forked from Imagelibrary/rtems
73f6236bc0
IO handlers scheme that was implemented originally just to support sockets. The file system IO switch is more general and works fine.
80 lines
1.3 KiB
C
80 lines
1.3 KiB
C
/*
|
|
* lseek() - POSIX 1003.1b 6.5.3 - Reposition Read/Write File Offset
|
|
*
|
|
* COPYRIGHT (c) 1989-1998.
|
|
* On-Line Applications Research Corporation (OAR).
|
|
* Copyright assigned to U.S. Government, 1994.
|
|
*
|
|
* 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.
|
|
*
|
|
* $Id$
|
|
*/
|
|
|
|
#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
|
|
|