1  /* Test of pipe.
       2     Copyright (C) 2009-2021 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or modify
       5     it under the terms of the GNU General Public License as published by
       6     the Free Software Foundation; either version 3, or (at your option)
       7     any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program; if not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #include <config.h>
      18  
      19  #include <unistd.h>
      20  
      21  #include "signature.h"
      22  SIGNATURE_CHECK (pipe, int, (int[2]));
      23  
      24  #include <fcntl.h>
      25  #include <stdbool.h>
      26  
      27  #if defined _WIN32 && ! defined __CYGWIN__
      28  /* Get declarations of the native Windows API functions.  */
      29  # define WIN32_LEAN_AND_MEAN
      30  # include <windows.h>
      31  /* Get _get_osfhandle.  */
      32  # if GNULIB_MSVC_NOTHROW
      33  #  include "msvc-nothrow.h"
      34  # else
      35  #  include <io.h>
      36  # endif
      37  #endif
      38  
      39  #include "binary-io.h"
      40  #include "macros.h"
      41  
      42  /* Return true if FD is open.  */
      43  static bool
      44  is_open (int fd)
      45  {
      46  #if defined _WIN32 && ! defined __CYGWIN__
      47    /* On native Windows, the initial state of unassigned standard file
      48       descriptors is that they are open but point to an
      49       INVALID_HANDLE_VALUE, and there is no fcntl.  */
      50    return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
      51  #else
      52  # ifndef F_GETFL
      53  #  error Please port fcntl to your platform
      54  # endif
      55    return 0 <= fcntl (fd, F_GETFL);
      56  #endif
      57  }
      58  
      59  /* Return true if FD is not inherited to child processes.  */
      60  static bool
      61  is_cloexec (int fd)
      62  {
      63  #if defined _WIN32 && ! defined __CYGWIN__
      64    HANDLE h = (HANDLE) _get_osfhandle (fd);
      65    DWORD flags;
      66    ASSERT (GetHandleInformation (h, &flags));
      67    return (flags & HANDLE_FLAG_INHERIT) == 0;
      68  #else
      69    int flags;
      70    ASSERT ((flags = fcntl (fd, F_GETFD)) >= 0);
      71    return (flags & FD_CLOEXEC) != 0;
      72  #endif
      73  }
      74  
      75  /* Return true if FD is in non-blocking mode.  */
      76  static bool
      77  is_nonblocking (int fd)
      78  {
      79  #if defined _WIN32 && ! defined __CYGWIN__
      80    /* We don't use the non-blocking mode for sockets here.  */
      81    return 0;
      82  #else
      83    int flags;
      84    ASSERT ((flags = fcntl (fd, F_GETFL)) >= 0);
      85    return (flags & O_NONBLOCK) != 0;
      86  #endif
      87  }
      88  
      89  int
      90  main ()
      91  {
      92    int fd[2];
      93  
      94    fd[0] = -1;
      95    fd[1] = -1;
      96    ASSERT (pipe (fd) >= 0);
      97    ASSERT (fd[0] >= 0);
      98    ASSERT (fd[1] >= 0);
      99    ASSERT (fd[0] != fd[1]);
     100    ASSERT (is_open (fd[0]));
     101    ASSERT (is_open (fd[1]));
     102    ASSERT (!is_cloexec (fd[0]));
     103    ASSERT (!is_cloexec (fd[1]));
     104    ASSERT (!is_nonblocking (fd[0]));
     105    ASSERT (!is_nonblocking (fd[1]));
     106  
     107    return 0;
     108  }