rewind.c   [plain text]

/* Copyright (C) 2002-2003 Free Software Foundation, Inc.
   Contributed by Andy Vaught

This file is part of the GNU Fortran 95 runtime library (libgfortran).

Libgfortran 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 2, or (at your option)
any later version.

Libgfortran 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 Libgfortran; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "libgfortran.h"
#include "io.h"

/* rewind.c--  Implement the rewind statement */

void
st_rewind (void)
{
  gfc_unit *u;

  library_start ();

  u = find_unit (ioparm.unit);
  if (u != NULL)
    {
      if (u->flags.access != ACCESS_SEQUENTIAL)
	generate_error (ERROR_BAD_OPTION,
			"Cannot REWIND a file opened for DIRECT access");
      else
	{
          if (g.mode==WRITING)
            struncate(u->s);
	  u->last_record = 0;
	  if (sseek (u->s, 0) == FAILURE)
	    generate_error (ERROR_OS, NULL);

	  u->endfile = NO_ENDFILE;
	  u->current_record = 0;
	  test_endfile (u);
	}
    }

  library_end ();
}