified script file, respecting file
3264  * extensions; this is a wrapper around $wgScriptExtension etc.
3265  *
3266  * @param $script String: script filename, sans extension
3267  * @return String
3268  */
3269 function wfScript( $script = 'index' ) {
3270         global $wgScriptPath, $wgScriptExtension;
3271         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3272 }
3273
3274 /**
3275  * Get the script URL.
3276  *
3277  * @return script URL
3278  */
3279 function wfGetScriptUrl() {
3280         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3281                 #
3282                 # as it was called, minus the query string.
3283                 #
3284                 # Some sites use Apache rewrite rules to handle subdomains,
3285                 # and have PHP set up in a weird way that causes PHP_SELF
3286                 # to contain the rewritten URL instead of the one that the
3287                 # outside world sees.
3288                 #
3289                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3290                 # provides containing the "before" URL.
3291                 return $_SERVER['SCRIPT_NAME'];
3292         } else {
3293                 return $_SERVER['URL'];
3294         }
3295 }
3296
3297 /**
3298  * Convenience function converts boolean values into "true"
3299  * or "false" (string) values
3300  *
3301  * @param $value Boolean
3302  * @return String
3303  */
3304 function wfBoolToStr( $value ) {
3305         return $value ? 'true' : 'false';
3306 }
3307
3308 /**
3309  * Load an extension messages file
3310  *
3311  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3312  * @codeCoverageIgnore
3313  */
3314 function wfLoadExtensionMessages() {
3315         wfDeprecated( __FUNCTION__ );
3316 }
3317
3318 /**
3319  * Get a platform-independent path to the null file, e.g. /dev/null
3320  *
3321  * @return string
3322  */
3323 function wfGetNull() {
3324         return wfIsWindows()
3325                 ? 'NUL'
3326                 : '/dev/null';
3327 }
3328
3329 /**
3330  * Throws a warning that $function is deprecated
3331  *
3332  * @param $function String
3333  * @return null
3334  */
3335 function wfDeprecated( $function ) {
3336         static $functionsWarned = array();
3337         if ( !isset( $functionsWarned[$function] ) ) {
3338                 $functionsWarned[$function] = true;
3339                 wfWarn( "Use of $function is deprecated.", 2 );
3340         }
3341 }
3342
3343 /**
3344  * Send a warning either to the debug log or in a PHP error depending on
3345  * $wgDevelopmentWarnings
3346  *
3347  * @param $msg String: message to send
3348  * @param $callerOffset Integer: number of items to go back in the backtrace to
3349  *        find the correct caller (1 = function calling wfWarn, ...)
3350  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3351  *        is true
3352  */
3353 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3354         global $wgDevelopmentWarnings;
3355
3356         $callers = wfDebugBacktrace();
3357         if ( isset( $callers[$callerOffset + 1] ) ) {
3358                 $callerfunc = $callers[$callerOffset + 1];
3359                 $callerfile = $callers[$callerOffset];
3360                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3361                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3362                 } else {
3363                         $file = '(internal function)';
3364                 }
3365                 $func = '';
3366                 if ( isset( $callerfunc['class'] ) ) {
3367                         $func .= $callerfunc['class'] . '::';
3368                 }
3369                 if ( isset( $callerfunc['function'] ) ) {
3370                         $func .= $callerfunc['function'];
3371                 }
3372                 $msg .= " [Called from $func in $file]";
3373         }
3374
3375         if ( $wgDevelopmentWarnings ) {
3376                 trigger_error( $msg, $level );
3377         } else {
3378                 wfDebug( "$msg\n" );
3379         }
3380 }
3381
3382 /**
3383  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3384  * and waiting for it to go down, this waits for the slaves to catch up to the
3385  * master position. Use this when updating very large numbers of rows, as
3386  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3387  * a no-op if there are no slaves.
3388  *
3389  * @param $maxLag Integer (deprecated)
3390  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3391  * @return null
3392  */
3393 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3394         $lb = wfGetLB( $wiki );
3395         // bug 27975 - Don't try to wait for slaves if there are none
3396         // Prevents permission error when getting master position
3397         if ( $lb->getServerCount() > 1 ) {
3398                 $dbw = $lb->getConnection( DB_MASTER );
3399                 $pos = $dbw->getMasterPos();
3400                 $lb->waitForAll( $pos );
3401         }
3402 }
3403
3404 /**
3405  * Used to be used for outputting text in the installer/updater
3406  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3407  */
3408 function wfOut( $s ) {
3409         wfDeprecated( __METHOD__ );
3410         global $wgCommandLineMode;
3411         if ( $wgCommandLineMode ) {
3412                 echo $s;
3413         } else {
3414                 echo htmlspecialchars( $s );
3415         }
3416         flush();
3417 }
3418
3419 /**
3420  * Count down from $n to zero on the terminal, with a one-second pause
3421  * between showing each number. For use in command-line scripts.
3422  * @codeCoverageIgnore
3423  */
3424 function wfCountDown( $n ) {
3425         for ( $i = $n; $i >= 0; $i-- ) {
3426                 if ( $i != $n ) {
3427                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3428                 }
3429                 echo $i;
3430                 flush();
3431                 if ( $i ) {
3432                         sleep( 1 );
3433                 }
3434         }
3435         echo "\n";
3436 }
3437
3438 /**
3439  * Generate a random 32-character hexadecimal token.
3440  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3441  *              characters before hashing.
3442  * @return string
3443  * @codeCoverageIgnore
3444  */
3445 function wfGenerateToken( $salt = '' ) {
3446         $salt = serialize( $salt );
3447         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3448 }
3449
3450 /**
3451  * Replace all invalid characters with -
3452  *
3453  * @param $name Mixed: filename to process
3454  * @return String
3455  */
3456 function wfStripIllegalFilenameChars( $name ) {
3457         global $wgIllegalFileChars;
3458         $name = wfBaseName( $name );
3459         $name = preg_replace(
3460                 "/[^" . Title::legalChars() . "]" .
3461                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3462                         "/",
3463                 '-',
3464                 $name
3465         );
3466         return $name;
3467 }
3468
3469 /**
3470  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3471  *
3472  * @return Integer value memory was set to.
3473  */
3474 function wfMemoryLimit() {
3475         global $wgMemoryLimit;
3476         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3477         if( $memlimit != -1 ) {
3478                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3479                 if( $conflimit == -1 ) {
3480                         wfDebug( "Removing PHP's memory limit\n" );
3481                         wfSuppressWarnings();
3482                         ini_set( 'memory_limit', $conflimit );
3483                         wfRestoreWarnings();
3484                         return $conflimit;
3485                 } elseif ( $conflimit > $memlimit ) {
3486                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3487                         wfSuppressWarnings();
3488                         ini_set( 'memory_limit', $conflimit );
3489                         wfRestoreWarnings();
3490                         return $conflimit;
3491                 }
3492         }
3493         return $memlimit;
3494 }
3495
3496 /**
3497  * Converts shorthand byte notation to integer form
3498  *
3499  * @param $string String
3500  * @return Integer
3501  */
3502 function wfShorthandToInteger( $string = '' ) {
3503         $string = trim( $string );
3504         if( $string === '' ) {
3505                 return -1;
3506         }
3507         $last = $string[strlen( $string ) - 1];
3508         $val = intval( $string );
3509         switch( $last ) {
3510                 case 'g':
3511                 case 'G':
3512                         $val *= 1024;
3513                         // break intentionally missing
3514                 case 'm':
3515                 case 'M':
3516                         $val *= 1024;
3517                         // break intentionally missing
3518                 case 'k':
3519                 case 'K':
3520                         $val *= 1024;
3521         }
3522
3523         return $val;
3524 }
3525
3526 /**
3527  * Get the normalised IETF language tag
3528  * See unit test for examples.
3529  *
3530  * @param $code String: The language code.
3531  * @return $langCode String: The language code which complying with BCP 47 standards.
3532  */
3533 function wfBCP47( $code ) {
3534         $codeSegment = explode( '-', $code );
3535         $codeBCP = array();
3536         foreach ( $codeSegment as $segNo => $seg ) {
3537                 if ( count( $codeSegment ) > 0 ) {
3538                         // when previous segment is x, it is a private segment and should be lc
3539                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3540                                 $codeBCP[$segNo] = strtolower( $seg );
3541                         // ISO 3166 country code
3542                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3543                                 $codeBCP[$segNo] = strtoupper( $seg );
3544                         // ISO 15924 script code
3545                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3546                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3547                         // Use lowercase for other cases
3548                         } else {
3549                                 $codeBCP[$segNo] = strtolower( $seg );
3550                         }
3551                 } else {
3552                 // Use lowercase for single segment
3553                         $codeBCP[$segNo] = strtolower( $seg );
3554                 }
3555         }
3556         $langCode = implode( '-', $codeBCP );
3557         return $langCode;
3558 }
3559
3560 /**
3561  * Get a cache object.
3562  *
3563  * @param $inputType integer Cache type, one the the CACHE_* constants.
3564  * @return BagOStuff
3565  */
3566 function wfGetCache( $inputType ) {
3567         return ObjectCache::getInstance( $inputType );
3568 }
3569
3570 /**
3571  * Get the main cache object
3572  *
3573  * @return BagOStuff
3574  */
3575 function wfGetMainCache() {
3576         global $wgMainCacheType;
3577         return ObjectCache::getInstance( $wgMainCacheType );
3578 }
3579
3580 /**
3581  * Get the cache object used by the message cache
3582  *
3583  * @return BagOStuff
3584  */
3585 function wfGetMessageCacheStorage() {
3586         global $wgMessageCacheType;
3587         return ObjectCache::getInstance( $wgMessageCacheType );
3588 }
3589
3590 /**
3591  * Get the cache object used by the parser cache
3592  *
3593  * @return BagOStuff
3594  */
3595 function wfGetParserCacheStorage() {
3596         global $wgParserCacheType;
3597         return ObjectCache::getInstance( $wgParserCacheType );
3598 }
3599
3600 /**
3601  * Call hook functions defined in $wgHooks
3602  *
3603  * @param $event String: event name
3604  * @param $args Array: parameters passed to hook functions
3605  * @return Boolean
3606  */
3607 function wfRunHooks( $event, $args = array() ) {
3608         return Hooks::run( $event, $args );
3609 }