accessing low level file descriptor or handle

Hdf-forum archives
1

Hi All,

H5FOpen returns an opaque hid_t for the file. What if I need to get in
there and fiddle with the file properties via fcntl interface? Is there
any way for me to get access to the underlying stream or file
descriptor? At this point, I don't really care if its 'nice' and
portable and proper. I just need a way to get at it for standard VFD's
such as SEC2 or STDIO.

Mark

···

--
Mark C. Miller, Lawrence Livermore National Laboratory
================!!LLNL BUSINESS ONLY!!================
miller86@llnl.gov urgent: miller86@pager.llnl.gov
T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-8511

2

Mark,

There's an API function

    /herr_t /|H5Fget_vfd_handle|(/hid_t/ |file_id|, /hid_t/ |fapl_id|, /void **/|file_handle| )

for this purpose. You can find it in the v1.8 Reference Manual:

    http://www.hdfgroup.org/HDF5/doc/RM/RM_H5F.html#File-GetVfdHandle

Thanks.

Ray

Mark Miller wrote:

···

Hi All,

H5FOpen returns an opaque hid_t for the file. What if I need to get in
there and fiddle with the file properties via fcntl interface? Is there
any way for me to get access to the underlying stream or file
descriptor? At this point, I don't really care if its 'nice' and
portable and proper. I just need a way to get at it for standard VFD's
such as SEC2 or STDIO.

Mark

3

H5Fget_vfd_handle will do your trick but if you want to lock we can discuss this a bit as I recently finished that part

Happy new year to all!

Dimitris

Από το iPod μου

Jan 6, 2010, 11:08 PM, ο/η Mark Miller <miller86@llnl.gov> έγραψε:

···

Hi All,

H5FOpen returns an opaque hid_t for the file. What if I need to get in
there and fiddle with the file properties via fcntl interface? Is there
any way for me to get access to the underlying stream or file
descriptor? At this point, I don't really care if its 'nice' and
portable and proper. I just need a way to get at it for standard VFD's
such as SEC2 or STDIO.

Mark

--
Mark C. Miller, Lawrence Livermore National Laboratory
================!!LLNL BUSINESS ONLY!!================
miller86@llnl.gov urgent: miller86@pager.llnl.gov
T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-8511

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

4

Awsome! Thanks much. I guess I should have RTFM but I'm in a bit of a
crunch for time.

Mark

···

On Wed, 2010-01-06 at 16:21 -0600, Raymond Lu wrote:

Mark,

There's an API function

    /herr_t /|H5Fget_vfd_handle|(/hid_t/ |file_id|, /hid_t/ |fapl_id|,
/void **/|file_handle| )

for this purpose. You can find it in the v1.8 Reference Manual:

    http://*www.*hdfgroup.org/HDF5/doc/RM/RM_H5F.html#File-GetVfdHandle

Thanks.

Ray

Mark Miller wrote:
> Hi All,
>
> H5FOpen returns an opaque hid_t for the file. What if I need to get in
> there and fiddle with the file properties via fcntl interface? Is there
> any way for me to get access to the underlying stream or file
> descriptor? At this point, I don't really care if its 'nice' and
> portable and proper. I just need a way to get at it for standard VFD's
> such as SEC2 or STDIO.
>
> Mark
>
>

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://*mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

--
Mark C. Miller, Lawrence Livermore National Laboratory
================!!LLNL BUSINESS ONLY!!================
miller86@llnl.gov urgent: miller86@pager.llnl.gov
T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-8511

5

Από το iPod μου - It means From my iPod?

Ray

Dimitris Servis wrote:

···

H5Fget_vfd_handle will do your trick but if you want to lock we can discuss this a bit as I recently finished that part

Happy new year to all!

Dimitris

Από το iPod μου

Jan 6, 2010, 11:08 PM, ο/η Mark Miller <miller86@llnl.gov <mailto:miller86@llnl.gov>> έγραψε:

Hi All,

H5FOpen returns an opaque hid_t for the file. What if I need to get in
there and fiddle with the file properties via fcntl interface? Is there
any way for me to get access to the underlying stream or file
descriptor? At this point, I don't really care if its 'nice' and
portable and proper. I just need a way to get at it for standard VFD's
such as SEC2 or STDIO.

Mark

--
Mark C. Miller, Lawrence Livermore National Laboratory
================!!LLNL BUSINESS ONLY!!================
miller86@llnl.gov <mailto:miller86@llnl.gov> urgent: miller86@pager.llnl.gov <mailto:miller86@pager.llnl.gov>
T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-8511

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org <mailto:Hdf-forum@hdfgroup.org>
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

------------------------------------------------------------------------

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

6

Yes, sorry for that!

Jan 7, 2010, 12:25 AM, ο/η Raymond Lu <songyulu@hdfgroup.org> έγραψε:

···

Από το iPod μου - It means From my iPod?

Ray

Dimitris Servis wrote:

H5Fget_vfd_handle will do your trick but if you want to lock we can discuss this a bit as I recently finished that part

Happy new year to all!

Dimitris

Από το iPod μου

Jan 6, 2010, 11:08 PM, ο/η Mark Miller <miller86@llnl.gov <mailto:miller86@llnl.g>> έγραψε:

Hi All,

H5FOpen returns an opaque hid_t for the file. What if I need to get in
there and fiddle with the file properties via fcntl interface? Is there
any way for me to get access to the underlying stream or file
descriptor? At this point, I don't really care if its 'nice' and
portable and proper. I just need a way to get at it for standard VFD's
such as SEC2 or STDIO.

Mark

--
Mark C. Miller, Lawrence Livermore National Laboratory
================!!LLNL BUSINESS ONLY!!================
miller86@llnl.gov <mailto:miller86@llnl.gov> urgent: miller86@pager.llnl.gov <mailto:miller86@pager.llnl.gov>
T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-8511

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org <mailto:Hdf-forum@hdfgroup.org>
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

------------------------------------------------------------------------

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org