/* * The authors of this software are Rob Pike and Ken Thompson. *              Copyright (c) 2002 by Lucent Technologies. * Permission to use, copy, modify, and distribute this software for any * purpose without fee is hereby granted, provided that this entire notice * is included in all copies of any software which is or includes a copy * or modification of this software and in all copies of the supporting * documentation for such software. * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE * ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */#include <stdlib.h>#include <string.h> #include "utf.h" typedef unsigned char uchar; enum{	Bit1	= 7,	Bitx	= 6,	Bit2	= 5,	Bit3	= 4,	Bit4	= 3,	Bit5	= 2, 	T1	= ((1<<(Bit1+1))-1) ^ 0xFF,	/* 0000 0000 */	Tx	= ((1<<(Bitx+1))-1) ^ 0xFF,	/* 1000 0000 */	T2	= ((1<<(Bit2+1))-1) ^ 0xFF,	/* 1100 0000 */	T3	= ((1<<(Bit3+1))-1) ^ 0xFF,	/* 1110 0000 */	T4	= ((1<<(Bit4+1))-1) ^ 0xFF,	/* 1111 0000 */	T5	= ((1<<(Bit5+1))-1) ^ 0xFF,	/* 1111 1000 */ 	Rune1	= (1<<(Bit1+0*Bitx))-1,		/* 0000 0000 0000 0000 0111 1111 */	Rune2	= (1<<(Bit2+1*Bitx))-1,		/* 0000 0000 0000 0111 1111 1111 */	Rune3	= (1<<(Bit3+2*Bitx))-1,		/* 0000 0000 1111 1111 1111 1111 */	Rune4	= (1<<(Bit4+3*Bitx))-1,		/* 0001 1111 1111 1111 1111 1111 */ 	Maskx	= (1<<Bitx)-1,			/* 0011 1111 */	Testx	= Maskx ^ 0xFF,			/* 1100 0000 */ 	Bad	= Runeerror}; intchartorune(Rune *rune, const char *str){	int c, c1, c2, c3;	int l; 	/* overlong null character */	if((uchar)str[0] == 0xc0 && (uchar)str[1] == 0x80) {		*rune = 0;		return 2;	} 	/*	 * one character sequence	 *	00000-0007F => T1	 */	c = *(uchar*)str;	if(c < Tx) {		*rune = c;		return 1;	} 	/*	 * two character sequence	 *	0080-07FF => T2 Tx	 */	c1 = *(uchar*)(str+1) ^ Tx;	if(c1 & Testx)		goto bad;	if(c < T3) {		if(c < T2)			goto bad;		l = ((c << Bitx) | c1) & Rune2;		if(l <= Rune1)			goto bad;		*rune = l;		return 2;	} 	/*	 * three character sequence	 *	0800-FFFF => T3 Tx Tx	 */	c2 = *(uchar*)(str+2) ^ Tx;	if(c2 & Testx)		goto bad;	if(c < T4) {		l = ((((c << Bitx) | c1) << Bitx) | c2) & Rune3;		if(l <= Rune2)			goto bad;		*rune = l;		return 3;	} 	/*	 * four character sequence	 *	10000-10FFFF => T4 Tx Tx Tx	 */	if(UTFmax >= 4) {		c3 = *(uchar*)(str+3) ^ Tx;		if(c3 & Testx)			goto bad;		if(c < T5) {			l = ((((((c << Bitx) | c1) << Bitx) | c2) << Bitx) | c3) & Rune4;			if(l <= Rune3)				goto bad;			if(l > Runemax)				goto bad;			*rune = l;			return 4;		}	} 	/*	 * bad decoding	 */bad:	*rune = Bad;	return 1;} intrunetochar(char *str, const Rune *rune){	int c = *rune; 	/* overlong null character */	if (c == 0) {		str[0] = (char)0xc0;		str[1] = (char)0x80;		return 2;	} 	/*	 * one character sequence	 *	00000-0007F => 00-7F	 */	if(c <= Rune1) {		str[0] = c;		return 1;	} 	/*	 * two character sequence	 *	00080-007FF => T2 Tx	 */	if(c <= Rune2) {		str[0] = T2 | (c >> 1*Bitx);		str[1] = Tx | (c & Maskx);		return 2;	} 	/*	 * three character sequence	 *	00800-0FFFF => T3 Tx Tx	 */	if(c > Runemax)		c = Runeerror;	if(c <= Rune3) {		str[0] = T3 |  (c >> 2*Bitx);		str[1] = Tx | ((c >> 1*Bitx) & Maskx);		str[2] = Tx |  (c & Maskx);		return 3;	} 	/*	 * four character sequence	 *	010000-1FFFFF => T4 Tx Tx Tx	 */	str[0] = T4 |  (c >> 3*Bitx);	str[1] = Tx | ((c >> 2*Bitx) & Maskx);	str[2] = Tx | ((c >> 1*Bitx) & Maskx);	str[3] = Tx |  (c & Maskx);	return 4;} intrunelen(int c){	Rune rune;	char str[10]; 	rune = c;	return runetochar(str, &rune);} intutflen(const char *s){	int c;	int n;	Rune rune; 	n = 0;	for(;;) {		c = *(uchar*)s;		if(c < Runeself) {			if(c == 0)				return n;			s++;		} else			s += chartorune(&rune, s);		n++;	}}