Specifications

4-153
Printer, Plotter, and Spooler Subsystem Programming
Editing the /etc/qconfig File
The /etc/qconfig configuration file can be edited with your text editor of choice. There are
unenforced rules concerning when you can and cannot edit the /etc/qconfig file without
halting or otherwise corrupting the operation of the spooler.
Modifying the /etc/qconfig File while Jobs are Processing
The /etc/qconfig file should never be edited when jobs are processing. This is especially
true when your system has a large number (greater than 25) of printers that are generally
pretty busy. When the qdaemon receives notification from enq that a new Job Description
File (JDF) exists, the qdaemon examines the dates on both /etc/qconfig and
/etc/qconfig.bin, the binary version of /etc/qconfig. If /etc/qconfig is younger than
/etc/qconfig.bin, the qdaemon does not accept any new jobs, including the one that
caused it to examine the aforementioned files, until all currently running jobs have finished
processing. When the jobs have finished processing, the qdaemon creates a new version
of /etc/qconfig.bin.
If you cause the qdaemon to go into this state while jobs are processing, it is possible for
the spooler to hang. If you modify /etc/qconfig under these conditions, and if any printers
are still generating output, your best option is to leave the system alone and see if it comes
back to life after all the jobs have finished processing. If zero printers are producing output
or the spooler appears to be hung, see Cleaning Up and Starting Over on page 5-20.
Attention: Do not cause a change to /etc/qconfig while jobs are processing. Aside from
editing /etc/qconfig and writing a new version of the file to disk with a text editor, you
can cause the same effect by using the smit command to change a queue property or a
parameter value.
Creating Queue with an Editor
The root user can edit /etc/qconfig and define queues with a text editor. One situation
where this should not be done is when the backend for the spooler queue is piobe. Queues
that use piobe as backend must have an associated virtual printer definition. In this
situation, the root user should use the smit command to create the queue. Using the smit
command will run several programs that create the virtual printer definition.