Add memchr tests for n == 0
[glibc.git] / string / strncat.c
blob71a13eec0b865332006810489c087d586ecf7095
1 /* Copyright (C) 1991-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
18 #include <string.h>
20 #ifndef STRNCAT
21 # undef strncat
22 # define STRNCAT strncat
23 #endif
25 char *
26 STRNCAT (char *s1, const char *s2, size_t n)
28 char *s = s1;
30 /* Find the end of S1. */
31 s1 += strlen (s1);
33 size_t ss = __strnlen (s2, n);
35 s1[ss] = '\0';
36 memcpy (s1, s2, ss);
38 return s;