tests/test-isatty.c

   1 /* Test isatty() function.
   2    Copyright (C) 2011-2024 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 test_exit_status;
  99 }