cosmopolitan/libc/mem/strndup.c

41 lines
2.3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 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/mem/mem.h"
#include "libc/str/str.h"
/**
* Allocates new copy of string, with byte limit.
*
* @param s is a NUL-terminated byte string
* @param n if less than strlen(s) will truncate the string
* @return new string or NULL w/ errno
* @error ENOMEM
*/
char *strndup(const char *s, size_t n) {
char *s2;
size_t len = strnlen(s, n);
if ((s2 = malloc(len + 1))) {
memcpy(s2, s, len);
s2[len] = '\0';
return s2;
}
return s2;
}