1  /* Test isatty() function.
       2     Copyright (C) 2011-2023 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 of the License, or
       7     (at your option) 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 (isatty, int, (int));
      23  
      24  #include <errno.h>
      25  #include <fcntl.h>
      26  
      27  #include "macros.h"
      28  
      29  /* The name of the "always silent" device.  */
      30  #if defined _WIN32 && ! defined __CYGWIN__
      31  /* Native Windows API.  */
      32  # define DEV_NULL "NUL"
      33  #else
      34  /* Unix API.  */
      35  # define DEV_NULL "/dev/null"
      36  #endif
      37  
      38  int
      39  main (void)
      40  {
      41    const char *file = "test-isatty.txt";
      42  
      43    /* Test behaviour for invalid file descriptors.  */
      44    {
      45      errno = 0;
      46      ASSERT (isatty (-1) == 0);
      47      ASSERT (errno == EBADF
      48              || errno == 0 /* seen on IRIX 6.5, Solaris 10 */
      49             );
      50    }
      51    {
      52      close (99);
      53      errno = 0;
      54      ASSERT (isatty (99) == 0);
      55      ASSERT (errno == EBADF
      56              || errno == 0 /* seen on IRIX 6.5, Solaris 10 */
      57             );
      58    }
      59  
      60    /* Test behaviour for regular files.  */
      61    {
      62      int fd;
      63  
      64      fd = open (file, O_WRONLY|O_CREAT|O_TRUNC, 0644);
      65      ASSERT (0 <= fd);
      66      ASSERT (write (fd, "hello", 5) == 5);
      67      ASSERT (close (fd) == 0);
      68  
      69      fd = open (file, O_RDONLY);
      70      ASSERT (0 <= fd);
      71      ASSERT (! isatty (fd));
      72      ASSERT (close (fd) == 0);
      73    }
      74  
      75    /* Test behaviour for pipes.  */
      76    {
      77      int fd[2];
      78  
      79      ASSERT (pipe (fd) == 0);
      80      ASSERT (! isatty (fd[0]));
      81      ASSERT (! isatty (fd[1]));
      82      ASSERT (close (fd[0]) == 0);
      83      ASSERT (close (fd[1]) == 0);
      84    }
      85  
      86    /* Test behaviour for /dev/null.  */
      87    {
      88      int fd;
      89  
      90      fd = open (DEV_NULL, O_RDONLY);
      91      ASSERT (0 <= fd);
      92      ASSERT (! isatty (fd));
      93      ASSERT (close (fd) == 0);
      94    }
      95  
      96    ASSERT (unlink (file) == 0);
      97  
      98    return 0;
      99  }