Technical data

1.1.1.1 Client Programs

Client programs allow users to initiate print, list, and system administration

operations. Upon receipt of a request, a server performs the operation and

sends a result back to the client. Depending on the request, the result

could be a simple acknowledgment, an error code, or a set of requested

information, such as a formatted list of print jobs.

The following client programs are supported:

• Command Line Interface (CLI) utilities – Provide a set of commands that

perform the operations supported by server processes.

• Graphical User Interface (GUI) utilities – Provides graphical interfaces

to perform the operations supported by server processes.

• LPD Inbound Gateway Daemon – Accepts print jobs from

lp and lpr

print systems and submits them to Advanced Printing Software servers.

1.1.1.2 Server Programs

There are two types of server programs:

• Spoolers – Collect printer jobs, associate them with print queues, and

schedules them for printing.

• Supervisors – Take jobs from spooler queues and print them according

to the job requirements and printer capabilities. The supervisor

communicates with printers and reports printer status to the spooler

and to clients.

Every configuration includes at least one spooler and one supervisor. Each

spooler and supervisor manages a database of persistent print objects.

All objects in the print system, except for physical printers, are created

and stored in a spooler database. Physical printer objects are stored in a

supervisor database.

The spooler is viewed as the primary server in the system. Supervisors are

nearly invisible to end users.

1.1.2 Objects and Object Attributes

The print system architecture is described in terms of named objects and

object attributes. Objects include printers, queues, print jobs, and so on.

Attributes of an object describe the object. Examples of attributes are printer

names, document formats, and job identifiers.

The following objects are defined in Advanced Printing Software:

• Server

• Printer

1–2 Advanced Printing Software Overview