postgresql/src/port/strlcpy.c

72 lines
2.0 KiB
C

/*-------------------------------------------------------------------------
*
* strlcpy.c
* strncpy done right
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
*
*
* IDENTIFICATION
* src/port/strlcpy.c
*
* This file was taken from OpenBSD and is used on platforms that don't
* provide strlcpy(). The OpenBSD copyright terms follow.
*-------------------------------------------------------------------------
*/
/* $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $ */
/*
* Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "c.h"
/*
* Copy src to string dst of size siz. At most siz-1 characters
* will be copied. Always NUL terminates (unless siz == 0).
* Returns strlen(src); if retval >= siz, truncation occurred.
* Function creation history: http://www.gratisoft.us/todd/papers/strlcpy.html
*/
size_t
strlcpy(char *dst, const char *src, size_t siz)
{
char *d = dst;
const char *s = src;
size_t n = siz;
/* Copy as many bytes as will fit */
if (n != 0)
{
while (--n != 0)
{
if ((*d++ = *s++) == '\0')
break;
}
}
/* Not enough room in dst, add NUL and traverse rest of src */
if (n == 0)
{
if (siz != 0)
*d = '\0'; /* NUL-terminate dst */
while (*s++)
;
}
return (s - src - 1); /* count does not include NUL */
}