functions/encode/utf_8.php

   1 <?php
   2 /**
   3  * utf-8 encoding functions
   4  *
   5  * takes a string of unicode entities and converts it to a utf-8 encoded string
   6  * each unicode entitiy has the form &#nnn(nn); n={0..9} and can be displayed by utf-8 supporting
   7  * browsers. Ascii will not be modified.
   8  *
   9  * Original code is taken from www.php.net manual comments
  10  * Original author: ronen at greyzone dot com
  11  *
  12  * @version $Id$
  13  * @copyright Copyright &copy; SquirrelMail Development Team, 2004
  14  * @package squirrelmail
  15  * @subpackage encode
  16  */
  17
  18 /**
  19  * Converts string to utf-8
  20  * @param string $string text with numeric unicode entities
  21  * @return string utf-8 encoded text
  22  */
  23 function charset_encode_utf_8 ($string) {
  24    // don't run encoding function, if there is no encoded characters
  25    if (! preg_match("'&#[0-9]+;'",$string) ) return $string;
  26
  27     $string=preg_replace("/&#([0-9]+);/e","unicodetoutf8('\\1')",$string);
  28     // $string=preg_replace("/&#[xX]([0-9A-F]+);/e","unicodetoutf8(hexdec('\\1'))",$string);
  29
  30     return $string;
  31 }
  32
  33 /**
  34  * Return utf8 symbol when unicode character number is provided
  35  *
  36  * This function is used internally by charset_encode_utf_8
  37  * function. It might be unavailable to other squirrelmail functions.
  38  * Don't use it or make sure, that functions/encode/utf_8.php is
  39  * included.
  40  *
  41  * @param int $var decimal unicode value
  42  * @return string utf8 character
  43  */
  44 function unicodetoutf8($var) {
  45
  46     if ($var < 128) {
  47         $ret = chr ($var);
  48     } else if ($var < 2048) {
  49         // Two byte utf-8
  50         $binVal = str_pad (decbin ($var), 11, "0", STR_PAD_LEFT);
  51         $binPart1 = substr ($binVal, 0, 5);
  52         $binPart2 = substr ($binVal, 5);
  53
  54         $char1 = chr (192 + bindec ($binPart1));
  55         $char2 = chr (128 + bindec ($binPart2));
  56         $ret = $char1 . $char2;
  57     } else if ($var < 65536) {
  58         // Three byte utf-8
  59         $binVal = str_pad (decbin ($var), 16, "0", STR_PAD_LEFT);
  60         $binPart1 = substr ($binVal, 0, 4);
  61         $binPart2 = substr ($binVal, 4, 6);
  62         $binPart3 = substr ($binVal, 10);
  63
  64         $char1 = chr (224 + bindec ($binPart1));
  65         $char2 = chr (128 + bindec ($binPart2));
  66         $char3 = chr (128 + bindec ($binPart3));
  67         $ret = $char1 . $char2 . $char3;
  68     } else if ($var < 2097152) {
  69         // Four byte utf-8
  70         $binVal = str_pad (decbin ($var), 21, "0", STR_PAD_LEFT);
  71         $binPart1 = substr ($binVal, 0, 3);
  72         $binPart2 = substr ($binVal, 3, 6);
  73         $binPart3 = substr ($binVal, 9, 6);
  74         $binPart4 = substr ($binVal, 15);
  75
  76         $char1 = chr (240 + bindec ($binPart1));
  77         $char2 = chr (128 + bindec ($binPart2));
  78         $char3 = chr (128 + bindec ($binPart3));
  79         $char4 = chr (128 + bindec ($binPart4));
  80         $ret = $char1 . $char2 . $char3 . $char4;
  81     } else if ($var < 67108864) {
  82         // Five byte utf-8
  83         $binVal = str_pad (decbin ($var), 26, "0", STR_PAD_LEFT);
  84         $binPart1 = substr ($binVal, 0, 2);
  85         $binPart2 = substr ($binVal, 2, 6);
  86         $binPart3 = substr ($binVal, 8, 6);
  87         $binPart4 = substr ($binVal, 14,6);
  88         $binPart5 = substr ($binVal, 20);
  89
  90         $char1 = chr (248 + bindec ($binPart1));
  91         $char2 = chr (128 + bindec ($binPart2));
  92         $char3 = chr (128 + bindec ($binPart3));
  93         $char4 = chr (128 + bindec ($binPart4));
  94         $char5 = chr (128 + bindec ($binPart5));
  95         $ret = $char1 . $char2 . $char3 . $char4 . $char5;
  96     } else if ($var < 2147483648) {
  97         // Six byte utf-8
  98         $binVal = str_pad (decbin ($var), 31, "0", STR_PAD_LEFT);
  99         $binPart1 = substr ($binVal, 0, 1);
 100         $binPart2 = substr ($binVal, 1, 6);
 101         $binPart3 = substr ($binVal, 7, 6);
 102         $binPart4 = substr ($binVal, 13,6);
 103         $binPart5 = substr ($binVal, 19,6);
 104         $binPart6 = substr ($binVal, 25);
 105
 106         $char1 = chr (252 + bindec ($binPart1));
 107         $char2 = chr (128 + bindec ($binPart2));
 108         $char3 = chr (128 + bindec ($binPart3));
 109         $char4 = chr (128 + bindec ($binPart4));
 110         $char5 = chr (128 + bindec ($binPart5));
 111         $char6 = chr (128 + bindec ($binPart6));
 112         $ret = $char1 . $char2 . $char3 . $char4 . $char5 . $char6;
 113     } else {
 114         // there is no such symbol in utf-8
 115         $ret='?';
 116     }
 117     return $ret;
 118 }
 119 ?>