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 char*
utfrune(char * s,long c)20 utfrune(char *s, long c)
21 {
22 long c1;
23 Rune r;
24 int n;
25
26 if(c < Runesync) /* not part of utf sequence */
27 return strchr(s, c);
28
29 for(;;) {
30 c1 = *(uchar*)s;
31 if(c1 < Runeself) { /* one byte rune */
32 if(c1 == 0)
33 return 0;
34 if(c1 == c)
35 return s;
36 s++;
37 continue;
38 }
39 n = chartorune(&r, s);
40 if(r == c)
41 return s;
42 s += n;
43 }
44 }
45