SPI Common Extensions Manual

Glossary
SPI Common Extensions Manual—427508-001
Glossary-7
nonsensitive command
nonsensitive command. A command that does not affect the state of an object.
Nonsensitive commands can be issued by any user or program that is allowed access
to the subsystem. Most informational commands are nonsensitive. Compare with
sensitive command.
null value. A value in a field of an extensible structure indicating that no value was assigned
by the sending process. Null values are initialized by the SSNULL procedure.
object. In SPI, an entity subject to independent reference and control by a subsystem; for
example, the disk volume $DATA or the data communications line $X2502. An object
typically has a name and a type known to the controlling subsystem. In DDL, an item in
a dictionary. DDL assigns each object a unique object number for identification.
object type. A category of objects to which a specific object belongs. For example, a
specific disk file might have the object type FILE and a specific terminal the object type
SU. A subsystem identifies a set of object types for the objects it manages. The
operator interface to the subsystem might have keywords to identify the types.
Correspondingly, the programmatic interface would have object-type numbers suitable
for passing to the SPI SSINIT procedure. In DDL, one of the six types of dictionary
objects: records, DEFs, constants, token types, token codes, and token maps.
object-name template. An object name, provided in a command, which the subsystem
compares with the names of its objects to identify those to which the command should
be applied. Some subsystems allow wild-card characters in object-name templates.
object-name token. A parameter or response token that identifies, by name, a particular
object of a given object type. An object-name token is a kind of object-selector token.
See object-selector token.
object-selector token. A token that identifies one or more specific objects to operate on, of
the object type given in the command. Typically, the value of such a token is either
some form of object name or an object number. An object-name token is a kind of
object-selector token. See object-name token.
object-type number. A number that represents an object type managed by a subsystem.
Each subsystem with a token-oriented programmatic interface can have its own set of
object-type numbers, which are represented in DDL by constants and in programs by
TAL literals or defines, COBOL level-01 variables, or TACL text variables. (In some
cases, object-type numbers are shared by several subsystems.) The object-type
number is a header token in commands and responses. See object type.