includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if ( !function_exists( 'mb_substr' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @see Fallback::mb_substr
  42          * @return string
  43          */
  44         function mb_substr( $str, $start, $count = 'end' ) {
  45                 return Fallback::mb_substr( $str, $start, $count );
  46         }
  47
  48         /**
  49          * @codeCoverageIgnore
  50          * @see Fallback::mb_substr_split_unicode
  51          * @return int
  52          */
  53         function mb_substr_split_unicode( $str, $splitPos ) {
  54                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  55         }
  56 }
  57
  58 if ( !function_exists( 'mb_strlen' ) ) {
  59         /**
  60          * @codeCoverageIgnore
  61          * @see Fallback::mb_strlen
  62          * @return int
  63          */
  64         function mb_strlen( $str, $enc = '' ) {
  65                 return Fallback::mb_strlen( $str, $enc );
  66         }
  67 }
  68
  69 if ( !function_exists( 'mb_strpos' ) ) {
  70         /**
  71          * @codeCoverageIgnore
  72          * @see Fallback::mb_strpos
  73          * @return int
  74          */
  75         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  76                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  77         }
  78 }
  79
  80 if ( !function_exists( 'mb_strrpos' ) ) {
  81         /**
  82          * @codeCoverageIgnore
  83          * @see Fallback::mb_strrpos
  84          * @return int
  85          */
  86         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  87                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  88         }
  89 }
  90
  91 // gzdecode function only exists in PHP >= 5.4.0
  92 // http://php.net/gzdecode
  93 if ( !function_exists( 'gzdecode' ) ) {
  94         /**
  95          * @codeCoverageIgnore
  96          * @param string $data
  97          * @return string
  98          */
  99         function gzdecode( $data ) {
 100                 return gzinflate( substr( $data, 10, -8 ) );
 101         }
 102 }
 103
 104 // hash_equals function only exists in PHP >= 5.6.0
 105 if ( !function_exists( 'hash_equals' ) ) {
 106         /**
 107          * Check whether a user-provided string is equal to a fixed-length secret without
 108          * revealing bytes of the secret through timing differences.
 109          *
 110          * This timing guarantee -- that a partial match takes the same time as a complete
 111          * mismatch -- is why this function is used in some security-sensitive parts of the code.
 112          * For example, it shouldn't be possible to guess an HMAC signature one byte at a time.
 113          *
 114          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 115          *
 116          * @codeCoverageIgnore
 117          * @param string $known_string Fixed-length secret to compare against
 118          * @param string $user_string User-provided string
 119          * @return bool True if the strings are the same, false otherwise
 120          */
 121         function hash_equals( $known_string, $user_string ) {
 122                 // Strict type checking as in PHP's native implementation
 123                 if ( !is_string( $known_string ) ) {
 124                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 125                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 126
 127                         return false;
 128                 }
 129
 130                 if ( !is_string( $user_string ) ) {
 131                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 132                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 133
 134                         return false;
 135                 }
 136
 137                 // Note that we do one thing PHP doesn't: try to avoid leaking information about
 138                 // relative lengths of $known_string and $user_string, and of multiple $known_strings.
 139                 // However, lengths may still inevitably leak through, for example, CPU cache misses.
 140                 $known_string_len = strlen( $known_string );
 141                 $user_string_len = strlen( $user_string );
 142                 $result = $known_string_len ^ $user_string_len;
 143                 for ( $i = 0; $i < $user_string_len; $i++ ) {
 144                         $result |= ord( $known_string[$i % $known_string_len] ) ^ ord( $user_string[$i] );
 145                 }
 146
 147                 return ( $result === 0 );
 148         }
 149 }
 150 /// @endcond
 151
 152 /**
 153  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 154  * @param array $a
 155  * @param array $b
 156  * @return array
 157  */
 158 function wfArrayDiff2( $a, $b ) {
 159         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 160 }
 161
 162 /**
 163  * @param array|string $a
 164  * @param array|string $b
 165  * @return int
 166  */
 167 function wfArrayDiff2_cmp( $a, $b ) {
 168         if ( is_string( $a ) && is_string( $b ) ) {
 169                 return strcmp( $a, $b );
 170         } elseif ( count( $a ) !== count( $b ) ) {
 171                 return count( $a ) < count( $b ) ? -1 : 1;
 172         } else {
 173                 reset( $a );
 174                 reset( $b );
 175                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 176                         $cmp = strcmp( $valueA, $valueB );
 177                         if ( $cmp !== 0 ) {
 178                                 return $cmp;
 179                         }
 180                 }
 181                 return 0;
 182         }
 183 }
 184
 185 /**
 186  * Appends to second array if $value differs from that in $default
 187  *
 188  * @param string|int $key
 189  * @param mixed $value
 190  * @param mixed $default
 191  * @param array $changed Array to alter
 192  * @throws MWException
 193  */
 194 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 195         if ( is_null( $changed ) ) {
 196                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 197         }
 198         if ( $default[$key] !== $value ) {
 199                 $changed[$key] = $value;
 200         }
 201 }
 202
 203 /**
 204  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 205  * e.g.
 206  *      wfMergeErrorArrays(
 207  *              array( array( 'x' ) ),
 208  *              array( array( 'x', '2' ) ),
 209  *              array( array( 'x' ) ),
 210  *              array( array( 'y' ) )
 211  *      );
 212  * returns:
 213  *              array(
 214  *              array( 'x', '2' ),
 215  *              array( 'x' ),
 216  *              array( 'y' )
 217  *      )
 218  *
 219  * @param array $array1,...
 220  * @return array
 221  */
 222 function wfMergeErrorArrays( /*...*/ ) {
 223         $args = func_get_args();
 224         $out = array();
 225         foreach ( $args as $errors ) {
 226                 foreach ( $errors as $params ) {
 227                         # @todo FIXME: Sometimes get nested arrays for $params,
 228                         # which leads to E_NOTICEs
 229                         $spec = implode( "\t", $params );
 230                         $out[$spec] = $params;
 231                 }
 232         }
 233         return array_values( $out );
 234 }
 235
 236 /**
 237  * Insert array into another array after the specified *KEY*
 238  *
 239  * @param array $array The array.
 240  * @param array $insert The array to insert.
 241  * @param mixed $after The key to insert after
 242  * @return array
 243  */
 244 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 245         // Find the offset of the element to insert after.
 246         $keys = array_keys( $array );
 247         $offsetByKey = array_flip( $keys );
 248
 249         $offset = $offsetByKey[$after];
 250
 251         // Insert at the specified offset
 252         $before = array_slice( $array, 0, $offset + 1, true );
 253         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 254
 255         $output = $before + $insert + $after;
 256
 257         return $output;
 258 }
 259
 260 /**
 261  * Recursively converts the parameter (an object) to an array with the same data
 262  *
 263  * @param object|array $objOrArray
 264  * @param bool $recursive
 265  * @return array
 266  */
 267 function wfObjectToArray( $objOrArray, $recursive = true ) {
 268         $array = array();
 269         if ( is_object( $objOrArray ) ) {
 270                 $objOrArray = get_object_vars( $objOrArray );
 271         }
 272         foreach ( $objOrArray as $key => $value ) {
 273                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 274                         $value = wfObjectToArray( $value );
 275                 }
 276
 277                 $array[$key] = $value;
 278         }
 279
 280         return $array;
 281 }
 282
 283 /**
 284  * Get a random decimal value between 0 and 1, in a way
 285  * not likely to give duplicate values for any realistic
 286  * number of articles.
 287  *
 288  * @return string
 289  */
 290 function wfRandom() {
 291         # The maximum random value is "only" 2^31-1, so get two random
 292         # values to reduce the chance of dupes
 293         $max = mt_getrandmax() + 1;
 294         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 295
 296         return $rand;
 297 }
 298
 299 /**
 300  * Get a random string containing a number of pseudo-random hex
 301  * characters.
 302  * @note This is not secure, if you are trying to generate some sort
 303  *       of token please use MWCryptRand instead.
 304  *
 305  * @param int $length The length of the string to generate
 306  * @return string
 307  * @since 1.20
 308  */
 309 function wfRandomString( $length = 32 ) {
 310         $str = '';
 311         for ( $n = 0; $n < $length; $n += 7 ) {
 312                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 313         }
 314         return substr( $str, 0, $length );
 315 }
 316
 317 /**
 318  * We want some things to be included as literal characters in our title URLs
 319  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 320  * all of the following should be safe:
 321  *
 322  * ;:@&=$-_.+!*'(),
 323  *
 324  * But + is not safe because it's used to indicate a space; &= are only safe in
 325  * paths and not in queries (and we don't distinguish here); ' seems kind of
 326  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 327  * is reserved, we don't care.  So the list we unescape is:
 328  *
 329  * ;:@$!*(),/
 330  *
 331  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 332  * so no fancy : for IIS7.
 333  *
 334  * %2F in the page titles seems to fatally break for some reason.
 335  *
 336  * @param string $s
 337  * @return string
 338  */
 339 function wfUrlencode( $s ) {
 340         static $needle;
 341
 342         if ( is_null( $s ) ) {
 343                 $needle = null;
 344                 return '';
 345         }
 346
 347         if ( is_null( $needle ) ) {
 348                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 349                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 350                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 351                 ) {
 352                         $needle[] = '%3A';
 353                 }
 354         }
 355
 356         $s = urlencode( $s );
 357         $s = str_ireplace(
 358                 $needle,
 359                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 360                 $s
 361         );
 362
 363         return $s;
 364 }
 365
 366 /**
 367  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 368  * "days=7&limit=100". Options in the first array override options in the second.
 369  * Options set to null or false will not be output.
 370  *
 371  * @param array $array1 ( String|Array )
 372  * @param array $array2 ( String|Array )
 373  * @param string $prefix
 374  * @return string
 375  */
 376 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 377         if ( !is_null( $array2 ) ) {
 378                 $array1 = $array1 + $array2;
 379         }
 380
 381         $cgi = '';
 382         foreach ( $array1 as $key => $value ) {
 383                 if ( !is_null( $value ) && $value !== false ) {
 384                         if ( $cgi != '' ) {
 385                                 $cgi .= '&';
 386                         }
 387                         if ( $prefix !== '' ) {
 388                                 $key = $prefix . "[$key]";
 389                         }
 390                         if ( is_array( $value ) ) {
 391                                 $firstTime = true;
 392                                 foreach ( $value as $k => $v ) {
 393                                         $cgi .= $firstTime ? '' : '&';
 394                                         if ( is_array( $v ) ) {
 395                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 396                                         } else {
 397                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 398                                         }
 399                                         $firstTime = false;
 400                                 }
 401                         } else {
 402                                 if ( is_object( $value ) ) {
 403                                         $value = $value->__toString();
 404                                 }
 405                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 406                         }
 407                 }
 408         }
 409         return $cgi;
 410 }
 411
 412 /**
 413  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 414  * its argument and returns the same string in array form.  This allows compatibility
 415  * with legacy functions that accept raw query strings instead of nice
 416  * arrays.  Of course, keys and values are urldecode()d.
 417  *
 418  * @param string $query Query string
 419  * @return string[] Array version of input
 420  */
 421 function wfCgiToArray( $query ) {
 422         if ( isset( $query[0] ) && $query[0] == '?' ) {
 423                 $query = substr( $query, 1 );
 424         }
 425         $bits = explode( '&', $query );
 426         $ret = array();
 427         foreach ( $bits as $bit ) {
 428                 if ( $bit === '' ) {
 429                         continue;
 430                 }
 431                 if ( strpos( $bit, '=' ) === false ) {
 432                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 433                         $key = $bit;
 434                         $value = '';
 435                 } else {
 436                         list( $key, $value ) = explode( '=', $bit );
 437                 }
 438                 $key = urldecode( $key );
 439                 $value = urldecode( $value );
 440                 if ( strpos( $key, '[' ) !== false ) {
 441                         $keys = array_reverse( explode( '[', $key ) );
 442                         $key = array_pop( $keys );
 443                         $temp = $value;
 444                         foreach ( $keys as $k ) {
 445                                 $k = substr( $k, 0, -1 );
 446                                 $temp = array( $k => $temp );
 447                         }
 448                         if ( isset( $ret[$key] ) ) {
 449                                 $ret[$key] = array_merge( $ret[$key], $temp );
 450                         } else {
 451                                 $ret[$key] = $temp;
 452                         }
 453                 } else {
 454                         $ret[$key] = $value;
 455                 }
 456         }
 457         return $ret;
 458 }
 459
 460 /**
 461  * Append a query string to an existing URL, which may or may not already
 462  * have query string parameters already. If so, they will be combined.
 463  *
 464  * @param string $url
 465  * @param string|string[] $query String or associative array
 466  * @return string
 467  */
 468 function wfAppendQuery( $url, $query ) {
 469         if ( is_array( $query ) ) {
 470                 $query = wfArrayToCgi( $query );
 471         }
 472         if ( $query != '' ) {
 473                 if ( false === strpos( $url, '?' ) ) {
 474                         $url .= '?';
 475                 } else {
 476                         $url .= '&';
 477                 }
 478                 $url .= $query;
 479         }
 480         return $url;
 481 }
 482
 483 /**
 484  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 485  * is correct.
 486  *
 487  * The meaning of the PROTO_* constants is as follows:
 488  * PROTO_HTTP: Output a URL starting with http://
 489  * PROTO_HTTPS: Output a URL starting with https://
 490  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 491  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 492  *    on which protocol was used for the current incoming request
 493  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 494  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 495  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 496  *
 497  * @todo this won't work with current-path-relative URLs
 498  * like "subdir/foo.html", etc.
 499  *
 500  * @param string $url Either fully-qualified or a local path + query
 501  * @param string $defaultProto One of the PROTO_* constants. Determines the
 502  *    protocol to use if $url or $wgServer is protocol-relative
 503  * @return string Fully-qualified URL, current-path-relative URL or false if
 504  *    no valid URL can be constructed
 505  */
 506 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 507         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 508                 $wgHttpsPort;
 509         if ( $defaultProto === PROTO_CANONICAL ) {
 510                 $serverUrl = $wgCanonicalServer;
 511         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 512                 // Make $wgInternalServer fall back to $wgServer if not set
 513                 $serverUrl = $wgInternalServer;
 514         } else {
 515                 $serverUrl = $wgServer;
 516                 if ( $defaultProto === PROTO_CURRENT ) {
 517                         $defaultProto = $wgRequest->getProtocol() . '://';
 518                 }
 519         }
 520
 521         // Analyze $serverUrl to obtain its protocol
 522         $bits = wfParseUrl( $serverUrl );
 523         $serverHasProto = $bits && $bits['scheme'] != '';
 524
 525         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 526                 if ( $serverHasProto ) {
 527                         $defaultProto = $bits['scheme'] . '://';
 528                 } else {
 529                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 530                         // This really isn't supposed to happen. Fall back to HTTP in this
 531                         // ridiculous case.
 532                         $defaultProto = PROTO_HTTP;
 533                 }
 534         }
 535
 536         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 537
 538         if ( substr( $url, 0, 2 ) == '//' ) {
 539                 $url = $defaultProtoWithoutSlashes . $url;
 540         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 541                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 542                 // otherwise leave it alone.
 543                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 544         }
 545
 546         $bits = wfParseUrl( $url );
 547
 548         // ensure proper port for HTTPS arrives in URL
 549         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 550         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 551                 $bits['port'] = $wgHttpsPort;
 552         }
 553
 554         if ( $bits && isset( $bits['path'] ) ) {
 555                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 556                 return wfAssembleUrl( $bits );
 557         } elseif ( $bits ) {
 558                 # No path to expand
 559                 return $url;
 560         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 561                 # URL is a relative path
 562                 return wfRemoveDotSegments( $url );
 563         }
 564
 565         # Expanded URL is not valid.
 566         return false;
 567 }
 568
 569 /**
 570  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 571  * if you need to edit part of a URL and put it back together.
 572  *
 573  * This is the basic structure used (brackets contain keys for $urlParts):
 574  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 575  *
 576  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 577  *
 578  * @since 1.19
 579  * @param array $urlParts URL parts, as output from wfParseUrl
 580  * @return string URL assembled from its component parts
 581  */
 582 function wfAssembleUrl( $urlParts ) {
 583         $result = '';
 584
 585         if ( isset( $urlParts['delimiter'] ) ) {
 586                 if ( isset( $urlParts['scheme'] ) ) {
 587                         $result .= $urlParts['scheme'];
 588                 }
 589
 590                 $result .= $urlParts['delimiter'];
 591         }
 592
 593         if ( isset( $urlParts['host'] ) ) {
 594                 if ( isset( $urlParts['user'] ) ) {
 595                         $result .= $urlParts['user'];
 596                         if ( isset( $urlParts['pass'] ) ) {
 597                                 $result .= ':' . $urlParts['pass'];
 598                         }
 599                         $result .= '@';
 600                 }
 601
 602                 $result .= $urlParts['host'];
 603
 604                 if ( isset( $urlParts['port'] ) ) {
 605                         $result .= ':' . $urlParts['port'];
 606                 }
 607         }
 608
 609         if ( isset( $urlParts['path'] ) ) {
 610                 $result .= $urlParts['path'];
 611         }
 612
 613         if ( isset( $urlParts['query'] ) ) {
 614                 $result .= '?' . $urlParts['query'];
 615         }
 616
 617         if ( isset( $urlParts['fragment'] ) ) {
 618                 $result .= '#' . $urlParts['fragment'];
 619         }
 620
 621         return $result;
 622 }
 623
 624 /**
 625  * Remove all dot-segments in the provided URL path.  For example,
 626  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 627  * RFC3986 section 5.2.4.
 628  *
 629  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 630  *
 631  * @param string $urlPath URL path, potentially containing dot-segments
 632  * @return string URL path with all dot-segments removed
 633  */
 634 function wfRemoveDotSegments( $urlPath ) {
 635         $output = '';
 636         $inputOffset = 0;
 637         $inputLength = strlen( $urlPath );
 638
 639         while ( $inputOffset < $inputLength ) {
 640                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 641                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 642                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 643                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 644                 $trimOutput = false;
 645
 646                 if ( $prefixLengthTwo == './' ) {
 647                         # Step A, remove leading "./"
 648                         $inputOffset += 2;
 649                 } elseif ( $prefixLengthThree == '../' ) {
 650                         # Step A, remove leading "../"
 651                         $inputOffset += 3;
 652                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 653                         # Step B, replace leading "/.$" with "/"
 654                         $inputOffset += 1;
 655                         $urlPath[$inputOffset] = '/';
 656                 } elseif ( $prefixLengthThree == '/./' ) {
 657                         # Step B, replace leading "/./" with "/"
 658                         $inputOffset += 2;
 659                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 660                         # Step C, replace leading "/..$" with "/" and
 661                         # remove last path component in output
 662                         $inputOffset += 2;
 663                         $urlPath[$inputOffset] = '/';
 664                         $trimOutput = true;
 665                 } elseif ( $prefixLengthFour == '/../' ) {
 666                         # Step C, replace leading "/../" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 3;
 669                         $trimOutput = true;
 670                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 671                         # Step D, remove "^.$"
 672                         $inputOffset += 1;
 673                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 674                         # Step D, remove "^..$"
 675                         $inputOffset += 2;
 676                 } else {
 677                         # Step E, move leading path segment to output
 678                         if ( $prefixLengthOne == '/' ) {
 679                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 680                         } else {
 681                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 682                         }
 683                         if ( $slashPos === false ) {
 684                                 $output .= substr( $urlPath, $inputOffset );
 685                                 $inputOffset = $inputLength;
 686                         } else {
 687                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 688                                 $inputOffset += $slashPos - $inputOffset;
 689                         }
 690                 }
 691
 692                 if ( $trimOutput ) {
 693                         $slashPos = strrpos( $output, '/' );
 694                         if ( $slashPos === false ) {
 695                                 $output = '';
 696                         } else {
 697                                 $output = substr( $output, 0, $slashPos );
 698                         }
 699                 }
 700         }
 701
 702         return $output;
 703 }
 704
 705 /**
 706  * Returns a regular expression of url protocols
 707  *
 708  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 709  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 710  * @return string
 711  */
 712 function wfUrlProtocols( $includeProtocolRelative = true ) {
 713         global $wgUrlProtocols;
 714
 715         // Cache return values separately based on $includeProtocolRelative
 716         static $withProtRel = null, $withoutProtRel = null;
 717         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 718         if ( !is_null( $cachedValue ) ) {
 719                 return $cachedValue;
 720         }
 721
 722         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 723         // with LocalSettings files from 1.5
 724         if ( is_array( $wgUrlProtocols ) ) {
 725                 $protocols = array();
 726                 foreach ( $wgUrlProtocols as $protocol ) {
 727                         // Filter out '//' if !$includeProtocolRelative
 728                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 729                                 $protocols[] = preg_quote( $protocol, '/' );
 730                         }
 731                 }
 732
 733                 $retval = implode( '|', $protocols );
 734         } else {
 735                 // Ignore $includeProtocolRelative in this case
 736                 // This case exists for pre-1.6 compatibility, and we can safely assume
 737                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 738                 // URLs weren't supported until 1.18
 739                 $retval = $wgUrlProtocols;
 740         }
 741
 742         // Cache return value
 743         if ( $includeProtocolRelative ) {
 744                 $withProtRel = $retval;
 745         } else {
 746                 $withoutProtRel = $retval;
 747         }
 748         return $retval;
 749 }
 750
 751 /**
 752  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 753  * you need a regex that matches all URL protocols but does not match protocol-
 754  * relative URLs
 755  * @return string
 756  */
 757 function wfUrlProtocolsWithoutProtRel() {
 758         return wfUrlProtocols( false );
 759 }
 760
 761 /**
 762  * parse_url() work-alike, but non-broken.  Differences:
 763  *
 764  * 1) Does not raise warnings on bad URLs (just returns false).
 765  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 766  *    protocol-relative URLs) correctly.
 767  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 768  *
 769  * @param string $url A URL to parse
 770  * @return string[] Bits of the URL in an associative array, per PHP docs
 771  */
 772 function wfParseUrl( $url ) {
 773         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 774
 775         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 776         // bad that the easiest way to handle them is to just prepend 'http:' and
 777         // strip the protocol out later.
 778         $wasRelative = substr( $url, 0, 2 ) == '//';
 779         if ( $wasRelative ) {
 780                 $url = "http:$url";
 781         }
 782         wfSuppressWarnings();
 783         $bits = parse_url( $url );
 784         wfRestoreWarnings();
 785         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 786         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 787         if ( !$bits || !isset( $bits['scheme'] ) ) {
 788                 return false;
 789         }
 790
 791         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 792         $bits['scheme'] = strtolower( $bits['scheme'] );
 793
 794         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 795         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 796                 $bits['delimiter'] = '://';
 797         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 798                 $bits['delimiter'] = ':';
 799                 // parse_url detects for news: and mailto: the host part of an url as path
 800                 // We have to correct this wrong detection
 801                 if ( isset( $bits['path'] ) ) {
 802                         $bits['host'] = $bits['path'];
 803                         $bits['path'] = '';
 804                 }
 805         } else {
 806                 return false;
 807         }
 808
 809         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 810         if ( !isset( $bits['host'] ) ) {
 811                 $bits['host'] = '';
 812
 813                 // bug 45069
 814                 if ( isset( $bits['path'] ) ) {
 815                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 816                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 817                                 $bits['path'] = '/' . $bits['path'];
 818                         }
 819                 } else {
 820                         $bits['path'] = '';
 821                 }
 822         }
 823
 824         // If the URL was protocol-relative, fix scheme and delimiter
 825         if ( $wasRelative ) {
 826                 $bits['scheme'] = '';
 827                 $bits['delimiter'] = '//';
 828         }
 829         return $bits;
 830 }
 831
 832 /**
 833  * Take a URL, make sure it's expanded to fully qualified, and replace any
 834  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 835  * for more compact display and legibility for local audiences.
 836  *
 837  * @todo handle punycode domains too
 838  *
 839  * @param string $url
 840  * @return string
 841  */
 842 function wfExpandIRI( $url ) {
 843         return preg_replace_callback(
 844                 '/((?:%[89A-F][0-9A-F])+)/i',
 845                 'wfExpandIRI_callback',
 846                 wfExpandUrl( $url )
 847         );
 848 }
 849
 850 /**
 851  * Private callback for wfExpandIRI
 852  * @param array $matches
 853  * @return string
 854  */
 855 function wfExpandIRI_callback( $matches ) {
 856         return urldecode( $matches[1] );
 857 }
 858
 859 /**
 860  * Make URL indexes, appropriate for the el_index field of externallinks.
 861  *
 862  * @param string $url
 863  * @return array
 864  */
 865 function wfMakeUrlIndexes( $url ) {
 866         $bits = wfParseUrl( $url );
 867
 868         // Reverse the labels in the hostname, convert to lower case
 869         // For emails reverse domainpart only
 870         if ( $bits['scheme'] == 'mailto' ) {
 871                 $mailparts = explode( '@', $bits['host'], 2 );
 872                 if ( count( $mailparts ) === 2 ) {
 873                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 874                 } else {
 875                         // No domain specified, don't mangle it
 876                         $domainpart = '';
 877                 }
 878                 $reversedHost = $domainpart . '@' . $mailparts[0];
 879         } else {
 880                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 881         }
 882         // Add an extra dot to the end
 883         // Why? Is it in wrong place in mailto links?
 884         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 885                 $reversedHost .= '.';
 886         }
 887         // Reconstruct the pseudo-URL
 888         $prot = $bits['scheme'];
 889         $index = $prot . $bits['delimiter'] . $reversedHost;
 890         // Leave out user and password. Add the port, path, query and fragment
 891         if ( isset( $bits['port'] ) ) {
 892                 $index .= ':' . $bits['port'];
 893         }
 894         if ( isset( $bits['path'] ) ) {
 895                 $index .= $bits['path'];
 896         } else {
 897                 $index .= '/';
 898         }
 899         if ( isset( $bits['query'] ) ) {
 900                 $index .= '?' . $bits['query'];
 901         }
 902         if ( isset( $bits['fragment'] ) ) {
 903                 $index .= '#' . $bits['fragment'];
 904         }
 905
 906         if ( $prot == '' ) {
 907                 return array( "http:$index", "https:$index" );
 908         } else {
 909                 return array( $index );
 910         }
 911 }
 912
 913 /**
 914  * Check whether a given URL has a domain that occurs in a given set of domains
 915  * @param string $url URL
 916  * @param array $domains Array of domains (strings)
 917  * @return bool True if the host part of $url ends in one of the strings in $domains
 918  */
 919 function wfMatchesDomainList( $url, $domains ) {
 920         $bits = wfParseUrl( $url );
 921         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 922                 $host = '.' . $bits['host'];
 923                 foreach ( (array)$domains as $domain ) {
 924                         $domain = '.' . $domain;
 925                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 926                                 return true;
 927                         }
 928                 }
 929         }
 930         return false;
 931 }
 932
 933 /**
 934  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 935  * In normal operation this is a NOP.
 936  *
 937  * Controlling globals:
 938  * $wgDebugLogFile - points to the log file
 939  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 940  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 941  *
 942  * @param string $text
 943  * @param string|bool $dest Destination of the message:
 944  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 945  *     - 'log': only to the log and not in HTML
 946  *   For backward compatibility, it can also take a boolean:
 947  *     - true: same as 'all'
 948  *     - false: same as 'log'
 949  */
 950 function wfDebug( $text, $dest = 'all' ) {
 951         global $wgDebugLogFile, $wgDebugRawPage, $wgDebugLogPrefix;
 952
 953         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 954                 return;
 955         }
 956
 957         // Turn $dest into a string if it's a boolean (for b/c)
 958         if ( $dest === true ) {
 959                 $dest = 'all';
 960         } elseif ( $dest === false ) {
 961                 $dest = 'log';
 962         }
 963
 964         $timer = wfDebugTimer();
 965         if ( $timer !== '' ) {
 966                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 967         }
 968
 969         if ( $dest === 'all' ) {
 970                 MWDebug::debugMsg( $text );
 971         }
 972
 973         if ( $wgDebugLogFile != '' ) {
 974                 # Strip unprintables; they can switch terminal modes when binary data
 975                 # gets dumped, which is pretty annoying.
 976                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 977                 $text = $wgDebugLogPrefix . $text;
 978                 wfErrorLog( $text, $wgDebugLogFile );
 979         }
 980 }
 981
 982 /**
 983  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 984  * @return bool
 985  */
 986 function wfIsDebugRawPage() {
 987         static $cache;
 988         if ( $cache !== null ) {
 989                 return $cache;
 990         }
 991         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 992         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 993                 || (
 994                         isset( $_SERVER['SCRIPT_NAME'] )
 995                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 996                 )
 997         ) {
 998                 $cache = true;
 999         } else {
1000                 $cache = false;
1001         }
1002         return $cache;
1003 }
1004
1005 /**
1006  * Get microsecond timestamps for debug logs
1007  *
1008  * @return string
1009  */
1010 function wfDebugTimer() {
1011         global $wgDebugTimestamps, $wgRequestTime;
1012
1013         if ( !$wgDebugTimestamps ) {
1014                 return '';
1015         }
1016
1017         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1018         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1019         return "$prefix $mem  ";
1020 }
1021
1022 /**
1023  * Send a line giving PHP memory usage.
1024  *
1025  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1026  */
1027 function wfDebugMem( $exact = false ) {
1028         $mem = memory_get_usage();
1029         if ( !$exact ) {
1030                 $mem = floor( $mem / 1024 ) . ' KiB';
1031         } else {
1032                 $mem .= ' B';
1033         }
1034         wfDebug( "Memory usage: $mem\n" );
1035 }
1036
1037 /**
1038  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1039  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1040  * filename or an associative array mapping 'destination' to the desired filename. The
1041  * associative array may also contain a 'sample' key with an integer value, specifying
1042  * a sampling factor.
1043  *
1044  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1045  *
1046  * @param string $logGroup
1047  * @param string $text
1048  * @param string|bool $dest Destination of the message:
1049  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1050  *     - 'log': only to the log and not in HTML
1051  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1052  *       discarded otherwise
1053  *   For backward compatibility, it can also take a boolean:
1054  *     - true: same as 'all'
1055  *     - false: same as 'private'
1056  */
1057 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1058         global $wgDebugLogGroups;
1059
1060         $text = trim( $text ) . "\n";
1061
1062         // Turn $dest into a string if it's a boolean (for b/c)
1063         if ( $dest === true ) {
1064                 $dest = 'all';
1065         } elseif ( $dest === false ) {
1066                 $dest = 'private';
1067         }
1068
1069         if ( !isset( $wgDebugLogGroups[$logGroup] ) ) {
1070                 if ( $dest !== 'private' ) {
1071                         wfDebug( "[$logGroup] $text", $dest );
1072                 }
1073                 return;
1074         }
1075
1076         if ( $dest === 'all' ) {
1077                 MWDebug::debugMsg( "[$logGroup] $text" );
1078         }
1079
1080         $logConfig = $wgDebugLogGroups[$logGroup];
1081         if ( $logConfig === false ) {
1082                 return;
1083         }
1084         if ( is_array( $logConfig ) ) {
1085                 if ( isset( $logConfig['sample'] ) && mt_rand( 1, $logConfig['sample'] ) !== 1 ) {
1086                         return;
1087                 }
1088                 $destination = $logConfig['destination'];
1089         } else {
1090                 $destination = strval( $logConfig );
1091         }
1092
1093         $time = wfTimestamp( TS_DB );
1094         $wiki = wfWikiID();
1095         $host = wfHostname();
1096         wfErrorLog( "$time $host $wiki: $text", $destination );
1097 }
1098
1099 /**
1100  * Log for database errors
1101  *
1102  * @param string $text Database error message.
1103  */
1104 function wfLogDBError( $text ) {
1105         global $wgDBerrorLog, $wgDBerrorLogTZ;
1106         static $logDBErrorTimeZoneObject = null;
1107
1108         if ( $wgDBerrorLog ) {
1109                 $host = wfHostname();
1110                 $wiki = wfWikiID();
1111
1112                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1113                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1114                 }
1115
1116                 // Workaround for https://bugs.php.net/bug.php?id=52063
1117                 // Can be removed when min PHP > 5.3.2
1118                 if ( $logDBErrorTimeZoneObject === null ) {
1119                         $d = date_create( "now" );
1120                 } else {
1121                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1122                 }
1123
1124                 $date = $d->format( 'D M j G:i:s T Y' );
1125
1126                 $text = "$date\t$host\t$wiki\t" . trim( $text ) . "\n";
1127                 wfErrorLog( $text, $wgDBerrorLog );
1128         }
1129 }
1130
1131 /**
1132  * Throws a warning that $function is deprecated
1133  *
1134  * @param string $function
1135  * @param string|bool $version Version of MediaWiki that the function
1136  *    was deprecated in (Added in 1.19).
1137  * @param string|bool $component Added in 1.19.
1138  * @param int $callerOffset How far up the call stack is the original
1139  *    caller. 2 = function that called the function that called
1140  *    wfDeprecated (Added in 1.20)
1141  *
1142  * @return null
1143  */
1144 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1145         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1146 }
1147
1148 /**
1149  * Send a warning either to the debug log or in a PHP error depending on
1150  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1151  *
1152  * @param string $msg Message to send
1153  * @param int $callerOffset Number of items to go back in the backtrace to
1154  *        find the correct caller (1 = function calling wfWarn, ...)
1155  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1156  *        only used when $wgDevelopmentWarnings is true
1157  */
1158 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1159         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1160 }
1161
1162 /**
1163  * Send a warning as a PHP error and the debug log. This is intended for logging
1164  * warnings in production. For logging development warnings, use WfWarn instead.
1165  *
1166  * @param string $msg Message to send
1167  * @param int $callerOffset Number of items to go back in the backtrace to
1168  *        find the correct caller (1 = function calling wfLogWarning, ...)
1169  * @param int $level PHP error level; defaults to E_USER_WARNING
1170  */
1171 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1172         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1173 }
1174
1175 /**
1176  * Log to a file without getting "file size exceeded" signals.
1177  *
1178  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1179  * send lines to the specified port, prefixed by the specified prefix and a space.
1180  *
1181  * @param string $text
1182  * @param string $file Filename
1183  * @throws MWException
1184  */
1185 function wfErrorLog( $text, $file ) {
1186         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1187                 # Needs the sockets extension
1188                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1189                         // IPv6 bracketed host
1190                         $host = $m[2];
1191                         $port = intval( $m[3] );
1192                         $prefix = isset( $m[4] ) ? $m[4] : false;
1193                         $domain = AF_INET6;
1194                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1195                         $host = $m[2];
1196                         if ( !IP::isIPv4( $host ) ) {
1197                                 $host = gethostbyname( $host );
1198                         }
1199                         $port = intval( $m[3] );
1200                         $prefix = isset( $m[4] ) ? $m[4] : false;
1201                         $domain = AF_INET;
1202                 } else {
1203                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1204                 }
1205
1206                 // Clean it up for the multiplexer
1207                 if ( strval( $prefix ) !== '' ) {
1208                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1209
1210                         // Limit to 64KB
1211                         if ( strlen( $text ) > 65506 ) {
1212                                 $text = substr( $text, 0, 65506 );
1213                         }
1214
1215                         if ( substr( $text, -1 ) != "\n" ) {
1216                                 $text .= "\n";
1217                         }
1218                 } elseif ( strlen( $text ) > 65507 ) {
1219                         $text = substr( $text, 0, 65507 );
1220                 }
1221
1222                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1223                 if ( !$sock ) {
1224                         return;
1225                 }
1226
1227                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1228                 socket_close( $sock );
1229         } else {
1230                 wfSuppressWarnings();
1231                 $exists = file_exists( $file );
1232                 $size = $exists ? filesize( $file ) : false;
1233                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1234                         file_put_contents( $file, $text, FILE_APPEND );
1235                 }
1236                 wfRestoreWarnings();
1237         }
1238 }
1239
1240 /**
1241  * @todo document
1242  */
1243 function wfLogProfilingData() {
1244         global $wgRequestTime, $wgDebugLogFile, $wgDebugLogGroups, $wgDebugRawPage;
1245         global $wgProfileLimit, $wgUser, $wgRequest;
1246
1247         StatCounter::singleton()->flush();
1248
1249         $profiler = Profiler::instance();
1250
1251         # Profiling must actually be enabled...
1252         if ( $profiler->isStub() ) {
1253                 return;
1254         }
1255
1256         // Get total page request time and only show pages that longer than
1257         // $wgProfileLimit time (default is 0)
1258         $elapsed = microtime( true ) - $wgRequestTime;
1259         if ( $elapsed <= $wgProfileLimit ) {
1260                 return;
1261         }
1262
1263         $profiler->logData();
1264
1265         // Check whether this should be logged in the debug file.
1266         if ( isset( $wgDebugLogGroups['profileoutput'] )
1267                 && $wgDebugLogGroups['profileoutput'] === false
1268         ) {
1269                 // Explicitely disabled
1270                 return;
1271         }
1272         if ( !isset( $wgDebugLogGroups['profileoutput'] ) && $wgDebugLogFile == '' ) {
1273                 // Logging not enabled; no point going further
1274                 return;
1275         }
1276         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1277                 return;
1278         }
1279
1280         $forward = '';
1281         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1282                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1283         }
1284         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1285                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1286         }
1287         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1288                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1289         }
1290         if ( $forward ) {
1291                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1292         }
1293         // Don't load $wgUser at this late stage just for statistics purposes
1294         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1295         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1296                 $forward .= ' anon';
1297         }
1298
1299         // Command line script uses a FauxRequest object which does not have
1300         // any knowledge about an URL and throw an exception instead.
1301         try {
1302                 $requestUrl = $wgRequest->getRequestURL();
1303         } catch ( MWException $e ) {
1304                 $requestUrl = 'n/a';
1305         }
1306
1307         $log = sprintf( "%s\t%04.3f\t%s\n",
1308                 gmdate( 'YmdHis' ), $elapsed,
1309                 urldecode( $requestUrl . $forward ) );
1310
1311         wfDebugLog( 'profileoutput', $log . $profiler->getOutput() );
1312 }
1313
1314 /**
1315  * Increment a statistics counter
1316  *
1317  * @param string $key
1318  * @param int $count
1319  * @return void
1320  */
1321 function wfIncrStats( $key, $count = 1 ) {
1322         StatCounter::singleton()->incr( $key, $count );
1323 }
1324
1325 /**
1326  * Check whether the wiki is in read-only mode.
1327  *
1328  * @return bool
1329  */
1330 function wfReadOnly() {
1331         return wfReadOnlyReason() !== false;
1332 }
1333
1334 /**
1335  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1336  *
1337  * @return string|bool String when in read-only mode; false otherwise
1338  */
1339 function wfReadOnlyReason() {
1340         global $wgReadOnly, $wgReadOnlyFile;
1341
1342         if ( $wgReadOnly === null ) {
1343                 // Set $wgReadOnly for faster access next time
1344                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1345                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1346                 } else {
1347                         $wgReadOnly = false;
1348                 }
1349         }
1350
1351         return $wgReadOnly;
1352 }
1353
1354 /**
1355  * Return a Language object from $langcode
1356  *
1357  * @param Language|string|bool $langcode Either:
1358  *                  - a Language object
1359  *                  - code of the language to get the message for, if it is
1360  *                    a valid code create a language for that language, if
1361  *                    it is a string but not a valid code then make a basic
1362  *                    language object
1363  *                  - a boolean: if it's false then use the global object for
1364  *                    the current user's language (as a fallback for the old parameter
1365  *                    functionality), or if it is true then use global object
1366  *                    for the wiki's content language.
1367  * @return Language
1368  */
1369 function wfGetLangObj( $langcode = false ) {
1370         # Identify which language to get or create a language object for.
1371         # Using is_object here due to Stub objects.
1372         if ( is_object( $langcode ) ) {
1373                 # Great, we already have the object (hopefully)!
1374                 return $langcode;
1375         }
1376
1377         global $wgContLang, $wgLanguageCode;
1378         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1379                 # $langcode is the language code of the wikis content language object.
1380                 # or it is a boolean and value is true
1381                 return $wgContLang;
1382         }
1383
1384         global $wgLang;
1385         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1386                 # $langcode is the language code of user language object.
1387                 # or it was a boolean and value is false
1388                 return $wgLang;
1389         }
1390
1391         $validCodes = array_keys( Language::fetchLanguageNames() );
1392         if ( in_array( $langcode, $validCodes ) ) {
1393                 # $langcode corresponds to a valid language.
1394                 return Language::factory( $langcode );
1395         }
1396
1397         # $langcode is a string, but not a valid language code; use content language.
1398         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1399         return $wgContLang;
1400 }
1401
1402 /**
1403  * This is the function for getting translated interface messages.
1404  *
1405  * @see Message class for documentation how to use them.
1406  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1407  *
1408  * This function replaces all old wfMsg* functions.
1409  *
1410  * @param string|string[] $key Message key, or array of keys
1411  * @param mixed $params,... Normal message parameters
1412  * @return Message
1413  *
1414  * @since 1.17
1415  *
1416  * @see Message::__construct
1417  */
1418 function wfMessage( $key /*...*/ ) {
1419         $params = func_get_args();
1420         array_shift( $params );
1421         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1422                 $params = $params[0];
1423         }
1424         return new Message( $key, $params );
1425 }
1426
1427 /**
1428  * This function accepts multiple message keys and returns a message instance
1429  * for the first message which is non-empty. If all messages are empty then an
1430  * instance of the first message key is returned.
1431  *
1432  * @param string|string[] $keys,... Message keys
1433  * @return Message
1434  *
1435  * @since 1.18
1436  *
1437  * @see Message::newFallbackSequence
1438  */
1439 function wfMessageFallback( /*...*/ ) {
1440         $args = func_get_args();
1441         return call_user_func_array( 'Message::newFallbackSequence', $args );
1442 }
1443
1444 /**
1445  * Get a message from anywhere, for the current user language.
1446  *
1447  * Use wfMsgForContent() instead if the message should NOT
1448  * change depending on the user preferences.
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param string $key Lookup key for the message, usually
1453  *    defined in languages/Language.php
1454  *
1455  * Parameters to the message, which can be used to insert variable text into
1456  * it, can be passed to this function in the following formats:
1457  * - One per argument, starting at the second parameter
1458  * - As an array in the second parameter
1459  * These are not shown in the function definition.
1460  *
1461  * @return string
1462  */
1463 function wfMsg( $key ) {
1464         wfDeprecated( __METHOD__, '1.21' );
1465
1466         $args = func_get_args();
1467         array_shift( $args );
1468         return wfMsgReal( $key, $args );
1469 }
1470
1471 /**
1472  * Same as above except doesn't transform the message
1473  *
1474  * @deprecated since 1.18
1475  *
1476  * @param string $key
1477  * @return string
1478  */
1479 function wfMsgNoTrans( $key ) {
1480         wfDeprecated( __METHOD__, '1.21' );
1481
1482         $args = func_get_args();
1483         array_shift( $args );
1484         return wfMsgReal( $key, $args, true, false, false );
1485 }
1486
1487 /**
1488  * Get a message from anywhere, for the current global language
1489  * set with $wgLanguageCode.
1490  *
1491  * Use this if the message should NOT change dependent on the
1492  * language set in the user's preferences. This is the case for
1493  * most text written into logs, as well as link targets (such as
1494  * the name of the copyright policy page). Link titles, on the
1495  * other hand, should be shown in the UI language.
1496  *
1497  * Note that MediaWiki allows users to change the user interface
1498  * language in their preferences, but a single installation
1499  * typically only contains content in one language.
1500  *
1501  * Be wary of this distinction: If you use wfMsg() where you should
1502  * use wfMsgForContent(), a user of the software may have to
1503  * customize potentially hundreds of messages in
1504  * order to, e.g., fix a link in every possible language.
1505  *
1506  * @deprecated since 1.18
1507  *
1508  * @param string $key Lookup key for the message, usually
1509  *     defined in languages/Language.php
1510  * @return string
1511  */
1512 function wfMsgForContent( $key ) {
1513         wfDeprecated( __METHOD__, '1.21' );
1514
1515         global $wgForceUIMsgAsContentMsg;
1516         $args = func_get_args();
1517         array_shift( $args );
1518         $forcontent = true;
1519         if ( is_array( $wgForceUIMsgAsContentMsg )
1520                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1521         ) {
1522                 $forcontent = false;
1523         }
1524         return wfMsgReal( $key, $args, true, $forcontent );
1525 }
1526
1527 /**
1528  * Same as above except doesn't transform the message
1529  *
1530  * @deprecated since 1.18
1531  *
1532  * @param string $key
1533  * @return string
1534  */
1535 function wfMsgForContentNoTrans( $key ) {
1536         wfDeprecated( __METHOD__, '1.21' );
1537
1538         global $wgForceUIMsgAsContentMsg;
1539         $args = func_get_args();
1540         array_shift( $args );
1541         $forcontent = true;
1542         if ( is_array( $wgForceUIMsgAsContentMsg )
1543                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1544         ) {
1545                 $forcontent = false;
1546         }
1547         return wfMsgReal( $key, $args, true, $forcontent, false );
1548 }
1549
1550 /**
1551  * Really get a message
1552  *
1553  * @deprecated since 1.18
1554  *
1555  * @param string $key Key to get.
1556  * @param array $args
1557  * @param bool $useDB
1558  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1559  * @param bool $transform Whether or not to transform the message.
1560  * @return string The requested message.
1561  */
1562 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1563         wfDeprecated( __METHOD__, '1.21' );
1564
1565         wfProfileIn( __METHOD__ );
1566         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1567         $message = wfMsgReplaceArgs( $message, $args );
1568         wfProfileOut( __METHOD__ );
1569         return $message;
1570 }
1571
1572 /**
1573  * Fetch a message string value, but don't replace any keys yet.
1574  *
1575  * @deprecated since 1.18
1576  *
1577  * @param string $key
1578  * @param bool $useDB
1579  * @param string|bool $langCode Code of the language to get the message for, or
1580  *   behaves as a content language switch if it is a boolean.
1581  * @param bool $transform Whether to parse magic words, etc.
1582  * @return string
1583  */
1584 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1585         wfDeprecated( __METHOD__, '1.21' );
1586
1587         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1588
1589         $cache = MessageCache::singleton();
1590         $message = $cache->get( $key, $useDB, $langCode );
1591         if ( $message === false ) {
1592                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1593         } elseif ( $transform ) {
1594                 $message = $cache->transform( $message );
1595         }
1596         return $message;
1597 }
1598
1599 /**
1600  * Replace message parameter keys on the given formatted output.
1601  *
1602  * @param string $message
1603  * @param array $args
1604  * @return string
1605  * @private
1606  */
1607 function wfMsgReplaceArgs( $message, $args ) {
1608         # Fix windows line-endings
1609         # Some messages are split with explode("\n", $msg)
1610         $message = str_replace( "\r", '', $message );
1611
1612         // Replace arguments
1613         if ( count( $args ) ) {
1614                 if ( is_array( $args[0] ) ) {
1615                         $args = array_values( $args[0] );
1616                 }
1617                 $replacementKeys = array();
1618                 foreach ( $args as $n => $param ) {
1619                         $replacementKeys['$' . ( $n + 1 )] = $param;
1620                 }
1621                 $message = strtr( $message, $replacementKeys );
1622         }
1623
1624         return $message;
1625 }
1626
1627 /**
1628  * Return an HTML-escaped version of a message.
1629  * Parameter replacements, if any, are done *after* the HTML-escaping,
1630  * so parameters may contain HTML (eg links or form controls). Be sure
1631  * to pre-escape them if you really do want plaintext, or just wrap
1632  * the whole thing in htmlspecialchars().
1633  *
1634  * @deprecated since 1.18
1635  *
1636  * @param string $key
1637  * @param string $args,... Parameters
1638  * @return string
1639  */
1640 function wfMsgHtml( $key ) {
1641         wfDeprecated( __METHOD__, '1.21' );
1642
1643         $args = func_get_args();
1644         array_shift( $args );
1645         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1646 }
1647
1648 /**
1649  * Return an HTML version of message
1650  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1651  * so parameters may contain HTML (eg links or form controls). Be sure
1652  * to pre-escape them if you really do want plaintext, or just wrap
1653  * the whole thing in htmlspecialchars().
1654  *
1655  * @deprecated since 1.18
1656  *
1657  * @param string $key
1658  * @param string $args,... Parameters
1659  * @return string
1660  */
1661 function wfMsgWikiHtml( $key ) {
1662         wfDeprecated( __METHOD__, '1.21' );
1663
1664         $args = func_get_args();
1665         array_shift( $args );
1666         return wfMsgReplaceArgs(
1667                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1668                 /* can't be set to false */ true, /* interface */ true )->getText(),
1669                 $args );
1670 }
1671
1672 /**
1673  * Returns message in the requested format
1674  *
1675  * @deprecated since 1.18
1676  *
1677  * @param string $key Key of the message
1678  * @param array $options Processing rules.
1679  *   Can take the following options:
1680  *     parse: parses wikitext to HTML
1681  *     parseinline: parses wikitext to HTML and removes the surrounding
1682  *       p's added by parser or tidy
1683  *     escape: filters message through htmlspecialchars
1684  *     escapenoentities: same, but allows entity references like &#160; through
1685  *     replaceafter: parameters are substituted after parsing or escaping
1686  *     parsemag: transform the message using magic phrases
1687  *     content: fetch message for content language instead of interface
1688  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1689  *     language: Language object or language code to fetch message for
1690  *       (overridden by content).
1691  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1692  *
1693  * @return string
1694  */
1695 function wfMsgExt( $key, $options ) {
1696         wfDeprecated( __METHOD__, '1.21' );
1697
1698         $args = func_get_args();
1699         array_shift( $args );
1700         array_shift( $args );
1701         $options = (array)$options;
1702
1703         foreach ( $options as $arrayKey => $option ) {
1704                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1705                         # An unknown index, neither numeric nor "language"
1706                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1707                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1708                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1709                 'replaceafter', 'parsemag', 'content' ) ) ) {
1710                         # A numeric index with unknown value
1711                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1712                 }
1713         }
1714
1715         if ( in_array( 'content', $options, true ) ) {
1716                 $forContent = true;
1717                 $langCode = true;
1718                 $langCodeObj = null;
1719         } elseif ( array_key_exists( 'language', $options ) ) {
1720                 $forContent = false;
1721                 $langCode = wfGetLangObj( $options['language'] );
1722                 $langCodeObj = $langCode;
1723         } else {
1724                 $forContent = false;
1725                 $langCode = false;
1726                 $langCodeObj = null;
1727         }
1728
1729         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1730
1731         if ( !in_array( 'replaceafter', $options, true ) ) {
1732                 $string = wfMsgReplaceArgs( $string, $args );
1733         }
1734
1735         $messageCache = MessageCache::singleton();
1736         $parseInline = in_array( 'parseinline', $options, true );
1737         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1738                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1739                 if ( $string instanceof ParserOutput ) {
1740                         $string = $string->getText();
1741                 }
1742
1743                 if ( $parseInline ) {
1744                         $string = Parser::stripOuterParagraph( $string );
1745                 }
1746         } elseif ( in_array( 'parsemag', $options, true ) ) {
1747                 $string = $messageCache->transform( $string,
1748                                 !$forContent, $langCodeObj );
1749         }
1750
1751         if ( in_array( 'escape', $options, true ) ) {
1752                 $string = htmlspecialchars ( $string );
1753         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1754                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1755         }
1756
1757         if ( in_array( 'replaceafter', $options, true ) ) {
1758                 $string = wfMsgReplaceArgs( $string, $args );
1759         }
1760
1761         return $string;
1762 }
1763
1764 /**
1765  * Since wfMsg() and co suck, they don't return false if the message key they
1766  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1767  * nonexistence of messages by checking the MessageCache::get() result directly.
1768  *
1769  * @deprecated since 1.18. Use Message::isDisabled().
1770  *
1771  * @param string $key The message key looked up
1772  * @return bool True if the message *doesn't* exist.
1773  */
1774 function wfEmptyMsg( $key ) {
1775         wfDeprecated( __METHOD__, '1.21' );
1776
1777         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1778 }
1779
1780 /**
1781  * Fetch server name for use in error reporting etc.
1782  * Use real server name if available, so we know which machine
1783  * in a server farm generated the current page.
1784  *
1785  * @return string
1786  */
1787 function wfHostname() {
1788         static $host;
1789         if ( is_null( $host ) ) {
1790
1791                 # Hostname overriding
1792                 global $wgOverrideHostname;
1793                 if ( $wgOverrideHostname !== false ) {
1794                         # Set static and skip any detection
1795                         $host = $wgOverrideHostname;
1796                         return $host;
1797                 }
1798
1799                 if ( function_exists( 'posix_uname' ) ) {
1800                         // This function not present on Windows
1801                         $uname = posix_uname();
1802                 } else {
1803                         $uname = false;
1804                 }
1805                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1806                         $host = $uname['nodename'];
1807                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1808                         # Windows computer name
1809                         $host = getenv( 'COMPUTERNAME' );
1810                 } else {
1811                         # This may be a virtual server.
1812                         $host = $_SERVER['SERVER_NAME'];
1813                 }
1814         }
1815         return $host;
1816 }
1817
1818 /**
1819  * Returns a script tag that stores the amount of time it took MediaWiki to
1820  * handle the request in milliseconds as 'wgBackendResponseTime'.
1821  *
1822  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1823  * hostname of the server handling the request.
1824  *
1825  * @return string
1826  */
1827 function wfReportTime() {
1828         global $wgRequestTime, $wgShowHostnames;
1829
1830         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1831         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1832         if ( $wgShowHostnames ) {
1833                 $reportVars['wgHostname'] = wfHostname();
1834         }
1835         return Skin::makeVariablesScript( $reportVars );
1836 }
1837
1838 /**
1839  * Safety wrapper for debug_backtrace().
1840  *
1841  * Will return an empty array if debug_backtrace is disabled, otherwise
1842  * the output from debug_backtrace() (trimmed).
1843  *
1844  * @param int $limit This parameter can be used to limit the number of stack frames returned
1845  *
1846  * @return array Array of backtrace information
1847  */
1848 function wfDebugBacktrace( $limit = 0 ) {
1849         static $disabled = null;
1850
1851         if ( is_null( $disabled ) ) {
1852                 $disabled = !function_exists( 'debug_backtrace' );
1853                 if ( $disabled ) {
1854                         wfDebug( "debug_backtrace() is disabled\n" );
1855                 }
1856         }
1857         if ( $disabled ) {
1858                 return array();
1859         }
1860
1861         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1862                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1863         } else {
1864                 return array_slice( debug_backtrace(), 1 );
1865         }
1866 }
1867
1868 /**
1869  * Get a debug backtrace as a string
1870  *
1871  * @return string
1872  */
1873 function wfBacktrace() {
1874         global $wgCommandLineMode;
1875
1876         if ( $wgCommandLineMode ) {
1877                 $msg = '';
1878         } else {
1879                 $msg = "<ul>\n";
1880         }
1881         $backtrace = wfDebugBacktrace();
1882         foreach ( $backtrace as $call ) {
1883                 if ( isset( $call['file'] ) ) {
1884                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1885                         $file = $f[count( $f ) - 1];
1886                 } else {
1887                         $file = '-';
1888                 }
1889                 if ( isset( $call['line'] ) ) {
1890                         $line = $call['line'];
1891                 } else {
1892                         $line = '-';
1893                 }
1894                 if ( $wgCommandLineMode ) {
1895                         $msg .= "$file line $line calls ";
1896                 } else {
1897                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1898                 }
1899                 if ( !empty( $call['class'] ) ) {
1900                         $msg .= $call['class'] . $call['type'];
1901                 }
1902                 $msg .= $call['function'] . '()';
1903
1904                 if ( $wgCommandLineMode ) {
1905                         $msg .= "\n";
1906                 } else {
1907                         $msg .= "</li>\n";
1908                 }
1909         }
1910         if ( $wgCommandLineMode ) {
1911                 $msg .= "\n";
1912         } else {
1913                 $msg .= "</ul>\n";
1914         }
1915
1916         return $msg;
1917 }
1918
1919 /**
1920  * Get the name of the function which called this function
1921  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1922  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1923  * wfGetCaller( 3 ) is the parent of that.
1924  *
1925  * @param int $level
1926  * @return string
1927  */
1928 function wfGetCaller( $level = 2 ) {
1929         $backtrace = wfDebugBacktrace( $level + 1 );
1930         if ( isset( $backtrace[$level] ) ) {
1931                 return wfFormatStackFrame( $backtrace[$level] );
1932         } else {
1933                 return 'unknown';
1934         }
1935 }
1936
1937 /**
1938  * Return a string consisting of callers in the stack. Useful sometimes
1939  * for profiling specific points.
1940  *
1941  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1942  * @return string
1943  */
1944 function wfGetAllCallers( $limit = 3 ) {
1945         $trace = array_reverse( wfDebugBacktrace() );
1946         if ( !$limit || $limit > count( $trace ) - 1 ) {
1947                 $limit = count( $trace ) - 1;
1948         }
1949         $trace = array_slice( $trace, -$limit - 1, $limit );
1950         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1951 }
1952
1953 /**
1954  * Return a string representation of frame
1955  *
1956  * @param array $frame
1957  * @return string
1958  */
1959 function wfFormatStackFrame( $frame ) {
1960         return isset( $frame['class'] ) ?
1961                 $frame['class'] . '::' . $frame['function'] :
1962                 $frame['function'];
1963 }
1964
1965 /* Some generic result counters, pulled out of SearchEngine */
1966
1967 /**
1968  * @todo document
1969  *
1970  * @param int $offset
1971  * @param int $limit
1972  * @return string
1973  */
1974 function wfShowingResults( $offset, $limit ) {
1975         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1976 }
1977
1978 /**
1979  * @todo document
1980  * @todo FIXME: We may want to blacklist some broken browsers
1981  *
1982  * @param bool $force
1983  * @return bool Whereas client accept gzip compression
1984  */
1985 function wfClientAcceptsGzip( $force = false ) {
1986         static $result = null;
1987         if ( $result === null || $force ) {
1988                 $result = false;
1989                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1990                         # @todo FIXME: We may want to blacklist some broken browsers
1991                         $m = array();
1992                         if ( preg_match(
1993                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1994                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1995                                         $m
1996                                 )
1997                         ) {
1998                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1999                                         $result = false;
2000                                         return $result;
2001                                 }
2002                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2003                                 $result = true;
2004                         }
2005                 }
2006         }
2007         return $result;
2008 }
2009
2010 /**
2011  * Obtain the offset and limit values from the request string;
2012  * used in special pages
2013  *
2014  * @param int $deflimit Default limit if none supplied
2015  * @param string $optionname Name of a user preference to check against
2016  * @return array
2017  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2018  */
2019 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2020         global $wgRequest;
2021         wfDeprecated( __METHOD__, '1.24' );
2022         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2023 }
2024
2025 /**
2026  * Escapes the given text so that it may be output using addWikiText()
2027  * without any linking, formatting, etc. making its way through. This
2028  * is achieved by substituting certain characters with HTML entities.
2029  * As required by the callers, "<nowiki>" is not used.
2030  *
2031  * @param string $text Text to be escaped
2032  * @return string
2033  */
2034 function wfEscapeWikiText( $text ) {
2035         static $repl = null, $repl2 = null;
2036         if ( $repl === null ) {
2037                 $repl = array(
2038                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2039                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2040                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2041                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2042                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2043                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2044                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2045                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2046                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2047                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2048                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2049                         '__' => '_&#95;', '://' => '&#58;//',
2050                 );
2051
2052                 // We have to catch everything "\s" matches in PCRE
2053                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2054                         $repl["$magic "] = "$magic&#32;";
2055                         $repl["$magic\t"] = "$magic&#9;";
2056                         $repl["$magic\r"] = "$magic&#13;";
2057                         $repl["$magic\n"] = "$magic&#10;";
2058                         $repl["$magic\f"] = "$magic&#12;";
2059                 }
2060
2061                 // And handle protocols that don't use "://"
2062                 global $wgUrlProtocols;
2063                 $repl2 = array();
2064                 foreach ( $wgUrlProtocols as $prot ) {
2065                         if ( substr( $prot, -1 ) === ':' ) {
2066                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2067                         }
2068                 }
2069                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2070         }
2071         $text = substr( strtr( "\n$text", $repl ), 1 );
2072         $text = preg_replace( $repl2, '$1&#58;', $text );
2073         return $text;
2074 }
2075
2076 /**
2077  * Sets dest to source and returns the original value of dest
2078  * If source is NULL, it just returns the value, it doesn't set the variable
2079  * If force is true, it will set the value even if source is NULL
2080  *
2081  * @param mixed $dest
2082  * @param mixed $source
2083  * @param bool $force
2084  * @return mixed
2085  */
2086 function wfSetVar( &$dest, $source, $force = false ) {
2087         $temp = $dest;
2088         if ( !is_null( $source ) || $force ) {
2089                 $dest = $source;
2090         }
2091         return $temp;
2092 }
2093
2094 /**
2095  * As for wfSetVar except setting a bit
2096  *
2097  * @param int $dest
2098  * @param int $bit
2099  * @param bool $state
2100  *
2101  * @return bool
2102  */
2103 function wfSetBit( &$dest, $bit, $state = true ) {
2104         $temp = (bool)( $dest & $bit );
2105         if ( !is_null( $state ) ) {
2106                 if ( $state ) {
2107                         $dest |= $bit;
2108                 } else {
2109                         $dest &= ~$bit;
2110                 }
2111         }
2112         return $temp;
2113 }
2114
2115 /**
2116  * A wrapper around the PHP function var_export().
2117  * Either print it or add it to the regular output ($wgOut).
2118  *
2119  * @param mixed $var A PHP variable to dump.
2120  */
2121 function wfVarDump( $var ) {
2122         global $wgOut;
2123         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2124         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2125                 print $s;
2126         } else {
2127                 $wgOut->addHTML( $s );
2128         }
2129 }
2130
2131 /**
2132  * Provide a simple HTTP error.
2133  *
2134  * @param int|string $code
2135  * @param string $label
2136  * @param string $desc
2137  */
2138 function wfHttpError( $code, $label, $desc ) {
2139         global $wgOut;
2140         $wgOut->disable();
2141         header( "HTTP/1.0 $code $label" );
2142         header( "Status: $code $label" );
2143         $wgOut->sendCacheControl();
2144
2145         header( 'Content-type: text/html; charset=utf-8' );
2146         print "<!doctype html>" .
2147                 '<html><head><title>' .
2148                 htmlspecialchars( $label ) .
2149                 '</title></head><body><h1>' .
2150                 htmlspecialchars( $label ) .
2151                 '</h1><p>' .
2152                 nl2br( htmlspecialchars( $desc ) ) .
2153                 "</p></body></html>\n";
2154 }
2155
2156 /**
2157  * Clear away any user-level output buffers, discarding contents.
2158  *
2159  * Suitable for 'starting afresh', for instance when streaming
2160  * relatively large amounts of data without buffering, or wanting to
2161  * output image files without ob_gzhandler's compression.
2162  *
2163  * The optional $resetGzipEncoding parameter controls suppression of
2164  * the Content-Encoding header sent by ob_gzhandler; by default it
2165  * is left. See comments for wfClearOutputBuffers() for why it would
2166  * be used.
2167  *
2168  * Note that some PHP configuration options may add output buffer
2169  * layers which cannot be removed; these are left in place.
2170  *
2171  * @param bool $resetGzipEncoding
2172  */
2173 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2174         if ( $resetGzipEncoding ) {
2175                 // Suppress Content-Encoding and Content-Length
2176                 // headers from 1.10+s wfOutputHandler
2177                 global $wgDisableOutputCompression;
2178                 $wgDisableOutputCompression = true;
2179         }
2180         while ( $status = ob_get_status() ) {
2181                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2182                         // Probably from zlib.output_compression or other
2183                         // PHP-internal setting which can't be removed.
2184                         //
2185                         // Give up, and hope the result doesn't break
2186                         // output behavior.
2187                         break;
2188                 }
2189                 if ( !ob_end_clean() ) {
2190                         // Could not remove output buffer handler; abort now
2191                         // to avoid getting in some kind of infinite loop.
2192                         break;
2193                 }
2194                 if ( $resetGzipEncoding ) {
2195                         if ( $status['name'] == 'ob_gzhandler' ) {
2196                                 // Reset the 'Content-Encoding' field set by this handler
2197                                 // so we can start fresh.
2198                                 header_remove( 'Content-Encoding' );
2199                                 break;
2200                         }
2201                 }
2202         }
2203 }
2204
2205 /**
2206  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2207  *
2208  * Clear away output buffers, but keep the Content-Encoding header
2209  * produced by ob_gzhandler, if any.
2210  *
2211  * This should be used for HTTP 304 responses, where you need to
2212  * preserve the Content-Encoding header of the real result, but
2213  * also need to suppress the output of ob_gzhandler to keep to spec
2214  * and avoid breaking Firefox in rare cases where the headers and
2215  * body are broken over two packets.
2216  */
2217 function wfClearOutputBuffers() {
2218         wfResetOutputBuffers( false );
2219 }
2220
2221 /**
2222  * Converts an Accept-* header into an array mapping string values to quality
2223  * factors
2224  *
2225  * @param string $accept
2226  * @param string $def Default
2227  * @return float[] Associative array of string => float pairs
2228  */
2229 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2230         # No arg means accept anything (per HTTP spec)
2231         if ( !$accept ) {
2232                 return array( $def => 1.0 );
2233         }
2234
2235         $prefs = array();
2236
2237         $parts = explode( ',', $accept );
2238
2239         foreach ( $parts as $part ) {
2240                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2241                 $values = explode( ';', trim( $part ) );
2242                 $match = array();
2243                 if ( count( $values ) == 1 ) {
2244                         $prefs[$values[0]] = 1.0;
2245                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2246                         $prefs[$values[0]] = floatval( $match[1] );
2247                 }
2248         }
2249
2250         return $prefs;
2251 }
2252
2253 /**
2254  * Checks if a given MIME type matches any of the keys in the given
2255  * array. Basic wildcards are accepted in the array keys.
2256  *
2257  * Returns the matching MIME type (or wildcard) if a match, otherwise
2258  * NULL if no match.
2259  *
2260  * @param string $type
2261  * @param array $avail
2262  * @return string
2263  * @private
2264  */
2265 function mimeTypeMatch( $type, $avail ) {
2266         if ( array_key_exists( $type, $avail ) ) {
2267                 return $type;
2268         } else {
2269                 $parts = explode( '/', $type );
2270                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2271                         return $parts[0] . '/*';
2272                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2273                         return '*/*';
2274                 } else {
2275                         return null;
2276                 }
2277         }
2278 }
2279
2280 /**
2281  * Returns the 'best' match between a client's requested internet media types
2282  * and the server's list of available types. Each list should be an associative
2283  * array of type to preference (preference is a float between 0.0 and 1.0).
2284  * Wildcards in the types are acceptable.
2285  *
2286  * @param array $cprefs Client's acceptable type list
2287  * @param array $sprefs Server's offered types
2288  * @return string
2289  *
2290  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2291  * XXX: generalize to negotiate other stuff
2292  */
2293 function wfNegotiateType( $cprefs, $sprefs ) {
2294         $combine = array();
2295
2296         foreach ( array_keys( $sprefs ) as $type ) {
2297                 $parts = explode( '/', $type );
2298                 if ( $parts[1] != '*' ) {
2299                         $ckey = mimeTypeMatch( $type, $cprefs );
2300                         if ( $ckey ) {
2301                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2302                         }
2303                 }
2304         }
2305
2306         foreach ( array_keys( $cprefs ) as $type ) {
2307                 $parts = explode( '/', $type );
2308                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2309                         $skey = mimeTypeMatch( $type, $sprefs );
2310                         if ( $skey ) {
2311                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2312                         }
2313                 }
2314         }
2315
2316         $bestq = 0;
2317         $besttype = null;
2318
2319         foreach ( array_keys( $combine ) as $type ) {
2320                 if ( $combine[$type] > $bestq ) {
2321                         $besttype = $type;
2322                         $bestq = $combine[$type];
2323                 }
2324         }
2325
2326         return $besttype;
2327 }
2328
2329 /**
2330  * Reference-counted warning suppression
2331  *
2332  * @param bool $end
2333  */
2334 function wfSuppressWarnings( $end = false ) {
2335         static $suppressCount = 0;
2336         static $originalLevel = false;
2337
2338         if ( $end ) {
2339                 if ( $suppressCount ) {
2340                         --$suppressCount;
2341                         if ( !$suppressCount ) {
2342                                 error_reporting( $originalLevel );
2343                         }
2344                 }
2345         } else {
2346                 if ( !$suppressCount ) {
2347                         $originalLevel = error_reporting( E_ALL & ~(
2348                                 E_WARNING |
2349                                 E_NOTICE |
2350                                 E_USER_WARNING |
2351                                 E_USER_NOTICE |
2352                                 E_DEPRECATED |
2353                                 E_USER_DEPRECATED |
2354                                 E_STRICT
2355                         ) );
2356                 }
2357                 ++$suppressCount;
2358         }
2359 }
2360
2361 /**
2362  * Restore error level to previous value
2363  */
2364 function wfRestoreWarnings() {
2365         wfSuppressWarnings( true );
2366 }
2367
2368 # Autodetect, convert and provide timestamps of various types
2369
2370 /**
2371  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2372  */
2373 define( 'TS_UNIX', 0 );
2374
2375 /**
2376  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2377  */
2378 define( 'TS_MW', 1 );
2379
2380 /**
2381  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2382  */
2383 define( 'TS_DB', 2 );
2384
2385 /**
2386  * RFC 2822 format, for E-mail and HTTP headers
2387  */
2388 define( 'TS_RFC2822', 3 );
2389
2390 /**
2391  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2392  *
2393  * This is used by Special:Export
2394  */
2395 define( 'TS_ISO_8601', 4 );
2396
2397 /**
2398  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2399  *
2400  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2401  *       DateTime tag and page 36 for the DateTimeOriginal and
2402  *       DateTimeDigitized tags.
2403  */
2404 define( 'TS_EXIF', 5 );
2405
2406 /**
2407  * Oracle format time.
2408  */
2409 define( 'TS_ORACLE', 6 );
2410
2411 /**
2412  * Postgres format time.
2413  */
2414 define( 'TS_POSTGRES', 7 );
2415
2416 /**
2417  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2418  */
2419 define( 'TS_ISO_8601_BASIC', 9 );
2420
2421 /**
2422  * Get a timestamp string in one of various formats
2423  *
2424  * @param mixed $outputtype A timestamp in one of the supported formats, the
2425  *   function will autodetect which format is supplied and act accordingly.
2426  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2427  * @return string|bool String / false The same date in the format specified in $outputtype or false
2428  */
2429 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2430         try {
2431                 $timestamp = new MWTimestamp( $ts );
2432                 return $timestamp->getTimestamp( $outputtype );
2433         } catch ( TimestampException $e ) {
2434                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2435                 return false;
2436         }
2437 }
2438
2439 /**
2440  * Return a formatted timestamp, or null if input is null.
2441  * For dealing with nullable timestamp columns in the database.
2442  *
2443  * @param int $outputtype
2444  * @param string $ts
2445  * @return string
2446  */
2447 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2448         if ( is_null( $ts ) ) {
2449                 return null;
2450         } else {
2451                 return wfTimestamp( $outputtype, $ts );
2452         }
2453 }
2454
2455 /**
2456  * Convenience function; returns MediaWiki timestamp for the present time.
2457  *
2458  * @return string
2459  */
2460 function wfTimestampNow() {
2461         # return NOW
2462         return wfTimestamp( TS_MW, time() );
2463 }
2464
2465 /**
2466  * Check if the operating system is Windows
2467  *
2468  * @return bool True if it's Windows, false otherwise.
2469  */
2470 function wfIsWindows() {
2471         static $isWindows = null;
2472         if ( $isWindows === null ) {
2473                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2474         }
2475         return $isWindows;
2476 }
2477
2478 /**
2479  * Check if we are running under HHVM
2480  *
2481  * @return bool
2482  */
2483 function wfIsHHVM() {
2484         return defined( 'HHVM_VERSION' );
2485 }
2486
2487 /**
2488  * Swap two variables
2489  *
2490  * @deprecated since 1.24
2491  * @param mixed $x
2492  * @param mixed $y
2493  */
2494 function swap( &$x, &$y ) {
2495         wfDeprecated( __FUNCTION__, '1.24' );
2496         $z = $x;
2497         $x = $y;
2498         $y = $z;
2499 }
2500
2501 /**
2502  * Tries to get the system directory for temporary files. First
2503  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2504  * environment variables are then checked in sequence, and if none are
2505  * set try sys_get_temp_dir().
2506  *
2507  * NOTE: When possible, use instead the tmpfile() function to create
2508  * temporary files to avoid race conditions on file creation, etc.
2509  *
2510  * @return string
2511  */
2512 function wfTempDir() {
2513         global $wgTmpDirectory;
2514
2515         if ( $wgTmpDirectory !== false ) {
2516                 return $wgTmpDirectory;
2517         }
2518
2519         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2520
2521         foreach ( $tmpDir as $tmp ) {
2522                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2523                         return $tmp;
2524                 }
2525         }
2526         return sys_get_temp_dir();
2527 }
2528
2529 /**
2530  * Make directory, and make all parent directories if they don't exist
2531  *
2532  * @param string $dir Full path to directory to create
2533  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2534  * @param string $caller Optional caller param for debugging.
2535  * @throws MWException
2536  * @return bool
2537  */
2538 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2539         global $wgDirectoryMode;
2540
2541         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2542                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2543         }
2544
2545         if ( !is_null( $caller ) ) {
2546                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2547         }
2548
2549         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2550                 return true;
2551         }
2552
2553         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2554
2555         if ( is_null( $mode ) ) {
2556                 $mode = $wgDirectoryMode;
2557         }
2558
2559         // Turn off the normal warning, we're doing our own below
2560         wfSuppressWarnings();
2561         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2562         wfRestoreWarnings();
2563
2564         if ( !$ok ) {
2565                 //directory may have been created on another request since we last checked
2566                 if ( is_dir( $dir ) ) {
2567                         return true;
2568                 }
2569
2570                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2571                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2572         }
2573         return $ok;
2574 }
2575
2576 /**
2577  * Remove a directory and all its content.
2578  * Does not hide error.
2579  * @param string $dir
2580  */
2581 function wfRecursiveRemoveDir( $dir ) {
2582         wfDebug( __FUNCTION__ . "( $dir )\n" );
2583         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2584         if ( is_dir( $dir ) ) {
2585                 $objects = scandir( $dir );
2586                 foreach ( $objects as $object ) {
2587                         if ( $object != "." && $object != ".." ) {
2588                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2589                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2590                                 } else {
2591                                         unlink( $dir . '/' . $object );
2592                                 }
2593                         }
2594                 }
2595                 reset( $objects );
2596                 rmdir( $dir );
2597         }
2598 }
2599
2600 /**
2601  * @param int $nr The number to format
2602  * @param int $acc The number of digits after the decimal point, default 2
2603  * @param bool $round Whether or not to round the value, default true
2604  * @return string
2605  */
2606 function wfPercent( $nr, $acc = 2, $round = true ) {
2607         $ret = sprintf( "%.${acc}f", $nr );
2608         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2609 }
2610
2611 /**
2612  * Safety wrapper around ini_get() for boolean settings.
2613  * The values returned from ini_get() are pre-normalized for settings
2614  * set via php.ini or php_flag/php_admin_flag... but *not*
2615  * for those set via php_value/php_admin_value.
2616  *
2617  * It's fairly common for people to use php_value instead of php_flag,
2618  * which can leave you with an 'off' setting giving a false positive
2619  * for code that just takes the ini_get() return value as a boolean.
2620  *
2621  * To make things extra interesting, setting via php_value accepts
2622  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2623  * Unrecognized values go false... again opposite PHP's own coercion
2624  * from string to bool.
2625  *
2626  * Luckily, 'properly' set settings will always come back as '0' or '1',
2627  * so we only have to worry about them and the 'improper' settings.
2628  *
2629  * I frickin' hate PHP... :P
2630  *
2631  * @param string $setting
2632  * @return bool
2633  */
2634 function wfIniGetBool( $setting ) {
2635         $val = strtolower( ini_get( $setting ) );
2636         // 'on' and 'true' can't have whitespace around them, but '1' can.
2637         return $val == 'on'
2638                 || $val == 'true'
2639                 || $val == 'yes'
2640                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2641 }
2642
2643 /**
2644  * Windows-compatible version of escapeshellarg()
2645  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2646  * function puts single quotes in regardless of OS.
2647  *
2648  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2649  * earlier distro releases of PHP)
2650  *
2651  * @param string $args,...
2652  * @return string
2653  */
2654 function wfEscapeShellArg( /*...*/ ) {
2655         wfInitShellLocale();
2656
2657         $args = func_get_args();
2658         $first = true;
2659         $retVal = '';
2660         foreach ( $args as $arg ) {
2661                 if ( !$first ) {
2662                         $retVal .= ' ';
2663                 } else {
2664                         $first = false;
2665                 }
2666
2667                 if ( wfIsWindows() ) {
2668                         // Escaping for an MSVC-style command line parser and CMD.EXE
2669                         // @codingStandardsIgnoreStart For long URLs
2670                         // Refs:
2671                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2672                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2673                         //  * Bug #13518
2674                         //  * CR r63214
2675                         // Double the backslashes before any double quotes. Escape the double quotes.
2676                         // @codingStandardsIgnoreEnd
2677                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2678                         $arg = '';
2679                         $iteration = 0;
2680                         foreach ( $tokens as $token ) {
2681                                 if ( $iteration % 2 == 1 ) {
2682                                         // Delimiter, a double quote preceded by zero or more slashes
2683                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2684                                 } elseif ( $iteration % 4 == 2 ) {
2685                                         // ^ in $token will be outside quotes, need to be escaped
2686                                         $arg .= str_replace( '^', '^^', $token );
2687                                 } else { // $iteration % 4 == 0
2688                                         // ^ in $token will appear inside double quotes, so leave as is
2689                                         $arg .= $token;
2690                                 }
2691                                 $iteration++;
2692                         }
2693                         // Double the backslashes before the end of the string, because
2694                         // we will soon add a quote
2695                         $m = array();
2696                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2697                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2698                         }
2699
2700                         // Add surrounding quotes
2701                         $retVal .= '"' . $arg . '"';
2702                 } else {
2703                         $retVal .= escapeshellarg( $arg );
2704                 }
2705         }
2706         return $retVal;
2707 }
2708
2709 /**
2710  * Check if wfShellExec() is effectively disabled via php.ini config
2711  *
2712  * @return bool|string False or one of (safemode,disabled)
2713  * @since 1.22
2714  */
2715 function wfShellExecDisabled() {
2716         static $disabled = null;
2717         if ( is_null( $disabled ) ) {
2718                 if ( wfIniGetBool( 'safe_mode' ) ) {
2719                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2720                         $disabled = 'safemode';
2721                 } elseif ( !function_exists( 'proc_open' ) ) {
2722                         wfDebug( "proc_open() is disabled\n" );
2723                         $disabled = 'disabled';
2724                 } else {
2725                         $disabled = false;
2726                 }
2727         }
2728         return $disabled;
2729 }
2730
2731 /**
2732  * Execute a shell command, with time and memory limits mirrored from the PHP
2733  * configuration if supported.
2734  *
2735  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2736  *   or an array of unescaped arguments, in which case each value will be escaped
2737  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2738  * @param null|mixed &$retval Optional, will receive the program's exit code.
2739  *   (non-zero is usually failure). If there is an error from
2740  *   read, select, or proc_open(), this will be set to -1.
2741  * @param array $environ Optional environment variables which should be
2742  *   added to the executed command environment.
2743  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2744  *   this overwrites the global wgMaxShell* limits.
2745  * @param array $options Array of options:
2746  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2747  *     including errors from limit.sh
2748  *
2749  * @return string Collected stdout as a string
2750  */
2751 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2752         $limits = array(), $options = array()
2753 ) {
2754         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2755                 $wgMaxShellWallClockTime, $wgShellCgroup;
2756
2757         $disabled = wfShellExecDisabled();
2758         if ( $disabled ) {
2759                 $retval = 1;
2760                 return $disabled == 'safemode' ?
2761                         'Unable to run external programs in safe mode.' :
2762                         'Unable to run external programs, proc_open() is disabled.';
2763         }
2764
2765         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2766
2767         wfInitShellLocale();
2768
2769         $envcmd = '';
2770         foreach ( $environ as $k => $v ) {
2771                 if ( wfIsWindows() ) {
2772                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2773                          * appear in the environment variable, so we must use carat escaping as documented in
2774                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2775                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2776                          * are listed there but doesn't appear to need it.
2777                          */
2778                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2779                 } else {
2780                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2781                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2782                          */
2783                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2784                 }
2785         }
2786         if ( is_array( $cmd ) ) {
2787                 // Command line may be given as an array, escape each value and glue them together with a space
2788                 $cmdVals = array();
2789                 foreach ( $cmd as $val ) {
2790                         $cmdVals[] = wfEscapeShellArg( $val );
2791                 }
2792                 $cmd = implode( ' ', $cmdVals );
2793         }
2794
2795         $cmd = $envcmd . $cmd;
2796
2797         $useLogPipe = false;
2798         if ( is_executable( '/bin/bash' ) ) {
2799                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2800                 if ( isset( $limits['walltime'] ) ) {
2801                         $wallTime = intval( $limits['walltime'] );
2802                 } elseif ( isset( $limits['time'] ) ) {
2803                         $wallTime = $time;
2804                 } else {
2805                         $wallTime = intval( $wgMaxShellWallClockTime );
2806                 }
2807                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2808                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2809
2810                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2811                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2812                                 escapeshellarg( $cmd ) . ' ' .
2813                                 escapeshellarg(
2814                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2815                                         "MW_CPU_LIMIT=$time; " .
2816                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2817                                         "MW_MEM_LIMIT=$mem; " .
2818                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2819                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2820                                         "MW_USE_LOG_PIPE=yes"
2821                                 );
2822                         $useLogPipe = true;
2823                 } elseif ( $includeStderr ) {
2824                         $cmd .= ' 2>&1';
2825                 }
2826         } elseif ( $includeStderr ) {
2827                 $cmd .= ' 2>&1';
2828         }
2829         wfDebug( "wfShellExec: $cmd\n" );
2830
2831         $desc = array(
2832                 0 => array( 'file', 'php://stdin', 'r' ),
2833                 1 => array( 'pipe', 'w' ),
2834                 2 => array( 'file', 'php://stderr', 'w' ) );
2835         if ( $useLogPipe ) {
2836                 $desc[3] = array( 'pipe', 'w' );
2837         }
2838         $pipes = null;
2839         $proc = proc_open( $cmd, $desc, $pipes );
2840         if ( !$proc ) {
2841                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2842                 $retval = -1;
2843                 return '';
2844         }
2845         $outBuffer = $logBuffer = '';
2846         $emptyArray = array();
2847         $status = false;
2848         $logMsg = false;
2849
2850         // According to the documentation, it is possible for stream_select()
2851         // to fail due to EINTR. I haven't managed to induce this in testing
2852         // despite sending various signals. If it did happen, the error
2853         // message would take the form:
2854         //
2855         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2856         //
2857         // where [4] is the value of the macro EINTR and "Interrupted system
2858         // call" is string which according to the Linux manual is "possibly"
2859         // localised according to LC_MESSAGES.
2860         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2861         $eintrMessage = "stream_select(): unable to select [$eintr]";
2862
2863         // Build a table mapping resource IDs to pipe FDs to work around a
2864         // PHP 5.3 issue in which stream_select() does not preserve array keys
2865         // <https://bugs.php.net/bug.php?id=53427>.
2866         $fds = array();
2867         foreach ( $pipes as $fd => $pipe ) {
2868                 $fds[(int)$pipe] = $fd;
2869         }
2870
2871         $running = true;
2872         $timeout = null;
2873         $numReadyPipes = 0;
2874
2875         while ( $running === true || $numReadyPipes !== 0 ) {
2876                 if ( $running ) {
2877                         $status = proc_get_status( $proc );
2878                         // If the process has terminated, switch to nonblocking selects
2879                         // for getting any data still waiting to be read.
2880                         if ( !$status['running'] ) {
2881                                 $running = false;
2882                                 $timeout = 0;
2883                         }
2884                 }
2885
2886                 $readyPipes = $pipes;
2887
2888                 // Clear last error
2889                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2890                 @trigger_error( '' );
2891                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2892                 if ( $numReadyPipes === false ) {
2893                         // @codingStandardsIgnoreEnd
2894                         $error = error_get_last();
2895                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2896                                 continue;
2897                         } else {
2898                                 trigger_error( $error['message'], E_USER_WARNING );
2899                                 $logMsg = $error['message'];
2900                                 break;
2901                         }
2902                 }
2903                 foreach ( $readyPipes as $pipe ) {
2904                         $block = fread( $pipe, 65536 );
2905                         $fd = $fds[(int)$pipe];
2906                         if ( $block === '' ) {
2907                                 // End of file
2908                                 fclose( $pipes[$fd] );
2909                                 unset( $pipes[$fd] );
2910                                 if ( !$pipes ) {
2911                                         break 2;
2912                                 }
2913                         } elseif ( $block === false ) {
2914                                 // Read error
2915                                 $logMsg = "Error reading from pipe";
2916                                 break 2;
2917                         } elseif ( $fd == 1 ) {
2918                                 // From stdout
2919                                 $outBuffer .= $block;
2920                         } elseif ( $fd == 3 ) {
2921                                 // From log FD
2922                                 $logBuffer .= $block;
2923                                 if ( strpos( $block, "\n" ) !== false ) {
2924                                         $lines = explode( "\n", $logBuffer );
2925                                         $logBuffer = array_pop( $lines );
2926                                         foreach ( $lines as $line ) {
2927                                                 wfDebugLog( 'exec', $line );
2928                                         }
2929                                 }
2930                         }
2931                 }
2932         }
2933
2934         foreach ( $pipes as $pipe ) {
2935                 fclose( $pipe );
2936         }
2937
2938         // Use the status previously collected if possible, since proc_get_status()
2939         // just calls waitpid() which will not return anything useful the second time.
2940         if ( $running ) {
2941                 $status = proc_get_status( $proc );
2942         }
2943
2944         if ( $logMsg !== false ) {
2945                 // Read/select error
2946                 $retval = -1;
2947                 proc_close( $proc );
2948         } elseif ( $status['signaled'] ) {
2949                 $logMsg = "Exited with signal {$status['termsig']}";
2950                 $retval = 128 + $status['termsig'];
2951                 proc_close( $proc );
2952         } else {
2953                 if ( $status['running'] ) {
2954                         $retval = proc_close( $proc );
2955                 } else {
2956                         $retval = $status['exitcode'];
2957                         proc_close( $proc );
2958                 }
2959                 if ( $retval == 127 ) {
2960                         $logMsg = "Possibly missing executable file";
2961                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2962                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2963                 }
2964         }
2965
2966         if ( $logMsg !== false ) {
2967                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2968         }
2969
2970         return $outBuffer;
2971 }
2972
2973 /**
2974  * Execute a shell command, returning both stdout and stderr. Convenience
2975  * function, as all the arguments to wfShellExec can become unwieldy.
2976  *
2977  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2978  * @param string $cmd Command line, properly escaped for shell.
2979  * @param null|mixed &$retval Optional, will receive the program's exit code.
2980  *   (non-zero is usually failure)
2981  * @param array $environ Optional environment variables which should be
2982  *   added to the executed command environment.
2983  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2984  *   this overwrites the global wgMaxShell* limits.
2985  * @return string Collected stdout and stderr as a string
2986  */
2987 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2988         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2989 }
2990
2991 /**
2992  * Workaround for http://bugs.php.net/bug.php?id=45132
2993  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2994  */
2995 function wfInitShellLocale() {
2996         static $done = false;
2997         if ( $done ) {
2998                 return;
2999         }
3000         $done = true;
3001         global $wgShellLocale;
3002         if ( !wfIniGetBool( 'safe_mode' ) ) {
3003                 putenv( "LC_CTYPE=$wgShellLocale" );
3004                 setlocale( LC_CTYPE, $wgShellLocale );
3005         }
3006 }
3007
3008 /**
3009  * Alias to wfShellWikiCmd()
3010  *
3011  * @see wfShellWikiCmd()
3012  */
3013 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3014         return wfShellWikiCmd( $script, $parameters, $options );
3015 }
3016
3017 /**
3018  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3019  * Note that $parameters should be a flat array and an option with an argument
3020  * should consist of two consecutive items in the array (do not use "--option value").
3021  *
3022  * @param string $script MediaWiki cli script path
3023  * @param array $parameters Arguments and options to the script
3024  * @param array $options Associative array of options:
3025  *              'php': The path to the php executable
3026  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3027  * @return string
3028  */
3029 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3030         global $wgPhpCli;
3031         // Give site config file a chance to run the script in a wrapper.
3032         // The caller may likely want to call wfBasename() on $script.
3033         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3034         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3035         if ( isset( $options['wrapper'] ) ) {
3036                 $cmd[] = $options['wrapper'];
3037         }
3038         $cmd[] = $script;
3039         // Escape each parameter for shell
3040         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3041 }
3042
3043 /**
3044  * wfMerge attempts to merge differences between three texts.
3045  * Returns true for a clean merge and false for failure or a conflict.
3046  *
3047  * @param string $old
3048  * @param string $mine
3049  * @param string $yours
3050  * @param string $result
3051  * @return bool
3052  */
3053 function wfMerge( $old, $mine, $yours, &$result ) {
3054         global $wgDiff3;
3055
3056         # This check may also protect against code injection in
3057         # case of broken installations.
3058         wfSuppressWarnings();
3059         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3060         wfRestoreWarnings();
3061
3062         if ( !$haveDiff3 ) {
3063                 wfDebug( "diff3 not found\n" );
3064                 return false;
3065         }
3066
3067         # Make temporary files
3068         $td = wfTempDir();
3069         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3070         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3071         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3072
3073         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3074         #       a newline character. To avoid this, we normalize the trailing whitespace before
3075         #       creating the diff.
3076
3077         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3078         fclose( $oldtextFile );
3079         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3080         fclose( $mytextFile );
3081         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3082         fclose( $yourtextFile );
3083
3084         # Check for a conflict
3085         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3086                 wfEscapeShellArg( $mytextName ) . ' ' .
3087                 wfEscapeShellArg( $oldtextName ) . ' ' .
3088                 wfEscapeShellArg( $yourtextName );
3089         $handle = popen( $cmd, 'r' );
3090
3091         if ( fgets( $handle, 1024 ) ) {
3092                 $conflict = true;
3093         } else {
3094                 $conflict = false;
3095         }
3096         pclose( $handle );
3097
3098         # Merge differences
3099         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3100                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3101         $handle = popen( $cmd, 'r' );
3102         $result = '';
3103         do {
3104                 $data = fread( $handle, 8192 );
3105                 if ( strlen( $data ) == 0 ) {
3106                         break;
3107                 }
3108                 $result .= $data;
3109         } while ( true );
3110         pclose( $handle );
3111         unlink( $mytextName );
3112         unlink( $oldtextName );
3113         unlink( $yourtextName );
3114
3115         if ( $result === '' && $old !== '' && !$conflict ) {
3116                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3117                 $conflict = true;
3118         }
3119         return !$conflict;
3120 }
3121
3122 /**
3123  * Returns unified plain-text diff of two texts.
3124  * Useful for machine processing of diffs.
3125  *
3126  * @param string $before The text before the changes.
3127  * @param string $after The text after the changes.
3128  * @param string $params Command-line options for the diff command.
3129  * @return string Unified diff of $before and $after
3130  */
3131 function wfDiff( $before, $after, $params = '-u' ) {
3132         if ( $before == $after ) {
3133                 return '';
3134         }
3135
3136         global $wgDiff;
3137         wfSuppressWarnings();
3138         $haveDiff = $wgDiff && file_exists( $wgDiff );
3139         wfRestoreWarnings();
3140
3141         # This check may also protect against code injection in
3142         # case of broken installations.
3143         if ( !$haveDiff ) {
3144                 wfDebug( "diff executable not found\n" );
3145                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3146                 $format = new UnifiedDiffFormatter();
3147                 return $format->format( $diffs );
3148         }
3149
3150         # Make temporary files
3151         $td = wfTempDir();
3152         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3153         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3154
3155         fwrite( $oldtextFile, $before );
3156         fclose( $oldtextFile );
3157         fwrite( $newtextFile, $after );
3158         fclose( $newtextFile );
3159
3160         // Get the diff of the two files
3161         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3162
3163         $h = popen( $cmd, 'r' );
3164
3165         $diff = '';
3166
3167         do {
3168                 $data = fread( $h, 8192 );
3169                 if ( strlen( $data ) == 0 ) {
3170                         break;
3171                 }
3172                 $diff .= $data;
3173         } while ( true );
3174
3175         // Clean up
3176         pclose( $h );
3177         unlink( $oldtextName );
3178         unlink( $newtextName );
3179
3180         // Kill the --- and +++ lines. They're not useful.
3181         $diff_lines = explode( "\n", $diff );
3182         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3183                 unset( $diff_lines[0] );
3184         }
3185         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3186                 unset( $diff_lines[1] );
3187         }
3188
3189         $diff = implode( "\n", $diff_lines );
3190
3191         return $diff;
3192 }
3193
3194 /**
3195  * This function works like "use VERSION" in Perl, the program will die with a
3196  * backtrace if the current version of PHP is less than the version provided
3197  *
3198  * This is useful for extensions which due to their nature are not kept in sync
3199  * with releases, and might depend on other versions of PHP than the main code
3200  *
3201  * Note: PHP might die due to parsing errors in some cases before it ever
3202  *       manages to call this function, such is life
3203  *
3204  * @see perldoc -f use
3205  *
3206  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3207  * @throws MWException
3208  */
3209 function wfUsePHP( $req_ver ) {
3210         $php_ver = PHP_VERSION;
3211
3212         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3213                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3214         }
3215 }
3216
3217 /**
3218  * This function works like "use VERSION" in Perl except it checks the version
3219  * of MediaWiki, the program will die with a backtrace if the current version
3220  * of MediaWiki is less than the version provided.
3221  *
3222  * This is useful for extensions which due to their nature are not kept in sync
3223  * with releases
3224  *
3225  * Note: Due to the behavior of PHP's version_compare() which is used in this
3226  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3227  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3228  * targeted version number. For example if you wanted to allow any variation
3229  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3230  * not result in the same comparison due to the internal logic of
3231  * version_compare().
3232  *
3233  * @see perldoc -f use
3234  *
3235  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3236  * @throws MWException
3237  */
3238 function wfUseMW( $req_ver ) {
3239         global $wgVersion;
3240
3241         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3242                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3243         }
3244 }
3245
3246 /**
3247  * Return the final portion of a pathname.
3248  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3249  * http://bugs.php.net/bug.php?id=33898
3250  *
3251  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3252  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3253  *
3254  * @param string $path
3255  * @param string $suffix String to remove if present
3256  * @return string
3257  */
3258 function wfBaseName( $path, $suffix = '' ) {
3259         if ( $suffix == '' ) {
3260                 $encSuffix = '';
3261         } else {
3262                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3263         }
3264
3265         $matches = array();
3266         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3267                 return $matches[1];
3268         } else {
3269                 return '';
3270         }
3271 }
3272
3273 /**
3274  * Generate a relative path name to the given file.
3275  * May explode on non-matching case-insensitive paths,
3276  * funky symlinks, etc.
3277  *
3278  * @param string $path Absolute destination path including target filename
3279  * @param string $from Absolute source path, directory only
3280  * @return string
3281  */
3282 function wfRelativePath( $path, $from ) {
3283         // Normalize mixed input on Windows...
3284         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3285         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3286
3287         // Trim trailing slashes -- fix for drive root
3288         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3289         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3290
3291         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3292         $against = explode( DIRECTORY_SEPARATOR, $from );
3293
3294         if ( $pieces[0] !== $against[0] ) {
3295                 // Non-matching Windows drive letters?
3296                 // Return a full path.
3297                 return $path;
3298         }
3299
3300         // Trim off common prefix
3301         while ( count( $pieces ) && count( $against )
3302                 && $pieces[0] == $against[0] ) {
3303                 array_shift( $pieces );
3304                 array_shift( $against );
3305         }
3306
3307         // relative dots to bump us to the parent
3308         while ( count( $against ) ) {
3309                 array_unshift( $pieces, '..' );
3310                 array_shift( $against );
3311         }
3312
3313         array_push( $pieces, wfBaseName( $path ) );
3314
3315         return implode( DIRECTORY_SEPARATOR, $pieces );
3316 }
3317
3318 /**
3319  * Convert an arbitrarily-long digit string from one numeric base
3320  * to another, optionally zero-padding to a minimum column width.
3321  *
3322  * Supports base 2 through 36; digit values 10-36 are represented
3323  * as lowercase letters a-z. Input is case-insensitive.
3324  *
3325  * @param string $input Input number
3326  * @param int $sourceBase Base of the input number
3327  * @param int $destBase Desired base of the output
3328  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3329  * @param bool $lowercase Whether to output in lowercase or uppercase
3330  * @param string $engine Either "gmp", "bcmath", or "php"
3331  * @return string|bool The output number as a string, or false on error
3332  */
3333 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3334         $lowercase = true, $engine = 'auto'
3335 ) {
3336         $input = (string)$input;
3337         if (
3338                 $sourceBase < 2 ||
3339                 $sourceBase > 36 ||
3340                 $destBase < 2 ||
3341                 $destBase > 36 ||
3342                 $sourceBase != (int)$sourceBase ||
3343                 $destBase != (int)$destBase ||
3344                 $pad != (int)$pad ||
3345                 !preg_match(
3346                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3347                         $input
3348                 )
3349         ) {
3350                 return false;
3351         }
3352
3353         static $baseChars = array(
3354                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3355                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3356                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3357                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3358                 34 => 'y', 35 => 'z',
3359
3360                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3361                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3362                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3363                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3364                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3365                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3366         );
3367
3368         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3369                 // Removing leading zeros works around broken base detection code in
3370                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3371                 // <https://bugs.php.net/bug.php?id=55398>).
3372                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3373         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3374                 $decimal = '0';
3375                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3376                         $decimal = bcmul( $decimal, $sourceBase );
3377                         $decimal = bcadd( $decimal, $baseChars[$char] );
3378                 }
3379
3380                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3381                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3382                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3383                 }
3384                 // @codingStandardsIgnoreEnd
3385
3386                 $result = strrev( $result );
3387         } else {
3388                 $inDigits = array();
3389                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3390                         $inDigits[] = $baseChars[$char];
3391                 }
3392
3393                 // Iterate over the input, modulo-ing out an output digit
3394                 // at a time until input is gone.
3395                 $result = '';
3396                 while ( $inDigits ) {
3397                         $work = 0;
3398                         $workDigits = array();
3399
3400                         // Long division...
3401                         foreach ( $inDigits as $digit ) {
3402                                 $work *= $sourceBase;
3403                                 $work += $digit;
3404
3405                                 if ( $workDigits || $work >= $destBase ) {
3406                                         $workDigits[] = (int)( $work / $destBase );
3407                                 }
3408                                 $work %= $destBase;
3409                         }
3410
3411                         // All that division leaves us with a remainder,
3412                         // which is conveniently our next output digit.
3413                         $result .= $baseChars[$work];
3414
3415                         // And we continue!
3416                         $inDigits = $workDigits;
3417                 }
3418
3419                 $result = strrev( $result );
3420         }
3421
3422         if ( !$lowercase ) {
3423                 $result = strtoupper( $result );
3424         }
3425
3426         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3427 }
3428
3429 /**
3430  * Check if there is sufficient entropy in php's built-in session generation
3431  *
3432  * @return bool True = there is sufficient entropy
3433  */
3434 function wfCheckEntropy() {
3435         return (
3436                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3437                         || ini_get( 'session.entropy_file' )
3438                 )
3439                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3440 }
3441
3442 /**
3443  * Override session_id before session startup if php's built-in
3444  * session generation code is not secure.
3445  */
3446 function wfFixSessionID() {
3447         // If the cookie or session id is already set we already have a session and should abort
3448         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3449                 return;
3450         }
3451
3452         // PHP's built-in session entropy is enabled if:
3453         // - entropy_file is set or you're on Windows with php 5.3.3+
3454         // - AND entropy_length is > 0
3455         // We treat it as disabled if it doesn't have an entropy length of at least 32
3456         $entropyEnabled = wfCheckEntropy();
3457
3458         // If built-in entropy is not enabled or not sufficient override PHP's
3459         // built in session id generation code
3460         if ( !$entropyEnabled ) {
3461                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3462                         "overriding session id generation using our cryptrand source.\n" );
3463                 session_id( MWCryptRand::generateHex( 32 ) );
3464         }
3465 }
3466
3467 /**
3468  * Reset the session_id
3469  *
3470  * @since 1.22
3471  */
3472 function wfResetSessionID() {
3473         global $wgCookieSecure;
3474         $oldSessionId = session_id();
3475         $cookieParams = session_get_cookie_params();
3476         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3477                 session_regenerate_id( false );
3478         } else {
3479                 $tmp = $_SESSION;
3480                 session_destroy();
3481                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3482                 $_SESSION = $tmp;
3483         }
3484         $newSessionId = session_id();
3485         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3486 }
3487
3488 /**
3489  * Initialise php session
3490  *
3491  * @param bool $sessionId
3492  */
3493 function wfSetupSession( $sessionId = false ) {
3494         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3495                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3496         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3497                 ObjectCacheSessionHandler::install();
3498         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3499                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3500                 # hasn't already been set to the desired value (that causes errors)
3501                 ini_set( 'session.save_handler', $wgSessionHandler );
3502         }
3503         session_set_cookie_params(
3504                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3505         session_cache_limiter( 'private, must-revalidate' );
3506         if ( $sessionId ) {
3507                 session_id( $sessionId );
3508         } else {
3509                 wfFixSessionID();
3510         }
3511         wfSuppressWarnings();
3512         session_start();
3513         wfRestoreWarnings();
3514 }
3515
3516 /**
3517  * Get an object from the precompiled serialized directory
3518  *
3519  * @param string $name
3520  * @return mixed The variable on success, false on failure
3521  */
3522 function wfGetPrecompiledData( $name ) {
3523         global $IP;
3524
3525         $file = "$IP/serialized/$name";
3526         if ( file_exists( $file ) ) {
3527                 $blob = file_get_contents( $file );
3528                 if ( $blob ) {
3529                         return unserialize( $blob );
3530                 }
3531         }
3532         return false;
3533 }
3534
3535 /**
3536  * Get a cache key
3537  *
3538  * @param string $args,...
3539  * @return string
3540  */
3541 function wfMemcKey( /*...*/ ) {
3542         global $wgCachePrefix;
3543         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3544         $args = func_get_args();
3545         $key = $prefix . ':' . implode( ':', $args );
3546         $key = str_replace( ' ', '_', $key );
3547         return $key;
3548 }
3549
3550 /**
3551  * Get a cache key for a foreign DB
3552  *
3553  * @param string $db
3554  * @param string $prefix
3555  * @param string $args,...
3556  * @return string
3557  */
3558 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3559         $args = array_slice( func_get_args(), 2 );
3560         if ( $prefix ) {
3561                 $key = "$db-$prefix:" . implode( ':', $args );
3562         } else {
3563                 $key = $db . ':' . implode( ':', $args );
3564         }
3565         return str_replace( ' ', '_', $key );
3566 }
3567
3568 /**
3569  * Get an ASCII string identifying this wiki
3570  * This is used as a prefix in memcached keys
3571  *
3572  * @return string
3573  */
3574 function wfWikiID() {
3575         global $wgDBprefix, $wgDBname;
3576         if ( $wgDBprefix ) {
3577                 return "$wgDBname-$wgDBprefix";
3578         } else {
3579                 return $wgDBname;
3580         }
3581 }
3582
3583 /**
3584  * Split a wiki ID into DB name and table prefix
3585  *
3586  * @param string $wiki
3587  *
3588  * @return array
3589  */
3590 function wfSplitWikiID( $wiki ) {
3591         $bits = explode( '-', $wiki, 2 );
3592         if ( count( $bits ) < 2 ) {
3593                 $bits[] = '';
3594         }
3595         return $bits;
3596 }
3597
3598 /**
3599  * Get a Database object.
3600  *
3601  * @param int $db Index of the connection to get. May be DB_MASTER for the
3602  *            master (for write queries), DB_SLAVE for potentially lagged read
3603  *            queries, or an integer >= 0 for a particular server.
3604  *
3605  * @param string|string[] $groups Query groups. An array of group names that this query
3606  *                belongs to. May contain a single string if the query is only
3607  *                in one group.
3608  *
3609  * @param string|bool $wiki The wiki ID, or false for the current wiki
3610  *
3611  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3612  * will always return the same object, unless the underlying connection or load
3613  * balancer is manually destroyed.
3614  *
3615  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3616  * updater to ensure that a proper database is being updated.
3617  *
3618  * @return DatabaseBase
3619  */
3620 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3621         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3622 }
3623
3624 /**
3625  * Get a load balancer object.
3626  *
3627  * @param string|bool $wiki Wiki ID, or false for the current wiki
3628  * @return LoadBalancer
3629  */
3630 function wfGetLB( $wiki = false ) {
3631         return wfGetLBFactory()->getMainLB( $wiki );
3632 }
3633
3634 /**
3635  * Get the load balancer factory object
3636  *
3637  * @return LBFactory
3638  */
3639 function &wfGetLBFactory() {
3640         return LBFactory::singleton();
3641 }
3642
3643 /**
3644  * Find a file.
3645  * Shortcut for RepoGroup::singleton()->findFile()
3646  *
3647  * @param string $title String or Title object
3648  * @param array $options Associative array of options:
3649  *     time:           requested time for an archived image, or false for the
3650  *                     current version. An image object will be returned which was
3651  *                     created at the specified time.
3652  *
3653  *     ignoreRedirect: If true, do not follow file redirects
3654  *
3655  *     private:        If true, return restricted (deleted) files if the current
3656  *                     user is allowed to view them. Otherwise, such files will not
3657  *                     be found.
3658  *
3659  *     bypassCache:    If true, do not use the process-local cache of File objects
3660  *
3661  * @return File|bool File, or false if the file does not exist
3662  */
3663 function wfFindFile( $title, $options = array() ) {
3664         return RepoGroup::singleton()->findFile( $title, $options );
3665 }
3666
3667 /**
3668  * Get an object referring to a locally registered file.
3669  * Returns a valid placeholder object if the file does not exist.
3670  *
3671  * @param Title|string $title
3672  * @return LocalFile|null A File, or null if passed an invalid Title
3673  */
3674 function wfLocalFile( $title ) {
3675         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3676 }
3677
3678 /**
3679  * Should low-performance queries be disabled?
3680  *
3681  * @return bool
3682  * @codeCoverageIgnore
3683  */
3684 function wfQueriesMustScale() {
3685         global $wgMiserMode;
3686         return $wgMiserMode
3687                 || ( SiteStats::pages() > 100000
3688                 && SiteStats::edits() > 1000000
3689                 && SiteStats::users() > 10000 );
3690 }
3691
3692 /**
3693  * Get the path to a specified script file, respecting file
3694  * extensions; this is a wrapper around $wgScriptExtension etc.
3695  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3696  *
3697  * @param string $script Script filename, sans extension
3698  * @return string
3699  */
3700 function wfScript( $script = 'index' ) {
3701         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3702         if ( $script === 'index' ) {
3703                 return $wgScript;
3704         } elseif ( $script === 'load' ) {
3705                 return $wgLoadScript;
3706         } else {
3707                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3708         }
3709 }
3710
3711 /**
3712  * Get the script URL.
3713  *
3714  * @return string Script URL
3715  */
3716 function wfGetScriptUrl() {
3717         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3718                 #
3719                 # as it was called, minus the query string.
3720                 #
3721                 # Some sites use Apache rewrite rules to handle subdomains,
3722                 # and have PHP set up in a weird way that causes PHP_SELF
3723                 # to contain the rewritten URL instead of the one that the
3724                 # outside world sees.
3725                 #
3726                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3727                 # provides containing the "before" URL.
3728                 return $_SERVER['SCRIPT_NAME'];
3729         } else {
3730                 return $_SERVER['URL'];
3731         }
3732 }
3733
3734 /**
3735  * Convenience function converts boolean values into "true"
3736  * or "false" (string) values
3737  *
3738  * @param bool $value
3739  * @return string
3740  */
3741 function wfBoolToStr( $value ) {
3742         return $value ? 'true' : 'false';
3743 }
3744
3745 /**
3746  * Get a platform-independent path to the null file, e.g. /dev/null
3747  *
3748  * @return string
3749  */
3750 function wfGetNull() {
3751         return wfIsWindows() ? 'NUL' : '/dev/null';
3752 }
3753
3754 /**
3755  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3756  * and waiting for it to go down, this waits for the slaves to catch up to the
3757  * master position. Use this when updating very large numbers of rows, as
3758  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3759  * a no-op if there are no slaves.
3760  *
3761  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3762  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3763  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3764  * @return bool Success (able to connect and no timeouts reached)
3765  */
3766 function wfWaitForSlaves( $ifWritesSince = false, $wiki = false, $cluster = false ) {
3767         // B/C: first argument used to be "max seconds of lag"; ignore such values
3768         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : false;
3769
3770         if ( $cluster !== false ) {
3771                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3772         } else {
3773                 $lb = wfGetLB( $wiki );
3774         }
3775
3776         // bug 27975 - Don't try to wait for slaves if there are none
3777         // Prevents permission error when getting master position
3778         if ( $lb->getServerCount() > 1 ) {
3779                 if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3780                         return true; // assume no writes done
3781                 }
3782                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3783                 if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3784                         return true; // no writes since the last wait
3785                 }
3786                 $pos = $dbw->getMasterPos();
3787                 // The DBMS may not support getMasterPos() or the whole
3788                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3789                 if ( $pos !== false ) {
3790                         return $lb->waitForAll( $pos, PHP_SAPI === 'cli' ? 86400 : null );
3791                 }
3792         }
3793
3794         return true;
3795 }
3796
3797 /**
3798  * Count down from $seconds to zero on the terminal, with a one-second pause
3799  * between showing each number. For use in command-line scripts.
3800  *
3801  * @codeCoverageIgnore
3802  * @param int $seconds
3803  */
3804 function wfCountDown( $seconds ) {
3805         for ( $i = $seconds; $i >= 0; $i-- ) {
3806                 if ( $i != $seconds ) {
3807                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3808                 }
3809                 echo $i;
3810                 flush();
3811                 if ( $i ) {
3812                         sleep( 1 );
3813                 }
3814         }
3815         echo "\n";
3816 }
3817
3818 /**
3819  * Replace all invalid characters with -
3820  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3821  * By default, $wgIllegalFileChars = ':'
3822  *
3823  * @param string $name Filename to process
3824  * @return string
3825  */
3826 function wfStripIllegalFilenameChars( $name ) {
3827         global $wgIllegalFileChars;
3828         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3829         $name = wfBaseName( $name );
3830         $name = preg_replace(
3831                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3832                 '-',
3833                 $name
3834         );
3835         return $name;
3836 }
3837
3838 /**
3839  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3840  *
3841  * @return int Value the memory limit was set to.
3842  */
3843 function wfMemoryLimit() {
3844         global $wgMemoryLimit;
3845         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3846         if ( $memlimit != -1 ) {
3847                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3848                 if ( $conflimit == -1 ) {
3849                         wfDebug( "Removing PHP's memory limit\n" );
3850                         wfSuppressWarnings();
3851                         ini_set( 'memory_limit', $conflimit );
3852                         wfRestoreWarnings();
3853                         return $conflimit;
3854                 } elseif ( $conflimit > $memlimit ) {
3855                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3856                         wfSuppressWarnings();
3857                         ini_set( 'memory_limit', $conflimit );
3858                         wfRestoreWarnings();
3859                         return $conflimit;
3860                 }
3861         }
3862         return $memlimit;
3863 }
3864
3865 /**
3866  * Converts shorthand byte notation to integer form
3867  *
3868  * @param string $string
3869  * @return int
3870  */
3871 function wfShorthandToInteger( $string = '' ) {
3872         $string = trim( $string );
3873         if ( $string === '' ) {
3874                 return -1;
3875         }
3876         $last = $string[strlen( $string ) - 1];
3877         $val = intval( $string );
3878         switch ( $last ) {
3879                 case 'g':
3880                 case 'G':
3881                         $val *= 1024;
3882                         // break intentionally missing
3883                 case 'm':
3884                 case 'M':
3885                         $val *= 1024;
3886                         // break intentionally missing
3887                 case 'k':
3888                 case 'K':
3889                         $val *= 1024;
3890         }
3891
3892         return $val;
3893 }
3894
3895 /**
3896  * Get the normalised IETF language tag
3897  * See unit test for examples.
3898  *
3899  * @param string $code The language code.
3900  * @return string The language code which complying with BCP 47 standards.
3901  */
3902 function wfBCP47( $code ) {
3903         $codeSegment = explode( '-', $code );
3904         $codeBCP = array();
3905         foreach ( $codeSegment as $segNo => $seg ) {
3906                 // when previous segment is x, it is a private segment and should be lc
3907                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3908                         $codeBCP[$segNo] = strtolower( $seg );
3909                 // ISO 3166 country code
3910                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3911                         $codeBCP[$segNo] = strtoupper( $seg );
3912                 // ISO 15924 script code
3913                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3914                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3915                 // Use lowercase for other cases
3916                 } else {
3917                         $codeBCP[$segNo] = strtolower( $seg );
3918                 }
3919         }
3920         $langCode = implode( '-', $codeBCP );
3921         return $langCode;
3922 }
3923
3924 /**
3925  * Get a cache object.
3926  *
3927  * @param int $inputType Cache type, one the the CACHE_* constants.
3928  * @return BagOStuff
3929  */
3930 function wfGetCache( $inputType ) {
3931         return ObjectCache::getInstance( $inputType );
3932 }
3933
3934 /**
3935  * Get the main cache object
3936  *
3937  * @return BagOStuff
3938  */
3939 function wfGetMainCache() {
3940         global $wgMainCacheType;
3941         return ObjectCache::getInstance( $wgMainCacheType );
3942 }
3943
3944 /**
3945  * Get the cache object used by the message cache
3946  *
3947  * @return BagOStuff
3948  */
3949 function wfGetMessageCacheStorage() {
3950         global $wgMessageCacheType;
3951         return ObjectCache::getInstance( $wgMessageCacheType );
3952 }
3953
3954 /**
3955  * Get the cache object used by the parser cache
3956  *
3957  * @return BagOStuff
3958  */
3959 function wfGetParserCacheStorage() {
3960         global $wgParserCacheType;
3961         return ObjectCache::getInstance( $wgParserCacheType );
3962 }
3963
3964 /**
3965  * Get the cache object used by the language converter
3966  *
3967  * @return BagOStuff
3968  */
3969 function wfGetLangConverterCacheStorage() {
3970         global $wgLanguageConverterCacheType;
3971         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3972 }
3973
3974 /**
3975  * Call hook functions defined in $wgHooks
3976  *
3977  * @param string $event Event name
3978  * @param array $args Parameters passed to hook functions
3979  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3980  *
3981  * @return bool True if no handler aborted the hook
3982  */
3983 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3984         return Hooks::run( $event, $args, $deprecatedVersion );
3985 }
3986
3987 /**
3988  * Wrapper around php's unpack.
3989  *
3990  * @param string $format The format string (See php's docs)
3991  * @param string $data A binary string of binary data
3992  * @param int|bool $length The minimum length of $data or false. This is to
3993  *      prevent reading beyond the end of $data. false to disable the check.
3994  *
3995  * Also be careful when using this function to read unsigned 32 bit integer
3996  * because php might make it negative.
3997  *
3998  * @throws MWException If $data not long enough, or if unpack fails
3999  * @return array Associative array of the extracted data
4000  */
4001 function wfUnpack( $format, $data, $length = false ) {
4002         if ( $length !== false ) {
4003                 $realLen = strlen( $data );
4004                 if ( $realLen < $length ) {
4005                         throw new MWException( "Tried to use wfUnpack on a "
4006                                 . "string of length $realLen, but needed one "
4007                                 . "of at least length $length."
4008                         );
4009                 }
4010         }
4011
4012         wfSuppressWarnings();
4013         $result = unpack( $format, $data );
4014         wfRestoreWarnings();
4015
4016         if ( $result === false ) {
4017                 // If it cannot extract the packed data.
4018                 throw new MWException( "unpack could not unpack binary data" );
4019         }
4020         return $result;
4021 }
4022
4023 /**
4024  * Determine if an image exists on the 'bad image list'.
4025  *
4026  * The format of MediaWiki:Bad_image_list is as follows:
4027  *    * Only list items (lines starting with "*") are considered
4028  *    * The first link on a line must be a link to a bad image
4029  *    * Any subsequent links on the same line are considered to be exceptions,
4030  *      i.e. articles where the image may occur inline.
4031  *
4032  * @param string $name The image name to check
4033  * @param Title|bool $contextTitle The page on which the image occurs, if known
4034  * @param string $blacklist Wikitext of a file blacklist
4035  * @return bool
4036  */
4037 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4038         static $badImageCache = null; // based on bad_image_list msg
4039         wfProfileIn( __METHOD__ );
4040
4041         # Handle redirects
4042         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4043         if ( $redirectTitle ) {
4044                 $name = $redirectTitle->getDBkey();
4045         }
4046
4047         # Run the extension hook
4048         $bad = false;
4049         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4050                 wfProfileOut( __METHOD__ );
4051                 return $bad;
4052         }
4053
4054         $cacheable = ( $blacklist === null );
4055         if ( $cacheable && $badImageCache !== null ) {
4056                 $badImages = $badImageCache;
4057         } else { // cache miss
4058                 if ( $blacklist === null ) {
4059                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4060                 }
4061                 # Build the list now
4062                 $badImages = array();
4063                 $lines = explode( "\n", $blacklist );
4064                 foreach ( $lines as $line ) {
4065                         # List items only
4066                         if ( substr( $line, 0, 1 ) !== '*' ) {
4067                                 continue;
4068                         }
4069
4070                         # Find all links
4071                         $m = array();
4072                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4073                                 continue;
4074                         }
4075
4076                         $exceptions = array();
4077                         $imageDBkey = false;
4078                         foreach ( $m[1] as $i => $titleText ) {
4079                                 $title = Title::newFromText( $titleText );
4080                                 if ( !is_null( $title ) ) {
4081                                         if ( $i == 0 ) {
4082                                                 $imageDBkey = $title->getDBkey();
4083                                         } else {
4084                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4085                                         }
4086                                 }
4087                         }
4088
4089                         if ( $imageDBkey !== false ) {
4090                                 $badImages[$imageDBkey] = $exceptions;
4091                         }
4092                 }
4093                 if ( $cacheable ) {
4094                         $badImageCache = $badImages;
4095                 }
4096         }
4097
4098         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4099         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4100         wfProfileOut( __METHOD__ );
4101         return $bad;
4102 }
4103
4104 /**
4105  * Determine whether the client at a given source IP is likely to be able to
4106  * access the wiki via HTTPS.
4107  *
4108  * @param string $ip The IPv4/6 address in the normal human-readable form
4109  * @return bool
4110  */
4111 function wfCanIPUseHTTPS( $ip ) {
4112         $canDo = true;
4113         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4114         return !!$canDo;
4115 }
4116
4117 /**
4118  * Work out the IP address based on various globals
4119  * For trusted proxies, use the XFF client IP (first of the chain)
4120  *
4121  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4122  * @return string
4123  */
4124 function wfGetIP() {
4125         wfDeprecated( __METHOD__, '1.19' );
4126         global $wgRequest;
4127         return $wgRequest->getIP();
4128 }
4129
4130 /**
4131  * Checks if an IP is a trusted proxy provider.
4132  * Useful to tell if X-Forwarded-For data is possibly bogus.
4133  * Squid cache servers for the site are whitelisted.
4134  * @deprecated Since 1.24, use IP::isTrustedProxy()
4135  *
4136  * @param string $ip
4137  * @return bool
4138  */
4139 function wfIsTrustedProxy( $ip ) {
4140         return IP::isTrustedProxy( $ip );
4141 }
4142
4143 /**
4144  * Checks if an IP matches a proxy we've configured.
4145  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4146  *
4147  * @param string $ip
4148  * @return bool
4149  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4150  */
4151 function wfIsConfiguredProxy( $ip ) {
4152         return IP::isConfiguredProxy( $ip );
4153 }