SD Programming Model - Example

The following fragment of code is an example of what the function calls might look like when reading an HDF file in a program:

C:
	sd_id = SDstart (filename, DFACC_READ);
	sds_index = SDnametoindex (sd_id, "Data_Set_Name")  
	sds_id = SDselect (sd_id, sds_index);
                  .
                  .
                  .
	istat = SDendaccess (sds_id);
	istat = SDend (sd_id);

FORTRAN:
	sd_id = sfstart (filename, DFACC_READ)
	sds_index = sfn2index (sd_id, 'Data_Set_Name') 
	sds_id = sfselect (sd_id, sds_index)
                   .
                   .
                   .
	istat = sfendacc (sds_id)
	istat = sfend (sd_id)>

Following are the steps:

Open the file and start the SD index (SDstart/sfstart) giving it the name of the file to open, and the file access code you wish to open the file with.
Get the index of the SDS with the name "Data_Set_Name" (SDnametoindex/sfn2index).
Select the SDS with the specified index (SDselect/sfselect).
Terminate access to the data set array (SDendaccess/sfendacc).
Terminate access to the SD interface and close the file (SDend/sfend).