/* Test of ftell() function.

   Copyright (C) 2007-2020 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 of the License, 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/>.  */

#include <config.h>

/* None of the files accessed by this test are large, so disable the

   fseek link warning if we are not using the gnulib fseek module.  */

#define _GL_NO_LARGE_FILES

#include <stdio.h>

#include <string.h>

#include "macros.h"

#define TESTFILE "t-ftell3.tmp"

int

main (void)

{

  FILE *fp;

  /* Create a file with some contents.  */

  fp = fopen (TESTFILE, "w");

  if (fp == NULL)

    goto skip;

  if (fwrite ("foogarsh", 1, 8, fp) < 8)

    goto skip;

  if (fclose (fp))

    goto skip;

  /* The file's contents is now "foogarsh".  */

  /* Try writing after reading to EOF.  */

  fp = fopen (TESTFILE, "r+");

  if (fp == NULL)

    goto skip;

  if (fseek (fp, -1, SEEK_END))

    goto skip;

  ASSERT (getc (fp) == 'h');

  ASSERT (getc (fp) == EOF);

  ASSERT (ftell (fp) == 8);

  ASSERT (ftell (fp) == 8);

  ASSERT (putc ('!', fp) == '!');

  ASSERT (ftell (fp) == 9);

  ASSERT (fclose (fp) == 0);

  fp = fopen (TESTFILE, "r");

  if (fp == NULL)

    goto skip;

  {

    char buf[10];

    ASSERT (fread (buf, 1, 10, fp) == 9);

    ASSERT (memcmp (buf, "foogarsh!", 9) == 0);

  }

  ASSERT (fclose (fp) == 0);

  /* The file's contents is now "foogarsh!".  */

  remove (TESTFILE);

  return 0;

 skip:

  fprintf (stderr, "Skipping test: prerequisite file operations failed.\n");

  remove (TESTFILE);

  return 77;

}