/* netconn.c -- is a particular file descriptor a network connection?. *//* Copyright (C) 2002-2005 Free Software Foundation, Inc.   This file is part of GNU Bash, the Bourne Again SHell.   Bash 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 3 of the License, or   (at your option) any later version.   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.*/#include <config.h>#include <bashtypes.h>#if ! defined(_MINIX) && defined (HAVE_SYS_FILE_H)#  include <sys/file.h>#endif#include <posixstat.h>#include <filecntl.h>#include <errno.h>#if defined (HAVE_UNISTD_H)#  include <unistd.h>#endif/* The second and subsequent conditions must match those used to decide   whether or not to call getpeername() in isnetconn(). */#if defined (HAVE_SYS_SOCKET_H) && defined (HAVE_GETPEERNAME) && !defined (SVR4_2)#  include <sys/socket.h>#endif/* Is FD a socket or network connection? */intisnetconn (fd)     int fd;{#if defined (HAVE_GETPEERNAME) && !defined (SVR4_2) && !defined (__BEOS__)  int rv;  socklen_t l;  struct sockaddr sa;  l = sizeof(sa);  rv = getpeername(fd, &sa, &l);  /* Posix.2 says getpeername can return these errors. */  return ((rv < 0 && (errno == ENOTSOCK || errno == ENOTCONN || errno == EINVAL)) ? 0 : 1);#else /* !HAVE_GETPEERNAME || SVR4_2 || __BEOS__ */#  if defined (SVR4) || defined (SVR4_2)  /* Sockets on SVR4 and SVR4.2 are character special (streams) devices. */  struct stat sb;  if (isatty (fd))    return (0);  if (fstat (fd, &sb) < 0)    return (0);#    if defined (S_ISFIFO)  if (S_ISFIFO (sb.st_mode))    return (0);#    endif /* S_ISFIFO */  return (S_ISCHR (sb.st_mode));#  else /* !SVR4 && !SVR4_2 */#    if defined (S_ISSOCK) && !defined (__BEOS__)  struct stat sb;  if (fstat (fd, &sb) < 0)    return (0);  return (S_ISSOCK (sb.st_mode));#    else /* !S_ISSOCK || __BEOS__ */  return (0);#    endif /* !S_ISSOCK || __BEOS__ */#  endif /* !SVR4 && !SVR4_2 */#endif /* !HAVE_GETPEERNAME || SVR4_2 || __BEOS__ */}