[obj]_id	IN:	Raster image identifier (ri_id), returned by GRcreate or GRselect, or GR interface identifier (gr_id), returned by GRstart
	attr_index	IN:	Index of the attribute
	name	OUT:	Buffer for the name of the attribute
	data_type	OUT:	Data type of the attribute
	count	OUT:	Number of attribute values

	Purpose	Retrieves information about an attribute.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	GRattrinfo retrieves the name, data type, and number of values of the attribute, specified by its index, attr_index, for the data object identified by the parameter obj_id. The name is stored in the parameter name, the data type is stored in the parameter data_type, and the number of values is stored in the parameter count. If the value of any of the output parameters is NULL, the corresponding information will not be retrieved.
		The value of the parameter attr_index can be obtained using GRfindattr, GRnametoindex or GRreftoindex, depending on available information. Valid values of attr_index range from 0 to the total number of attributes attached to the object - 1. The total number of attributes attached to the file can be obtained using the routine GRfileinfo. The total number of attributes attached to an image can be obtained using the routine GRgetiminfo .

	FORTRAN	integer function mgatinf([obj]_id, attr_index, name, data_type, count)
		integer [obj]_id, data_type, attr_index, count
		character*(*) name