runestrstr.c (1221B) download
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/*
21 * Return pointer to first occurrence of s2 in s1,
22 * 0 if none
23 */
24Rune* runestrstr(Rune* s1, Rune* s2) {
25 Rune * p, *pa, *pb;
26 unsigned int c0, c;
27
28 c0 = *s2;
29 if (c0 == 0)
30 return s1;
31 s2++;
32 for (p = runestrchr(s1, c0); p; p = runestrchr(p + 1, c0)) {
33 pa = p;
34 for (pb = s2;; pb++) {
35 c = *pb;
36 if (c == 0)
37 return p;
38 if (c != *++pa)
39 break;
40 }
41 }
42 return 0;
43}