Subversion Repositories openrisc_2011-10-31

/*

 *  lseek() - POSIX 1003.1b 6.5.3 - Reposition Read/Write File Offset

 *

 *  COPYRIGHT (c) 1989-1999.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: lseek.c,v 1.2 2001-09-27 12:01:15 chris Exp $

 */

#include <stdio.h>

#include "libio_.h"

off_t lseek(

  int     fd,

  off_t   offset,

  int     whence

)

{

  rtems_libio_t *iop;

  rtems_libio_check_fd( fd );

  iop = rtems_libio_iop( fd );

  rtems_libio_check_is_open(iop);

  /*

   *  Now process the lseek().

   */

  switch ( whence ) {

    case SEEK_SET:

      iop->offset = offset;

      break;

    case SEEK_CUR:

      iop->offset += offset;

      break;

    case SEEK_END:

      iop->offset = iop->size - offset;

      break;

    default:

      errno = EINVAL;

      return -1;

  }

  if ( !iop->handlers->lseek )

    set_errno_and_return_minus_one( ENOTSUP );

  return (*iop->handlers->lseek)( iop, offset, whence );

}

/*

 *  _lseek_r

 *

 *  This is the Newlib dependent reentrant version of lseek().

 */

#if defined(RTEMS_NEWLIB)

#include <reent.h>

off_t _lseek_r(

  struct _reent *ptr,

  int            fd,

  off_t          offset,

  int            whence

)

{

  return lseek( fd, offset, whence );

}

#endif