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99 lines
2.5 KiB
C
99 lines
2.5 KiB
C
/* Case-insensitive string comparison function.
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Copyright (C) 1998, 1999, 2005 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2005,
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based on earlier glibc code.
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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 2, or (at your option)
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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, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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/* Specification. */
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#include "strcase.h"
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#include <ctype.h>
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#if HAVE_MBRTOWC
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# include "mbuiter.h"
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#endif
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#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
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/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
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greater than zero if S1 is lexicographically less than, equal to or greater
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than S2.
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Note: This function may, in multibyte locales, return 0 for strings of
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different lengths! */
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int
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strcasecmp (const char *s1, const char *s2)
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{
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if (s1 == s2)
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return 0;
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/* Be careful not to look at the entire extent of s1 or s2 until needed.
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This is useful because when two strings differ, the difference is
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most often already in the very few first characters. */
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#if HAVE_MBRTOWC
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if (MB_CUR_MAX > 1)
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{
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mbui_iterator_t iter1;
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mbui_iterator_t iter2;
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mbui_init (iter1, s1);
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mbui_init (iter2, s2);
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while (mbui_avail (iter1) && mbui_avail (iter2))
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{
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int cmp = mb_casecmp (mbui_cur (iter1), mbui_cur (iter2));
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if (cmp != 0)
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return cmp;
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mbui_advance (iter1);
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mbui_advance (iter2);
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}
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if (mbui_avail (iter1))
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/* s2 terminated before s1. */
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return 1;
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if (mbui_avail (iter2))
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/* s1 terminated before s2. */
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return -1;
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return 0;
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}
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else
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#endif
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{
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const unsigned char *p1 = (const unsigned char *) s1;
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const unsigned char *p2 = (const unsigned char *) s2;
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unsigned char c1, c2;
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do
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{
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c1 = TOLOWER (*p1);
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c2 = TOLOWER (*p2);
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if (c1 == '\0')
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break;
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++p1;
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++p2;
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}
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while (c1 == c2);
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return c1 - c2;
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}
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}
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