squirrelmail/functions/encode/us_ascii.php
2025-01-03 11:47:03 -08:00

50 lines
1.3 KiB
PHP

<?php
/**
* us_ascii encoding functions
*
* takes a string of unicode entities and converts it to a us-ascii encoded string
* Unsupported characters are replaced with ?.
*
* @copyright 2004-2025 The SquirrelMail Project Team
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
* @version $Id$
* @package squirrelmail
* @subpackage encode
*/
/**
* Converts string to us-ascii
* @param string $string text with numeric unicode entities
* @return string us-ascii encoded text
*/
function charset_encode_us_ascii ($string) {
// don't run encoding function, if there is no encoded characters
if (! preg_match("'&#[0-9]+;'",$string) ) return $string;
$string=preg_replace_callback("/&#([0-9]+);/",'unicodetousascii',$string);
return $string;
}
/**
* Return us-ascii symbol when unicode character number is provided
*
* This function is used internally by charset_encode_us_ascii
* function. It might be unavailable to other SquirrelMail functions.
* Don't use it or make sure, that functions/encode/us_ascii.php is
* included.
*
* @param array $matches array with first element a decimal unicode value
* @return string us-ascii character
*/
function unicodetousascii($matches) {
$var = $matches[1];
if ($var < 128) {
$ret = chr ($var);
} else {
$ret='?';
}
return $ret;
}