1 | /* $OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1998 Todd C. Miller <[email protected]> |
5 | * |
6 | * Permission to use, copy, modify, and distribute this software for any |
7 | * purpose with or without fee is hereby granted, provided that the above |
8 | * copyright notice and this permission notice appear in all copies. |
9 | * |
10 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
11 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
12 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
13 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
14 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
15 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
16 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
17 | */ |
18 | |
19 | #include <sys/types.h> |
20 | #include <string.h> |
21 | |
22 | #include "compat.h" |
23 | |
24 | /* |
25 | * Appends src to string dst of size siz (unlike strncat, siz is the |
26 | * full size of dst, not space left). At most siz-1 characters |
27 | * will be copied. Always NUL terminates (unless siz <= strlen(dst)). |
28 | * Returns strlen(src) + MIN(siz, strlen(initial dst)). |
29 | * If retval >= siz, truncation occurred. |
30 | */ |
31 | size_t |
32 | strlcat(char *dst, const char *src, size_t siz) |
33 | { |
34 | char *d = dst; |
35 | const char *s = src; |
36 | size_t n = siz; |
37 | size_t dlen; |
38 | |
39 | /* Find the end of dst and adjust bytes left but don't go past end */ |
40 | while (n-- != 0 && *d != '\0') |
41 | d++; |
42 | dlen = d - dst; |
43 | n = siz - dlen; |
44 | |
45 | if (n == 0) |
46 | return(dlen + strlen(s)); |
47 | while (*s != '\0') { |
48 | if (n != 1) { |
49 | *d++ = *s; |
50 | n--; |
51 | } |
52 | s++; |
53 | } |
54 | *d = '\0'; |
55 | |
56 | return(dlen + (s - src)); /* count does not include NUL */ |
57 | } |
58 | |