56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
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/* $OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $ */
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/*
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* Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/types.h>
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#include <string.h>
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/*
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* Appends src to string dst of size dsize (unlike strncat, dsize is the
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* full size of dst, not space left). At most dsize-1 characters
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* will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
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* Returns strlen(src) + MIN(dsize, strlen(initial dst)).
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* If retval >= dsize, truncation occurred.
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*/
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size_t
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strlcat(char *dst, const char *src, size_t dsize)
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{
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const char *odst = dst;
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const char *osrc = src;
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size_t n = dsize;
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size_t dlen;
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/* Find the end of dst and adjust bytes left but don't go past end. */
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while (n-- != 0 && *dst != '\0')
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dst++;
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dlen = dst - odst;
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n = dsize - dlen;
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if (n-- == 0)
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return(dlen + strlen(src));
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while (*src != '\0') {
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if (n != 0) {
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*dst++ = *src;
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n--;
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}
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src++;
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}
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*dst = '\0';
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return(dlen + (src - osrc)); /* count does not include NUL */
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}
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