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\StatsdClient;
  28 use Liuggio\StatsdClient\Sender\SocketSender;
  29 use MediaWiki\Logger\LoggerFactory;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.3.3 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 if ( !function_exists( 'mb_substr' ) ) {
  43         /**
  44          * @codeCoverageIgnore
  45          * @see Fallback::mb_substr
  46          * @return string
  47          */
  48         function mb_substr( $str, $start, $count = 'end' ) {
  49                 return Fallback::mb_substr( $str, $start, $count );
  50         }
  51
  52         /**
  53          * @codeCoverageIgnore
  54          * @see Fallback::mb_substr_split_unicode
  55          * @return int
  56          */
  57         function mb_substr_split_unicode( $str, $splitPos ) {
  58                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  59         }
  60 }
  61
  62 if ( !function_exists( 'mb_strlen' ) ) {
  63         /**
  64          * @codeCoverageIgnore
  65          * @see Fallback::mb_strlen
  66          * @return int
  67          */
  68         function mb_strlen( $str, $enc = '' ) {
  69                 return Fallback::mb_strlen( $str, $enc );
  70         }
  71 }
  72
  73 if ( !function_exists( 'mb_strpos' ) ) {
  74         /**
  75          * @codeCoverageIgnore
  76          * @see Fallback::mb_strpos
  77          * @return int
  78          */
  79         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  80                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  81         }
  82 }
  83
  84 if ( !function_exists( 'mb_strrpos' ) ) {
  85         /**
  86          * @codeCoverageIgnore
  87          * @see Fallback::mb_strrpos
  88          * @return int
  89          */
  90         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  91                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  92         }
  93 }
  94
  95 // gzdecode function only exists in PHP >= 5.4.0
  96 // http://php.net/gzdecode
  97 if ( !function_exists( 'gzdecode' ) ) {
  98         /**
  99          * @codeCoverageIgnore
 100          * @param string $data
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107
 108 // hash_equals function only exists in PHP >= 5.6.0
 109 // http://php.net/hash_equals
 110 if ( !function_exists( 'hash_equals' ) ) {
 111         /**
 112          * Check whether a user-provided string is equal to a fixed-length secret string
 113          * without revealing bytes of the secret string through timing differences.
 114          *
 115          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 116          * function in C) is to compare corresponding bytes and stop at the first difference,
 117          * which would take longer for a partial match than for a complete mismatch. This
 118          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 119          * and the other may come from an attacker. Statistical analysis of timing measurements
 120          * over many requests may allow the attacker to guess the string's bytes one at a time
 121          * (and check his guesses) even if the timing differences are extremely small.
 122          *
 123          * When making such a security-sensitive comparison, it is essential that the sequence
 124          * in which instructions are executed and memory locations are accessed not depend on
 125          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 126          * the inevitable leakage of the string's length. That is generally known anyway as
 127          * a chararacteristic of the hash function used to compute the secret value.
 128          *
 129          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 130          *
 131          * @codeCoverageIgnore
 132          * @param string $known_string Fixed-length secret string to compare against
 133          * @param string $user_string User-provided string
 134          * @return bool True if the strings are the same, false otherwise
 135          */
 136         function hash_equals( $known_string, $user_string ) {
 137                 // Strict type checking as in PHP's native implementation
 138                 if ( !is_string( $known_string ) ) {
 139                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 140                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 141
 142                         return false;
 143                 }
 144
 145                 if ( !is_string( $user_string ) ) {
 146                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 147                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 148
 149                         return false;
 150                 }
 151
 152                 $known_string_len = strlen( $known_string );
 153                 if ( $known_string_len !== strlen( $user_string ) ) {
 154                         return false;
 155                 }
 156
 157                 $result = 0;
 158                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 159                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 160                 }
 161
 162                 return ( $result === 0 );
 163         }
 164 }
 165 /// @endcond
 166
 167 /**
 168  * Load an extension
 169  *
 170  * This queues an extension to be loaded through
 171  * the ExtensionRegistry system.
 172  *
 173  * @param string $ext Name of the extension to load
 174  * @param string|null $path Absolute path of where to find the extension.json file
 175  */
 176 function wfLoadExtension( $ext, $path = null ) {
 177         if ( !$path ) {
 178                 global $wgExtensionDirectory;
 179                 $path = "$wgExtensionDirectory/$ext/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->queue( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  */
 196 function wfLoadExtensions( array $exts ) {
 197         global $wgExtensionDirectory;
 198         $registry = ExtensionRegistry::getInstance();
 199         foreach ( $exts as $ext ) {
 200                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 201         }
 202 }
 203
 204 /**
 205  * Load a skin
 206  *
 207  * @see wfLoadExtension
 208  * @param string $skin Name of the extension to load
 209  * @param string|null $path Absolute path of where to find the skin.json file
 210  */
 211 function wfLoadSkin( $skin, $path = null ) {
 212         if ( !$path ) {
 213                 global $wgStyleDirectory;
 214                 $path = "$wgStyleDirectory/$skin/skin.json";
 215         }
 216         ExtensionRegistry::getInstance()->queue( $path );
 217 }
 218
 219 /**
 220  * Load multiple skins at once
 221  *
 222  * @see wfLoadExtensions
 223  * @param string[] $skins Array of extension names to load
 224  */
 225 function wfLoadSkins( array $skins ) {
 226         global $wgStyleDirectory;
 227         $registry = ExtensionRegistry::getInstance();
 228         foreach ( $skins as $skin ) {
 229                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 230         }
 231 }
 232
 233 /**
 234  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 235  * @param array $a
 236  * @param array $b
 237  * @return array
 238  */
 239 function wfArrayDiff2( $a, $b ) {
 240         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 241 }
 242
 243 /**
 244  * @param array|string $a
 245  * @param array|string $b
 246  * @return int
 247  */
 248 function wfArrayDiff2_cmp( $a, $b ) {
 249         if ( is_string( $a ) && is_string( $b ) ) {
 250                 return strcmp( $a, $b );
 251         } elseif ( count( $a ) !== count( $b ) ) {
 252                 return count( $a ) < count( $b ) ? -1 : 1;
 253         } else {
 254                 reset( $a );
 255                 reset( $b );
 256                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 257                         $cmp = strcmp( $valueA, $valueB );
 258                         if ( $cmp !== 0 ) {
 259                                 return $cmp;
 260                         }
 261                 }
 262                 return 0;
 263         }
 264 }
 265
 266 /**
 267  * Appends to second array if $value differs from that in $default
 268  *
 269  * @param string|int $key
 270  * @param mixed $value
 271  * @param mixed $default
 272  * @param array $changed Array to alter
 273  * @throws MWException
 274  */
 275 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 276         if ( is_null( $changed ) ) {
 277                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 278         }
 279         if ( $default[$key] !== $value ) {
 280                 $changed[$key] = $value;
 281         }
 282 }
 283
 284 /**
 285  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 286  * e.g.
 287  *      wfMergeErrorArrays(
 288  *              array( array( 'x' ) ),
 289  *              array( array( 'x', '2' ) ),
 290  *              array( array( 'x' ) ),
 291  *              array( array( 'y' ) )
 292  *      );
 293  * returns:
 294  *              array(
 295  *              array( 'x', '2' ),
 296  *              array( 'x' ),
 297  *              array( 'y' )
 298  *      )
 299  *
 300  * @param array $array1,...
 301  * @return array
 302  */
 303 function wfMergeErrorArrays( /*...*/ ) {
 304         $args = func_get_args();
 305         $out = array();
 306         foreach ( $args as $errors ) {
 307                 foreach ( $errors as $params ) {
 308                         # @todo FIXME: Sometimes get nested arrays for $params,
 309                         # which leads to E_NOTICEs
 310                         $spec = implode( "\t", $params );
 311                         $out[$spec] = $params;
 312                 }
 313         }
 314         return array_values( $out );
 315 }
 316
 317 /**
 318  * Insert array into another array after the specified *KEY*
 319  *
 320  * @param array $array The array.
 321  * @param array $insert The array to insert.
 322  * @param mixed $after The key to insert after
 323  * @return array
 324  */
 325 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 326         // Find the offset of the element to insert after.
 327         $keys = array_keys( $array );
 328         $offsetByKey = array_flip( $keys );
 329
 330         $offset = $offsetByKey[$after];
 331
 332         // Insert at the specified offset
 333         $before = array_slice( $array, 0, $offset + 1, true );
 334         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 335
 336         $output = $before + $insert + $after;
 337
 338         return $output;
 339 }
 340
 341 /**
 342  * Recursively converts the parameter (an object) to an array with the same data
 343  *
 344  * @param object|array $objOrArray
 345  * @param bool $recursive
 346  * @return array
 347  */
 348 function wfObjectToArray( $objOrArray, $recursive = true ) {
 349         $array = array();
 350         if ( is_object( $objOrArray ) ) {
 351                 $objOrArray = get_object_vars( $objOrArray );
 352         }
 353         foreach ( $objOrArray as $key => $value ) {
 354                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 355                         $value = wfObjectToArray( $value );
 356                 }
 357
 358                 $array[$key] = $value;
 359         }
 360
 361         return $array;
 362 }
 363
 364 /**
 365  * Get a random decimal value between 0 and 1, in a way
 366  * not likely to give duplicate values for any realistic
 367  * number of articles.
 368  *
 369  * @return string
 370  */
 371 function wfRandom() {
 372         # The maximum random value is "only" 2^31-1, so get two random
 373         # values to reduce the chance of dupes
 374         $max = mt_getrandmax() + 1;
 375         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 376
 377         return $rand;
 378 }
 379
 380 /**
 381  * Get a random string containing a number of pseudo-random hex
 382  * characters.
 383  * @note This is not secure, if you are trying to generate some sort
 384  *       of token please use MWCryptRand instead.
 385  *
 386  * @param int $length The length of the string to generate
 387  * @return string
 388  * @since 1.20
 389  */
 390 function wfRandomString( $length = 32 ) {
 391         $str = '';
 392         for ( $n = 0; $n < $length; $n += 7 ) {
 393                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 394         }
 395         return substr( $str, 0, $length );
 396 }
 397
 398 /**
 399  * We want some things to be included as literal characters in our title URLs
 400  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 401  * all of the following should be safe:
 402  *
 403  * ;:@&=$-_.+!*'(),
 404  *
 405  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 406  * character which should not be encoded. More importantly, google chrome
 407  * always converts %7E back to ~, and converting it in this function can
 408  * cause a redirect loop (T105265).
 409  *
 410  * But + is not safe because it's used to indicate a space; &= are only safe in
 411  * paths and not in queries (and we don't distinguish here); ' seems kind of
 412  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 413  * is reserved, we don't care.  So the list we unescape is:
 414  *
 415  * ;:@$!*(),/~
 416  *
 417  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 418  * so no fancy : for IIS7.
 419  *
 420  * %2F in the page titles seems to fatally break for some reason.
 421  *
 422  * @param string $s
 423  * @return string
 424  */
 425 function wfUrlencode( $s ) {
 426         static $needle;
 427
 428         if ( is_null( $s ) ) {
 429                 $needle = null;
 430                 return '';
 431         }
 432
 433         if ( is_null( $needle ) ) {
 434                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 435                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 436                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 437                 ) {
 438                         $needle[] = '%3A';
 439                 }
 440         }
 441
 442         $s = urlencode( $s );
 443         $s = str_ireplace(
 444                 $needle,
 445                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 446                 $s
 447         );
 448
 449         return $s;
 450 }
 451
 452 /**
 453  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 454  * "days=7&limit=100". Options in the first array override options in the second.
 455  * Options set to null or false will not be output.
 456  *
 457  * @param array $array1 ( String|Array )
 458  * @param array $array2 ( String|Array )
 459  * @param string $prefix
 460  * @return string
 461  */
 462 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 463         if ( !is_null( $array2 ) ) {
 464                 $array1 = $array1 + $array2;
 465         }
 466
 467         $cgi = '';
 468         foreach ( $array1 as $key => $value ) {
 469                 if ( !is_null( $value ) && $value !== false ) {
 470                         if ( $cgi != '' ) {
 471                                 $cgi .= '&';
 472                         }
 473                         if ( $prefix !== '' ) {
 474                                 $key = $prefix . "[$key]";
 475                         }
 476                         if ( is_array( $value ) ) {
 477                                 $firstTime = true;
 478                                 foreach ( $value as $k => $v ) {
 479                                         $cgi .= $firstTime ? '' : '&';
 480                                         if ( is_array( $v ) ) {
 481                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 482                                         } else {
 483                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 484                                         }
 485                                         $firstTime = false;
 486                                 }
 487                         } else {
 488                                 if ( is_object( $value ) ) {
 489                                         $value = $value->__toString();
 490                                 }
 491                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 492                         }
 493                 }
 494         }
 495         return $cgi;
 496 }
 497
 498 /**
 499  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 500  * its argument and returns the same string in array form.  This allows compatibility
 501  * with legacy functions that accept raw query strings instead of nice
 502  * arrays.  Of course, keys and values are urldecode()d.
 503  *
 504  * @param string $query Query string
 505  * @return string[] Array version of input
 506  */
 507 function wfCgiToArray( $query ) {
 508         if ( isset( $query[0] ) && $query[0] == '?' ) {
 509                 $query = substr( $query, 1 );
 510         }
 511         $bits = explode( '&', $query );
 512         $ret = array();
 513         foreach ( $bits as $bit ) {
 514                 if ( $bit === '' ) {
 515                         continue;
 516                 }
 517                 if ( strpos( $bit, '=' ) === false ) {
 518                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 519                         $key = $bit;
 520                         $value = '';
 521                 } else {
 522                         list( $key, $value ) = explode( '=', $bit );
 523                 }
 524                 $key = urldecode( $key );
 525                 $value = urldecode( $value );
 526                 if ( strpos( $key, '[' ) !== false ) {
 527                         $keys = array_reverse( explode( '[', $key ) );
 528                         $key = array_pop( $keys );
 529                         $temp = $value;
 530                         foreach ( $keys as $k ) {
 531                                 $k = substr( $k, 0, -1 );
 532                                 $temp = array( $k => $temp );
 533                         }
 534                         if ( isset( $ret[$key] ) ) {
 535                                 $ret[$key] = array_merge( $ret[$key], $temp );
 536                         } else {
 537                                 $ret[$key] = $temp;
 538                         }
 539                 } else {
 540                         $ret[$key] = $value;
 541                 }
 542         }
 543         return $ret;
 544 }
 545
 546 /**
 547  * Append a query string to an existing URL, which may or may not already
 548  * have query string parameters already. If so, they will be combined.
 549  *
 550  * @param string $url
 551  * @param string|string[] $query String or associative array
 552  * @return string
 553  */
 554 function wfAppendQuery( $url, $query ) {
 555         if ( is_array( $query ) ) {
 556                 $query = wfArrayToCgi( $query );
 557         }
 558         if ( $query != '' ) {
 559                 if ( false === strpos( $url, '?' ) ) {
 560                         $url .= '?';
 561                 } else {
 562                         $url .= '&';
 563                 }
 564                 $url .= $query;
 565         }
 566         return $url;
 567 }
 568
 569 /**
 570  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 571  * is correct.
 572  *
 573  * The meaning of the PROTO_* constants is as follows:
 574  * PROTO_HTTP: Output a URL starting with http://
 575  * PROTO_HTTPS: Output a URL starting with https://
 576  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 577  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 578  *    on which protocol was used for the current incoming request
 579  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 580  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 581  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 582  *
 583  * @todo this won't work with current-path-relative URLs
 584  * like "subdir/foo.html", etc.
 585  *
 586  * @param string $url Either fully-qualified or a local path + query
 587  * @param string $defaultProto One of the PROTO_* constants. Determines the
 588  *    protocol to use if $url or $wgServer is protocol-relative
 589  * @return string Fully-qualified URL, current-path-relative URL or false if
 590  *    no valid URL can be constructed
 591  */
 592 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 593         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 594                 $wgHttpsPort;
 595         if ( $defaultProto === PROTO_CANONICAL ) {
 596                 $serverUrl = $wgCanonicalServer;
 597         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 598                 // Make $wgInternalServer fall back to $wgServer if not set
 599                 $serverUrl = $wgInternalServer;
 600         } else {
 601                 $serverUrl = $wgServer;
 602                 if ( $defaultProto === PROTO_CURRENT ) {
 603                         $defaultProto = $wgRequest->getProtocol() . '://';
 604                 }
 605         }
 606
 607         // Analyze $serverUrl to obtain its protocol
 608         $bits = wfParseUrl( $serverUrl );
 609         $serverHasProto = $bits && $bits['scheme'] != '';
 610
 611         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 612                 if ( $serverHasProto ) {
 613                         $defaultProto = $bits['scheme'] . '://';
 614                 } else {
 615                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 616                         // This really isn't supposed to happen. Fall back to HTTP in this
 617                         // ridiculous case.
 618                         $defaultProto = PROTO_HTTP;
 619                 }
 620         }
 621
 622         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 623
 624         if ( substr( $url, 0, 2 ) == '//' ) {
 625                 $url = $defaultProtoWithoutSlashes . $url;
 626         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 627                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 628                 // otherwise leave it alone.
 629                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 630         }
 631
 632         $bits = wfParseUrl( $url );
 633
 634         // ensure proper port for HTTPS arrives in URL
 635         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 636         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 637                 $bits['port'] = $wgHttpsPort;
 638         }
 639
 640         if ( $bits && isset( $bits['path'] ) ) {
 641                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 642                 return wfAssembleUrl( $bits );
 643         } elseif ( $bits ) {
 644                 # No path to expand
 645                 return $url;
 646         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 647                 # URL is a relative path
 648                 return wfRemoveDotSegments( $url );
 649         }
 650
 651         # Expanded URL is not valid.
 652         return false;
 653 }
 654
 655 /**
 656  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 657  * if you need to edit part of a URL and put it back together.
 658  *
 659  * This is the basic structure used (brackets contain keys for $urlParts):
 660  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 661  *
 662  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 663  *
 664  * @since 1.19
 665  * @param array $urlParts URL parts, as output from wfParseUrl
 666  * @return string URL assembled from its component parts
 667  */
 668 function wfAssembleUrl( $urlParts ) {
 669         $result = '';
 670
 671         if ( isset( $urlParts['delimiter'] ) ) {
 672                 if ( isset( $urlParts['scheme'] ) ) {
 673                         $result .= $urlParts['scheme'];
 674                 }
 675
 676                 $result .= $urlParts['delimiter'];
 677         }
 678
 679         if ( isset( $urlParts['host'] ) ) {
 680                 if ( isset( $urlParts['user'] ) ) {
 681                         $result .= $urlParts['user'];
 682                         if ( isset( $urlParts['pass'] ) ) {
 683                                 $result .= ':' . $urlParts['pass'];
 684                         }
 685                         $result .= '@';
 686                 }
 687
 688                 $result .= $urlParts['host'];
 689
 690                 if ( isset( $urlParts['port'] ) ) {
 691                         $result .= ':' . $urlParts['port'];
 692                 }
 693         }
 694
 695         if ( isset( $urlParts['path'] ) ) {
 696                 $result .= $urlParts['path'];
 697         }
 698
 699         if ( isset( $urlParts['query'] ) ) {
 700                 $result .= '?' . $urlParts['query'];
 701         }
 702
 703         if ( isset( $urlParts['fragment'] ) ) {
 704                 $result .= '#' . $urlParts['fragment'];
 705         }
 706
 707         return $result;
 708 }
 709
 710 /**
 711  * Remove all dot-segments in the provided URL path.  For example,
 712  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 713  * RFC3986 section 5.2.4.
 714  *
 715  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 716  *
 717  * @param string $urlPath URL path, potentially containing dot-segments
 718  * @return string URL path with all dot-segments removed
 719  */
 720 function wfRemoveDotSegments( $urlPath ) {
 721         $output = '';
 722         $inputOffset = 0;
 723         $inputLength = strlen( $urlPath );
 724
 725         while ( $inputOffset < $inputLength ) {
 726                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 727                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 728                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 729                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 730                 $trimOutput = false;
 731
 732                 if ( $prefixLengthTwo == './' ) {
 733                         # Step A, remove leading "./"
 734                         $inputOffset += 2;
 735                 } elseif ( $prefixLengthThree == '../' ) {
 736                         # Step A, remove leading "../"
 737                         $inputOffset += 3;
 738                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 739                         # Step B, replace leading "/.$" with "/"
 740                         $inputOffset += 1;
 741                         $urlPath[$inputOffset] = '/';
 742                 } elseif ( $prefixLengthThree == '/./' ) {
 743                         # Step B, replace leading "/./" with "/"
 744                         $inputOffset += 2;
 745                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 746                         # Step C, replace leading "/..$" with "/" and
 747                         # remove last path component in output
 748                         $inputOffset += 2;
 749                         $urlPath[$inputOffset] = '/';
 750                         $trimOutput = true;
 751                 } elseif ( $prefixLengthFour == '/../' ) {
 752                         # Step C, replace leading "/../" with "/" and
 753                         # remove last path component in output
 754                         $inputOffset += 3;
 755                         $trimOutput = true;
 756                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 757                         # Step D, remove "^.$"
 758                         $inputOffset += 1;
 759                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 760                         # Step D, remove "^..$"
 761                         $inputOffset += 2;
 762                 } else {
 763                         # Step E, move leading path segment to output
 764                         if ( $prefixLengthOne == '/' ) {
 765                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 766                         } else {
 767                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 768                         }
 769                         if ( $slashPos === false ) {
 770                                 $output .= substr( $urlPath, $inputOffset );
 771                                 $inputOffset = $inputLength;
 772                         } else {
 773                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 774                                 $inputOffset += $slashPos - $inputOffset;
 775                         }
 776                 }
 777
 778                 if ( $trimOutput ) {
 779                         $slashPos = strrpos( $output, '/' );
 780                         if ( $slashPos === false ) {
 781                                 $output = '';
 782                         } else {
 783                                 $output = substr( $output, 0, $slashPos );
 784                         }
 785                 }
 786         }
 787
 788         return $output;
 789 }
 790
 791 /**
 792  * Returns a regular expression of url protocols
 793  *
 794  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 795  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 796  * @return string
 797  */
 798 function wfUrlProtocols( $includeProtocolRelative = true ) {
 799         global $wgUrlProtocols;
 800
 801         // Cache return values separately based on $includeProtocolRelative
 802         static $withProtRel = null, $withoutProtRel = null;
 803         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 804         if ( !is_null( $cachedValue ) ) {
 805                 return $cachedValue;
 806         }
 807
 808         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 809         // with LocalSettings files from 1.5
 810         if ( is_array( $wgUrlProtocols ) ) {
 811                 $protocols = array();
 812                 foreach ( $wgUrlProtocols as $protocol ) {
 813                         // Filter out '//' if !$includeProtocolRelative
 814                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 815                                 $protocols[] = preg_quote( $protocol, '/' );
 816                         }
 817                 }
 818
 819                 $retval = implode( '|', $protocols );
 820         } else {
 821                 // Ignore $includeProtocolRelative in this case
 822                 // This case exists for pre-1.6 compatibility, and we can safely assume
 823                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 824                 // URLs weren't supported until 1.18
 825                 $retval = $wgUrlProtocols;
 826         }
 827
 828         // Cache return value
 829         if ( $includeProtocolRelative ) {
 830                 $withProtRel = $retval;
 831         } else {
 832                 $withoutProtRel = $retval;
 833         }
 834         return $retval;
 835 }
 836
 837 /**
 838  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 839  * you need a regex that matches all URL protocols but does not match protocol-
 840  * relative URLs
 841  * @return string
 842  */
 843 function wfUrlProtocolsWithoutProtRel() {
 844         return wfUrlProtocols( false );
 845 }
 846
 847 /**
 848  * parse_url() work-alike, but non-broken.  Differences:
 849  *
 850  * 1) Does not raise warnings on bad URLs (just returns false).
 851  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 852  *    protocol-relative URLs) correctly.
 853  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 854  *
 855  * @param string $url A URL to parse
 856  * @return string[] Bits of the URL in an associative array, per PHP docs
 857  */
 858 function wfParseUrl( $url ) {
 859         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 860
 861         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 862         // bad that the easiest way to handle them is to just prepend 'http:' and
 863         // strip the protocol out later.
 864         $wasRelative = substr( $url, 0, 2 ) == '//';
 865         if ( $wasRelative ) {
 866                 $url = "http:$url";
 867         }
 868         MediaWiki\suppressWarnings();
 869         $bits = parse_url( $url );
 870         MediaWiki\restoreWarnings();
 871         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 872         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 873         if ( !$bits || !isset( $bits['scheme'] ) ) {
 874                 return false;
 875         }
 876
 877         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 878         $bits['scheme'] = strtolower( $bits['scheme'] );
 879
 880         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 881         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 882                 $bits['delimiter'] = '://';
 883         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 884                 $bits['delimiter'] = ':';
 885                 // parse_url detects for news: and mailto: the host part of an url as path
 886                 // We have to correct this wrong detection
 887                 if ( isset( $bits['path'] ) ) {
 888                         $bits['host'] = $bits['path'];
 889                         $bits['path'] = '';
 890                 }
 891         } else {
 892                 return false;
 893         }
 894
 895         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 896         if ( !isset( $bits['host'] ) ) {
 897                 $bits['host'] = '';
 898
 899                 // bug 45069
 900                 if ( isset( $bits['path'] ) ) {
 901                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 902                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 903                                 $bits['path'] = '/' . $bits['path'];
 904                         }
 905                 } else {
 906                         $bits['path'] = '';
 907                 }
 908         }
 909
 910         // If the URL was protocol-relative, fix scheme and delimiter
 911         if ( $wasRelative ) {
 912                 $bits['scheme'] = '';
 913                 $bits['delimiter'] = '//';
 914         }
 915         return $bits;
 916 }
 917
 918 /**
 919  * Take a URL, make sure it's expanded to fully qualified, and replace any
 920  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 921  * for more compact display and legibility for local audiences.
 922  *
 923  * @todo handle punycode domains too
 924  *
 925  * @param string $url
 926  * @return string
 927  */
 928 function wfExpandIRI( $url ) {
 929         return preg_replace_callback(
 930                 '/((?:%[89A-F][0-9A-F])+)/i',
 931                 'wfExpandIRI_callback',
 932                 wfExpandUrl( $url )
 933         );
 934 }
 935
 936 /**
 937  * Private callback for wfExpandIRI
 938  * @param array $matches
 939  * @return string
 940  */
 941 function wfExpandIRI_callback( $matches ) {
 942         return urldecode( $matches[1] );
 943 }
 944
 945 /**
 946  * Make URL indexes, appropriate for the el_index field of externallinks.
 947  *
 948  * @param string $url
 949  * @return array
 950  */
 951 function wfMakeUrlIndexes( $url ) {
 952         $bits = wfParseUrl( $url );
 953
 954         // Reverse the labels in the hostname, convert to lower case
 955         // For emails reverse domainpart only
 956         if ( $bits['scheme'] == 'mailto' ) {
 957                 $mailparts = explode( '@', $bits['host'], 2 );
 958                 if ( count( $mailparts ) === 2 ) {
 959                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 960                 } else {
 961                         // No domain specified, don't mangle it
 962                         $domainpart = '';
 963                 }
 964                 $reversedHost = $domainpart . '@' . $mailparts[0];
 965         } else {
 966                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 967         }
 968         // Add an extra dot to the end
 969         // Why? Is it in wrong place in mailto links?
 970         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 971                 $reversedHost .= '.';
 972         }
 973         // Reconstruct the pseudo-URL
 974         $prot = $bits['scheme'];
 975         $index = $prot . $bits['delimiter'] . $reversedHost;
 976         // Leave out user and password. Add the port, path, query and fragment
 977         if ( isset( $bits['port'] ) ) {
 978                 $index .= ':' . $bits['port'];
 979         }
 980         if ( isset( $bits['path'] ) ) {
 981                 $index .= $bits['path'];
 982         } else {
 983                 $index .= '/';
 984         }
 985         if ( isset( $bits['query'] ) ) {
 986                 $index .= '?' . $bits['query'];
 987         }
 988         if ( isset( $bits['fragment'] ) ) {
 989                 $index .= '#' . $bits['fragment'];
 990         }
 991
 992         if ( $prot == '' ) {
 993                 return array( "http:$index", "https:$index" );
 994         } else {
 995                 return array( $index );
 996         }
 997 }
 998
 999 /**
1000  * Check whether a given URL has a domain that occurs in a given set of domains
1001  * @param string $url URL
1002  * @param array $domains Array of domains (strings)
1003  * @return bool True if the host part of $url ends in one of the strings in $domains
1004  */
1005 function wfMatchesDomainList( $url, $domains ) {
1006         $bits = wfParseUrl( $url );
1007         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1008                 $host = '.' . $bits['host'];
1009                 foreach ( (array)$domains as $domain ) {
1010                         $domain = '.' . $domain;
1011                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1012                                 return true;
1013                         }
1014                 }
1015         }
1016         return false;
1017 }
1018
1019 /**
1020  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1021  * In normal operation this is a NOP.
1022  *
1023  * Controlling globals:
1024  * $wgDebugLogFile - points to the log file
1025  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1026  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1027  *
1028  * @since 1.25 support for additional context data
1029  *
1030  * @param string $text
1031  * @param string|bool $dest Unused
1032  * @param array $context Additional logging context data
1033  */
1034 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1035         global $wgDebugRawPage, $wgDebugLogPrefix;
1036         global $wgDebugTimestamps, $wgRequestTime;
1037
1038         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1039                 return;
1040         }
1041
1042         $text = trim( $text );
1043
1044         // Inline logic from deprecated wfDebugTimer()
1045         if ( $wgDebugTimestamps ) {
1046                 $context['seconds_elapsed'] = sprintf(
1047                         '%6.4f',
1048                         microtime( true ) - $wgRequestTime
1049                 );
1050                 $context['memory_used'] = sprintf(
1051                         '%5.1fM',
1052                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1053                 );
1054         }
1055
1056         if ( $wgDebugLogPrefix !== '' ) {
1057                 $context['prefix'] = $wgDebugLogPrefix;
1058         }
1059
1060         $logger = LoggerFactory::getInstance( 'wfDebug' );
1061         $logger->debug( $text, $context );
1062 }
1063
1064 /**
1065  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1066  * @return bool
1067  */
1068 function wfIsDebugRawPage() {
1069         static $cache;
1070         if ( $cache !== null ) {
1071                 return $cache;
1072         }
1073         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1074         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1075                 || (
1076                         isset( $_SERVER['SCRIPT_NAME'] )
1077                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1078                 )
1079         ) {
1080                 $cache = true;
1081         } else {
1082                 $cache = false;
1083         }
1084         return $cache;
1085 }
1086
1087 /**
1088  * Get microsecond timestamps for debug logs
1089  *
1090  * @deprecated since 1.25
1091  * @return string
1092  */
1093 function wfDebugTimer() {
1094         global $wgDebugTimestamps, $wgRequestTime;
1095
1096         wfDeprecated( __METHOD__, '1.25' );
1097
1098         if ( !$wgDebugTimestamps ) {
1099                 return '';
1100         }
1101
1102         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1103         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1104         return "$prefix $mem  ";
1105 }
1106
1107 /**
1108  * Send a line giving PHP memory usage.
1109  *
1110  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1111  */
1112 function wfDebugMem( $exact = false ) {
1113         $mem = memory_get_usage();
1114         if ( !$exact ) {
1115                 $mem = floor( $mem / 1024 ) . ' KiB';
1116         } else {
1117                 $mem .= ' B';
1118         }
1119         wfDebug( "Memory usage: $mem\n" );
1120 }
1121
1122 /**
1123  * Send a line to a supplementary debug log file, if configured, or main debug
1124  * log if not.
1125  *
1126  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1127  * a string filename or an associative array mapping 'destination' to the
1128  * desired filename. The associative array may also contain a 'sample' key
1129  * with an integer value, specifying a sampling factor. Sampled log events
1130  * will be emitted with a 1 in N random chance.
1131  *
1132  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1133  * @since 1.25 support for additional context data
1134  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1135  *
1136  * @param string $logGroup
1137  * @param string $text
1138  * @param string|bool $dest Destination of the message:
1139  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1140  *     - 'log': only to the log and not in HTML
1141  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1142  *       discarded otherwise
1143  *   For backward compatibility, it can also take a boolean:
1144  *     - true: same as 'all'
1145  *     - false: same as 'private'
1146  * @param array $context Additional logging context data
1147  */
1148 function wfDebugLog(
1149         $logGroup, $text, $dest = 'all', array $context = array()
1150 ) {
1151         // Turn $dest into a string if it's a boolean (for b/c)
1152         if ( $dest === true ) {
1153                 $dest = 'all';
1154         } elseif ( $dest === false ) {
1155                 $dest = 'private';
1156         }
1157
1158         $text = trim( $text );
1159
1160         $logger = LoggerFactory::getInstance( $logGroup );
1161         $context['private'] = ( $dest === 'private' );
1162         $logger->info( $text, $context );
1163 }
1164
1165 /**
1166  * Log for database errors
1167  *
1168  * @since 1.25 support for additional context data
1169  *
1170  * @param string $text Database error message.
1171  * @param array $context Additional logging context data
1172  */
1173 function wfLogDBError( $text, array $context = array() ) {
1174         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1175         $logger->error( trim( $text ), $context );
1176 }
1177
1178 /**
1179  * Throws a warning that $function is deprecated
1180  *
1181  * @param string $function
1182  * @param string|bool $version Version of MediaWiki that the function
1183  *    was deprecated in (Added in 1.19).
1184  * @param string|bool $component Added in 1.19.
1185  * @param int $callerOffset How far up the call stack is the original
1186  *    caller. 2 = function that called the function that called
1187  *    wfDeprecated (Added in 1.20)
1188  *
1189  * @return null
1190  */
1191 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1192         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1193 }
1194
1195 /**
1196  * Send a warning either to the debug log or in a PHP error depending on
1197  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1198  *
1199  * @param string $msg Message to send
1200  * @param int $callerOffset Number of items to go back in the backtrace to
1201  *        find the correct caller (1 = function calling wfWarn, ...)
1202  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1203  *        only used when $wgDevelopmentWarnings is true
1204  */
1205 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1206         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1207 }
1208
1209 /**
1210  * Send a warning as a PHP error and the debug log. This is intended for logging
1211  * warnings in production. For logging development warnings, use WfWarn instead.
1212  *
1213  * @param string $msg Message to send
1214  * @param int $callerOffset Number of items to go back in the backtrace to
1215  *        find the correct caller (1 = function calling wfLogWarning, ...)
1216  * @param int $level PHP error level; defaults to E_USER_WARNING
1217  */
1218 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1219         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1220 }
1221
1222 /**
1223  * Log to a file without getting "file size exceeded" signals.
1224  *
1225  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1226  * send lines to the specified port, prefixed by the specified prefix and a space.
1227  * @since 1.25 support for additional context data
1228  *
1229  * @param string $text
1230  * @param string $file Filename
1231  * @param array $context Additional logging context data
1232  * @throws MWException
1233  * @deprecated since 1.25 Use MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1234  */
1235 function wfErrorLog( $text, $file, array $context = array() ) {
1236         wfDeprecated( __METHOD__, '1.25' );
1237         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1238         $context['destination'] = $file;
1239         $logger->info( trim( $text ), $context );
1240 }
1241
1242 /**
1243  * @todo document
1244  */
1245 function wfLogProfilingData() {
1246         global $wgDebugLogGroups, $wgDebugRawPage;
1247
1248         $context = RequestContext::getMain();
1249         $request = $context->getRequest();
1250
1251         $profiler = Profiler::instance();
1252         $profiler->setContext( $context );
1253         $profiler->logData();
1254
1255         $config = $context->getConfig();
1256         if ( $config->get( 'StatsdServer' ) ) {
1257                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1258                 $statsdHost = $statsdServer[0];
1259                 $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1260                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1261                 $statsdClient = new StatsdClient( $statsdSender );
1262                 $statsdClient->send( $context->getStats()->getBuffer() );
1263         }
1264
1265         # Profiling must actually be enabled...
1266         if ( $profiler instanceof ProfilerStub ) {
1267                 return;
1268         }
1269
1270         if ( isset( $wgDebugLogGroups['profileoutput'] )
1271                 && $wgDebugLogGroups['profileoutput'] === false
1272         ) {
1273                 // Explicitly disabled
1274                 return;
1275         }
1276         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1277                 return;
1278         }
1279
1280         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1281         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1282                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1283         }
1284         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1285                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1286         }
1287         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1288                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1289         }
1290         if ( isset( $ctx['forwarded_for'] ) ||
1291                 isset( $ctx['client_ip'] ) ||
1292                 isset( $ctx['from'] ) ) {
1293                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1294         }
1295
1296         // Don't load $wgUser at this late stage just for statistics purposes
1297         // @todo FIXME: We can detect some anons even if it is not loaded.
1298         // See User::getId()
1299         $user = $context->getUser();
1300         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1301
1302         // Command line script uses a FauxRequest object which does not have
1303         // any knowledge about an URL and throw an exception instead.
1304         try {
1305                 $ctx['url'] = urldecode( $request->getRequestURL() );
1306         } catch ( Exception $ignored ) {
1307                 // no-op
1308         }
1309
1310         $ctx['output'] = $profiler->getOutput();
1311
1312         $log = LoggerFactory::getInstance( 'profileoutput' );
1313         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1314 }
1315
1316 /**
1317  * Increment a statistics counter
1318  *
1319  * @param string $key
1320  * @param int $count
1321  * @return void
1322  */
1323 function wfIncrStats( $key, $count = 1 ) {
1324         $stats = RequestContext::getMain()->getStats();
1325         $stats->updateCount( $key, $count );
1326 }
1327
1328 /**
1329  * Check whether the wiki is in read-only mode.
1330  *
1331  * @return bool
1332  */
1333 function wfReadOnly() {
1334         return wfReadOnlyReason() !== false;
1335 }
1336
1337 /**
1338  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1339  *
1340  * @return string|bool String when in read-only mode; false otherwise
1341  */
1342 function wfReadOnlyReason() {
1343         global $wgReadOnly, $wgReadOnlyFile;
1344
1345         if ( $wgReadOnly === null ) {
1346                 // Set $wgReadOnly for faster access next time
1347                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1348                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1349                 } else {
1350                         $wgReadOnly = false;
1351                 }
1352                 // Callers use this method to be aware that data presented to a user
1353                 // may be very stale and thus allowing submissions can be problematic.
1354                 try {
1355                         if ( $wgReadOnly === false && wfGetLB()->getLaggedSlaveMode() ) {
1356                                 $wgReadOnly = 'The database has been automatically locked ' .
1357                                         'while the slave database servers catch up to the master';
1358                         }
1359                 } catch ( DBConnectionError $e ) {
1360                         $wgReadOnly = 'The database has been automatically locked ' .
1361                                 'until the slave database servers become available';
1362                 }
1363         }
1364
1365         return $wgReadOnly;
1366 }
1367
1368 /**
1369  * Return a Language object from $langcode
1370  *
1371  * @param Language|string|bool $langcode Either:
1372  *                  - a Language object
1373  *                  - code of the language to get the message for, if it is
1374  *                    a valid code create a language for that language, if
1375  *                    it is a string but not a valid code then make a basic
1376  *                    language object
1377  *                  - a boolean: if it's false then use the global object for
1378  *                    the current user's language (as a fallback for the old parameter
1379  *                    functionality), or if it is true then use global object
1380  *                    for the wiki's content language.
1381  * @return Language
1382  */
1383 function wfGetLangObj( $langcode = false ) {
1384         # Identify which language to get or create a language object for.
1385         # Using is_object here due to Stub objects.
1386         if ( is_object( $langcode ) ) {
1387                 # Great, we already have the object (hopefully)!
1388                 return $langcode;
1389         }
1390
1391         global $wgContLang, $wgLanguageCode;
1392         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1393                 # $langcode is the language code of the wikis content language object.
1394                 # or it is a boolean and value is true
1395                 return $wgContLang;
1396         }
1397
1398         global $wgLang;
1399         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1400                 # $langcode is the language code of user language object.
1401                 # or it was a boolean and value is false
1402                 return $wgLang;
1403         }
1404
1405         $validCodes = array_keys( Language::fetchLanguageNames() );
1406         if ( in_array( $langcode, $validCodes ) ) {
1407                 # $langcode corresponds to a valid language.
1408                 return Language::factory( $langcode );
1409         }
1410
1411         # $langcode is a string, but not a valid language code; use content language.
1412         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1413         return $wgContLang;
1414 }
1415
1416 /**
1417  * This is the function for getting translated interface messages.
1418  *
1419  * @see Message class for documentation how to use them.
1420  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1421  *
1422  * This function replaces all old wfMsg* functions.
1423  *
1424  * @param string|string[] $key Message key, or array of keys
1425  * @param mixed $params,... Normal message parameters
1426  * @return Message
1427  *
1428  * @since 1.17
1429  *
1430  * @see Message::__construct
1431  */
1432 function wfMessage( $key /*...*/ ) {
1433         $params = func_get_args();
1434         array_shift( $params );
1435         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1436                 $params = $params[0];
1437         }
1438         return new Message( $key, $params );
1439 }
1440
1441 /**
1442  * This function accepts multiple message keys and returns a message instance
1443  * for the first message which is non-empty. If all messages are empty then an
1444  * instance of the first message key is returned.
1445  *
1446  * @param string|string[] $keys,... Message keys
1447  * @return Message
1448  *
1449  * @since 1.18
1450  *
1451  * @see Message::newFallbackSequence
1452  */
1453 function wfMessageFallback( /*...*/ ) {
1454         $args = func_get_args();
1455         return call_user_func_array( 'Message::newFallbackSequence', $args );
1456 }
1457
1458 /**
1459  * Get a message from anywhere, for the current user language.
1460  *
1461  * Use wfMsgForContent() instead if the message should NOT
1462  * change depending on the user preferences.
1463  *
1464  * @deprecated since 1.18
1465  *
1466  * @param string $key Lookup key for the message, usually
1467  *    defined in languages/Language.php
1468  *
1469  * Parameters to the message, which can be used to insert variable text into
1470  * it, can be passed to this function in the following formats:
1471  * - One per argument, starting at the second parameter
1472  * - As an array in the second parameter
1473  * These are not shown in the function definition.
1474  *
1475  * @return string
1476  */
1477 function wfMsg( $key ) {
1478         wfDeprecated( __METHOD__, '1.21' );
1479
1480         $args = func_get_args();
1481         array_shift( $args );
1482         return wfMsgReal( $key, $args );
1483 }
1484
1485 /**
1486  * Same as above except doesn't transform the message
1487  *
1488  * @deprecated since 1.18
1489  *
1490  * @param string $key
1491  * @return string
1492  */
1493 function wfMsgNoTrans( $key ) {
1494         wfDeprecated( __METHOD__, '1.21' );
1495
1496         $args = func_get_args();
1497         array_shift( $args );
1498         return wfMsgReal( $key, $args, true, false, false );
1499 }
1500
1501 /**
1502  * Get a message from anywhere, for the current global language
1503  * set with $wgLanguageCode.
1504  *
1505  * Use this if the message should NOT change dependent on the
1506  * language set in the user's preferences. This is the case for
1507  * most text written into logs, as well as link targets (such as
1508  * the name of the copyright policy page). Link titles, on the
1509  * other hand, should be shown in the UI language.
1510  *
1511  * Note that MediaWiki allows users to change the user interface
1512  * language in their preferences, but a single installation
1513  * typically only contains content in one language.
1514  *
1515  * Be wary of this distinction: If you use wfMsg() where you should
1516  * use wfMsgForContent(), a user of the software may have to
1517  * customize potentially hundreds of messages in
1518  * order to, e.g., fix a link in every possible language.
1519  *
1520  * @deprecated since 1.18
1521  *
1522  * @param string $key Lookup key for the message, usually
1523  *     defined in languages/Language.php
1524  * @return string
1525  */
1526 function wfMsgForContent( $key ) {
1527         wfDeprecated( __METHOD__, '1.21' );
1528
1529         global $wgForceUIMsgAsContentMsg;
1530         $args = func_get_args();
1531         array_shift( $args );
1532         $forcontent = true;
1533         if ( is_array( $wgForceUIMsgAsContentMsg )
1534                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1535         ) {
1536                 $forcontent = false;
1537         }
1538         return wfMsgReal( $key, $args, true, $forcontent );
1539 }
1540
1541 /**
1542  * Same as above except doesn't transform the message
1543  *
1544  * @deprecated since 1.18
1545  *
1546  * @param string $key
1547  * @return string
1548  */
1549 function wfMsgForContentNoTrans( $key ) {
1550         wfDeprecated( __METHOD__, '1.21' );
1551
1552         global $wgForceUIMsgAsContentMsg;
1553         $args = func_get_args();
1554         array_shift( $args );
1555         $forcontent = true;
1556         if ( is_array( $wgForceUIMsgAsContentMsg )
1557                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1558         ) {
1559                 $forcontent = false;
1560         }
1561         return wfMsgReal( $key, $args, true, $forcontent, false );
1562 }
1563
1564 /**
1565  * Really get a message
1566  *
1567  * @deprecated since 1.18
1568  *
1569  * @param string $key Key to get.
1570  * @param array $args
1571  * @param bool $useDB
1572  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1573  * @param bool $transform Whether or not to transform the message.
1574  * @return string The requested message.
1575  */
1576 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1577         wfDeprecated( __METHOD__, '1.21' );
1578
1579         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1580         $message = wfMsgReplaceArgs( $message, $args );
1581         return $message;
1582 }
1583
1584 /**
1585  * Fetch a message string value, but don't replace any keys yet.
1586  *
1587  * @deprecated since 1.18
1588  *
1589  * @param string $key
1590  * @param bool $useDB
1591  * @param string|bool $langCode Code of the language to get the message for, or
1592  *   behaves as a content language switch if it is a boolean.
1593  * @param bool $transform Whether to parse magic words, etc.
1594  * @return string
1595  */
1596 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1597         wfDeprecated( __METHOD__, '1.21' );
1598
1599         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1600
1601         $cache = MessageCache::singleton();
1602         $message = $cache->get( $key, $useDB, $langCode );
1603         if ( $message === false ) {
1604                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1605         } elseif ( $transform ) {
1606                 $message = $cache->transform( $message );
1607         }
1608         return $message;
1609 }
1610
1611 /**
1612  * Replace message parameter keys on the given formatted output.
1613  *
1614  * @param string $message
1615  * @param array $args
1616  * @return string
1617  * @private
1618  */
1619 function wfMsgReplaceArgs( $message, $args ) {
1620         # Fix windows line-endings
1621         # Some messages are split with explode("\n", $msg)
1622         $message = str_replace( "\r", '', $message );
1623
1624         // Replace arguments
1625         if ( count( $args ) ) {
1626                 if ( is_array( $args[0] ) ) {
1627                         $args = array_values( $args[0] );
1628                 }
1629                 $replacementKeys = array();
1630                 foreach ( $args as $n => $param ) {
1631                         $replacementKeys['$' . ( $n + 1 )] = $param;
1632                 }
1633                 $message = strtr( $message, $replacementKeys );
1634         }
1635
1636         return $message;
1637 }
1638
1639 /**
1640  * Return an HTML-escaped version of a message.
1641  * Parameter replacements, if any, are done *after* the HTML-escaping,
1642  * so parameters may contain HTML (eg links or form controls). Be sure
1643  * to pre-escape them if you really do want plaintext, or just wrap
1644  * the whole thing in htmlspecialchars().
1645  *
1646  * @deprecated since 1.18
1647  *
1648  * @param string $key
1649  * @param string $args,... Parameters
1650  * @return string
1651  */
1652 function wfMsgHtml( $key ) {
1653         wfDeprecated( __METHOD__, '1.21' );
1654
1655         $args = func_get_args();
1656         array_shift( $args );
1657         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1658 }
1659
1660 /**
1661  * Return an HTML version of message
1662  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1663  * so parameters may contain HTML (eg links or form controls). Be sure
1664  * to pre-escape them if you really do want plaintext, or just wrap
1665  * the whole thing in htmlspecialchars().
1666  *
1667  * @deprecated since 1.18
1668  *
1669  * @param string $key
1670  * @param string $args,... Parameters
1671  * @return string
1672  */
1673 function wfMsgWikiHtml( $key ) {
1674         wfDeprecated( __METHOD__, '1.21' );
1675
1676         $args = func_get_args();
1677         array_shift( $args );
1678         return wfMsgReplaceArgs(
1679                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1680                 /* can't be set to false */ true, /* interface */ true )->getText(),
1681                 $args );
1682 }
1683
1684 /**
1685  * Returns message in the requested format
1686  *
1687  * @deprecated since 1.18
1688  *
1689  * @param string $key Key of the message
1690  * @param array $options Processing rules.
1691  *   Can take the following options:
1692  *     parse: parses wikitext to HTML
1693  *     parseinline: parses wikitext to HTML and removes the surrounding
1694  *       p's added by parser or tidy
1695  *     escape: filters message through htmlspecialchars
1696  *     escapenoentities: same, but allows entity references like &#160; through
1697  *     replaceafter: parameters are substituted after parsing or escaping
1698  *     parsemag: transform the message using magic phrases
1699  *     content: fetch message for content language instead of interface
1700  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1701  *     language: Language object or language code to fetch message for
1702  *       (overridden by content).
1703  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1704  *
1705  * @return string
1706  */
1707 function wfMsgExt( $key, $options ) {
1708         wfDeprecated( __METHOD__, '1.21' );
1709
1710         $args = func_get_args();
1711         array_shift( $args );
1712         array_shift( $args );
1713         $options = (array)$options;
1714         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1715                 'parsemag', 'content' );
1716
1717         foreach ( $options as $arrayKey => $option ) {
1718                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1719                         // An unknown index, neither numeric nor "language"
1720                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1721                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1722                         // A numeric index with unknown value
1723                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1724                 }
1725         }
1726
1727         if ( in_array( 'content', $options, true ) ) {
1728                 $forContent = true;
1729                 $langCode = true;
1730                 $langCodeObj = null;
1731         } elseif ( array_key_exists( 'language', $options ) ) {
1732                 $forContent = false;
1733                 $langCode = wfGetLangObj( $options['language'] );
1734                 $langCodeObj = $langCode;
1735         } else {
1736                 $forContent = false;
1737                 $langCode = false;
1738                 $langCodeObj = null;
1739         }
1740
1741         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1742
1743         if ( !in_array( 'replaceafter', $options, true ) ) {
1744                 $string = wfMsgReplaceArgs( $string, $args );
1745         }
1746
1747         $messageCache = MessageCache::singleton();
1748         $parseInline = in_array( 'parseinline', $options, true );
1749         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1750                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1751                 if ( $string instanceof ParserOutput ) {
1752                         $string = $string->getText();
1753                 }
1754
1755                 if ( $parseInline ) {
1756                         $string = Parser::stripOuterParagraph( $string );
1757                 }
1758         } elseif ( in_array( 'parsemag', $options, true ) ) {
1759                 $string = $messageCache->transform( $string,
1760                                 !$forContent, $langCodeObj );
1761         }
1762
1763         if ( in_array( 'escape', $options, true ) ) {
1764                 $string = htmlspecialchars( $string );
1765         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1766                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1767         }
1768
1769         if ( in_array( 'replaceafter', $options, true ) ) {
1770                 $string = wfMsgReplaceArgs( $string, $args );
1771         }
1772
1773         return $string;
1774 }
1775
1776 /**
1777  * Since wfMsg() and co suck, they don't return false if the message key they
1778  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1779  * nonexistence of messages by checking the MessageCache::get() result directly.
1780  *
1781  * @deprecated since 1.18. Use Message::isDisabled().
1782  *
1783  * @param string $key The message key looked up
1784  * @return bool True if the message *doesn't* exist.
1785  */
1786 function wfEmptyMsg( $key ) {
1787         wfDeprecated( __METHOD__, '1.21' );
1788
1789         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1790 }
1791
1792 /**
1793  * Fetch server name for use in error reporting etc.
1794  * Use real server name if available, so we know which machine
1795  * in a server farm generated the current page.
1796  *
1797  * @return string
1798  */
1799 function wfHostname() {
1800         static $host;
1801         if ( is_null( $host ) ) {
1802
1803                 # Hostname overriding
1804                 global $wgOverrideHostname;
1805                 if ( $wgOverrideHostname !== false ) {
1806                         # Set static and skip any detection
1807                         $host = $wgOverrideHostname;
1808                         return $host;
1809                 }
1810
1811                 if ( function_exists( 'posix_uname' ) ) {
1812                         // This function not present on Windows
1813                         $uname = posix_uname();
1814                 } else {
1815                         $uname = false;
1816                 }
1817                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1818                         $host = $uname['nodename'];
1819                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1820                         # Windows computer name
1821                         $host = getenv( 'COMPUTERNAME' );
1822                 } else {
1823                         # This may be a virtual server.
1824                         $host = $_SERVER['SERVER_NAME'];
1825                 }
1826         }
1827         return $host;
1828 }
1829
1830 /**
1831  * Returns a script tag that stores the amount of time it took MediaWiki to
1832  * handle the request in milliseconds as 'wgBackendResponseTime'.
1833  *
1834  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1835  * hostname of the server handling the request.
1836  *
1837  * @return string
1838  */
1839 function wfReportTime() {
1840         global $wgRequestTime, $wgShowHostnames;
1841
1842         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1843         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1844         if ( $wgShowHostnames ) {
1845                 $reportVars['wgHostname'] = wfHostname();
1846         }
1847         return Skin::makeVariablesScript( $reportVars );
1848 }
1849
1850 /**
1851  * Safety wrapper for debug_backtrace().
1852  *
1853  * Will return an empty array if debug_backtrace is disabled, otherwise
1854  * the output from debug_backtrace() (trimmed).
1855  *
1856  * @param int $limit This parameter can be used to limit the number of stack frames returned
1857  *
1858  * @return array Array of backtrace information
1859  */
1860 function wfDebugBacktrace( $limit = 0 ) {
1861         static $disabled = null;
1862
1863         if ( is_null( $disabled ) ) {
1864                 $disabled = !function_exists( 'debug_backtrace' );
1865                 if ( $disabled ) {
1866                         wfDebug( "debug_backtrace() is disabled\n" );
1867                 }
1868         }
1869         if ( $disabled ) {
1870                 return array();
1871         }
1872
1873         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1874                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1875         } else {
1876                 return array_slice( debug_backtrace(), 1 );
1877         }
1878 }
1879
1880 /**
1881  * Get a debug backtrace as a string
1882  *
1883  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1884  *   Defaults to $wgCommandLineMode if unset.
1885  * @return string
1886  * @since 1.25 Supports $raw parameter.
1887  */
1888 function wfBacktrace( $raw = null ) {
1889         global $wgCommandLineMode;
1890
1891         if ( $raw === null ) {
1892                 $raw = $wgCommandLineMode;
1893         }
1894
1895         if ( $raw ) {
1896                 $frameFormat = "%s line %s calls %s()\n";
1897                 $traceFormat = "%s";
1898         } else {
1899                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1900                 $traceFormat = "<ul>\n%s</ul>\n";
1901         }
1902
1903         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1904                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1905                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1906                 $call = $frame['function'];
1907                 if ( !empty( $frame['class'] ) ) {
1908                         $call = $frame['class'] . $frame['type'] . $call;
1909                 }
1910                 return sprintf( $frameFormat, $file, $line, $call );
1911         }, wfDebugBacktrace() );
1912
1913         return sprintf( $traceFormat, implode( '', $frames ) );
1914 }
1915
1916 /**
1917  * Get the name of the function which called this function
1918  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1919  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1920  * wfGetCaller( 3 ) is the parent of that.
1921  *
1922  * @param int $level
1923  * @return string
1924  */
1925 function wfGetCaller( $level = 2 ) {
1926         $backtrace = wfDebugBacktrace( $level + 1 );
1927         if ( isset( $backtrace[$level] ) ) {
1928                 return wfFormatStackFrame( $backtrace[$level] );
1929         } else {
1930                 return 'unknown';
1931         }
1932 }
1933
1934 /**
1935  * Return a string consisting of callers in the stack. Useful sometimes
1936  * for profiling specific points.
1937  *
1938  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1939  * @return string
1940  */
1941 function wfGetAllCallers( $limit = 3 ) {
1942         $trace = array_reverse( wfDebugBacktrace() );
1943         if ( !$limit || $limit > count( $trace ) - 1 ) {
1944                 $limit = count( $trace ) - 1;
1945         }
1946         $trace = array_slice( $trace, -$limit - 1, $limit );
1947         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1948 }
1949
1950 /**
1951  * Return a string representation of frame
1952  *
1953  * @param array $frame
1954  * @return string
1955  */
1956 function wfFormatStackFrame( $frame ) {
1957         return isset( $frame['class'] ) ?
1958                 $frame['class'] . '::' . $frame['function'] :
1959                 $frame['function'];
1960 }
1961
1962 /* Some generic result counters, pulled out of SearchEngine */
1963
1964 /**
1965  * @todo document
1966  *
1967  * @param int $offset
1968  * @param int $limit
1969  * @return string
1970  */
1971 function wfShowingResults( $offset, $limit ) {
1972         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1973 }
1974
1975 /**
1976  * @todo document
1977  * @todo FIXME: We may want to blacklist some broken browsers
1978  *
1979  * @param bool $force
1980  * @return bool Whereas client accept gzip compression
1981  */
1982 function wfClientAcceptsGzip( $force = false ) {
1983         static $result = null;
1984         if ( $result === null || $force ) {
1985                 $result = false;
1986                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1987                         # @todo FIXME: We may want to blacklist some broken browsers
1988                         $m = array();
1989                         if ( preg_match(
1990                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1991                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1992                                         $m
1993                                 )
1994                         ) {
1995                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1996                                         $result = false;
1997                                         return $result;
1998                                 }
1999                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2000                                 $result = true;
2001                         }
2002                 }
2003         }
2004         return $result;
2005 }
2006
2007 /**
2008  * Obtain the offset and limit values from the request string;
2009  * used in special pages
2010  *
2011  * @param int $deflimit Default limit if none supplied
2012  * @param string $optionname Name of a user preference to check against
2013  * @return array
2014  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2015  */
2016 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2017         global $wgRequest;
2018         wfDeprecated( __METHOD__, '1.24' );
2019         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2020 }
2021
2022 /**
2023  * Escapes the given text so that it may be output using addWikiText()
2024  * without any linking, formatting, etc. making its way through. This
2025  * is achieved by substituting certain characters with HTML entities.
2026  * As required by the callers, "<nowiki>" is not used.
2027  *
2028  * @param string $text Text to be escaped
2029  * @return string
2030  */
2031 function wfEscapeWikiText( $text ) {
2032         static $repl = null, $repl2 = null;
2033         if ( $repl === null ) {
2034                 $repl = array(
2035                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2036                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2037                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2038                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2039                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2040                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2041                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2042                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2043                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2044                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2045                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2046                         '__' => '_&#95;', '://' => '&#58;//',
2047                 );
2048
2049                 // We have to catch everything "\s" matches in PCRE
2050                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2051                         $repl["$magic "] = "$magic&#32;";
2052                         $repl["$magic\t"] = "$magic&#9;";
2053                         $repl["$magic\r"] = "$magic&#13;";
2054                         $repl["$magic\n"] = "$magic&#10;";
2055                         $repl["$magic\f"] = "$magic&#12;";
2056                 }
2057
2058                 // And handle protocols that don't use "://"
2059                 global $wgUrlProtocols;
2060                 $repl2 = array();
2061                 foreach ( $wgUrlProtocols as $prot ) {
2062                         if ( substr( $prot, -1 ) === ':' ) {
2063                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2064                         }
2065                 }
2066                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2067         }
2068         $text = substr( strtr( "\n$text", $repl ), 1 );
2069         $text = preg_replace( $repl2, '$1&#58;', $text );
2070         return $text;
2071 }
2072
2073 /**
2074  * Sets dest to source and returns the original value of dest
2075  * If source is NULL, it just returns the value, it doesn't set the variable
2076  * If force is true, it will set the value even if source is NULL
2077  *
2078  * @param mixed $dest
2079  * @param mixed $source
2080  * @param bool $force
2081  * @return mixed
2082  */
2083 function wfSetVar( &$dest, $source, $force = false ) {
2084         $temp = $dest;
2085         if ( !is_null( $source ) || $force ) {
2086                 $dest = $source;
2087         }
2088         return $temp;
2089 }
2090
2091 /**
2092  * As for wfSetVar except setting a bit
2093  *
2094  * @param int $dest
2095  * @param int $bit
2096  * @param bool $state
2097  *
2098  * @return bool
2099  */
2100 function wfSetBit( &$dest, $bit, $state = true ) {
2101         $temp = (bool)( $dest & $bit );
2102         if ( !is_null( $state ) ) {
2103                 if ( $state ) {
2104                         $dest |= $bit;
2105                 } else {
2106                         $dest &= ~$bit;
2107                 }
2108         }
2109         return $temp;
2110 }
2111
2112 /**
2113  * A wrapper around the PHP function var_export().
2114  * Either print it or add it to the regular output ($wgOut).
2115  *
2116  * @param mixed $var A PHP variable to dump.
2117  */
2118 function wfVarDump( $var ) {
2119         global $wgOut;
2120         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2121         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2122                 print $s;
2123         } else {
2124                 $wgOut->addHTML( $s );
2125         }
2126 }
2127
2128 /**
2129  * Provide a simple HTTP error.
2130  *
2131  * @param int|string $code
2132  * @param string $label
2133  * @param string $desc
2134  */
2135 function wfHttpError( $code, $label, $desc ) {
2136         global $wgOut;
2137         HttpStatus::header( $code );
2138         if ( $wgOut ) {
2139                 $wgOut->disable();
2140                 $wgOut->sendCacheControl();
2141         }
2142
2143         header( 'Content-type: text/html; charset=utf-8' );
2144         print '<!DOCTYPE html>' .
2145                 '<html><head><title>' .
2146                 htmlspecialchars( $label ) .
2147                 '</title></head><body><h1>' .
2148                 htmlspecialchars( $label ) .
2149                 '</h1><p>' .
2150                 nl2br( htmlspecialchars( $desc ) ) .
2151                 "</p></body></html>\n";
2152 }
2153
2154 /**
2155  * Clear away any user-level output buffers, discarding contents.
2156  *
2157  * Suitable for 'starting afresh', for instance when streaming
2158  * relatively large amounts of data without buffering, or wanting to
2159  * output image files without ob_gzhandler's compression.
2160  *
2161  * The optional $resetGzipEncoding parameter controls suppression of
2162  * the Content-Encoding header sent by ob_gzhandler; by default it
2163  * is left. See comments for wfClearOutputBuffers() for why it would
2164  * be used.
2165  *
2166  * Note that some PHP configuration options may add output buffer
2167  * layers which cannot be removed; these are left in place.
2168  *
2169  * @param bool $resetGzipEncoding
2170  */
2171 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2172         if ( $resetGzipEncoding ) {
2173                 // Suppress Content-Encoding and Content-Length
2174                 // headers from 1.10+s wfOutputHandler
2175                 global $wgDisableOutputCompression;
2176                 $wgDisableOutputCompression = true;
2177         }
2178         while ( $status = ob_get_status() ) {
2179                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2180                         // Probably from zlib.output_compression or other
2181                         // PHP-internal setting which can't be removed.
2182                         //
2183                         // Give up, and hope the result doesn't break
2184                         // output behavior.
2185                         break;
2186                 }
2187                 if ( !ob_end_clean() ) {
2188                         // Could not remove output buffer handler; abort now
2189                         // to avoid getting in some kind of infinite loop.
2190                         break;
2191                 }
2192                 if ( $resetGzipEncoding ) {
2193                         if ( $status['name'] == 'ob_gzhandler' ) {
2194                                 // Reset the 'Content-Encoding' field set by this handler
2195                                 // so we can start fresh.
2196                                 header_remove( 'Content-Encoding' );
2197                                 break;
2198                         }
2199                 }
2200         }
2201 }
2202
2203 /**
2204  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2205  *
2206  * Clear away output buffers, but keep the Content-Encoding header
2207  * produced by ob_gzhandler, if any.
2208  *
2209  * This should be used for HTTP 304 responses, where you need to
2210  * preserve the Content-Encoding header of the real result, but
2211  * also need to suppress the output of ob_gzhandler to keep to spec
2212  * and avoid breaking Firefox in rare cases where the headers and
2213  * body are broken over two packets.
2214  */
2215 function wfClearOutputBuffers() {
2216         wfResetOutputBuffers( false );
2217 }
2218
2219 /**
2220  * Converts an Accept-* header into an array mapping string values to quality
2221  * factors
2222  *
2223  * @param string $accept
2224  * @param string $def Default
2225  * @return float[] Associative array of string => float pairs
2226  */
2227 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2228         # No arg means accept anything (per HTTP spec)
2229         if ( !$accept ) {
2230                 return array( $def => 1.0 );
2231         }
2232
2233         $prefs = array();
2234
2235         $parts = explode( ',', $accept );
2236
2237         foreach ( $parts as $part ) {
2238                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2239                 $values = explode( ';', trim( $part ) );
2240                 $match = array();
2241                 if ( count( $values ) == 1 ) {
2242                         $prefs[$values[0]] = 1.0;
2243                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2244                         $prefs[$values[0]] = floatval( $match[1] );
2245                 }
2246         }
2247
2248         return $prefs;
2249 }
2250
2251 /**
2252  * Checks if a given MIME type matches any of the keys in the given
2253  * array. Basic wildcards are accepted in the array keys.
2254  *
2255  * Returns the matching MIME type (or wildcard) if a match, otherwise
2256  * NULL if no match.
2257  *
2258  * @param string $type
2259  * @param array $avail
2260  * @return string
2261  * @private
2262  */
2263 function mimeTypeMatch( $type, $avail ) {
2264         if ( array_key_exists( $type, $avail ) ) {
2265                 return $type;
2266         } else {
2267                 $parts = explode( '/', $type );
2268                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2269                         return $parts[0] . '/*';
2270                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2271                         return '*/*';
2272                 } else {
2273                         return null;
2274                 }
2275         }
2276 }
2277
2278 /**
2279  * Returns the 'best' match between a client's requested internet media types
2280  * and the server's list of available types. Each list should be an associative
2281  * array of type to preference (preference is a float between 0.0 and 1.0).
2282  * Wildcards in the types are acceptable.
2283  *
2284  * @param array $cprefs Client's acceptable type list
2285  * @param array $sprefs Server's offered types
2286  * @return string
2287  *
2288  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2289  * XXX: generalize to negotiate other stuff
2290  */
2291 function wfNegotiateType( $cprefs, $sprefs ) {
2292         $combine = array();
2293
2294         foreach ( array_keys( $sprefs ) as $type ) {
2295                 $parts = explode( '/', $type );
2296                 if ( $parts[1] != '*' ) {
2297                         $ckey = mimeTypeMatch( $type, $cprefs );
2298                         if ( $ckey ) {
2299                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2300                         }
2301                 }
2302         }
2303
2304         foreach ( array_keys( $cprefs ) as $type ) {
2305                 $parts = explode( '/', $type );
2306                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2307                         $skey = mimeTypeMatch( $type, $sprefs );
2308                         if ( $skey ) {
2309                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2310                         }
2311                 }
2312         }
2313
2314         $bestq = 0;
2315         $besttype = null;
2316
2317         foreach ( array_keys( $combine ) as $type ) {
2318                 if ( $combine[$type] > $bestq ) {
2319                         $besttype = $type;
2320                         $bestq = $combine[$type];
2321                 }
2322         }
2323
2324         return $besttype;
2325 }
2326
2327 /**
2328  * Reference-counted warning suppression
2329  *
2330  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2331  * @param bool $end
2332  */
2333 function wfSuppressWarnings( $end = false ) {
2334         MediaWiki\suppressWarnings( $end );
2335 }
2336
2337 /**
2338  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2339  * Restore error level to previous value
2340  */
2341 function wfRestoreWarnings() {
2342         MediaWiki\suppressWarnings( true );
2343 }
2344
2345 # Autodetect, convert and provide timestamps of various types
2346
2347 /**
2348  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2349  */
2350 define( 'TS_UNIX', 0 );
2351
2352 /**
2353  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2354  */
2355 define( 'TS_MW', 1 );
2356
2357 /**
2358  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2359  */
2360 define( 'TS_DB', 2 );
2361
2362 /**
2363  * RFC 2822 format, for E-mail and HTTP headers
2364  */
2365 define( 'TS_RFC2822', 3 );
2366
2367 /**
2368  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2369  *
2370  * This is used by Special:Export
2371  */
2372 define( 'TS_ISO_8601', 4 );
2373
2374 /**
2375  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2376  *
2377  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2378  *       DateTime tag and page 36 for the DateTimeOriginal and
2379  *       DateTimeDigitized tags.
2380  */
2381 define( 'TS_EXIF', 5 );
2382
2383 /**
2384  * Oracle format time.
2385  */
2386 define( 'TS_ORACLE', 6 );
2387
2388 /**
2389  * Postgres format time.
2390  */
2391 define( 'TS_POSTGRES', 7 );
2392
2393 /**
2394  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2395  */
2396 define( 'TS_ISO_8601_BASIC', 9 );
2397
2398 /**
2399  * Get a timestamp string in one of various formats
2400  *
2401  * @param mixed $outputtype A timestamp in one of the supported formats, the
2402  *   function will autodetect which format is supplied and act accordingly.
2403  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2404  * @return string|bool String / false The same date in the format specified in $outputtype or false
2405  */
2406 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2407         try {
2408                 $timestamp = new MWTimestamp( $ts );
2409                 return $timestamp->getTimestamp( $outputtype );
2410         } catch ( TimestampException $e ) {
2411                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2412                 return false;
2413         }
2414 }
2415
2416 /**
2417  * Return a formatted timestamp, or null if input is null.
2418  * For dealing with nullable timestamp columns in the database.
2419  *
2420  * @param int $outputtype
2421  * @param string $ts
2422  * @return string
2423  */
2424 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2425         if ( is_null( $ts ) ) {
2426                 return null;
2427         } else {
2428                 return wfTimestamp( $outputtype, $ts );
2429         }
2430 }
2431
2432 /**
2433  * Convenience function; returns MediaWiki timestamp for the present time.
2434  *
2435  * @return string
2436  */
2437 function wfTimestampNow() {
2438         # return NOW
2439         return wfTimestamp( TS_MW, time() );
2440 }
2441
2442 /**
2443  * Check if the operating system is Windows
2444  *
2445  * @return bool True if it's Windows, false otherwise.
2446  */
2447 function wfIsWindows() {
2448         static $isWindows = null;
2449         if ( $isWindows === null ) {
2450                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2451         }
2452         return $isWindows;
2453 }
2454
2455 /**
2456  * Check if we are running under HHVM
2457  *
2458  * @return bool
2459  */
2460 function wfIsHHVM() {
2461         return defined( 'HHVM_VERSION' );
2462 }
2463
2464 /**
2465  * Tries to get the system directory for temporary files. First
2466  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2467  * environment variables are then checked in sequence, and if none are
2468  * set try sys_get_temp_dir().
2469  *
2470  * NOTE: When possible, use instead the tmpfile() function to create
2471  * temporary files to avoid race conditions on file creation, etc.
2472  *
2473  * @return string
2474  */
2475 function wfTempDir() {
2476         global $wgTmpDirectory;
2477
2478         if ( $wgTmpDirectory !== false ) {
2479                 return $wgTmpDirectory;
2480         }
2481
2482         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2483
2484         foreach ( $tmpDir as $tmp ) {
2485                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2486                         return $tmp;
2487                 }
2488         }
2489         return sys_get_temp_dir();
2490 }
2491
2492 /**
2493  * Make directory, and make all parent directories if they don't exist
2494  *
2495  * @param string $dir Full path to directory to create
2496  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2497  * @param string $caller Optional caller param for debugging.
2498  * @throws MWException
2499  * @return bool
2500  */
2501 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2502         global $wgDirectoryMode;
2503
2504         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2505                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2506         }
2507
2508         if ( !is_null( $caller ) ) {
2509                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2510         }
2511
2512         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2513                 return true;
2514         }
2515
2516         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2517
2518         if ( is_null( $mode ) ) {
2519                 $mode = $wgDirectoryMode;
2520         }
2521
2522         // Turn off the normal warning, we're doing our own below
2523         MediaWiki\suppressWarnings();
2524         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2525         MediaWiki\restoreWarnings();
2526
2527         if ( !$ok ) {
2528                 //directory may have been created on another request since we last checked
2529                 if ( is_dir( $dir ) ) {
2530                         return true;
2531                 }
2532
2533                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2534                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2535         }
2536         return $ok;
2537 }
2538
2539 /**
2540  * Remove a directory and all its content.
2541  * Does not hide error.
2542  * @param string $dir
2543  */
2544 function wfRecursiveRemoveDir( $dir ) {
2545         wfDebug( __FUNCTION__ . "( $dir )\n" );
2546         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2547         if ( is_dir( $dir ) ) {
2548                 $objects = scandir( $dir );
2549                 foreach ( $objects as $object ) {
2550                         if ( $object != "." && $object != ".." ) {
2551                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2552                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2553                                 } else {
2554                                         unlink( $dir . '/' . $object );
2555                                 }
2556                         }
2557                 }
2558                 reset( $objects );
2559                 rmdir( $dir );
2560         }
2561 }
2562
2563 /**
2564  * @param int $nr The number to format
2565  * @param int $acc The number of digits after the decimal point, default 2
2566  * @param bool $round Whether or not to round the value, default true
2567  * @return string
2568  */
2569 function wfPercent( $nr, $acc = 2, $round = true ) {
2570         $ret = sprintf( "%.${acc}f", $nr );
2571         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2572 }
2573
2574 /**
2575  * Safety wrapper around ini_get() for boolean settings.
2576  * The values returned from ini_get() are pre-normalized for settings
2577  * set via php.ini or php_flag/php_admin_flag... but *not*
2578  * for those set via php_value/php_admin_value.
2579  *
2580  * It's fairly common for people to use php_value instead of php_flag,
2581  * which can leave you with an 'off' setting giving a false positive
2582  * for code that just takes the ini_get() return value as a boolean.
2583  *
2584  * To make things extra interesting, setting via php_value accepts
2585  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2586  * Unrecognized values go false... again opposite PHP's own coercion
2587  * from string to bool.
2588  *
2589  * Luckily, 'properly' set settings will always come back as '0' or '1',
2590  * so we only have to worry about them and the 'improper' settings.
2591  *
2592  * I frickin' hate PHP... :P
2593  *
2594  * @param string $setting
2595  * @return bool
2596  */
2597 function wfIniGetBool( $setting ) {
2598         $val = strtolower( ini_get( $setting ) );
2599         // 'on' and 'true' can't have whitespace around them, but '1' can.
2600         return $val == 'on'
2601                 || $val == 'true'
2602                 || $val == 'yes'
2603                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2604 }
2605
2606 /**
2607  * Windows-compatible version of escapeshellarg()
2608  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2609  * function puts single quotes in regardless of OS.
2610  *
2611  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2612  * earlier distro releases of PHP)
2613  *
2614  * @param string ... strings to escape and glue together, or a single array of strings parameter
2615  * @return string
2616  */
2617 function wfEscapeShellArg( /*...*/ ) {
2618         wfInitShellLocale();
2619
2620         $args = func_get_args();
2621         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2622                 // If only one argument has been passed, and that argument is an array,
2623                 // treat it as a list of arguments
2624                 $args = reset( $args );
2625         }
2626
2627         $first = true;
2628         $retVal = '';
2629         foreach ( $args as $arg ) {
2630                 if ( !$first ) {
2631                         $retVal .= ' ';
2632                 } else {
2633                         $first = false;
2634                 }
2635
2636                 if ( wfIsWindows() ) {
2637                         // Escaping for an MSVC-style command line parser and CMD.EXE
2638                         // @codingStandardsIgnoreStart For long URLs
2639                         // Refs:
2640                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2641                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2642                         //  * Bug #13518
2643                         //  * CR r63214
2644                         // Double the backslashes before any double quotes. Escape the double quotes.
2645                         // @codingStandardsIgnoreEnd
2646                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2647                         $arg = '';
2648                         $iteration = 0;
2649                         foreach ( $tokens as $token ) {
2650                                 if ( $iteration % 2 == 1 ) {
2651                                         // Delimiter, a double quote preceded by zero or more slashes
2652                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2653                                 } elseif ( $iteration % 4 == 2 ) {
2654                                         // ^ in $token will be outside quotes, need to be escaped
2655                                         $arg .= str_replace( '^', '^^', $token );
2656                                 } else { // $iteration % 4 == 0
2657                                         // ^ in $token will appear inside double quotes, so leave as is
2658                                         $arg .= $token;
2659                                 }
2660                                 $iteration++;
2661                         }
2662                         // Double the backslashes before the end of the string, because
2663                         // we will soon add a quote
2664                         $m = array();
2665                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2666                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2667                         }
2668
2669                         // Add surrounding quotes
2670                         $retVal .= '"' . $arg . '"';
2671                 } else {
2672                         $retVal .= escapeshellarg( $arg );
2673                 }
2674         }
2675         return $retVal;
2676 }
2677
2678 /**
2679  * Check if wfShellExec() is effectively disabled via php.ini config
2680  *
2681  * @return bool|string False or one of (safemode,disabled)
2682  * @since 1.22
2683  */
2684 function wfShellExecDisabled() {
2685         static $disabled = null;
2686         if ( is_null( $disabled ) ) {
2687                 if ( wfIniGetBool( 'safe_mode' ) ) {
2688                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2689                         $disabled = 'safemode';
2690                 } elseif ( !function_exists( 'proc_open' ) ) {
2691                         wfDebug( "proc_open() is disabled\n" );
2692                         $disabled = 'disabled';
2693                 } else {
2694                         $disabled = false;
2695                 }
2696         }
2697         return $disabled;
2698 }
2699
2700 /**
2701  * Execute a shell command, with time and memory limits mirrored from the PHP
2702  * configuration if supported.
2703  *
2704  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2705  *   or an array of unescaped arguments, in which case each value will be escaped
2706  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2707  * @param null|mixed &$retval Optional, will receive the program's exit code.
2708  *   (non-zero is usually failure). If there is an error from
2709  *   read, select, or proc_open(), this will be set to -1.
2710  * @param array $environ Optional environment variables which should be
2711  *   added to the executed command environment.
2712  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2713  *   this overwrites the global wgMaxShell* limits.
2714  * @param array $options Array of options:
2715  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2716  *     including errors from limit.sh
2717  *   - profileMethod: By default this function will profile based on the calling
2718  *     method. Set this to a string for an alternative method to profile from
2719  *
2720  * @return string Collected stdout as a string
2721  */
2722 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2723         $limits = array(), $options = array()
2724 ) {
2725         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2726                 $wgMaxShellWallClockTime, $wgShellCgroup;
2727
2728         $disabled = wfShellExecDisabled();
2729         if ( $disabled ) {
2730                 $retval = 1;
2731                 return $disabled == 'safemode' ?
2732                         'Unable to run external programs in safe mode.' :
2733                         'Unable to run external programs, proc_open() is disabled.';
2734         }
2735
2736         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2737         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2738
2739         wfInitShellLocale();
2740
2741         $envcmd = '';
2742         foreach ( $environ as $k => $v ) {
2743                 if ( wfIsWindows() ) {
2744                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2745                          * appear in the environment variable, so we must use carat escaping as documented in
2746                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2747                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2748                          * are listed there but doesn't appear to need it.
2749                          */
2750                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2751                 } else {
2752                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2753                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2754                          */
2755                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2756                 }
2757         }
2758         if ( is_array( $cmd ) ) {
2759                 $cmd = wfEscapeShellArg( $cmd );
2760         }
2761
2762         $cmd = $envcmd . $cmd;
2763
2764         $useLogPipe = false;
2765         if ( is_executable( '/bin/bash' ) ) {
2766                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2767                 if ( isset( $limits['walltime'] ) ) {
2768                         $wallTime = intval( $limits['walltime'] );
2769                 } elseif ( isset( $limits['time'] ) ) {
2770                         $wallTime = $time;
2771                 } else {
2772                         $wallTime = intval( $wgMaxShellWallClockTime );
2773                 }
2774                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2775                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2776
2777                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2778                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2779                                 escapeshellarg( $cmd ) . ' ' .
2780                                 escapeshellarg(
2781                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2782                                         "MW_CPU_LIMIT=$time; " .
2783                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2784                                         "MW_MEM_LIMIT=$mem; " .
2785                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2786                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2787                                         "MW_USE_LOG_PIPE=yes"
2788                                 );
2789                         $useLogPipe = true;
2790                 } elseif ( $includeStderr ) {
2791                         $cmd .= ' 2>&1';
2792                 }
2793         } elseif ( $includeStderr ) {
2794                 $cmd .= ' 2>&1';
2795         }
2796         wfDebug( "wfShellExec: $cmd\n" );
2797
2798         $desc = array(
2799                 0 => array( 'file', 'php://stdin', 'r' ),
2800                 1 => array( 'pipe', 'w' ),
2801                 2 => array( 'file', 'php://stderr', 'w' ) );
2802         if ( $useLogPipe ) {
2803                 $desc[3] = array( 'pipe', 'w' );
2804         }
2805         $pipes = null;
2806         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2807         $proc = proc_open( $cmd, $desc, $pipes );
2808         if ( !$proc ) {
2809                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2810                 $retval = -1;
2811                 return '';
2812         }
2813         $outBuffer = $logBuffer = '';
2814         $emptyArray = array();
2815         $status = false;
2816         $logMsg = false;
2817
2818         // According to the documentation, it is possible for stream_select()
2819         // to fail due to EINTR. I haven't managed to induce this in testing
2820         // despite sending various signals. If it did happen, the error
2821         // message would take the form:
2822         //
2823         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2824         //
2825         // where [4] is the value of the macro EINTR and "Interrupted system
2826         // call" is string which according to the Linux manual is "possibly"
2827         // localised according to LC_MESSAGES.
2828         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2829         $eintrMessage = "stream_select(): unable to select [$eintr]";
2830
2831         // Build a table mapping resource IDs to pipe FDs to work around a
2832         // PHP 5.3 issue in which stream_select() does not preserve array keys
2833         // <https://bugs.php.net/bug.php?id=53427>.
2834         $fds = array();
2835         foreach ( $pipes as $fd => $pipe ) {
2836                 $fds[(int)$pipe] = $fd;
2837         }
2838
2839         $running = true;
2840         $timeout = null;
2841         $numReadyPipes = 0;
2842
2843         while ( $running === true || $numReadyPipes !== 0 ) {
2844                 if ( $running ) {
2845                         $status = proc_get_status( $proc );
2846                         // If the process has terminated, switch to nonblocking selects
2847                         // for getting any data still waiting to be read.
2848                         if ( !$status['running'] ) {
2849                                 $running = false;
2850                                 $timeout = 0;
2851                         }
2852                 }
2853
2854                 $readyPipes = $pipes;
2855
2856                 // Clear last error
2857                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2858                 @trigger_error( '' );
2859                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2860                 if ( $numReadyPipes === false ) {
2861                         // @codingStandardsIgnoreEnd
2862                         $error = error_get_last();
2863                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2864                                 continue;
2865                         } else {
2866                                 trigger_error( $error['message'], E_USER_WARNING );
2867                                 $logMsg = $error['message'];
2868                                 break;
2869                         }
2870                 }
2871                 foreach ( $readyPipes as $pipe ) {
2872                         $block = fread( $pipe, 65536 );
2873                         $fd = $fds[(int)$pipe];
2874                         if ( $block === '' ) {
2875                                 // End of file
2876                                 fclose( $pipes[$fd] );
2877                                 unset( $pipes[$fd] );
2878                                 if ( !$pipes ) {
2879                                         break 2;
2880                                 }
2881                         } elseif ( $block === false ) {
2882                                 // Read error
2883                                 $logMsg = "Error reading from pipe";
2884                                 break 2;
2885                         } elseif ( $fd == 1 ) {
2886                                 // From stdout
2887                                 $outBuffer .= $block;
2888                         } elseif ( $fd == 3 ) {
2889                                 // From log FD
2890                                 $logBuffer .= $block;
2891                                 if ( strpos( $block, "\n" ) !== false ) {
2892                                         $lines = explode( "\n", $logBuffer );
2893                                         $logBuffer = array_pop( $lines );
2894                                         foreach ( $lines as $line ) {
2895                                                 wfDebugLog( 'exec', $line );
2896                                         }
2897                                 }
2898                         }
2899                 }
2900         }
2901
2902         foreach ( $pipes as $pipe ) {
2903                 fclose( $pipe );
2904         }
2905
2906         // Use the status previously collected if possible, since proc_get_status()
2907         // just calls waitpid() which will not return anything useful the second time.
2908         if ( $running ) {
2909                 $status = proc_get_status( $proc );
2910         }
2911
2912         if ( $logMsg !== false ) {
2913                 // Read/select error
2914                 $retval = -1;
2915                 proc_close( $proc );
2916         } elseif ( $status['signaled'] ) {
2917                 $logMsg = "Exited with signal {$status['termsig']}";
2918                 $retval = 128 + $status['termsig'];
2919                 proc_close( $proc );
2920         } else {
2921                 if ( $status['running'] ) {
2922                         $retval = proc_close( $proc );
2923                 } else {
2924                         $retval = $status['exitcode'];
2925                         proc_close( $proc );
2926                 }
2927                 if ( $retval == 127 ) {
2928                         $logMsg = "Possibly missing executable file";
2929                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2930                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2931                 }
2932         }
2933
2934         if ( $logMsg !== false ) {
2935                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2936         }
2937
2938         return $outBuffer;
2939 }
2940
2941 /**
2942  * Execute a shell command, returning both stdout and stderr. Convenience
2943  * function, as all the arguments to wfShellExec can become unwieldy.
2944  *
2945  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2946  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2947  *   or an array of unescaped arguments, in which case each value will be escaped
2948  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2949  * @param null|mixed &$retval Optional, will receive the program's exit code.
2950  *   (non-zero is usually failure)
2951  * @param array $environ Optional environment variables which should be
2952  *   added to the executed command environment.
2953  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2954  *   this overwrites the global wgMaxShell* limits.
2955  * @return string Collected stdout and stderr as a string
2956  */
2957 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2958         return wfShellExec( $cmd, $retval, $environ, $limits,
2959                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2960 }
2961
2962 /**
2963  * Workaround for http://bugs.php.net/bug.php?id=45132
2964  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2965  */
2966 function wfInitShellLocale() {
2967         static $done = false;
2968         if ( $done ) {
2969                 return;
2970         }
2971         $done = true;
2972         global $wgShellLocale;
2973         if ( !wfIniGetBool( 'safe_mode' ) ) {
2974                 putenv( "LC_CTYPE=$wgShellLocale" );
2975                 setlocale( LC_CTYPE, $wgShellLocale );
2976         }
2977 }
2978
2979 /**
2980  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2981  * Note that $parameters should be a flat array and an option with an argument
2982  * should consist of two consecutive items in the array (do not use "--option value").
2983  *
2984  * @param string $script MediaWiki cli script path
2985  * @param array $parameters Arguments and options to the script
2986  * @param array $options Associative array of options:
2987  *              'php': The path to the php executable
2988  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2989  * @return string
2990  */
2991 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2992         global $wgPhpCli;
2993         // Give site config file a chance to run the script in a wrapper.
2994         // The caller may likely want to call wfBasename() on $script.
2995         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2996         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2997         if ( isset( $options['wrapper'] ) ) {
2998                 $cmd[] = $options['wrapper'];
2999         }
3000         $cmd[] = $script;
3001         // Escape each parameter for shell
3002         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3003 }
3004
3005 /**
3006  * wfMerge attempts to merge differences between three texts.
3007  * Returns true for a clean merge and false for failure or a conflict.
3008  *
3009  * @param string $old
3010  * @param string $mine
3011  * @param string $yours
3012  * @param string $result
3013  * @return bool
3014  */
3015 function wfMerge( $old, $mine, $yours, &$result ) {
3016         global $wgDiff3;
3017
3018         # This check may also protect against code injection in
3019         # case of broken installations.
3020         MediaWiki\suppressWarnings();
3021         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3022         MediaWiki\restoreWarnings();
3023
3024         if ( !$haveDiff3 ) {
3025                 wfDebug( "diff3 not found\n" );
3026                 return false;
3027         }
3028
3029         # Make temporary files
3030         $td = wfTempDir();
3031         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3032         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3033         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3034
3035         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3036         #       a newline character. To avoid this, we normalize the trailing whitespace before
3037         #       creating the diff.
3038
3039         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3040         fclose( $oldtextFile );
3041         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3042         fclose( $mytextFile );
3043         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3044         fclose( $yourtextFile );
3045
3046         # Check for a conflict
3047         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3048                 $oldtextName, $yourtextName );
3049         $handle = popen( $cmd, 'r' );
3050
3051         if ( fgets( $handle, 1024 ) ) {
3052                 $conflict = true;
3053         } else {
3054                 $conflict = false;
3055         }
3056         pclose( $handle );
3057
3058         # Merge differences
3059         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3060                 $oldtextName, $yourtextName );
3061         $handle = popen( $cmd, 'r' );
3062         $result = '';
3063         do {
3064                 $data = fread( $handle, 8192 );
3065                 if ( strlen( $data ) == 0 ) {
3066                         break;
3067                 }
3068                 $result .= $data;
3069         } while ( true );
3070         pclose( $handle );
3071         unlink( $mytextName );
3072         unlink( $oldtextName );
3073         unlink( $yourtextName );
3074
3075         if ( $result === '' && $old !== '' && !$conflict ) {
3076                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3077                 $conflict = true;
3078         }
3079         return !$conflict;
3080 }
3081
3082 /**
3083  * Returns unified plain-text diff of two texts.
3084  * "Useful" for machine processing of diffs.
3085  *
3086  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3087  *
3088  * @param string $before The text before the changes.
3089  * @param string $after The text after the changes.
3090  * @param string $params Command-line options for the diff command.
3091  * @return string Unified diff of $before and $after
3092  */
3093 function wfDiff( $before, $after, $params = '-u' ) {
3094         if ( $before == $after ) {
3095                 return '';
3096         }
3097
3098         global $wgDiff;
3099         MediaWiki\suppressWarnings();
3100         $haveDiff = $wgDiff && file_exists( $wgDiff );
3101         MediaWiki\restoreWarnings();
3102
3103         # This check may also protect against code injection in
3104         # case of broken installations.
3105         if ( !$haveDiff ) {
3106                 wfDebug( "diff executable not found\n" );
3107                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3108                 $format = new UnifiedDiffFormatter();
3109                 return $format->format( $diffs );
3110         }
3111
3112         # Make temporary files
3113         $td = wfTempDir();
3114         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3115         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3116
3117         fwrite( $oldtextFile, $before );
3118         fclose( $oldtextFile );
3119         fwrite( $newtextFile, $after );
3120         fclose( $newtextFile );
3121
3122         // Get the diff of the two files
3123         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3124
3125         $h = popen( $cmd, 'r' );
3126         if ( !$h ) {
3127                 unlink( $oldtextName );
3128                 unlink( $newtextName );
3129                 throw new Exception( __METHOD__ . '(): popen() failed' );
3130         }
3131
3132         $diff = '';
3133
3134         do {
3135                 $data = fread( $h, 8192 );
3136                 if ( strlen( $data ) == 0 ) {
3137                         break;
3138                 }
3139                 $diff .= $data;
3140         } while ( true );
3141
3142         // Clean up
3143         pclose( $h );
3144         unlink( $oldtextName );
3145         unlink( $newtextName );
3146
3147         // Kill the --- and +++ lines. They're not useful.
3148         $diff_lines = explode( "\n", $diff );
3149         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3150                 unset( $diff_lines[0] );
3151         }
3152         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3153                 unset( $diff_lines[1] );
3154         }
3155
3156         $diff = implode( "\n", $diff_lines );
3157
3158         return $diff;
3159 }
3160
3161 /**
3162  * This function works like "use VERSION" in Perl, the program will die with a
3163  * backtrace if the current version of PHP is less than the version provided
3164  *
3165  * This is useful for extensions which due to their nature are not kept in sync
3166  * with releases, and might depend on other versions of PHP than the main code
3167  *
3168  * Note: PHP might die due to parsing errors in some cases before it ever
3169  *       manages to call this function, such is life
3170  *
3171  * @see perldoc -f use
3172  *
3173  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3174  * @throws MWException
3175  */
3176 function wfUsePHP( $req_ver ) {
3177         $php_ver = PHP_VERSION;
3178
3179         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3180                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3181         }
3182 }
3183
3184 /**
3185  * This function works like "use VERSION" in Perl except it checks the version
3186  * of MediaWiki, the program will die with a backtrace if the current version
3187  * of MediaWiki is less than the version provided.
3188  *
3189  * This is useful for extensions which due to their nature are not kept in sync
3190  * with releases
3191  *
3192  * Note: Due to the behavior of PHP's version_compare() which is used in this
3193  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3194  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3195  * targeted version number. For example if you wanted to allow any variation
3196  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3197  * not result in the same comparison due to the internal logic of
3198  * version_compare().
3199  *
3200  * @see perldoc -f use
3201  *
3202  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3203  * @throws MWException
3204  */
3205 function wfUseMW( $req_ver ) {
3206         global $wgVersion;
3207
3208         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3209                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3210         }
3211 }
3212
3213 /**
3214  * Return the final portion of a pathname.
3215  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3216  * http://bugs.php.net/bug.php?id=33898
3217  *
3218  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3219  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3220  *
3221  * @param string $path
3222  * @param string $suffix String to remove if present
3223  * @return string
3224  */
3225 function wfBaseName( $path, $suffix = '' ) {
3226         if ( $suffix == '' ) {
3227                 $encSuffix = '';
3228         } else {
3229                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3230         }
3231
3232         $matches = array();
3233         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3234                 return $matches[1];
3235         } else {
3236                 return '';
3237         }
3238 }
3239
3240 /**
3241  * Generate a relative path name to the given file.
3242  * May explode on non-matching case-insensitive paths,
3243  * funky symlinks, etc.
3244  *
3245  * @param string $path Absolute destination path including target filename
3246  * @param string $from Absolute source path, directory only
3247  * @return string
3248  */
3249 function wfRelativePath( $path, $from ) {
3250         // Normalize mixed input on Windows...
3251         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3252         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3253
3254         // Trim trailing slashes -- fix for drive root
3255         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3256         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3257
3258         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3259         $against = explode( DIRECTORY_SEPARATOR, $from );
3260
3261         if ( $pieces[0] !== $against[0] ) {
3262                 // Non-matching Windows drive letters?
3263                 // Return a full path.
3264                 return $path;
3265         }
3266
3267         // Trim off common prefix
3268         while ( count( $pieces ) && count( $against )
3269                 && $pieces[0] == $against[0] ) {
3270                 array_shift( $pieces );
3271                 array_shift( $against );
3272         }
3273
3274         // relative dots to bump us to the parent
3275         while ( count( $against ) ) {
3276                 array_unshift( $pieces, '..' );
3277                 array_shift( $against );
3278         }
3279
3280         array_push( $pieces, wfBaseName( $path ) );
3281
3282         return implode( DIRECTORY_SEPARATOR, $pieces );
3283 }
3284
3285 /**
3286  * Convert an arbitrarily-long digit string from one numeric base
3287  * to another, optionally zero-padding to a minimum column width.
3288  *
3289  * Supports base 2 through 36; digit values 10-36 are represented
3290  * as lowercase letters a-z. Input is case-insensitive.
3291  *
3292  * @param string $input Input number
3293  * @param int $sourceBase Base of the input number
3294  * @param int $destBase Desired base of the output
3295  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3296  * @param bool $lowercase Whether to output in lowercase or uppercase
3297  * @param string $engine Either "gmp", "bcmath", or "php"
3298  * @return string|bool The output number as a string, or false on error
3299  */
3300 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3301         $lowercase = true, $engine = 'auto'
3302 ) {
3303         $input = (string)$input;
3304         if (
3305                 $sourceBase < 2 ||
3306                 $sourceBase > 36 ||
3307                 $destBase < 2 ||
3308                 $destBase > 36 ||
3309                 $sourceBase != (int)$sourceBase ||
3310                 $destBase != (int)$destBase ||
3311                 $pad != (int)$pad ||
3312                 !preg_match(
3313                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3314                         $input
3315                 )
3316         ) {
3317                 return false;
3318         }
3319
3320         static $baseChars = array(
3321                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3322                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3323                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3324                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3325                 34 => 'y', 35 => 'z',
3326
3327                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3328                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3329                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3330                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3331                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3332                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3333         );
3334
3335         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3336                 // Removing leading zeros works around broken base detection code in
3337                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3338                 // <https://bugs.php.net/bug.php?id=55398>).
3339                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ) ?: '0', $sourceBase ), $destBase );
3340         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3341                 $decimal = '0';
3342                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3343                         $decimal = bcmul( $decimal, $sourceBase );
3344                         $decimal = bcadd( $decimal, $baseChars[$char] );
3345                 }
3346
3347                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3348                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3349                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3350                 }
3351                 // @codingStandardsIgnoreEnd
3352
3353                 $result = strrev( $result );
3354         } else {
3355                 $inDigits = array();
3356                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3357                         $inDigits[] = $baseChars[$char];
3358                 }
3359
3360                 // Iterate over the input, modulo-ing out an output digit
3361                 // at a time until input is gone.
3362                 $result = '';
3363                 while ( $inDigits ) {
3364                         $work = 0;
3365                         $workDigits = array();
3366
3367                         // Long division...
3368                         foreach ( $inDigits as $digit ) {
3369                                 $work *= $sourceBase;
3370                                 $work += $digit;
3371
3372                                 if ( $workDigits || $work >= $destBase ) {
3373                                         $workDigits[] = (int)( $work / $destBase );
3374                                 }
3375                                 $work %= $destBase;
3376                         }
3377
3378                         // All that division leaves us with a remainder,
3379                         // which is conveniently our next output digit.
3380                         $result .= $baseChars[$work];
3381
3382                         // And we continue!
3383                         $inDigits = $workDigits;
3384                 }
3385
3386                 $result = strrev( $result );
3387         }
3388
3389         if ( !$lowercase ) {
3390                 $result = strtoupper( $result );
3391         }
3392
3393         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3394 }
3395
3396 /**
3397  * Check if there is sufficient entropy in php's built-in session generation
3398  *
3399  * @return bool True = there is sufficient entropy
3400  */
3401 function wfCheckEntropy() {
3402         return (
3403                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3404                         || ini_get( 'session.entropy_file' )
3405                 )
3406                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3407 }
3408
3409 /**
3410  * Override session_id before session startup if php's built-in
3411  * session generation code is not secure.
3412  */
3413 function wfFixSessionID() {
3414         // If the cookie or session id is already set we already have a session and should abort
3415         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3416                 return;
3417         }
3418
3419         // PHP's built-in session entropy is enabled if:
3420         // - entropy_file is set or you're on Windows with php 5.3.3+
3421         // - AND entropy_length is > 0
3422         // We treat it as disabled if it doesn't have an entropy length of at least 32
3423         $entropyEnabled = wfCheckEntropy();
3424
3425         // If built-in entropy is not enabled or not sufficient override PHP's
3426         // built in session id generation code
3427         if ( !$entropyEnabled ) {
3428                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3429                         "overriding session id generation using our cryptrand source.\n" );
3430                 session_id( MWCryptRand::generateHex( 32 ) );
3431         }
3432 }
3433
3434 /**
3435  * Reset the session_id
3436  *
3437  * @since 1.22
3438  */
3439 function wfResetSessionID() {
3440         global $wgCookieSecure;
3441         $oldSessionId = session_id();
3442         $cookieParams = session_get_cookie_params();
3443         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3444                 session_regenerate_id( false );
3445         } else {
3446                 $tmp = $_SESSION;
3447                 session_destroy();
3448                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3449                 $_SESSION = $tmp;
3450         }
3451         $newSessionId = session_id();
3452         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3453 }
3454
3455 /**
3456  * Initialise php session
3457  *
3458  * @param bool $sessionId
3459  */
3460 function wfSetupSession( $sessionId = false ) {
3461         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3462                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3463         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3464                 ObjectCacheSessionHandler::install();
3465         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3466                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3467                 # hasn't already been set to the desired value (that causes errors)
3468                 ini_set( 'session.save_handler', $wgSessionHandler );
3469         }
3470         session_set_cookie_params(
3471                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3472         session_cache_limiter( 'private, must-revalidate' );
3473         if ( $sessionId ) {
3474                 session_id( $sessionId );
3475         } else {
3476                 wfFixSessionID();
3477         }
3478         MediaWiki\suppressWarnings();
3479         session_start();
3480         MediaWiki\restoreWarnings();
3481 }
3482
3483 /**
3484  * Get an object from the precompiled serialized directory
3485  *
3486  * @param string $name
3487  * @return mixed The variable on success, false on failure
3488  */
3489 function wfGetPrecompiledData( $name ) {
3490         global $IP;
3491
3492         $file = "$IP/serialized/$name";
3493         if ( file_exists( $file ) ) {
3494                 $blob = file_get_contents( $file );
3495                 if ( $blob ) {
3496                         return unserialize( $blob );
3497                 }
3498         }
3499         return false;
3500 }
3501
3502 /**
3503  * Make a cache key for the local wiki.
3504  *
3505  * @param string $args,...
3506  * @return string
3507  */
3508 function wfMemcKey( /*...*/ ) {
3509         global $wgCachePrefix;
3510         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3511         $args = func_get_args();
3512         $key = $prefix . ':' . implode( ':', $args );
3513         return strtr( $key, ' ', '_' );
3514 }
3515
3516 /**
3517  * Make a cache key for a foreign DB.
3518  *
3519  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3520  *
3521  * @param string $db
3522  * @param string $prefix
3523  * @param string $args,...
3524  * @return string
3525  */
3526 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3527         $args = array_slice( func_get_args(), 2 );
3528         if ( $prefix ) {
3529                 // Match wfWikiID() logic
3530                 $key = "$db-$prefix:" . implode( ':', $args );
3531         } else {
3532                 $key = $db . ':' . implode( ':', $args );
3533         }
3534         return strtr( $key, ' ', '_' );
3535 }
3536
3537 /**
3538  * Make a cache key with database-agnostic prefix.
3539  *
3540  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3541  * instead. Must have a prefix as otherwise keys that use a database name
3542  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3543  *
3544  * @since 1.26
3545  * @param string $args,...
3546  * @return string
3547  */
3548 function wfGlobalCacheKey( /*...*/ ) {
3549         $args = func_get_args();
3550         $key = 'global:' . implode( ':', $args );
3551         return strtr( $key, ' ', '_' );
3552 }
3553
3554 /**
3555  * Get an ASCII string identifying this wiki
3556  * This is used as a prefix in memcached keys
3557  *
3558  * @return string
3559  */
3560 function wfWikiID() {
3561         global $wgDBprefix, $wgDBname;
3562         if ( $wgDBprefix ) {
3563                 return "$wgDBname-$wgDBprefix";
3564         } else {
3565                 return $wgDBname;
3566         }
3567 }
3568
3569 /**
3570  * Split a wiki ID into DB name and table prefix
3571  *
3572  * @param string $wiki
3573  *
3574  * @return array
3575  */
3576 function wfSplitWikiID( $wiki ) {
3577         $bits = explode( '-', $wiki, 2 );
3578         if ( count( $bits ) < 2 ) {
3579                 $bits[] = '';
3580         }
3581         return $bits;
3582 }
3583
3584 /**
3585  * Get a Database object.
3586  *
3587  * @param int $db Index of the connection to get. May be DB_MASTER for the
3588  *            master (for write queries), DB_SLAVE for potentially lagged read
3589  *            queries, or an integer >= 0 for a particular server.
3590  *
3591  * @param string|string[] $groups Query groups. An array of group names that this query
3592  *                belongs to. May contain a single string if the query is only
3593  *                in one group.
3594  *
3595  * @param string|bool $wiki The wiki ID, or false for the current wiki
3596  *
3597  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3598  * will always return the same object, unless the underlying connection or load
3599  * balancer is manually destroyed.
3600  *
3601  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3602  * updater to ensure that a proper database is being updated.
3603  *
3604  * @return DatabaseBase
3605  */
3606 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3607         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3608 }
3609
3610 /**
3611  * Get a load balancer object.
3612  *
3613  * @param string|bool $wiki Wiki ID, or false for the current wiki
3614  * @return LoadBalancer
3615  */
3616 function wfGetLB( $wiki = false ) {
3617         return wfGetLBFactory()->getMainLB( $wiki );
3618 }
3619
3620 /**
3621  * Get the load balancer factory object
3622  *
3623  * @return LBFactory
3624  */
3625 function wfGetLBFactory() {
3626         return LBFactory::singleton();
3627 }
3628
3629 /**
3630  * Find a file.
3631  * Shortcut for RepoGroup::singleton()->findFile()
3632  *
3633  * @param string $title String or Title object
3634  * @param array $options Associative array of options (see RepoGroup::findFile)
3635  * @return File|bool File, or false if the file does not exist
3636  */
3637 function wfFindFile( $title, $options = array() ) {
3638         return RepoGroup::singleton()->findFile( $title, $options );
3639 }
3640
3641 /**
3642  * Get an object referring to a locally registered file.
3643  * Returns a valid placeholder object if the file does not exist.
3644  *
3645  * @param Title|string $title
3646  * @return LocalFile|null A File, or null if passed an invalid Title
3647  */
3648 function wfLocalFile( $title ) {
3649         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3650 }
3651
3652 /**
3653  * Should low-performance queries be disabled?
3654  *
3655  * @return bool
3656  * @codeCoverageIgnore
3657  */
3658 function wfQueriesMustScale() {
3659         global $wgMiserMode;
3660         return $wgMiserMode
3661                 || ( SiteStats::pages() > 100000
3662                 && SiteStats::edits() > 1000000
3663                 && SiteStats::users() > 10000 );
3664 }
3665
3666 /**
3667  * Get the path to a specified script file, respecting file
3668  * extensions; this is a wrapper around $wgScriptExtension etc.
3669  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3670  *
3671  * @param string $script Script filename, sans extension
3672  * @return string
3673  */
3674 function wfScript( $script = 'index' ) {
3675         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3676         if ( $script === 'index' ) {
3677                 return $wgScript;
3678         } elseif ( $script === 'load' ) {
3679                 return $wgLoadScript;
3680         } else {
3681                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3682         }
3683 }
3684
3685 /**
3686  * Get the script URL.
3687  *
3688  * @return string Script URL
3689  */
3690 function wfGetScriptUrl() {
3691         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3692                 #
3693                 # as it was called, minus the query string.
3694                 #
3695                 # Some sites use Apache rewrite rules to handle subdomains,
3696                 # and have PHP set up in a weird way that causes PHP_SELF
3697                 # to contain the rewritten URL instead of the one that the
3698                 # outside world sees.
3699                 #
3700                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3701                 # provides containing the "before" URL.
3702                 return $_SERVER['SCRIPT_NAME'];
3703         } else {
3704                 return $_SERVER['URL'];
3705         }
3706 }
3707
3708 /**
3709  * Convenience function converts boolean values into "true"
3710  * or "false" (string) values
3711  *
3712  * @param bool $value
3713  * @return string
3714  */
3715 function wfBoolToStr( $value ) {
3716         return $value ? 'true' : 'false';
3717 }
3718
3719 /**
3720  * Get a platform-independent path to the null file, e.g. /dev/null
3721  *
3722  * @return string
3723  */
3724 function wfGetNull() {
3725         return wfIsWindows() ? 'NUL' : '/dev/null';
3726 }
3727
3728 /**
3729  * Waits for the slaves to catch up to the master position
3730  *
3731  * Use this when updating very large numbers of rows, as in maintenance scripts,
3732  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3733  *
3734  * By default this waits on the main DB cluster of the current wiki.
3735  * If $cluster is set to "*" it will wait on all DB clusters, including
3736  * external ones. If the lag being waiting on is caused by the code that
3737  * does this check, it makes since to use $ifWritesSince, particularly if
3738  * cluster is "*", to avoid excess overhead.
3739  *
3740  * Never call this function after a big DB write that is still in a transaction.
3741  * This only makes sense after the possible lag inducing changes were committed.
3742  *
3743  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3744  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3745  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3746  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3747  * @return bool Success (able to connect and no timeouts reached)
3748  */
3749 function wfWaitForSlaves(
3750         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3751 ) {
3752         // B/C: first argument used to be "max seconds of lag"; ignore such values
3753         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3754
3755         if ( $timeout === null ) {
3756                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3757         }
3758
3759         // Figure out which clusters need to be checked
3760         /** @var LoadBalancer[] $lbs */
3761         $lbs = array();
3762         if ( $cluster === '*' ) {
3763                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3764                         $lbs[] = $lb;
3765                 } );
3766         } elseif ( $cluster !== false ) {
3767                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3768         } else {
3769                 $lbs[] = wfGetLB( $wiki );
3770         }
3771
3772         // Get all the master positions of applicable DBs right now.
3773         // This can be faster since waiting on one cluster reduces the
3774         // time needed to wait on the next clusters.
3775         $masterPositions = array_fill( 0, count( $lbs ), false );
3776         foreach ( $lbs as $i => $lb ) {
3777                 if ( $lb->getServerCount() <= 1 ) {
3778                         // Bug 27975 - Don't try to wait for slaves if there are none
3779                         // Prevents permission error when getting master position
3780                         continue;
3781                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3782                         continue; // no writes since the last wait
3783                 }
3784                 $masterPositions[$i] = $lb->getMasterPos();
3785         }
3786
3787         $ok = true;
3788         foreach ( $lbs as $i => $lb ) {
3789                 if ( $masterPositions[$i] ) {
3790                         // The DBMS may not support getMasterPos() or the whole
3791                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3792                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3793                 }
3794         }
3795
3796         return $ok;
3797 }
3798
3799 /**
3800  * Count down from $seconds to zero on the terminal, with a one-second pause
3801  * between showing each number. For use in command-line scripts.
3802  *
3803  * @codeCoverageIgnore
3804  * @param int $seconds
3805  */
3806 function wfCountDown( $seconds ) {
3807         for ( $i = $seconds; $i >= 0; $i-- ) {
3808                 if ( $i != $seconds ) {
3809                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3810                 }
3811                 echo $i;
3812                 flush();
3813                 if ( $i ) {
3814                         sleep( 1 );
3815                 }
3816         }
3817         echo "\n";
3818 }
3819
3820 /**
3821  * Replace all invalid characters with -
3822  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3823  * By default, $wgIllegalFileChars = ':'
3824  *
3825  * @param string $name Filename to process
3826  * @return string
3827  */
3828 function wfStripIllegalFilenameChars( $name ) {
3829         global $wgIllegalFileChars;
3830         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3831         $name = wfBaseName( $name );
3832         $name = preg_replace(
3833                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3834                 '-',
3835                 $name
3836         );
3837         return $name;
3838 }
3839
3840 /**
3841  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3842  *
3843  * @return int Value the memory limit was set to.
3844  */
3845 function wfMemoryLimit() {
3846         global $wgMemoryLimit;
3847         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3848         if ( $memlimit != -1 ) {
3849                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3850                 if ( $conflimit == -1 ) {
3851                         wfDebug( "Removing PHP's memory limit\n" );
3852                         MediaWiki\suppressWarnings();
3853                         ini_set( 'memory_limit', $conflimit );
3854                         MediaWiki\restoreWarnings();
3855                         return $conflimit;
3856                 } elseif ( $conflimit > $memlimit ) {
3857                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3858                         MediaWiki\suppressWarnings();
3859                         ini_set( 'memory_limit', $conflimit );
3860                         MediaWiki\restoreWarnings();
3861                         return $conflimit;
3862                 }
3863         }
3864         return $memlimit;
3865 }
3866
3867 /**
3868  * Converts shorthand byte notation to integer form
3869  *
3870  * @param string $string
3871  * @return int
3872  */
3873 function wfShorthandToInteger( $string = '' ) {
3874         $string = trim( $string );
3875         if ( $string === '' ) {
3876                 return -1;
3877         }
3878         $last = $string[strlen( $string ) - 1];
3879         $val = intval( $string );
3880         switch ( $last ) {
3881                 case 'g':
3882                 case 'G':
3883                         $val *= 1024;
3884                         // break intentionally missing
3885                 case 'm':
3886                 case 'M':
3887                         $val *= 1024;
3888                         // break intentionally missing
3889                 case 'k':
3890                 case 'K':
3891                         $val *= 1024;
3892         }
3893
3894         return $val;
3895 }
3896
3897 /**
3898  * Get the normalised IETF language tag
3899  * See unit test for examples.
3900  *
3901  * @param string $code The language code.
3902  * @return string The language code which complying with BCP 47 standards.
3903  */
3904 function wfBCP47( $code ) {
3905         $codeSegment = explode( '-', $code );
3906         $codeBCP = array();
3907         foreach ( $codeSegment as $segNo => $seg ) {
3908                 // when previous segment is x, it is a private segment and should be lc
3909                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3910                         $codeBCP[$segNo] = strtolower( $seg );
3911                 // ISO 3166 country code
3912                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3913                         $codeBCP[$segNo] = strtoupper( $seg );
3914                 // ISO 15924 script code
3915                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3916                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3917                 // Use lowercase for other cases
3918                 } else {
3919                         $codeBCP[$segNo] = strtolower( $seg );
3920                 }
3921         }
3922         $langCode = implode( '-', $codeBCP );
3923         return $langCode;
3924 }
3925
3926 /**
3927  * Get a cache object.
3928  *
3929  * @param int $inputType Cache type, one of the CACHE_* constants.
3930  * @return BagOStuff
3931  */
3932 function wfGetCache( $inputType ) {
3933         return ObjectCache::getInstance( $inputType );
3934 }
3935
3936 /**
3937  * Get the main cache object
3938  *
3939  * @return BagOStuff
3940  */
3941 function wfGetMainCache() {
3942         global $wgMainCacheType;
3943         return ObjectCache::getInstance( $wgMainCacheType );
3944 }
3945
3946 /**
3947  * Get the cache object used by the message cache
3948  *
3949  * @return BagOStuff
3950  */
3951 function wfGetMessageCacheStorage() {
3952         global $wgMessageCacheType;
3953         return ObjectCache::getInstance( $wgMessageCacheType );
3954 }
3955
3956 /**
3957  * Get the cache object used by the parser cache
3958  *
3959  * @return BagOStuff
3960  */
3961 function wfGetParserCacheStorage() {
3962         global $wgParserCacheType;
3963         return ObjectCache::getInstance( $wgParserCacheType );
3964 }
3965
3966 /**
3967  * Call hook functions defined in $wgHooks
3968  *
3969  * @param string $event Event name
3970  * @param array $args Parameters passed to hook functions
3971  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3972  *
3973  * @return bool True if no handler aborted the hook
3974  * @deprecated 1.25 - use Hooks::run
3975  */
3976 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3977         return Hooks::run( $event, $args, $deprecatedVersion );
3978 }
3979
3980 /**
3981  * Wrapper around php's unpack.
3982  *
3983  * @param string $format The format string (See php's docs)
3984  * @param string $data A binary string of binary data
3985  * @param int|bool $length The minimum length of $data or false. This is to
3986  *      prevent reading beyond the end of $data. false to disable the check.
3987  *
3988  * Also be careful when using this function to read unsigned 32 bit integer
3989  * because php might make it negative.
3990  *
3991  * @throws MWException If $data not long enough, or if unpack fails
3992  * @return array Associative array of the extracted data
3993  */
3994 function wfUnpack( $format, $data, $length = false ) {
3995         if ( $length !== false ) {
3996                 $realLen = strlen( $data );
3997                 if ( $realLen < $length ) {
3998                         throw new MWException( "Tried to use wfUnpack on a "
3999                                 . "string of length $realLen, but needed one "
4000                                 . "of at least length $length."
4001                         );
4002                 }
4003         }
4004
4005         MediaWiki\suppressWarnings();
4006         $result = unpack( $format, $data );
4007         MediaWiki\restoreWarnings();
4008
4009         if ( $result === false ) {
4010                 // If it cannot extract the packed data.
4011                 throw new MWException( "unpack could not unpack binary data" );
4012         }
4013         return $result;
4014 }
4015
4016 /**
4017  * Determine if an image exists on the 'bad image list'.
4018  *
4019  * The format of MediaWiki:Bad_image_list is as follows:
4020  *    * Only list items (lines starting with "*") are considered
4021  *    * The first link on a line must be a link to a bad image
4022  *    * Any subsequent links on the same line are considered to be exceptions,
4023  *      i.e. articles where the image may occur inline.
4024  *
4025  * @param string $name The image name to check
4026  * @param Title|bool $contextTitle The page on which the image occurs, if known
4027  * @param string $blacklist Wikitext of a file blacklist
4028  * @return bool
4029  */
4030 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4031         static $badImageCache = null; // based on bad_image_list msg
4032
4033         # Handle redirects
4034         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4035         if ( $redirectTitle ) {
4036                 $name = $redirectTitle->getDBkey();
4037         }
4038
4039         # Run the extension hook
4040         $bad = false;
4041         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4042                 return $bad;
4043         }
4044
4045         $cacheable = ( $blacklist === null );
4046         if ( $cacheable && $badImageCache !== null ) {
4047                 $badImages = $badImageCache;
4048         } else { // cache miss
4049                 if ( $blacklist === null ) {
4050                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4051                 }
4052                 # Build the list now
4053                 $badImages = array();
4054                 $lines = explode( "\n", $blacklist );
4055                 foreach ( $lines as $line ) {
4056                         # List items only
4057                         if ( substr( $line, 0, 1 ) !== '*' ) {
4058                                 continue;
4059                         }
4060
4061                         # Find all links
4062                         $m = array();
4063                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4064                                 continue;
4065                         }
4066
4067                         $exceptions = array();
4068                         $imageDBkey = false;
4069                         foreach ( $m[1] as $i => $titleText ) {
4070                                 $title = Title::newFromText( $titleText );
4071                                 if ( !is_null( $title ) ) {
4072                                         if ( $i == 0 ) {
4073                                                 $imageDBkey = $title->getDBkey();
4074                                         } else {
4075                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4076                                         }
4077                                 }
4078                         }
4079
4080                         if ( $imageDBkey !== false ) {
4081                                 $badImages[$imageDBkey] = $exceptions;
4082                         }
4083                 }
4084                 if ( $cacheable ) {
4085                         $badImageCache = $badImages;
4086                 }
4087         }
4088
4089         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4090         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4091         return $bad;
4092 }
4093
4094 /**
4095  * Determine whether the client at a given source IP is likely to be able to
4096  * access the wiki via HTTPS.
4097  *
4098  * @param string $ip The IPv4/6 address in the normal human-readable form
4099  * @return bool
4100  */
4101 function wfCanIPUseHTTPS( $ip ) {
4102         $canDo = true;
4103         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4104         return !!$canDo;
4105 }
4106
4107 /**
4108  * Determine input string is represents as infinity
4109  *
4110  * @param string $str The string to determine
4111  * @return bool
4112  * @since 1.25
4113  */
4114 function wfIsInfinity( $str ) {
4115         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4116         return in_array( $str, $infinityValues );
4117 }
4118
4119 /**
4120  * Work out the IP address based on various globals
4121  * For trusted proxies, use the XFF client IP (first of the chain)
4122  *
4123  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4124  * @return string
4125  */
4126 function wfGetIP() {
4127         wfDeprecated( __METHOD__, '1.19' );
4128         global $wgRequest;
4129         return $wgRequest->getIP();
4130 }
4131
4132 /**
4133  * Checks if an IP is a trusted proxy provider.
4134  * Useful to tell if X-Forwarded-For data is possibly bogus.
4135  * Squid cache servers for the site are whitelisted.
4136  * @deprecated Since 1.24, use IP::isTrustedProxy()
4137  *
4138  * @param string $ip
4139  * @return bool
4140  */
4141 function wfIsTrustedProxy( $ip ) {
4142         wfDeprecated( __METHOD__, '1.24' );
4143         return IP::isTrustedProxy( $ip );
4144 }
4145
4146 /**
4147  * Checks if an IP matches a proxy we've configured.
4148  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4149  *
4150  * @param string $ip
4151  * @return bool
4152  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4153  */
4154 function wfIsConfiguredProxy( $ip ) {
4155         wfDeprecated( __METHOD__, '1.24' );
4156         return IP::isConfiguredProxy( $ip );
4157 }
4158
4159 /**
4160  * Returns true if these thumbnail parameters match one that MediaWiki
4161  * requests from file description pages and/or parser output.
4162  *
4163  * $params is considered non-standard if they involve a non-standard
4164  * width or any non-default parameters aside from width and page number.
4165  * The number of possible files with standard parameters is far less than
4166  * that of all combinations; rate-limiting for them can thus be more generious.
4167  *
4168  * @param File $file
4169  * @param array $params
4170  * @return bool
4171  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4172  */
4173 function wfThumbIsStandard( File $file, array $params ) {
4174         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4175
4176         $multipliers = array( 1 );
4177         if ( $wgResponsiveImages ) {
4178                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4179                 // @see Linker::processResponsiveImages
4180                 $multipliers[] = 1.5;
4181                 $multipliers[] = 2;
4182         }
4183
4184         $handler = $file->getHandler();
4185         if ( !$handler || !isset( $params['width'] ) ) {
4186                 return false;
4187         }
4188
4189         $basicParams = array();
4190         if ( isset( $params['page'] ) ) {
4191                 $basicParams['page'] = $params['page'];
4192         }
4193
4194         $thumbLimits = array();
4195         $imageLimits = array();
4196         // Expand limits to account for multipliers
4197         foreach ( $multipliers as $multiplier ) {
4198                 $thumbLimits = array_merge( $thumbLimits, array_map(
4199                         function ( $width ) use ( $multiplier ) {
4200                                 return round( $width * $multiplier );
4201                         }, $wgThumbLimits )
4202                 );
4203                 $imageLimits = array_merge( $imageLimits, array_map(
4204                         function ( $pair ) use ( $multiplier ) {
4205                                 return array(
4206                                         round( $pair[0] * $multiplier ),
4207                                         round( $pair[1] * $multiplier ),
4208                                 );
4209                         }, $wgImageLimits )
4210                 );
4211         }
4212
4213         // Check if the width matches one of $wgThumbLimits
4214         if ( in_array( $params['width'], $thumbLimits ) ) {
4215                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4216                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4217                 $handler->normaliseParams( $file, $normalParams );
4218         } else {
4219                 // If not, then check if the width matchs one of $wgImageLimits
4220                 $match = false;
4221                 foreach ( $imageLimits as $pair ) {
4222                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4223                         // Decide whether the thumbnail should be scaled on width or height.
4224                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4225                         $handler->normaliseParams( $file, $normalParams );
4226                         // Check if this standard thumbnail size maps to the given width
4227                         if ( $normalParams['width'] == $params['width'] ) {
4228                                 $match = true;
4229                                 break;
4230                         }
4231                 }
4232                 if ( !$match ) {
4233                         return false; // not standard for description pages
4234                 }
4235         }
4236
4237         // Check that the given values for non-page, non-width, params are just defaults
4238         foreach ( $params as $key => $value ) {
4239                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4240                         return false;
4241                 }
4242         }
4243
4244         return true;
4245 }