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strlcpy.c
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1 /*-------------------------------------------------------------------------
2  *
3  * strlcpy.c
4  * strncpy done right
5  *
6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7  *
8  *
9  * IDENTIFICATION
10  * src/port/strlcpy.c
11  *
12  * This file was taken from OpenBSD and is used on platforms that don't
13  * provide strlcpy(). The OpenBSD copyright terms follow.
14  *-------------------------------------------------------------------------
15  */
16 
17 /* $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $ */
18 
19 /*
20  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
21  *
22  * Permission to use, copy, modify, and distribute this software for any
23  * purpose with or without fee is hereby granted, provided that the above
24  * copyright notice and this permission notice appear in all copies.
25  *
26  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
27  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
28  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
29  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
30  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
31  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
32  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
33  */
34 
35 #include "c.h"
36 
37 
38 /*
39  * Copy src to string dst of size siz. At most siz-1 characters
40  * will be copied. Always NUL terminates (unless siz == 0).
41  * Returns strlen(src); if retval >= siz, truncation occurred.
42  * Function creation history: http://www.gratisoft.us/todd/papers/strlcpy.html
43  */
44 size_t
45 strlcpy(char *dst, const char *src, size_t siz)
46 {
47  char *d = dst;
48  const char *s = src;
49  size_t n = siz;
50 
51  /* Copy as many bytes as will fit */
52  if (n != 0)
53  {
54  while (--n != 0)
55  {
56  if ((*d++ = *s++) == '\0')
57  break;
58  }
59  }
60 
61  /* Not enough room in dst, add NUL and traverse rest of src */
62  if (n == 0)
63  {
64  if (siz != 0)
65  *d = '\0'; /* NUL-terminate dst */
66  while (*s++)
67  ;
68  }
69 
70  return (s - src - 1); /* count does not include NUL */
71 }
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45