adding iso-8859-1 and us-ascii encoding support

functions/encode/iso_8859_1.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * iso-8859-1 encoding functions
+ *
+ * takes a string of unicode entities and converts it to a iso-8859-1 encoded string
+ * Unsupported characters are replaced with ?.
+ *
+ * @version $Id$
+ * @copyright Copyright &copy; SquirrelMail Development Team, 2004
+ * @package squirrelmail
+ * @subpackage encode
+ */
+
+/**
+ * Converts string to iso-8859-1
+ * @param string $string text with numeric unicode entities
+ * @return string iso-8859-1 encoded text
+ */
+function charset_encode_iso_8859_1 ($string) {
+   // don't run encoding function, if there is no encoded characters
+   if (! preg_match("'&#[0-9]+;'",$string) ) return $string;
+
+    $string=preg_replace("/&#([0-9]+);/e","unicodetoiso88591('\\1')",$string);
+    // $string=preg_replace("/&#[xX]([0-9A-F]+);/e","unicodetoiso88591(hexdec('\\1'))",$string);
+    
+    return $string;
+}
+
+/**
+ * Return iso-8859-1 symbol when unicode character number is provided
+ * 
+ * This function is used internally by charset_encode_iso_8859_1 
+ * function. It might be unavailable to other squirrelmail functions.
+ * Don't use it or make sure, that functions/encode/iso_8859_1.php is 
+ * included. 
+ *
+ * @param int $var decimal unicode value
+ * @return string iso-8859-1 character
+ */
+function unicodetoiso88591($var) {
+
+    if ($var < 256) {
+        $ret = chr ($var);
+    } else {
+        $ret='?';
+    }
+    return $ret;
+}
+?>

functions/encode/us_ascii.php

@@ -0,0 +1,49 @@
+<?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 ?.
+ *
+ * @version $Id$
+ * @copyright Copyright &copy; SquirrelMail Development Team, 2004
+ * @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;
+
+    $string=preg_replace("/&#([0-9]+);/e","unicodetousascii('\\1')",$string);
+    // $string=preg_replace("/&#[xX]([0-9A-F]+);/e","unicodetousascii(hexdec('\\1'))",$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 int $var decimal unicode value
+ * @return string us-ascii character
+ */
+function unicodetousascii($var) {
+
+    if ($var < 128) {
+        $ret = chr ($var);
+    } else {
+        $ret='?';
+    }
+    return $ret;
+}
+?>