| 1 | /* $OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp $ */ |
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| 2 | |
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| 3 | /* |
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| 4 | * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> |
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| 5 | * All rights reserved. |
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| 6 | * |
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| 7 | * Redistribution and use in source and binary forms, with or without |
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| 8 | * modification, are permitted provided that the following conditions |
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| 9 | * are met: |
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| 10 | * 1. Redistributions of source code must retain the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer. |
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| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 13 | * notice, this list of conditions and the following disclaimer in the |
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| 14 | * documentation and/or other materials provided with the distribution. |
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| 15 | * 3. The name of the author may not be used to endorse or promote products |
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| 16 | * derived from this software without specific prior written permission. |
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| 17 | * |
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| 18 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, |
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| 19 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY |
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| 20 | * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL |
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| 21 | * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
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| 22 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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| 23 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
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| 24 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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| 25 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
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| 26 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
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| 27 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 28 | */ |
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| 29 | |
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| 30 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 31 | static char *rcsid = "$OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp $"; |
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| 32 | #endif /* LIBC_SCCS and not lint */ |
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| 33 | |
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| 34 | #include <string.h> |
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| 35 | |
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| 36 | /* |
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| 37 | * Appends src to string dst of size siz (unlike strncat, siz is the |
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| 38 | * full size of dst, not space left). At most siz-1 characters |
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| 39 | * will be copied. Always NUL terminates (unless siz == 0). |
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| 40 | * Returns strlen(initial dst) + strlen(src); if retval >= siz, |
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| 41 | * truncation occurred. |
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| 42 | */ |
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| 43 | size_t strlcat(dst, src, siz) |
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| 44 | char *dst; |
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| 45 | const char *src; |
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| 46 | size_t siz; |
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| 47 | { |
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| 48 | register char *d = dst; |
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| 49 | register const char *s = src; |
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| 50 | register size_t n = siz; |
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| 51 | size_t dlen; |
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| 52 | |
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| 53 | /* Find the end of dst and adjust bytes left but don't go past end */ |
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| 54 | while (*d != '\0' && n-- != 0) |
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| 55 | d++; |
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| 56 | dlen = d - dst; |
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| 57 | n = siz - dlen; |
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| 58 | |
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| 59 | if (n == 0) |
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| 60 | return(dlen + strlen(s)); |
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| 61 | while (*s != '\0') { |
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| 62 | if (n != 1) { |
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| 63 | *d++ = *s; |
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| 64 | n--; |
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| 65 | } |
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| 66 | s++; |
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| 67 | } |
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| 68 | *d = '\0'; |
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| 69 | |
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| 70 | return(dlen + (s - src)); /* count does not include NUL */ |
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| 71 | } |
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