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/*-
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 * Copyright (c) 2005-2006, Kohsuke Ohtani
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the author nor the names of any co-contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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/*
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 * string.c - Minimum string library for kernel
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 */
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#include <kernel.h>
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/*
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 * Safer version of strncpy
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 * The destination string is always terminated with NULL character.
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 */
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size_t
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strlcpy(char *dest, const char *src, size_t count)
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{
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        char *d = dest;
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        const char *s = src;
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        size_t n = count;
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        /* Copy as many bytes as will fit */
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        if (n != 0 && --n != 0) {
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                do {
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                        if ((*d++ = *s++) == 0)
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                                break;
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                } while (--n != 0);
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        }
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        /* Not enough room in dst, add NUL and traverse rest of src */
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        if (n == 0) {
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                if (count != 0)
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                        *d = '\0';                /* NUL-terminate dst */
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                while (*s++)
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                        ;
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        }
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        return (size_t)(s - src - 1);        /* count does not include NUL */
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}
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int
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strncmp(const char *src, const char *tgt, size_t count)
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{
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        signed char res = 0;
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        while (count) {
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                if ((res = *src - *tgt++) != 0 || !*src++)
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                        break;
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                count--;
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        }
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        return res;
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}
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/* The returned size does not include the last NULL char */
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size_t
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strnlen(const char *str, size_t count)
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{
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        const char *tmp;
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        for (tmp = str; count-- && *tmp != '\0'; ++tmp);
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        return (size_t)(tmp - str);
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}
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void *
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memcpy(void *dest, const void *src, size_t count)
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{
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        char *tmp = (char *)dest, *s = (char *)src;
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        ASSERT(count != 0);
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        while (count--)
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                *tmp++ = *s++;
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        return dest;
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}
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void *
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memset(void *dest, int ch, size_t count)
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{
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        char *p = (char *)dest;
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        ASSERT(count != 0);
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        while (count--)
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                *p++ = (char)ch;
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        return dest;
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}