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https://sourceware.org/git/glibc.git
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85 lines
1.8 KiB
C
85 lines
1.8 KiB
C
/* Copyright (C) 1993-2013 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* This is almost copied from strncpy.c, written by Torbjorn Granlund. */
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#include <string.h>
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/* Copy no more than N characters of SRC to DEST, returning the address of
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the terminating '\0' in DEST, if any, or else DEST + N. */
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char *
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__stpncpy_chk (char *dest, const char *src, size_t n, size_t destlen)
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{
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char c;
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char *s = dest;
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if (__builtin_expect (destlen < n, 0))
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__chk_fail ();
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if (n >= 4)
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{
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size_t n4 = n >> 2;
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for (;;)
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{
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c = *src++;
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*dest++ = c;
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if (c == '\0')
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break;
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c = *src++;
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*dest++ = c;
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if (c == '\0')
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break;
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c = *src++;
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*dest++ = c;
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if (c == '\0')
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break;
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c = *src++;
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*dest++ = c;
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if (c == '\0')
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break;
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if (--n4 == 0)
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goto last_chars;
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}
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n -= dest - s;
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goto zero_fill;
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}
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last_chars:
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n &= 3;
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if (n == 0)
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return dest;
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for (;;)
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{
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c = *src++;
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--n;
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*dest++ = c;
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if (c == '\0')
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break;
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if (n == 0)
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return dest;
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}
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zero_fill:
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while (n-- > 0)
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dest[n] = '\0';
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return dest - 1;
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}
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