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 ANY
11 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
12 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
13 */
14 #include <stdarg.h>
15 #include <string.h>
16 #include "utf.h"
17 #include "utfdef.h"
18
19 int
utfnlen(const char * s,long m)20 utfnlen(const char *s, long m)
21 {
22 int c;
23 long n;
24 Rune rune;
25 const char *es;
26
27 es = s + m;
28 for(n = 0; s < es; n++) {
29 c = *(uchar*)s;
30 if(c < Runeself){
31 if(c == '\0')
32 break;
33 s++;
34 continue;
35 }
36 if(!fullrune(s, es-s))
37 break;
38 s += chartorune(&rune, s);
39 }
40 return n;
41 }
42