Files Reference

qconfig File

Purpose

Configures a printer queuing system.

Description

The /etc/qconfig file describes the queues and devices available for use by both the enq command, which places requests on a queue, and the qdaemon command, which removes requests from the queue and processes them. The qconfig file is an attribute file.

Some stanzas in this file describe queues, and other stanzas describe devices. Every queue stanza requires that one or more device stanzas immediately follow it in the file. The first queue stanza describes the default queue. Unless the LPDEST or PRINTER environment variable is set, the enq command uses this queue when it receives no queue parameter. If LPDEST contains a value, that value takes precedence over the PRINTER environment variable. Destination command-line options always override both variables.

The name of a queue stanza can be from 1 to 20 characters long. Some of the fields and their possible values that can appear in this file are:

Field	Definition
`acctfile`	Identifies the file used to save print accounting information. FALSE, the default value, indicates suppress accounting. If the named file does not exist, no accounting is done.
`device`	Identifies the symbolic name that refers to the device stanza.
`discipline`	Defines the queue serving algorithm. The default value, fcfs, means first-come-first-served. sjn means shortest job next.
`up`	Defines the state of the queue. TRUE, the default value, indicates that the queue is running. FALSE indicates that it is not running.

Note

lp is a BSD standard reserved queue name and should not be used as a queue name in the qconfig file.

The following list shows some of the fields and their possible values that appear in the qconfig file for remote queues:

`host`	Indicates the remote host where the remote queue is found.
`s_statfilter`	Specifies the short version filter used to translate remote queue status format. The following are possible values: /usr/lib/lpd/bsdshort BSD remote system /usr/lib/lpd/aixv2short RT remote system /usr/lib/lpd/attshort AT&T remote system
`l_statfilter`	Specifies the long version filter used to translate remote queue status format. The following are possible values: /usr/lib/lpd/bsdlong BSD remote system /usr/lib/lpd/aixv2long RT remote system /usr/lib/lpd/attlong AT&T remote system
`rq`	Specifies the remote queue name. In a remote print environment, the client configuration should specify the remote queue name or the server. Using the default remote queue name may cause unpredictable results.

If a field is omitted, its default value is assumed. The default values for a queue stanza are:

discipline = fcfs
up         = TRUE
acctfile   = FALSE

The device field cannot be omitted.

The name of a device stanza is arbitrary and can be from 1 to 20 characters long. The fields that can appear in the stanza are:

Field	Definition
`access`	Specifies the type of access the backend has to the file specified by the file field. The value of access is write if the backend has write access to the file or both if it has both read and write access. This field is ignored if the file field has the value FALSE.
`align`	Specifies whether the backend sends a form-feed control before starting the job if the printer was idle. The default value is TRUE.
`backend`	Specifies the full path name of the backend, optionally followed by the flags and parameters to be passed to it. The path names most commonly used are /usr/lib/lpd/piobe for local print and /usr/lib/lpd/rembak for remote print.
`feed`	Specifies either the number of separator pages to print when the device becomes idle or the value never, the default, which indicates that the backend is not to print separator pages.
`file`	Identifies the special file where the output of backend is to be redirected. FALSE, the default value, indicates no redirection and that the file name is /dev/null. In this case, the backend opens the output file.
`header`	Specifies whether a header page prints before each job or group of jobs. A value of never, the default value, indicates no header page at all. always means a header page before each job. group means a header before each group of jobs for the same user. In a remote print environment, the default action is to print a header page and not to print a trailer page.
`trailer`	Specifies whether a trailer page prints after each job or group of jobs. A value of never, the default, means no trailer page at all. always means a trailer page after each job. group means a trailer page after each group of jobs for the same user. In a remote print environment, the default action is to print a header page and not to print a trailer page.

The qdaemon process places the information contained in the feed, header, trailer, and align fields into a status file that is sent to the backend. Backends that do not update the status file do not use the information it contains.

If a field is omitted, its default value is assumed. The backend field cannot be omitted. The default values in a device stanza are:

file    = FALSE
access  = write
feed    = never
header  = never
trailer = never
align   = TRUE

The enq command automatically converts the ASCII qconfig file to binary format when the binary version is missing or older than the ASCII version. The binary version is found in the /etc/qconfig.bin file.

Note

The qconfig file should not be edited while there are active jobs in any queue. Any time the qconfig file is changed, jobs submitted prior to the change will be processed before jobs submitted after the change.

Editing includes both manual editing and use of the mkque, rmque, chque, mkquedev, rmquedev, or chquedev command. It is recommended that all changes to the qconfig file be made using these commands. However, if manual editing is desired, first issue the enq -G command to bring the queuing system and the qdaemon to a halt after all jobs are processed. Then edit the qconfig file and restart the qdaemon with the new configuration.

Examples

The batch queue supplied with the system might contain these stanzas:
```
bsh:
  discipline = fcfs
  device = bshdev
bshdev:
  backend = /usr/bin/ksh
 
```
To run a shell procedure called myproc using this batch queue, enter:
```
qprt -Pbsh myproc
```
The queuing system runs the files one at a time, in the order submitted. The qdaemon process redirects standard input, standard output, and standard error to the /dev/null file.

To allow two batch jobs to run at once, enter:

bsh:
  discipline = fcfs
  device = bsh1,bsh2
bsh1:
  backend = /usr/bin/ksh
bsh2:
  backend = /usr/bin/ksh

To set up a remote queue, bsh, enter:

remh:
  device = rd0
  host = pluto
  rq = bsh
rd0:
  backend = /usr/lib/lpd/rembak

Files

/etc/qconfig	Contains the configuration file.
/etc/qconfig.bin	Contains the digested, binary version of the /etc/qconfig file.
/dev/null	Provides access to the null device.
/usr/lib/lpd/piobe	Specifies the path of the local printer backend.
/usr/lib/lpd/rembak	Specifies the path of the remote printer backend.
/usr/lib/lpd/digest	Contains the program that converts the /etc/qconfig file to binary format.

Related Information

The enq command, lp command, qdaemon command.

Understanding the Interaction between qdaemon and the Backend in AIX 5L Version 5.2 General Programming Concepts: Writing and Debugging Programs.

Printer Overview and Spooler Overview in AIX 5L Version 5.2 Guide to Printers and Printing.