functions/encode/us_ascii.php

   1 <?php
   2
   3 /**
   4  * us_ascii encoding functions
   5  *
   6  * takes a string of unicode entities and converts it to a us-ascii encoded string
   7  * Unsupported characters are replaced with ?.
   8  *
   9  * @copyright 2004-2010 The SquirrelMail Project Team
  10  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  11  * @version $Id$
  12  * @package squirrelmail
  13  * @subpackage encode
  14  */
  15
  16 /**
  17  * Converts string to us-ascii
  18  * @param string $string text with numeric unicode entities
  19  * @return string us-ascii encoded text
  20  */
  21 function charset_encode_us_ascii ($string) {
  22    // don't run encoding function, if there is no encoded characters
  23    if (! preg_match("'&#[0-9]+;'",$string) ) return $string;
  24
  25     $string=preg_replace("/&#([0-9]+);/e","unicodetousascii('\\1')",$string);
  26     // $string=preg_replace("/&#[xX]([0-9A-F]+);/e","unicodetousascii(hexdec('\\1'))",$string);
  27
  28     return $string;
  29 }
  30
  31 /**
  32  * Return us-ascii symbol when unicode character number is provided
  33  *
  34  * This function is used internally by charset_encode_us_ascii
  35  * function. It might be unavailable to other SquirrelMail functions.
  36  * Don't use it or make sure, that functions/encode/us_ascii.php is
  37  * included.
  38  *
  39  * @param int $var decimal unicode value
  40  * @return string us-ascii character
  41  */
  42 function unicodetousascii($var) {
  43
  44     if ($var < 128) {
  45         $ret = chr ($var);
  46     } else {
  47         $ret='?';
  48     }
  49     return $ret;
  50 }