Example 6. Obtaining File and Image Attributes

This example illustrates the use of the routines GRattrinfo/mgatinf,
GRfindattr/mgfndat, and GRgetattr/mggnatt/mggcatt
to extract information and values of file and image attributes that
were set by the program in Example 5.

In this example, the program gets the information about each file attribute,
then extracts its values.  The program then selects the second image in the
file, finds the attribute named "Image Attribute 2", obtains the data
type and the number of values in the attribute, and extracts its stored
values.