1 /* vi: set sw=4 ts=4: */
2 /*
3 * Utility routines.
4 *
5 * Copyright (C) 2008 Bernhard Reutner-Fischer
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9 #include "libbb.h"
10
11 /*
12 * The strrstr() function finds the last occurrence of the substring needle
13 * in the string haystack. The terminating nul characters are not compared.
14 */
strrstr(const char * haystack,const char * needle)15 char* FAST_FUNC strrstr(const char *haystack, const char *needle)
16 {
17 char *r = NULL;
18
19 if (!needle[0])
20 return (char*)haystack + strlen(haystack);
21 while (1) {
22 char *p = strstr(haystack, needle);
23 if (!p)
24 return r;
25 r = p;
26 haystack = p + 1;
27 }
28 }
29
30 #if ENABLE_UNIT_TEST
31
BBUNIT_DEFINE_TEST(strrstr)32 BBUNIT_DEFINE_TEST(strrstr)
33 {
34 static const struct {
35 const char *h, *n;
36 int pos;
37 } test_array[] = {
38 /* 0123456789 */
39 { "baaabaaab", "aaa", 5 },
40 { "baaabaaaab", "aaa", 6 },
41 { "baaabaab", "aaa", 1 },
42 { "aaa", "aaa", 0 },
43 { "aaa", "a", 2 },
44 { "aaa", "bbb", -1 },
45 { "a", "aaa", -1 },
46 { "aaa", "", 3 },
47 { "", "aaa", -1 },
48 { "", "", 0 },
49 };
50
51 int i;
52
53 i = 0;
54 while (i < sizeof(test_array) / sizeof(test_array[0])) {
55 const char *r = strrstr(test_array[i].h, test_array[i].n);
56 if (r == NULL)
57 r = test_array[i].h - 1;
58 BBUNIT_ASSERT_EQ(r, test_array[i].h + test_array[i].pos);
59 i++;
60 }
61
62 BBUNIT_ENDTEST;
63 }
64
65 #endif /* ENABLE_UNIT_TEST */
66