When you call ds_read( ) to read one or more attributes from a CDS entry, you specify in the DS_C_ENTRY_INFO_SELECTION object the entry attributes you want to read.
The DS_C_ENTRY_INFO_SELECTION object contains the attributes shown in the following figure.
The DS_C_ENTRY_INFO_SELECTION Object
Note that this object class has no subobjects.
· OM_CLASS
The value of this attribute is an OID string that identifies the object's class; its value is always DS_C_ENTRY_INFO_SELECTION.
· DS_ALL_ATTRIBUTES
This attribute is a simple Boolean option whose value indicates whether all the entry's attributes are to be read, or only some of them. Its possible values are as follows:
- OM_TRUE, meaning that all attributes in the directory entry should be read. Any values specified by the DS_ATTRIBUTES_SELECTED attribute are ignored.
- OM_FALSE, meaning that only some of the entry attributes should be read; namely, those specified by the DS_ATTRIBUTES_SELECTED attribute.
· DS_ATTRIBUTES_SELECTED
The value of this attribute, which is an OID string, identifies the entry attribute to be read. Note that this attribute's value has meaning only if the value of DS_ALL_ATTRIBUTES is OM_FALSE; if it is OM_TRUE, the value of DS_ATTRIBUTES_SELECTED is ignored.
Note also that there are multiple instances of this attribute if more than one attribute, but not all of them, is to be selected for reading. Each separate instance of DS_ATTRIBUTES_SELECTED has as its value an OID string that identifies one directory entry attribute to be read. If DS_ATTRIBUTES_SELECTED is present but does not have a value, ds_read( ) reads the entry but does not return any attribute data; this technique can be used to verify the existence of a directory entry.
· DS_INFO_TYPE
The value of this attribute specifies what information is to be read from each attribute specified by DS_ATTRIBUTES_SELECTED. The two possible values are as follows:
- DS_TYPES_ONLY, meaning that only the attribute types of the selected attributes should be read.
- DS_TYPES_AND_VALUES, meaning that both the attribute types and the attribute values of the selected attributes should be read.