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Retrieves the metadata for an object specified by an identifier


herr_t H5Oget_info( hid_t object_id, H5O_info_t *object_info, unsigned int fields)
herr_t H5Oget_info( hid_t object_id, H5O_info_t *object_info )



H5O_GET_INFO is a macro that is mapped to:

Such macros are provided to facilitate application compatibility. Their use and mappings are fully described in API Compatibility Macros in HDF5; we urge you to read that document closely.

In HDF5 versions 1.12 and after, H5O_GET_INFO is mapped to H5O_GET_INFO3 and H5O_GET_INFO1 is deprecated. In version 1.10 H5O_GET_INFO is identical to H5O_GET_INFO1.

If using 1.10 (1.10.3+) and encountering performance issues, please use H5O_GET_INFO2 to limit the fields retrieved, which can help with performance.

Specific compile-time compatibility flags and the resulting mappings are as follows:

Compatibility settingH5Oget_info
No compatibility flag

H5O_GET_INFO3 (in release 1.12)

H5O_GET_INFO1 (in 1.8 or 1.10)

Emulate Release 1.12H5O_GET_INFO3
Emulate Release 1.10/1.8 interface H5O_GET_INFO1


If you are iterating through a lot of different objects to retrieve information via the H5O_GET_INFO family of routines, you may see memory building up. This can be due to memory allocation for metadata such as  object headers and messages when the iterated objects are put into the metadata cache.

If the memory buildup is not desirable, you can configure a smaller cache via H5F_SET_MDC_CONFIG or set the file access property list via H5P_SET_MDC_CONFIG. A smaller sized cache will force metadata entries to be evicted from the cache, thus freeing the memory associated with the entries.

Release    Change
1.12.0The macro H5O_GET_INFO and the function H5O_GET_INFO3 were added, and H5O_GET_INFO1 was deprecated.
1.10.5The macro H5O_GET_INFO was removed. The functions H5O_GET_INFO1 and H5O_GET_INFO are identical in this release. This change was added to restore the broken API compatibility introduced in HDF5-1.10.3.

The function H5O_GET_INFO was renamed H5O_GET_INFO1. The macro H5O_GET_INFO and the function H5O_GET_INFO2 were introduced in this release.

1.8.15Added a note about the valid values for the version field in the H5O_hdr_info_t structure.
1.8.11Fortran subroutine introduced in this release.
1.8.10Added H5O_type_t structure to the Description section.
Separated H5O_hdr_info_t structure from H5O_info_t in the Description section.
Clarified the definition and implementation of the time fields.
1.8.0Function introduced in this release.

--- Last Modified: March 22, 2021 | 02:33 PM