1  /* Test of pipe.
       2     Copyright (C) 2009-2023 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  
      26  #if defined _WIN32 && ! defined __CYGWIN__
      27  /* Get declarations of the native Windows API functions.  */
      28  # define WIN32_LEAN_AND_MEAN
      29  # include <windows.h>
      30  /* Get _get_osfhandle.  */
      31  # if GNULIB_MSVC_NOTHROW
      32  #  include "msvc-nothrow.h"
      33  # else
      34  #  include <io.h>
      35  # endif
      36  #endif
      37  
      38  #include "binary-io.h"
      39  #include "macros.h"
      40  
      41  /* Return true if FD is open.  */
      42  static bool
      43  is_open (int fd)
      44  {
      45  #if defined _WIN32 && ! defined __CYGWIN__
      46    /* On native Windows, the initial state of unassigned standard file
      47       descriptors is that they are open but point to an
      48       INVALID_HANDLE_VALUE, and there is no fcntl.  */
      49    return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
      50  #else
      51  # ifndef F_GETFL
      52  #  error Please port fcntl to your platform
      53  # endif
      54    return 0 <= fcntl (fd, F_GETFL);
      55  #endif
      56  }
      57  
      58  /* Return true if FD is not inherited to child processes.  */
      59  static bool
      60  is_cloexec (int fd)
      61  {
      62  #if defined _WIN32 && ! defined __CYGWIN__
      63    HANDLE h = (HANDLE) _get_osfhandle (fd);
      64    DWORD flags;
      65    ASSERT (GetHandleInformation (h, &flags));
      66    return (flags & HANDLE_FLAG_INHERIT) == 0;
      67  #else
      68    int flags;
      69    ASSERT ((flags = fcntl (fd, F_GETFD)) >= 0);
      70    return (flags & FD_CLOEXEC) != 0;
      71  #endif
      72  }
      73  
      74  /* Return true if FD is in non-blocking mode.  */
      75  static bool
      76  is_nonblocking (int fd)
      77  {
      78  #if defined _WIN32 && ! defined __CYGWIN__
      79    /* We don't use the non-blocking mode for sockets here.  */
      80    return 0;
      81  #else
      82    int flags;
      83    ASSERT ((flags = fcntl (fd, F_GETFL)) >= 0);
      84    return (flags & O_NONBLOCK) != 0;
      85  #endif
      86  }
      87  
      88  int
      89  main ()
      90  {
      91    int fd[2];
      92  
      93    fd[0] = -1;
      94    fd[1] = -1;
      95    ASSERT (pipe (fd) >= 0);
      96    ASSERT (fd[0] >= 0);
      97    ASSERT (fd[1] >= 0);
      98    ASSERT (fd[0] != fd[1]);
      99    ASSERT (is_open (fd[0]));
     100    ASSERT (is_open (fd[1]));
     101    ASSERT (!is_cloexec (fd[0]));
     102    ASSERT (!is_cloexec (fd[1]));
     103    ASSERT (!is_nonblocking (fd[0]));
     104    ASSERT (!is_nonblocking (fd[1]));
     105  
     106    return 0;
     107  }