Files
wget2/libwget/strscpy.c
2024-01-07 12:41:02 +01:00

71 lines
1.8 KiB
C

/*
* Copyright (c) 2017-2024 Free Software Foundation, Inc.
*
* This file is part of libwget.
*
* Libwget is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Libwget is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libwget. If not, see <https://www.gnu.org/licenses/>.
*
*/
#include <config.h>
#include <stddef.h>
#include <string.h>
#include <wget.h>
/**
* \ingroup libwget-utils
* \param[out] dst Output string buffer
* \param[in] src Input string
* \param[in] size Size of \p dst
* \return Number of copied bytes (excluding trailing 0) or -1 when \p src doesn't fit into \p dst
*
* Copy string \p src into \p dst with overflow checking.
*
* If either \p dst is %NULL or \p size is 0, the return value is -1 and nothing is written.
* If \p src is %NULL and size is 0, the return value is -1.
* If \p src is %NULL and size is >0, the return value is 0 and \p dst is an empty string.
*
* Else the return value is the number of bytes copied to \p dst excluding the terminating 0.
*/
ssize_t wget_strscpy(char *dst, const char *src, size_t size)
{
if (unlikely(!dst))
return -1;
if (unlikely(!src)) {
if (size) {
*dst = 0;
return 0;
} else
return -1;
}
const char *old = src;
// Copy as many bytes as will fit
if (likely(size)) {
while (--size) {
if (!(*dst++ = *src++))
return src - old - 1;
}
*dst = 0;
return src - old;
}
return -1;
}