strncasecmp.c revision 1.1.1.1 
1/* strncase.c -- compare at most N characters of two strings without
2		 taking care for the case
3Copyright (C) 1992 Free Software Foundation.
4
5This program is free software; you can redistribute it and/or modify
6it under the terms of the GNU General Public License as published by
7the Free Software Foundation; either version 2, or (at your option)
8any later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; if not, write to the Free Software
17Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18
19#include <string.h>
20#include <ctype.h>
21
22/* Compare no more than N characters of S1 and S2,
23   ignoring case, returning less than, equal to or
24   greater than zero if S1 is lexicographically less
25   than, equal to or greater than S2.  */
26int
27strncasecmp (s1, s2, n)
28     const char *s1;
29     const char *s2;
30     size_t n;
31{
32  register const unsigned char *p1 = (const unsigned char *) s1;
33  register const unsigned char *p2 = (const unsigned char *) s2;
34  unsigned char c1, c2;
35
36  if (p1 == p2 || n == 0)
37    return 0;
38
39  do
40    {
41      c1 = tolower (*p1++);
42      c2 = tolower (*p2++);
43      if (c1 == '\0' || c1 != c2)
44	return c1 - c2;
45    } while (--n > 0);
46
47  return c1 - c2;
48}
49