| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1996-2016 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. */ |
| 27 | wchar_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 |
| 86 | weak_alias (__wcpncpy, wcpncpy) |
| 87 | #endif |