/*

#include	<sys/types.h>

#include	<stdio.h>

#include	<stdlib.h>

#include	<string.h>

#include	<unistd.h>

#include	<errno.h>

*/

/*

	the our_* routines are implementations for the corresponding library

	routines. for a while, i tried to actually name them wctomb etc

	but stopped that after i found a system which made wchar_t an

	unsigned char.

*/

enum {

	T1 = 0x00,

	Tx = 0x80,

	T2 = 0xC0,

	T3 = 0xE0,

	T4 = 0xF0,

	T5 = 0xF8,

	T6 = 0xFC,

	Bit1 = 7,

	Bitx = 6,

	Bit2 = 5,

	Bit3 = 4,

	Bit4 = 3,

	Bit5 = 2,

	Bit6 = 2,

	Mask1 = (1 << Bit1) - 1,

	Maskx = (1 << Bitx) - 1,

	Mask2 = (1 << Bit2) - 1,

	Mask3 = (1 << Bit3) - 1,

	Mask4 = (1 << Bit4) - 1,

	Mask5 = (1 << Bit5) - 1,

	Mask6 = (1 << Bit6) - 1,

	Wchar1 = (1UL << Bit1) - 1,

	Wchar2 = (1UL << (Bit2 + Bitx)) - 1,

	Wchar3 = (1UL << (Bit3 + 2 * Bitx)) - 1,

	Wchar4 = (1UL << (Bit4 + 3 * Bitx)) - 1,

	Wchar5 = (1UL << (Bit5 + 4 * Bitx)) - 1

#ifndef EILSEQ

	, /* we hate ansi c's comma rules */

	EILSEQ = 123

#endif /* PLAN9 */

};

static int

our_wctomb(char *s, unsigned long wc)

{

	if (s == 0)

		return 0; /* no shift states */

	if (wc & ~Wchar2) {

		if (wc & ~Wchar4) {

			if (wc & ~Wchar5) {

				/* 6 bytes */

				s[0] = T6 | ((wc >> 5 * Bitx) & Mask6);

				s[1] = Tx | ((wc >> 4 * Bitx) & Maskx);

				s[2] = Tx | ((wc >> 3 * Bitx) & Maskx);

				s[3] = Tx | ((wc >> 2 * Bitx) & Maskx);

				s[4] = Tx | ((wc >> 1 * Bitx) & Maskx);

				s[5] = Tx | (wc & Maskx);

				return 6;

			}

			/* 5 bytes */

			s[0] = T5 | (wc >> 4 * Bitx);

			s[1] = Tx | ((wc >> 3 * Bitx) & Maskx);

			s[2] = Tx | ((wc >> 2 * Bitx) & Maskx);

			s[3] = Tx | ((wc >> 1 * Bitx) & Maskx);

			s[4] = Tx | (wc & Maskx);

			return 5;

		}

		if (wc & ~Wchar3) {

			/* 4 bytes */

			s[0] = T4 | (wc >> 3 * Bitx);

			s[1] = Tx | ((wc >> 2 * Bitx) & Maskx);

			s[2] = Tx | ((wc >> 1 * Bitx) & Maskx);

			s[3] = Tx | (wc & Maskx);

			return 4;

		}

		/* 3 bytes */

		s[0] = T3 | (wc >> 2 * Bitx);

		s[1] = Tx | ((wc >> 1 * Bitx) & Maskx);

		s[2] = Tx | (wc & Maskx);

		return 3;

	}

	if (wc & ~Wchar1) {

		/* 2 bytes */

		s[0] = T2 | (wc >> 1 * Bitx);

		s[1] = Tx | (wc & Maskx);

		return 2;

	}

	/* 1 byte */

	s[0] = T1 | wc;

	return 1;

}