includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere
   4  * @file
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die( "This file is part of MediaWiki, it is not a valid entry point" );
   9 }
  10
  11 // Hide compatibility functions from Doxygen
  12 /// @cond
  13
  14 /**
  15  * Compatibility functions
  16  *
  17  * We support PHP 5.2.3 and up.
  18  * Re-implementations of newer functions or functions in non-standard
  19  * PHP extensions may be included here.
  20  */
  21
  22 if( !function_exists( 'iconv' ) ) {
  23         /** @codeCoverageIgnore */
  24         function iconv( $from, $to, $string ) {
  25                 return Fallback::iconv( $from, $to, $string );
  26         }
  27 }
  28
  29 if ( !function_exists( 'mb_substr' ) ) {
  30         /** @codeCoverageIgnore */
  31         function mb_substr( $str, $start, $count='end' ) {
  32                 return Fallback::mb_substr( $str, $start, $count );
  33         }
  34
  35         /** @codeCoverageIgnore */
  36         function mb_substr_split_unicode( $str, $splitPos ) {
  37                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  38         }
  39 }
  40
  41 if ( !function_exists( 'mb_strlen' ) ) {
  42         /** @codeCoverageIgnore */
  43         function mb_strlen( $str, $enc = '' ) {
  44                 return Fallback::mb_strlen( $str, $enc );
  45         }
  46 }
  47
  48 if( !function_exists( 'mb_strpos' ) ) {
  49         /** @codeCoverageIgnore */
  50         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  51                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  52         }
  53
  54 }
  55
  56 if( !function_exists( 'mb_strrpos' ) ) {
  57         /** @codeCoverageIgnore */
  58         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  59                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  60         }
  61 }
  62
  63
  64 // Support for Wietse Venema's taint feature
  65 if ( !function_exists( 'istainted' ) ) {
  66         /** @codeCoverageIgnore */
  67         function istainted( $var ) {
  68                 return 0;
  69         }
  70         /** @codeCoverageIgnore */
  71         function taint( $var, $level = 0 ) {}
  72         /** @codeCoverageIgnore */
  73         function untaint( $var, $level = 0 ) {}
  74         define( 'TC_HTML', 1 );
  75         define( 'TC_SHELL', 1 );
  76         define( 'TC_MYSQL', 1 );
  77         define( 'TC_PCRE', 1 );
  78         define( 'TC_SELF', 1 );
  79 }
  80 /// @endcond
  81
  82 /**
  83  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
  84  */
  85 function wfArrayDiff2( $a, $b ) {
  86         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  87 }
  88
  89 /**
  90  * @param $a
  91  * @param $b
  92  * @return int
  93  */
  94 function wfArrayDiff2_cmp( $a, $b ) {
  95         if ( !is_array( $a ) ) {
  96                 return strcmp( $a, $b );
  97         } elseif ( count( $a ) !== count( $b ) ) {
  98                 return count( $a ) < count( $b ) ? -1 : 1;
  99         } else {
 100                 reset( $a );
 101                 reset( $b );
 102                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 103                         $cmp = strcmp( $valueA, $valueB );
 104                         if ( $cmp !== 0 ) {
 105                                 return $cmp;
 106                         }
 107                 }
 108                 return 0;
 109         }
 110 }
 111
 112 /**
 113  * Array lookup
 114  * Returns an array where the values in the first array are replaced by the
 115  * values in the second array with the corresponding keys
 116  *
 117  * @param $a Array
 118  * @param $b Array
 119  * @return array
 120  */
 121 function wfArrayLookup( $a, $b ) {
 122         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 123 }
 124
 125 /**
 126  * Appends to second array if $value differs from that in $default
 127  *
 128  * @param $key String|Int
 129  * @param $value Mixed
 130  * @param $default Mixed
 131  * @param $changed Array to alter
 132  */
 133 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 134         if ( is_null( $changed ) ) {
 135                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 136         }
 137         if ( $default[$key] !== $value ) {
 138                 $changed[$key] = $value;
 139         }
 140 }
 141
 142 /**
 143  * Backwards array plus for people who haven't bothered to read the PHP manual
 144  * XXX: will not darn your socks for you.
 145  *
 146  * @param $array1 Array
 147  * @param [$array2, [...]] Arrays
 148  * @return Array
 149  */
 150 function wfArrayMerge( $array1/* ... */ ) {
 151         $args = func_get_args();
 152         $args = array_reverse( $args, true );
 153         $out = array();
 154         foreach ( $args as $arg ) {
 155                 $out += $arg;
 156         }
 157         return $out;
 158 }
 159
 160 /**
 161  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 162  * e.g.
 163  *      wfMergeErrorArrays(
 164  *              array( array( 'x' ) ),
 165  *              array( array( 'x', '2' ) ),
 166  *              array( array( 'x' ) ),
 167  *              array( array( 'y') )
 168  *      );
 169  * returns:
 170  *              array(
 171  *              array( 'x', '2' ),
 172  *              array( 'x' ),
 173  *              array( 'y' )
 174  *      )
 175  * @param varargs
 176  * @return Array
 177  */
 178 function wfMergeErrorArrays( /*...*/ ) {
 179         $args = func_get_args();
 180         $out = array();
 181         foreach ( $args as $errors ) {
 182                 foreach ( $errors as $params ) {
 183                         # @todo FIXME: Sometimes get nested arrays for $params,
 184                         # which leads to E_NOTICEs
 185                         $spec = implode( "\t", $params );
 186                         $out[$spec] = $params;
 187                 }
 188         }
 189         return array_values( $out );
 190 }
 191
 192 /**
 193  * Insert array into another array after the specified *KEY*
 194  *
 195  * @param $array Array: The array.
 196  * @param $insert Array: The array to insert.
 197  * @param $after Mixed: The key to insert after
 198  * @return Array
 199  */
 200 function wfArrayInsertAfter( $array, $insert, $after ) {
 201         // Find the offset of the element to insert after.
 202         $keys = array_keys( $array );
 203         $offsetByKey = array_flip( $keys );
 204
 205         $offset = $offsetByKey[$after];
 206
 207         // Insert at the specified offset
 208         $before = array_slice( $array, 0, $offset + 1, true );
 209         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 210
 211         $output = $before + $insert + $after;
 212
 213         return $output;
 214 }
 215
 216 /**
 217  * Recursively converts the parameter (an object) to an array with the same data
 218  *
 219  * @param $objOrArray Object|Array
 220  * @param $recursive Bool
 221  * @return Array
 222  */
 223 function wfObjectToArray( $objOrArray, $recursive = true ) {
 224         $array = array();
 225         if( is_object( $objOrArray ) ) {
 226                 $objOrArray = get_object_vars( $objOrArray );
 227         }
 228         foreach ( $objOrArray as $key => $value ) {
 229                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 230                         $value = wfObjectToArray( $value );
 231                 }
 232
 233                 $array[$key] = $value;
 234         }
 235
 236         return $array;
 237 }
 238
 239 /**
 240  * Wrapper around array_map() which also taints variables
 241  *
 242  * @param  $function Callback
 243  * @param  $input Array
 244  * @return Array
 245  */
 246 function wfArrayMap( $function, $input ) {
 247         $ret = array_map( $function, $input );
 248         foreach ( $ret as $key => $value ) {
 249                 $taint = istainted( $input[$key] );
 250                 if ( $taint ) {
 251                         taint( $ret[$key], $taint );
 252                 }
 253         }
 254         return $ret;
 255 }
 256
 257 /**
 258  * Get a random decimal value between 0 and 1, in a way
 259  * not likely to give duplicate values for any realistic
 260  * number of articles.
 261  *
 262  * @return string
 263  */
 264 function wfRandom() {
 265         # The maximum random value is "only" 2^31-1, so get two random
 266         # values to reduce the chance of dupes
 267         $max = mt_getrandmax() + 1;
 268         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 269                 / $max / $max, 12, '.', '' );
 270         return $rand;
 271 }
 272
 273 /**
 274  * We want some things to be included as literal characters in our title URLs
 275  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 276  * all of the following should be safe:
 277  *
 278  * ;:@&=$-_.+!*'(),
 279  *
 280  * But + is not safe because it's used to indicate a space; &= are only safe in
 281  * paths and not in queries (and we don't distinguish here); ' seems kind of
 282  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 283  * is reserved, we don't care.  So the list we unescape is:
 284  *
 285  * ;:@$!*(),/
 286  *
 287  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 288  * so no fancy : for IIS7.
 289  *
 290  * %2F in the page titles seems to fatally break for some reason.
 291  *
 292  * @param $s String:
 293  * @return string
 294 */
 295 function wfUrlencode( $s ) {
 296         static $needle;
 297         if ( is_null( $s ) ) {
 298                 $needle = null;
 299                 return;
 300         }
 301
 302         if ( is_null( $needle ) ) {
 303                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 304                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 305                         $needle[] = '%3A';
 306                 }
 307         }
 308
 309         $s = urlencode( $s );
 310         $s = str_ireplace(
 311                 $needle,
 312                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 313                 $s
 314         );
 315
 316         return $s;
 317 }
 318
 319 /**
 320  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 321  * "days=7&limit=100". Options in the first array override options in the second.
 322  * Options set to "" will not be output.
 323  *
 324  * @param $array1 Array ( String|Array )
 325  * @param $array2 Array ( String|Array )
 326  * @param $prefix String
 327  * @return String
 328  */
 329 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 330         if ( !is_null( $array2 ) ) {
 331                 $array1 = $array1 + $array2;
 332         }
 333
 334         $cgi = '';
 335         foreach ( $array1 as $key => $value ) {
 336                 if ( $value !== '' ) {
 337                         if ( $cgi != '' ) {
 338                                 $cgi .= '&';
 339                         }
 340                         if ( $prefix !== '' ) {
 341                                 $key = $prefix . "[$key]";
 342                         }
 343                         if ( is_array( $value ) ) {
 344                                 $firstTime = true;
 345                                 foreach ( $value as $k => $v ) {
 346                                         $cgi .= $firstTime ? '' : '&';
 347                                         if ( is_array( $v ) ) {
 348                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 349                                         } else {
 350                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 351                                         }
 352                                         $firstTime = false;
 353                                 }
 354                         } else {
 355                                 if ( is_object( $value ) ) {
 356                                         $value = $value->__toString();
 357                                 }
 358                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 359                         }
 360                 }
 361         }
 362         return $cgi;
 363 }
 364
 365 /**
 366  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 367  * its argument and returns the same string in array form.  This allows compa-
 368  * tibility with legacy functions that accept raw query strings instead of nice
 369  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 370  * valid query strings, or it will explode.
 371  *
 372  * @param $query String: query string
 373  * @return array Array version of input
 374  */
 375 function wfCgiToArray( $query ) {
 376         if ( isset( $query[0] ) && $query[0] == '?' ) {
 377                 $query = substr( $query, 1 );
 378         }
 379         $bits = explode( '&', $query );
 380         $ret = array();
 381         foreach ( $bits as $bit ) {
 382                 if ( $bit === '' ) {
 383                         continue;
 384                 }
 385                 list( $key, $value ) = explode( '=', $bit );
 386                 $key = urldecode( $key );
 387                 $value = urldecode( $value );
 388                 if ( strpos( $key, '[' ) !== false ) {
 389                         $keys = array_reverse( explode( '[', $key ) );
 390                         $key = array_pop( $keys );
 391                         $temp = $value;
 392                         foreach ( $keys as $k ) {
 393                                 $k = substr( $k, 0, -1 );
 394                                 $temp = array( $k => $temp );
 395                         }
 396                         if ( isset( $ret[$key] ) ) {
 397                                 $ret[$key] = array_merge( $ret[$key], $temp );
 398                         } else {
 399                                 $ret[$key] = $temp;
 400                         }
 401                 } else {
 402                         $ret[$key] = $value;
 403                 }
 404         }
 405         return $ret;
 406 }
 407
 408 /**
 409  * Append a query string to an existing URL, which may or may not already
 410  * have query string parameters already. If so, they will be combined.
 411  *
 412  * @param $url String
 413  * @param $query Mixed: string or associative array
 414  * @return string
 415  */
 416 function wfAppendQuery( $url, $query ) {
 417         if ( is_array( $query ) ) {
 418                 $query = wfArrayToCGI( $query );
 419         }
 420         if( $query != '' ) {
 421                 if( false === strpos( $url, '?' ) ) {
 422                         $url .= '?';
 423                 } else {
 424                         $url .= '&';
 425                 }
 426                 $url .= $query;
 427         }
 428         return $url;
 429 }
 430
 431 /**
 432  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 433  * is correct.
 434  *
 435  * The meaning of the PROTO_* constants is as follows:
 436  * PROTO_HTTP: Output a URL starting with http://
 437  * PROTO_HTTPS: Output a URL starting with https://
 438  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 439  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 440  *
 441  * @todo this won't work with current-path-relative URLs
 442  * like "subdir/foo.html", etc.
 443  *
 444  * @param $url String: either fully-qualified or a local path + query
 445  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the protocol to use if $url or $wgServer is protocol-relative
 446  * @return string Fully-qualified URL
 447  */
 448 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 449         global $wgServer;
 450         if ( $defaultProto === PROTO_CURRENT ) {
 451                 $defaultProto = WebRequest::detectProtocol() . '://';
 452         }
 453
 454         // Analyze $wgServer to obtain its protocol
 455         $bits = wfParseUrl( $wgServer );
 456         $serverHasProto = $bits && $bits['scheme'] != '';
 457         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 458
 459         if( substr( $url, 0, 2 ) == '//' ) {
 460                 return $defaultProtoWithoutSlashes . $url;
 461         } elseif( substr( $url, 0, 1 ) == '/' ) {
 462                 // If $wgServer is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 463                 return ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $wgServer . $url;
 464         } else {
 465                 return $url;
 466         }
 467 }
 468
 469 /**
 470  * Returns a regular expression of url protocols
 471  *
 472  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 473  *        DO NOT USE this directy, use wfUrlProtocolsWithoutProtRel() instead
 474  * @return String
 475  */
 476 function wfUrlProtocols( $includeProtocolRelative = true ) {
 477         global $wgUrlProtocols;
 478
 479         // Cache return values separately based on $includeProtocolRelative
 480         static $retval = array( true => null, false => null );
 481         if ( !is_null( $retval[$includeProtocolRelative] ) ) {
 482                 return $retval[$includeProtocolRelative];
 483         }
 484
 485         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 486         // with LocalSettings files from 1.5
 487         if ( is_array( $wgUrlProtocols ) ) {
 488                 $protocols = array();
 489                 foreach ( $wgUrlProtocols as $protocol ) {
 490                         // Filter out '//' if !$includeProtocolRelative
 491                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 492                                 $protocols[] = preg_quote( $protocol, '/' );
 493                         }
 494                 }
 495
 496                 $retval[$includeProtocolRelative] = implode( '|', $protocols );
 497         } else {
 498                 // Ignore $includeProtocolRelative in this case
 499                 // This case exists for pre-1.6 compatibility, and we can safely assume
 500                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 501                 // URLs weren't supported until 1.18
 502                 $retval[$includeProtocolRelative] = $wgUrlProtocols;
 503         }
 504         return $retval[$includeProtocolRelative];
 505 }
 506
 507 /**
 508  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 509  * you need a regex that matches all URL protocols but does not match protocol-
 510  * relative URLs
 511  */
 512 function wfUrlProtocolsWithoutProtRel() {
 513         return wfUrlProtocols( false );
 514 }
 515
 516 /**
 517  * parse_url() work-alike, but non-broken.  Differences:
 518  *
 519  * 1) Does not raise warnings on bad URLs (just returns false)
 520  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 521  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 522  *
 523  * @param $url String: a URL to parse
 524  * @return Array: bits of the URL in an associative array, per PHP docs
 525  */
 526 function wfParseUrl( $url ) {
 527         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 528
 529         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 530         // way to handle them is to just prepend 'http:' and strip the protocol out later
 531         $wasRelative = substr( $url, 0, 2 ) == '//';
 532         if ( $wasRelative ) {
 533                 $url = "http:$url";
 534         }
 535         wfSuppressWarnings();
 536         $bits = parse_url( $url );
 537         wfRestoreWarnings();
 538         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 539         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 540         if ( !$bits || !isset( $bits['scheme'] ) ) {
 541                 return false;
 542         }
 543
 544         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 545         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 546                 $bits['delimiter'] = '://';
 547         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 548                 $bits['delimiter'] = ':';
 549                 // parse_url detects for news: and mailto: the host part of an url as path
 550                 // We have to correct this wrong detection
 551                 if ( isset( $bits['path'] ) ) {
 552                         $bits['host'] = $bits['path'];
 553                         $bits['path'] = '';
 554                 }
 555         } else {
 556                 return false;
 557         }
 558
 559         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 560         if ( !isset( $bits['host'] ) ) {
 561                 $bits['host'] = '';
 562
 563                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 564                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 565                         $bits['path'] = '/' . $bits['path'];
 566                 }
 567         }
 568
 569         // If the URL was protocol-relative, fix scheme and delimiter
 570         if ( $wasRelative ) {
 571                 $bits['scheme'] = '';
 572                 $bits['delimiter'] = '//';
 573         }
 574         return $bits;
 575 }
 576
 577 /**
 578  * Make a URL index, appropriate for the el_index field of externallinks.
 579  *
 580  * @param $url String
 581  * @return String
 582  */
 583 function wfMakeUrlIndex( $url ) {
 584         $bits = wfParseUrl( $url );
 585
 586         // Reverse the labels in the hostname, convert to lower case
 587         // For emails reverse domainpart only
 588         if ( $bits['scheme'] == 'mailto' ) {
 589                 $mailparts = explode( '@', $bits['host'], 2 );
 590                 if ( count( $mailparts ) === 2 ) {
 591                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 592                 } else {
 593                         // No domain specified, don't mangle it
 594                         $domainpart = '';
 595                 }
 596                 $reversedHost = $domainpart . '@' . $mailparts[0];
 597         } else {
 598                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 599         }
 600         // Add an extra dot to the end
 601         // Why? Is it in wrong place in mailto links?
 602         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 603                 $reversedHost .= '.';
 604         }
 605         // Reconstruct the pseudo-URL
 606         $prot = $bits['scheme'];
 607         $index = $prot . $bits['delimiter'] . $reversedHost;
 608         // Leave out user and password. Add the port, path, query and fragment
 609         if ( isset( $bits['port'] ) ) {
 610                 $index .= ':' . $bits['port'];
 611         }
 612         if ( isset( $bits['path'] ) ) {
 613                 $index .= $bits['path'];
 614         } else {
 615                 $index .= '/';
 616         }
 617         if ( isset( $bits['query'] ) ) {
 618                 $index .= '?' . $bits['query'];
 619         }
 620         if ( isset( $bits['fragment'] ) ) {
 621                 $index .= '#' . $bits['fragment'];
 622         }
 623         return $index;
 624 }
 625
 626 /**
 627  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 628  * In normal operation this is a NOP.
 629  *
 630  * Controlling globals:
 631  * $wgDebugLogFile - points to the log file
 632  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 633  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 634  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 635  *
 636  * @param $text String
 637  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 638  */
 639 function wfDebug( $text, $logonly = false ) {
 640         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 641         global $wgDebugLogPrefix, $wgShowDebug;
 642
 643         static $cache = array(); // Cache of unoutputted messages
 644         $text = wfDebugTimer() . $text;
 645
 646         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 647                 return;
 648         }
 649
 650         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 651                 $cache[] = $text;
 652
 653                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 654                         // add the message and any cached messages to the output
 655                         array_map( array( $wgOut, 'debug' ), $cache );
 656                         $cache = array();
 657                 }
 658         }
 659         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 660                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 661                         # Strip unprintables; they can switch terminal modes when binary data
 662                         # gets dumped, which is pretty annoying.
 663                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 664                         $text = $wgDebugLogPrefix . $text;
 665                         wfErrorLog( $text, $wgDebugLogFile );
 666                 }
 667         }
 668 }
 669
 670 /**
 671  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 672  */
 673 function wfIsDebugRawPage() {
 674         static $cache;
 675         if ( $cache !== null ) {
 676                 return $cache;
 677         }
 678         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 679         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 680                 || (
 681                         isset( $_SERVER['SCRIPT_NAME'] )
 682                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 683                 ) )
 684         {
 685                 $cache = true;
 686         } else {
 687                 $cache = false;
 688         }
 689         return $cache;
 690 }
 691
 692 /**
 693  * Get microsecond timestamps for debug logs
 694  *
 695  * @return string
 696  */
 697 function wfDebugTimer() {
 698         global $wgDebugTimestamps;
 699         if ( !$wgDebugTimestamps ) {
 700                 return '';
 701         }
 702         static $start = null;
 703
 704         if ( $start === null ) {
 705                 $start = microtime( true );
 706                 $prefix = "\n$start";
 707         } else {
 708                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 709         }
 710
 711         return $prefix . '  ';
 712 }
 713
 714 /**
 715  * Send a line giving PHP memory usage.
 716  *
 717  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 718  */
 719 function wfDebugMem( $exact = false ) {
 720         $mem = memory_get_usage();
 721         if( !$exact ) {
 722                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 723         } else {
 724                 $mem .= ' bytes';
 725         }
 726         wfDebug( "Memory usage: $mem\n" );
 727 }
 728
 729 /**
 730  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 731  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 732  *
 733  * @param $logGroup String
 734  * @param $text String
 735  * @param $public Bool: whether to log the event in the public log if no private
 736  *                     log file is specified, (default true)
 737  */
 738 function wfDebugLog( $logGroup, $text, $public = true ) {
 739         global $wgDebugLogGroups, $wgShowHostnames;
 740         $text = trim( $text ) . "\n";
 741         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 742                 $time = wfTimestamp( TS_DB );
 743                 $wiki = wfWikiID();
 744                 if ( $wgShowHostnames ) {
 745                         $host = wfHostname();
 746                 } else {
 747                         $host = '';
 748                 }
 749                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 750                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 751                 }
 752         } elseif ( $public === true ) {
 753                 wfDebug( $text, true );
 754         }
 755 }
 756
 757 /**
 758  * Log for database errors
 759  *
 760  * @param $text String: database error message.
 761  */
 762 function wfLogDBError( $text ) {
 763         global $wgDBerrorLog, $wgDBname;
 764         if ( $wgDBerrorLog ) {
 765                 $host = trim(`hostname`);
 766                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 767                 wfErrorLog( $text, $wgDBerrorLog );
 768         }
 769 }
 770
 771 /**
 772  * Log to a file without getting "file size exceeded" signals.
 773  *
 774  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 775  * send lines to the specified port, prefixed by the specified prefix and a space.
 776  *
 777  * @param $text String
 778  * @param $file String filename
 779  */
 780 function wfErrorLog( $text, $file ) {
 781         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 782                 # Needs the sockets extension
 783                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 784                         // IPv6 bracketed host
 785                         $host = $m[2];
 786                         $port = intval( $m[3] );
 787                         $prefix = isset( $m[4] ) ? $m[4] : false;
 788                         $domain = AF_INET6;
 789                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 790                         $host = $m[2];
 791                         if ( !IP::isIPv4( $host ) ) {
 792                                 $host = gethostbyname( $host );
 793                         }
 794                         $port = intval( $m[3] );
 795                         $prefix = isset( $m[4] ) ? $m[4] : false;
 796                         $domain = AF_INET;
 797                 } else {
 798                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 799                 }
 800
 801                 // Clean it up for the multiplexer
 802                 if ( strval( $prefix ) !== '' ) {
 803                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 804
 805                         // Limit to 64KB
 806                         if ( strlen( $text ) > 65534 ) {
 807                                 $text = substr( $text, 0, 65534 );
 808                         }
 809
 810                         if ( substr( $text, -1 ) != "\n" ) {
 811                                 $text .= "\n";
 812                         }
 813                 } elseif ( strlen( $text ) > 65535 ) {
 814                         $text = substr( $text, 0, 65535 );
 815                 }
 816
 817                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 818                 if ( !$sock ) {
 819                         return;
 820                 }
 821                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 822                 socket_close( $sock );
 823         } else {
 824                 wfSuppressWarnings();
 825                 $exists = file_exists( $file );
 826                 $size = $exists ? filesize( $file ) : false;
 827                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 828                         file_put_contents( $file, $text, FILE_APPEND );
 829                 }
 830                 wfRestoreWarnings();
 831         }
 832 }
 833
 834 /**
 835  * @todo document
 836  */
 837 function wfLogProfilingData() {
 838         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 839         global $wgProfileLimit, $wgUser;
 840
 841         $profiler = Profiler::instance();
 842
 843         # Profiling must actually be enabled...
 844         if ( $profiler->isStub() ) {
 845                 return;
 846         }
 847
 848         // Get total page request time and only show pages that longer than
 849         // $wgProfileLimit time (default is 0)
 850         $now = wfTime();
 851         $elapsed = $now - $wgRequestTime;
 852         if ( $elapsed <= $wgProfileLimit ) {
 853                 return;
 854         }
 855
 856         $profiler->logData();
 857
 858         // Check whether this should be logged in the debug file.
 859         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 860                 return;
 861         }
 862
 863         $forward = '';
 864         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 865                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 866         }
 867         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 868                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 869         }
 870         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 871                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 872         }
 873         if ( $forward ) {
 874                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 875         }
 876         // Don't load $wgUser at this late stage just for statistics purposes
 877         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 878         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 879                 $forward .= ' anon';
 880         }
 881         $log = sprintf( "%s\t%04.3f\t%s\n",
 882                 gmdate( 'YmdHis' ), $elapsed,
 883                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 884
 885         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 886 }
 887
 888 /**
 889  * Check if the wiki read-only lock file is present. This can be used to lock
 890  * off editing functions, but doesn't guarantee that the database will not be
 891  * modified.
 892  *
 893  * @return bool
 894  */
 895 function wfReadOnly() {
 896         global $wgReadOnlyFile, $wgReadOnly;
 897
 898         if ( !is_null( $wgReadOnly ) ) {
 899                 return (bool)$wgReadOnly;
 900         }
 901         if ( $wgReadOnlyFile == '' ) {
 902                 return false;
 903         }
 904         // Set $wgReadOnly for faster access next time
 905         if ( is_file( $wgReadOnlyFile ) ) {
 906                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 907         } else {
 908                 $wgReadOnly = false;
 909         }
 910         return (bool)$wgReadOnly;
 911 }
 912
 913 function wfReadOnlyReason() {
 914         global $wgReadOnly;
 915         wfReadOnly();
 916         return $wgReadOnly;
 917 }
 918
 919 /**
 920  * Return a Language object from $langcode
 921  *
 922  * @param $langcode Mixed: either:
 923  *                  - a Language object
 924  *                  - code of the language to get the message for, if it is
 925  *                    a valid code create a language for that language, if
 926  *                    it is a string but not a valid code then make a basic
 927  *                    language object
 928  *                  - a boolean: if it's false then use the current users
 929  *                    language (as a fallback for the old parameter
 930  *                    functionality), or if it is true then use the wikis
 931  * @return Language object
 932  */
 933 function wfGetLangObj( $langcode = false ) {
 934         # Identify which language to get or create a language object for.
 935         # Using is_object here due to Stub objects.
 936         if( is_object( $langcode ) ) {
 937                 # Great, we already have the object (hopefully)!
 938                 return $langcode;
 939         }
 940
 941         global $wgContLang, $wgLanguageCode;
 942         if( $langcode === true || $langcode === $wgLanguageCode ) {
 943                 # $langcode is the language code of the wikis content language object.
 944                 # or it is a boolean and value is true
 945                 return $wgContLang;
 946         }
 947
 948         global $wgLang;
 949         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 950                 # $langcode is the language code of user language object.
 951                 # or it was a boolean and value is false
 952                 return $wgLang;
 953         }
 954
 955         $validCodes = array_keys( Language::getLanguageNames() );
 956         if( in_array( $langcode, $validCodes ) ) {
 957                 # $langcode corresponds to a valid language.
 958                 return Language::factory( $langcode );
 959         }
 960
 961         # $langcode is a string, but not a valid language code; use content language.
 962         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 963         return $wgContLang;
 964 }
 965
 966 /**
 967  * Old function when $wgBetterDirectionality existed
 968  * Removed in core, kept in extensions for backwards compat.
 969  *
 970  * @deprecated since 1.18
 971  * @return Language
 972  */
 973 function wfUILang() {
 974         global $wgLang;
 975         return $wgLang;
 976 }
 977
 978 /**
 979  * This is the new function for getting translated interface messages.
 980  * See the Message class for documentation how to use them.
 981  * The intention is that this function replaces all old wfMsg* functions.
 982  * @param $key \string Message key.
 983  * Varargs: normal message parameters.
 984  * @return Message
 985  * @since 1.17
 986  */
 987 function wfMessage( $key /*...*/) {
 988         $params = func_get_args();
 989         array_shift( $params );
 990         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 991                 $params = $params[0];
 992         }
 993         return new Message( $key, $params );
 994 }
 995
 996 /**
 997  * This function accepts multiple message keys and returns a message instance
 998  * for the first message which is non-empty. If all messages are empty then an
 999  * instance of the first message key is returned.
1000  * @param varargs: message keys
1001  * @return Message
1002  * @since 1.18
1003  */
1004 function wfMessageFallback( /*...*/ ) {
1005         $args = func_get_args();
1006         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1007 }
1008
1009 /**
1010  * Get a message from anywhere, for the current user language.
1011  *
1012  * Use wfMsgForContent() instead if the message should NOT
1013  * change depending on the user preferences.
1014  *
1015  * @param $key String: lookup key for the message, usually
1016  *    defined in languages/Language.php
1017  *
1018  * Parameters to the message, which can be used to insert variable text into
1019  * it, can be passed to this function in the following formats:
1020  * - One per argument, starting at the second parameter
1021  * - As an array in the second parameter
1022  * These are not shown in the function definition.
1023  *
1024  * @return String
1025  */
1026 function wfMsg( $key ) {
1027         $args = func_get_args();
1028         array_shift( $args );
1029         return wfMsgReal( $key, $args );
1030 }
1031
1032 /**
1033  * Same as above except doesn't transform the message
1034  *
1035  * @param $key String
1036  * @return String
1037  */
1038 function wfMsgNoTrans( $key ) {
1039         $args = func_get_args();
1040         array_shift( $args );
1041         return wfMsgReal( $key, $args, true, false, false );
1042 }
1043
1044 /**
1045  * Get a message from anywhere, for the current global language
1046  * set with $wgLanguageCode.
1047  *
1048  * Use this if the message should NOT change dependent on the
1049  * language set in the user's preferences. This is the case for
1050  * most text written into logs, as well as link targets (such as
1051  * the name of the copyright policy page). Link titles, on the
1052  * other hand, should be shown in the UI language.
1053  *
1054  * Note that MediaWiki allows users to change the user interface
1055  * language in their preferences, but a single installation
1056  * typically only contains content in one language.
1057  *
1058  * Be wary of this distinction: If you use wfMsg() where you should
1059  * use wfMsgForContent(), a user of the software may have to
1060  * customize potentially hundreds of messages in
1061  * order to, e.g., fix a link in every possible language.
1062  *
1063  * @param $key String: lookup key for the message, usually
1064  *     defined in languages/Language.php
1065  * @return String
1066  */
1067 function wfMsgForContent( $key ) {
1068         global $wgForceUIMsgAsContentMsg;
1069         $args = func_get_args();
1070         array_shift( $args );
1071         $forcontent = true;
1072         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1073                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1074         {
1075                 $forcontent = false;
1076         }
1077         return wfMsgReal( $key, $args, true, $forcontent );
1078 }
1079
1080 /**
1081  * Same as above except doesn't transform the message
1082  *
1083  * @param $key String
1084  * @return String
1085  */
1086 function wfMsgForContentNoTrans( $key ) {
1087         global $wgForceUIMsgAsContentMsg;
1088         $args = func_get_args();
1089         array_shift( $args );
1090         $forcontent = true;
1091         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1092                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1093         {
1094                 $forcontent = false;
1095         }
1096         return wfMsgReal( $key, $args, true, $forcontent, false );
1097 }
1098
1099 /**
1100  * Really get a message
1101  *
1102  * @param $key String: key to get.
1103  * @param $args
1104  * @param $useDB Boolean
1105  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1106  * @param $transform Boolean: Whether or not to transform the message.
1107  * @return String: the requested message.
1108  */
1109 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1110         wfProfileIn( __METHOD__ );
1111         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1112         $message = wfMsgReplaceArgs( $message, $args );
1113         wfProfileOut( __METHOD__ );
1114         return $message;
1115 }
1116
1117 /**
1118  * Fetch a message string value, but don't replace any keys yet.
1119  *
1120  * @param $key String
1121  * @param $useDB Bool
1122  * @param $langCode String: Code of the language to get the message for, or
1123  *                  behaves as a content language switch if it is a boolean.
1124  * @param $transform Boolean: whether to parse magic words, etc.
1125  * @return string
1126  */
1127 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1128         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1129
1130         $cache = MessageCache::singleton();
1131         $message = $cache->get( $key, $useDB, $langCode );
1132         if( $message === false ) {
1133                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1134         } elseif ( $transform ) {
1135                 $message = $cache->transform( $message );
1136         }
1137         return $message;
1138 }
1139
1140 /**
1141  * Replace message parameter keys on the given formatted output.
1142  *
1143  * @param $message String
1144  * @param $args Array
1145  * @return string
1146  * @private
1147  */
1148 function wfMsgReplaceArgs( $message, $args ) {
1149         # Fix windows line-endings
1150         # Some messages are split with explode("\n", $msg)
1151         $message = str_replace( "\r", '', $message );
1152
1153         // Replace arguments
1154         if ( count( $args ) ) {
1155                 if ( is_array( $args[0] ) ) {
1156                         $args = array_values( $args[0] );
1157                 }
1158                 $replacementKeys = array();
1159                 foreach( $args as $n => $param ) {
1160                         $replacementKeys['$' . ( $n + 1 )] = $param;
1161                 }
1162                 $message = strtr( $message, $replacementKeys );
1163         }
1164
1165         return $message;
1166 }
1167
1168 /**
1169  * Return an HTML-escaped version of a message.
1170  * Parameter replacements, if any, are done *after* the HTML-escaping,
1171  * so parameters may contain HTML (eg links or form controls). Be sure
1172  * to pre-escape them if you really do want plaintext, or just wrap
1173  * the whole thing in htmlspecialchars().
1174  *
1175  * @param $key String
1176  * @param string ... parameters
1177  * @return string
1178  */
1179 function wfMsgHtml( $key ) {
1180         $args = func_get_args();
1181         array_shift( $args );
1182         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1183 }
1184
1185 /**
1186  * Return an HTML version of message
1187  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1188  * so parameters may contain HTML (eg links or form controls). Be sure
1189  * to pre-escape them if you really do want plaintext, or just wrap
1190  * the whole thing in htmlspecialchars().
1191  *
1192  * @param $key String
1193  * @param string ... parameters
1194  * @return string
1195  */
1196 function wfMsgWikiHtml( $key ) {
1197         $args = func_get_args();
1198         array_shift( $args );
1199         return wfMsgReplaceArgs(
1200                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1201                 /* can't be set to false */ true, /* interface */ true )->getText(),
1202                 $args );
1203 }
1204
1205 /**
1206  * Returns message in the requested format
1207  * @param $key String: key of the message
1208  * @param $options Array: processing rules. Can take the following options:
1209  *   <i>parse</i>: parses wikitext to HTML
1210  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1211  *       p's added by parser or tidy
1212  *   <i>escape</i>: filters message through htmlspecialchars
1213  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1214  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1215  *   <i>parsemag</i>: transform the message using magic phrases
1216  *   <i>content</i>: fetch message for content language instead of interface
1217  * Also can accept a single associative argument, of the form 'language' => 'xx':
1218  *   <i>language</i>: Language object or language code to fetch message for
1219  *       (overriden by <i>content</i>).
1220  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1221  *
1222  * @return String
1223  */
1224 function wfMsgExt( $key, $options ) {
1225         $args = func_get_args();
1226         array_shift( $args );
1227         array_shift( $args );
1228         $options = (array)$options;
1229
1230         foreach( $options as $arrayKey => $option ) {
1231                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1232                         # An unknown index, neither numeric nor "language"
1233                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1234                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1235                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1236                 'replaceafter', 'parsemag', 'content' ) ) ) {
1237                         # A numeric index with unknown value
1238                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1239                 }
1240         }
1241
1242         if( in_array( 'content', $options, true ) ) {
1243                 $forContent = true;
1244                 $langCode = true;
1245                 $langCodeObj = null;
1246         } elseif( array_key_exists( 'language', $options ) ) {
1247                 $forContent = false;
1248                 $langCode = wfGetLangObj( $options['language'] );
1249                 $langCodeObj = $langCode;
1250         } else {
1251                 $forContent = false;
1252                 $langCode = false;
1253                 $langCodeObj = null;
1254         }
1255
1256         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1257
1258         if( !in_array( 'replaceafter', $options, true ) ) {
1259                 $string = wfMsgReplaceArgs( $string, $args );
1260         }
1261
1262         $messageCache = MessageCache::singleton();
1263         if( in_array( 'parse', $options, true ) ) {
1264                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1265         } elseif ( in_array( 'parseinline', $options, true ) ) {
1266                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1267                 $m = array();
1268                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1269                         $string = $m[1];
1270                 }
1271         } elseif ( in_array( 'parsemag', $options, true ) ) {
1272                 $string = $messageCache->transform( $string,
1273                                 !$forContent, $langCodeObj );
1274         }
1275
1276         if ( in_array( 'escape', $options, true ) ) {
1277                 $string = htmlspecialchars ( $string );
1278         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1279                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1280         }
1281
1282         if( in_array( 'replaceafter', $options, true ) ) {
1283                 $string = wfMsgReplaceArgs( $string, $args );
1284         }
1285
1286         return $string;
1287 }
1288
1289 /**
1290  * Since wfMsg() and co suck, they don't return false if the message key they
1291  * looked up didn't exist but a XHTML string, this function checks for the
1292  * nonexistance of messages by checking the MessageCache::get() result directly.
1293  *
1294  * @param $key      String: the message key looked up
1295  * @return Boolean True if the message *doesn't* exist.
1296  */
1297 function wfEmptyMsg( $key ) {
1298         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1299 }
1300
1301 /**
1302  * Throw a debugging exception. This function previously once exited the process,
1303  * but now throws an exception instead, with similar results.
1304  *
1305  * @param $msg String: message shown when dieing.
1306  */
1307 function wfDebugDieBacktrace( $msg = '' ) {
1308         throw new MWException( $msg );
1309 }
1310
1311 /**
1312  * Fetch server name for use in error reporting etc.
1313  * Use real server name if available, so we know which machine
1314  * in a server farm generated the current page.
1315  *
1316  * @return string
1317  */
1318 function wfHostname() {
1319         static $host;
1320         if ( is_null( $host ) ) {
1321                 if ( function_exists( 'posix_uname' ) ) {
1322                         // This function not present on Windows
1323                         $uname = posix_uname();
1324                 } else {
1325                         $uname = false;
1326                 }
1327                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1328                         $host = $uname['nodename'];
1329                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1330                         # Windows computer name
1331                         $host = getenv( 'COMPUTERNAME' );
1332                 } else {
1333                         # This may be a virtual server.
1334                         $host = $_SERVER['SERVER_NAME'];
1335                 }
1336         }
1337         return $host;
1338 }
1339
1340 /**
1341  * Returns a HTML comment with the elapsed time since request.
1342  * This method has no side effects.
1343  *
1344  * @return string
1345  */
1346 function wfReportTime() {
1347         global $wgRequestTime, $wgShowHostnames;
1348
1349         $now = wfTime();
1350         $elapsed = $now - $wgRequestTime;
1351
1352         return $wgShowHostnames
1353                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1354                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1355 }
1356
1357 /**
1358  * Safety wrapper for debug_backtrace().
1359  *
1360  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1361  * murky circumstances, which may be triggered in part by stub objects
1362  * or other fancy talkin'.
1363  *
1364  * Will return an empty array if Zend Optimizer is detected or if
1365  * debug_backtrace is disabled, otherwise the output from
1366  * debug_backtrace() (trimmed).
1367  *
1368  * @return array of backtrace information
1369  */
1370 function wfDebugBacktrace( $limit = 0 ) {
1371         static $disabled = null;
1372
1373         if( extension_loaded( 'Zend Optimizer' ) ) {
1374                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1375                 return array();
1376         }
1377
1378         if ( is_null( $disabled ) ) {
1379                 $disabled = false;
1380                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1381                 $functions = array_map( 'trim', $functions );
1382                 $functions = array_map( 'strtolower', $functions );
1383                 if ( in_array( 'debug_backtrace', $functions ) ) {
1384                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1385                         $disabled = true;
1386                 }
1387         }
1388         if ( $disabled ) {
1389                 return array();
1390         }
1391
1392         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1393                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1394         } else {
1395                 return array_slice( debug_backtrace(), 1 );
1396         }
1397 }
1398
1399 /**
1400  * Get a debug backtrace as a string
1401  *
1402  * @return string
1403  */
1404 function wfBacktrace() {
1405         global $wgCommandLineMode;
1406
1407         if ( $wgCommandLineMode ) {
1408                 $msg = '';
1409         } else {
1410                 $msg = "<ul>\n";
1411         }
1412         $backtrace = wfDebugBacktrace();
1413         foreach( $backtrace as $call ) {
1414                 if( isset( $call['file'] ) ) {
1415                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1416                         $file = $f[count( $f ) - 1];
1417                 } else {
1418                         $file = '-';
1419                 }
1420                 if( isset( $call['line'] ) ) {
1421                         $line = $call['line'];
1422                 } else {
1423                         $line = '-';
1424                 }
1425                 if ( $wgCommandLineMode ) {
1426                         $msg .= "$file line $line calls ";
1427                 } else {
1428                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1429                 }
1430                 if( !empty( $call['class'] ) ) {
1431                         $msg .= $call['class'] . $call['type'];
1432                 }
1433                 $msg .= $call['function'] . '()';
1434
1435                 if ( $wgCommandLineMode ) {
1436                         $msg .= "\n";
1437                 } else {
1438                         $msg .= "</li>\n";
1439                 }
1440         }
1441         if ( $wgCommandLineMode ) {
1442                 $msg .= "\n";
1443         } else {
1444                 $msg .= "</ul>\n";
1445         }
1446
1447         return $msg;
1448 }
1449
1450 /**
1451  * Get the name of the function which called this function
1452  *
1453  * @param $level Int
1454  * @return Bool|string
1455  */
1456 function wfGetCaller( $level = 2 ) {
1457         $backtrace = wfDebugBacktrace( $level );
1458         if ( isset( $backtrace[$level] ) ) {
1459                 return wfFormatStackFrame( $backtrace[$level] );
1460         } else {
1461                 $caller = 'unknown';
1462         }
1463         return $caller;
1464 }
1465
1466 /**
1467  * Return a string consisting of callers in the stack. Useful sometimes
1468  * for profiling specific points.
1469  *
1470  * @param $limit The maximum depth of the stack frame to return, or false for
1471  *               the entire stack.
1472  * @return String
1473  */
1474 function wfGetAllCallers( $limit = 3 ) {
1475         $trace = array_reverse( wfDebugBacktrace() );
1476         if ( !$limit || $limit > count( $trace ) - 1 ) {
1477                 $limit = count( $trace ) - 1;
1478         }
1479         $trace = array_slice( $trace, -$limit - 1, $limit );
1480         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1481 }
1482
1483 /**
1484  * Return a string representation of frame
1485  *
1486  * @param $frame Array
1487  * @return Bool
1488  */
1489 function wfFormatStackFrame( $frame ) {
1490         return isset( $frame['class'] ) ?
1491                 $frame['class'] . '::' . $frame['function'] :
1492                 $frame['function'];
1493 }
1494
1495
1496 /* Some generic result counters, pulled out of SearchEngine */
1497
1498
1499 /**
1500  * @todo document
1501  *
1502  * @param $offset Int
1503  * @param $limit Int
1504  * @return String
1505  */
1506 function wfShowingResults( $offset, $limit ) {
1507         global $wgLang;
1508         return wfMsgExt(
1509                 'showingresults',
1510                 array( 'parseinline' ),
1511                 $wgLang->formatNum( $limit ),
1512                 $wgLang->formatNum( $offset + 1 )
1513         );
1514 }
1515
1516 /**
1517  * Generate (prev x| next x) (20|50|100...) type links for paging
1518  *
1519  * @param $offset String
1520  * @param $limit Integer
1521  * @param $link String
1522  * @param $query String: optional URL query parameter string
1523  * @param $atend Bool: optional param for specified if this is the last page
1524  * @return String
1525  */
1526 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1527         global $wgLang;
1528         $fmtLimit = $wgLang->formatNum( $limit );
1529         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1530         # Get prev/next link display text
1531         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1532         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1533         # Get prev/next link title text
1534         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1535         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1536         # Fetch the title object
1537         if( is_object( $link ) ) {
1538                 $title =& $link;
1539         } else {
1540                 $title = Title::newFromText( $link );
1541                 if( is_null( $title ) ) {
1542                         return false;
1543                 }
1544         }
1545         # Make 'previous' link
1546         if( 0 != $offset ) {
1547                 $po = $offset - $limit;
1548                 $po = max( $po, 0 );
1549                 $q = "limit={$limit}&offset={$po}";
1550                 if( $query != '' ) {
1551                         $q .= '&' . $query;
1552                 }
1553                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1554         } else {
1555                 $plink = $prev;
1556         }
1557         # Make 'next' link
1558         $no = $offset + $limit;
1559         $q = "limit={$limit}&offset={$no}";
1560         if( $query != '' ) {
1561                 $q .= '&' . $query;
1562         }
1563         if( $atend ) {
1564                 $nlink = $next;
1565         } else {
1566                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1567         }
1568         # Make links to set number of items per page
1569         $nums = $wgLang->pipeList( array(
1570                 wfNumLink( $offset, 20, $title, $query ),
1571                 wfNumLink( $offset, 50, $title, $query ),
1572                 wfNumLink( $offset, 100, $title, $query ),
1573                 wfNumLink( $offset, 250, $title, $query ),
1574                 wfNumLink( $offset, 500, $title, $query )
1575         ) );
1576         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1577 }
1578
1579 /**
1580  * Generate links for (20|50|100...) items-per-page links
1581  *
1582  * @param $offset String
1583  * @param $limit Integer
1584  * @param $title Title
1585  * @param $query String: optional URL query parameter string
1586  */
1587 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1588         global $wgLang;
1589         if( $query == '' ) {
1590                 $q = '';
1591         } else {
1592                 $q = $query.'&';
1593         }
1594         $q .= "limit={$limit}&offset={$offset}";
1595         $fmtLimit = $wgLang->formatNum( $limit );
1596         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1597         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1598         return $s;
1599 }
1600
1601 /**
1602  * @todo document
1603  * @todo FIXME: We may want to blacklist some broken browsers
1604  *
1605  * @param $force Bool
1606  * @return bool Whereas client accept gzip compression
1607  */
1608 function wfClientAcceptsGzip( $force = false ) {
1609         static $result = null;
1610         if ( $result === null || $force ) {
1611                 $result = false;
1612                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1613                         # @todo FIXME: We may want to blacklist some broken browsers
1614                         $m = array();
1615                         if( preg_match(
1616                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1617                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1618                                 $m )
1619                         )
1620                         {
1621                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1622                                         $result = false;
1623                                         return $result;
1624                                 }
1625                                 wfDebug( " accepts gzip\n" );
1626                                 $result = true;
1627                         }
1628                 }
1629         }
1630         return $result;
1631 }
1632
1633 /**
1634  * Obtain the offset and limit values from the request string;
1635  * used in special pages
1636  *
1637  * @param $deflimit Int default limit if none supplied
1638  * @param $optionname String Name of a user preference to check against
1639  * @return array
1640  *
1641  */
1642 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1643         global $wgRequest;
1644         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1645 }
1646
1647 /**
1648  * Escapes the given text so that it may be output using addWikiText()
1649  * without any linking, formatting, etc. making its way through. This
1650  * is achieved by substituting certain characters with HTML entities.
1651  * As required by the callers, <nowiki> is not used.
1652  *
1653  * @param $text String: text to be escaped
1654  * @return String
1655  */
1656 function wfEscapeWikiText( $text ) {
1657         $text = strtr( "\n$text", array(
1658                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1659                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1660                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1661                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1662                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1663                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1664         ) );
1665         return substr( $text, 1 );
1666 }
1667
1668 /**
1669  * Get the current unix timetstamp with microseconds.  Useful for profiling
1670  * @return Float
1671  */
1672 function wfTime() {
1673         return microtime( true );
1674 }
1675
1676 /**
1677  * Sets dest to source and returns the original value of dest
1678  * If source is NULL, it just returns the value, it doesn't set the variable
1679  * If force is true, it will set the value even if source is NULL
1680  *
1681  * @param $dest Mixed
1682  * @param $source Mixed
1683  * @param $force Bool
1684  * @return Mixed
1685  */
1686 function wfSetVar( &$dest, $source, $force = false ) {
1687         $temp = $dest;
1688         if ( !is_null( $source ) || $force ) {
1689                 $dest = $source;
1690         }
1691         return $temp;
1692 }
1693
1694 /**
1695  * As for wfSetVar except setting a bit
1696  *
1697  * @param $dest Int
1698  * @param $bit Int
1699  * @param $state Bool
1700  */
1701 function wfSetBit( &$dest, $bit, $state = true ) {
1702         $temp = (bool)( $dest & $bit );
1703         if ( !is_null( $state ) ) {
1704                 if ( $state ) {
1705                         $dest |= $bit;
1706                 } else {
1707                         $dest &= ~$bit;
1708                 }
1709         }
1710         return $temp;
1711 }
1712
1713 /**
1714  * Windows-compatible version of escapeshellarg()
1715  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1716  * function puts single quotes in regardless of OS.
1717  *
1718  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1719  * earlier distro releases of PHP)
1720  *
1721  * @param varargs
1722  * @return String
1723  */
1724 function wfEscapeShellArg( ) {
1725         wfInitShellLocale();
1726
1727         $args = func_get_args();
1728         $first = true;
1729         $retVal = '';
1730         foreach ( $args as $arg ) {
1731                 if ( !$first ) {
1732                         $retVal .= ' ';
1733                 } else {
1734                         $first = false;
1735                 }
1736
1737                 if ( wfIsWindows() ) {
1738                         // Escaping for an MSVC-style command line parser and CMD.EXE
1739                         // Refs:
1740                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1741                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1742                         //  * Bug #13518
1743                         //  * CR r63214
1744                         // Double the backslashes before any double quotes. Escape the double quotes.
1745                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1746                         $arg = '';
1747                         $iteration = 0;
1748                         foreach ( $tokens as $token ) {
1749                                 if ( $iteration % 2 == 1 ) {
1750                                         // Delimiter, a double quote preceded by zero or more slashes
1751                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1752                                 } elseif ( $iteration % 4 == 2 ) {
1753                                         // ^ in $token will be outside quotes, need to be escaped
1754                                         $arg .= str_replace( '^', '^^', $token );
1755                                 } else { // $iteration % 4 == 0
1756                                         // ^ in $token will appear inside double quotes, so leave as is
1757                                         $arg .= $token;
1758                                 }
1759                                 $iteration++;
1760                         }
1761                         // Double the backslashes before the end of the string, because
1762                         // we will soon add a quote
1763                         $m = array();
1764                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1765                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1766                         }
1767
1768                         // Add surrounding quotes
1769                         $retVal .= '"' . $arg . '"';
1770                 } else {
1771                         $retVal .= escapeshellarg( $arg );
1772                 }
1773         }
1774         return $retVal;
1775 }
1776
1777 /**
1778  * wfMerge attempts to merge differences between three texts.
1779  * Returns true for a clean merge and false for failure or a conflict.
1780  *
1781  * @param $old String
1782  * @param $mine String
1783  * @param $yours String
1784  * @param $result String
1785  * @return Bool
1786  */
1787 function wfMerge( $old, $mine, $yours, &$result ) {
1788         global $wgDiff3;
1789
1790         # This check may also protect against code injection in
1791         # case of broken installations.
1792         wfSuppressWarnings();
1793         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1794         wfRestoreWarnings();
1795
1796         if( !$haveDiff3 ) {
1797                 wfDebug( "diff3 not found\n" );
1798                 return false;
1799         }
1800
1801         # Make temporary files
1802         $td = wfTempDir();
1803         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1804         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1805         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1806
1807         fwrite( $oldtextFile, $old );
1808         fclose( $oldtextFile );
1809         fwrite( $mytextFile, $mine );
1810         fclose( $mytextFile );
1811         fwrite( $yourtextFile, $yours );
1812         fclose( $yourtextFile );
1813
1814         # Check for a conflict
1815         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1816                 wfEscapeShellArg( $mytextName ) . ' ' .
1817                 wfEscapeShellArg( $oldtextName ) . ' ' .
1818                 wfEscapeShellArg( $yourtextName );
1819         $handle = popen( $cmd, 'r' );
1820
1821         if( fgets( $handle, 1024 ) ) {
1822                 $conflict = true;
1823         } else {
1824                 $conflict = false;
1825         }
1826         pclose( $handle );
1827
1828         # Merge differences
1829         $cmd = $wgDiff3 . ' -a -e --merge ' .
1830                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1831         $handle = popen( $cmd, 'r' );
1832         $result = '';
1833         do {
1834                 $data = fread( $handle, 8192 );
1835                 if ( strlen( $data ) == 0 ) {
1836                         break;
1837                 }
1838                 $result .= $data;
1839         } while ( true );
1840         pclose( $handle );
1841         unlink( $mytextName );
1842         unlink( $oldtextName );
1843         unlink( $yourtextName );
1844
1845         if ( $result === '' && $old !== '' && !$conflict ) {
1846                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1847                 $conflict = true;
1848         }
1849         return !$conflict;
1850 }
1851
1852 /**
1853  * Returns unified plain-text diff of two texts.
1854  * Useful for machine processing of diffs.
1855  *
1856  * @param $before String: the text before the changes.
1857  * @param $after String: the text after the changes.
1858  * @param $params String: command-line options for the diff command.
1859  * @return String: unified diff of $before and $after
1860  */
1861 function wfDiff( $before, $after, $params = '-u' ) {
1862         if ( $before == $after ) {
1863                 return '';
1864         }
1865
1866         global $wgDiff;
1867         wfSuppressWarnings();
1868         $haveDiff = $wgDiff && file_exists( $wgDiff );
1869         wfRestoreWarnings();
1870
1871         # This check may also protect against code injection in
1872         # case of broken installations.
1873         if( !$haveDiff ) {
1874                 wfDebug( "diff executable not found\n" );
1875                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1876                 $format = new UnifiedDiffFormatter();
1877                 return $format->format( $diffs );
1878         }
1879
1880         # Make temporary files
1881         $td = wfTempDir();
1882         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1883         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1884
1885         fwrite( $oldtextFile, $before );
1886         fclose( $oldtextFile );
1887         fwrite( $newtextFile, $after );
1888         fclose( $newtextFile );
1889
1890         // Get the diff of the two files
1891         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1892
1893         $h = popen( $cmd, 'r' );
1894
1895         $diff = '';
1896
1897         do {
1898                 $data = fread( $h, 8192 );
1899                 if ( strlen( $data ) == 0 ) {
1900                         break;
1901                 }
1902                 $diff .= $data;
1903         } while ( true );
1904
1905         // Clean up
1906         pclose( $h );
1907         unlink( $oldtextName );
1908         unlink( $newtextName );
1909
1910         // Kill the --- and +++ lines. They're not useful.
1911         $diff_lines = explode( "\n", $diff );
1912         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1913                 unset( $diff_lines[0] );
1914         }
1915         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1916                 unset( $diff_lines[1] );
1917         }
1918
1919         $diff = implode( "\n", $diff_lines );
1920
1921         return $diff;
1922 }
1923
1924 /**
1925  * A wrapper around the PHP function var_export().
1926  * Either print it or add it to the regular output ($wgOut).
1927  *
1928  * @param $var A PHP variable to dump.
1929  */
1930 function wfVarDump( $var ) {
1931         global $wgOut;
1932         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1933         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1934                 print $s;
1935         } else {
1936                 $wgOut->addHTML( $s );
1937         }
1938 }
1939
1940 /**
1941  * Provide a simple HTTP error.
1942  *
1943  * @param $code Int|String
1944  * @param $label String
1945  * @param $desc String
1946  */
1947 function wfHttpError( $code, $label, $desc ) {
1948         global $wgOut;
1949         $wgOut->disable();
1950         header( "HTTP/1.0 $code $label" );
1951         header( "Status: $code $label" );
1952         $wgOut->sendCacheControl();
1953
1954         header( 'Content-type: text/html; charset=utf-8' );
1955         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1956                 '<html><head><title>' .
1957                 htmlspecialchars( $label ) .
1958                 '</title></head><body><h1>' .
1959                 htmlspecialchars( $label ) .
1960                 '</h1><p>' .
1961                 nl2br( htmlspecialchars( $desc ) ) .
1962                 "</p></body></html>\n";
1963 }
1964
1965 /**
1966  * Clear away any user-level output buffers, discarding contents.
1967  *
1968  * Suitable for 'starting afresh', for instance when streaming
1969  * relatively large amounts of data without buffering, or wanting to
1970  * output image files without ob_gzhandler's compression.
1971  *
1972  * The optional $resetGzipEncoding parameter controls suppression of
1973  * the Content-Encoding header sent by ob_gzhandler; by default it
1974  * is left. See comments for wfClearOutputBuffers() for why it would
1975  * be used.
1976  *
1977  * Note that some PHP configuration options may add output buffer
1978  * layers which cannot be removed; these are left in place.
1979  *
1980  * @param $resetGzipEncoding Bool
1981  */
1982 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1983         if( $resetGzipEncoding ) {
1984                 // Suppress Content-Encoding and Content-Length
1985                 // headers from 1.10+s wfOutputHandler
1986                 global $wgDisableOutputCompression;
1987                 $wgDisableOutputCompression = true;
1988         }
1989         while( $status = ob_get_status() ) {
1990                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1991                         // Probably from zlib.output_compression or other
1992                         // PHP-internal setting which can't be removed.
1993                         //
1994                         // Give up, and hope the result doesn't break
1995                         // output behavior.
1996                         break;
1997                 }
1998                 if( !ob_end_clean() ) {
1999                         // Could not remove output buffer handler; abort now
2000                         // to avoid getting in some kind of infinite loop.
2001                         break;
2002                 }
2003                 if( $resetGzipEncoding ) {
2004                         if( $status['name'] == 'ob_gzhandler' ) {
2005                                 // Reset the 'Content-Encoding' field set by this handler
2006                                 // so we can start fresh.
2007                                 if ( function_exists( 'header_remove' ) ) {
2008                                         // Available since PHP 5.3.0
2009                                         header_remove( 'Content-Encoding' );
2010                                 } else {
2011                                         // We need to provide a valid content-coding. See bug 28069
2012                                         header( 'Content-Encoding: identity' );
2013                                 }
2014                                 break;
2015                         }
2016                 }
2017         }
2018 }
2019
2020 /**
2021  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2022  *
2023  * Clear away output buffers, but keep the Content-Encoding header
2024  * produced by ob_gzhandler, if any.
2025  *
2026  * This should be used for HTTP 304 responses, where you need to
2027  * preserve the Content-Encoding header of the real result, but
2028  * also need to suppress the output of ob_gzhandler to keep to spec
2029  * and avoid breaking Firefox in rare cases where the headers and
2030  * body are broken over two packets.
2031  */
2032 function wfClearOutputBuffers() {
2033         wfResetOutputBuffers( false );
2034 }
2035
2036 /**
2037  * Converts an Accept-* header into an array mapping string values to quality
2038  * factors
2039  *
2040  * @param $accept String
2041  * @param $def String default
2042  * @return Array
2043  */
2044 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2045         # No arg means accept anything (per HTTP spec)
2046         if( !$accept ) {
2047                 return array( $def => 1.0 );
2048         }
2049
2050         $prefs = array();
2051
2052         $parts = explode( ',', $accept );
2053
2054         foreach( $parts as $part ) {
2055                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2056                 $values = explode( ';', trim( $part ) );
2057                 $match = array();
2058                 if ( count( $values ) == 1 ) {
2059                         $prefs[$values[0]] = 1.0;
2060                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2061                         $prefs[$values[0]] = floatval( $match[1] );
2062                 }
2063         }
2064
2065         return $prefs;
2066 }
2067
2068 /**
2069  * Checks if a given MIME type matches any of the keys in the given
2070  * array. Basic wildcards are accepted in the array keys.
2071  *
2072  * Returns the matching MIME type (or wildcard) if a match, otherwise
2073  * NULL if no match.
2074  *
2075  * @param $type String
2076  * @param $avail Array
2077  * @return string
2078  * @private
2079  */
2080 function mimeTypeMatch( $type, $avail ) {
2081         if( array_key_exists( $type, $avail ) ) {
2082                 return $type;
2083         } else {
2084                 $parts = explode( '/', $type );
2085                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2086                         return $parts[0] . '/*';
2087                 } elseif( array_key_exists( '*/*', $avail ) ) {
2088                         return '*/*';
2089                 } else {
2090                         return null;
2091                 }
2092         }
2093 }
2094
2095 /**
2096  * Returns the 'best' match between a client's requested internet media types
2097  * and the server's list of available types. Each list should be an associative
2098  * array of type to preference (preference is a float between 0.0 and 1.0).
2099  * Wildcards in the types are acceptable.
2100  *
2101  * @param $cprefs Array: client's acceptable type list
2102  * @param $sprefs Array: server's offered types
2103  * @return string
2104  *
2105  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2106  * XXX: generalize to negotiate other stuff
2107  */
2108 function wfNegotiateType( $cprefs, $sprefs ) {
2109         $combine = array();
2110
2111         foreach( array_keys($sprefs) as $type ) {
2112                 $parts = explode( '/', $type );
2113                 if( $parts[1] != '*' ) {
2114                         $ckey = mimeTypeMatch( $type, $cprefs );
2115                         if( $ckey ) {
2116                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2117                         }
2118                 }
2119         }
2120
2121         foreach( array_keys( $cprefs ) as $type ) {
2122                 $parts = explode( '/', $type );
2123                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2124                         $skey = mimeTypeMatch( $type, $sprefs );
2125                         if( $skey ) {
2126                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2127                         }
2128                 }
2129         }
2130
2131         $bestq = 0;
2132         $besttype = null;
2133
2134         foreach( array_keys( $combine ) as $type ) {
2135                 if( $combine[$type] > $bestq ) {
2136                         $besttype = $type;
2137                         $bestq = $combine[$type];
2138                 }
2139         }
2140
2141         return $besttype;
2142 }
2143
2144 /**
2145  * Reference-counted warning suppression
2146  *
2147  * @param $end Bool
2148  */
2149 function wfSuppressWarnings( $end = false ) {
2150         static $suppressCount = 0;
2151         static $originalLevel = false;
2152
2153         if ( $end ) {
2154                 if ( $suppressCount ) {
2155                         --$suppressCount;
2156                         if ( !$suppressCount ) {
2157                                 error_reporting( $originalLevel );
2158                         }
2159                 }
2160         } else {
2161                 if ( !$suppressCount ) {
2162                         // E_DEPRECATED is undefined in PHP 5.2
2163                         if( !defined( 'E_DEPRECATED' ) ){
2164                                 define( 'E_DEPRECATED', 8192 );
2165                         }
2166                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2167                 }
2168                 ++$suppressCount;
2169         }
2170 }
2171
2172 /**
2173  * Restore error level to previous value
2174  */
2175 function wfRestoreWarnings() {
2176         wfSuppressWarnings( true );
2177 }
2178
2179 # Autodetect, convert and provide timestamps of various types
2180
2181 /**
2182  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2183  */
2184 define( 'TS_UNIX', 0 );
2185
2186 /**
2187  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2188  */
2189 define( 'TS_MW', 1 );
2190
2191 /**
2192  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2193  */
2194 define( 'TS_DB', 2 );
2195
2196 /**
2197  * RFC 2822 format, for E-mail and HTTP headers
2198  */
2199 define( 'TS_RFC2822', 3 );
2200
2201 /**
2202  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2203  *
2204  * This is used by Special:Export
2205  */
2206 define( 'TS_ISO_8601', 4 );
2207
2208 /**
2209  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2210  *
2211  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2212  *       DateTime tag and page 36 for the DateTimeOriginal and
2213  *       DateTimeDigitized tags.
2214  */
2215 define( 'TS_EXIF', 5 );
2216
2217 /**
2218  * Oracle format time.
2219  */
2220 define( 'TS_ORACLE', 6 );
2221
2222 /**
2223  * Postgres format time.
2224  */
2225 define( 'TS_POSTGRES', 7 );
2226
2227 /**
2228  * DB2 format time
2229  */
2230 define( 'TS_DB2', 8 );
2231
2232 /**
2233  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2234  */
2235 define( 'TS_ISO_8601_BASIC', 9 );
2236
2237 /**
2238  * Get a timestamp string in one of various formats
2239  *
2240  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2241  *                    function will autodetect which format is supplied and act
2242  *                    accordingly.
2243  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2244  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2245  */
2246 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2247         $uts = 0;
2248         $da = array();
2249         $strtime = '';
2250
2251         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2252                 $uts = time();
2253                 $strtime = "@$uts";
2254         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2255                 # TS_DB
2256         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2257                 # TS_EXIF
2258         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2259                 # TS_MW
2260         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2261                 # TS_UNIX
2262                 $uts = $ts;
2263                 $strtime = "@$ts"; // Undocumented?
2264         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2265                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2266                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2267                                 str_replace( '+00:00', 'UTC', $ts ) );
2268         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2269                 # TS_ISO_8601
2270         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2271                 #TS_ISO_8601_BASIC
2272         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2273                 # TS_POSTGRES
2274         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2275                 # TS_POSTGRES
2276         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2277                 # TS_DB2
2278         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2279                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2280                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2281                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2282                 # The regex is a superset of rfc2822 for readability
2283                 $strtime = strtok( $ts, ';' );
2284         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2285                 # TS_RFC850
2286                 $strtime = $ts;
2287         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2288                 # asctime
2289                 $strtime = $ts;
2290         } else {
2291                 # Bogus value...
2292                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2293
2294                 return false;
2295         }
2296
2297         static $formats = array(
2298                 TS_UNIX => 'U',
2299                 TS_MW => 'YmdHis',
2300                 TS_DB => 'Y-m-d H:i:s',
2301                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2302                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2303                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2304                 TS_RFC2822 => 'D, d M Y H:i:s',
2305                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2306                 TS_POSTGRES => 'Y-m-d H:i:s',
2307                 TS_DB2 => 'Y-m-d H:i:s',
2308         );
2309
2310         if ( !isset( $formats[$outputtype] ) ) {
2311                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2312         }
2313
2314         if ( function_exists( "date_create" ) ) {
2315                 if ( count( $da ) ) {
2316                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2317                                 (int)$da[1], (int)$da[2], (int)$da[3],
2318                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2319
2320                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2321                 } elseif ( $strtime ) {
2322                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2323                 } else {
2324                         return false;
2325                 }
2326
2327                 if ( !$d ) {
2328                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2329                         return false;
2330                 }
2331
2332                 $output = $d->format( $formats[$outputtype] );
2333         } else {
2334                 if ( count( $da ) ) {
2335                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2336                         // We may want to handle that explicitly at some point
2337                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2338                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2339                 } elseif ( $strtime ) {
2340                         $uts = strtotime( $strtime );
2341                 }
2342
2343                 if ( $uts === false ) {
2344                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2345                         return false;
2346                 }
2347
2348                 if ( TS_UNIX == $outputtype ) {
2349                         return $uts;
2350                 }
2351                 $output = gmdate( $formats[$outputtype], $uts );
2352         }
2353
2354         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2355                 $output .= ' GMT';
2356         }
2357
2358         return $output;
2359 }
2360
2361 /**
2362  * Return a formatted timestamp, or null if input is null.
2363  * For dealing with nullable timestamp columns in the database.
2364  *
2365  * @param $outputtype Integer
2366  * @param $ts String
2367  * @return String
2368  */
2369 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2370         if( is_null( $ts ) ) {
2371                 return null;
2372         } else {
2373                 return wfTimestamp( $outputtype, $ts );
2374         }
2375 }
2376
2377 /**
2378  * Convenience function; returns MediaWiki timestamp for the present time.
2379  *
2380  * @return string
2381  */
2382 function wfTimestampNow() {
2383         # return NOW
2384         return wfTimestamp( TS_MW, time() );
2385 }
2386
2387 /**
2388  * Check if the operating system is Windows
2389  *
2390  * @return Bool: true if it's Windows, False otherwise.
2391  */
2392 function wfIsWindows() {
2393         static $isWindows = null;
2394         if ( $isWindows === null ) {
2395                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2396         }
2397         return $isWindows;
2398 }
2399
2400 /**
2401  * Check if we are running under HipHop
2402  *
2403  * @return Bool
2404  */
2405 function wfIsHipHop() {
2406         return function_exists( 'hphp_thread_set_warmup_enabled' );
2407 }
2408
2409 /**
2410  * Swap two variables
2411  *
2412  * @param $x Mixed
2413  * @param $y Mixed
2414  */
2415 function swap( &$x, &$y ) {
2416         $z = $x;
2417         $x = $y;
2418         $y = $z;
2419 }
2420
2421 /**
2422  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2423  * TEMP environment variables are then checked in sequence, and if none are set
2424  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2425  * or C:\Windows\Temp for Windows and hope for the best.
2426  * It is common to call it with tempnam().
2427  *
2428  * NOTE: When possible, use instead the tmpfile() function to create
2429  * temporary files to avoid race conditions on file creation, etc.
2430  *
2431  * @return String
2432  */
2433 function wfTempDir() {
2434         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2435                 $tmp = getenv( $var );
2436                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2437                         return $tmp;
2438                 }
2439         }
2440         if( function_exists( 'sys_get_temp_dir' ) ) {
2441                 return sys_get_temp_dir();
2442         }
2443         # Usual defaults
2444         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2445 }
2446
2447 /**
2448  * Make directory, and make all parent directories if they don't exist
2449  *
2450  * @param $dir String: full path to directory to create
2451  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2452  * @param $caller String: optional caller param for debugging.
2453  * @return bool
2454  */
2455 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2456         global $wgDirectoryMode;
2457
2458         if ( !is_null( $caller ) ) {
2459                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2460         }
2461
2462         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2463                 return true;
2464         }
2465
2466         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2467
2468         if ( is_null( $mode ) ) {
2469                 $mode = $wgDirectoryMode;
2470         }
2471
2472         // Turn off the normal warning, we're doing our own below
2473         wfSuppressWarnings();
2474         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2475         wfRestoreWarnings();
2476
2477         if( !$ok ) {
2478                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2479                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2480         }
2481         return $ok;
2482 }
2483
2484 /**
2485  * Increment a statistics counter
2486  *
2487  * @param $key String
2488  * @param $count Int
2489  */
2490 function wfIncrStats( $key, $count = 1 ) {
2491         global $wgStatsMethod;
2492
2493         $count = intval( $count );
2494
2495         if( $wgStatsMethod == 'udp' ) {
2496                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2497                 static $socket;
2498
2499                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2500
2501                 if ( !$socket ) {
2502                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2503                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2504                         socket_sendto(
2505                                 $socket,
2506                                 $statline,
2507                                 strlen( $statline ),
2508                                 0,
2509                                 $wgUDPProfilerHost,
2510                                 $wgUDPProfilerPort
2511                         );
2512                 }
2513                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2514                 wfSuppressWarnings();
2515                 socket_sendto(
2516                         $socket,
2517                         $statline,
2518                         strlen( $statline ),
2519                         0,
2520                         $wgUDPProfilerHost,
2521                         $wgUDPProfilerPort
2522                 );
2523                 wfRestoreWarnings();
2524         } elseif( $wgStatsMethod == 'cache' ) {
2525                 global $wgMemc;
2526                 $key = wfMemcKey( 'stats', $key );
2527                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2528                         $wgMemc->add( $key, $count );
2529                 }
2530         } else {
2531                 // Disabled
2532         }
2533 }
2534
2535 /**
2536  * @param $nr Mixed: the number to format
2537  * @param $acc Integer: the number of digits after the decimal point, default 2
2538  * @param $round Boolean: whether or not to round the value, default true
2539  * @return float
2540  */
2541 function wfPercent( $nr, $acc = 2, $round = true ) {
2542         $ret = sprintf( "%.${acc}f", $nr );
2543         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2544 }
2545
2546 /**
2547  * Find out whether or not a mixed variable exists in a string
2548  *
2549  * @param $needle String
2550  * @param $str String
2551  * @param $insensitive Boolean
2552  * @return Boolean
2553  */
2554 function in_string( $needle, $str, $insensitive = false ) {
2555         $func = 'strpos';
2556         if( $insensitive ) $func = 'stripos';
2557
2558         return $func( $str, $needle ) !== false;
2559 }
2560
2561 /**
2562  * Make a list item, used by various special pages
2563  *
2564  * @param $page String Page link
2565  * @param $details String Text between brackets
2566  * @param $oppositedm Boolean   Add the direction mark opposite to your
2567  *                                                              language, to display text properly
2568  * @return String
2569  */
2570 function wfSpecialList( $page, $details, $oppositedm = true ) {
2571         global $wgLang;
2572         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2573                 $wgLang->getDirMark();
2574         $details = $details ? $dirmark . " ($details)" : '';
2575         return $page . $details;
2576 }
2577
2578 /**
2579  * Safety wrapper around ini_get() for boolean settings.
2580  * The values returned from ini_get() are pre-normalized for settings
2581  * set via php.ini or php_flag/php_admin_flag... but *not*
2582  * for those set via php_value/php_admin_value.
2583  *
2584  * It's fairly common for people to use php_value instead of php_flag,
2585  * which can leave you with an 'off' setting giving a false positive
2586  * for code that just takes the ini_get() return value as a boolean.
2587  *
2588  * To make things extra interesting, setting via php_value accepts
2589  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2590  * Unrecognized values go false... again opposite PHP's own coercion
2591  * from string to bool.
2592  *
2593  * Luckily, 'properly' set settings will always come back as '0' or '1',
2594  * so we only have to worry about them and the 'improper' settings.
2595  *
2596  * I frickin' hate PHP... :P
2597  *
2598  * @param $setting String
2599  * @return Bool
2600  */
2601 function wfIniGetBool( $setting ) {
2602         $val = ini_get( $setting );
2603         // 'on' and 'true' can't have whitespace around them, but '1' can.
2604         return strtolower( $val ) == 'on'
2605                 || strtolower( $val ) == 'true'
2606                 || strtolower( $val ) == 'yes'
2607                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2608 }
2609
2610 /**
2611  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2612  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2613  *
2614  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2615  *                          should be omitted
2616  * @param $fileName String Name of the library, if not $extension.suffix
2617  * @return Bool - Whether or not the extension is loaded
2618  */
2619 function wfDl( $extension, $fileName = null ) {
2620         if( extension_loaded( $extension ) ) {
2621                 return true;
2622         }
2623
2624         $canDl = false;
2625         $sapi = php_sapi_name();
2626         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2627                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2628         {
2629                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2630                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2631         }
2632
2633         if( $canDl ) {
2634                 $fileName = $fileName ? $fileName : $extension;
2635                 if( wfIsWindows() ) {
2636                         $fileName = 'php_' . $fileName;
2637                 }
2638                 wfSuppressWarnings();
2639                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2640                 wfRestoreWarnings();
2641         }
2642         return extension_loaded( $extension );
2643 }
2644
2645 /**
2646  * Execute a shell command, with time and memory limits mirrored from the PHP
2647  * configuration if supported.
2648  * @param $cmd String Command line, properly escaped for shell.
2649  * @param &$retval optional, will receive the program's exit code.
2650  *                 (non-zero is usually failure)
2651  * @param $environ Array optional environment variables which should be
2652  *                 added to the executed command environment.
2653  * @return collected stdout as a string (trailing newlines stripped)
2654  */
2655 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2656         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2657
2658         static $disabled;
2659         if ( is_null( $disabled ) ) {
2660                 $disabled = false;
2661                 if( wfIniGetBool( 'safe_mode' ) ) {
2662                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2663                         $disabled = 'safemode';
2664                 } else {
2665                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2666                         $functions = array_map( 'trim', $functions );
2667                         $functions = array_map( 'strtolower', $functions );
2668                         if ( in_array( 'passthru', $functions ) ) {
2669                                 wfDebug( "passthru is in disabled_functions\n" );
2670                                 $disabled = 'passthru';
2671                         }
2672                 }
2673         }
2674         if ( $disabled ) {
2675                 $retval = 1;
2676                 return $disabled == 'safemode' ?
2677                         'Unable to run external programs in safe mode.' :
2678                         'Unable to run external programs, passthru() is disabled.';
2679         }
2680
2681         wfInitShellLocale();
2682
2683         $envcmd = '';
2684         foreach( $environ as $k => $v ) {
2685                 if ( wfIsWindows() ) {
2686                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2687                          * appear in the environment variable, so we must use carat escaping as documented in
2688                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2689                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2690                          * are listed there but doesn't appear to need it.
2691                          */
2692                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2693                 } else {
2694                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2695                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2696                          */
2697                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2698                 }
2699         }
2700         $cmd = $envcmd . $cmd;
2701
2702         if ( wfIsWindows() ) {
2703                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2704                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2705                 {
2706                         # Hack to work around PHP's flawed invocation of cmd.exe
2707                         # http://news.php.net/php.internals/21796
2708                         # Windows 9x doesn't accept any kind of quotes
2709                         $cmd = '"' . $cmd . '"';
2710                 }
2711         } elseif ( php_uname( 's' ) == 'Linux' ) {
2712                 $time = intval( $wgMaxShellTime );
2713                 $mem = intval( $wgMaxShellMemory );
2714                 $filesize = intval( $wgMaxShellFileSize );
2715
2716                 if ( $time > 0 && $mem > 0 ) {
2717                         $script = "$IP/bin/ulimit4.sh";
2718                         if ( is_executable( $script ) ) {
2719                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2720                         }
2721                 }
2722         }
2723         wfDebug( "wfShellExec: $cmd\n" );
2724
2725         $retval = 1; // error by default?
2726         ob_start();
2727         passthru( $cmd, $retval );
2728         $output = ob_get_contents();
2729         ob_end_clean();
2730
2731         if ( $retval == 127 ) {
2732                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2733         }
2734         return $output;
2735 }
2736
2737 /**
2738  * Workaround for http://bugs.php.net/bug.php?id=45132
2739  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2740  */
2741 function wfInitShellLocale() {
2742         static $done = false;
2743         if ( $done ) {
2744                 return;
2745         }
2746         $done = true;
2747         global $wgShellLocale;
2748         if ( !wfIniGetBool( 'safe_mode' ) ) {
2749                 putenv( "LC_CTYPE=$wgShellLocale" );
2750                 setlocale( LC_CTYPE, $wgShellLocale );
2751         }
2752 }
2753
2754 /**
2755  * This function works like "use VERSION" in Perl, the program will die with a
2756  * backtrace if the current version of PHP is less than the version provided
2757  *
2758  * This is useful for extensions which due to their nature are not kept in sync
2759  * with releases, and might depend on other versions of PHP than the main code
2760  *
2761  * Note: PHP might die due to parsing errors in some cases before it ever
2762  *       manages to call this function, such is life
2763  *
2764  * @see perldoc -f use
2765  *
2766  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2767  *                 a float
2768  */
2769 function wfUsePHP( $req_ver ) {
2770         $php_ver = PHP_VERSION;
2771
2772         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2773                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2774         }
2775 }
2776
2777 /**
2778  * This function works like "use VERSION" in Perl except it checks the version
2779  * of MediaWiki, the program will die with a backtrace if the current version
2780  * of MediaWiki is less than the version provided.
2781  *
2782  * This is useful for extensions which due to their nature are not kept in sync
2783  * with releases
2784  *
2785  * @see perldoc -f use
2786  *
2787  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2788  *                 a float
2789  */
2790 function wfUseMW( $req_ver ) {
2791         global $wgVersion;
2792
2793         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2794                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2795         }
2796 }
2797
2798 /**
2799  * Return the final portion of a pathname.
2800  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2801  * http://bugs.php.net/bug.php?id=33898
2802  *
2803  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2804  * We'll consider it so always, as we don't want \s in our Unix paths either.
2805  *
2806  * @param $path String
2807  * @param $suffix String: to remove if present
2808  * @return String
2809  */
2810 function wfBaseName( $path, $suffix = '' ) {
2811         $encSuffix = ( $suffix == '' )
2812                 ? ''
2813                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2814         $matches = array();
2815         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2816                 return $matches[1];
2817         } else {
2818                 return '';
2819         }
2820 }
2821
2822 /**
2823  * Generate a relative path name to the given file.
2824  * May explode on non-matching case-insensitive paths,
2825  * funky symlinks, etc.
2826  *
2827  * @param $path String: absolute destination path including target filename
2828  * @param $from String: Absolute source path, directory only
2829  * @return String
2830  */
2831 function wfRelativePath( $path, $from ) {
2832         // Normalize mixed input on Windows...
2833         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2834         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2835
2836         // Trim trailing slashes -- fix for drive root
2837         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2838         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2839
2840         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2841         $against = explode( DIRECTORY_SEPARATOR, $from );
2842
2843         if( $pieces[0] !== $against[0] ) {
2844                 // Non-matching Windows drive letters?
2845                 // Return a full path.
2846                 return $path;
2847         }
2848
2849         // Trim off common prefix
2850         while( count( $pieces ) && count( $against )
2851                 && $pieces[0] == $against[0] ) {
2852                 array_shift( $pieces );
2853                 array_shift( $against );
2854         }
2855
2856         // relative dots to bump us to the parent
2857         while( count( $against ) ) {
2858                 array_unshift( $pieces, '..' );
2859                 array_shift( $against );
2860         }
2861
2862         array_push( $pieces, wfBaseName( $path ) );
2863
2864         return implode( DIRECTORY_SEPARATOR, $pieces );
2865 }
2866
2867 /**
2868  * Do any deferred updates and clear the list
2869  *
2870  * @param $commit String: set to 'commit' to commit after every update to
2871  *                prevent lock contention
2872  */
2873 function wfDoUpdates( $commit = '' ) {
2874         global $wgDeferredUpdateList;
2875
2876         wfProfileIn( __METHOD__ );
2877
2878         // No need to get master connections in case of empty updates array
2879         if ( !count( $wgDeferredUpdateList ) ) {
2880                 wfProfileOut( __METHOD__ );
2881                 return;
2882         }
2883
2884         $doCommit = $commit == 'commit';
2885         if ( $doCommit ) {
2886                 $dbw = wfGetDB( DB_MASTER );
2887         }
2888
2889         foreach ( $wgDeferredUpdateList as $update ) {
2890                 $update->doUpdate();
2891
2892                 if ( $doCommit && $dbw->trxLevel() ) {
2893                         $dbw->commit();
2894                 }
2895         }
2896
2897         $wgDeferredUpdateList = array();
2898         wfProfileOut( __METHOD__ );
2899 }
2900
2901 /**
2902  * Convert an arbitrarily-long digit string from one numeric base
2903  * to another, optionally zero-padding to a minimum column width.
2904  *
2905  * Supports base 2 through 36; digit values 10-36 are represented
2906  * as lowercase letters a-z. Input is case-insensitive.
2907  *
2908  * @param $input String: of digits
2909  * @param $sourceBase Integer: 2-36
2910  * @param $destBase Integer: 2-36
2911  * @param $pad Integer: 1 or greater
2912  * @param $lowercase Boolean
2913  * @return String or false on invalid input
2914  */
2915 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2916         $input = strval( $input );
2917         if( $sourceBase < 2 ||
2918                 $sourceBase > 36 ||
2919                 $destBase < 2 ||
2920                 $destBase > 36 ||
2921                 $pad < 1 ||
2922                 $sourceBase != intval( $sourceBase ) ||
2923                 $destBase != intval( $destBase ) ||
2924                 $pad != intval( $pad ) ||
2925                 !is_string( $input ) ||
2926                 $input == '' ) {
2927                 return false;
2928         }
2929         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2930         $inDigits = array();
2931         $outChars = '';
2932
2933         // Decode and validate input string
2934         $input = strtolower( $input );
2935         for( $i = 0; $i < strlen( $input ); $i++ ) {
2936                 $n = strpos( $digitChars, $input[$i] );
2937                 if( $n === false || $n > $sourceBase ) {
2938                         return false;
2939                 }
2940                 $inDigits[] = $n;
2941         }
2942
2943         // Iterate over the input, modulo-ing out an output digit
2944         // at a time until input is gone.
2945         while( count( $inDigits ) ) {
2946                 $work = 0;
2947                 $workDigits = array();
2948
2949                 // Long division...
2950                 foreach( $inDigits as $digit ) {
2951                         $work *= $sourceBase;
2952                         $work += $digit;
2953
2954                         if( $work < $destBase ) {
2955                                 // Gonna need to pull another digit.
2956                                 if( count( $workDigits ) ) {
2957                                         // Avoid zero-padding; this lets us find
2958                                         // the end of the input very easily when
2959                                         // length drops to zero.
2960                                         $workDigits[] = 0;
2961                                 }
2962                         } else {
2963                                 // Finally! Actual division!
2964                                 $workDigits[] = intval( $work / $destBase );
2965
2966                                 // Isn't it annoying that most programming languages
2967                                 // don't have a single divide-and-remainder operator,
2968                                 // even though the CPU implements it that way?
2969                                 $work = $work % $destBase;
2970                         }
2971                 }
2972
2973                 // All that division leaves us with a remainder,
2974                 // which is conveniently our next output digit.
2975                 $outChars .= $digitChars[$work];
2976
2977                 // And we continue!
2978                 $inDigits = $workDigits;
2979         }
2980
2981         while( strlen( $outChars ) < $pad ) {
2982                 $outChars .= '0';
2983         }
2984
2985         return strrev( $outChars );
2986 }
2987
2988 /**
2989  * Create an object with a given name and an array of construct parameters
2990  *
2991  * @param $name String
2992  * @param $p Array: parameters
2993  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
2994  */
2995 function wfCreateObject( $name, $p ) {
2996         wfDeprecated( __FUNCTION__ );
2997         return MWFunction::newObj( $name, $p );
2998 }
2999
3000 function wfHttpOnlySafe() {
3001         global $wgHttpOnlyBlacklist;
3002
3003         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3004                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3005                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3006                                 return false;
3007                         }
3008                 }
3009         }
3010
3011         return true;
3012 }
3013
3014 /**
3015  * Initialise php session
3016  *
3017  * @param $sessionId Bool
3018  */
3019 function wfSetupSession( $sessionId = false ) {
3020         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3021                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3022         if( $wgSessionsInMemcached ) {
3023                 if ( !defined( 'MW_COMPILED' ) ) {
3024                         global $IP;
3025                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3026                 }
3027                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3028                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3029
3030                 // It's necessary to register a shutdown function to call session_write_close(),
3031                 // because by the time the request shutdown function for the session module is
3032                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3033                 // this way are called before object destruction.
3034                 register_shutdown_function( 'memsess_write_close' );
3035         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3036                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3037                 # hasn't already been set to the desired value (that causes errors)
3038                 ini_set( 'session.save_handler', $wgSessionHandler );
3039         }
3040         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3041         wfDebugLog( 'cookie',
3042                 'session_set_cookie_params: "' . implode( '", "',
3043                         array(
3044                                 0,
3045                                 $wgCookiePath,
3046                                 $wgCookieDomain,
3047                                 $wgCookieSecure,
3048                                 $httpOnlySafe ) ) . '"' );
3049         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3050         session_cache_limiter( 'private, must-revalidate' );
3051         if ( $sessionId ) {
3052                 session_id( $sessionId );
3053         }
3054         wfSuppressWarnings();
3055         session_start();
3056         wfRestoreWarnings();
3057 }
3058
3059 /**
3060  * Get an object from the precompiled serialized directory
3061  *
3062  * @param $name String
3063  * @return Mixed: the variable on success, false on failure
3064  */
3065 function wfGetPrecompiledData( $name ) {
3066         global $IP;
3067
3068         $file = "$IP/serialized/$name";
3069         if ( file_exists( $file ) ) {
3070                 $blob = file_get_contents( $file );
3071                 if ( $blob ) {
3072                         return unserialize( $blob );
3073                 }
3074         }
3075         return false;
3076 }
3077
3078 /**
3079  * Get a cache key
3080  *
3081  * @param varargs
3082  * @return String
3083  */
3084 function wfMemcKey( /*... */ ) {
3085         $args = func_get_args();
3086         $key = wfWikiID() . ':' . implode( ':', $args );
3087         $key = str_replace( ' ', '_', $key );
3088         return $key;
3089 }
3090
3091 /**
3092  * Get a cache key for a foreign DB
3093  *
3094  * @param $db String
3095  * @param $prefix String
3096  * @param varargs String
3097  * @return String
3098  */
3099 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3100         $args = array_slice( func_get_args(), 2 );
3101         if ( $prefix ) {
3102                 $key = "$db-$prefix:" . implode( ':', $args );
3103         } else {
3104                 $key = $db . ':' . implode( ':', $args );
3105         }
3106         return $key;
3107 }
3108
3109 /**
3110  * Get an ASCII string identifying this wiki
3111  * This is used as a prefix in memcached keys
3112  *
3113  * @return String
3114  */
3115 function wfWikiID() {
3116         global $wgDBprefix, $wgDBname;
3117         if ( $wgDBprefix ) {
3118                 return "$wgDBname-$wgDBprefix";
3119         } else {
3120                 return $wgDBname;
3121         }
3122 }
3123
3124 /**
3125  * Split a wiki ID into DB name and table prefix
3126  *
3127  * @param $wiki String
3128  * @param $bits String
3129  */
3130 function wfSplitWikiID( $wiki ) {
3131         $bits = explode( '-', $wiki, 2 );
3132         if ( count( $bits ) < 2 ) {
3133                 $bits[] = '';
3134         }
3135         return $bits;
3136 }
3137
3138 /**
3139  * Get a Database object.
3140  *
3141  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3142  *            master (for write queries), DB_SLAVE for potentially lagged read
3143  *            queries, or an integer >= 0 for a particular server.
3144  *
3145  * @param $groups Mixed: query groups. An array of group names that this query
3146  *                belongs to. May contain a single string if the query is only
3147  *                in one group.
3148  *
3149  * @param $wiki String: the wiki ID, or false for the current wiki
3150  *
3151  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3152  * will always return the same object, unless the underlying connection or load
3153  * balancer is manually destroyed.
3154  *
3155  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3156  * updater to ensure that a proper database is being updated.
3157  *
3158  * @return DatabaseBase
3159  */
3160 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3161         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3162 }
3163
3164 /**
3165  * Get a load balancer object.
3166  *
3167  * @param $wiki String: wiki ID, or false for the current wiki
3168  * @return LoadBalancer
3169  */
3170 function wfGetLB( $wiki = false ) {
3171         return wfGetLBFactory()->getMainLB( $wiki );
3172 }
3173
3174 /**
3175  * Get the load balancer factory object
3176  *
3177  * @return LBFactory
3178  */
3179 function &wfGetLBFactory() {
3180         return LBFactory::singleton();
3181 }
3182
3183 /**
3184  * Find a file.
3185  * Shortcut for RepoGroup::singleton()->findFile()
3186  *
3187  * @param $title String or Title object
3188  * @param $options Associative array of options:
3189  *     time:           requested time for an archived image, or false for the
3190  *                     current version. An image object will be returned which was
3191  *                     created at the specified time.
3192  *
3193  *     ignoreRedirect: If true, do not follow file redirects
3194  *
3195  *     private:        If true, return restricted (deleted) files if the current
3196  *                     user is allowed to view them. Otherwise, such files will not
3197  *                     be found.
3198  *
3199  *     bypassCache:    If true, do not use the process-local cache of File objects
3200  *
3201  * @return File, or false if the file does not exist
3202  */
3203 function wfFindFile( $title, $options = array() ) {
3204         return RepoGroup::singleton()->findFile( $title, $options );
3205 }
3206
3207 /**
3208  * Get an object referring to a locally registered file.
3209  * Returns a valid placeholder object if the file does not exist.
3210  *
3211  * @param $title Title or String
3212  * @return File, or null if passed an invalid Title
3213  */
3214 function wfLocalFile( $title ) {
3215         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3216 }
3217
3218 /**
3219  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3220  * @deprecated since 1.19
3221  */
3222 function wfStreamFile( $fname, $headers = array() ) {
3223         StreamFile::stream( $fname, $headers );
3224 }
3225
3226 /**
3227  * Should low-performance queries be disabled?
3228  *
3229  * @return Boolean
3230  * @codeCoverageIgnore
3231  */
3232 function wfQueriesMustScale() {
3233         global $wgMiserMode;
3234         return $wgMiserMode
3235                 || ( SiteStats::pages() > 100000
3236                 && SiteStats::edits() > 1000000
3237                 && SiteStats::users() > 10000 );
3238 }
3239
3240 /**
3241  * Get the path to a specified script file, respecting file
3242  * extensions; this is a wrapper around $wgScriptExtension etc.
3243  *
3244  * @param $script String: script filename, sans extension
3245  * @return String
3246  */
3247 function wfScript( $script = 'index' ) {
3248         global $wgScriptPath, $wgScriptExtension;
3249         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3250 }
3251
3252 /**
3253  * Get the script URL.
3254  *
3255  * @return script URL
3256  */
3257 function wfGetScriptUrl() {
3258         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3259                 #
3260                 # as it was called, minus the query string.
3261                 #
3262                 # Some sites use Apache rewrite rules to handle subdomains,
3263                 # and have PHP set up in a weird way that causes PHP_SELF
3264                 # to contain the rewritten URL instead of the one that the
3265                 # outside world sees.
3266                 #
3267                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3268                 # provides containing the "before" URL.
3269                 return $_SERVER['SCRIPT_NAME'];
3270         } else {
3271                 return $_SERVER['URL'];
3272         }
3273 }
3274
3275 /**
3276  * Convenience function converts boolean values into "true"
3277  * or "false" (string) values
3278  *
3279  * @param $value Boolean
3280  * @return String
3281  */
3282 function wfBoolToStr( $value ) {
3283         return $value ? 'true' : 'false';
3284 }
3285
3286 /**
3287  * Load an extension messages file
3288  *
3289  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3290  * @codeCoverageIgnore
3291  */
3292 function wfLoadExtensionMessages() {
3293         wfDeprecated( __FUNCTION__ );
3294 }
3295
3296 /**
3297  * Get a platform-independent path to the null file, e.g. /dev/null
3298  *
3299  * @return string
3300  */
3301 function wfGetNull() {
3302         return wfIsWindows()
3303                 ? 'NUL'
3304                 : '/dev/null';
3305 }
3306
3307 /**
3308  * Throws a warning that $function is deprecated
3309  *
3310  * @param $function String
3311  * @return null
3312  */
3313 function wfDeprecated( $function ) {
3314         static $functionsWarned = array();
3315         if ( !isset( $functionsWarned[$function] ) ) {
3316                 $functionsWarned[$function] = true;
3317                 wfWarn( "Use of $function is deprecated.", 2 );
3318         }
3319 }
3320
3321 /**
3322  * Send a warning either to the debug log or in a PHP error depending on
3323  * $wgDevelopmentWarnings
3324  *
3325  * @param $msg String: message to send
3326  * @param $callerOffset Integer: number of items to go back in the backtrace to
3327  *        find the correct caller (1 = function calling wfWarn, ...)
3328  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3329  *        is true
3330  */
3331 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3332         global $wgDevelopmentWarnings;
3333
3334         $callers = wfDebugBacktrace();
3335         if ( isset( $callers[$callerOffset + 1] ) ) {
3336                 $callerfunc = $callers[$callerOffset + 1];
3337                 $callerfile = $callers[$callerOffset];
3338                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3339                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3340                 } else {
3341                         $file = '(internal function)';
3342                 }
3343                 $func = '';
3344                 if ( isset( $callerfunc['class'] ) ) {
3345                         $func .= $callerfunc['class'] . '::';
3346                 }
3347                 if ( isset( $callerfunc['function'] ) ) {
3348                         $func .= $callerfunc['function'];
3349                 }
3350                 $msg .= " [Called from $func in $file]";
3351         }
3352
3353         if ( $wgDevelopmentWarnings ) {
3354                 trigger_error( $msg, $level );
3355         } else {
3356                 wfDebug( "$msg\n" );
3357         }
3358 }
3359
3360 /**
3361  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3362  * and waiting for it to go down, this waits for the slaves to catch up to the
3363  * master position. Use this when updating very large numbers of rows, as
3364  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3365  * a no-op if there are no slaves.
3366  *
3367  * @param $maxLag Integer (deprecated)
3368  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3369  * @return null
3370  */
3371 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3372         $lb = wfGetLB( $wiki );
3373         // bug 27975 - Don't try to wait for slaves if there are none
3374         // Prevents permission error when getting master position
3375         if ( $lb->getServerCount() > 1 ) {
3376                 $dbw = $lb->getConnection( DB_MASTER );
3377                 $pos = $dbw->getMasterPos();
3378                 $lb->waitForAll( $pos );
3379         }
3380 }
3381
3382 /**
3383  * Used to be used for outputting text in the installer/updater
3384  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3385  */
3386 function wfOut( $s ) {
3387         wfDeprecated( __METHOD__ );
3388         global $wgCommandLineMode;
3389         if ( $wgCommandLineMode ) {
3390                 echo $s;
3391         } else {
3392                 echo htmlspecialchars( $s );
3393         }
3394         flush();
3395 }
3396
3397 /**
3398  * Count down from $n to zero on the terminal, with a one-second pause
3399  * between showing each number. For use in command-line scripts.
3400  * @codeCoverageIgnore
3401  */
3402 function wfCountDown( $n ) {
3403         for ( $i = $n; $i >= 0; $i-- ) {
3404                 if ( $i != $n ) {
3405                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3406                 }
3407                 echo $i;
3408                 flush();
3409                 if ( $i ) {
3410                         sleep( 1 );
3411                 }
3412         }
3413         echo "\n";
3414 }
3415
3416 /**
3417  * Generate a random 32-character hexadecimal token.
3418  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3419  *              characters before hashing.
3420  * @return string
3421  * @codeCoverageIgnore
3422  */
3423 function wfGenerateToken( $salt = '' ) {
3424         $salt = serialize( $salt );
3425         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3426 }
3427
3428 /**
3429  * Replace all invalid characters with -
3430  *
3431  * @param $name Mixed: filename to process
3432  * @return String
3433  */
3434 function wfStripIllegalFilenameChars( $name ) {
3435         global $wgIllegalFileChars;
3436         $name = wfBaseName( $name );
3437         $name = preg_replace(
3438                 "/[^" . Title::legalChars() . "]" .
3439                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3440                         "/",
3441                 '-',
3442                 $name
3443         );
3444         return $name;
3445 }
3446
3447 /**
3448  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3449  *
3450  * @return Integer value memory was set to.
3451  */
3452 function wfMemoryLimit() {
3453         global $wgMemoryLimit;
3454         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3455         if( $memlimit != -1 ) {
3456                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3457                 if( $conflimit == -1 ) {
3458                         wfDebug( "Removing PHP's memory limit\n" );
3459                         wfSuppressWarnings();
3460                         ini_set( 'memory_limit', $conflimit );
3461                         wfRestoreWarnings();
3462                         return $conflimit;
3463                 } elseif ( $conflimit > $memlimit ) {
3464                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3465                         wfSuppressWarnings();
3466                         ini_set( 'memory_limit', $conflimit );
3467                         wfRestoreWarnings();
3468                         return $conflimit;
3469                 }
3470         }
3471         return $memlimit;
3472 }
3473
3474 /**
3475  * Converts shorthand byte notation to integer form
3476  *
3477  * @param $string String
3478  * @return Integer
3479  */
3480 function wfShorthandToInteger( $string = '' ) {
3481         $string = trim( $string );
3482         if( $string === '' ) {
3483                 return -1;
3484         }
3485         $last = $string[strlen( $string ) - 1];
3486         $val = intval( $string );
3487         switch( $last ) {
3488                 case 'g':
3489                 case 'G':
3490                         $val *= 1024;
3491                         // break intentionally missing
3492                 case 'm':
3493                 case 'M':
3494                         $val *= 1024;
3495                         // break intentionally missing
3496                 case 'k':
3497                 case 'K':
3498                         $val *= 1024;
3499         }
3500
3501         return $val;
3502 }
3503
3504 /**
3505  * Get the normalised IETF language tag
3506  * See unit test for examples.
3507  *
3508  * @param $code String: The language code.
3509  * @return $langCode String: The language code which complying with BCP 47 standards.
3510  */
3511 function wfBCP47( $code ) {
3512         $codeSegment = explode( '-', $code );
3513         $codeBCP = array();
3514         foreach ( $codeSegment as $segNo => $seg ) {
3515                 if ( count( $codeSegment ) > 0 ) {
3516                         // when previous segment is x, it is a private segment and should be lc
3517                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3518                                 $codeBCP[$segNo] = strtolower( $seg );
3519                         // ISO 3166 country code
3520                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3521                                 $codeBCP[$segNo] = strtoupper( $seg );
3522                         // ISO 15924 script code
3523                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3524                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3525                         // Use lowercase for other cases
3526                         } else {
3527                                 $codeBCP[$segNo] = strtolower( $seg );
3528                         }
3529                 } else {
3530                 // Use lowercase for single segment
3531                         $codeBCP[$segNo] = strtolower( $seg );
3532                 }
3533         }
3534         $langCode = implode( '-', $codeBCP );
3535         return $langCode;
3536 }
3537
3538 /**
3539  * Get a cache object.
3540  *
3541  * @param $inputType integer Cache type, one the the CACHE_* constants.
3542  * @return BagOStuff
3543  */
3544 function wfGetCache( $inputType ) {
3545         return ObjectCache::getInstance( $inputType );
3546 }
3547
3548 /**
3549  * Get the main cache object
3550  *
3551  * @return BagOStuff
3552  */
3553 function wfGetMainCache() {
3554         global $wgMainCacheType;
3555         return ObjectCache::getInstance( $wgMainCacheType );
3556 }
3557
3558 /**
3559  * Get the cache object used by the message cache
3560  *
3561  * @return BagOStuff
3562  */
3563 function wfGetMessageCacheStorage() {
3564         global $wgMessageCacheType;
3565         return ObjectCache::getInstance( $wgMessageCacheType );
3566 }
3567
3568 /**
3569  * Get the cache object used by the parser cache
3570  *
3571  * @return BagOStuff
3572  */
3573 function wfGetParserCacheStorage() {
3574         global $wgParserCacheType;
3575         return ObjectCache::getInstance( $wgParserCacheType );
3576 }
3577
3578 /**
3579  * Call hook functions defined in $wgHooks
3580  *
3581  * @param $event String: event name
3582  * @param $args Array: parameters passed to hook functions
3583  * @return Boolean
3584  */
3585 function wfRunHooks( $event, $args = array() ) {
3586         return Hooks::run( $event, $args );
3587 }