| /* 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. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combine |
| executable.) |
| |
| 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 */ |
| |
| extern void st_rewind (void); |
| export_proto(st_rewind); |
| |
| 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 we have been writing to the file, the last written record |
| is the last record in the file, so truncate the file now. |
| Reset to read mode so two consecutive rewind statements |
| don't delete the file contents. Flush buffer when switching |
| mode. */ |
| if (u->mode == WRITING) |
| { |
| flush (u->s); |
| struncate (u->s); |
| } |
| u->mode = READING; |
| 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); |
| } |
| /* update position for INQUIRE */ |
| u->flags.position = POSITION_REWIND; |
| } |
| |
| library_end (); |
| } |