看看大家linux的能力！__the_NULL_exit_break_no_argument_

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看看大家linux的能力！

来源: 互联网发布时间：2016-05-12

/*下面给出的代码是GNU写的hello的小程序！看看那位高手能把它编译并运行！
当然最好给出详细的过程！能把hello写到如此份上，真是学到了很多！
*/
/* hello.c -- print a greeting message and exit.

   Copyright (C) 1992, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
   2005, 2006 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 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include
#include "system.h"

/* String containing name the program is called with.  */
const char *program_name;

static const struct option longopts[] =
{
  { "greeting", required_argument, NULL, 'g' },
  { "help", no_argument, NULL, 'h' },
  { "next-generation", no_argument, NULL, 'n' },
  { "traditional", no_argument, NULL, 't' },
  { "version", no_argument, NULL, 'v' },
  { NULL, 0, NULL, 0 }
};

static void print_help (void);
static void print_version (void);

int
main (int argc, char *argv[])
{
  int optc;
  int t = 0, n = 0, lose = 0;
  const char *greeting = NULL;

  program_name = argv[0];

  /* Set locale via LC_ALL.  */
  setlocale (LC_ALL, "";

#if ENABLE_NLS
  /* Set the text message domain.  */
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);
#endif

  /* Even exiting has subtleties.  The /dev/full device on GNU/Linux
     can be used for testing whether writes are checked properly.  For
     instance, hello >/dev/null should exit unsuccessfully.  On exit,
     if any writes failed, change the exit status.  This is
     implemented in the Gnulib module "closeout".  */
  atexit (close_stdout);

  while ((optc = getopt_long (argc, argv, "g:hntv", longopts, NULL)) != -1)
    switch (optc)
      {
      /* One goal here is having --help and --version exit immediately,
         per GNU coding standards.  */
      case 'v':
        print_version ();
        exit (EXIT_SUCCESS);
        break;
      case 'g':
        greeting = optarg;
        break;
      case 'h':
        print_help ();
        exit (EXIT_SUCCESS);
        break;
      case 'n':
        n = 1;
        break;
      case 't':
        t = 1;
        break;
      default:
        lose = 1;
        break;
      }

  if (lose || optind