/* Test of fclose module.
   Copyright (C) 2011-2022 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, see <https://www.gnu.org/licenses/>.  */

/* Written by Eric Blake.  */

#include <config.h>

#include <stdio.h>

#include "signature.h"
SIGNATURE_CHECK (fclose, int, (FILE *));

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "macros.h"

#define BASE "test-fclose.t"

int
main (int argc, char **argv)
{
  const char buf[] = "hello world";
  int fd;
  int fd2;
  FILE *f;

  /* Prepare a seekable file.  */
  fd = open (BASE, O_RDWR | O_CREAT | O_TRUNC, 0600);
  ASSERT (0 <= fd);
  ASSERT (write (fd, buf, sizeof buf) == sizeof buf);
  ASSERT (lseek (fd, 1, SEEK_SET) == 1);

  /* Create an output stream visiting the file; when it is closed, all
     other file descriptors visiting the file must see the new file
     position.  */
  fd2 = dup (fd);
  ASSERT (0 <= fd2);
  f = fdopen (fd2, "w");
  ASSERT (f);
  ASSERT (fputc (buf[1], f) == buf[1]);
  ASSERT (fclose (f) == 0);
  errno = 0;
  ASSERT (lseek (fd2, 0, SEEK_CUR) == -1);
  ASSERT (errno == EBADF);
  ASSERT (lseek (fd, 0, SEEK_CUR) == 2);

  /* Likewise for an input stream.  */
  fd2 = dup (fd);
  ASSERT (0 <= fd2);
  f = fdopen (fd2, "r");
  ASSERT (f);
  ASSERT (fgetc (f) == buf[2]);
  ASSERT (fclose (f) == 0);
  errno = 0;
  ASSERT (lseek (fd2, 0, SEEK_CUR) == -1);
  ASSERT (errno == EBADF);
  ASSERT (lseek (fd, 0, SEEK_CUR) == 3);

  /* Test that fclose() sets errno if someone else closes the stream
     fd behind the back of stdio.  */
  {
    FILE *fp = fdopen (fd, "w+");
    ASSERT (fp != NULL);
    ASSERT (close (fd) == 0);
    errno = 0;
    ASSERT (fclose (fp) == EOF);
    ASSERT (errno == EBADF);
  }

  /* Test that fclose() sets errno if the stream was constructed with
     an invalid file descriptor.  */
  {
    FILE *fp = fdopen (-1, "r");
    if (fp != NULL)
      {
        errno = 0;
        ASSERT (fclose (fp) == EOF);
        ASSERT (errno == EBADF);
      }
  }
  {
    FILE *fp;
    close (99);
    fp = fdopen (99, "r");
    if (fp != NULL)
      {
        errno = 0;
        ASSERT (fclose (fp) == EOF);
        ASSERT (errno == EBADF);
      }
  }

  /* Clean up.  */
  ASSERT (remove (BASE) == 0);

  return 0;
}