#include <stdio.h>
#include <stdint.h>

/* UTF-8 representation
 bytes | bits | representation
     1 |    7 | 0vvvvvvv
     2 |   11 | 110vvvvv 10vvvvvv
     3 |   16 | 1110vvvv 10vvvvvv 10vvvvvv
     4 |   21 | 11110vvv 10vvvvvv 10vvvvvv 10vvvvvv
*/


/* takes a full UTF-4 character c and outputs it as a UTF-8 sequence */
void putwchar(uint32_t c)
{
  if (c < 0x80) {
    putchar (c);
  }
  else if (c < 0x800) {
    putchar (0xC0 | c>>6);
    putchar (0x80 | c & 0x3F);
  }
  else if (c < 0x10000) {
    putchar (0xE0 | c>>12);
    putchar (0x80 | c>>6 & 0x3F);
    putchar (0x80 | c & 0x3F);
  }
  else if (c < 0x200000) {
    putchar (0xF0 | c>>18);
    putchar (0x80 | c>>12 & 0x3F);
    putchar (0x80 | c>>6 & 0x3F);
    putchar (0x80 | c & 0x3F);
  }
}

int main(void)
{
    uint32_t ch;
    int i;

    for(i=0,ch=0x0020;ch<0x3400;ch++,i=(i+1)%16) {
        if(i==0) {
            printf("%06X: ",ch);
        }
        putwchar(ch);
        if(i==15) {
            putchar('\n');
        }
    }
}