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*
utfrrune(char * s,long c)20 utfrrune(char *s, long c)
21 {
22 long c1;
23 Rune r;
24 char *s1;
25
26 if(c < Runesync) /* not part of utf sequence */
27 return strrchr(s, c);
28
29 s1 = 0;
30 for(;;) {
31 c1 = *(uchar*)s;
32 if(c1 < Runeself) { /* one byte rune */
33 if(c1 == 0)
34 return s1;
35 if(c1 == c)
36 s1 = s;
37 s++;
38 continue;
39 }
40 c1 = chartorune(&r, s);
41 if(r == c)
42 s1 = s;
43 s += c1;
44 }
45 }
46