coreutils/lib/memcasecmp.c
1997-10-27 04:59:25 +00:00

64 lines
1.8 KiB
C

/* Case-insensitive buffer comparator.
Copyright (C) 1996, 1997 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. */
/* Jim Meyering (meyering@na-net.ornl.gov) */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <ctype.h>
#if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
# define IN_CTYPE_DOMAIN(c) 1
#else
# define IN_CTYPE_DOMAIN(c) isascii(c)
#endif
#define ISLOWER(c) (IN_CTYPE_DOMAIN (c) && islower (c))
#if _LIBC || STDC_HEADERS
# define TOUPPER(c) toupper (c)
#else
# define TOUPPER(c) (ISLOWER (c) ? toupper (c) : (c))
#endif
#include "memcasecmp.h"
/* Like memcmp, but ignore differences in case.
Convert to upper case (not lower) before comparing so that
join -i works with sort -f. */
int
memcasecmp (vs1, vs2, n)
const void *vs1;
const void *vs2;
size_t n;
{
unsigned int i;
unsigned char *s1 = (unsigned char *) vs1;
unsigned char *s2 = (unsigned char *) vs2;
for (i = 0; i < n; i++)
{
unsigned char u1 = *s1++;
unsigned char u2 = *s2++;
if (TOUPPER (u1) != TOUPPER (u2))
return TOUPPER (u1) - TOUPPER (u2);
}
return 0;
}