uint8_t utf8Ascii(uint8_t ascii) {
  static uint8_t cPrev;
  uint8_t c = '\0';

  if (ascii < 0x7f)   // Standard ASCII-set 0..0x7F, no conversion
  {
    cPrev = '\0';
    c = ascii;
  }
  else
  {
    switch (cPrev)  // Conversion depending on preceding UTF8-character
    {
    case 0xC2: c = ascii;  break;
    case 0xC3: c = ascii | 0xC0;  break;
    case 0x82: if (ascii==0xAC) c = 0x80; // Euro symbol special case
    }
    cPrev = ascii;   // save last char
  }

  return(c);
}


void utf8Ascii(char* s) {
  uint8_t c, k = 0;
  char *cp = s;

  while (*s != '\0')
  {
    c = utf8Ascii(*s++);
    if (c != '\0')
      *cp++ = c;
  }
  *cp = '\0';   // terminate the new string
}


char* string2char(String command){
    if(command.length()!=0){
        char *p = const_cast<char*>(command.c_str());
        return p;
    }
}


// constant char* to char*
char* cchar2char(String data){
  char* out = new char[data.length()+1];
  strcpy(out, data.c_str());
  return out;
}


char * stringReplace(char *search, char *replace, char *string) {
	char *tempString, *searchStart;
	int len=0;

	searchStart = strstr(string, search);
	if(searchStart == NULL) {
		return string;
	}

	tempString = (char*) malloc(strlen(string) * sizeof(char));
	if(tempString == NULL) {
		return NULL;
	}

	strcpy(tempString, string);

	len = searchStart - string;
	string[len] = '\0';

	strcat(string, replace);

	len += strlen(search);
	strcat(string, (char*)tempString+len);

	free(tempString);

	return string;
}


String split(String s, char parser, int index) {
  String rs="";
  int parserIndex = index;
  int parserCnt=0;
  int rFromIndex=0, rToIndex=-1;
  while (index >= parserCnt) {
    rFromIndex = rToIndex+1;
    rToIndex = s.indexOf(parser,rFromIndex);
    if (index == parserCnt) {
      //if (rToIndex < 0 || rToIndex < -1) return "";
      return s.substring(rFromIndex,rToIndex);
    } else parserCnt++;
  }
  return rs;
}