usr/src/lib/libc/port/stdio/rewind.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include "lint.h"
  33 #include "file64.h"
  34 #include "mtlib.h"
  35 #include <sys/types.h>
  36 #include <stdio.h>
  37 #include <unistd.h>
  38 #include <synch.h>
  39 #include <thread.h>
  40 #include "stdiom.h"
  41 #include "libc.h"
  42
  43
  44 void
  45 rewind(FILE *iop)
  46 {
  47         rmutex_t *lk;
  48
  49         FLOCKFILE(lk, iop);
  50         _rewind_unlocked(iop);
  51         FUNLOCKFILE(lk);
  52 }
  53
  54 void
  55 _rewind_unlocked(FILE *iop)
  56 {
  57         (void) _fflush_u(iop);
  58         (void) lseek64(FILENO(iop), 0, SEEK_SET);
  59         iop->_cnt = 0;
  60         iop->_ptr = iop->_base;
  61         iop->_flag &= ~(_IOERR | _IOEOF);
  62         if (iop->_flag & _IORW)
  63                 iop->_flag &= ~(_IOREAD | _IOWRT);
  64 }