utfnlen.c (1124B) download
1/*
2 * The authors of this software are Rob Pike and Ken Thompson.
3 * Copyright (c) 2002 by Lucent Technologies.
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose without fee is hereby granted, provided that this entire notice
6 * is included in all copies of any software which is or includes a copy
7 * or modification of this software and in all copies of the supporting
8 * documentation for such software.
9 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
10 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
11 * ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
12 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
13 */
14#include "plan9.h"
15#include "utf.h"
16
17#include <stdarg.h>
18#include <string.h>
19
20int utfnlen(char* s, long m) {
21 int c;
22 long n;
23 Rune rune;
24 char* es;
25
26 es = s + m;
27 for (n = 0; s < es; n++) {
28 c = *(uchar*) s;
29 if (c < Runeself) {
30 if (c == '\0')
31 break;
32 s++;
33 continue;
34 }
35 if (!fullrune(s, es - s))
36 break;
37 s += chartorune(&rune, s);
38 }
39 return n;
40}