/*
 * Copyright (C) 2008 Search Solution Corporation. All rights reserved by Search Solution.
 *
 *   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; version 2 of the License.
 *
 *  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
 *
 */

/*
 * misc_string.c : case insensitive string comparison routines for 8-bit
 *                 character sets
 */

#ident "$Id$"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "misc_string.h"

/*
 * ustr_casestr() - find a substring, case ignored
 *   return: char*
 *   s1(in)
 *   s2(in)
 */
char *
ustr_casestr (const char *s1, const char *s2)
{
  size_t len1, len2;
  const char *p1, *p2;
  int c;

  if (!s1 || !s2)
    return NULL;
  if (s1 == s2)
    return (char *) s1;
  if (!*s2)
    return (char *) s1;
  if (!*s1)
    return NULL;

  len1 = strlen (s1);
  len2 = strlen (s2);
  c = tolower (*s2);
  while (len1 >= len2)
    {
      while (tolower (*s1) != c)
	{
	  if (--len1 < len2)
	    return NULL;
	  s1++;
	}

      p1 = s1;
      p2 = s2;
      while (tolower (*p1) == tolower (*p2))
	{
	  p1++;
	  p2++;
	  if (!*p2)
	    return (char *) s1;
	}

      if (p1 == s1)
	{
	  len1--;
	  s1--;
	}
      else
	{
	  len1 -= (p1 - s1) + 1;
	  s1 += (p1 - s1) + 1;
	}
    }
  return NULL;
}

/*
 * ustr_upper() - replace all lower case characters with upper case characters
 *   return: char *
 *   s(in/out)
 */
char *
ustr_upper (char *s)
{
  char *t;

  if (!s)
    return NULL;

  for (t = s; *t; t++)
    *t = toupper (*t);
  return s;
}

/*
 * ustr_lower() - replace all upper case characters with lower case characters
 *   return: char *
 *   s(in/out)
 */
char *
ustr_lower (char *s)
{
  char *t;

  if (!s)
    return NULL;

  for (t = s; *t; t++)
    *t = tolower (*t);
  return s;
}