1/*	$NetBSD: strcasecmp.c,v 1.1.1.1 2016/01/13 03:15:30 christos Exp $	*/
2
3/* strcasecmp.c -- case insensitive string comparator
4   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2, or (at your option)
9   any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software Foundation,
18   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
19
20#if HAVE_CONFIG_H
21# include <config.h>
22#endif
23
24#ifdef LENGTH_LIMIT
25# define STRXCASECMP_FUNCTION strncasecmp
26# define STRXCASECMP_DECLARE_N , size_t n
27# define LENGTH_LIMIT_EXPR(Expr) Expr
28#else
29# define STRXCASECMP_FUNCTION strcasecmp
30# define STRXCASECMP_DECLARE_N /* empty */
31# define LENGTH_LIMIT_EXPR(Expr) 0
32#endif
33
34#include <sys/types.h>
35#include <ctype.h>
36
37#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
38
39/* Compare {{no more than N characters of }}strings S1 and S2,
40   ignoring case, returning less than, equal to or
41   greater than zero if S1 is lexicographically less
42   than, equal to or greater than S2.  */
43
44int
45STRXCASECMP_FUNCTION (const char *s1, const char *s2 STRXCASECMP_DECLARE_N)
46{
47  register const unsigned char *p1 = (const unsigned char *) s1;
48  register const unsigned char *p2 = (const unsigned char *) s2;
49  unsigned char c1, c2;
50
51  if (p1 == p2 || LENGTH_LIMIT_EXPR (n == 0))
52    return 0;
53
54  do
55    {
56      c1 = TOLOWER (*p1);
57      c2 = TOLOWER (*p2);
58
59      if (LENGTH_LIMIT_EXPR (--n == 0) || c1 == '\0')
60	break;
61
62      ++p1;
63      ++p2;
64    }
65  while (c1 == c2);
66
67  return c1 - c2;
68}
69