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 2004-2021 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     $string=preg_replace_callback("/&#([0-9]+);/",'unicodetousascii',$string);
  26
  27     return $string;
  28 }
  29
  30 /**
  31  * Return us-ascii symbol when unicode character number is provided
  32  *
  33  * This function is used internally by charset_encode_us_ascii
  34  * function. It might be unavailable to other SquirrelMail functions.
  35  * Don't use it or make sure, that functions/encode/us_ascii.php is
  36  * included.
  37  *
  38  * @param array $matches array with first element a decimal unicode value
  39  * @return string us-ascii character
  40  */
  41 function unicodetousascii($matches) {
  42     $var = $matches[1];
  43
  44     if ($var < 128) {
  45         $ret = chr ($var);
  46     } else {
  47         $ret='?';
  48     }
  49     return $ret;
  50 }