50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
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/* Case-insensitive buffer comparator.
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Copyright (C) 1996-1997, 2000, 2003, 2006, 2009-2020 Free Software
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Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program 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
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Jim Meyering. */
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#include <config.h>
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#include "memcasecmp.h"
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#include <ctype.h>
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#include <limits.h>
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/* Like memcmp, but ignore differences in case.
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Convert to upper case (not lower) before comparing so that
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join -i works with sort -f. */
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int
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memcasecmp (const void *vs1, const void *vs2, size_t n)
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{
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size_t i;
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char const *s1 = vs1;
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char const *s2 = vs2;
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for (i = 0; i < n; i++)
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{
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unsigned char u1 = s1[i];
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unsigned char u2 = s2[i];
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int U1 = toupper (u1);
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int U2 = toupper (u2);
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int diff = (UCHAR_MAX <= INT_MAX ? U1 - U2
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: U1 < U2 ? -1 : U2 < U1);
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if (diff)
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return diff;
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}
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return 0;
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}
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