1/* Copyright (C) 1996-2019 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <wchar.h>
20
21#ifdef WCPNCPY
22# define __wcpncpy WCPNCPY
23#endif
24
25/* Copy no more than N wide-characters of SRC to DEST, returning the
26 address of the last character written into DEST. */
27wchar_t *
28__wcpncpy (wchar_t *dest, const wchar_t *src, size_t n)
29{
30 wint_t c;
31 wchar_t *const s = dest;
32
33 if (n >= 4)
34 {
35 size_t n4 = n >> 2;
36
37 for (;;)
38 {
39 c = *src++;
40 *dest++ = c;
41 if (c == L'\0')
42 break;
43 c = *src++;
44 *dest++ = c;
45 if (c == L'\0')
46 break;
47 c = *src++;
48 *dest++ = c;
49 if (c == L'\0')
50 break;
51 c = *src++;
52 *dest++ = c;
53 if (c == L'\0')
54 break;
55 if (--n4 == 0)
56 goto last_chars;
57 }
58 n -= dest - s;
59 goto zero_fill;
60 }
61
62 last_chars:
63 n &= 3;
64 if (n == 0)
65 return dest;
66
67 for (;;)
68 {
69 c = *src++;
70 --n;
71 *dest++ = c;
72 if (c == L'\0')
73 break;
74 if (n == 0)
75 return dest;
76 }
77
78 zero_fill:
79 while (n-- > 0)
80 dest[n] = L'\0';
81
82 return dest - 1;
83}
84
85#ifndef WCPNCPY
86weak_alias (__wcpncpy, wcpncpy)
87#endif
88