1  /* Test of fread() function.
       2     Copyright (C) 2011-2022 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  #include <config.h>
      18  
      19  #include <stdio.h>
      20  
      21  #include "signature.h"
      22  SIGNATURE_CHECK (fread, size_t, (void *, size_t, size_t, FILE *));
      23  
      24  #include <errno.h>
      25  #include <fcntl.h>
      26  #include <unistd.h>
      27  
      28  #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
      29  # include "msvc-inval.h"
      30  #endif
      31  
      32  #include "macros.h"
      33  
      34  int
      35  main (int argc, char **argv)
      36  {
      37    const char *filename = "test-fread.txt";
      38  
      39    /* We don't have an fread() function that installs an invalid parameter
      40       handler so far.  So install that handler here, explicitly.  */
      41  #if HAVE_MSVC_INVALID_PARAMETER_HANDLER \
      42      && MSVC_INVALID_PARAMETER_HANDLING == DEFAULT_HANDLING
      43    gl_msvc_inval_ensure_handler ();
      44  #endif
      45  
      46    /* Prepare a file.  */
      47    {
      48      const char text[] = "hello world";
      49      int fd = open (filename, O_RDWR | O_CREAT | O_TRUNC, 0600);
      50      ASSERT (fd >= 0);
      51      ASSERT (write (fd, text, sizeof (text)) == sizeof (text));
      52      ASSERT (close (fd) == 0);
      53    }
      54  
      55    /* Test that fread() sets errno if someone else closes the stream
      56       fd behind the back of stdio.  */
      57    {
      58      FILE *fp = fopen (filename, "r");
      59      char buf[5];
      60      ASSERT (fp != NULL);
      61      ASSERT (close (fileno (fp)) == 0);
      62      errno = 0;
      63      ASSERT (fread (buf, 1, sizeof (buf), fp) == 0);
      64      ASSERT (errno == EBADF);
      65      ASSERT (ferror (fp));
      66      fclose (fp);
      67    }
      68  
      69    /* Test that fread() sets errno if the stream was constructed with
      70       an invalid file descriptor.  */
      71    {
      72      FILE *fp = fdopen (-1, "r");
      73      if (fp != NULL)
      74        {
      75          char buf[1];
      76          errno = 0;
      77          ASSERT (fread (buf, 1, 1, fp) == 0);
      78          ASSERT (errno == EBADF);
      79          ASSERT (ferror (fp));
      80          fclose (fp);
      81        }
      82    }
      83    {
      84      FILE *fp;
      85      close (99);
      86      fp = fdopen (99, "r");
      87      if (fp != NULL)
      88        {
      89          char buf[1];
      90          errno = 0;
      91          ASSERT (fread (buf, 1, 1, fp) == 0);
      92          ASSERT (errno == EBADF);
      93          ASSERT (ferror (fp));
      94          fclose (fp);
      95        }
      96    }
      97  
      98    /* Clean up.  */
      99    unlink (filename);
     100  
     101    return 0;
     102  }