104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
/* Case-insensitive string comparison function.
|
|
Copyright (C) 1998-1999, 2005-2006 Free Software Foundation, Inc.
|
|
Written by Bruno Haible <bruno@clisp.org>, 2005,
|
|
based on earlier glibc code.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software Foundation,
|
|
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
|
|
|
#include <config.h>
|
|
|
|
/* Specification. */
|
|
#include "strcase.h"
|
|
|
|
#include <ctype.h>
|
|
#include <limits.h>
|
|
|
|
#if HAVE_MBRTOWC
|
|
# include "mbuiter.h"
|
|
#endif
|
|
|
|
#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
|
|
|
|
/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
|
|
greater than zero if S1 is lexicographically less than, equal to or greater
|
|
than S2.
|
|
Note: This function may, in multibyte locales, return 0 for strings of
|
|
different lengths! */
|
|
int
|
|
strcasecmp (const char *s1, const char *s2)
|
|
{
|
|
if (s1 == s2)
|
|
return 0;
|
|
|
|
/* Be careful not to look at the entire extent of s1 or s2 until needed.
|
|
This is useful because when two strings differ, the difference is
|
|
most often already in the very few first characters. */
|
|
#if HAVE_MBRTOWC
|
|
if (MB_CUR_MAX > 1)
|
|
{
|
|
mbui_iterator_t iter1;
|
|
mbui_iterator_t iter2;
|
|
|
|
mbui_init (iter1, s1);
|
|
mbui_init (iter2, s2);
|
|
|
|
while (mbui_avail (iter1) && mbui_avail (iter2))
|
|
{
|
|
int cmp = mb_casecmp (mbui_cur (iter1), mbui_cur (iter2));
|
|
|
|
if (cmp != 0)
|
|
return cmp;
|
|
|
|
mbui_advance (iter1);
|
|
mbui_advance (iter2);
|
|
}
|
|
if (mbui_avail (iter1))
|
|
/* s2 terminated before s1. */
|
|
return 1;
|
|
if (mbui_avail (iter2))
|
|
/* s1 terminated before s2. */
|
|
return -1;
|
|
return 0;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
const unsigned char *p1 = (const unsigned char *) s1;
|
|
const unsigned char *p2 = (const unsigned char *) s2;
|
|
unsigned char c1, c2;
|
|
|
|
do
|
|
{
|
|
c1 = TOLOWER (*p1);
|
|
c2 = TOLOWER (*p2);
|
|
|
|
if (c1 == '\0')
|
|
break;
|
|
|
|
++p1;
|
|
++p2;
|
|
}
|
|
while (c1 == c2);
|
|
|
|
if (UCHAR_MAX <= INT_MAX)
|
|
return c1 - c2;
|
|
else
|
|
/* On machines where 'char' and 'int' are types of the same size, the
|
|
difference of two 'unsigned char' values - including the sign bit -
|
|
doesn't fit in an 'int'. */
|
|
return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
|
|
}
|
|
}
|