cosmopolitan/libc/str/strlcat.c

42 lines
2.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program 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 │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/safemacros.internal.h"
#include "libc/str/str.h"
/**
* Appends string SRC to DEST, the BSD way.
*
* @param dest is a buffer holding a NUL-terminated string
* @param src is a NUL-terminated string
* @param size is byte capacity of dest
* @return strlen(dest) + strlen(src)
* @note dest and src can't overlap
* @see strncat()
*/
size_t strlcat(char *dest, const char *src, size_t size) {
size_t destlen = strnlen(dest, size);
size_t srclen = strlen(src);
if (size) {
memcpy(&dest[destlen], src, min(srclen, size - destlen));
dest[min(destlen + srclen, size - 1)] = '\0';
}
return destlen + srclen;
}