lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2006-2007 Axis Communications AB |
| 3 | * |
| 4 | * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. |
| 5 | */ |
| 6 | |
| 7 | #include <string.h> |
| 8 | |
| 9 | |
| 10 | char *strncpy(char *dest, const char *src, size_t count) |
| 11 | { |
| 12 | char *ret = dest; |
| 13 | unsigned long himagic = 0x80808080L; |
| 14 | unsigned long lomagic = 0x01010101L; |
| 15 | |
| 16 | while (count && (unsigned long)src & (sizeof src - 1)) |
| 17 | { |
| 18 | count--; |
| 19 | if (!(*dest++ = *src++)) |
| 20 | { |
| 21 | goto finalize; |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | while (count >= sizeof (unsigned long)) |
| 26 | { |
| 27 | unsigned long value = *(unsigned long*)src; |
| 28 | unsigned long magic; |
| 29 | |
| 30 | if ((magic = (value - lomagic) & himagic)) |
| 31 | { |
| 32 | if (magic & ~value) |
| 33 | { |
| 34 | break; |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | *(unsigned long*)dest = value; |
| 39 | dest += sizeof (unsigned long); |
| 40 | src += sizeof (unsigned long); |
| 41 | count -= sizeof (unsigned long); |
| 42 | } |
| 43 | |
| 44 | while (count) |
| 45 | { |
| 46 | count--; |
| 47 | if (!(*dest++ = *src++)) |
| 48 | break; |
| 49 | } |
| 50 | |
| 51 | finalize: |
| 52 | if (count) |
| 53 | { |
| 54 | memset(dest, '\0', count); |
| 55 | } |
| 56 | |
| 57 | return ret; |
| 58 | } |
| 59 | libc_hidden_def(strncpy) |