/* ifconfig.c -- network interface configuration utility   Copyright (C) 2001, 2002 Free Software Foundation, Inc.   Written by Marcus Brinkmann.   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   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 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. */#ifdef HAVE_CONFIG_H#include <config.h>#endif#include <sys/stat.h>#include <stdio.h>#include <errno.h>#if HAVE_UNISTD_H#include <unistd.h>#endif#if HAVE_STRING_H# include <string.h>#else# include <strings.h>#endif#if STDC_HEADERS# include <stdlib.h>#else# ifndef HAVE_STRCHR#  define strchr index#  define strrchr rindex# endif#endif#include <sys/types.h>#include <sys/socket.h>#include <sys/ioctl.h>#include <net/if.h>#include <arpa/inet.h>#include "ifconfig.h"intmain(int argc, char *argv[]){  int err = 0;  int sfd;  struct ifconfig *ifp;  parse_opt (argc, argv);  sfd = socket (AF_INET, SOCK_STREAM, 0);  if (sfd < 0)    {      fprintf (stderr, "%s: socket error: %s\n",		   program_name, strerror (errno));      exit (1);    }  ifp = ifs;  while (ifp - ifs < nifs)    {      err = configure_if (sfd, ifp);      if (err)	break;      ifp++;    }  close (sfd);  return (err);}