1  /* Test of ftello() function.
       2     Copyright (C) 2011-2021 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 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 <stdio.h>
      20  
      21  #include <errno.h>
      22  #include <unistd.h>
      23  
      24  #include "macros.h"
      25  
      26  int
      27  main (int argc, char **argv)
      28  {
      29    const char *filename = argv[1];
      30  
      31    /* Test that ftello() sets errno if someone else closes the stream
      32       fd behind the back of stdio.  */
      33    {
      34      FILE *fp = fopen (filename, "r");
      35      ASSERT (fp != NULL);
      36      setvbuf (fp, NULL, _IONBF, 0);
      37      ASSERT (close (fileno (fp)) == 0);
      38      errno = 0;
      39      ASSERT (ftello (fp) == (off_t)-1);
      40      ASSERT (errno == EBADF);
      41      fclose (fp);
      42    }
      43  
      44    /* Test that ftello() sets errno if the stream was constructed with
      45       an invalid file descriptor.  */
      46    {
      47      FILE *fp = fdopen (-1, "w");
      48      if (fp != NULL)
      49        {
      50          errno = 0;
      51          ASSERT (ftello (fp) == (off_t)-1);
      52          ASSERT (errno == EBADF);
      53          fclose (fp);
      54        }
      55    }
      56    {
      57      FILE *fp;
      58      close (99);
      59      fp = fdopen (99, "w");
      60      if (fp != NULL)
      61        {
      62          errno = 0;
      63          ASSERT (ftello (fp) == (off_t)-1);
      64          ASSERT (errno == EBADF);
      65          fclose (fp);
      66        }
      67    }
      68  
      69    return 0;
      70  }