1  /* Test of fclose module.
       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, or (at your option)
       7     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.  */
      18  
      19  #include <config.h>
      20  
      21  #include <stdio.h>
      22  
      23  #include "signature.h"
      24  SIGNATURE_CHECK (fclose, int, (FILE *));
      25  
      26  #include <errno.h>
      27  #include <fcntl.h>
      28  #include <stdlib.h>
      29  #include <string.h>
      30  #include <unistd.h>
      31  
      32  #include "macros.h"
      33  
      34  #define BASE "test-fclose.t"
      35  
      36  int
      37  main (int argc, char **argv)
      38  {
      39    const char buf[] = "hello world";
      40    int fd;
      41    int fd2;
      42    FILE *f;
      43  
      44    /* Prepare a seekable file.  */
      45    fd = open (BASE, O_RDWR | O_CREAT | O_TRUNC, 0600);
      46    ASSERT (0 <= fd);
      47    ASSERT (write (fd, buf, sizeof buf) == sizeof buf);
      48    ASSERT (lseek (fd, 1, SEEK_SET) == 1);
      49  
      50    /* Create an output stream visiting the file; when it is closed, all
      51       other file descriptors visiting the file must see the new file
      52       position.  */
      53    fd2 = dup (fd);
      54    ASSERT (0 <= fd2);
      55    f = fdopen (fd2, "w");
      56    ASSERT (f);
      57    ASSERT (fputc (buf[1], f) == buf[1]);
      58    ASSERT (fclose (f) == 0);
      59    errno = 0;
      60    ASSERT (lseek (fd2, 0, SEEK_CUR) == -1);
      61    ASSERT (errno == EBADF);
      62    ASSERT (lseek (fd, 0, SEEK_CUR) == 2);
      63  
      64    /* Likewise for an input stream.  */
      65    fd2 = dup (fd);
      66    ASSERT (0 <= fd2);
      67    f = fdopen (fd2, "r");
      68    ASSERT (f);
      69    ASSERT (fgetc (f) == buf[2]);
      70    ASSERT (fclose (f) == 0);
      71    errno = 0;
      72    ASSERT (lseek (fd2, 0, SEEK_CUR) == -1);
      73    ASSERT (errno == EBADF);
      74    ASSERT (lseek (fd, 0, SEEK_CUR) == 3);
      75  
      76    /* Test that fclose() sets errno if someone else closes the stream
      77       fd behind the back of stdio.  */
      78    {
      79      FILE *fp = fdopen (fd, "w+");
      80      ASSERT (fp != NULL);
      81      ASSERT (close (fd) == 0);
      82      errno = 0;
      83      ASSERT (fclose (fp) == EOF);
      84      ASSERT (errno == EBADF);
      85    }
      86  
      87    /* Test that fclose() sets errno if the stream was constructed with
      88       an invalid file descriptor.  */
      89    {
      90      FILE *fp = fdopen (-1, "r");
      91      if (fp != NULL)
      92        {
      93          errno = 0;
      94          ASSERT (fclose (fp) == EOF);
      95          ASSERT (errno == EBADF);
      96        }
      97    }
      98    {
      99      FILE *fp;
     100      close (99);
     101      fp = fdopen (99, "r");
     102      if (fp != NULL)
     103        {
     104          errno = 0;
     105          ASSERT (fclose (fp) == EOF);
     106          ASSERT (errno == EBADF);
     107        }
     108    }
     109  
     110    /* Clean up.  */
     111    ASSERT (remove (BASE) == 0);
     112  
     113    return 0;
     114  }