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/*-

 * Copyright (c) 2005-2006, Kohsuke Ohtani

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the author nor the names of any co-contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/*

 * string.c - Minimum string library for kernel

 */

#include <kernel.h>

/*

 * Safer version of strncpy

 * The destination string is always terminated with NULL character.

 */

size_t

strlcpy(char *dest, const char *src, size_t count)

{

        char *d = dest;

        const char *s = src;

        size_t n = count;

        /* Copy as many bytes as will fit */

        if (n != 0 && --n != 0) {

                do {

                        if ((*d++ = *s++) == 0)

                                break;

                } while (--n != 0);

        }

        /* Not enough room in dst, add NUL and traverse rest of src */

        if (n == 0) {

                if (count != 0)

                        *d = '\0';                /* NUL-terminate dst */

                while (*s++)

                        ;

        }

        return (size_t)(s - src - 1);        /* count does not include NUL */

}

int

strncmp(const char *src, const char *tgt, size_t count)

{

        signed char res = 0;

        while (count) {

                if ((res = *src - *tgt++) != 0 || !*src++)

                        break;

                count--;

        }

        return res;

}

/* The returned size does not include the last NULL char */

size_t

strnlen(const char *str, size_t count)

{

        const char *tmp;

        for (tmp = str; count-- && *tmp != '\0'; ++tmp);

        return (size_t)(tmp - str);

}

void *

memcpy(void *dest, const void *src, size_t count)

{

        char *tmp = (char *)dest, *s = (char *)src;

        ASSERT(count != 0);

        while (count--)

                *tmp++ = *s++;

        return dest;

}

void *

memset(void *dest, int ch, size_t count)

{

        char *p = (char *)dest;

        ASSERT(count != 0);

        while (count--)

                *p++ = (char)ch;

        return dest;

}