1  /* Test of fseeko() 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 fseeko() 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 (ftell (fp) == 0);
      38      ASSERT (fseeko (fp, 0, SEEK_END) == 0);
      39      ASSERT (ftell (fp) > 0);
      40      ASSERT (close (fileno (fp)) == 0);
      41      errno = 0;
      42      ASSERT (fseeko (fp, 0, SEEK_SET) == -1);
      43      ASSERT (errno == EBADF);
      44      fclose (fp);
      45    }
      46  
      47    /* Test that fseeko() sets errno if the stream was constructed with
      48       an invalid file descriptor.  */
      49    {
      50      FILE *fp = fdopen (-1, "w");
      51      if (fp != NULL)
      52        {
      53          errno = 0;
      54          ASSERT (fseeko (fp, 0, SEEK_END) == -1);
      55          ASSERT (errno == EBADF);
      56          fclose (fp);
      57        }
      58    }
      59    {
      60      FILE *fp;
      61      close (99);
      62      fp = fdopen (99, "w");
      63      if (fp != NULL)
      64        {
      65          errno = 0;
      66          ASSERT (fseeko (fp, 0, SEEK_END) == -1);
      67          ASSERT (errno == EBADF);
      68          fclose (fp);
      69        }
      70    }
      71  
      72    return 0;
      73  }