contrib/diffutils-2.8/lib/posixver.c

   1 /* Which POSIX version to conform to, for utilities.
   2
   3    Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program; if not, write to the Free Software Foundation,
  17    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 /* Written by Paul Eggert.  */
  20
  21 #if HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include "posixver.h"
  26
  27 #include <limits.h>
  28 #include <stdlib.h>
  29
  30 #if HAVE_UNISTD_H
  31 # include <unistd.h>
  32 #endif
  33 #ifndef _POSIX2_VERSION
  34 # define _POSIX2_VERSION 0
  35 #endif
  36
  37 #ifndef DEFAULT_POSIX2_VERSION
  38 # define DEFAULT_POSIX2_VERSION _POSIX2_VERSION
  39 #endif
  40
  41 /* The POSIX version that utilities should conform to.  The default is
  42    specified by the system.  */
  43
  44 int
  45 posix2_version (void)
  46 {
  47   long int v = DEFAULT_POSIX2_VERSION;
  48   char const *s = getenv ("_POSIX2_VERSION");
  49
  50   if (s && *s)
  51     {
  52       char *e;
  53       long int i = strtol (s, &e, 10);
  54       if (! *e)
  55         v = i;
  56     }
  57
  58   return v < INT_MIN ? INT_MIN : v < INT_MAX ? v : INT_MAX;
  59 }