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[glibc.git] / wcsmbs / wcsncat.c
blob8ff149e8833f41e0ec45bfd63181d12dbda9e12f
1 /* Copyright (C) 1995, 1996, 1997 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.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <wchar.h>
23 /* Append no more than N wide-character of SRC onto DEST. */
24 wchar_t *
25 wcsncat (dest, src, n)
26 wchar_t *dest;
27 const wchar_t *src;
28 size_t n;
30 wchar_t c;
31 wchar_t * const s = dest;
33 /* Find the end of DEST. */
35 c = *dest++;
36 while (c != L'\0');
38 /* Make DEST point before next character, so we can increment
39 it while memory is read (wins on pipelined cpus). */
40 dest -= 2;
42 if (n >= 4)
44 size_t n4 = n >> 2;
47 c = *src++;
48 *++dest = c;
49 if (c == L'\0')
50 return s;
51 c = *src++;
52 *++dest = c;
53 if (c == L'\0')
54 return s;
55 c = *src++;
56 *++dest = c;
57 if (c == L'\0')
58 return s;
59 c = *src++;
60 *++dest = c;
61 if (c == L'\0')
62 return s;
63 } while (--n4 > 0);
64 n &= 3;
67 while (n > 0)
69 c = *src++;
70 *++dest = c;
71 if (c == L'\0')
72 return s;
73 n--;
76 if (c != L'\0')
77 *++dest = L'\0';
79 return s;