utfnlen.c (1124B)
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 20 int 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 }