ascii.c

/**
 * Copyright (C) 2001 Thomas Roessler <roessler@does-not-exist.org>
 *
 * 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 of the License, 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, see <http://www.gnu.org/licenses/>.
 */


/*
 * Versions of the string comparison functions which are
 * locale-insensitive.
 */

#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include "ascii.h"

int ascii_strcasecmp(const char *a, const char *b)
{
  int i;

  if (a == b)
    return 0;
  if (a == NULL && b)
    return -1;
  if (b == NULL && a)
    return 1;

  for (;; a++, b++)
  {
    if ((i = tolower(*a) - tolower(*b)))
      return i;
    /* test for NUL here rather that in the for loop in order to detect unequal
     * length strings (see http://dev.mutt.org/trac/ticket/3601)
     */
    if (!*a)
      break;
  }

  return 0;
}

int ascii_strncasecmp(const char *a, const char *b, int n)
{
  int i, j;

  if (a == b)
    return 0;
  if (a == NULL && b)
    return -1;
  if (b == NULL && a)
    return 1;

  for (j = 0; (*a || *b) && j < n; a++, b++, j++)
  {
    if ((i = tolower(*a) - tolower(*b)))
      return i;
  }

  return 0;
}