source: MondoRescue/branches/3.3/mindi-busybox/libbb/strrstr.c@ 3647

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 2008 Bernhard Reutner-Fischer
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"

/*
 * The strrstr() function finds the last occurrence of the substring needle
 * in the string haystack. The terminating nul characters are not compared.
 */
char* FAST_FUNC strrstr(const char *haystack, const char *needle)
{
    char *r = NULL;

    if (!needle[0])
        return (char*)haystack + strlen(haystack);
    while (1) {
        char *p = strstr(haystack, needle);
        if (!p)
            return r;
        r = p;
        haystack = p + 1;
    }
}

#if ENABLE_UNIT_TEST

BBUNIT_DEFINE_TEST(strrstr)
{
    static const struct {
        const char *h, *n;
        int pos;
    } test_array[] = {
        /* 0123456789 */
        { "baaabaaab",  "aaa", 5  },
        { "baaabaaaab", "aaa", 6  },
        { "baaabaab",   "aaa", 1  },
        { "aaa",        "aaa", 0  },
        { "aaa",        "a",   2  },
        { "aaa",        "bbb", -1 },
        { "a",          "aaa", -1 },
        { "aaa",        "",    3  },
        { "",           "aaa", -1 },
        { "",           "",    0  },
    };

    int i;

    i = 0;
    while (i < sizeof(test_array) / sizeof(test_array[0])) {
        const char *r = strrstr(test_array[i].h, test_array[i].n);
        if (r == NULL)
            r = test_array[i].h - 1;
        BBUNIT_ASSERT_EQ(r, test_array[i].h + test_array[i].pos);
        i++;
    }

    BBUNIT_ENDTEST;
}

#endif /* ENABLE_UNIT_TEST */