HDF_SD_ATTRFIND

Syntax | Arguments | Keywords | Examples | Version History | See Also

The HDF_SD_ATTRFIND function locates the index of an HDF attribute given its name. The attribute can be global or from a specific dataset. If an attribute is located, its index is returned. Otherwise, -1 is returned. Once an attribute's index is known, the HDF_SD_ATTRINFO function can be used to read that attribute.

Syntax

Result = HDF_SD_ATTRFIND(SD_id, Name)

Arguments

SD_id

An SD interface ID as returned by HDF_SD_START (i.e., a global attribute's "SDinterface_id"), or HDF_SD_SELECT/HDF_SD_CREATE (i.e., a dataset's "SDdataset_id").

Name

A string containing the name of the attribute whose index is to be returned.

Keywords

None

Examples

; Open an HDF file and start the SD interface: 
SDinterface_id = HDF_SD_START('demo.hdf') 
; Find "TITLE", a global attribute: 
gindex = HDF_SD_ATTRFIND(SDinterface_id, 'TITLE') 
; Get the ID for the first dataset: 
SDdataset_id = HDF_SD_SELECT(SDinterface_id, 1) 
; Read attribute info: 
HDF_SD_ATTRINFO,SDinterface_id,gindex, NAME=name, TYPE=type, 
COUNT=count 
; Print info about the returned variables: 
HELP, type, count, name 
; Find the "LOCATION" dataset attribute: 
dindex = HDF_SD_ATTRFIND(SDdataset_id, 'LOCATION') 
; Read attribute info: 
HDF_SD_ATTRINFO,SDdataset_id,dindex,NAME=name,TYPE=type,COUNT=count 

IDL Output

TYPE STRING = 'STRING' 
COUNT LONG = 8 
NAME STRING = 'TITLE' 

Version History

See Also

HDF_SD_ATTRINFO, HDF_SD_ATTRSET, HDF_SD_SELECT