new module 'memcmp2'

[Bruno Haible]

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  <address@hidden>

        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