posixver.c

来自「Linux下文件工具。」· C语言 代码 · 共 59 行

/* Which POSIX version to conform to, for utilities.

   Copyright (C) 2002 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU Library General Public License as published
   by the Free Software Foundation; either version 2, 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library 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.  */

/* Written by Paul Eggert.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#include <limits.h>

#include <stdlib.h>
#if !HAVE_DECL_GETENV && !defined getenv
char *getenv ();
#endif

#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifndef _POSIX2_VERSION
# define _POSIX2_VERSION 0
#endif

/* The POSIX version that utilities should conform to.  The default is
   specified by the system.  */

int
posix2_version (void)
{
  long int v = _POSIX2_VERSION;
  char const *s = getenv ("_POSIX2_VERSION");

  if (s && *s)
    {
      char *e;
      long int i = strtol (s, &e, 10);
      if (! *e)
	v = i;
    }

  return v < INT_MIN ? INT_MIN : v < INT_MAX ? v : INT_MAX;
}