1  /* Test of reopening a stream.
       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 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  /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
      18  
      19  #include <config.h>
      20  
      21  /* Specification.  */
      22  #include "stdio--.h"
      23  
      24  /* Helpers.  */
      25  #include <unistd.h>
      26  
      27  /* This test intentionally closes stderr.  So, we arrange to have fd 10
      28     (outside the range of interesting fd's during the test) set up to
      29     duplicate the original stderr.  */
      30  
      31  #define BACKUP_STDERR_FILENO 10
      32  #define ASSERT_STREAM myerr
      33  #include "macros.h"
      34  
      35  static FILE *myerr;
      36  
      37  int
      38  main (void)
      39  {
      40    FILE *fp;
      41  
      42    /* We close fd 2 later, so save it in fd 10.  */
      43    if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
      44        || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
      45      return 2;
      46  
      47    {
      48      FILE *tmp;
      49      ASSERT (tmp = fopen ("/dev/null", "r"));
      50      ASSERT (STDERR_FILENO < fileno (tmp));
      51      ASSERT (fp = fopen ("/dev/null", "w"));
      52      ASSERT (fileno (tmp) < fileno (fp));
      53      ASSERT (fclose (tmp) == 0);
      54    }
      55  
      56    /* Gap in fds.  */
      57    ASSERT (freopen ("/dev/null", "r+", fp) == fp);
      58    ASSERT (STDERR_FILENO < fileno (fp));
      59  
      60    ASSERT (freopen ("/dev/null", "r", stdin) == stdin);
      61    ASSERT (STDIN_FILENO == fileno (stdin));
      62  
      63    ASSERT (freopen ("/dev/null", "w", stdout) == stdout);
      64    ASSERT (STDOUT_FILENO == fileno (stdout));
      65  
      66    ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
      67    ASSERT (STDERR_FILENO == fileno (stderr));
      68  
      69    /* fd 0 closed.  */
      70    ASSERT (close (STDIN_FILENO) == 0);
      71  
      72    ASSERT (freopen ("/dev/null", "w", stdout) == stdout);
      73    ASSERT (STDOUT_FILENO == fileno (stdout));
      74  
      75    ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
      76    ASSERT (STDERR_FILENO == fileno (stderr));
      77  
      78    ASSERT (freopen ("/dev/null", "a", fp) == fp);
      79    ASSERT (STDERR_FILENO < fileno (fp));
      80  
      81    /* fd 1 closed.  */
      82    ASSERT (close (STDOUT_FILENO) == 0);
      83  
      84    ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
      85    ASSERT (STDERR_FILENO == fileno (stderr));
      86  
      87    ASSERT (freopen ("/dev/null", "a+", fp) == fp);
      88    ASSERT (STDERR_FILENO < fileno (fp));
      89  
      90    /* fd 2 closed.  */
      91    ASSERT (close (STDERR_FILENO) == 0);
      92  
      93    ASSERT (freopen ("/dev/null", "w+", fp) == fp);
      94    ASSERT (STDERR_FILENO < fileno (fp));
      95  
      96    return 0;
      97  }