root / prex-0.9.0 / usr / lib / libc / string / bcopy.c @ 03e9c04a
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/*-
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Chris Torek.
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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 University nor the names of its 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 REGENTS 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 REGENTS 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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#include <sys/cdefs.h> |
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#include <string.h> |
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/*
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* Copy a block of memory, handling overlap.
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* This is the routine that actually implements
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* (the portable versions of) bcopy, memcpy, and memmove.
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*/
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#ifdef MEMCOPY
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void *
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memcpy(dst0, src0, length) |
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#else
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#ifdef MEMMOVE
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void *
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memmove(dst0, src0, length) |
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#else
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void
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bcopy(src0, dst0, length) |
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#endif
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#endif
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void *dst0;
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const void *src0; |
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size_t length; |
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{ |
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char *dst = dst0;
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const char *src = src0; |
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if (length == 0 || dst == src) /* nothing to do */ |
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goto done;
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if (((unsigned long)dst < (unsigned long)src) && |
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((unsigned long)dst < (unsigned long)src + length)) { |
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/* Copy backwards. */
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src += length; |
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dst += length; |
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while (length--) {
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*--dst = *--src; |
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} |
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} else {
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while (length--) {
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*dst++ = *src++; |
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} |
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} |
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done:
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#if defined(MEMCOPY) || defined(MEMMOVE)
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return (dst0);
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#else
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return;
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#endif
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} |