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Defining Attribute Type Encoding

You must define the format of values that can be supplied for an attribute type in the attribute type's encoding. An attribute can be assigned only those values that are in the format defined in the encoding. For example, the encoding can specify that instances of this attribute type contain values only in the form of UUIDs.

Each attribute type can have only one encoding and that encoding cannot be modified. In addition, a special encoding type lets you create attribute sets.

Use the dcecp xattrschema -encoding option to specify an attribute's encoding. This option has the following form:

-encoding type

The type parameter is one of the encoding types described in the following table.


Encoding Types

Encoding Type Meaning
any This attribute value can take on any encoding. This encoding type is only legal for the definition of an ERA in a schema entry. All instances of an ERA must have an encoding of some other value.
attrset The attribute value must be a list of attribute type UUIDs enclosed in braces. This encoding type defines an attribute set. Attribute sets allow for easier attribute search and retrieval. For instance, a query on an attribute set returns all instances of attributes that are members of the set.
binding The attribute value must consist of authentication, authorization, and binding information suitable for communicating with a DCE server. Use this encoding if you want to store a name or server binding as an object's attribute. See Specifying the Binding Information for more information.
byte The attribute value must be a string of bytes. The byte string is assumed to be a pickle or is otherwise a self-describing type. Note that this encoding type allows entry of binary data. See the xattrschema(8dce) reference page for more information on entering binary data.
confidential Not implemented in this release of DCE.
i18ndata The attribute value must be an internationalized string of bytes with a tag identifying the OSF registered codeset used to encode the data. Note that this encoding type allows entry of binary data. See the xattrschema(8dce) reference page for more information on how to enter binary data.
integer The attribute value must be a signed 32-bit integer.
printstring The attribute instance value must be a character string printable by the PCS.
stringarray The attribute value must be an array of one of more printstrings. Note that the printstring can be a null.
uuid The attribute value must be a DCE UUID.
void The attribute has no value. It is simply a marker that is either present or absent.