ref: ca3c7e43416b28d3b58a455e0a4068fa845fdfba
dir: /utf.c/
/*
* 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,
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 */
Rune1 = (1<<(Bit1+0*Bitx))-1, /* 0000 0000 0111 1111 */
Rune2 = (1<<(Bit2+1*Bitx))-1, /* 0000 0111 1111 1111 */
Rune3 = (1<<(Bit3+2*Bitx))-1, /* 1111 1111 1111 1111 */
Maskx = (1<<Bitx)-1, /* 0011 1111 */
Testx = Maskx ^ 0xFF, /* 1100 0000 */
Bad = Runeerror,
};
int
chartorune(Rune *rune, const char *str)
{
int c, c1, c2;
long l;
/*
* 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;
}
/*
* bad decoding
*/
bad:
*rune = Bad;
return 1;
}
int
runetochar(char *str, const Rune *rune)
{
long c;
/*
* one character sequence
* 00000-0007F => 00-7F
*/
c = *rune;
if(c <= Rune1) {
str[0] = c;
return 1;
}
/*
* two character sequence
* 0080-07FF => T2 Tx
*/
if(c <= Rune2) {
str[0] = T2 | (c >> 1*Bitx);
str[1] = Tx | (c & Maskx);
return 2;
}
/*
* three character sequence
* 0800-FFFF => T3 Tx Tx
*/
str[0] = T3 | (c >> 2*Bitx);
str[1] = Tx | ((c >> 1*Bitx) & Maskx);
str[2] = Tx | (c & Maskx);
return 3;
}
int
runelen(long c)
{
Rune rune;
char str[10];
rune = c;
return runetochar(str, &rune);
}
int
runenlen(const Rune *r, int nrune)
{
int nb, c;
nb = 0;
while(nrune--) {
c = *r++;
if(c <= Rune1)
nb++;
else
if(c <= Rune2)
nb += 2;
else
nb += 3;
}
return nb;
}
int
fullrune(const char *str, int n)
{
int c;
if(n > 0) {
c = *(uchar*)str;
if(c < Tx)
return 1;
if(n > 1)
if(c < T3 || n > 2)
return 1;
}
return 0;
}
Rune*
runestrcat(Rune *s1, const Rune *s2)
{
runestrcpy(runestrchr(s1, 0), s2);
return s1;
}
Rune*
runestrchr(const Rune *s, Rune c)
{
Rune c0 = c;
Rune c1;
if(c == 0) {
while(*s++)
;
return (Rune*) s-1;
}
while((c1 = *s++))
if(c1 == c0)
return (Rune*) s-1;
return 0;
}
int
runestrcmp(const Rune *s1, const Rune *s2)
{
Rune c1, c2;
for(;;) {
c1 = *s1++;
c2 = *s2++;
if(c1 != c2) {
if(c1 > c2)
return 1;
return -1;
}
if(c1 == 0)
return 0;
}
}
Rune*
runestrcpy(Rune *s1, const Rune *s2)
{
Rune *os1;
os1 = s1;
while((*s1++ = *s2++))
;
return os1;
}
Rune*
runestrdup(const Rune *s)
{
Rune *ns;
ns = malloc(sizeof(Rune)*(runestrlen(s) + 1));
if(ns == 0)
return 0;
return runestrcpy(ns, s);
}
Rune*
runestrecpy(Rune *s1, Rune *es1, const Rune *s2)
{
if(s1 >= es1)
return s1;
while((*s1++ = *s2++)){
if(s1 == es1){
*--s1 = '\0';
break;
}
}
return s1;
}
long
runestrlen(const Rune *s)
{
return runestrchr(s, 0) - s;
}
Rune*
runestrncat(Rune *s1, const Rune *s2, long n)
{
Rune *os1;
os1 = s1;
s1 = runestrchr(s1, 0);
while((*s1++ = *s2++))
if(--n < 0) {
s1[-1] = 0;
break;
}
return os1;
}
int
runestrncmp(const Rune *s1, const Rune *s2, long n)
{
Rune c1, c2;
while(n > 0) {
c1 = *s1++;
c2 = *s2++;
n--;
if(c1 != c2) {
if(c1 > c2)
return 1;
return -1;
}
if(c1 == 0)
break;
}
return 0;
}
Rune*
runestrncpy(Rune *s1, const Rune *s2, long n)
{
int i;
Rune *os1;
os1 = s1;
for(i = 0; i < n; i++)
if((*s1++ = *s2++) == 0) {
while(++i < n)
*s1++ = 0;
return os1;
}
return os1;
}
Rune*
runestrrchr(const Rune *s, Rune c)
{
Rune *r;
if(c == 0)
return runestrchr(s, 0);
r = 0;
while((s = runestrchr(s, c)))
r = (Rune*) s++;
return r;
}
/*
* Return pointer to first occurrence of s2 in s1,
* 0 if none
*/
Rune*
runestrstr(const Rune *s1, const Rune *s2)
{
const Rune *p, *pa, *pb;
int c0, c;
c0 = *s2;
if(c0 == 0)
return (Rune*) s1;
s2++;
for(p=runestrchr(s1, c0); p; p=runestrchr(p+1, c0)) {
pa = p;
for(pb=s2;; pb++) {
c = *pb;
if(c == 0)
return (Rune*) p;
if(c != *++pa)
break;
}
}
return 0;
}
char*
utfecpy(char *to, char *e, const char *from)
{
char *end;
if(to >= e)
return to;
end = memccpy(to, from, '\0', e - to);
if(end == 0){
end = e-1;
while(end>to && (*--end&0xC0)==0x80)
;
*end = '\0';
}else{
end--;
}
return end;
}
int
utflen(const char *s)
{
int c;
long n;
Rune rune;
n = 0;
for(;;) {
c = *(uchar*)s;
if(c < Runeself) {
if(c == 0)
return n;
s++;
} else
s += chartorune(&rune, s);
n++;
}
}
int
utfnlen(const char *s, long m)
{
int c;
long n;
Rune rune;
const char *es;
es = s + m;
for(n = 0; s < es; n++) {
c = *(uchar*)s;
if(c < Runeself){
if(c == '\0')
break;
s++;
continue;
}
if(!fullrune(s, es-s))
break;
s += chartorune(&rune, s);
}
return n;
}
char*
utfrrune(const char *s, long c)
{
long c1;
Rune r;
const char *s1;
if(c < Runesync) /* not part of utf sequence */
return strrchr(s, c);
s1 = 0;
for(;;) {
c1 = *(uchar*)s;
if(c1 < Runeself) { /* one byte rune */
if(c1 == 0)
return (char*) s1;
if(c1 == c)
s1 = s;
s++;
continue;
}
c1 = chartorune(&r, s);
if(r == c)
s1 = s;
s += c1;
}
}
char*
utfrune(const char *s, long c)
{
long c1;
Rune r;
int n;
if(c < Runesync) /* not part of utf sequence */
return strchr(s, c);
for(;;) {
c1 = *(uchar*)s;
if(c1 < Runeself) { /* one byte rune */
if(c1 == 0)
return 0;
if(c1 == c)
return (char*) s;
s++;
continue;
}
n = chartorune(&r, s);
if(r == c)
return (char*) s;
s += n;
}
}
/*
* Return pointer to first occurrence of s2 in s1,
* 0 if none
*/
char*
utfutf(const char *s1, const char *s2)
{
const char *p;
long f, n1, n2;
Rune r;
n1 = chartorune(&r, s2);
f = r;
if(f <= Runesync) /* represents self */
return strstr(s1, s2);
n2 = strlen(s2);
for(p=s1; (p=utfrune(p, f)); p+=n1)
if(strncmp(p, s2, n2) == 0)
return (char*) p;
return 0;
}