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path: root/gnu/usr.bin/texinfo/lib/strncasecmp.c
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/* strncase.c -- compare at most N characters of two strings without
		 taking care for the case
Copyright (C) 1992 Free Software Foundation.

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. */

#include <string.h>
#include <ctype.h>

/* Compare no more than N characters of 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.  */
int
strncasecmp (s1, s2, n)
     const char *s1;
     const char *s2;
     size_t n;
{
  register const unsigned char *p1 = (const unsigned char *) s1;
  register const unsigned char *p2 = (const unsigned char *) s2;
  unsigned char c1, c2;

  if (p1 == p2 || n == 0)
    return 0;

  do
    {
      c1 = tolower (*p1++);
      c2 = tolower (*p2++);
      if (c1 == '\0' || c1 != c2)
	return c1 - c2;
    } while (--n > 0);

  return c1 - c2;
}