| /* strncasecmp.c -- case insensitive string comparator |
| Copyright (C) 1998-1999, 2005-2007, 2009-2013 Free Software Foundation, Inc. |
| |
| 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 3, 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/>. */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include <string.h> |
| |
| #include <ctype.h> |
| #include <limits.h> |
| |
| #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch)) |
| |
| /* Compare no more than N bytes of strings 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. |
| Note: This function cannot work correctly in multibyte locales. */ |
| |
| int |
| strncasecmp (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 (--n == 0 || c1 == '\0') |
| break; |
| |
| ++p1; |
| ++p2; |
| } |
| while (c1 == c2); |
| |
| if (UCHAR_MAX <= INT_MAX) |
| return c1 - c2; |
| else |
| /* On machines where 'char' and 'int' are types of the same size, the |
| difference of two 'unsigned char' values - including the sign bit - |
| doesn't fit in an 'int'. */ |
| return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0); |
| } |