LPRngInfo for Win32 (NT/2000)

Version 1.2b
Copyright 2000 University of Wisconsin - Madison, CAE Center

Obtaining LPRngInfo
Download source code
Overview
System Requirements
Installing and configuring LPRngInfo
Revision History

Obtaining LPRngInfo

There are two versions of LPRngInfo available. One version contains support for getting status information of HP printers via SNMP. The other, version does not contain this support and does not require two additional DLL files.

The HP Printer Status version uses SNMP++ which is open source found at:

http://rosegarden.external.hp.com/snmp++/index.html

The copyright information for SNMP++ is:

The SNMP_PP.DLL is included with the distribution of LPRngInfo. This DLL requires the WinSNMP library (WSNMP32.DLL). An evaluation version can be obtained from ACE*COMM at http://www.acecomm.com/.

Overview

LPRngInfo is a WinNT/2000 utility that will allow you to view and slightly manage your Unix based print queues. This program assumes you are using LPRng for your print system. Geared mainly for our helpdesk, this program presents a easy to use GUI environment to display the print activity on our Unix system. The main window (shown below) allows you to see at a quick glance a summary of print queues. The LPRng print queues listed can come from multiple hosts if desired.

Viewing the Queue

By double-clicking on a queue entry, or selecting an entry and pressing the Show Jobs button, the program will bring up the list of jobs in the specified queue as well as some LPRng Status information. From this window, you can delete print jobs. The program will obtain the NT user name of the person logged into the machine and send that name in the request to LPRng to delete a job. The user must have rights on the remote system to be able to delete a job. If they don't, you will get an error.

As with the main window, the list will auto-refresh every so often (configurable). The user also has the option to force a refresh by pressing the Refresh button.

Support for HP Printers

One version of the program has support for getting status information from HP printers via SNMP. This version requires two additional DLLs (see Obtaining LPRngInfo for details). When enabled, the program will query the specified printers via SNMP and obtain the status information (Out of paper, Toner Low, Paper Jam, etc). This process has been placed into the background as it can take a long time to refresh the display if the list of printers is long. Once the background thread polls all the printers, it will pause for a configurable amount of time before starting to poll all the printers again.

The program uses HP's SNMP++ which uses WinSNMP.

System Requirements

There are two requirements for this program. This program was written to work with Windows NT (uses user security information to obtain the currently logged in user. If someone has a better way of doing this so it will work on Windows9x and NT/2000, feel free to modify the source and send me the update). It may work under Win9x, but I have not tested it.

The other requirement is that you use LPRng for your print system. LPRngInfo relies on the output from LPRng to populate the windows with information. LPR daemons for the various Unix systems will differ in the output and can't be used. This has been tested with LPRng version 3.5.3.

Installing and configuring LPRngInfo

Installation is fairly simple. You need to place the executable and its config file LPRngInfo.cfg in the same directory. Edit the LPRngInfo.cfg file to your liking. If you are using the HP Printer Supported version, you also need to copy the DLL files SNMP_PP.DLL and WSNMP32.DLL to the same directory as the application (or they could be in the system's path).

LPRngInfo.cfg

The config file is fairly simple. Any line starting with a pound sign (#) is treated as a comment. The rest of the config file is formated like most windows INI files.

[options] section

In this section, you can set up a few items to control the program's behaviour. The options are fairly self explanitory:

AutoRefresh = <value>
This enables/disables the program's automatic refresh of the displayed information. If for some reason you don't want to have the program update on its own and just use the refresh buttons, you can disable it here.
If this value is set to a 1 or Y, then it is enabled. Any other value disables AutoRefresh
QueueRefreshTime = <value in seconds>
Specifies the number of seconds to wait before updating the display. The value is specified in seconds. For this to work, you need to enable the AutoRefresh option.
QueuJobRefreshTime = <value in seconds>
This is the amount of time to wait between updating the information in the queue job list. This way, you can have that window update more frequently than when viewing the entire queue summary.
ShowErrorJobs=<value>
This setting will show or hide jobs with errors. These jobs are not considered by LPRng to be printable. Often they happen when there was a timeout from the printing client transferring the print job into the queue. A value of 1 or Y will enable the display of the error jobs in the queue.
UseNTUserName=<value>
This specifies if the program should use the user name of the person logged into the machine as the name to be sent to the remote LPR daemon when making a delete request. A value of 1 or Y will have the program use the logged in user. If not, be sure to specify a user with the RemoteUserName option.
RemoteUserName=<value>
The name of the user to send with the delete a job request. If UseNTUserName is not set, then this will be the name of the user to send.
ShowHPStatus=<value>
If using the SNMP enabled version, you can disable the display of the printer status information. Setting this value to 1 or Y will enable the display and start the background polling thread. This was added prior to me deciding to distribute two versions (one of which doesn't require the extra DLL files)
HPPrinterSTatusRefreshTime=<value in seconds>
The amount of time to wait before starting an update of the printer information via SNMP.

An example of these options is below:

[Options]
AutoRefresh = 1
QueueRefreshTime=60
QueueJobRefreshTime = 30
ShowHPStatus=0
HPPrinterStatusRefreshTime=60
ShowErrorJobs=0
UseNTUserName=0
RemoteUserName=root

[printers] section

This is the section where you define the printers. The format of the entries in this section is:

<print queue>@<hostname>

If you are using the HP version, then the format of the line changes just slightly to allow you to specify the hostname of the actual printer. The format is:

<print queue>@<hostname>:<hp printer hostname>

Both formats can be used in either version of the program. In the non-SNMP aware version, the hp printer host information is just ignored.

For example, if you had two Unix systems with LPRng installed. One one system (unix1.mydomain.org) you have the print queues my_laser and hp_laser configured and on the other (unix2.mydomain.org) you have the print queue local_printer. The printers my_laser and hp_laser are HP printers with JetDirect cards in them. The hostname for my_laser is myprinter.mydomain.org and the hostname for hp_laser is hpprinter.mydomain.org. The config file would look like the following for this setup:

[printers]
my_laser@unix1.mydomain.org:myprinter.mydomain.org
hp_laser@unix1.mydomain.org:hpprinter.mydomain.org
local_printer@unix2.mydomain.org

Version History

Version 1.2b

BUGFIX: background timers were not getting turned off when the config file said "no auto update"
Added the ability to specify the user name for the delete request in the config file.
Source code made available starting with this release. Source is available under the Artistic License.

Version 1.2a

BUGFIX: Changed the way the program finds its config file. It used to look in the "current working directory", and now it looks at the directory where the .EXE is located.
Created a separate build that didn't require the SNMP_PP.DLL and WSNMP32.DLL

Version 1.2

Added SNMP polling of HP Printers
Added ability to remove jobs from a queue (if remote side lets you)
Added ability to configure the program via LPRngInfo.CFG. No longer hard coding in all the printer information
BUGFIX: Clicking on "Show Jobs" when no item was selected resulted in a GPF.

Version 1.1

Changed the way the print queue jobs are displayed. It is now shown in a multi-column list box
Added timers to enable auto-refresh of the display

Version 1.0

Initial writing of the program