In the area of strcoll/memcoll and its generalization to Unicode strings, the
following generalization of memcmp is useful. I'm adding it as a new module.
2009-03-07 Bruno Haible <br...@clisp.org>
New module 'memcmp2'.
* lib/memcmp2.h: New file.
* lib/memcmp2.c: New file.
* modules/memcmp2: New file.
================================ lib/memcmp2.h ================================
/* Compare two memory areas with possibly different lengths.
Copyright (C) 2009 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 3 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef MEMCMP2_H
#define MEMCMP2_H
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/* Compare the memory regions S1 = [s1..s1+N1-1], S2 = [s2..s2+n2-1],
alphabetically.
This function's result is locale independent, unlike memcoll()'s.
Return a negative number if S1 < S2, a positive number if S1 > S2, or
0 if S1 and S2 have the same contents. */
extern int memcmp2 (const char *s1, size_t n1, const char *s2, size_t n2);
#ifdef __cplusplus
}
#endif
#endif /* MEMCMP2_H */
================================ lib/memcmp2.c ================================
/* Compare two memory areas with possibly different lengths.
Copyright (C) 2009 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 3 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include "memcmp2.h"
#include <string.h>
int
memcmp2 (const char *s1, size_t n1, const char *s2, size_t n2)
{
int cmp = memcmp (s1, s2, n1 <= n2 ? n1 : n2);
if (cmp == 0)
{
if (n1 < n2)
cmp = -1;
else if (n1 > n2)
cmp = 1;
}
return cmp;
}
=============================== modules/memcmp2 ===============================
Description:
Compare two memory areas with possibly different lengths.
Files:
lib/memcmp2.h
lib/memcmp2.c
Depends-on:
configure.ac:
Makefile.am:
lib_SOURCES += memcmp2.c
Include:
"memcmp2.h"
License:
LGPL
Maintainer:
Bruno Haible
