root/src/lib9/utf/utfnlen.c

DEFINITIONS

1. utfnlen

/*
 * 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 "utf.h"
#include "utfdef.h"

int
utfnlen(const char *s, long m)
{
        int c;
        int 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, (int)(es-s)))
                        break;
                s += chartorune(&rune, s);
        }
        return n;
}