HDF_DFAN_GETDESC

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

The HDF_DFAN_GETDESC procedure reads the description for the given tag and reference number in an HDF file.

Syntax

HDF_DFAN_GETDESC, Filename, Tag, Ref, Description [, /STRING]

Arguments

Filename

A scalar string containing the name of the file to be read.

Tag

The tag number.

Reference

The reference number.

Description

A named variable in which the description is returned as a vector of bytes.

If a description does not exist, the Description variable will contain either a 0L (long-integer zero) or a blank string, and a warning message will be printed. Warning messages can be suppressed by setting the !QUIET system variable to a non-zero value.

Keywords

STRING

Set this keyword to return the description as a string rather than a vector of bytes.

Examples

desc1 = 'FILE DESCRIPTION NUMBER 1' 
tag_image = 302 
file = 'DEMOdesc.hdf' 
fid = HDF_OPEN(file, /CREATE) 
HDF_DFR8_ADDIMAGE, file, DIST(10) 
HDF_DFAN_PUTDESC, file, tag_image, HDF_DFR8_LASTREF(), desc1 
; Read the description and return a vector of bytes: 
HDF_DFAN_GETDESC, file, tag_image, HDF_DFR8_LASTREF(), out_desc1 
HELP, out_desc1 
PRINT, STRING(out_desc1) 
; Read the description and return an IDL string variable: 
HDF_DFAN_GETDESC, file, tag_image, HDF_DFR8_LASTREF(), $ 
    out_desc2, /STRING 
HELP, out_desc2 
HDF_CLOSE, fid 

IDL Output

OUT_DESC1       BYTE      = Array(25) 
 
FILE DESCRIPTION NUMBER 1 
 
OUT_DESC2       STRING    = 'FILE DESCRIPTION NUMBER 1' 

Version History

See Also

HDF_DFAN_PUTDESC