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 use Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\Session\SessionManager;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.5.9 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 // hash_equals function only exists in PHP >= 5.6.0
  43 // http://php.net/hash_equals
  44 if ( !function_exists( 'hash_equals' ) ) {
  45         /**
  46          * Check whether a user-provided string is equal to a fixed-length secret string
  47          * without revealing bytes of the secret string through timing differences.
  48          *
  49          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
  50          * function in C) is to compare corresponding bytes and stop at the first difference,
  51          * which would take longer for a partial match than for a complete mismatch. This
  52          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
  53          * and the other may come from an attacker. Statistical analysis of timing measurements
  54          * over many requests may allow the attacker to guess the string's bytes one at a time
  55          * (and check his guesses) even if the timing differences are extremely small.
  56          *
  57          * When making such a security-sensitive comparison, it is essential that the sequence
  58          * in which instructions are executed and memory locations are accessed not depend on
  59          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
  60          * the inevitable leakage of the string's length. That is generally known anyway as
  61          * a chararacteristic of the hash function used to compute the secret value.
  62          *
  63          * Longer explanation: http://www.emerose.com/timing-attacks-explained
  64          *
  65          * @codeCoverageIgnore
  66          * @param string $known_string Fixed-length secret string to compare against
  67          * @param string $user_string User-provided string
  68          * @return bool True if the strings are the same, false otherwise
  69          */
  70         function hash_equals( $known_string, $user_string ) {
  71                 // Strict type checking as in PHP's native implementation
  72                 if ( !is_string( $known_string ) ) {
  73                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
  74                                 gettype( $known_string ) . ' given', E_USER_WARNING );
  75
  76                         return false;
  77                 }
  78
  79                 if ( !is_string( $user_string ) ) {
  80                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
  81                                 gettype( $user_string ) . ' given', E_USER_WARNING );
  82
  83                         return false;
  84                 }
  85
  86                 $known_string_len = strlen( $known_string );
  87                 if ( $known_string_len !== strlen( $user_string ) ) {
  88                         return false;
  89                 }
  90
  91                 $result = 0;
  92                 for ( $i = 0; $i < $known_string_len; $i++ ) {
  93                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
  94                 }
  95
  96                 return ( $result === 0 );
  97         }
  98 }
  99 /// @endcond
 100
 101 /**
 102  * Load an extension
 103  *
 104  * This queues an extension to be loaded through
 105  * the ExtensionRegistry system.
 106  *
 107  * @param string $ext Name of the extension to load
 108  * @param string|null $path Absolute path of where to find the extension.json file
 109  * @since 1.25
 110  */
 111 function wfLoadExtension( $ext, $path = null ) {
 112         if ( !$path ) {
 113                 global $wgExtensionDirectory;
 114                 $path = "$wgExtensionDirectory/$ext/extension.json";
 115         }
 116         ExtensionRegistry::getInstance()->queue( $path );
 117 }
 118
 119 /**
 120  * Load multiple extensions at once
 121  *
 122  * Same as wfLoadExtension, but more efficient if you
 123  * are loading multiple extensions.
 124  *
 125  * If you want to specify custom paths, you should interact with
 126  * ExtensionRegistry directly.
 127  *
 128  * @see wfLoadExtension
 129  * @param string[] $exts Array of extension names to load
 130  * @since 1.25
 131  */
 132 function wfLoadExtensions( array $exts ) {
 133         global $wgExtensionDirectory;
 134         $registry = ExtensionRegistry::getInstance();
 135         foreach ( $exts as $ext ) {
 136                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 137         }
 138 }
 139
 140 /**
 141  * Load a skin
 142  *
 143  * @see wfLoadExtension
 144  * @param string $skin Name of the extension to load
 145  * @param string|null $path Absolute path of where to find the skin.json file
 146  * @since 1.25
 147  */
 148 function wfLoadSkin( $skin, $path = null ) {
 149         if ( !$path ) {
 150                 global $wgStyleDirectory;
 151                 $path = "$wgStyleDirectory/$skin/skin.json";
 152         }
 153         ExtensionRegistry::getInstance()->queue( $path );
 154 }
 155
 156 /**
 157  * Load multiple skins at once
 158  *
 159  * @see wfLoadExtensions
 160  * @param string[] $skins Array of extension names to load
 161  * @since 1.25
 162  */
 163 function wfLoadSkins( array $skins ) {
 164         global $wgStyleDirectory;
 165         $registry = ExtensionRegistry::getInstance();
 166         foreach ( $skins as $skin ) {
 167                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 168         }
 169 }
 170
 171 /**
 172  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 173  * @param array $a
 174  * @param array $b
 175  * @return array
 176  */
 177 function wfArrayDiff2( $a, $b ) {
 178         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 179 }
 180
 181 /**
 182  * @param array|string $a
 183  * @param array|string $b
 184  * @return int
 185  */
 186 function wfArrayDiff2_cmp( $a, $b ) {
 187         if ( is_string( $a ) && is_string( $b ) ) {
 188                 return strcmp( $a, $b );
 189         } elseif ( count( $a ) !== count( $b ) ) {
 190                 return count( $a ) < count( $b ) ? -1 : 1;
 191         } else {
 192                 reset( $a );
 193                 reset( $b );
 194                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 195                         $cmp = strcmp( $valueA, $valueB );
 196                         if ( $cmp !== 0 ) {
 197                                 return $cmp;
 198                         }
 199                 }
 200                 return 0;
 201         }
 202 }
 203
 204 /**
 205  * Appends to second array if $value differs from that in $default
 206  *
 207  * @param string|int $key
 208  * @param mixed $value
 209  * @param mixed $default
 210  * @param array $changed Array to alter
 211  * @throws MWException
 212  */
 213 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 214         if ( is_null( $changed ) ) {
 215                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 216         }
 217         if ( $default[$key] !== $value ) {
 218                 $changed[$key] = $value;
 219         }
 220 }
 221
 222 /**
 223  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 224  * e.g.
 225  *      wfMergeErrorArrays(
 226  *              array( array( 'x' ) ),
 227  *              array( array( 'x', '2' ) ),
 228  *              array( array( 'x' ) ),
 229  *              array( array( 'y' ) )
 230  *      );
 231  * returns:
 232  *              array(
 233  *              array( 'x', '2' ),
 234  *              array( 'x' ),
 235  *              array( 'y' )
 236  *      )
 237  *
 238  * @param array $array1,...
 239  * @return array
 240  */
 241 function wfMergeErrorArrays( /*...*/ ) {
 242         $args = func_get_args();
 243         $out = [];
 244         foreach ( $args as $errors ) {
 245                 foreach ( $errors as $params ) {
 246                         $originalParams = $params;
 247                         if ( $params[0] instanceof MessageSpecifier ) {
 248                                 $msg = $params[0];
 249                                 $params = array_merge( [ $msg->getKey() ], $msg->getParams() );
 250                         }
 251                         # @todo FIXME: Sometimes get nested arrays for $params,
 252                         # which leads to E_NOTICEs
 253                         $spec = implode( "\t", $params );
 254                         $out[$spec] = $originalParams;
 255                 }
 256         }
 257         return array_values( $out );
 258 }
 259
 260 /**
 261  * Insert array into another array after the specified *KEY*
 262  *
 263  * @param array $array The array.
 264  * @param array $insert The array to insert.
 265  * @param mixed $after The key to insert after
 266  * @return array
 267  */
 268 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 269         // Find the offset of the element to insert after.
 270         $keys = array_keys( $array );
 271         $offsetByKey = array_flip( $keys );
 272
 273         $offset = $offsetByKey[$after];
 274
 275         // Insert at the specified offset
 276         $before = array_slice( $array, 0, $offset + 1, true );
 277         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 278
 279         $output = $before + $insert + $after;
 280
 281         return $output;
 282 }
 283
 284 /**
 285  * Recursively converts the parameter (an object) to an array with the same data
 286  *
 287  * @param object|array $objOrArray
 288  * @param bool $recursive
 289  * @return array
 290  */
 291 function wfObjectToArray( $objOrArray, $recursive = true ) {
 292         $array = [];
 293         if ( is_object( $objOrArray ) ) {
 294                 $objOrArray = get_object_vars( $objOrArray );
 295         }
 296         foreach ( $objOrArray as $key => $value ) {
 297                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 298                         $value = wfObjectToArray( $value );
 299                 }
 300
 301                 $array[$key] = $value;
 302         }
 303
 304         return $array;
 305 }
 306
 307 /**
 308  * Get a random decimal value between 0 and 1, in a way
 309  * not likely to give duplicate values for any realistic
 310  * number of articles.
 311  *
 312  * @note This is designed for use in relation to Special:RandomPage
 313  *       and the page_random database field.
 314  *
 315  * @return string
 316  */
 317 function wfRandom() {
 318         // The maximum random value is "only" 2^31-1, so get two random
 319         // values to reduce the chance of dupes
 320         $max = mt_getrandmax() + 1;
 321         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 322         return $rand;
 323 }
 324
 325 /**
 326  * Get a random string containing a number of pseudo-random hex characters.
 327  *
 328  * @note This is not secure, if you are trying to generate some sort
 329  *       of token please use MWCryptRand instead.
 330  *
 331  * @param int $length The length of the string to generate
 332  * @return string
 333  * @since 1.20
 334  */
 335 function wfRandomString( $length = 32 ) {
 336         $str = '';
 337         for ( $n = 0; $n < $length; $n += 7 ) {
 338                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 339         }
 340         return substr( $str, 0, $length );
 341 }
 342
 343 /**
 344  * We want some things to be included as literal characters in our title URLs
 345  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 346  * all of the following should be safe:
 347  *
 348  * ;:@&=$-_.+!*'(),
 349  *
 350  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 351  * character which should not be encoded. More importantly, google chrome
 352  * always converts %7E back to ~, and converting it in this function can
 353  * cause a redirect loop (T105265).
 354  *
 355  * But + is not safe because it's used to indicate a space; &= are only safe in
 356  * paths and not in queries (and we don't distinguish here); ' seems kind of
 357  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 358  * is reserved, we don't care.  So the list we unescape is:
 359  *
 360  * ;:@$!*(),/~
 361  *
 362  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 363  * so no fancy : for IIS7.
 364  *
 365  * %2F in the page titles seems to fatally break for some reason.
 366  *
 367  * @param string $s
 368  * @return string
 369  */
 370 function wfUrlencode( $s ) {
 371         static $needle;
 372
 373         if ( is_null( $s ) ) {
 374                 $needle = null;
 375                 return '';
 376         }
 377
 378         if ( is_null( $needle ) ) {
 379                 $needle = [ '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' ];
 380                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 381                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 382                 ) {
 383                         $needle[] = '%3A';
 384                 }
 385         }
 386
 387         $s = urlencode( $s );
 388         $s = str_ireplace(
 389                 $needle,
 390                 [ ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ],
 391                 $s
 392         );
 393
 394         return $s;
 395 }
 396
 397 /**
 398  * This function takes one or two arrays as input, and returns a CGI-style string, e.g.
 399  * "days=7&limit=100". Options in the first array override options in the second.
 400  * Options set to null or false will not be output.
 401  *
 402  * @param array $array1 ( String|Array )
 403  * @param array|null $array2 ( String|Array )
 404  * @param string $prefix
 405  * @return string
 406  */
 407 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 408         if ( !is_null( $array2 ) ) {
 409                 $array1 = $array1 + $array2;
 410         }
 411
 412         $cgi = '';
 413         foreach ( $array1 as $key => $value ) {
 414                 if ( !is_null( $value ) && $value !== false ) {
 415                         if ( $cgi != '' ) {
 416                                 $cgi .= '&';
 417                         }
 418                         if ( $prefix !== '' ) {
 419                                 $key = $prefix . "[$key]";
 420                         }
 421                         if ( is_array( $value ) ) {
 422                                 $firstTime = true;
 423                                 foreach ( $value as $k => $v ) {
 424                                         $cgi .= $firstTime ? '' : '&';
 425                                         if ( is_array( $v ) ) {
 426                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 427                                         } else {
 428                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 429                                         }
 430                                         $firstTime = false;
 431                                 }
 432                         } else {
 433                                 if ( is_object( $value ) ) {
 434                                         $value = $value->__toString();
 435                                 }
 436                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 437                         }
 438                 }
 439         }
 440         return $cgi;
 441 }
 442
 443 /**
 444  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 445  * its argument and returns the same string in array form.  This allows compatibility
 446  * with legacy functions that accept raw query strings instead of nice
 447  * arrays.  Of course, keys and values are urldecode()d.
 448  *
 449  * @param string $query Query string
 450  * @return string[] Array version of input
 451  */
 452 function wfCgiToArray( $query ) {
 453         if ( isset( $query[0] ) && $query[0] == '?' ) {
 454                 $query = substr( $query, 1 );
 455         }
 456         $bits = explode( '&', $query );
 457         $ret = [];
 458         foreach ( $bits as $bit ) {
 459                 if ( $bit === '' ) {
 460                         continue;
 461                 }
 462                 if ( strpos( $bit, '=' ) === false ) {
 463                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 464                         $key = $bit;
 465                         $value = '';
 466                 } else {
 467                         list( $key, $value ) = explode( '=', $bit );
 468                 }
 469                 $key = urldecode( $key );
 470                 $value = urldecode( $value );
 471                 if ( strpos( $key, '[' ) !== false ) {
 472                         $keys = array_reverse( explode( '[', $key ) );
 473                         $key = array_pop( $keys );
 474                         $temp = $value;
 475                         foreach ( $keys as $k ) {
 476                                 $k = substr( $k, 0, -1 );
 477                                 $temp = [ $k => $temp ];
 478                         }
 479                         if ( isset( $ret[$key] ) ) {
 480                                 $ret[$key] = array_merge( $ret[$key], $temp );
 481                         } else {
 482                                 $ret[$key] = $temp;
 483                         }
 484                 } else {
 485                         $ret[$key] = $value;
 486                 }
 487         }
 488         return $ret;
 489 }
 490
 491 /**
 492  * Append a query string to an existing URL, which may or may not already
 493  * have query string parameters already. If so, they will be combined.
 494  *
 495  * @param string $url
 496  * @param string|string[] $query String or associative array
 497  * @return string
 498  */
 499 function wfAppendQuery( $url, $query ) {
 500         if ( is_array( $query ) ) {
 501                 $query = wfArrayToCgi( $query );
 502         }
 503         if ( $query != '' ) {
 504                 if ( false === strpos( $url, '?' ) ) {
 505                         $url .= '?';
 506                 } else {
 507                         $url .= '&';
 508                 }
 509                 $url .= $query;
 510         }
 511         return $url;
 512 }
 513
 514 /**
 515  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 516  * is correct.
 517  *
 518  * The meaning of the PROTO_* constants is as follows:
 519  * PROTO_HTTP: Output a URL starting with http://
 520  * PROTO_HTTPS: Output a URL starting with https://
 521  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 522  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 523  *    on which protocol was used for the current incoming request
 524  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 525  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 526  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 527  *
 528  * @todo this won't work with current-path-relative URLs
 529  * like "subdir/foo.html", etc.
 530  *
 531  * @param string $url Either fully-qualified or a local path + query
 532  * @param string $defaultProto One of the PROTO_* constants. Determines the
 533  *    protocol to use if $url or $wgServer is protocol-relative
 534  * @return string Fully-qualified URL, current-path-relative URL or false if
 535  *    no valid URL can be constructed
 536  */
 537 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 538         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 539                 $wgHttpsPort;
 540         if ( $defaultProto === PROTO_CANONICAL ) {
 541                 $serverUrl = $wgCanonicalServer;
 542         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 543                 // Make $wgInternalServer fall back to $wgServer if not set
 544                 $serverUrl = $wgInternalServer;
 545         } else {
 546                 $serverUrl = $wgServer;
 547                 if ( $defaultProto === PROTO_CURRENT ) {
 548                         $defaultProto = $wgRequest->getProtocol() . '://';
 549                 }
 550         }
 551
 552         // Analyze $serverUrl to obtain its protocol
 553         $bits = wfParseUrl( $serverUrl );
 554         $serverHasProto = $bits && $bits['scheme'] != '';
 555
 556         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 557                 if ( $serverHasProto ) {
 558                         $defaultProto = $bits['scheme'] . '://';
 559                 } else {
 560                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 561                         // This really isn't supposed to happen. Fall back to HTTP in this
 562                         // ridiculous case.
 563                         $defaultProto = PROTO_HTTP;
 564                 }
 565         }
 566
 567         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 568
 569         if ( substr( $url, 0, 2 ) == '//' ) {
 570                 $url = $defaultProtoWithoutSlashes . $url;
 571         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 572                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 573                 // otherwise leave it alone.
 574                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 575         }
 576
 577         $bits = wfParseUrl( $url );
 578
 579         // ensure proper port for HTTPS arrives in URL
 580         // https://phabricator.wikimedia.org/T67184
 581         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 582                 $bits['port'] = $wgHttpsPort;
 583         }
 584
 585         if ( $bits && isset( $bits['path'] ) ) {
 586                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 587                 return wfAssembleUrl( $bits );
 588         } elseif ( $bits ) {
 589                 # No path to expand
 590                 return $url;
 591         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 592                 # URL is a relative path
 593                 return wfRemoveDotSegments( $url );
 594         }
 595
 596         # Expanded URL is not valid.
 597         return false;
 598 }
 599
 600 /**
 601  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 602  * if you need to edit part of a URL and put it back together.
 603  *
 604  * This is the basic structure used (brackets contain keys for $urlParts):
 605  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 606  *
 607  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 608  *
 609  * @since 1.19
 610  * @param array $urlParts URL parts, as output from wfParseUrl
 611  * @return string URL assembled from its component parts
 612  */
 613 function wfAssembleUrl( $urlParts ) {
 614         $result = '';
 615
 616         if ( isset( $urlParts['delimiter'] ) ) {
 617                 if ( isset( $urlParts['scheme'] ) ) {
 618                         $result .= $urlParts['scheme'];
 619                 }
 620
 621                 $result .= $urlParts['delimiter'];
 622         }
 623
 624         if ( isset( $urlParts['host'] ) ) {
 625                 if ( isset( $urlParts['user'] ) ) {
 626                         $result .= $urlParts['user'];
 627                         if ( isset( $urlParts['pass'] ) ) {
 628                                 $result .= ':' . $urlParts['pass'];
 629                         }
 630                         $result .= '@';
 631                 }
 632
 633                 $result .= $urlParts['host'];
 634
 635                 if ( isset( $urlParts['port'] ) ) {
 636                         $result .= ':' . $urlParts['port'];
 637                 }
 638         }
 639
 640         if ( isset( $urlParts['path'] ) ) {
 641                 $result .= $urlParts['path'];
 642         }
 643
 644         if ( isset( $urlParts['query'] ) ) {
 645                 $result .= '?' . $urlParts['query'];
 646         }
 647
 648         if ( isset( $urlParts['fragment'] ) ) {
 649                 $result .= '#' . $urlParts['fragment'];
 650         }
 651
 652         return $result;
 653 }
 654
 655 /**
 656  * Remove all dot-segments in the provided URL path.  For example,
 657  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 658  * RFC3986 section 5.2.4.
 659  *
 660  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 661  *
 662  * @param string $urlPath URL path, potentially containing dot-segments
 663  * @return string URL path with all dot-segments removed
 664  */
 665 function wfRemoveDotSegments( $urlPath ) {
 666         $output = '';
 667         $inputOffset = 0;
 668         $inputLength = strlen( $urlPath );
 669
 670         while ( $inputOffset < $inputLength ) {
 671                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 672                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 673                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 674                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 675                 $trimOutput = false;
 676
 677                 if ( $prefixLengthTwo == './' ) {
 678                         # Step A, remove leading "./"
 679                         $inputOffset += 2;
 680                 } elseif ( $prefixLengthThree == '../' ) {
 681                         # Step A, remove leading "../"
 682                         $inputOffset += 3;
 683                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 684                         # Step B, replace leading "/.$" with "/"
 685                         $inputOffset += 1;
 686                         $urlPath[$inputOffset] = '/';
 687                 } elseif ( $prefixLengthThree == '/./' ) {
 688                         # Step B, replace leading "/./" with "/"
 689                         $inputOffset += 2;
 690                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 691                         # Step C, replace leading "/..$" with "/" and
 692                         # remove last path component in output
 693                         $inputOffset += 2;
 694                         $urlPath[$inputOffset] = '/';
 695                         $trimOutput = true;
 696                 } elseif ( $prefixLengthFour == '/../' ) {
 697                         # Step C, replace leading "/../" with "/" and
 698                         # remove last path component in output
 699                         $inputOffset += 3;
 700                         $trimOutput = true;
 701                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 702                         # Step D, remove "^.$"
 703                         $inputOffset += 1;
 704                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 705                         # Step D, remove "^..$"
 706                         $inputOffset += 2;
 707                 } else {
 708                         # Step E, move leading path segment to output
 709                         if ( $prefixLengthOne == '/' ) {
 710                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 711                         } else {
 712                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 713                         }
 714                         if ( $slashPos === false ) {
 715                                 $output .= substr( $urlPath, $inputOffset );
 716                                 $inputOffset = $inputLength;
 717                         } else {
 718                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 719                                 $inputOffset += $slashPos - $inputOffset;
 720                         }
 721                 }
 722
 723                 if ( $trimOutput ) {
 724                         $slashPos = strrpos( $output, '/' );
 725                         if ( $slashPos === false ) {
 726                                 $output = '';
 727                         } else {
 728                                 $output = substr( $output, 0, $slashPos );
 729                         }
 730                 }
 731         }
 732
 733         return $output;
 734 }
 735
 736 /**
 737  * Returns a regular expression of url protocols
 738  *
 739  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 740  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 741  * @return string
 742  */
 743 function wfUrlProtocols( $includeProtocolRelative = true ) {
 744         global $wgUrlProtocols;
 745
 746         // Cache return values separately based on $includeProtocolRelative
 747         static $withProtRel = null, $withoutProtRel = null;
 748         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 749         if ( !is_null( $cachedValue ) ) {
 750                 return $cachedValue;
 751         }
 752
 753         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 754         // with LocalSettings files from 1.5
 755         if ( is_array( $wgUrlProtocols ) ) {
 756                 $protocols = [];
 757                 foreach ( $wgUrlProtocols as $protocol ) {
 758                         // Filter out '//' if !$includeProtocolRelative
 759                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 760                                 $protocols[] = preg_quote( $protocol, '/' );
 761                         }
 762                 }
 763
 764                 $retval = implode( '|', $protocols );
 765         } else {
 766                 // Ignore $includeProtocolRelative in this case
 767                 // This case exists for pre-1.6 compatibility, and we can safely assume
 768                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 769                 // URLs weren't supported until 1.18
 770                 $retval = $wgUrlProtocols;
 771         }
 772
 773         // Cache return value
 774         if ( $includeProtocolRelative ) {
 775                 $withProtRel = $retval;
 776         } else {
 777                 $withoutProtRel = $retval;
 778         }
 779         return $retval;
 780 }
 781
 782 /**
 783  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 784  * you need a regex that matches all URL protocols but does not match protocol-
 785  * relative URLs
 786  * @return string
 787  */
 788 function wfUrlProtocolsWithoutProtRel() {
 789         return wfUrlProtocols( false );
 790 }
 791
 792 /**
 793  * parse_url() work-alike, but non-broken.  Differences:
 794  *
 795  * 1) Does not raise warnings on bad URLs (just returns false).
 796  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 797  *    protocol-relative URLs) correctly.
 798  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 799  *
 800  * @param string $url A URL to parse
 801  * @return string[] Bits of the URL in an associative array, per PHP docs
 802  */
 803 function wfParseUrl( $url ) {
 804         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 805
 806         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 807         // bad that the easiest way to handle them is to just prepend 'http:' and
 808         // strip the protocol out later.
 809         $wasRelative = substr( $url, 0, 2 ) == '//';
 810         if ( $wasRelative ) {
 811                 $url = "http:$url";
 812         }
 813         MediaWiki\suppressWarnings();
 814         $bits = parse_url( $url );
 815         MediaWiki\restoreWarnings();
 816         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 817         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 818         if ( !$bits || !isset( $bits['scheme'] ) ) {
 819                 return false;
 820         }
 821
 822         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 823         $bits['scheme'] = strtolower( $bits['scheme'] );
 824
 825         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 826         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 827                 $bits['delimiter'] = '://';
 828         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 829                 $bits['delimiter'] = ':';
 830                 // parse_url detects for news: and mailto: the host part of an url as path
 831                 // We have to correct this wrong detection
 832                 if ( isset( $bits['path'] ) ) {
 833                         $bits['host'] = $bits['path'];
 834                         $bits['path'] = '';
 835                 }
 836         } else {
 837                 return false;
 838         }
 839
 840         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 841         if ( !isset( $bits['host'] ) ) {
 842                 $bits['host'] = '';
 843
 844                 // bug 45069
 845                 if ( isset( $bits['path'] ) ) {
 846                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 847                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 848                                 $bits['path'] = '/' . $bits['path'];
 849                         }
 850                 } else {
 851                         $bits['path'] = '';
 852                 }
 853         }
 854
 855         // If the URL was protocol-relative, fix scheme and delimiter
 856         if ( $wasRelative ) {
 857                 $bits['scheme'] = '';
 858                 $bits['delimiter'] = '//';
 859         }
 860         return $bits;
 861 }
 862
 863 /**
 864  * Take a URL, make sure it's expanded to fully qualified, and replace any
 865  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 866  * for more compact display and legibility for local audiences.
 867  *
 868  * @todo handle punycode domains too
 869  *
 870  * @param string $url
 871  * @return string
 872  */
 873 function wfExpandIRI( $url ) {
 874         return preg_replace_callback(
 875                 '/((?:%[89A-F][0-9A-F])+)/i',
 876                 'wfExpandIRI_callback',
 877                 wfExpandUrl( $url )
 878         );
 879 }
 880
 881 /**
 882  * Private callback for wfExpandIRI
 883  * @param array $matches
 884  * @return string
 885  */
 886 function wfExpandIRI_callback( $matches ) {
 887         return urldecode( $matches[1] );
 888 }
 889
 890 /**
 891  * Make URL indexes, appropriate for the el_index field of externallinks.
 892  *
 893  * @param string $url
 894  * @return array
 895  */
 896 function wfMakeUrlIndexes( $url ) {
 897         $bits = wfParseUrl( $url );
 898
 899         // Reverse the labels in the hostname, convert to lower case
 900         // For emails reverse domainpart only
 901         if ( $bits['scheme'] == 'mailto' ) {
 902                 $mailparts = explode( '@', $bits['host'], 2 );
 903                 if ( count( $mailparts ) === 2 ) {
 904                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 905                 } else {
 906                         // No domain specified, don't mangle it
 907                         $domainpart = '';
 908                 }
 909                 $reversedHost = $domainpart . '@' . $mailparts[0];
 910         } else {
 911                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 912         }
 913         // Add an extra dot to the end
 914         // Why? Is it in wrong place in mailto links?
 915         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 916                 $reversedHost .= '.';
 917         }
 918         // Reconstruct the pseudo-URL
 919         $prot = $bits['scheme'];
 920         $index = $prot . $bits['delimiter'] . $reversedHost;
 921         // Leave out user and password. Add the port, path, query and fragment
 922         if ( isset( $bits['port'] ) ) {
 923                 $index .= ':' . $bits['port'];
 924         }
 925         if ( isset( $bits['path'] ) ) {
 926                 $index .= $bits['path'];
 927         } else {
 928                 $index .= '/';
 929         }
 930         if ( isset( $bits['query'] ) ) {
 931                 $index .= '?' . $bits['query'];
 932         }
 933         if ( isset( $bits['fragment'] ) ) {
 934                 $index .= '#' . $bits['fragment'];
 935         }
 936
 937         if ( $prot == '' ) {
 938                 return [ "http:$index", "https:$index" ];
 939         } else {
 940                 return [ $index ];
 941         }
 942 }
 943
 944 /**
 945  * Check whether a given URL has a domain that occurs in a given set of domains
 946  * @param string $url URL
 947  * @param array $domains Array of domains (strings)
 948  * @return bool True if the host part of $url ends in one of the strings in $domains
 949  */
 950 function wfMatchesDomainList( $url, $domains ) {
 951         $bits = wfParseUrl( $url );
 952         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 953                 $host = '.' . $bits['host'];
 954                 foreach ( (array)$domains as $domain ) {
 955                         $domain = '.' . $domain;
 956                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 957                                 return true;
 958                         }
 959                 }
 960         }
 961         return false;
 962 }
 963
 964 /**
 965  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 966  * In normal operation this is a NOP.
 967  *
 968  * Controlling globals:
 969  * $wgDebugLogFile - points to the log file
 970  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 971  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 972  *
 973  * @since 1.25 support for additional context data
 974  *
 975  * @param string $text
 976  * @param string|bool $dest Destination of the message:
 977  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 978  *     - 'private': excluded from HTML output
 979  *   For backward compatibility, it can also take a boolean:
 980  *     - true: same as 'all'
 981  *     - false: same as 'private'
 982  * @param array $context Additional logging context data
 983  */
 984 function wfDebug( $text, $dest = 'all', array $context = [] ) {
 985         global $wgDebugRawPage, $wgDebugLogPrefix;
 986         global $wgDebugTimestamps, $wgRequestTime;
 987
 988         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 989                 return;
 990         }
 991
 992         $text = trim( $text );
 993
 994         if ( $wgDebugTimestamps ) {
 995                 $context['seconds_elapsed'] = sprintf(
 996                         '%6.4f',
 997                         microtime( true ) - $wgRequestTime
 998                 );
 999                 $context['memory_used'] = sprintf(
1000                         '%5.1fM',
1001                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1002                 );
1003         }
1004
1005         if ( $wgDebugLogPrefix !== '' ) {
1006                 $context['prefix'] = $wgDebugLogPrefix;
1007         }
1008         $context['private'] = ( $dest === false || $dest === 'private' );
1009
1010         $logger = LoggerFactory::getInstance( 'wfDebug' );
1011         $logger->debug( $text, $context );
1012 }
1013
1014 /**
1015  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1016  * @return bool
1017  */
1018 function wfIsDebugRawPage() {
1019         static $cache;
1020         if ( $cache !== null ) {
1021                 return $cache;
1022         }
1023         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1024         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1025                 || (
1026                         isset( $_SERVER['SCRIPT_NAME'] )
1027                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1028                 )
1029         ) {
1030                 $cache = true;
1031         } else {
1032                 $cache = false;
1033         }
1034         return $cache;
1035 }
1036
1037 /**
1038  * Send a line giving PHP memory usage.
1039  *
1040  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1041  */
1042 function wfDebugMem( $exact = false ) {
1043         $mem = memory_get_usage();
1044         if ( !$exact ) {
1045                 $mem = floor( $mem / 1024 ) . ' KiB';
1046         } else {
1047                 $mem .= ' B';
1048         }
1049         wfDebug( "Memory usage: $mem\n" );
1050 }
1051
1052 /**
1053  * Send a line to a supplementary debug log file, if configured, or main debug
1054  * log if not.
1055  *
1056  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1057  * a string filename or an associative array mapping 'destination' to the
1058  * desired filename. The associative array may also contain a 'sample' key
1059  * with an integer value, specifying a sampling factor. Sampled log events
1060  * will be emitted with a 1 in N random chance.
1061  *
1062  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1063  * @since 1.25 support for additional context data
1064  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1065  *
1066  * @param string $logGroup
1067  * @param string $text
1068  * @param string|bool $dest Destination of the message:
1069  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1070  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1071  *       discarded otherwise
1072  *   For backward compatibility, it can also take a boolean:
1073  *     - true: same as 'all'
1074  *     - false: same as 'private'
1075  * @param array $context Additional logging context data
1076  */
1077 function wfDebugLog(
1078         $logGroup, $text, $dest = 'all', array $context = []
1079 ) {
1080         $text = trim( $text );
1081
1082         $logger = LoggerFactory::getInstance( $logGroup );
1083         $context['private'] = ( $dest === false || $dest === 'private' );
1084         $logger->info( $text, $context );
1085 }
1086
1087 /**
1088  * Log for database errors
1089  *
1090  * @since 1.25 support for additional context data
1091  *
1092  * @param string $text Database error message.
1093  * @param array $context Additional logging context data
1094  */
1095 function wfLogDBError( $text, array $context = [] ) {
1096         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1097         $logger->error( trim( $text ), $context );
1098 }
1099
1100 /**
1101  * Throws a warning that $function is deprecated
1102  *
1103  * @param string $function
1104  * @param string|bool $version Version of MediaWiki that the function
1105  *    was deprecated in (Added in 1.19).
1106  * @param string|bool $component Added in 1.19.
1107  * @param int $callerOffset How far up the call stack is the original
1108  *    caller. 2 = function that called the function that called
1109  *    wfDeprecated (Added in 1.20)
1110  *
1111  * @return null
1112  */
1113 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1114         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1115 }
1116
1117 /**
1118  * Send a warning either to the debug log or in a PHP error depending on
1119  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1120  *
1121  * @param string $msg Message to send
1122  * @param int $callerOffset Number of items to go back in the backtrace to
1123  *        find the correct caller (1 = function calling wfWarn, ...)
1124  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1125  *        only used when $wgDevelopmentWarnings is true
1126  */
1127 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1128         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1129 }
1130
1131 /**
1132  * Send a warning as a PHP error and the debug log. This is intended for logging
1133  * warnings in production. For logging development warnings, use WfWarn instead.
1134  *
1135  * @param string $msg Message to send
1136  * @param int $callerOffset Number of items to go back in the backtrace to
1137  *        find the correct caller (1 = function calling wfLogWarning, ...)
1138  * @param int $level PHP error level; defaults to E_USER_WARNING
1139  */
1140 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1141         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1142 }
1143
1144 /**
1145  * Log to a file without getting "file size exceeded" signals.
1146  *
1147  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1148  * send lines to the specified port, prefixed by the specified prefix and a space.
1149  * @since 1.25 support for additional context data
1150  *
1151  * @param string $text
1152  * @param string $file Filename
1153  * @param array $context Additional logging context data
1154  * @throws MWException
1155  * @deprecated since 1.25 Use \MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1156  */
1157 function wfErrorLog( $text, $file, array $context = [] ) {
1158         wfDeprecated( __METHOD__, '1.25' );
1159         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1160         $context['destination'] = $file;
1161         $logger->info( trim( $text ), $context );
1162 }
1163
1164 /**
1165  * @todo document
1166  */
1167 function wfLogProfilingData() {
1168         global $wgDebugLogGroups, $wgDebugRawPage;
1169
1170         $context = RequestContext::getMain();
1171         $request = $context->getRequest();
1172
1173         $profiler = Profiler::instance();
1174         $profiler->setContext( $context );
1175         $profiler->logData();
1176
1177         $config = $context->getConfig();
1178         if ( $config->get( 'StatsdServer' ) ) {
1179                 try {
1180                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1181                         $statsdHost = $statsdServer[0];
1182                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1183                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1184                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1185                         $statsdClient->send( $context->getStats()->getBuffer() );
1186                 } catch ( Exception $ex ) {
1187                         MWExceptionHandler::logException( $ex );
1188                 }
1189         }
1190
1191         # Profiling must actually be enabled...
1192         if ( $profiler instanceof ProfilerStub ) {
1193                 return;
1194         }
1195
1196         if ( isset( $wgDebugLogGroups['profileoutput'] )
1197                 && $wgDebugLogGroups['profileoutput'] === false
1198         ) {
1199                 // Explicitly disabled
1200                 return;
1201         }
1202         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1203                 return;
1204         }
1205
1206         $ctx = [ 'elapsed' => $request->getElapsedTime() ];
1207         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1208                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1209         }
1210         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1211                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1212         }
1213         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1214                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1215         }
1216         if ( isset( $ctx['forwarded_for'] ) ||
1217                 isset( $ctx['client_ip'] ) ||
1218                 isset( $ctx['from'] ) ) {
1219                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1220         }
1221
1222         // Don't load $wgUser at this late stage just for statistics purposes
1223         // @todo FIXME: We can detect some anons even if it is not loaded.
1224         // See User::getId()
1225         $user = $context->getUser();
1226         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1227
1228         // Command line script uses a FauxRequest object which does not have
1229         // any knowledge about an URL and throw an exception instead.
1230         try {
1231                 $ctx['url'] = urldecode( $request->getRequestURL() );
1232         } catch ( Exception $ignored ) {
1233                 // no-op
1234         }
1235
1236         $ctx['output'] = $profiler->getOutput();
1237
1238         $log = LoggerFactory::getInstance( 'profileoutput' );
1239         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1240 }
1241
1242 /**
1243  * Increment a statistics counter
1244  *
1245  * @param string $key
1246  * @param int $count
1247  * @return void
1248  */
1249 function wfIncrStats( $key, $count = 1 ) {
1250         $stats = RequestContext::getMain()->getStats();
1251         $stats->updateCount( $key, $count );
1252 }
1253
1254 /**
1255  * Check whether the wiki is in read-only mode.
1256  *
1257  * @return bool
1258  */
1259 function wfReadOnly() {
1260         return wfReadOnlyReason() !== false;
1261 }
1262
1263 /**
1264  * Check if the site is in read-only mode and return the message if so
1265  *
1266  * This checks wfConfiguredReadOnlyReason() and the main load balancer
1267  * for slave lag. This may result in DB_SLAVE connection being made.
1268  *
1269  * @return string|bool String when in read-only mode; false otherwise
1270  */
1271 function wfReadOnlyReason() {
1272         $readOnly = wfConfiguredReadOnlyReason();
1273         if ( $readOnly !== false ) {
1274                 return $readOnly;
1275         }
1276
1277         static $lbReadOnly = null;
1278         if ( $lbReadOnly === null ) {
1279                 // Callers use this method to be aware that data presented to a user
1280                 // may be very stale and thus allowing submissions can be problematic.
1281                 $lbReadOnly = wfGetLB()->getReadOnlyReason();
1282         }
1283
1284         return $lbReadOnly;
1285 }
1286
1287 /**
1288  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1289  *
1290  * @return string|bool String when in read-only mode; false otherwise
1291  * @since 1.27
1292  */
1293 function wfConfiguredReadOnlyReason() {
1294         global $wgReadOnly, $wgReadOnlyFile;
1295
1296         if ( $wgReadOnly === null ) {
1297                 // Set $wgReadOnly for faster access next time
1298                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1299                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1300                 } else {
1301                         $wgReadOnly = false;
1302                 }
1303         }
1304
1305         return $wgReadOnly;
1306 }
1307
1308 /**
1309  * Return a Language object from $langcode
1310  *
1311  * @param Language|string|bool $langcode Either:
1312  *                  - a Language object
1313  *                  - code of the language to get the message for, if it is
1314  *                    a valid code create a language for that language, if
1315  *                    it is a string but not a valid code then make a basic
1316  *                    language object
1317  *                  - a boolean: if it's false then use the global object for
1318  *                    the current user's language (as a fallback for the old parameter
1319  *                    functionality), or if it is true then use global object
1320  *                    for the wiki's content language.
1321  * @return Language
1322  */
1323 function wfGetLangObj( $langcode = false ) {
1324         # Identify which language to get or create a language object for.
1325         # Using is_object here due to Stub objects.
1326         if ( is_object( $langcode ) ) {
1327                 # Great, we already have the object (hopefully)!
1328                 return $langcode;
1329         }
1330
1331         global $wgContLang, $wgLanguageCode;
1332         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1333                 # $langcode is the language code of the wikis content language object.
1334                 # or it is a boolean and value is true
1335                 return $wgContLang;
1336         }
1337
1338         global $wgLang;
1339         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1340                 # $langcode is the language code of user language object.
1341                 # or it was a boolean and value is false
1342                 return $wgLang;
1343         }
1344
1345         $validCodes = array_keys( Language::fetchLanguageNames() );
1346         if ( in_array( $langcode, $validCodes ) ) {
1347                 # $langcode corresponds to a valid language.
1348                 return Language::factory( $langcode );
1349         }
1350
1351         # $langcode is a string, but not a valid language code; use content language.
1352         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1353         return $wgContLang;
1354 }
1355
1356 /**
1357  * This is the function for getting translated interface messages.
1358  *
1359  * @see Message class for documentation how to use them.
1360  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1361  *
1362  * This function replaces all old wfMsg* functions.
1363  *
1364  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1365  * @param mixed $params,... Normal message parameters
1366  * @return Message
1367  *
1368  * @since 1.17
1369  *
1370  * @see Message::__construct
1371  */
1372 function wfMessage( $key /*...*/ ) {
1373         $params = func_get_args();
1374         array_shift( $params );
1375         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1376                 $params = $params[0];
1377         }
1378         return new Message( $key, $params );
1379 }
1380
1381 /**
1382  * This function accepts multiple message keys and returns a message instance
1383  * for the first message which is non-empty. If all messages are empty then an
1384  * instance of the first message key is returned.
1385  *
1386  * @param string|string[] $keys,... Message keys
1387  * @return Message
1388  *
1389  * @since 1.18
1390  *
1391  * @see Message::newFallbackSequence
1392  */
1393 function wfMessageFallback( /*...*/ ) {
1394         $args = func_get_args();
1395         return call_user_func_array( 'Message::newFallbackSequence', $args );
1396 }
1397
1398 /**
1399  * Replace message parameter keys on the given formatted output.
1400  *
1401  * @param string $message
1402  * @param array $args
1403  * @return string
1404  * @private
1405  */
1406 function wfMsgReplaceArgs( $message, $args ) {
1407         # Fix windows line-endings
1408         # Some messages are split with explode("\n", $msg)
1409         $message = str_replace( "\r", '', $message );
1410
1411         // Replace arguments
1412         if ( is_array( $args ) && $args ) {
1413                 if ( is_array( $args[0] ) ) {
1414                         $args = array_values( $args[0] );
1415                 }
1416                 $replacementKeys = [];
1417                 foreach ( $args as $n => $param ) {
1418                         $replacementKeys['$' . ( $n + 1 )] = $param;
1419                 }
1420                 $message = strtr( $message, $replacementKeys );
1421         }
1422
1423         return $message;
1424 }
1425
1426 /**
1427  * Fetch server name for use in error reporting etc.
1428  * Use real server name if available, so we know which machine
1429  * in a server farm generated the current page.
1430  *
1431  * @return string
1432  */
1433 function wfHostname() {
1434         static $host;
1435         if ( is_null( $host ) ) {
1436
1437                 # Hostname overriding
1438                 global $wgOverrideHostname;
1439                 if ( $wgOverrideHostname !== false ) {
1440                         # Set static and skip any detection
1441                         $host = $wgOverrideHostname;
1442                         return $host;
1443                 }
1444
1445                 if ( function_exists( 'posix_uname' ) ) {
1446                         // This function not present on Windows
1447                         $uname = posix_uname();
1448                 } else {
1449                         $uname = false;
1450                 }
1451                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1452                         $host = $uname['nodename'];
1453                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1454                         # Windows computer name
1455                         $host = getenv( 'COMPUTERNAME' );
1456                 } else {
1457                         # This may be a virtual server.
1458                         $host = $_SERVER['SERVER_NAME'];
1459                 }
1460         }
1461         return $host;
1462 }
1463
1464 /**
1465  * Returns a script tag that stores the amount of time it took MediaWiki to
1466  * handle the request in milliseconds as 'wgBackendResponseTime'.
1467  *
1468  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1469  * hostname of the server handling the request.
1470  *
1471  * @return string
1472  */
1473 function wfReportTime() {
1474         global $wgRequestTime, $wgShowHostnames;
1475
1476         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1477         $reportVars = [ 'wgBackendResponseTime' => $responseTime ];
1478         if ( $wgShowHostnames ) {
1479                 $reportVars['wgHostname'] = wfHostname();
1480         }
1481         return Skin::makeVariablesScript( $reportVars );
1482 }
1483
1484 /**
1485  * Safety wrapper for debug_backtrace().
1486  *
1487  * Will return an empty array if debug_backtrace is disabled, otherwise
1488  * the output from debug_backtrace() (trimmed).
1489  *
1490  * @param int $limit This parameter can be used to limit the number of stack frames returned
1491  *
1492  * @return array Array of backtrace information
1493  */
1494 function wfDebugBacktrace( $limit = 0 ) {
1495         static $disabled = null;
1496
1497         if ( is_null( $disabled ) ) {
1498                 $disabled = !function_exists( 'debug_backtrace' );
1499                 if ( $disabled ) {
1500                         wfDebug( "debug_backtrace() is disabled\n" );
1501                 }
1502         }
1503         if ( $disabled ) {
1504                 return [];
1505         }
1506
1507         if ( $limit ) {
1508                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1509         } else {
1510                 return array_slice( debug_backtrace(), 1 );
1511         }
1512 }
1513
1514 /**
1515  * Get a debug backtrace as a string
1516  *
1517  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1518  *   Defaults to $wgCommandLineMode if unset.
1519  * @return string
1520  * @since 1.25 Supports $raw parameter.
1521  */
1522 function wfBacktrace( $raw = null ) {
1523         global $wgCommandLineMode;
1524
1525         if ( $raw === null ) {
1526                 $raw = $wgCommandLineMode;
1527         }
1528
1529         if ( $raw ) {
1530                 $frameFormat = "%s line %s calls %s()\n";
1531                 $traceFormat = "%s";
1532         } else {
1533                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1534                 $traceFormat = "<ul>\n%s</ul>\n";
1535         }
1536
1537         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1538                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1539                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1540                 $call = $frame['function'];
1541                 if ( !empty( $frame['class'] ) ) {
1542                         $call = $frame['class'] . $frame['type'] . $call;
1543                 }
1544                 return sprintf( $frameFormat, $file, $line, $call );
1545         }, wfDebugBacktrace() );
1546
1547         return sprintf( $traceFormat, implode( '', $frames ) );
1548 }
1549
1550 /**
1551  * Get the name of the function which called this function
1552  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1553  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1554  * wfGetCaller( 3 ) is the parent of that.
1555  *
1556  * @param int $level
1557  * @return string
1558  */
1559 function wfGetCaller( $level = 2 ) {
1560         $backtrace = wfDebugBacktrace( $level + 1 );
1561         if ( isset( $backtrace[$level] ) ) {
1562                 return wfFormatStackFrame( $backtrace[$level] );
1563         } else {
1564                 return 'unknown';
1565         }
1566 }
1567
1568 /**
1569  * Return a string consisting of callers in the stack. Useful sometimes
1570  * for profiling specific points.
1571  *
1572  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1573  * @return string
1574  */
1575 function wfGetAllCallers( $limit = 3 ) {
1576         $trace = array_reverse( wfDebugBacktrace() );
1577         if ( !$limit || $limit > count( $trace ) - 1 ) {
1578                 $limit = count( $trace ) - 1;
1579         }
1580         $trace = array_slice( $trace, -$limit - 1, $limit );
1581         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1582 }
1583
1584 /**
1585  * Return a string representation of frame
1586  *
1587  * @param array $frame
1588  * @return string
1589  */
1590 function wfFormatStackFrame( $frame ) {
1591         if ( !isset( $frame['function'] ) ) {
1592                 return 'NO_FUNCTION_GIVEN';
1593         }
1594         return isset( $frame['class'] ) && isset( $frame['type'] ) ?
1595                 $frame['class'] . $frame['type'] . $frame['function'] :
1596                 $frame['function'];
1597 }
1598
1599 /* Some generic result counters, pulled out of SearchEngine */
1600
1601 /**
1602  * @todo document
1603  *
1604  * @param int $offset
1605  * @param int $limit
1606  * @return string
1607  */
1608 function wfShowingResults( $offset, $limit ) {
1609         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1610 }
1611
1612 /**
1613  * @todo document
1614  * @todo FIXME: We may want to blacklist some broken browsers
1615  *
1616  * @param bool $force
1617  * @return bool Whereas client accept gzip compression
1618  */
1619 function wfClientAcceptsGzip( $force = false ) {
1620         static $result = null;
1621         if ( $result === null || $force ) {
1622                 $result = false;
1623                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1624                         # @todo FIXME: We may want to blacklist some broken browsers
1625                         $m = [];
1626                         if ( preg_match(
1627                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1628                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1629                                         $m
1630                                 )
1631                         ) {
1632                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1633                                         $result = false;
1634                                         return $result;
1635                                 }
1636                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1637                                 $result = true;
1638                         }
1639                 }
1640         }
1641         return $result;
1642 }
1643
1644 /**
1645  * Escapes the given text so that it may be output using addWikiText()
1646  * without any linking, formatting, etc. making its way through. This
1647  * is achieved by substituting certain characters with HTML entities.
1648  * As required by the callers, "<nowiki>" is not used.
1649  *
1650  * @param string $text Text to be escaped
1651  * @return string
1652  */
1653 function wfEscapeWikiText( $text ) {
1654         static $repl = null, $repl2 = null;
1655         if ( $repl === null ) {
1656                 $repl = [
1657                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1658                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1659                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1660                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1661                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1662                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1663                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1664                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1665                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1666                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1667                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1668                         '__' => '_&#95;', '://' => '&#58;//',
1669                 ];
1670
1671                 // We have to catch everything "\s" matches in PCRE
1672                 foreach ( [ 'ISBN', 'RFC', 'PMID' ] as $magic ) {
1673                         $repl["$magic "] = "$magic&#32;";
1674                         $repl["$magic\t"] = "$magic&#9;";
1675                         $repl["$magic\r"] = "$magic&#13;";
1676                         $repl["$magic\n"] = "$magic&#10;";
1677                         $repl["$magic\f"] = "$magic&#12;";
1678                 }
1679
1680                 // And handle protocols that don't use "://"
1681                 global $wgUrlProtocols;
1682                 $repl2 = [];
1683                 foreach ( $wgUrlProtocols as $prot ) {
1684                         if ( substr( $prot, -1 ) === ':' ) {
1685                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1686                         }
1687                 }
1688                 $repl2 = $repl2 ? '/\b(' . implode( '|', $repl2 ) . '):/i' : '/^(?!)/';
1689         }
1690         $text = substr( strtr( "\n$text", $repl ), 1 );
1691         $text = preg_replace( $repl2, '$1&#58;', $text );
1692         return $text;
1693 }
1694
1695 /**
1696  * Sets dest to source and returns the original value of dest
1697  * If source is NULL, it just returns the value, it doesn't set the variable
1698  * If force is true, it will set the value even if source is NULL
1699  *
1700  * @param mixed $dest
1701  * @param mixed $source
1702  * @param bool $force
1703  * @return mixed
1704  */
1705 function wfSetVar( &$dest, $source, $force = false ) {
1706         $temp = $dest;
1707         if ( !is_null( $source ) || $force ) {
1708                 $dest = $source;
1709         }
1710         return $temp;
1711 }
1712
1713 /**
1714  * As for wfSetVar except setting a bit
1715  *
1716  * @param int $dest
1717  * @param int $bit
1718  * @param bool $state
1719  *
1720  * @return bool
1721  */
1722 function wfSetBit( &$dest, $bit, $state = true ) {
1723         $temp = (bool)( $dest & $bit );
1724         if ( !is_null( $state ) ) {
1725                 if ( $state ) {
1726                         $dest |= $bit;
1727                 } else {
1728                         $dest &= ~$bit;
1729                 }
1730         }
1731         return $temp;
1732 }
1733
1734 /**
1735  * A wrapper around the PHP function var_export().
1736  * Either print it or add it to the regular output ($wgOut).
1737  *
1738  * @param mixed $var A PHP variable to dump.
1739  */
1740 function wfVarDump( $var ) {
1741         global $wgOut;
1742         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1743         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1744                 print $s;
1745         } else {
1746                 $wgOut->addHTML( $s );
1747         }
1748 }
1749
1750 /**
1751  * Provide a simple HTTP error.
1752  *
1753  * @param int|string $code
1754  * @param string $label
1755  * @param string $desc
1756  */
1757 function wfHttpError( $code, $label, $desc ) {
1758         global $wgOut;
1759         HttpStatus::header( $code );
1760         if ( $wgOut ) {
1761                 $wgOut->disable();
1762                 $wgOut->sendCacheControl();
1763         }
1764
1765         header( 'Content-type: text/html; charset=utf-8' );
1766         print '<!DOCTYPE html>' .
1767                 '<html><head><title>' .
1768                 htmlspecialchars( $label ) .
1769                 '</title></head><body><h1>' .
1770                 htmlspecialchars( $label ) .
1771                 '</h1><p>' .
1772                 nl2br( htmlspecialchars( $desc ) ) .
1773                 "</p></body></html>\n";
1774 }
1775
1776 /**
1777  * Clear away any user-level output buffers, discarding contents.
1778  *
1779  * Suitable for 'starting afresh', for instance when streaming
1780  * relatively large amounts of data without buffering, or wanting to
1781  * output image files without ob_gzhandler's compression.
1782  *
1783  * The optional $resetGzipEncoding parameter controls suppression of
1784  * the Content-Encoding header sent by ob_gzhandler; by default it
1785  * is left. See comments for wfClearOutputBuffers() for why it would
1786  * be used.
1787  *
1788  * Note that some PHP configuration options may add output buffer
1789  * layers which cannot be removed; these are left in place.
1790  *
1791  * @param bool $resetGzipEncoding
1792  */
1793 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1794         if ( $resetGzipEncoding ) {
1795                 // Suppress Content-Encoding and Content-Length
1796                 // headers from 1.10+s wfOutputHandler
1797                 global $wgDisableOutputCompression;
1798                 $wgDisableOutputCompression = true;
1799         }
1800         while ( $status = ob_get_status() ) {
1801                 if ( isset( $status['flags'] ) ) {
1802                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
1803                         $deleteable = ( $status['flags'] & $flags ) === $flags;
1804                 } elseif ( isset( $status['del'] ) ) {
1805                         $deleteable = $status['del'];
1806                 } else {
1807                         // Guess that any PHP-internal setting can't be removed.
1808                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
1809                 }
1810                 if ( !$deleteable ) {
1811                         // Give up, and hope the result doesn't break
1812                         // output behavior.
1813                         break;
1814                 }
1815                 if ( $status['name'] === 'MediaWikiTestCase::wfResetOutputBuffersBarrier' ) {
1816                         // Unit testing barrier to prevent this function from breaking PHPUnit.
1817                         break;
1818                 }
1819                 if ( !ob_end_clean() ) {
1820                         // Could not remove output buffer handler; abort now
1821                         // to avoid getting in some kind of infinite loop.
1822                         break;
1823                 }
1824                 if ( $resetGzipEncoding ) {
1825                         if ( $status['name'] == 'ob_gzhandler' ) {
1826                                 // Reset the 'Content-Encoding' field set by this handler
1827                                 // so we can start fresh.
1828                                 header_remove( 'Content-Encoding' );
1829                                 break;
1830                         }
1831                 }
1832         }
1833 }
1834
1835 /**
1836  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1837  *
1838  * Clear away output buffers, but keep the Content-Encoding header
1839  * produced by ob_gzhandler, if any.
1840  *
1841  * This should be used for HTTP 304 responses, where you need to
1842  * preserve the Content-Encoding header of the real result, but
1843  * also need to suppress the output of ob_gzhandler to keep to spec
1844  * and avoid breaking Firefox in rare cases where the headers and
1845  * body are broken over two packets.
1846  */
1847 function wfClearOutputBuffers() {
1848         wfResetOutputBuffers( false );
1849 }
1850
1851 /**
1852  * Converts an Accept-* header into an array mapping string values to quality
1853  * factors
1854  *
1855  * @param string $accept
1856  * @param string $def Default
1857  * @return float[] Associative array of string => float pairs
1858  */
1859 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1860         # No arg means accept anything (per HTTP spec)
1861         if ( !$accept ) {
1862                 return [ $def => 1.0 ];
1863         }
1864
1865         $prefs = [];
1866
1867         $parts = explode( ',', $accept );
1868
1869         foreach ( $parts as $part ) {
1870                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1871                 $values = explode( ';', trim( $part ) );
1872                 $match = [];
1873                 if ( count( $values ) == 1 ) {
1874                         $prefs[$values[0]] = 1.0;
1875                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1876                         $prefs[$values[0]] = floatval( $match[1] );
1877                 }
1878         }
1879
1880         return $prefs;
1881 }
1882
1883 /**
1884  * Checks if a given MIME type matches any of the keys in the given
1885  * array. Basic wildcards are accepted in the array keys.
1886  *
1887  * Returns the matching MIME type (or wildcard) if a match, otherwise
1888  * NULL if no match.
1889  *
1890  * @param string $type
1891  * @param array $avail
1892  * @return string
1893  * @private
1894  */
1895 function mimeTypeMatch( $type, $avail ) {
1896         if ( array_key_exists( $type, $avail ) ) {
1897                 return $type;
1898         } else {
1899                 $mainType = explode( '/', $type )[0];
1900                 if ( array_key_exists( "$mainType/*", $avail ) ) {
1901                         return "$mainType/*";
1902                 } elseif ( array_key_exists( '*/*', $avail ) ) {
1903                         return '*/*';
1904                 } else {
1905                         return null;
1906                 }
1907         }
1908 }
1909
1910 /**
1911  * Returns the 'best' match between a client's requested internet media types
1912  * and the server's list of available types. Each list should be an associative
1913  * array of type to preference (preference is a float between 0.0 and 1.0).
1914  * Wildcards in the types are acceptable.
1915  *
1916  * @param array $cprefs Client's acceptable type list
1917  * @param array $sprefs Server's offered types
1918  * @return string
1919  *
1920  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1921  * XXX: generalize to negotiate other stuff
1922  */
1923 function wfNegotiateType( $cprefs, $sprefs ) {
1924         $combine = [];
1925
1926         foreach ( array_keys( $sprefs ) as $type ) {
1927                 $subType = explode( '/', $type )[1];
1928                 if ( $subType != '*' ) {
1929                         $ckey = mimeTypeMatch( $type, $cprefs );
1930                         if ( $ckey ) {
1931                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1932                         }
1933                 }
1934         }
1935
1936         foreach ( array_keys( $cprefs ) as $type ) {
1937                 $subType = explode( '/', $type )[1];
1938                 if ( $subType != '*' && !array_key_exists( $type, $sprefs ) ) {
1939                         $skey = mimeTypeMatch( $type, $sprefs );
1940                         if ( $skey ) {
1941                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1942                         }
1943                 }
1944         }
1945
1946         $bestq = 0;
1947         $besttype = null;
1948
1949         foreach ( array_keys( $combine ) as $type ) {
1950                 if ( $combine[$type] > $bestq ) {
1951                         $besttype = $type;
1952                         $bestq = $combine[$type];
1953                 }
1954         }
1955
1956         return $besttype;
1957 }
1958
1959 /**
1960  * Reference-counted warning suppression
1961  *
1962  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
1963  * @param bool $end
1964  */
1965 function wfSuppressWarnings( $end = false ) {
1966         MediaWiki\suppressWarnings( $end );
1967 }
1968
1969 /**
1970  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
1971  * Restore error level to previous value
1972  */
1973 function wfRestoreWarnings() {
1974         MediaWiki\suppressWarnings( true );
1975 }
1976
1977 # Autodetect, convert and provide timestamps of various types
1978
1979 /**
1980  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
1981  */
1982 define( 'TS_UNIX', 0 );
1983
1984 /**
1985  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
1986  */
1987 define( 'TS_MW', 1 );
1988
1989 /**
1990  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
1991  */
1992 define( 'TS_DB', 2 );
1993
1994 /**
1995  * RFC 2822 format, for E-mail and HTTP headers
1996  */
1997 define( 'TS_RFC2822', 3 );
1998
1999 /**
2000  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2001  *
2002  * This is used by Special:Export
2003  */
2004 define( 'TS_ISO_8601', 4 );
2005
2006 /**
2007  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2008  *
2009  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2010  *       DateTime tag and page 36 for the DateTimeOriginal and
2011  *       DateTimeDigitized tags.
2012  */
2013 define( 'TS_EXIF', 5 );
2014
2015 /**
2016  * Oracle format time.
2017  */
2018 define( 'TS_ORACLE', 6 );
2019
2020 /**
2021  * Postgres format time.
2022  */
2023 define( 'TS_POSTGRES', 7 );
2024
2025 /**
2026  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2027  */
2028 define( 'TS_ISO_8601_BASIC', 9 );
2029
2030 /**
2031  * Get a timestamp string in one of various formats
2032  *
2033  * @param mixed $outputtype A timestamp in one of the supported formats, the
2034  *   function will autodetect which format is supplied and act accordingly.
2035  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2036  * @return string|bool String / false The same date in the format specified in $outputtype or false
2037  */
2038 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2039         try {
2040                 $timestamp = new MWTimestamp( $ts );
2041                 return $timestamp->getTimestamp( $outputtype );
2042         } catch ( TimestampException $e ) {
2043                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2044                 return false;
2045         }
2046 }
2047
2048 /**
2049  * Return a formatted timestamp, or null if input is null.
2050  * For dealing with nullable timestamp columns in the database.
2051  *
2052  * @param int $outputtype
2053  * @param string $ts
2054  * @return string
2055  */
2056 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2057         if ( is_null( $ts ) ) {
2058                 return null;
2059         } else {
2060                 return wfTimestamp( $outputtype, $ts );
2061         }
2062 }
2063
2064 /**
2065  * Convenience function; returns MediaWiki timestamp for the present time.
2066  *
2067  * @return string
2068  */
2069 function wfTimestampNow() {
2070         # return NOW
2071         return wfTimestamp( TS_MW, time() );
2072 }
2073
2074 /**
2075  * Check if the operating system is Windows
2076  *
2077  * @return bool True if it's Windows, false otherwise.
2078  */
2079 function wfIsWindows() {
2080         static $isWindows = null;
2081         if ( $isWindows === null ) {
2082                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2083         }
2084         return $isWindows;
2085 }
2086
2087 /**
2088  * Check if we are running under HHVM
2089  *
2090  * @return bool
2091  */
2092 function wfIsHHVM() {
2093         return defined( 'HHVM_VERSION' );
2094 }
2095
2096 /**
2097  * Tries to get the system directory for temporary files. First
2098  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2099  * environment variables are then checked in sequence, then
2100  * sys_get_temp_dir(), then upload_tmp_dir from php.ini.
2101  *
2102  * NOTE: When possible, use instead the tmpfile() function to create
2103  * temporary files to avoid race conditions on file creation, etc.
2104  *
2105  * @return string
2106  */
2107 function wfTempDir() {
2108         global $wgTmpDirectory;
2109
2110         if ( $wgTmpDirectory !== false ) {
2111                 return $wgTmpDirectory;
2112         }
2113
2114         $tmpDir = array_map( "getenv", [ 'TMPDIR', 'TMP', 'TEMP' ] );
2115         $tmpDir[] = sys_get_temp_dir();
2116         $tmpDir[] = ini_get( 'upload_tmp_dir' );
2117
2118         foreach ( $tmpDir as $tmp ) {
2119                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2120                         return $tmp;
2121                 }
2122         }
2123         throw new MWException( 'No writable temporary directory could be found. ' .
2124                 'Please set $wgTmpDirectory to a writable directory.' );
2125 }
2126
2127 /**
2128  * Make directory, and make all parent directories if they don't exist
2129  *
2130  * @param string $dir Full path to directory to create
2131  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2132  * @param string $caller Optional caller param for debugging.
2133  * @throws MWException
2134  * @return bool
2135  */
2136 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2137         global $wgDirectoryMode;
2138
2139         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2140                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2141         }
2142
2143         if ( !is_null( $caller ) ) {
2144                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2145         }
2146
2147         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2148                 return true;
2149         }
2150
2151         $dir = str_replace( [ '\\', '/' ], DIRECTORY_SEPARATOR, $dir );
2152
2153         if ( is_null( $mode ) ) {
2154                 $mode = $wgDirectoryMode;
2155         }
2156
2157         // Turn off the normal warning, we're doing our own below
2158         MediaWiki\suppressWarnings();
2159         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2160         MediaWiki\restoreWarnings();
2161
2162         if ( !$ok ) {
2163                 // directory may have been created on another request since we last checked
2164                 if ( is_dir( $dir ) ) {
2165                         return true;
2166                 }
2167
2168                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2169                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2170         }
2171         return $ok;
2172 }
2173
2174 /**
2175  * Remove a directory and all its content.
2176  * Does not hide error.
2177  * @param string $dir
2178  */
2179 function wfRecursiveRemoveDir( $dir ) {
2180         wfDebug( __FUNCTION__ . "( $dir )\n" );
2181         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2182         if ( is_dir( $dir ) ) {
2183                 $objects = scandir( $dir );
2184                 foreach ( $objects as $object ) {
2185                         if ( $object != "." && $object != ".." ) {
2186                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2187                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2188                                 } else {
2189                                         unlink( $dir . '/' . $object );
2190                                 }
2191                         }
2192                 }
2193                 reset( $objects );
2194                 rmdir( $dir );
2195         }
2196 }
2197
2198 /**
2199  * @param int $nr The number to format
2200  * @param int $acc The number of digits after the decimal point, default 2
2201  * @param bool $round Whether or not to round the value, default true
2202  * @return string
2203  */
2204 function wfPercent( $nr, $acc = 2, $round = true ) {
2205         $ret = sprintf( "%.${acc}f", $nr );
2206         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2207 }
2208
2209 /**
2210  * Safety wrapper around ini_get() for boolean settings.
2211  * The values returned from ini_get() are pre-normalized for settings
2212  * set via php.ini or php_flag/php_admin_flag... but *not*
2213  * for those set via php_value/php_admin_value.
2214  *
2215  * It's fairly common for people to use php_value instead of php_flag,
2216  * which can leave you with an 'off' setting giving a false positive
2217  * for code that just takes the ini_get() return value as a boolean.
2218  *
2219  * To make things extra interesting, setting via php_value accepts
2220  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2221  * Unrecognized values go false... again opposite PHP's own coercion
2222  * from string to bool.
2223  *
2224  * Luckily, 'properly' set settings will always come back as '0' or '1',
2225  * so we only have to worry about them and the 'improper' settings.
2226  *
2227  * I frickin' hate PHP... :P
2228  *
2229  * @param string $setting
2230  * @return bool
2231  */
2232 function wfIniGetBool( $setting ) {
2233         $val = strtolower( ini_get( $setting ) );
2234         // 'on' and 'true' can't have whitespace around them, but '1' can.
2235         return $val == 'on'
2236                 || $val == 'true'
2237                 || $val == 'yes'
2238                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2239 }
2240
2241 /**
2242  * Windows-compatible version of escapeshellarg()
2243  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2244  * function puts single quotes in regardless of OS.
2245  *
2246  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2247  * earlier distro releases of PHP)
2248  *
2249  * @param string ... strings to escape and glue together, or a single array of strings parameter
2250  * @return string
2251  */
2252 function wfEscapeShellArg( /*...*/ ) {
2253         wfInitShellLocale();
2254
2255         $args = func_get_args();
2256         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2257                 // If only one argument has been passed, and that argument is an array,
2258                 // treat it as a list of arguments
2259                 $args = reset( $args );
2260         }
2261
2262         $first = true;
2263         $retVal = '';
2264         foreach ( $args as $arg ) {
2265                 if ( !$first ) {
2266                         $retVal .= ' ';
2267                 } else {
2268                         $first = false;
2269                 }
2270
2271                 if ( wfIsWindows() ) {
2272                         // Escaping for an MSVC-style command line parser and CMD.EXE
2273                         // @codingStandardsIgnoreStart For long URLs
2274                         // Refs:
2275                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2276                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2277                         //  * Bug #13518
2278                         //  * CR r63214
2279                         // Double the backslashes before any double quotes. Escape the double quotes.
2280                         // @codingStandardsIgnoreEnd
2281                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2282                         $arg = '';
2283                         $iteration = 0;
2284                         foreach ( $tokens as $token ) {
2285                                 if ( $iteration % 2 == 1 ) {
2286                                         // Delimiter, a double quote preceded by zero or more slashes
2287                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2288                                 } elseif ( $iteration % 4 == 2 ) {
2289                                         // ^ in $token will be outside quotes, need to be escaped
2290                                         $arg .= str_replace( '^', '^^', $token );
2291                                 } else { // $iteration % 4 == 0
2292                                         // ^ in $token will appear inside double quotes, so leave as is
2293                                         $arg .= $token;
2294                                 }
2295                                 $iteration++;
2296                         }
2297                         // Double the backslashes before the end of the string, because
2298                         // we will soon add a quote
2299                         $m = [];
2300                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2301                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2302                         }
2303
2304                         // Add surrounding quotes
2305                         $retVal .= '"' . $arg . '"';
2306                 } else {
2307                         $retVal .= escapeshellarg( $arg );
2308                 }
2309         }
2310         return $retVal;
2311 }
2312
2313 /**
2314  * Check if wfShellExec() is effectively disabled via php.ini config
2315  *
2316  * @return bool|string False or 'disabled'
2317  * @since 1.22
2318  */
2319 function wfShellExecDisabled() {
2320         static $disabled = null;
2321         if ( is_null( $disabled ) ) {
2322                 if ( !function_exists( 'proc_open' ) ) {
2323                         wfDebug( "proc_open() is disabled\n" );
2324                         $disabled = 'disabled';
2325                 } else {
2326                         $disabled = false;
2327                 }
2328         }
2329         return $disabled;
2330 }
2331
2332 /**
2333  * Execute a shell command, with time and memory limits mirrored from the PHP
2334  * configuration if supported.
2335  *
2336  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2337  *   or an array of unescaped arguments, in which case each value will be escaped
2338  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2339  * @param null|mixed &$retval Optional, will receive the program's exit code.
2340  *   (non-zero is usually failure). If there is an error from
2341  *   read, select, or proc_open(), this will be set to -1.
2342  * @param array $environ Optional environment variables which should be
2343  *   added to the executed command environment.
2344  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2345  *   this overwrites the global wgMaxShell* limits.
2346  * @param array $options Array of options:
2347  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2348  *     including errors from limit.sh
2349  *   - profileMethod: By default this function will profile based on the calling
2350  *     method. Set this to a string for an alternative method to profile from
2351  *
2352  * @return string Collected stdout as a string
2353  */
2354 function wfShellExec( $cmd, &$retval = null, $environ = [],
2355         $limits = [], $options = []
2356 ) {
2357         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2358                 $wgMaxShellWallClockTime, $wgShellCgroup;
2359
2360         $disabled = wfShellExecDisabled();
2361         if ( $disabled ) {
2362                 $retval = 1;
2363                 return 'Unable to run external programs, proc_open() is disabled.';
2364         }
2365
2366         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2367         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2368
2369         wfInitShellLocale();
2370
2371         $envcmd = '';
2372         foreach ( $environ as $k => $v ) {
2373                 if ( wfIsWindows() ) {
2374                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2375                          * appear in the environment variable, so we must use carat escaping as documented in
2376                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2377                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2378                          * are listed there but doesn't appear to need it.
2379                          */
2380                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2381                 } else {
2382                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2383                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2384                          */
2385                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2386                 }
2387         }
2388         if ( is_array( $cmd ) ) {
2389                 $cmd = wfEscapeShellArg( $cmd );
2390         }
2391
2392         $cmd = $envcmd . $cmd;
2393
2394         $useLogPipe = false;
2395         if ( is_executable( '/bin/bash' ) ) {
2396                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2397                 if ( isset( $limits['walltime'] ) ) {
2398                         $wallTime = intval( $limits['walltime'] );
2399                 } elseif ( isset( $limits['time'] ) ) {
2400                         $wallTime = $time;
2401                 } else {
2402                         $wallTime = intval( $wgMaxShellWallClockTime );
2403                 }
2404                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2405                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2406
2407                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2408                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2409                                 escapeshellarg( $cmd ) . ' ' .
2410                                 escapeshellarg(
2411                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2412                                         "MW_CPU_LIMIT=$time; " .
2413                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2414                                         "MW_MEM_LIMIT=$mem; " .
2415                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2416                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2417                                         "MW_USE_LOG_PIPE=yes"
2418                                 );
2419                         $useLogPipe = true;
2420                 } elseif ( $includeStderr ) {
2421                         $cmd .= ' 2>&1';
2422                 }
2423         } elseif ( $includeStderr ) {
2424                 $cmd .= ' 2>&1';
2425         }
2426         wfDebug( "wfShellExec: $cmd\n" );
2427
2428         $desc = [
2429                 0 => [ 'file', 'php://stdin', 'r' ],
2430                 1 => [ 'pipe', 'w' ],
2431                 2 => [ 'file', 'php://stderr', 'w' ] ];
2432         if ( $useLogPipe ) {
2433                 $desc[3] = [ 'pipe', 'w' ];
2434         }
2435         $pipes = null;
2436         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2437         $proc = proc_open( $cmd, $desc, $pipes );
2438         if ( !$proc ) {
2439                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2440                 $retval = -1;
2441                 return '';
2442         }
2443         $outBuffer = $logBuffer = '';
2444         $emptyArray = [];
2445         $status = false;
2446         $logMsg = false;
2447
2448         /* According to the documentation, it is possible for stream_select()
2449          * to fail due to EINTR. I haven't managed to induce this in testing
2450          * despite sending various signals. If it did happen, the error
2451          * message would take the form:
2452          *
2453          * stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2454          *
2455          * where [4] is the value of the macro EINTR and "Interrupted system
2456          * call" is string which according to the Linux manual is "possibly"
2457          * localised according to LC_MESSAGES.
2458          */
2459         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2460         $eintrMessage = "stream_select(): unable to select [$eintr]";
2461
2462         // Build a table mapping resource IDs to pipe FDs to work around a
2463         // PHP 5.3 issue in which stream_select() does not preserve array keys
2464         // <https://bugs.php.net/bug.php?id=53427>.
2465         $fds = [];
2466         foreach ( $pipes as $fd => $pipe ) {
2467                 $fds[(int)$pipe] = $fd;
2468         }
2469
2470         $running = true;
2471         $timeout = null;
2472         $numReadyPipes = 0;
2473
2474         while ( $running === true || $numReadyPipes !== 0 ) {
2475                 if ( $running ) {
2476                         $status = proc_get_status( $proc );
2477                         // If the process has terminated, switch to nonblocking selects
2478                         // for getting any data still waiting to be read.
2479                         if ( !$status['running'] ) {
2480                                 $running = false;
2481                                 $timeout = 0;
2482                         }
2483                 }
2484
2485                 $readyPipes = $pipes;
2486
2487                 // Clear last error
2488                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2489                 @trigger_error( '' );
2490                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2491                 if ( $numReadyPipes === false ) {
2492                         // @codingStandardsIgnoreEnd
2493                         $error = error_get_last();
2494                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2495                                 continue;
2496                         } else {
2497                                 trigger_error( $error['message'], E_USER_WARNING );
2498                                 $logMsg = $error['message'];
2499                                 break;
2500                         }
2501                 }
2502                 foreach ( $readyPipes as $pipe ) {
2503                         $block = fread( $pipe, 65536 );
2504                         $fd = $fds[(int)$pipe];
2505                         if ( $block === '' ) {
2506                                 // End of file
2507                                 fclose( $pipes[$fd] );
2508                                 unset( $pipes[$fd] );
2509                                 if ( !$pipes ) {
2510                                         break 2;
2511                                 }
2512                         } elseif ( $block === false ) {
2513                                 // Read error
2514                                 $logMsg = "Error reading from pipe";
2515                                 break 2;
2516                         } elseif ( $fd == 1 ) {
2517                                 // From stdout
2518                                 $outBuffer .= $block;
2519                         } elseif ( $fd == 3 ) {
2520                                 // From log FD
2521                                 $logBuffer .= $block;
2522                                 if ( strpos( $block, "\n" ) !== false ) {
2523                                         $lines = explode( "\n", $logBuffer );
2524                                         $logBuffer = array_pop( $lines );
2525                                         foreach ( $lines as $line ) {
2526                                                 wfDebugLog( 'exec', $line );
2527                                         }
2528                                 }
2529                         }
2530                 }
2531         }
2532
2533         foreach ( $pipes as $pipe ) {
2534                 fclose( $pipe );
2535         }
2536
2537         // Use the status previously collected if possible, since proc_get_status()
2538         // just calls waitpid() which will not return anything useful the second time.
2539         if ( $running ) {
2540                 $status = proc_get_status( $proc );
2541         }
2542
2543         if ( $logMsg !== false ) {
2544                 // Read/select error
2545                 $retval = -1;
2546                 proc_close( $proc );
2547         } elseif ( $status['signaled'] ) {
2548                 $logMsg = "Exited with signal {$status['termsig']}";
2549                 $retval = 128 + $status['termsig'];
2550                 proc_close( $proc );
2551         } else {
2552                 if ( $status['running'] ) {
2553                         $retval = proc_close( $proc );
2554                 } else {
2555                         $retval = $status['exitcode'];
2556                         proc_close( $proc );
2557                 }
2558                 if ( $retval == 127 ) {
2559                         $logMsg = "Possibly missing executable file";
2560                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2561                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2562                 }
2563         }
2564
2565         if ( $logMsg !== false ) {
2566                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2567         }
2568
2569         return $outBuffer;
2570 }
2571
2572 /**
2573  * Execute a shell command, returning both stdout and stderr. Convenience
2574  * function, as all the arguments to wfShellExec can become unwieldy.
2575  *
2576  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2577  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2578  *   or an array of unescaped arguments, in which case each value will be escaped
2579  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2580  * @param null|mixed &$retval Optional, will receive the program's exit code.
2581  *   (non-zero is usually failure)
2582  * @param array $environ Optional environment variables which should be
2583  *   added to the executed command environment.
2584  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2585  *   this overwrites the global wgMaxShell* limits.
2586  * @return string Collected stdout and stderr as a string
2587  */
2588 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = [], $limits = [] ) {
2589         return wfShellExec( $cmd, $retval, $environ, $limits,
2590                 [ 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ] );
2591 }
2592
2593 /**
2594  * Workaround for http://bugs.php.net/bug.php?id=45132
2595  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2596  */
2597 function wfInitShellLocale() {
2598         static $done = false;
2599         if ( $done ) {
2600                 return;
2601         }
2602         $done = true;
2603         global $wgShellLocale;
2604         putenv( "LC_CTYPE=$wgShellLocale" );
2605         setlocale( LC_CTYPE, $wgShellLocale );
2606 }
2607
2608 /**
2609  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2610  * Note that $parameters should be a flat array and an option with an argument
2611  * should consist of two consecutive items in the array (do not use "--option value").
2612  *
2613  * @param string $script MediaWiki cli script path
2614  * @param array $parameters Arguments and options to the script
2615  * @param array $options Associative array of options:
2616  *              'php': The path to the php executable
2617  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2618  * @return string
2619  */
2620 function wfShellWikiCmd( $script, array $parameters = [], array $options = [] ) {
2621         global $wgPhpCli;
2622         // Give site config file a chance to run the script in a wrapper.
2623         // The caller may likely want to call wfBasename() on $script.
2624         Hooks::run( 'wfShellWikiCmd', [ &$script, &$parameters, &$options ] );
2625         $cmd = isset( $options['php'] ) ? [ $options['php'] ] : [ $wgPhpCli ];
2626         if ( isset( $options['wrapper'] ) ) {
2627                 $cmd[] = $options['wrapper'];
2628         }
2629         $cmd[] = $script;
2630         // Escape each parameter for shell
2631         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
2632 }
2633
2634 /**
2635  * wfMerge attempts to merge differences between three texts.
2636  * Returns true for a clean merge and false for failure or a conflict.
2637  *
2638  * @param string $old
2639  * @param string $mine
2640  * @param string $yours
2641  * @param string $result
2642  * @return bool
2643  */
2644 function wfMerge( $old, $mine, $yours, &$result ) {
2645         global $wgDiff3;
2646
2647         # This check may also protect against code injection in
2648         # case of broken installations.
2649         MediaWiki\suppressWarnings();
2650         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2651         MediaWiki\restoreWarnings();
2652
2653         if ( !$haveDiff3 ) {
2654                 wfDebug( "diff3 not found\n" );
2655                 return false;
2656         }
2657
2658         # Make temporary files
2659         $td = wfTempDir();
2660         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2661         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2662         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2663
2664         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2665         #       a newline character. To avoid this, we normalize the trailing whitespace before
2666         #       creating the diff.
2667
2668         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2669         fclose( $oldtextFile );
2670         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2671         fclose( $mytextFile );
2672         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2673         fclose( $yourtextFile );
2674
2675         # Check for a conflict
2676         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
2677                 $oldtextName, $yourtextName );
2678         $handle = popen( $cmd, 'r' );
2679
2680         if ( fgets( $handle, 1024 ) ) {
2681                 $conflict = true;
2682         } else {
2683                 $conflict = false;
2684         }
2685         pclose( $handle );
2686
2687         # Merge differences
2688         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
2689                 $oldtextName, $yourtextName );
2690         $handle = popen( $cmd, 'r' );
2691         $result = '';
2692         do {
2693                 $data = fread( $handle, 8192 );
2694                 if ( strlen( $data ) == 0 ) {
2695                         break;
2696                 }
2697                 $result .= $data;
2698         } while ( true );
2699         pclose( $handle );
2700         unlink( $mytextName );
2701         unlink( $oldtextName );
2702         unlink( $yourtextName );
2703
2704         if ( $result === '' && $old !== '' && !$conflict ) {
2705                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2706                 $conflict = true;
2707         }
2708         return !$conflict;
2709 }
2710
2711 /**
2712  * Returns unified plain-text diff of two texts.
2713  * "Useful" for machine processing of diffs.
2714  *
2715  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
2716  *
2717  * @param string $before The text before the changes.
2718  * @param string $after The text after the changes.
2719  * @param string $params Command-line options for the diff command.
2720  * @return string Unified diff of $before and $after
2721  */
2722 function wfDiff( $before, $after, $params = '-u' ) {
2723         if ( $before == $after ) {
2724                 return '';
2725         }
2726
2727         global $wgDiff;
2728         MediaWiki\suppressWarnings();
2729         $haveDiff = $wgDiff && file_exists( $wgDiff );
2730         MediaWiki\restoreWarnings();
2731
2732         # This check may also protect against code injection in
2733         # case of broken installations.
2734         if ( !$haveDiff ) {
2735                 wfDebug( "diff executable not found\n" );
2736                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2737                 $format = new UnifiedDiffFormatter();
2738                 return $format->format( $diffs );
2739         }
2740
2741         # Make temporary files
2742         $td = wfTempDir();
2743         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2744         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2745
2746         fwrite( $oldtextFile, $before );
2747         fclose( $oldtextFile );
2748         fwrite( $newtextFile, $after );
2749         fclose( $newtextFile );
2750
2751         // Get the diff of the two files
2752         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2753
2754         $h = popen( $cmd, 'r' );
2755         if ( !$h ) {
2756                 unlink( $oldtextName );
2757                 unlink( $newtextName );
2758                 throw new Exception( __METHOD__ . '(): popen() failed' );
2759         }
2760
2761         $diff = '';
2762
2763         do {
2764                 $data = fread( $h, 8192 );
2765                 if ( strlen( $data ) == 0 ) {
2766                         break;
2767                 }
2768                 $diff .= $data;
2769         } while ( true );
2770
2771         // Clean up
2772         pclose( $h );
2773         unlink( $oldtextName );
2774         unlink( $newtextName );
2775
2776         // Kill the --- and +++ lines. They're not useful.
2777         $diff_lines = explode( "\n", $diff );
2778         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
2779                 unset( $diff_lines[0] );
2780         }
2781         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
2782                 unset( $diff_lines[1] );
2783         }
2784
2785         $diff = implode( "\n", $diff_lines );
2786
2787         return $diff;
2788 }
2789
2790 /**
2791  * This function works like "use VERSION" in Perl, the program will die with a
2792  * backtrace if the current version of PHP is less than the version provided
2793  *
2794  * This is useful for extensions which due to their nature are not kept in sync
2795  * with releases, and might depend on other versions of PHP than the main code
2796  *
2797  * Note: PHP might die due to parsing errors in some cases before it ever
2798  *       manages to call this function, such is life
2799  *
2800  * @see perldoc -f use
2801  *
2802  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2803  * @throws MWException
2804  */
2805 function wfUsePHP( $req_ver ) {
2806         $php_ver = PHP_VERSION;
2807
2808         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2809                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2810         }
2811 }
2812
2813 /**
2814  * This function works like "use VERSION" in Perl except it checks the version
2815  * of MediaWiki, the program will die with a backtrace if the current version
2816  * of MediaWiki is less than the version provided.
2817  *
2818  * This is useful for extensions which due to their nature are not kept in sync
2819  * with releases
2820  *
2821  * Note: Due to the behavior of PHP's version_compare() which is used in this
2822  * function, if you want to allow the 'wmf' development versions add a 'c' (or
2823  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
2824  * targeted version number. For example if you wanted to allow any variation
2825  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
2826  * not result in the same comparison due to the internal logic of
2827  * version_compare().
2828  *
2829  * @see perldoc -f use
2830  *
2831  * @deprecated since 1.26, use the "requires' property of extension.json
2832  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
2833  * @throws MWException
2834  */
2835 function wfUseMW( $req_ver ) {
2836         global $wgVersion;
2837
2838         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2839                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2840         }
2841 }
2842
2843 /**
2844  * Return the final portion of a pathname.
2845  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
2846  * http://bugs.php.net/bug.php?id=33898
2847  *
2848  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2849  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
2850  *
2851  * @param string $path
2852  * @param string $suffix String to remove if present
2853  * @return string
2854  */
2855 function wfBaseName( $path, $suffix = '' ) {
2856         if ( $suffix == '' ) {
2857                 $encSuffix = '';
2858         } else {
2859                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
2860         }
2861
2862         $matches = [];
2863         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2864                 return $matches[1];
2865         } else {
2866                 return '';
2867         }
2868 }
2869
2870 /**
2871  * Generate a relative path name to the given file.
2872  * May explode on non-matching case-insensitive paths,
2873  * funky symlinks, etc.
2874  *
2875  * @param string $path Absolute destination path including target filename
2876  * @param string $from Absolute source path, directory only
2877  * @return string
2878  */
2879 function wfRelativePath( $path, $from ) {
2880         // Normalize mixed input on Windows...
2881         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2882         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2883
2884         // Trim trailing slashes -- fix for drive root
2885         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2886         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2887
2888         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2889         $against = explode( DIRECTORY_SEPARATOR, $from );
2890
2891         if ( $pieces[0] !== $against[0] ) {
2892                 // Non-matching Windows drive letters?
2893                 // Return a full path.
2894                 return $path;
2895         }
2896
2897         // Trim off common prefix
2898         while ( count( $pieces ) && count( $against )
2899                 && $pieces[0] == $against[0] ) {
2900                 array_shift( $pieces );
2901                 array_shift( $against );
2902         }
2903
2904         // relative dots to bump us to the parent
2905         while ( count( $against ) ) {
2906                 array_unshift( $pieces, '..' );
2907                 array_shift( $against );
2908         }
2909
2910         array_push( $pieces, wfBaseName( $path ) );
2911
2912         return implode( DIRECTORY_SEPARATOR, $pieces );
2913 }
2914
2915 /**
2916  * Convert an arbitrarily-long digit string from one numeric base
2917  * to another, optionally zero-padding to a minimum column width.
2918  *
2919  * Supports base 2 through 36; digit values 10-36 are represented
2920  * as lowercase letters a-z. Input is case-insensitive.
2921  *
2922  * @deprecated 1.27 Use Wikimedia\base_convert() directly
2923  *
2924  * @param string $input Input number
2925  * @param int $sourceBase Base of the input number
2926  * @param int $destBase Desired base of the output
2927  * @param int $pad Minimum number of digits in the output (pad with zeroes)
2928  * @param bool $lowercase Whether to output in lowercase or uppercase
2929  * @param string $engine Either "gmp", "bcmath", or "php"
2930  * @return string|bool The output number as a string, or false on error
2931  */
2932 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
2933         $lowercase = true, $engine = 'auto'
2934 ) {
2935         return Wikimedia\base_convert( $input, $sourceBase, $destBase, $pad, $lowercase, $engine );
2936 }
2937
2938 /**
2939  * @deprecated since 1.27, PHP's session generation isn't used with
2940  *  MediaWiki\Session\SessionManager
2941  */
2942 function wfFixSessionID() {
2943         wfDeprecated( __FUNCTION__, '1.27' );
2944 }
2945
2946 /**
2947  * Reset the session id
2948  *
2949  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead
2950  * @since 1.22
2951  */
2952 function wfResetSessionID() {
2953         wfDeprecated( __FUNCTION__, '1.27' );
2954         $session = SessionManager::getGlobalSession();
2955         $delay = $session->delaySave();
2956
2957         $session->resetId();
2958
2959         // Make sure a session is started, since that's what the old
2960         // wfResetSessionID() did.
2961         if ( session_id() !== $session->getId() ) {
2962                 wfSetupSession( $session->getId() );
2963         }
2964
2965         ScopedCallback::consume( $delay );
2966 }
2967
2968 /**
2969  * Initialise php session
2970  *
2971  * @deprecated since 1.27, use MediaWiki\Session\SessionManager instead.
2972  *  Generally, "using" SessionManager will be calling ->getSessionById() or
2973  *  ::getGlobalSession() (depending on whether you were passing $sessionId
2974  *  here), then calling $session->persist().
2975  * @param bool|string $sessionId
2976  */
2977 function wfSetupSession( $sessionId = false ) {
2978         wfDeprecated( __FUNCTION__, '1.27' );
2979
2980         if ( $sessionId ) {
2981                 session_id( $sessionId );
2982         }
2983
2984         $session = SessionManager::getGlobalSession();
2985         $session->persist();
2986
2987         if ( session_id() !== $session->getId() ) {
2988                 session_id( $session->getId() );
2989         }
2990         MediaWiki\quietCall( 'session_start' );
2991 }
2992
2993 /**
2994  * Get an object from the precompiled serialized directory
2995  *
2996  * @param string $name
2997  * @return mixed The variable on success, false on failure
2998  */
2999 function wfGetPrecompiledData( $name ) {
3000         global $IP;
3001
3002         $file = "$IP/serialized/$name";
3003         if ( file_exists( $file ) ) {
3004                 $blob = file_get_contents( $file );
3005                 if ( $blob ) {
3006                         return unserialize( $blob );
3007                 }
3008         }
3009         return false;
3010 }
3011
3012 /**
3013  * Make a cache key for the local wiki.
3014  *
3015  * @param string $args,...
3016  * @return string
3017  */
3018 function wfMemcKey( /*...*/ ) {
3019         return call_user_func_array(
3020                 [ ObjectCache::getLocalClusterInstance(), 'makeKey' ],
3021                 func_get_args()
3022         );
3023 }
3024
3025 /**
3026  * Make a cache key for a foreign DB.
3027  *
3028  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3029  *
3030  * @param string $db
3031  * @param string $prefix
3032  * @param string $args,...
3033  * @return string
3034  */
3035 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3036         $args = array_slice( func_get_args(), 2 );
3037         $keyspace = $prefix ? "$db-$prefix" : $db;
3038         return call_user_func_array(
3039                 [ ObjectCache::getLocalClusterInstance(), 'makeKeyInternal' ],
3040                 [ $keyspace, $args ]
3041         );
3042 }
3043
3044 /**
3045  * Make a cache key with database-agnostic prefix.
3046  *
3047  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3048  * instead. Must have a prefix as otherwise keys that use a database name
3049  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3050  *
3051  * @since 1.26
3052  * @param string $args,...
3053  * @return string
3054  */
3055 function wfGlobalCacheKey( /*...*/ ) {
3056         return call_user_func_array(
3057                 [ ObjectCache::getLocalClusterInstance(), 'makeGlobalKey' ],
3058                 func_get_args()
3059         );
3060 }
3061
3062 /**
3063  * Get an ASCII string identifying this wiki
3064  * This is used as a prefix in memcached keys
3065  *
3066  * @return string
3067  */
3068 function wfWikiID() {
3069         global $wgDBprefix, $wgDBname;
3070         if ( $wgDBprefix ) {
3071                 return "$wgDBname-$wgDBprefix";
3072         } else {
3073                 return $wgDBname;
3074         }
3075 }
3076
3077 /**
3078  * Split a wiki ID into DB name and table prefix
3079  *
3080  * @param string $wiki
3081  *
3082  * @return array
3083  */
3084 function wfSplitWikiID( $wiki ) {
3085         $bits = explode( '-', $wiki, 2 );
3086         if ( count( $bits ) < 2 ) {
3087                 $bits[] = '';
3088         }
3089         return $bits;
3090 }
3091
3092 /**
3093  * Get a Database object.
3094  *
3095  * @param int $db Index of the connection to get. May be DB_MASTER for the
3096  *            master (for write queries), DB_SLAVE for potentially lagged read
3097  *            queries, or an integer >= 0 for a particular server.
3098  *
3099  * @param string|string[] $groups Query groups. An array of group names that this query
3100  *                belongs to. May contain a single string if the query is only
3101  *                in one group.
3102  *
3103  * @param string|bool $wiki The wiki ID, or false for the current wiki
3104  *
3105  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3106  * will always return the same object, unless the underlying connection or load
3107  * balancer is manually destroyed.
3108  *
3109  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3110  * updater to ensure that a proper database is being updated.
3111  *
3112  * @todo Replace calls to wfGetDB with calls to LoadBalancer::getConnection()
3113  *       on an injected instance of LoadBalancer.
3114  *
3115  * @return DatabaseBase
3116  */
3117 function wfGetDB( $db, $groups = [], $wiki = false ) {
3118         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3119 }
3120
3121 /**
3122  * Get a load balancer object.
3123  *
3124  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancer()
3125  *              or MediaWikiServices::getDBLoadBalancerFactory() instead.
3126  *
3127  * @param string|bool $wiki Wiki ID, or false for the current wiki
3128  * @return LoadBalancer
3129  */
3130 function wfGetLB( $wiki = false ) {
3131         if ( $wiki === false ) {
3132                 return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancer();
3133         } else {
3134                 $factory = \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3135                 return $factory->getMainLB( $wiki );
3136         }
3137 }
3138
3139 /**
3140  * Get the load balancer factory object
3141  *
3142  * @deprecated since 1.27, use MediaWikiServices::getDBLoadBalancerFactory() instead.
3143  *
3144  * @return LBFactory
3145  */
3146 function wfGetLBFactory() {
3147         return \MediaWiki\MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
3148 }
3149
3150 /**
3151  * Find a file.
3152  * Shortcut for RepoGroup::singleton()->findFile()
3153  *
3154  * @param string $title String or Title object
3155  * @param array $options Associative array of options (see RepoGroup::findFile)
3156  * @return File|bool File, or false if the file does not exist
3157  */
3158 function wfFindFile( $title, $options = [] ) {
3159         return RepoGroup::singleton()->findFile( $title, $options );
3160 }
3161
3162 /**
3163  * Get an object referring to a locally registered file.
3164  * Returns a valid placeholder object if the file does not exist.
3165  *
3166  * @param Title|string $title
3167  * @return LocalFile|null A File, or null if passed an invalid Title
3168  */
3169 function wfLocalFile( $title ) {
3170         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3171 }
3172
3173 /**
3174  * Should low-performance queries be disabled?
3175  *
3176  * @return bool
3177  * @codeCoverageIgnore
3178  */
3179 function wfQueriesMustScale() {
3180         global $wgMiserMode;
3181         return $wgMiserMode
3182                 || ( SiteStats::pages() > 100000
3183                 && SiteStats::edits() > 1000000
3184                 && SiteStats::users() > 10000 );
3185 }
3186
3187 /**
3188  * Get the path to a specified script file, respecting file
3189  * extensions; this is a wrapper around $wgScriptPath etc.
3190  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3191  *
3192  * @param string $script Script filename, sans extension
3193  * @return string
3194  */
3195 function wfScript( $script = 'index' ) {
3196         global $wgScriptPath, $wgScript, $wgLoadScript;
3197         if ( $script === 'index' ) {
3198                 return $wgScript;
3199         } elseif ( $script === 'load' ) {
3200                 return $wgLoadScript;
3201         } else {
3202                 return "{$wgScriptPath}/{$script}.php";
3203         }
3204 }
3205
3206 /**
3207  * Get the script URL.
3208  *
3209  * @return string Script URL
3210  */
3211 function wfGetScriptUrl() {
3212         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3213                 /* as it was called, minus the query string.
3214                  *
3215                  * Some sites use Apache rewrite rules to handle subdomains,
3216                  * and have PHP set up in a weird way that causes PHP_SELF
3217                  * to contain the rewritten URL instead of the one that the
3218                  * outside world sees.
3219                  *
3220                  * If in this mode, use SCRIPT_URL instead, which mod_rewrite
3221                  * provides containing the "before" URL.
3222                  */
3223                 return $_SERVER['SCRIPT_NAME'];
3224         } else {
3225                 return $_SERVER['URL'];
3226         }
3227 }
3228
3229 /**
3230  * Convenience function converts boolean values into "true"
3231  * or "false" (string) values
3232  *
3233  * @param bool $value
3234  * @return string
3235  */
3236 function wfBoolToStr( $value ) {
3237         return $value ? 'true' : 'false';
3238 }
3239
3240 /**
3241  * Get a platform-independent path to the null file, e.g. /dev/null
3242  *
3243  * @return string
3244  */
3245 function wfGetNull() {
3246         return wfIsWindows() ? 'NUL' : '/dev/null';
3247 }
3248
3249 /**
3250  * Waits for the slaves to catch up to the master position
3251  *
3252  * Use this when updating very large numbers of rows, as in maintenance scripts,
3253  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3254  *
3255  * By default this waits on the main DB cluster of the current wiki.
3256  * If $cluster is set to "*" it will wait on all DB clusters, including
3257  * external ones. If the lag being waiting on is caused by the code that
3258  * does this check, it makes since to use $ifWritesSince, particularly if
3259  * cluster is "*", to avoid excess overhead.
3260  *
3261  * Never call this function after a big DB write that is still in a transaction.
3262  * This only makes sense after the possible lag inducing changes were committed.
3263  *
3264  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3265  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3266  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3267  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3268  * @return bool Success (able to connect and no timeouts reached)
3269  * @deprecated since 1.27 Use LBFactory::waitForReplication
3270  */
3271 function wfWaitForSlaves(
3272         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3273 ) {
3274         if ( $timeout === null ) {
3275                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3276         }
3277
3278         if ( $cluster === '*' ) {
3279                 $cluster = false;
3280                 $wiki = false;
3281         } elseif ( $wiki === false ) {
3282                 $wiki = wfWikiID();
3283         }
3284
3285         try {
3286                 wfGetLBFactory()->waitForReplication( [
3287                         'wiki' => $wiki,
3288                         'cluster' => $cluster,
3289                         'timeout' => $timeout,
3290                         // B/C: first argument used to be "max seconds of lag"; ignore such values
3291                         'ifWritesSince' => ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null
3292                 ] );
3293         } catch ( DBReplicationWaitError $e ) {
3294                 return false;
3295         }
3296
3297         return true;
3298 }
3299
3300 /**
3301  * Count down from $seconds to zero on the terminal, with a one-second pause
3302  * between showing each number. For use in command-line scripts.
3303  *
3304  * @codeCoverageIgnore
3305  * @param int $seconds
3306  */
3307 function wfCountDown( $seconds ) {
3308         for ( $i = $seconds; $i >= 0; $i-- ) {
3309                 if ( $i != $seconds ) {
3310                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3311                 }
3312                 echo $i;
3313                 flush();
3314                 if ( $i ) {
3315                         sleep( 1 );
3316                 }
3317         }
3318         echo "\n";
3319 }
3320
3321 /**
3322  * Replace all invalid characters with -
3323  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3324  * By default, $wgIllegalFileChars = ':'
3325  *
3326  * @param string $name Filename to process
3327  * @return string
3328  */
3329 function wfStripIllegalFilenameChars( $name ) {
3330         global $wgIllegalFileChars;
3331         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3332         $name = wfBaseName( $name );
3333         $name = preg_replace(
3334                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3335                 '-',
3336                 $name
3337         );
3338         return $name;
3339 }
3340
3341 /**
3342  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3343  *
3344  * @return int Resulting value of the memory limit.
3345  */
3346 function wfMemoryLimit() {
3347         global $wgMemoryLimit;
3348         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3349         if ( $memlimit != -1 ) {
3350                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3351                 if ( $conflimit == -1 ) {
3352                         wfDebug( "Removing PHP's memory limit\n" );
3353                         MediaWiki\suppressWarnings();
3354                         ini_set( 'memory_limit', $conflimit );
3355                         MediaWiki\restoreWarnings();
3356                         return $conflimit;
3357                 } elseif ( $conflimit > $memlimit ) {
3358                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3359                         MediaWiki\suppressWarnings();
3360                         ini_set( 'memory_limit', $conflimit );
3361                         MediaWiki\restoreWarnings();
3362                         return $conflimit;
3363                 }
3364         }
3365         return $memlimit;
3366 }
3367
3368 /**
3369  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3370  *
3371  * @return int Prior time limit
3372  * @since 1.26
3373  */
3374 function wfTransactionalTimeLimit() {
3375         global $wgTransactionalTimeLimit;
3376
3377         $timeLimit = ini_get( 'max_execution_time' );
3378         // Note that CLI scripts use 0
3379         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3380                 set_time_limit( $wgTransactionalTimeLimit );
3381         }
3382
3383         ignore_user_abort( true ); // ignore client disconnects
3384
3385         return $timeLimit;
3386 }
3387
3388 /**
3389  * Converts shorthand byte notation to integer form
3390  *
3391  * @param string $string
3392  * @param int $default Returned if $string is empty
3393  * @return int
3394  */
3395 function wfShorthandToInteger( $string = '', $default = -1 ) {
3396         $string = trim( $string );
3397         if ( $string === '' ) {
3398                 return $default;
3399         }
3400         $last = $string[strlen( $string ) - 1];
3401         $val = intval( $string );
3402         switch ( $last ) {
3403                 case 'g':
3404                 case 'G':
3405                         $val *= 1024;
3406                         // break intentionally missing
3407                 case 'm':
3408                 case 'M':
3409                         $val *= 1024;
3410                         // break intentionally missing
3411                 case 'k':
3412                 case 'K':
3413                         $val *= 1024;
3414         }
3415
3416         return $val;
3417 }
3418
3419 /**
3420  * Get the normalised IETF language tag
3421  * See unit test for examples.
3422  *
3423  * @param string $code The language code.
3424  * @return string The language code which complying with BCP 47 standards.
3425  */
3426 function wfBCP47( $code ) {
3427         $codeSegment = explode( '-', $code );
3428         $codeBCP = [];
3429         foreach ( $codeSegment as $segNo => $seg ) {
3430                 // when previous segment is x, it is a private segment and should be lc
3431                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3432                         $codeBCP[$segNo] = strtolower( $seg );
3433                 // ISO 3166 country code
3434                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3435                         $codeBCP[$segNo] = strtoupper( $seg );
3436                 // ISO 15924 script code
3437                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3438                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3439                 // Use lowercase for other cases
3440                 } else {
3441                         $codeBCP[$segNo] = strtolower( $seg );
3442                 }
3443         }
3444         $langCode = implode( '-', $codeBCP );
3445         return $langCode;
3446 }
3447
3448 /**
3449  * Get a specific cache object.
3450  *
3451  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3452  * @return BagOStuff
3453  */
3454 function wfGetCache( $cacheType ) {
3455         return ObjectCache::getInstance( $cacheType );
3456 }
3457
3458 /**
3459  * Get the main cache object
3460  *
3461  * @return BagOStuff
3462  */
3463 function wfGetMainCache() {
3464         global $wgMainCacheType;
3465         return ObjectCache::getInstance( $wgMainCacheType );
3466 }
3467
3468 /**
3469  * Get the cache object used by the message cache
3470  *
3471  * @return BagOStuff
3472  */
3473 function wfGetMessageCacheStorage() {
3474         global $wgMessageCacheType;
3475         return ObjectCache::getInstance( $wgMessageCacheType );
3476 }
3477
3478 /**
3479  * Get the cache object used by the parser cache
3480  *
3481  * @return BagOStuff
3482  */
3483 function wfGetParserCacheStorage() {
3484         global $wgParserCacheType;
3485         return ObjectCache::getInstance( $wgParserCacheType );
3486 }
3487
3488 /**
3489  * Call hook functions defined in $wgHooks
3490  *
3491  * @param string $event Event name
3492  * @param array $args Parameters passed to hook functions
3493  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3494  *
3495  * @return bool True if no handler aborted the hook
3496  * @deprecated 1.25 - use Hooks::run
3497  */
3498 function wfRunHooks( $event, array $args = [], $deprecatedVersion = null ) {
3499         return Hooks::run( $event, $args, $deprecatedVersion );
3500 }
3501
3502 /**
3503  * Wrapper around php's unpack.
3504  *
3505  * @param string $format The format string (See php's docs)
3506  * @param string $data A binary string of binary data
3507  * @param int|bool $length The minimum length of $data or false. This is to
3508  *      prevent reading beyond the end of $data. false to disable the check.
3509  *
3510  * Also be careful when using this function to read unsigned 32 bit integer
3511  * because php might make it negative.
3512  *
3513  * @throws MWException If $data not long enough, or if unpack fails
3514  * @return array Associative array of the extracted data
3515  */
3516 function wfUnpack( $format, $data, $length = false ) {
3517         if ( $length !== false ) {
3518                 $realLen = strlen( $data );
3519                 if ( $realLen < $length ) {
3520                         throw new MWException( "Tried to use wfUnpack on a "
3521                                 . "string of length $realLen, but needed one "
3522                                 . "of at least length $length."
3523                         );
3524                 }
3525         }
3526
3527         MediaWiki\suppressWarnings();
3528         $result = unpack( $format, $data );
3529         MediaWiki\restoreWarnings();
3530
3531         if ( $result === false ) {
3532                 // If it cannot extract the packed data.
3533                 throw new MWException( "unpack could not unpack binary data" );
3534         }
3535         return $result;
3536 }
3537
3538 /**
3539  * Determine if an image exists on the 'bad image list'.
3540  *
3541  * The format of MediaWiki:Bad_image_list is as follows:
3542  *    * Only list items (lines starting with "*") are considered
3543  *    * The first link on a line must be a link to a bad image
3544  *    * Any subsequent links on the same line are considered to be exceptions,
3545  *      i.e. articles where the image may occur inline.
3546  *
3547  * @param string $name The image name to check
3548  * @param Title|bool $contextTitle The page on which the image occurs, if known
3549  * @param string $blacklist Wikitext of a file blacklist
3550  * @return bool
3551  */
3552 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3553         # Handle redirects; callers almost always hit wfFindFile() anyway,
3554         # so just use that method because it has a fast process cache.
3555         $file = wfFindFile( $name ); // get the final name
3556         $name = $file ? $file->getTitle()->getDBkey() : $name;
3557
3558         # Run the extension hook
3559         $bad = false;
3560         if ( !Hooks::run( 'BadImage', [ $name, &$bad ] ) ) {
3561                 return $bad;
3562         }
3563
3564         $cache = ObjectCache::getLocalServerInstance( 'hash' );
3565         $key = wfMemcKey( 'bad-image-list', ( $blacklist === null ) ? 'default' : md5( $blacklist ) );
3566         $badImages = $cache->get( $key );
3567
3568         if ( $badImages === false ) { // cache miss
3569                 if ( $blacklist === null ) {
3570                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3571                 }
3572                 # Build the list now
3573                 $badImages = [];
3574                 $lines = explode( "\n", $blacklist );
3575                 foreach ( $lines as $line ) {
3576                         # List items only
3577                         if ( substr( $line, 0, 1 ) !== '*' ) {
3578                                 continue;
3579                         }
3580
3581                         # Find all links
3582                         $m = [];
3583                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3584                                 continue;
3585                         }
3586
3587                         $exceptions = [];
3588                         $imageDBkey = false;
3589                         foreach ( $m[1] as $i => $titleText ) {
3590                                 $title = Title::newFromText( $titleText );
3591                                 if ( !is_null( $title ) ) {
3592                                         if ( $i == 0 ) {
3593                                                 $imageDBkey = $title->getDBkey();
3594                                         } else {
3595                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3596                                         }
3597                                 }
3598                         }
3599
3600                         if ( $imageDBkey !== false ) {
3601                                 $badImages[$imageDBkey] = $exceptions;
3602                         }
3603                 }
3604                 $cache->set( $key, $badImages, 60 );
3605         }
3606
3607         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3608         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3609
3610         return $bad;
3611 }
3612
3613 /**
3614  * Determine whether the client at a given source IP is likely to be able to
3615  * access the wiki via HTTPS.
3616  *
3617  * @param string $ip The IPv4/6 address in the normal human-readable form
3618  * @return bool
3619  */
3620 function wfCanIPUseHTTPS( $ip ) {
3621         $canDo = true;
3622         Hooks::run( 'CanIPUseHTTPS', [ $ip, &$canDo ] );
3623         return !!$canDo;
3624 }
3625
3626 /**
3627  * Determine input string is represents as infinity
3628  *
3629  * @param string $str The string to determine
3630  * @return bool
3631  * @since 1.25
3632  */
3633 function wfIsInfinity( $str ) {
3634         $infinityValues = [ 'infinite', 'indefinite', 'infinity', 'never' ];
3635         return in_array( $str, $infinityValues );
3636 }
3637
3638 /**
3639  * Returns true if these thumbnail parameters match one that MediaWiki
3640  * requests from file description pages and/or parser output.
3641  *
3642  * $params is considered non-standard if they involve a non-standard
3643  * width or any non-default parameters aside from width and page number.
3644  * The number of possible files with standard parameters is far less than
3645  * that of all combinations; rate-limiting for them can thus be more generious.
3646  *
3647  * @param File $file
3648  * @param array $params
3649  * @return bool
3650  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
3651  */
3652 function wfThumbIsStandard( File $file, array $params ) {
3653         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
3654
3655         $multipliers = [ 1 ];
3656         if ( $wgResponsiveImages ) {
3657                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
3658                 // @see Linker::processResponsiveImages
3659                 $multipliers[] = 1.5;
3660                 $multipliers[] = 2;
3661         }
3662
3663         $handler = $file->getHandler();
3664         if ( !$handler || !isset( $params['width'] ) ) {
3665                 return false;
3666         }
3667
3668         $basicParams = [];
3669         if ( isset( $params['page'] ) ) {
3670                 $basicParams['page'] = $params['page'];
3671         }
3672
3673         $thumbLimits = [];
3674         $imageLimits = [];
3675         // Expand limits to account for multipliers
3676         foreach ( $multipliers as $multiplier ) {
3677                 $thumbLimits = array_merge( $thumbLimits, array_map(
3678                         function ( $width ) use ( $multiplier ) {
3679                                 return round( $width * $multiplier );
3680                         }, $wgThumbLimits )
3681                 );
3682                 $imageLimits = array_merge( $imageLimits, array_map(
3683                         function ( $pair ) use ( $multiplier ) {
3684                                 return [
3685                                         round( $pair[0] * $multiplier ),
3686                                         round( $pair[1] * $multiplier ),
3687                                 ];
3688                         }, $wgImageLimits )
3689                 );
3690         }
3691
3692         // Check if the width matches one of $wgThumbLimits
3693         if ( in_array( $params['width'], $thumbLimits ) ) {
3694                 $normalParams = $basicParams + [ 'width' => $params['width'] ];
3695                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
3696                 $handler->normaliseParams( $file, $normalParams );
3697         } else {
3698                 // If not, then check if the width matchs one of $wgImageLimits
3699                 $match = false;
3700                 foreach ( $imageLimits as $pair ) {
3701                         $normalParams = $basicParams + [ 'width' => $pair[0], 'height' => $pair[1] ];
3702                         // Decide whether the thumbnail should be scaled on width or height.
3703                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
3704                         $handler->normaliseParams( $file, $normalParams );
3705                         // Check if this standard thumbnail size maps to the given width
3706                         if ( $normalParams['width'] == $params['width'] ) {
3707                                 $match = true;
3708                                 break;
3709                         }
3710                 }
3711                 if ( !$match ) {
3712                         return false; // not standard for description pages
3713                 }
3714         }
3715
3716         // Check that the given values for non-page, non-width, params are just defaults
3717         foreach ( $params as $key => $value ) {
3718                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
3719                         return false;
3720                 }
3721         }
3722
3723         return true;
3724 }
3725
3726 /**
3727  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
3728  *
3729  * Values that exist in both values will be combined with += (all values of the array
3730  * of $newValues will be added to the values of the array of $baseArray, while values,
3731  * that exists in both, the value of $baseArray will be used).
3732  *
3733  * @param array $baseArray The array where you want to add the values of $newValues to
3734  * @param array $newValues An array with new values
3735  * @return array The combined array
3736  * @since 1.26
3737  */
3738 function wfArrayPlus2d( array $baseArray, array $newValues ) {
3739         // First merge items that are in both arrays
3740         foreach ( $baseArray as $name => &$groupVal ) {
3741                 if ( isset( $newValues[$name] ) ) {
3742                         $groupVal += $newValues[$name];
3743                 }
3744         }
3745         // Now add items that didn't exist yet
3746         $baseArray += $newValues;
3747
3748         return $baseArray;
3749 }