coreutils/lib/memcoll.c

72 lines
1.9 KiB
C

/* Locale-specific memory comparison.
Copyright 1999 Free Software Foundation, Inc.
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Contributed by Paul Eggert <eggert@twinsun.com>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#if HAVE_STRING_H
# include <string.h>
#endif
/* Compare S1 (with length S1LEN) and S2 (with length S2LEN) according
to the LC_COLLATE locale. S1 and S2 do not overlap, and are not
adjacent. Temporarily modify the bytes after S1 and S2, but
restore their original contents before returning. */
int
memcoll (char *s1, size_t s1len, char *s2, size_t s2len)
{
int diff;
char n1 = s1[s1len];
char n2 = s2[s2len];
s1[s1len++] = '\0';
s2[s2len++] = '\0';
while (! (diff = strcoll (s1, s2)))
{
/* strcoll found no difference, but perhaps it was fooled by NUL
characters in the data. Work around this problem by advancing
past the NUL chars. */
size_t size1 = strlen (s1) + 1;
size_t size2 = strlen (s2) + 1;
s1 += size1;
s2 += size2;
s1len -= size1;
s2len -= size2;
if (s1len == 0)
{
if (s2len != 0)
diff = -1;
break;
}
else if (s2len == 0)
{
diff = 1;
break;
}
}
s1[s1len - 1] = n1;
s2[s2len - 1] = n2;
return diff;
}