utfnlen.c (1111B)
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 <stdarg.h> 15 #include <string.h> 16 #include "plan9.h" 17 #include "utf.h" 18 19 int 20 utfnlen(char *s, long m) 21 { 22 int c; 23 long n; 24 Rune rune; 25 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 }