function_exists checks in utf8 lib for compatibility with 3rd party libs

The DokuWiki UTF-8 library and its derivates are very popular in Open Source
PHP software. This makes trouble due to name clashes, when 3rd party
software libraries need to be loaded within DokuWiki.

A common example is using the authentication libraries of popular forum
systems (PHP3, PunBB3).

With the checks added, DokuWiki will rely on the 3rd party UTF-8 functions
instead of its own ones. As long as they are really the same, this will
work.

Users of 3rd party libs need to check compatibility between implementations
themselves.

darcs-hash:20090114201824-7ad00-40fcc2e1abec42adabef5596a6617fbaa22291d5.gz

1 files changed, 806 insertions, 748 deletions

diff --git a/inc/utf8.php b/inc/utf8.php
index 96d676cfb..e2f016942 100644
--- a/inc/utf8.php
+++ b/inc/utf8.php
@@ -19,883 +19,941 @@ if(!defined('UTF8_MBSTRING')){
 
 if(UTF8_MBSTRING){ mb_internal_encoding('UTF-8'); }
 
-
-/**
- * URL-Encode a filename to allow unicodecharacters
- *
- * Slashes are not encoded
- *
- * When the second parameter is true the string will
- * be encoded only if non ASCII characters are detected -
- * This makes it safe to run it multiple times on the
- * same string (default is true)
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    urlencode
- */
-function utf8_encodeFN($file,$safe=true){
-  if($safe && preg_match('#^[a-zA-Z0-9/_\-.%]+$#',$file)){
-    return $file;
-  }
-  $file = urlencode($file);
-  $file = str_replace('%2F','/',$file);
-  return $file;
-}
-
-/**
- * URL-Decode a filename
- *
- * This is just a wrapper around urldecode
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    urldecode
- */
-function utf8_decodeFN($file){
-  $file = urldecode($file);
-  return $file;
-}
-
-/**
- * Checks if a string contains 7bit ASCII only
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- */
-function utf8_isASCII($str){
-  for($i=0; $i<strlen($str); $i++){
-    if(ord($str{$i}) >127) return false;
-  }
-  return true;
+if(!function_exists('utf8_encodeFN')){
+    /**
+     * URL-Encode a filename to allow unicodecharacters
+     *
+     * Slashes are not encoded
+     *
+     * When the second parameter is true the string will
+     * be encoded only if non ASCII characters are detected -
+     * This makes it safe to run it multiple times on the
+     * same string (default is true)
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    urlencode
+     */
+    function utf8_encodeFN($file,$safe=true){
+      if($safe && preg_match('#^[a-zA-Z0-9/_\-.%]+$#',$file)){
+        return $file;
+      }
+      $file = urlencode($file);
+      $file = str_replace('%2F','/',$file);
+      return $file;
+    }
 }
 
-/**
- * Strips all highbyte chars
- *
- * Returns a pure ASCII7 string
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- */
-function utf8_strip($str){
-  $ascii = '';
-  for($i=0; $i<strlen($str); $i++){
-    if(ord($str{$i}) <128){
-      $ascii .= $str{$i};
+if(!function_exists('utf8_decodeFN')){
+    /**
+     * URL-Decode a filename
+     *
+     * This is just a wrapper around urldecode
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    urldecode
+     */
+    function utf8_decodeFN($file){
+        $file = urldecode($file);
+        return $file;
     }
-  }
-  return $ascii;
 }
 
-/**
- * Tries to detect if a string is in Unicode encoding
- *
- * @author <bmorel@ssi.fr>
- * @link   http://www.php.net/manual/en/function.utf8-encode.php
- */
-function utf8_check($Str) {
- for ($i=0; $i<strlen($Str); $i++) {
-  $b = ord($Str[$i]);
-  if ($b < 0x80) continue; # 0bbbbbbb
-  elseif (($b & 0xE0) == 0xC0) $n=1; # 110bbbbb
-  elseif (($b & 0xF0) == 0xE0) $n=2; # 1110bbbb
-  elseif (($b & 0xF8) == 0xF0) $n=3; # 11110bbb
-  elseif (($b & 0xFC) == 0xF8) $n=4; # 111110bb
-  elseif (($b & 0xFE) == 0xFC) $n=5; # 1111110b
-  else return false; # Does not match any model
-  for ($j=0; $j<$n; $j++) { # n bytes matching 10bbbbbb follow ?
-   if ((++$i == strlen($Str)) || ((ord($Str[$i]) & 0xC0) != 0x80))
-   return false;
-  }
- }
- return true;
+if(!function_exists('utf8_isASCII')){
+    /**
+     * Checks if a string contains 7bit ASCII only
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     */
+    function utf8_isASCII($str){
+      for($i=0; $i<strlen($str); $i++){
+        if(ord($str{$i}) >127) return false;
+      }
+      return true;
+    }
 }
 
-/**
- * Unicode aware replacement for strlen()
- *
- * utf8_decode() converts characters that are not in ISO-8859-1
- * to '?', which, for the purpose of counting, is alright - It's
- * even faster than mb_strlen.
- *
- * @author <chernyshevsky at hotmail dot com>
- * @see    strlen()
- * @see    utf8_decode()
- */
-function utf8_strlen($string){
-  return strlen(utf8_decode($string));
+if(!function_exists('utf8_strip')){
+    /**
+     * Strips all highbyte chars
+     *
+     * Returns a pure ASCII7 string
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     */
+    function utf8_strip($str){
+      $ascii = '';
+      for($i=0; $i<strlen($str); $i++){
+        if(ord($str{$i}) <128){
+          $ascii .= $str{$i};
+        }
+      }
+      return $ascii;
+    }
 }
 
-/**
- * UTF-8 aware alternative to substr
- *
- * Return part of a string given character offset (and optionally length)
- *
- * @author Harry Fuecks <hfuecks@gmail.com>
- * @author Chris Smith <chris@jalakai.co.uk>
- * @param string
- * @param integer number of UTF-8 characters offset (from left)
- * @param integer (optional) length in UTF-8 characters from offset
- * @return mixed string or false if failure
- */
-function utf8_substr($str, $offset, $length = null) {
-    if(UTF8_MBSTRING){
-        if( $length === null ){
-            return mb_substr($str, $offset);
-        }else{
-            return mb_substr($str, $offset, $length);
+if(!function_exists('utf8_check')){
+    /**
+     * Tries to detect if a string is in Unicode encoding
+     *
+     * @author <bmorel@ssi.fr>
+     * @link   http://www.php.net/manual/en/function.utf8-encode.php
+     */
+    function utf8_check($Str) {
+        for ($i=0; $i<strlen($Str); $i++) {
+            $b = ord($Str[$i]);
+            if ($b < 0x80) continue; # 0bbbbbbb
+            elseif (($b & 0xE0) == 0xC0) $n=1; # 110bbbbb
+            elseif (($b & 0xF0) == 0xE0) $n=2; # 1110bbbb
+            elseif (($b & 0xF8) == 0xF0) $n=3; # 11110bbb
+            elseif (($b & 0xFC) == 0xF8) $n=4; # 111110bb
+            elseif (($b & 0xFE) == 0xFC) $n=5; # 1111110b
+            else return false; # Does not match any model
+
+            for ($j=0; $j<$n; $j++) { # n bytes matching 10bbbbbb follow ?
+                if ((++$i == strlen($Str)) || ((ord($Str[$i]) & 0xC0) != 0x80))
+                    return false;
+            }
         }
+        return true;
     }
+}
 
-    /*
-     * Notes:
+if(!function_exists('utf8_strlen')){
+    /**
+     * Unicode aware replacement for strlen()
      *
-     * no mb string support, so we'll use pcre regex's with 'u' flag
-     * pcre only supports repetitions of less than 65536, in order to accept up to MAXINT values for
-     * offset and length, we'll repeat a group of 65535 characters when needed (ok, up to MAXINT-65536)
+     * utf8_decode() converts characters that are not in ISO-8859-1
+     * to '?', which, for the purpose of counting, is alright - It's
+     * even faster than mb_strlen.
      *
-     * substr documentation states false can be returned in some cases (e.g. offset > string length)
-     * mb_substr never returns false, it will return an empty string instead.
-     *
-     * calculating the number of characters in the string is a relatively expensive operation, so
-     * we only carry it out when necessary. It isn't necessary for +ve offsets and no specified length
+     * @author <chernyshevsky at hotmail dot com>
+     * @see    strlen()
+     * @see    utf8_decode()
      */
+    function utf8_strlen($string){
+        return strlen(utf8_decode($string));
+    }
+}
 
-    // cast parameters to appropriate types to avoid multiple notices/warnings
-    $str = (string)$str;                          // generates E_NOTICE for PHP4 objects, but not PHP5 objects
-    $offset = (int)$offset;
-    if (!is_null($length)) $length = (int)$length;
-
-    // handle trivial cases
-    if ($length === 0) return '';
-    if ($offset < 0 && $length < 0 && $length < $offset) return '';
+if(!function_exists('utf8_substr')){
+    /**
+     * UTF-8 aware alternative to substr
+     *
+     * Return part of a string given character offset (and optionally length)
+     *
+     * @author Harry Fuecks <hfuecks@gmail.com>
+     * @author Chris Smith <chris@jalakai.co.uk>
+     * @param string
+     * @param integer number of UTF-8 characters offset (from left)
+     * @param integer (optional) length in UTF-8 characters from offset
+     * @return mixed string or false if failure
+     */
+    function utf8_substr($str, $offset, $length = null) {
+        if(UTF8_MBSTRING){
+            if( $length === null ){
+                return mb_substr($str, $offset);
+            }else{
+                return mb_substr($str, $offset, $length);
+            }
+        }
 
-    $offset_pattern = '';
-    $length_pattern = '';
+        /*
+         * Notes:
+         *
+         * no mb string support, so we'll use pcre regex's with 'u' flag
+         * pcre only supports repetitions of less than 65536, in order to accept up to MAXINT values for
+         * offset and length, we'll repeat a group of 65535 characters when needed (ok, up to MAXINT-65536)
+         *
+         * substr documentation states false can be returned in some cases (e.g. offset > string length)
+         * mb_substr never returns false, it will return an empty string instead.
+         *
+         * calculating the number of characters in the string is a relatively expensive operation, so
+         * we only carry it out when necessary. It isn't necessary for +ve offsets and no specified length
+         */
+
+        // cast parameters to appropriate types to avoid multiple notices/warnings
+        $str = (string)$str;                          // generates E_NOTICE for PHP4 objects, but not PHP5 objects
+        $offset = (int)$offset;
+        if (!is_null($length)) $length = (int)$length;
+
+        // handle trivial cases
+        if ($length === 0) return '';
+        if ($offset < 0 && $length < 0 && $length < $offset) return '';
+
+        $offset_pattern = '';
+        $length_pattern = '';
+
+        // normalise -ve offsets (we could use a tail anchored pattern, but they are horribly slow!)
+        if ($offset < 0) {
+          $strlen = strlen(utf8_decode($str));        // see notes
+          $offset = $strlen + $offset;
+          if ($offset < 0) $offset = 0;
+        }
 
-    // normalise -ve offsets (we could use a tail anchored pattern, but they are horribly slow!)
-    if ($offset < 0) {
-      $strlen = strlen(utf8_decode($str));        // see notes
-      $offset = $strlen + $offset;
-      if ($offset < 0) $offset = 0;
-    }
+        // establish a pattern for offset, a non-captured group equal in length to offset
+        if ($offset > 0) {
+          $Ox = (int)($offset/65535);
+          $Oy = $offset%65535;
 
-    // establish a pattern for offset, a non-captured group equal in length to offset
-    if ($offset > 0) {
-      $Ox = (int)($offset/65535);
-      $Oy = $offset%65535;
+          if ($Ox) $offset_pattern = '(?:.{65535}){'.$Ox.'}';
+          $offset_pattern = '^(?:'.$offset_pattern.'.{'.$Oy.'})';
+        } else {
+          $offset_pattern = '^';                      // offset == 0; just anchor the pattern
+        }
 
-      if ($Ox) $offset_pattern = '(?:.{65535}){'.$Ox.'}';
-      $offset_pattern = '^(?:'.$offset_pattern.'.{'.$Oy.'})';
-    } else {
-      $offset_pattern = '^';                      // offset == 0; just anchor the pattern
-    }
+        // establish a pattern for length
+        if (is_null($length)) {
+          $length_pattern = '(.*)$';                  // the rest of the string
+        } else {
 
-    // establish a pattern for length
-    if (is_null($length)) {
-      $length_pattern = '(.*)$';                  // the rest of the string
-    } else {
+          if (!isset($strlen)) $strlen = strlen(utf8_decode($str));    // see notes
+          if ($offset > $strlen) return '';           // another trivial case
 
-      if (!isset($strlen)) $strlen = strlen(utf8_decode($str));    // see notes
-      if ($offset > $strlen) return '';           // another trivial case
+          if ($length > 0) {
 
-      if ($length > 0) {
+            $length = min($strlen-$offset, $length);  // reduce any length that would go passed the end of the string
 
-        $length = min($strlen-$offset, $length);  // reduce any length that would go passed the end of the string
+            $Lx = (int)($length/65535);
+            $Ly = $length%65535;
 
-        $Lx = (int)($length/65535);
-        $Ly = $length%65535;
+            // +ve length requires ... a captured group of length characters
+            if ($Lx) $length_pattern = '(?:.{65535}){'.$Lx.'}';
+            $length_pattern = '('.$length_pattern.'.{'.$Ly.'})';
 
-        // +ve length requires ... a captured group of length characters
-        if ($Lx) $length_pattern = '(?:.{65535}){'.$Lx.'}';
-        $length_pattern = '('.$length_pattern.'.{'.$Ly.'})';
+          } else if ($length < 0) {
 
-      } else if ($length < 0) {
+            if ($length < ($offset - $strlen)) return '';
 
-        if ($length < ($offset - $strlen)) return '';
+            $Lx = (int)((-$length)/65535);
+            $Ly = (-$length)%65535;
 
-        $Lx = (int)((-$length)/65535);
-        $Ly = (-$length)%65535;
+            // -ve length requires ... capture everything except a group of -length characters
+            //                         anchored at the tail-end of the string
+            if ($Lx) $length_pattern = '(?:.{65535}){'.$Lx.'}';
+            $length_pattern = '(.*)(?:'.$length_pattern.'.{'.$Ly.'})$';
+          }
+        }
 
-        // -ve length requires ... capture everything except a group of -length characters
-        //                         anchored at the tail-end of the string
-        if ($Lx) $length_pattern = '(?:.{65535}){'.$Lx.'}';
-        $length_pattern = '(.*)(?:'.$length_pattern.'.{'.$Ly.'})$';
-      }
+        if (!preg_match('#'.$offset_pattern.$length_pattern.'#us',$str,$match)) return '';
+        return $match[1];
     }
-
-    if (!preg_match('#'.$offset_pattern.$length_pattern.'#us',$str,$match)) return '';
-    return $match[1];
 }
 
-/**
- * Unicode aware replacement for substr_replace()
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    substr_replace()
- */
-function utf8_substr_replace($string, $replacement, $start , $length=0 ){
-  $ret = '';
-  if($start>0) $ret .= utf8_substr($string, 0, $start);
-  $ret .= $replacement;
-  $ret .= utf8_substr($string, $start+$length);
-  return $ret;
+if(!function_exists('utf8_substr_replace')){
+    /**
+     * Unicode aware replacement for substr_replace()
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    substr_replace()
+     */
+    function utf8_substr_replace($string, $replacement, $start , $length=0 ){
+      $ret = '';
+      if($start>0) $ret .= utf8_substr($string, 0, $start);
+      $ret .= $replacement;
+      $ret .= utf8_substr($string, $start+$length);
+      return $ret;
+    }
 }
 
-/**
- * Unicode aware replacement for ltrim()
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    ltrim()
- * @return string
- */
-function utf8_ltrim($str,$charlist=''){
-  if($charlist == '') return ltrim($str);
+if(!function_exists('utf8_ltrim')){
+    /**
+     * Unicode aware replacement for ltrim()
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    ltrim()
+     * @return string
+     */
+    function utf8_ltrim($str,$charlist=''){
+      if($charlist == '') return ltrim($str);
 
-  //quote charlist for use in a characterclass
-  $charlist = preg_replace('!([\\\\\\-\\]\\[/])!','\\\${1}',$charlist);
+      //quote charlist for use in a characterclass
+      $charlist = preg_replace('!([\\\\\\-\\]\\[/])!','\\\${1}',$charlist);
 
-  return preg_replace('/^['.$charlist.']+/u','',$str);
+      return preg_replace('/^['.$charlist.']+/u','',$str);
+    }
 }
 
-/**
- * Unicode aware replacement for rtrim()
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    rtrim()
- * @return string
- */
-function  utf8_rtrim($str,$charlist=''){
-  if($charlist == '') return rtrim($str);
+if(!function_exists('utf8_rtrim')){
+    /**
+     * Unicode aware replacement for rtrim()
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    rtrim()
+     * @return string
+     */
+    function  utf8_rtrim($str,$charlist=''){
+      if($charlist == '') return rtrim($str);
 
-  //quote charlist for use in a characterclass
-  $charlist = preg_replace('!([\\\\\\-\\]\\[/])!','\\\${1}',$charlist);
+      //quote charlist for use in a characterclass
+      $charlist = preg_replace('!([\\\\\\-\\]\\[/])!','\\\${1}',$charlist);
 
-  return preg_replace('/['.$charlist.']+$/u','',$str);
+      return preg_replace('/['.$charlist.']+$/u','',$str);
+    }
 }
 
-/**
- * Unicode aware replacement for trim()
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @see    trim()
- * @return string
- */
-function  utf8_trim($str,$charlist='') {
-  if($charlist == '') return trim($str);
+if(!function_exists('utf8_trim')){
+    /**
+     * Unicode aware replacement for trim()
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @see    trim()
+     * @return string
+     */
+    function  utf8_trim($str,$charlist='') {
+      if($charlist == '') return trim($str);
 
-  return utf8_ltrim(utf8_rtrim($str,$charlist),$charlist);
+      return utf8_ltrim(utf8_rtrim($str,$charlist),$charlist);
+    }
 }
 
+if(!function_exists('utf8_strtolower')){
+    /**
+     * This is a unicode aware replacement for strtolower()
+     *
+     * Uses mb_string extension if available
+     *
+     * @author Leo Feyer <leo@typolight.org>
+     * @see    strtolower()
+     * @see    utf8_strtoupper()
+     */
+    function utf8_strtolower($string){
+      if(UTF8_MBSTRING) return mb_strtolower($string,'utf-8');
 
-/**
- * This is a unicode aware replacement for strtolower()
- *
- * Uses mb_string extension if available
- *
- * @author Leo Feyer <leo@typolight.org>
- * @see    strtolower()
- * @see    utf8_strtoupper()
- */
-function utf8_strtolower($string){
-  if(UTF8_MBSTRING) return mb_strtolower($string,'utf-8');
-
-  global $UTF8_UPPER_TO_LOWER;
-  return strtr($string,$UTF8_UPPER_TO_LOWER);
+      global $UTF8_UPPER_TO_LOWER;
+      return strtr($string,$UTF8_UPPER_TO_LOWER);
+    }
 }
 
-/**
- * This is a unicode aware replacement for strtoupper()
- *
- * Uses mb_string extension if available
- *
- * @author Leo Feyer <leo@typolight.org>
- * @see    strtoupper()
- * @see    utf8_strtoupper()
- */
-function utf8_strtoupper($string){
-  if(UTF8_MBSTRING) return mb_strtoupper($string,'utf-8');
+if(!function_exists('utf8_strtoupper')){
+    /**
+     * This is a unicode aware replacement for strtoupper()
+     *
+     * Uses mb_string extension if available
+     *
+     * @author Leo Feyer <leo@typolight.org>
+     * @see    strtoupper()
+     * @see    utf8_strtoupper()
+     */
+    function utf8_strtoupper($string){
+      if(UTF8_MBSTRING) return mb_strtoupper($string,'utf-8');
 
-  global $UTF8_LOWER_TO_UPPER;
-  return strtr($string,$UTF8_LOWER_TO_UPPER);
+      global $UTF8_LOWER_TO_UPPER;
+      return strtr($string,$UTF8_LOWER_TO_UPPER);
+    }
 }
 
-/**
- * UTF-8 aware alternative to ucfirst
- * Make a string's first character uppercase
- *
- * @author Harry Fuecks
- * @param string
- * @return string with first character as upper case (if applicable)
- */
-function utf8_ucfirst($str){
-  switch ( utf8_strlen($str) ) {
-    case 0:
-        return '';
-    case 1:
-        return utf8_strtoupper($str);
-    default:
-        preg_match('/^(.{1})(.*)$/us', $str, $matches);
-        return utf8_strtoupper($matches[1]).$matches[2];
-  }
+if(!function_exists('utf8_ucfirst')){
+    /**
+     * UTF-8 aware alternative to ucfirst
+     * Make a string's first character uppercase
+     *
+     * @author Harry Fuecks
+     * @param string
+     * @return string with first character as upper case (if applicable)
+     */
+    function utf8_ucfirst($str){
+      switch ( utf8_strlen($str) ) {
+        case 0:
+            return '';
+        case 1:
+            return utf8_strtoupper($str);
+        default:
+            preg_match('/^(.{1})(.*)$/us', $str, $matches);
+            return utf8_strtoupper($matches[1]).$matches[2];
+      }
+    }
 }
 
-/**
- * UTF-8 aware alternative to ucwords
- * Uppercase the first character of each word in a string
- *
- * @author Harry Fuecks
- * @param string
- * @return string with first char of each word uppercase
- * @see http://www.php.net/ucwords
- */
-function utf8_ucwords($str) {
-  // Note: [\x0c\x09\x0b\x0a\x0d\x20] matches;
-  // form feeds, horizontal tabs, vertical tabs, linefeeds and carriage returns
-  // This corresponds to the definition of a "word" defined at http://www.php.net/ucwords
-  $pattern = '/(^|([\x0c\x09\x0b\x0a\x0d\x20]+))([^\x0c\x09\x0b\x0a\x0d\x20]{1})[^\x0c\x09\x0b\x0a\x0d\x20]*/u';
+if(!function_exists('utf8_ucwords')){
+    /**
+     * UTF-8 aware alternative to ucwords
+     * Uppercase the first character of each word in a string
+     *
+     * @author Harry Fuecks
+     * @param string
+     * @return string with first char of each word uppercase
+     * @see http://www.php.net/ucwords
+     */
+    function utf8_ucwords($str) {
+      // Note: [\x0c\x09\x0b\x0a\x0d\x20] matches;
+      // form feeds, horizontal tabs, vertical tabs, linefeeds and carriage returns
+      // This corresponds to the definition of a "word" defined at http://www.php.net/ucwords
+      $pattern = '/(^|([\x0c\x09\x0b\x0a\x0d\x20]+))([^\x0c\x09\x0b\x0a\x0d\x20]{1})[^\x0c\x09\x0b\x0a\x0d\x20]*/u';
 
-  return preg_replace_callback($pattern, 'utf8_ucwords_callback',$str);
-}
+      return preg_replace_callback($pattern, 'utf8_ucwords_callback',$str);
+    }
 
-/**
- * Callback function for preg_replace_callback call in utf8_ucwords
- * You don't need to call this yourself
- *
- * @author Harry Fuecks
- * @param array of matches corresponding to a single word
- * @return string with first char of the word in uppercase
- * @see utf8_ucwords
- * @see utf8_strtoupper
- */
-function utf8_ucwords_callback($matches) {
-  $leadingws = $matches[2];
-  $ucfirst = utf8_strtoupper($matches[3]);
-  $ucword = utf8_substr_replace(ltrim($matches[0]),$ucfirst,0,1);
-  return $leadingws . $ucword;
+    /**
+     * Callback function for preg_replace_callback call in utf8_ucwords
+     * You don't need to call this yourself
+     *
+     * @author Harry Fuecks
+     * @param array of matches corresponding to a single word
+     * @return string with first char of the word in uppercase
+     * @see utf8_ucwords
+     * @see utf8_strtoupper
+     */
+    function utf8_ucwords_callback($matches) {
+      $leadingws = $matches[2];
+      $ucfirst = utf8_strtoupper($matches[3]);
+      $ucword = utf8_substr_replace(ltrim($matches[0]),$ucfirst,0,1);
+      return $leadingws . $ucword;
+    }
 }
 
-/**
- * Replace accented UTF-8 characters by unaccented ASCII-7 equivalents
- *
- * Use the optional parameter to just deaccent lower ($case = -1) or upper ($case = 1)
- * letters. Default is to deaccent both cases ($case = 0)
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- */
-function utf8_deaccent($string,$case=0){
-  if($case <= 0){
-    global $UTF8_LOWER_ACCENTS;
-    $string = strtr($string,$UTF8_LOWER_ACCENTS);
-  }
-  if($case >= 0){
-    global $UTF8_UPPER_ACCENTS;
-    $string = strtr($string,$UTF8_UPPER_ACCENTS);
-  }
-  return $string;
+if(!function_exists('utf8_deaccent')){
+    /**
+     * Replace accented UTF-8 characters by unaccented ASCII-7 equivalents
+     *
+     * Use the optional parameter to just deaccent lower ($case = -1) or upper ($case = 1)
+     * letters. Default is to deaccent both cases ($case = 0)
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     */
+    function utf8_deaccent($string,$case=0){
+        if($case <= 0){
+            global $UTF8_LOWER_ACCENTS;
+            $string = strtr($string,$UTF8_LOWER_ACCENTS);
+        }
+        if($case >= 0){
+            global $UTF8_UPPER_ACCENTS;
+            $string = strtr($string,$UTF8_UPPER_ACCENTS);
+        }
+        return $string;
+    }
 }
 
-/**
- * Romanize a non-latin string
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- */
-function utf8_romanize($string){
-  if(utf8_isASCII($string)) return $string; //nothing to do
+if(!function_exists('utf8_romanize')){
+    /**
+     * Romanize a non-latin string
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     */
+    function utf8_romanize($string){
+        if(utf8_isASCII($string)) return $string; //nothing to do
 
-  global $UTF8_ROMANIZATION;
-  return strtr($string,$UTF8_ROMANIZATION);
+        global $UTF8_ROMANIZATION;
+        return strtr($string,$UTF8_ROMANIZATION);
+    }
 }
 
-/**
- * Removes special characters (nonalphanumeric) from a UTF-8 string
- *
- * This function adds the controlchars 0x00 to 0x19 to the array of
- * stripped chars (they are not included in $UTF8_SPECIAL_CHARS)
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @param  string $string     The UTF8 string to strip of special chars
- * @param  string $repl       Replace special with this string
- * @param  string $additional Additional chars to strip (used in regexp char class)
- */
-function utf8_stripspecials($string,$repl='',$additional=''){
-  global $UTF8_SPECIAL_CHARS;
-  global $UTF8_SPECIAL_CHARS2;
-
-  static $specials = null;
-  if(is_null($specials)){
-#    $specials = preg_quote(unicode_to_utf8($UTF8_SPECIAL_CHARS), '/');
-    $specials = preg_quote($UTF8_SPECIAL_CHARS2, '/');
-  }
+if(!function_exists('utf8_stripspecials')){
+    /**
+     * Removes special characters (nonalphanumeric) from a UTF-8 string
+     *
+     * This function adds the controlchars 0x00 to 0x19 to the array of
+     * stripped chars (they are not included in $UTF8_SPECIAL_CHARS)
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @param  string $string     The UTF8 string to strip of special chars
+     * @param  string $repl       Replace special with this string
+     * @param  string $additional Additional chars to strip (used in regexp char class)
+     */
+    function utf8_stripspecials($string,$repl='',$additional=''){
+        global $UTF8_SPECIAL_CHARS;
+        global $UTF8_SPECIAL_CHARS2;
+
+        static $specials = null;
+        if(is_null($specials)){
+            #$specials = preg_quote(unicode_to_utf8($UTF8_SPECIAL_CHARS), '/');
+            $specials = preg_quote($UTF8_SPECIAL_CHARS2, '/');
+        }
 
-  return preg_replace('/['.$additional.'\x00-\x19'.$specials.']/u',$repl,$string);
+        return preg_replace('/['.$additional.'\x00-\x19'.$specials.']/u',$repl,$string);
+    }
 }
 
-/**
- * This is an Unicode aware replacement for strpos
- *
- * @author Leo Feyer <leo@typolight.org>
- * @see    strpos()
- * @param  string
- * @param  string
- * @param  integer
- * @return integer
- */
-function utf8_strpos($haystack, $needle, $offset=0){
-    $comp = 0;
-    $length = null;
+if(!function_exists('utf8_strpos')){
+    /**
+     * This is an Unicode aware replacement for strpos
+     *
+     * @author Leo Feyer <leo@typolight.org>
+     * @see    strpos()
+     * @param  string
+     * @param  string
+     * @param  integer
+     * @return integer
+     */
+    function utf8_strpos($haystack, $needle, $offset=0){
+        $comp = 0;
+        $length = null;
 
-    while (is_null($length) || $length < $offset) {
-        $pos = strpos($haystack, $needle, $offset + $comp);
+        while (is_null($length) || $length < $offset) {
+            $pos = strpos($haystack, $needle, $offset + $comp);
 
-        if ($pos === false)
-            return false;
+            if ($pos === false)
+                return false;
 
-        $length = utf8_strlen(substr($haystack, 0, $pos));
+            $length = utf8_strlen(substr($haystack, 0, $pos));
 
-        if ($length < $offset)
-            $comp = $pos - $length;
-    }
+            if ($length < $offset)
+                $comp = $pos - $length;
+        }
 
-    return $length;
+        return $length;
+    }
 }
 
+if(!function_exists('utf8_tohtml')){
+    /**
+     * Encodes UTF-8 characters to HTML entities
+     *
+     * @author Tom N Harris <tnharris@whoopdedo.org>
+     * @author <vpribish at shopping dot com>
+     * @link   http://www.php.net/manual/en/function.utf8-decode.php
+     */
+    function utf8_tohtml ($str) {
+        $ret = '';
+        foreach (utf8_to_unicode($str) as $cp) {
+            if ($cp < 0x80)
+                $ret .= chr($cp);
+            elseif ($cp < 0x100)
+                $ret .= "&#$cp;";
+            else
+                $ret .= '&#x'.dechex($cp).';';
+        }
+        return $ret;
+    }
+}
 
-/**
- * Encodes UTF-8 characters to HTML entities
- *
- * @author Tom N Harris <tnharris@whoopdedo.org>
- * @author <vpribish at shopping dot com>
- * @link   http://www.php.net/manual/en/function.utf8-decode.php
- */
-function utf8_tohtml ($str) {
-    $ret = '';
-    foreach (utf8_to_unicode($str) as $cp) {
-        if ($cp < 0x80)
-            $ret .= chr($cp);
-        elseif ($cp < 0x100)
-            $ret .= "&#$cp;";
+if(!function_exists('utf8_unhtml')){
+    /**
+     * Decodes HTML entities to UTF-8 characters
+     *
+     * Convert any &#..; entity to a codepoint,
+     * The entities flag defaults to only decoding numeric entities.
+     * Pass HTML_ENTITIES and named entities, including &amp; &lt; etc.
+     * are handled as well. Avoids the problem that would occur if you
+     * had to decode "&amp;#38;&#38;amp;#38;"
+     *
+     * unhtmlspecialchars(utf8_unhtml($s)) -> "&#38;&#38;"
+     * utf8_unhtml(unhtmlspecialchars($s)) -> "&&amp#38;"
+     * what it should be                   -> "&#38;&amp#38;"
+     *
+     * @author Tom N Harris <tnharris@whoopdedo.org>
+     * @param  string  $str      UTF-8 encoded string
+     * @param  boolean $entities Flag controlling decoding of named entities.
+     * @return UTF-8 encoded string with numeric (and named) entities replaced.
+     */
+    function utf8_unhtml($str, $entities=null) {
+        static $decoder = null;
+        if (is_null($decoder))
+            $decoder = new utf8_entity_decoder();
+        if (is_null($entities))
+            return preg_replace_callback('/(&#([Xx])?([0-9A-Za-z]+);)/m',
+                                         'utf8_decode_numeric', $str);
         else
-            $ret .= '&#x'.dechex($cp).';';
+            return preg_replace_callback('/&(#)?([Xx])?([0-9A-Za-z]+);/m',
+                                         array(&$decoder, 'decode'), $str);
     }
-    return $ret;
 }
 
-/**
- * Decodes HTML entities to UTF-8 characters
- *
- * Convert any &#..; entity to a codepoint,
- * The entities flag defaults to only decoding numeric entities.
- * Pass HTML_ENTITIES and named entities, including &amp; &lt; etc.
- * are handled as well. Avoids the problem that would occur if you
- * had to decode "&amp;#38;&#38;amp;#38;"
- *
- * unhtmlspecialchars(utf8_unhtml($s)) -> "&#38;&#38;"
- * utf8_unhtml(unhtmlspecialchars($s)) -> "&&amp#38;"
- * what it should be                   -> "&#38;&amp#38;"
- *
- * @author Tom N Harris <tnharris@whoopdedo.org>
- * @param  string  $str      UTF-8 encoded string
- * @param  boolean $entities Flag controlling decoding of named entities.
- * @return UTF-8 encoded string with numeric (and named) entities replaced.
- */
-function utf8_unhtml($str, $entities=null) {
-    static $decoder = null;
-    if (is_null($decoder))
-      $decoder = new utf8_entity_decoder();
-    if (is_null($entities))
-        return preg_replace_callback('/(&#([Xx])?([0-9A-Za-z]+);)/m',
-                                     'utf8_decode_numeric', $str);
-    else
-        return preg_replace_callback('/&(#)?([Xx])?([0-9A-Za-z]+);/m',
-                                     array(&$decoder, 'decode'), $str);
-}
-function utf8_decode_numeric($ent) {
-    switch ($ent[2]) {
-      case 'X':
-      case 'x':
-          $cp = hexdec($ent[3]);
-          break;
-      default:
-          $cp = intval($ent[3]);
-          break;
+if(!function_exists('utf8_decode_numeric')){
+    function utf8_decode_numeric($ent) {
+        switch ($ent[2]) {
+          case 'X':
+          case 'x':
+              $cp = hexdec($ent[3]);
+              break;
+          default:
+              $cp = intval($ent[3]);
+              break;
+        }
+        return unicode_to_utf8(array($cp));
     }
-    return unicode_to_utf8(array($cp));
 }
-class utf8_entity_decoder {
-    var $table;
-    function utf8_entity_decoder() {
-        $table = get_html_translation_table(HTML_ENTITIES);
-        $table = array_flip($table);
-        $this->table = array_map(array(&$this,'makeutf8'), $table);
-    }
-    function makeutf8($c) {
-        return unicode_to_utf8(array(ord($c)));
-    }
-    function decode($ent) {
-        if ($ent[1] == '#') {
-            return utf8_decode_numeric($ent);
-        } elseif (array_key_exists($ent[0],$this->table)) {
-            return $this->table[$ent[0]];
-        } else {
-            return $ent[0];
+
+if(!class_exists('utf8_entity_decoder')){
+    class utf8_entity_decoder {
+        var $table;
+        function utf8_entity_decoder() {
+            $table = get_html_translation_table(HTML_ENTITIES);
+            $table = array_flip($table);
+            $this->table = array_map(array(&$this,'makeutf8'), $table);
+        }
+        function makeutf8($c) {
+            return unicode_to_utf8(array(ord($c)));
+        }
+        function decode($ent) {
+            if ($ent[1] == '#') {
+                return utf8_decode_numeric($ent);
+            } elseif (array_key_exists($ent[0],$this->table)) {
+                return $this->table[$ent[0]];
+            } else {
+                return $ent[0];
+            }
         }
     }
 }
 
-/**
- * Takes an UTF-8 string and returns an array of ints representing the
- * Unicode characters. Astral planes are supported ie. the ints in the
- * output can be > 0xFFFF. Occurrances of the BOM are ignored. Surrogates
- * are not allowed.
- *
- * If $strict is set to true the function returns false if the input
- * string isn't a valid UTF-8 octet sequence and raises a PHP error at
- * level E_USER_WARNING
- *
- * Note: this function has been modified slightly in this library to
- * trigger errors on encountering bad bytes
- *
- * @author <hsivonen@iki.fi>
- * @author Harry Fuecks <hfuecks@gmail.com>
- * @param  string  UTF-8 encoded string
- * @param  boolean Check for invalid sequences?
- * @return mixed array of unicode code points or false if UTF-8 invalid
- * @see    unicode_to_utf8
- * @link   http://hsivonen.iki.fi/php-utf8/
- * @link   http://sourceforge.net/projects/phputf8/
- */
-function utf8_to_unicode($str,$strict=false) {
-    $mState = 0;     // cached expected number of octets after the current octet
-                     // until the beginning of the next UTF8 character sequence
-    $mUcs4  = 0;     // cached Unicode character
-    $mBytes = 1;     // cached expected number of octets in the current sequence
-
-    $out = array();
-
-    $len = strlen($str);
-
-    for($i = 0; $i < $len; $i++) {
-
-        $in = ord($str{$i});
-
-        if ( $mState == 0) {
-
-            // When mState is zero we expect either a US-ASCII character or a
-            // multi-octet sequence.
-            if (0 == (0x80 & ($in))) {
-                // US-ASCII, pass straight through.
-                $out[] = $in;
-                $mBytes = 1;
-
-            } else if (0xC0 == (0xE0 & ($in))) {
-                // First octet of 2 octet sequence
-                $mUcs4 = ($in);
-                $mUcs4 = ($mUcs4 & 0x1F) << 6;
-                $mState = 1;
-                $mBytes = 2;
-
-            } else if (0xE0 == (0xF0 & ($in))) {
-                // First octet of 3 octet sequence
-                $mUcs4 = ($in);
-                $mUcs4 = ($mUcs4 & 0x0F) << 12;
-                $mState = 2;
-                $mBytes = 3;
-
-            } else if (0xF0 == (0xF8 & ($in))) {
-                // First octet of 4 octet sequence
-                $mUcs4 = ($in);
-                $mUcs4 = ($mUcs4 & 0x07) << 18;
-                $mState = 3;
-                $mBytes = 4;
-
-            } else if (0xF8 == (0xFC & ($in))) {
-                /* First octet of 5 octet sequence.
-                 *
-                 * This is illegal because the encoded codepoint must be either
-                 * (a) not the shortest form or
-                 * (b) outside the Unicode range of 0-0x10FFFF.
-                 * Rather than trying to resynchronize, we will carry on until the end
-                 * of the sequence and let the later error handling code catch it.
-                 */
-                $mUcs4 = ($in);
-                $mUcs4 = ($mUcs4 & 0x03) << 24;
-                $mState = 4;
-                $mBytes = 5;
-
-            } else if (0xFC == (0xFE & ($in))) {
-                // First octet of 6 octet sequence, see comments for 5 octet sequence.
-                $mUcs4 = ($in);
-                $mUcs4 = ($mUcs4 & 1) << 30;
-                $mState = 5;
-                $mBytes = 6;
+if(!function_exists('utf8_to_unicode')){
+    /**
+     * Takes an UTF-8 string and returns an array of ints representing the
+     * Unicode characters. Astral planes are supported ie. the ints in the
+     * output can be > 0xFFFF. Occurrances of the BOM are ignored. Surrogates
+     * are not allowed.
+     *
+     * If $strict is set to true the function returns false if the input
+     * string isn't a valid UTF-8 octet sequence and raises a PHP error at
+     * level E_USER_WARNING
+     *
+     * Note: this function has been modified slightly in this library to
+     * trigger errors on encountering bad bytes
+     *
+     * @author <hsivonen@iki.fi>
+     * @author Harry Fuecks <hfuecks@gmail.com>
+     * @param  string  UTF-8 encoded string
+     * @param  boolean Check for invalid sequences?
+     * @return mixed array of unicode code points or false if UTF-8 invalid
+     * @see    unicode_to_utf8
+     * @link   http://hsivonen.iki.fi/php-utf8/
+     * @link   http://sourceforge.net/projects/phputf8/
+     */
+    function utf8_to_unicode($str,$strict=false) {
+        $mState = 0;     // cached expected number of octets after the current octet
+                         // until the beginning of the next UTF8 character sequence
+        $mUcs4  = 0;     // cached Unicode character
+        $mBytes = 1;     // cached expected number of octets in the current sequence
 
-            } elseif($strict) {
-                /* Current octet is neither in the US-ASCII range nor a legal first
-                 * octet of a multi-octet sequence.
-                 */
-                trigger_error(
-                        'utf8_to_unicode: Illegal sequence identifier '.
-                            'in UTF-8 at byte '.$i,
-                        E_USER_WARNING
-                    );
-                return false;
+        $out = array();
 
-            }
+        $len = strlen($str);
 
-        } else {
+        for($i = 0; $i < $len; $i++) {
+
+            $in = ord($str{$i});
+
+            if ( $mState == 0) {
+
+                // When mState is zero we expect either a US-ASCII character or a
+                // multi-octet sequence.
+                if (0 == (0x80 & ($in))) {
+                    // US-ASCII, pass straight through.
+                    $out[] = $in;
+                    $mBytes = 1;
+
+                } else if (0xC0 == (0xE0 & ($in))) {
+                    // First octet of 2 octet sequence
+                    $mUcs4 = ($in);
+                    $mUcs4 = ($mUcs4 & 0x1F) << 6;
+                    $mState = 1;
+                    $mBytes = 2;
+
+                } else if (0xE0 == (0xF0 & ($in))) {
+                    // First octet of 3 octet sequence
+                    $mUcs4 = ($in);
+                    $mUcs4 = ($mUcs4 & 0x0F) << 12;
+                    $mState = 2;
+                    $mBytes = 3;
+
+                } else if (0xF0 == (0xF8 & ($in))) {
+                    // First octet of 4 octet sequence
+                    $mUcs4 = ($in);
+                    $mUcs4 = ($mUcs4 & 0x07) << 18;
+                    $mState = 3;
+                    $mBytes = 4;
+
+                } else if (0xF8 == (0xFC & ($in))) {
+                    /* First octet of 5 octet sequence.
+                     *
+                     * This is illegal because the encoded codepoint must be either
+                     * (a) not the shortest form or
+                     * (b) outside the Unicode range of 0-0x10FFFF.
+                     * Rather than trying to resynchronize, we will carry on until the end
+                     * of the sequence and let the later error handling code catch it.
+                     */
+                    $mUcs4 = ($in);
+                    $mUcs4 = ($mUcs4 & 0x03) << 24;
+                    $mState = 4;
+                    $mBytes = 5;
+
+                } else if (0xFC == (0xFE & ($in))) {
+                    // First octet of 6 octet sequence, see comments for 5 octet sequence.
+                    $mUcs4 = ($in);
+                    $mUcs4 = ($mUcs4 & 1) << 30;
+                    $mState = 5;
+                    $mBytes = 6;
+
+                } elseif($strict) {
+                    /* Current octet is neither in the US-ASCII range nor a legal first
+                     * octet of a multi-octet sequence.
+                     */
+                    trigger_error(
+                            'utf8_to_unicode: Illegal sequence identifier '.
+                                'in UTF-8 at byte '.$i,
+                            E_USER_WARNING
+                        );
+                    return false;
 
-            // When mState is non-zero, we expect a continuation of the multi-octet
-            // sequence
-            if (0x80 == (0xC0 & ($in))) {
+                }
+
+            } else {
 
-                // Legal continuation.
-                $shift = ($mState - 1) * 6;
-                $tmp = $in;
-                $tmp = ($tmp & 0x0000003F) << $shift;
-                $mUcs4 |= $tmp;
+                // When mState is non-zero, we expect a continuation of the multi-octet
+                // sequence
+                if (0x80 == (0xC0 & ($in))) {
 
-                /**
-                 * End of the multi-octet sequence. mUcs4 now contains the final
-                 * Unicode codepoint to be output
-                 */
-                if (0 == --$mState) {
+                    // Legal continuation.
+                    $shift = ($mState - 1) * 6;
+                    $tmp = $in;
+                    $tmp = ($tmp & 0x0000003F) << $shift;
+                    $mUcs4 |= $tmp;
 
-                    /*
-                     * Check for illegal sequences and codepoints.
+                    /**
+                     * End of the multi-octet sequence. mUcs4 now contains the final
+                     * Unicode codepoint to be output
                      */
-                    // From Unicode 3.1, non-shortest form is illegal
-                    if (((2 == $mBytes) && ($mUcs4 < 0x0080)) ||
-                        ((3 == $mBytes) && ($mUcs4 < 0x0800)) ||
-                        ((4 == $mBytes) && ($mUcs4 < 0x10000)) ||
-                        (4 < $mBytes) ||
-                        // From Unicode 3.2, surrogate characters are illegal
-                        (($mUcs4 & 0xFFFFF800) == 0xD800) ||
-                        // Codepoints outside the Unicode range are illegal
-                        ($mUcs4 > 0x10FFFF)) {
-
-                        if($strict){
-                            trigger_error(
-                                    'utf8_to_unicode: Illegal sequence or codepoint '.
-                                        'in UTF-8 at byte '.$i,
-                                    E_USER_WARNING
-                                );
-
-                            return false;
+                    if (0 == --$mState) {
+
+                        /*
+                         * Check for illegal sequences and codepoints.
+                         */
+                        // From Unicode 3.1, non-shortest form is illegal
+                        if (((2 == $mBytes) && ($mUcs4 < 0x0080)) ||
+                            ((3 == $mBytes) && ($mUcs4 < 0x0800)) ||
+                            ((4 == $mBytes) && ($mUcs4 < 0x10000)) ||
+                            (4 < $mBytes) ||
+                            // From Unicode 3.2, surrogate characters are illegal
+                            (($mUcs4 & 0xFFFFF800) == 0xD800) ||
+                            // Codepoints outside the Unicode range are illegal
+                            ($mUcs4 > 0x10FFFF)) {
+
+                            if($strict){
+                                trigger_error(
+                                        'utf8_to_unicode: Illegal sequence or codepoint '.
+                                            'in UTF-8 at byte '.$i,
+                                        E_USER_WARNING
+                                    );
+
+                                return false;
+                            }
+
                         }
 
-                    }
+                        if (0xFEFF != $mUcs4) {
+                            // BOM is legal but we don't want to output it
+                            $out[] = $mUcs4;
+                        }
 
-                    if (0xFEFF != $mUcs4) {
-                        // BOM is legal but we don't want to output it
-                        $out[] = $mUcs4;
+                        //initialize UTF8 cache
+                        $mState = 0;
+                        $mUcs4  = 0;
+                        $mBytes = 1;
                     }
 
-                    //initialize UTF8 cache
-                    $mState = 0;
-                    $mUcs4  = 0;
-                    $mBytes = 1;
-                }
-
-            } elseif($strict) {
-                /**
-                 *((0xC0 & (*in) != 0x80) && (mState != 0))
-                 * Incomplete multi-octet sequence.
-                 */
-                trigger_error(
-                        'utf8_to_unicode: Incomplete multi-octet '.
-                        '   sequence in UTF-8 at byte '.$i,
-                        E_USER_WARNING
-                    );
+                } elseif($strict) {
+                    /**
+                     *((0xC0 & (*in) != 0x80) && (mState != 0))
+                     * Incomplete multi-octet sequence.
+                     */
+                    trigger_error(
+                            'utf8_to_unicode: Incomplete multi-octet '.
+                            '   sequence in UTF-8 at byte '.$i,
+                            E_USER_WARNING
+                        );
 
-                return false;
+                    return false;
+                }
             }
         }
+        return $out;
     }
-    return $out;
 }
 
-/**
- * Takes an array of ints representing the Unicode characters and returns
- * a UTF-8 string. Astral planes are supported ie. the ints in the
- * input can be > 0xFFFF. Occurrances of the BOM are ignored. Surrogates
- * are not allowed.
- *
- * If $strict is set to true the function returns false if the input
- * array contains ints that represent surrogates or are outside the
- * Unicode range and raises a PHP error at level E_USER_WARNING
- *
- * Note: this function has been modified slightly in this library to use
- * output buffering to concatenate the UTF-8 string (faster) as well as
- * reference the array by it's keys
- *
- * @param  array of unicode code points representing a string
- * @param  boolean Check for invalid sequences?
- * @return mixed UTF-8 string or false if array contains invalid code points
- * @author <hsivonen@iki.fi>
- * @author Harry Fuecks <hfuecks@gmail.com>
- * @see    utf8_to_unicode
- * @link   http://hsivonen.iki.fi/php-utf8/
- * @link   http://sourceforge.net/projects/phputf8/
- */
-function unicode_to_utf8($arr,$strict=false) {
-    if (!is_array($arr)) return '';
-    ob_start();
+if(!function_exists('unicode_to_utf8')){
+    /**
+     * Takes an array of ints representing the Unicode characters and returns
+     * a UTF-8 string. Astral planes are supported ie. the ints in the
+     * input can be > 0xFFFF. Occurrances of the BOM are ignored. Surrogates
+     * are not allowed.
+     *
+     * If $strict is set to true the function returns false if the input
+     * array contains ints that represent surrogates or are outside the
+     * Unicode range and raises a PHP error at level E_USER_WARNING
+     *
+     * Note: this function has been modified slightly in this library to use
+     * output buffering to concatenate the UTF-8 string (faster) as well as
+     * reference the array by it's keys
+     *
+     * @param  array of unicode code points representing a string
+     * @param  boolean Check for invalid sequences?
+     * @return mixed UTF-8 string or false if array contains invalid code points
+     * @author <hsivonen@iki.fi>
+     * @author Harry Fuecks <hfuecks@gmail.com>
+     * @see    utf8_to_unicode
+     * @link   http://hsivonen.iki.fi/php-utf8/
+     * @link   http://sourceforge.net/projects/phputf8/
+     */
+    function unicode_to_utf8($arr,$strict=false) {
+        if (!is_array($arr)) return '';
+        ob_start();
 
-    foreach (array_keys($arr) as $k) {
+        foreach (array_keys($arr) as $k) {
 
-        # ASCII range (including control chars)
-        if ( ($arr[$k] >= 0) && ($arr[$k] <= 0x007f) ) {
+            # ASCII range (including control chars)
+            if ( ($arr[$k] >= 0) && ($arr[$k] <= 0x007f) ) {
 
-            echo chr($arr[$k]);
+                echo chr($arr[$k]);
 
-        # 2 byte sequence
-        } else if ($arr[$k] <= 0x07ff) {
+            # 2 byte sequence
+            } else if ($arr[$k] <= 0x07ff) {
 
-            echo chr(0xc0 | ($arr[$k] >> 6));
-            echo chr(0x80 | ($arr[$k] & 0x003f));
+                echo chr(0xc0 | ($arr[$k] >> 6));
+                echo chr(0x80 | ($arr[$k] & 0x003f));
 
-        # Byte order mark (skip)
-        } else if($arr[$k] == 0xFEFF) {
+            # Byte order mark (skip)
+            } else if($arr[$k] == 0xFEFF) {
 
-            // nop -- zap the BOM
+                // nop -- zap the BOM
 
-        # Test for illegal surrogates
-        } else if ($arr[$k] >= 0xD800 && $arr[$k] <= 0xDFFF) {
+            # Test for illegal surrogates
+            } else if ($arr[$k] >= 0xD800 && $arr[$k] <= 0xDFFF) {
 
-            // found a surrogate
-            if($strict){
-                trigger_error(
-                    'unicode_to_utf8: Illegal surrogate '.
-                        'at index: '.$k.', value: '.$arr[$k],
-                    E_USER_WARNING
-                    );
-                return false;
-            }
+                // found a surrogate
+                if($strict){
+                    trigger_error(
+                        'unicode_to_utf8: Illegal surrogate '.
+                            'at index: '.$k.', value: '.$arr[$k],
+                        E_USER_WARNING
+                        );
+                    return false;
+                }
 
-        # 3 byte sequence
-        } else if ($arr[$k] <= 0xffff) {
+            # 3 byte sequence
+            } else if ($arr[$k] <= 0xffff) {
 
-            echo chr(0xe0 | ($arr[$k] >> 12));
-            echo chr(0x80 | (($arr[$k] >> 6) & 0x003f));
-            echo chr(0x80 | ($arr[$k] & 0x003f));
+                echo chr(0xe0 | ($arr[$k] >> 12));
+                echo chr(0x80 | (($arr[$k] >> 6) & 0x003f));
+                echo chr(0x80 | ($arr[$k] & 0x003f));
 
-        # 4 byte sequence
-        } else if ($arr[$k] <= 0x10ffff) {
+            # 4 byte sequence
+            } else if ($arr[$k] <= 0x10ffff) {
 
-            echo chr(0xf0 | ($arr[$k] >> 18));
-            echo chr(0x80 | (($arr[$k] >> 12) & 0x3f));
-            echo chr(0x80 | (($arr[$k] >> 6) & 0x3f));
-            echo chr(0x80 | ($arr[$k] & 0x3f));
+                echo chr(0xf0 | ($arr[$k] >> 18));
+                echo chr(0x80 | (($arr[$k] >> 12) & 0x3f));
+                echo chr(0x80 | (($arr[$k] >> 6) & 0x3f));
+                echo chr(0x80 | ($arr[$k] & 0x3f));
 
-        } elseif($strict) {
+            } elseif($strict) {
 
-            trigger_error(
-                'unicode_to_utf8: Codepoint out of Unicode range '.
-                    'at index: '.$k.', value: '.$arr[$k],
-                E_USER_WARNING
-                );
+                trigger_error(
+                    'unicode_to_utf8: Codepoint out of Unicode range '.
+                        'at index: '.$k.', value: '.$arr[$k],
+                    E_USER_WARNING
+                    );
 
-            // out of range
-            return false;
+                // out of range
+                return false;
+            }
         }
-    }
 
-    $result = ob_get_contents();
-    ob_end_clean();
-    return $result;
+        $result = ob_get_contents();
+        ob_end_clean();
+        return $result;
+    }
 }
 
-/**
- * UTF-8 to UTF-16BE conversion.
- *
- * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
- */
-function utf8_to_utf16be(&$str, $bom = false) {
-  $out = $bom ? "\xFE\xFF" : '';
-  if(UTF8_MBSTRING) return $out.mb_convert_encoding($str,'UTF-16BE','UTF-8');
+if(!function_exists('utf8_to_utf16be')){
+    /**
+     * UTF-8 to UTF-16BE conversion.
+     *
+     * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
+     */
+    function utf8_to_utf16be(&$str, $bom = false) {
+        $out = $bom ? "\xFE\xFF" : '';
+        if(UTF8_MBSTRING) return $out.mb_convert_encoding($str,'UTF-16BE','UTF-8');
 
-  $uni = utf8_to_unicode($str);
-  foreach($uni as $cp){
-    $out .= pack('n',$cp);
-  }
-  return $out;
+        $uni = utf8_to_unicode($str);
+        foreach($uni as $cp){
+            $out .= pack('n',$cp);
+        }
+        return $out;
+    }
 }
 
-/**
- * UTF-8 to UTF-16BE conversion.
- *
- * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
- */
-function utf16be_to_utf8(&$str) {
-  $uni = unpack('n*',$str);
-  return unicode_to_utf8($uni);
+if(!function_exists('utf16be_to_utf8')){
+    /**
+     * UTF-8 to UTF-16BE conversion.
+     *
+     * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
+     */
+    function utf16be_to_utf8(&$str) {
+        $uni = unpack('n*',$str);
+        return unicode_to_utf8($uni);
+    }
 }
 
-/**
- * Replace bad bytes with an alternative character
- *
- * ASCII character is recommended for replacement char
- *
- * PCRE Pattern to locate bad bytes in a UTF-8 string
- * Comes from W3 FAQ: Multilingual Forms
- * Note: modified to include full ASCII range including control chars
- *
- * @author Harry Fuecks <hfuecks@gmail.com>
- * @see http://www.w3.org/International/questions/qa-forms-utf-8
- * @param string to search
- * @param string to replace bad bytes with (defaults to '?') - use ASCII
- * @return string
- */
-function utf8_bad_replace($str, $replace = '') {
-    $UTF8_BAD =
-     '([\x00-\x7F]'.                          # ASCII (including control chars)
-     '|[\xC2-\xDF][\x80-\xBF]'.               # non-overlong 2-byte
-     '|\xE0[\xA0-\xBF][\x80-\xBF]'.           # excluding overlongs
-     '|[\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}'.    # straight 3-byte
-     '|\xED[\x80-\x9F][\x80-\xBF]'.           # excluding surrogates
-     '|\xF0[\x90-\xBF][\x80-\xBF]{2}'.        # planes 1-3
-     '|[\xF1-\xF3][\x80-\xBF]{3}'.            # planes 4-15
-     '|\xF4[\x80-\x8F][\x80-\xBF]{2}'.        # plane 16
-     '|(.{1}))';                              # invalid byte
-    ob_start();
-    while (preg_match('/'.$UTF8_BAD.'/S', $str, $matches)) {
-        if ( !isset($matches[2])) {
-            echo $matches[0];
-        } else {
-            echo $replace;
+if(!function_exists('utf8_bad_replace')){
+    /**
+     * Replace bad bytes with an alternative character
+     *
+     * ASCII character is recommended for replacement char
+     *
+     * PCRE Pattern to locate bad bytes in a UTF-8 string
+     * Comes from W3 FAQ: Multilingual Forms
+     * Note: modified to include full ASCII range including control chars
+     *
+     * @author Harry Fuecks <hfuecks@gmail.com>
+     * @see http://www.w3.org/International/questions/qa-forms-utf-8
+     * @param string to search
+     * @param string to replace bad bytes with (defaults to '?') - use ASCII
+     * @return string
+     */
+    function utf8_bad_replace($str, $replace = '') {
+        $UTF8_BAD =
+         '([\x00-\x7F]'.                          # ASCII (including control chars)
+         '|[\xC2-\xDF][\x80-\xBF]'.               # non-overlong 2-byte
+         '|\xE0[\xA0-\xBF][\x80-\xBF]'.           # excluding overlongs
+         '|[\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}'.    # straight 3-byte
+         '|\xED[\x80-\x9F][\x80-\xBF]'.           # excluding surrogates
+         '|\xF0[\x90-\xBF][\x80-\xBF]{2}'.        # planes 1-3
+         '|[\xF1-\xF3][\x80-\xBF]{3}'.            # planes 4-15
+         '|\xF4[\x80-\x8F][\x80-\xBF]{2}'.        # plane 16
+         '|(.{1}))';                              # invalid byte
+        ob_start();
+        while (preg_match('/'.$UTF8_BAD.'/S', $str, $matches)) {
+            if ( !isset($matches[2])) {
+                echo $matches[0];
+            } else {
+                echo $replace;
+            }
+            $str = substr($str,strlen($matches[0]));
         }
-        $str = substr($str,strlen($matches[0]));
+        $result = ob_get_contents();
+        ob_end_clean();
+        return $result;
     }
-    $result = ob_get_contents();
-    ob_end_clean();
-    return $result;
 }
 
-/**
- * adjust a byte index into a utf8 string to a utf8 character boundary
- *
- * @param $str   string   utf8 character string
- * @param $i     int      byte index into $str
- * @param $next  bool     direction to search for boundary,
- *                           false = up (current character)
- *                           true = down (next character)
- *
- * @return int            byte index into $str now pointing to a utf8 character boundary
- *
- * @author       chris smith <chris@jalakai.co.uk>
- */
-function utf8_correctIdx(&$str,$i,$next=false) {
+if(!function_exists('utf8_correctIdx')){
+    /**
+     * adjust a byte index into a utf8 string to a utf8 character boundary
+     *
+     * @param $str   string   utf8 character string
+     * @param $i     int      byte index into $str
+     * @param $next  bool     direction to search for boundary,
+     *                           false = up (current character)
+     *                           true = down (next character)
+     *
+     * @return int            byte index into $str now pointing to a utf8 character boundary
+     *
+     * @author       chris smith <chris@jalakai.co.uk>
+     */
+    function utf8_correctIdx(&$str,$i,$next=false) {
 
-  if ($i <= 0) return 0;
+        if ($i <= 0) return 0;
 
-  $limit = strlen($str);
-  if ($i>=$limit) return $limit;
+        $limit = strlen($str);
+        if ($i>=$limit) return $limit;
 
-  if ($next) {
-    while (($i<$limit) && ((ord($str[$i]) & 0xC0) == 0x80)) $i++;
-  } else {
-    while ($i && ((ord($str[$i]) & 0xC0) == 0x80)) $i--;
-  }
+        if ($next) {
+            while (($i<$limit) && ((ord($str[$i]) & 0xC0) == 0x80)) $i++;
+        } else {
+            while ($i && ((ord($str[$i]) & 0xC0) == 0x80)) $i--;
+        }
 
-  return $i;
+        return $i;
+    }
 }
 
 // only needed if no mb_string available
@@ -909,7 +967,7 @@ if(!UTF8_MBSTRING){
    * @author Andreas Gohr <andi@splitbrain.org>
    */
   global $UTF8_LOWER_TO_UPPER;
-  $UTF8_LOWER_TO_UPPER = array(
+  if(empty($UTF8_LOWER_TO_UPPER)) $UTF8_LOWER_TO_UPPER = array(
     "ｚ"=>"Ｚ","ｙ"=>"Ｙ","ｘ"=>"Ｘ","ｗ"=>"Ｗ","ｖ"=>"Ｖ","ｕ"=>"Ｕ","ｔ"=>"Ｔ","ｓ"=>"Ｓ","ｒ"=>"Ｒ","ｑ"=>"Ｑ",
     "ｐ"=>"Ｐ","ｏ"=>"Ｏ","ｎ"=>"Ｎ","ｍ"=>"Ｍ","ｌ"=>"Ｌ","ｋ"=>"Ｋ","ｊ"=>"Ｊ","ｉ"=>"Ｉ","ｈ"=>"Ｈ","ｇ"=>"Ｇ",
     "ｆ"=>"Ｆ","ｅ"=>"Ｅ","ｄ"=>"Ｄ","ｃ"=>"Ｃ","ｂ"=>"Ｂ","ａ"=>"Ａ","ῳ"=>"ῼ","ῥ"=>"Ῥ","ῡ"=>"Ῡ","ῑ"=>"Ῑ",
@@ -988,7 +1046,7 @@ if(!UTF8_MBSTRING){
    * @author Andreas Gohr <andi@splitbrain.org>
    */
   global $UTF8_UPPER_TO_LOWER;
-  $UTF8_UPPER_TO_LOWER = array (
+  if(empty($UTF8_UPPER_TO_LOWER)) $UTF8_UPPER_TO_LOWER = array (
     "Ｚ"=>"ｚ","Ｙ"=>"ｙ","Ｘ"=>"ｘ","Ｗ"=>"ｗ","Ｖ"=>"ｖ","Ｕ"=>"ｕ","Ｔ"=>"ｔ","Ｓ"=>"ｓ","Ｒ"=>"ｒ","Ｑ"=>"ｑ",
     "Ｐ"=>"ｐ","Ｏ"=>"ｏ","Ｎ"=>"ｎ","Ｍ"=>"ｍ","Ｌ"=>"ｌ","Ｋ"=>"ｋ","Ｊ"=>"ｊ","Ｉ"=>"ｉ","Ｈ"=>"ｈ","Ｇ"=>"ｇ",
     "Ｆ"=>"ｆ","Ｅ"=>"ｅ","Ｄ"=>"ｄ","Ｃ"=>"ｃ","Ｂ"=>"ｂ","Ａ"=>"ａ","ῼ"=>"ῳ","Ῥ"=>"ῥ","Ῡ"=>"ῡ","Ῑ"=>"ῑ",
@@ -1069,7 +1127,7 @@ if(!UTF8_MBSTRING){
  * @see    utf8_deaccent()
  */
 global $UTF8_LOWER_ACCENTS;
-$UTF8_LOWER_ACCENTS = array(
+if(empty($UTF8_LOWER_ACCENTS)) $UTF8_LOWER_ACCENTS = array(
   'à' => 'a', 'ô' => 'o', 'ď' => 'd', 'ḟ' => 'f', 'ë' => 'e', 'š' => 's', 'ơ' => 'o',
   'ß' => 'ss', 'ă' => 'a', 'ř' => 'r', 'ț' => 't', 'ň' => 'n', 'ā' => 'a', 'ķ' => 'k',
   'ŝ' => 's', 'ỳ' => 'y', 'ņ' => 'n', 'ĺ' => 'l', 'ħ' => 'h', 'ṗ' => 'p', 'ó' => 'o',
@@ -1097,7 +1155,7 @@ $UTF8_LOWER_ACCENTS = array(
  * @see    utf8_deaccent()
  */
 global $UTF8_UPPER_ACCENTS;
-$UTF8_UPPER_ACCENTS = array(
+if(empty($UTF8_UPPER_ACCENTS)) $UTF8_UPPER_ACCENTS = array(
   'À' => 'A', 'Ô' => 'O', 'Ď' => 'D', 'Ḟ' => 'F', 'Ë' => 'E', 'Š' => 'S', 'Ơ' => 'O',
   'Ă' => 'A', 'Ř' => 'R', 'Ț' => 'T', 'Ň' => 'N', 'Ā' => 'A', 'Ķ' => 'K',
   'Ŝ' => 'S', 'Ỳ' => 'Y', 'Ņ' => 'N', 'Ĺ' => 'L', 'Ħ' => 'H', 'Ṗ' => 'P', 'Ó' => 'O',
@@ -1130,7 +1188,7 @@ $UTF8_UPPER_ACCENTS = array(
  * @see    utf8_stripspecials()
  */
 global $UTF8_SPECIAL_CHARS;
-$UTF8_SPECIAL_CHARS = array(
+if(empty($UTF8_SPECIAL_CHARS)) $UTF8_SPECIAL_CHARS = array(
   0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f, 0x0020, 0x0021, 0x0022, 0x0023,
   0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029,         0x002b, 0x002c,
           0x002f,         0x003b, 0x003c, 0x003d, 0x003e, 0x003f, 0x0040, 0x005b,
@@ -1199,7 +1257,7 @@ $UTF8_SPECIAL_CHARS = array(
 
 // utf8 version of above data
 global $UTF8_SPECIAL_CHARS2;
-$UTF8_SPECIAL_CHARS2 =
+if(empty($UTF8_SPECIAL_CHARS2)) $UTF8_SPECIAL_CHARS2 =
     "\x1A".' !"#$%&\'()+,/;<=>?@[\]^`{|}~€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“”•�'.
     '�—˜™š›œžŸ ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½�'.
     '�¿×÷ˇ˘˙˚˛˜˝̣̀́̃̉΄΅·ϖְֱֲֳִֵֶַָֹֻּֽ־ֿ�'.
@@ -1245,7 +1303,7 @@ $UTF8_SPECIAL_CHARS2 =
  * @author Denis Scheither <amorphis@uni-bremen.de>
  */
 global $UTF8_ROMANIZATION;
-$UTF8_ROMANIZATION = array(
+if(empty($UTF8_ROMANIZATION)) $UTF8_ROMANIZATION = array(
   // scandinavian - differs from what we do in deaccent
   'å'=>'a','Å'=>'A','ä'=>'a','Ä'=>'A','ö'=>'o','Ö'=>'O',