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/includes/ -> unicode.inc (source)

   1  <?php
   2  
   3  /**
   4   * Indicates an error during check for PHP unicode support.
   5   */
   6  define('UNICODE_ERROR', -1);
   7  
   8  /**
   9   * Indicates that standard PHP (emulated) unicode support is being used.
  10   */
  11  define('UNICODE_SINGLEBYTE', 0);
  12  
  13  /**
  14   * Indicates that full unicode support with the PHP mbstring extension is being
  15   * used.
  16   */
  17  define('UNICODE_MULTIBYTE', 1);
  18  
  19  /**
  20   * Wrapper around _unicode_check().
  21   */
  22  function unicode_check() {
  23    list($GLOBALS['multibyte']) = _unicode_check();
  24  }
  25  
  26  /**
  27   * Perform checks about Unicode support in PHP, and set the right settings if
  28   * needed.
  29   *
  30   * Because Drupal needs to be able to handle text in various encodings, we do
  31   * not support mbstring function overloading. HTTP input/output conversion must
  32   * be disabled for similar reasons.
  33   *
  34   * @param $errors
  35   *   Whether to report any fatal errors with form_set_error().
  36   */
  37  function _unicode_check() {
  38    // Ensure translations don't break at install time
  39    $t = get_t();
  40  
  41    // Set the standard C locale to ensure consistent, ASCII-only string handling.
  42    setlocale(LC_CTYPE, 'C');
  43  
  44    // Check for outdated PCRE library
  45    // Note: we check if U+E2 is in the range U+E0 - U+E1. This test returns TRUE on old PCRE versions.
  46    if (preg_match('/[à-á]/u', 'â')) {
  47      return array(UNICODE_ERROR, $t('The PCRE library in your PHP installation is outdated. This will cause problems when handling Unicode text. If you are running PHP 4.3.3 or higher, make sure you are using the PCRE library supplied by PHP. Please refer to the <a href="@url">PHP PCRE documentation</a> for more information.', array('@url' => 'http://www.php.net/pcre')));
  48    }
  49  
  50    // Check for mbstring extension
  51    if (!function_exists('mb_strlen')) {
  52      return array(UNICODE_SINGLEBYTE, $t('Operations on Unicode strings are emulated on a best-effort basis. Install the <a href="@url">PHP mbstring extension</a> for improved Unicode support.', array('@url' => 'http://www.php.net/mbstring')));
  53    }
  54  
  55    // Check mbstring configuration
  56    if (ini_get('mbstring.func_overload') != 0) {
  57      return array(UNICODE_ERROR, $t('Multibyte string function overloading in PHP is active and must be disabled. Check the php.ini <em>mbstring.func_overload</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
  58    }
  59    if (ini_get('mbstring.encoding_translation') != 0) {
  60      return array(UNICODE_ERROR, $t('Multibyte string input conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.encoding_translation</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
  61    }
  62    if (ini_get('mbstring.http_input') != 'pass') {
  63      return array(UNICODE_ERROR, $t('Multibyte string input conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.http_input</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
  64    }
  65    if (ini_get('mbstring.http_output') != 'pass') {
  66      return array(UNICODE_ERROR, $t('Multibyte string output conversion in PHP is active and must be disabled. Check the php.ini <em>mbstring.http_output</em> setting. Please refer to the <a href="@url">PHP mbstring documentation</a> for more information.', array('@url' => 'http://www.php.net/mbstring')));
  67    }
  68  
  69    // Set appropriate configuration
  70    mb_internal_encoding('utf-8');
  71    mb_language('uni');
  72    return array(UNICODE_MULTIBYTE, '');
  73  }
  74  
  75  /**
  76   * Return Unicode library status and errors.
  77   */
  78  function unicode_requirements() {
  79    // Ensure translations don't break at install time
  80    $t = get_t();
  81  
  82    $libraries = array(
  83      UNICODE_SINGLEBYTE => $t('Standard PHP'),
  84      UNICODE_MULTIBYTE => $t('PHP Mbstring Extension'),
  85      UNICODE_ERROR => $t('Error'),
  86    );
  87    $severities = array(
  88      UNICODE_SINGLEBYTE => REQUIREMENT_WARNING,
  89      UNICODE_MULTIBYTE => REQUIREMENT_OK,
  90      UNICODE_ERROR => REQUIREMENT_ERROR,
  91    );
  92    list($library, $description) = _unicode_check();
  93  
  94    $requirements['unicode'] = array(
  95      'title' => $t('Unicode library'),
  96      'value' => $libraries[$library],
  97    );
  98    if ($description) {
  99      $requirements['unicode']['description'] = $description;
 100    }
 101  
 102    $requirements['unicode']['severity'] = $severities[$library];
 103  
 104    return $requirements;
 105  }
 106  
 107  /**
 108   * Prepare a new XML parser.
 109   *
 110   * This is a wrapper around xml_parser_create() which extracts the encoding from
 111   * the XML data first and sets the output encoding to UTF-8. This function should
 112   * be used instead of xml_parser_create(), because PHP 4's XML parser doesn't
 113   * check the input encoding itself. "Starting from PHP 5, the input encoding is
 114   * automatically detected, so that the encoding parameter specifies only the
 115   * output encoding."
 116   *
 117   * This is also where unsupported encodings will be converted. Callers should
 118   * take this into account: $data might have been changed after the call.
 119   *
 120   * @param &$data
 121   *   The XML data which will be parsed later.
 122   * @return
 123   *   An XML parser object.
 124   */
 125  function drupal_xml_parser_create(&$data) {
 126    // Default XML encoding is UTF-8
 127    $encoding = 'utf-8';
 128    $bom = FALSE;
 129  
 130    // Check for UTF-8 byte order mark (PHP5's XML parser doesn't handle it).
 131    if (!strncmp($data, "\xEF\xBB\xBF", 3)) {
 132      $bom = TRUE;
 133      $data = substr($data, 3);
 134    }
 135  
 136    // Check for an encoding declaration in the XML prolog if no BOM was found.
 137    if (!$bom && @ereg('^<\?xml[^>]+encoding="([^"]+)"', $data, $match)) {
 138      $encoding = $match[1];
 139    }
 140  
 141    // Unsupported encodings are converted here into UTF-8.
 142    $php_supported = array('utf-8', 'iso-8859-1', 'us-ascii');
 143    if (!in_array(strtolower($encoding), $php_supported)) {
 144      $out = drupal_convert_to_utf8($data, $encoding);
 145      if ($out !== FALSE) {
 146        $encoding = 'utf-8';
 147        $data = @ereg_replace('^(<\?xml[^>]+encoding)="([^"]+)"', '\\1="utf-8"', $out);
 148      }
 149      else {
 150        watchdog('php', 'Could not convert XML encoding %s to UTF-8.', array('%s' => $encoding), WATCHDOG_WARNING);
 151        return 0;
 152      }
 153    }
 154  
 155    $xml_parser = xml_parser_create($encoding);
 156    xml_parser_set_option($xml_parser, XML_OPTION_TARGET_ENCODING, 'utf-8');
 157    return $xml_parser;
 158  }
 159  
 160  /**
 161   * Convert data to UTF-8
 162   *
 163   * Requires the iconv, GNU recode or mbstring PHP extension.
 164   *
 165   * @param $data
 166   *   The data to be converted.
 167   * @param $encoding
 168   *   The encoding that the data is in
 169   * @return
 170   *   Converted data or FALSE.
 171   */
 172  function drupal_convert_to_utf8($data, $encoding) {
 173    if (function_exists('iconv')) {
 174      $out = @iconv($encoding, 'utf-8', $data);
 175    }
 176    else if (function_exists('mb_convert_encoding')) {
 177      $out = @mb_convert_encoding($data, 'utf-8', $encoding);
 178    }
 179    else if (function_exists('recode_string')) {
 180      $out = @recode_string($encoding .'..utf-8', $data);
 181    }
 182    else {
 183      watchdog('php', 'Unsupported encoding %s. Please install iconv, GNU recode or mbstring for PHP.', array('%s' => $encoding), WATCHDOG_ERROR);
 184      return FALSE;
 185    }
 186  
 187    return $out;
 188  }
 189  
 190  /**
 191   * Truncate a UTF-8-encoded string safely to a number of bytes.
 192   *
 193   * If the end position is in the middle of a UTF-8 sequence, it scans backwards
 194   * until the beginning of the byte sequence.
 195   *
 196   * Use this function whenever you want to chop off a string at an unsure
 197   * location. On the other hand, if you're sure that you're splitting on a
 198   * character boundary (e.g. after using strpos() or similar), you can safely use
 199   * substr() instead.
 200   *
 201   * @param $string
 202   *   The string to truncate.
 203   * @param $len
 204   *   An upper limit on the returned string length.
 205   * @return
 206   *   The truncated string.
 207   */
 208  function drupal_truncate_bytes($string, $len) {
 209    if (strlen($string) <= $len) {
 210      return $string;
 211    }
 212    if ((ord($string[$len]) < 0x80) || (ord($string[$len]) >= 0xC0)) {
 213      return substr($string, 0, $len);
 214    }
 215    while (--$len >= 0 && ord($string[$len]) >= 0x80 && ord($string[$len]) < 0xC0) {};
 216    return substr($string, 0, $len);
 217  }
 218  
 219  /**
 220   * Truncate a UTF-8-encoded string safely to a number of characters.
 221   *
 222   * @param $string
 223   *   The string to truncate.
 224   * @param $len
 225   *   An upper limit on the returned string length.
 226   * @param $wordsafe
 227   *   Flag to truncate at last space within the upper limit. Defaults to FALSE.
 228   * @param $dots
 229   *   Flag to add trailing dots. Defaults to FALSE.
 230   * @return
 231   *   The truncated string.
 232   */
 233  function truncate_utf8($string, $len, $wordsafe = FALSE, $dots = FALSE) {
 234  
 235    if (drupal_strlen($string) <= $len) {
 236      return $string;
 237    }
 238  
 239    if ($dots) {
 240      $len -= 4;
 241    }
 242  
 243    if ($wordsafe) {
 244      $string = drupal_substr($string, 0, $len + 1); // leave one more character
 245      if ($last_space = strrpos($string, ' ')) { // space exists AND is not on position 0
 246        $string = substr($string, 0, $last_space);
 247      }
 248      else {
 249        $string = drupal_substr($string, 0, $len);
 250      }
 251    }
 252    else {
 253      $string = drupal_substr($string, 0, $len);
 254    }
 255  
 256    if ($dots) {
 257      $string .= ' ...';
 258    }
 259  
 260    return $string;
 261  }
 262  
 263  /**
 264   * Encodes MIME/HTTP header values that contain non-ASCII, UTF-8 encoded
 265   * characters.
 266   *
 267   * For example, mime_header_encode('tést.txt') returns "=?UTF-8?B?dMOpc3QudHh0?=".
 268   *
 269   * See http://www.rfc-editor.org/rfc/rfc2047.txt for more information.
 270   *
 271   * Notes:
 272   * - Only encode strings that contain non-ASCII characters.
 273   * - We progressively cut-off a chunk with truncate_utf8(). This is to ensure
 274   *   each chunk starts and ends on a character boundary.
 275   * - Using \n as the chunk separator may cause problems on some systems and may
 276   *   have to be changed to \r\n or \r.
 277   */
 278  function mime_header_encode($string) {
 279    if (preg_match('/[^\x20-\x7E]/', $string)) {
 280      $chunk_size = 47; // floor((75 - strlen("=?UTF-8?B??=")) * 0.75);
 281      $len = strlen($string);
 282      $output = '';
 283      while ($len > 0) {
 284        $chunk = drupal_truncate_bytes($string, $chunk_size);
 285        $output .= ' =?UTF-8?B?'. base64_encode($chunk) ."?=\n";
 286        $c = strlen($chunk);
 287        $string = substr($string, $c);
 288        $len -= $c;
 289      }
 290      return trim($output);
 291    }
 292    return $string;
 293  }
 294  
 295  /**
 296   * Complement to mime_header_encode
 297   */
 298  function mime_header_decode($header) {
 299    // First step: encoded chunks followed by other encoded chunks (need to collapse whitespace)
 300    $header = preg_replace_callback('/=\?([^?]+)\?(Q|B)\?([^?]+|\?(?!=))\?=\s+(?==\?)/', '_mime_header_decode', $header);
 301    // Second step: remaining chunks (do not collapse whitespace)
 302    return preg_replace_callback('/=\?([^?]+)\?(Q|B)\?([^?]+|\?(?!=))\?=/', '_mime_header_decode', $header);
 303  }
 304  
 305  /**
 306   * Helper function to mime_header_decode
 307   */
 308  function _mime_header_decode($matches) {
 309    // Regexp groups:
 310    // 1: Character set name
 311    // 2: Escaping method (Q or B)
 312    // 3: Encoded data
 313    $data = ($matches[2] == 'B') ? base64_decode($matches[3]) : str_replace('_', ' ', quoted_printable_decode($matches[3]));
 314    if (strtolower($matches[1]) != 'utf-8') {
 315      $data = drupal_convert_to_utf8($data, $matches[1]);
 316    }
 317    return $data;
 318  }
 319  
 320  /**
 321   * Decodes all HTML entities (including numerical ones) to regular UTF-8 bytes.
 322   *
 323   * Double-escaped entities will only be decoded once ("&amp;lt;" becomes "&lt;",
 324   * not "<"). Be careful when using this function, as decode_entities can revert
 325   * previous sanitization efforts (&lt;script&gt; will become <script>).
 326   *
 327   * @param $text
 328   *   The text to decode entities in.
 329   * @param $exclude
 330   *   An array of characters which should not be decoded. For example,
 331   *   array('<', '&', '"'). This affects both named and numerical entities.
 332   *
 333   * @return
 334   *   The input $text, with all HTML entities decoded once.
 335   */
 336  function decode_entities($text, $exclude = array()) {
 337    static $html_entities;
 338    if (!isset($html_entities)) {
 339      include_once  './includes/unicode.entities.inc';
 340    }
 341  
 342    // Flip the exclude list so that we can do quick lookups later.
 343    $exclude = array_flip($exclude);
 344  
 345    // Use a regexp to select all entities in one pass, to avoid decoding 
 346    // double-escaped entities twice. The PREG_REPLACE_EVAL modifier 'e' is
 347    // being used to allow for a callback (see 
 348    // http://php.net/manual/en/reference.pcre.pattern.modifiers).
 349    return preg_replace('/&(#x?)?([A-Za-z0-9]+);/e', '_decode_entities("$1", "$2", "$0", $html_entities, $exclude)', $text);
 350  }
 351  
 352  /**
 353   * Helper function for decode_entities
 354   */
 355  function _decode_entities($prefix, $codepoint, $original, &$html_entities, &$exclude) {
 356    // Named entity
 357    if (!$prefix) {
 358      // A named entity not in the exclude list.
 359      if (isset($html_entities[$original]) && !isset($exclude[$html_entities[$original]])) {
 360        return $html_entities[$original];
 361      }
 362      else {
 363        return $original;
 364      }
 365    }
 366    // Hexadecimal numerical entity
 367    if ($prefix == '#x') {
 368      $codepoint = base_convert($codepoint, 16, 10);
 369    }
 370    // Decimal numerical entity (strip leading zeros to avoid PHP octal notation)
 371    else {
 372      $codepoint = preg_replace('/^0+/', '', $codepoint);
 373    }
 374    // Encode codepoint as UTF-8 bytes
 375    if ($codepoint < 0x80) {
 376      $str = chr($codepoint);
 377    }
 378    else if ($codepoint < 0x800) {
 379      $str = chr(0xC0 | ($codepoint >> 6))
 380           . chr(0x80 | ($codepoint & 0x3F));
 381    }
 382    else if ($codepoint < 0x10000) {
 383      $str = chr(0xE0 | ( $codepoint >> 12))
 384           . chr(0x80 | (($codepoint >> 6) & 0x3F))
 385           . chr(0x80 | ( $codepoint       & 0x3F));
 386    }
 387    else if ($codepoint < 0x200000) {
 388      $str = chr(0xF0 | ( $codepoint >> 18))
 389           . chr(0x80 | (($codepoint >> 12) & 0x3F))
 390           . chr(0x80 | (($codepoint >> 6)  & 0x3F))
 391           . chr(0x80 | ( $codepoint        & 0x3F));
 392    }
 393    // Check for excluded characters
 394    if (isset($exclude[$str])) {
 395      return $original;
 396    }
 397    else {
 398      return $str;
 399    }
 400  }
 401  
 402  /**
 403   * Count the amount of characters in a UTF-8 string. This is less than or
 404   * equal to the byte count.
 405   */
 406  function drupal_strlen($text) {
 407    global $multibyte;
 408    if ($multibyte == UNICODE_MULTIBYTE) {
 409      return mb_strlen($text);
 410    }
 411    else {
 412      // Do not count UTF-8 continuation bytes.
 413      return strlen(preg_replace("/[\x80-\xBF]/", '', $text));
 414    }
 415  }
 416  
 417  /**
 418   * Uppercase a UTF-8 string.
 419   */
 420  function drupal_strtoupper($text) {
 421    global $multibyte;
 422    if ($multibyte == UNICODE_MULTIBYTE) {
 423      return mb_strtoupper($text);
 424    }
 425    else {
 426      // Use C-locale for ASCII-only uppercase
 427      $text = strtoupper($text);
 428      // Case flip Latin-1 accented letters
 429      $text = preg_replace_callback('/\xC3[\xA0-\xB6\xB8-\xBE]/', '_unicode_caseflip', $text);
 430      return $text;
 431    }
 432  }
 433  
 434  /**
 435   * Lowercase a UTF-8 string.
 436   */
 437  function drupal_strtolower($text) {
 438    global $multibyte;
 439    if ($multibyte == UNICODE_MULTIBYTE) {
 440      return mb_strtolower($text);
 441    }
 442    else {
 443      // Use C-locale for ASCII-only lowercase
 444      $text = strtolower($text);
 445      // Case flip Latin-1 accented letters
 446      $text = preg_replace_callback('/\xC3[\x80-\x96\x98-\x9E]/', '_unicode_caseflip', $text);
 447      return $text;
 448    }
 449  }
 450  
 451  /**
 452   * Helper function for case conversion of Latin-1.
 453   * Used for flipping U+C0-U+DE to U+E0-U+FD and back.
 454   */
 455  function _unicode_caseflip($matches) {
 456    return $matches[0][0] . chr(ord($matches[0][1]) ^ 32);
 457  }
 458  
 459  /**
 460   * Capitalize the first letter of a UTF-8 string.
 461   */
 462  function drupal_ucfirst($text) {
 463    // Note: no mbstring equivalent!
 464    return drupal_strtoupper(drupal_substr($text, 0, 1)) . drupal_substr($text, 1);
 465  }
 466  
 467  /**
 468   * Cut off a piece of a string based on character indices and counts. Follows
 469   * the same behavior as PHP's own substr() function.
 470   *
 471   * Note that for cutting off a string at a known character/substring
 472   * location, the usage of PHP's normal strpos/substr is safe and
 473   * much faster.
 474   */
 475  function drupal_substr($text, $start, $length = NULL) {
 476    global $multibyte;
 477    if ($multibyte == UNICODE_MULTIBYTE) {
 478      return $length === NULL ? mb_substr($text, $start) : mb_substr($text, $start, $length);
 479    }
 480    else {
 481      $strlen = strlen($text);
 482      // Find the starting byte offset
 483      $bytes = 0;
 484      if ($start > 0) {
 485        // Count all the continuation bytes from the start until we have found
 486        // $start characters
 487        $bytes = -1; $chars = -1;
 488        while ($bytes < $strlen && $chars < $start) {
 489          $bytes++;
 490          $c = ord($text[$bytes]);
 491          if ($c < 0x80 || $c >= 0xC0) {
 492            $chars++;
 493          }
 494        }
 495      }
 496      else if ($start < 0) {
 497        // Count all the continuation bytes from the end until we have found
 498        // abs($start) characters
 499        $start = abs($start);
 500        $bytes = $strlen; $chars = 0;
 501        while ($bytes > 0 && $chars < $start) {
 502          $bytes--;
 503          $c = ord($text[$bytes]);
 504          if ($c < 0x80 || $c >= 0xC0) {
 505            $chars++;
 506          }
 507        }
 508      }
 509      $istart = $bytes;
 510  
 511      // Find the ending byte offset
 512      if ($length === NULL) {
 513        $bytes = $strlen - 1;
 514      }
 515      else if ($length > 0) {
 516        // Count all the continuation bytes from the starting index until we have
 517        // found $length + 1 characters. Then backtrack one byte.
 518        $bytes = $istart; $chars = 0;
 519        while ($bytes < $strlen && $chars < $length) {
 520          $bytes++;
 521          $c = ord($text[$bytes]);
 522          if ($c < 0x80 || $c >= 0xC0) {
 523            $chars++;
 524          }
 525        }
 526        $bytes--;
 527      }
 528      else if ($length < 0) {
 529        // Count all the continuation bytes from the end until we have found
 530        // abs($length) characters
 531        $length = abs($length);
 532        $bytes = $strlen - 1; $chars = 0;
 533        while ($bytes >= 0 && $chars < $length) {
 534          $c = ord($text[$bytes]);
 535          if ($c < 0x80 || $c >= 0xC0) {
 536            $chars++;
 537          }
 538          $bytes--;
 539        }
 540      }
 541      $iend = $bytes;
 542  
 543      return substr($text, $istart, max(0, $iend - $istart + 1));
 544    }
 545  }
 546  
 547  


Generated: Mon Jul 9 18:01:44 2012 Cross-referenced by PHPXref 0.7