char16.c

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef short char16;

#define char_bit1(c) ((c) & 1)
#define char_bit2(c) (((c) & 2) >> 1)
#define char_bit3(c) (((c) & 4) >> 2)
#define char_bit4(c) (((c) & 8) >> 3)
#define char_bit5(c) (((c) & 16) >> 4)
#define char_bit6(c) (((c) & 32) >> 5)
#define char_bit7(c) (((c) & 64) >> 6)
#define char_bit8(c) (((c) & 128) >> 7)
#define length(c) ((!char_bit8((c)) || (char_bit8(c) && !char_bit7(c)))? 1 : 2)
/*
int length(char c)
{
  if(!char_bit8(c)) return 1;
  if(char_bit8(c) && !char_bit7(c)) return 1;
  if(char_bit7(c)) return 2;
  if(char_bit6(c)) return 3;
  if(char_bit5(4)) return 4;
  
}
*/
int utf8_strlen(char *utf8_string)
{
  int l = 0;
  while(*utf8_string){
    l += (length(*utf8_string) == 1) ? 1 : 0;
    utf8_string++;
  }
  return l;
}

char *char16toutf8(char16 *char16_string)
{
  
}


int char16_strlen(char16 *string)
{
  int i=0;
  while(string[i]) i++;
  return i;
}

char16 *utf8tochar16(char *utf8_string)
{
  char16 c16;
  int i,j;
  int utf8_length = strlen(utf8_string);
  int char16_length = 0;
  char16 *char16_string;
  for(i=0; i < utf8_length; i++)
    char16_length += length(utf8_string[i]);
  
  char16_string = malloc((char16_length + 1)* sizeof(char));
  for(i=0, j=0; i < utf8_length; i++, j++){
    if(length(utf8_string[i]) == 1){
      char16_string[j] = (char16)utf8_string[i];
    }
    if(length(utf8_string[i]) == 2){
      char16_string[j] = utf8_string[i];
      char16_string[j] << 8;
      char16_string[j] += utf8_string[++i];
    }
  }
  char16_string[j] = 0;
  return char16_string;
}

int main(void)
{
  int i;
  char string[200];
  char16 *char16_string;
  strcpy(string, "élémentaire");
  /* strcpy(string, "konjunktúra-időszaknál"); */

  printf("string = %s\n", string);
  printf("length = %d\n", (int)strlen(string));
  printf("utf8 length = %d\n", (int)utf8_strlen(string));
  for(i=0; i < strlen(string); i++){
    printf("%d\t%c\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\tl=%d\n", i, string[i], (int)string[i], char_bit1(string[i]), char_bit2(string[i]), char_bit3(string[i]), char_bit4(string[i]), char_bit5(string[i]), char_bit6(string[i]), char_bit7(string[i]), char_bit8(string[i]), length(string[i])); 
  }


  char16_string = utf8tochar16(string);
  printf("char16_strlen = %d\n", char16_strlen(char16_string));
  
}