LP Print Service

This section describes the directory structure, files, and logs of the LP print service.

LP Print Service Commands

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Note - The LP Print Service client commands have been modified to be a consumer of the FSG OpenPrinting Open Standard Print API (PAPI). These print commands are layered on top of the PAPI. See How PAPI Is Implemented in the Solaris OS for more information.

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The following table lists frequently used LP print service commands.

Table 11-2 LP Print Service Commands

Command	Task	Man Page
enable	Activate a printer	enable(1)
cancel	Cancel a print request	cancel(1)
lp	Send one or more file or files to a printer	lp(1)
lpstat	Report the status of the LP print service	lpstat(1)
disable	Deactivate on or more printers	enable(1)
accept	Permit print requests to be queued for a specific destination	accept(1M)
reject	Prevent print requests from being queued for a specific destination	accept(1M)
lpadmin	Set up or change a printer configuration	lpadmin(1M)
lpfilter	Set up or change filter definitions	lpfilter(1M)
lpforms	Set up or change preprinted forms	lpforms(1M)
lpadmin	Mount a form	lpadmin(1M)
lpmove	Move output requests from one destination to another destination	lpmove(1M)
lpsched	Start the LP print service scheduler	lpsched(1M)
lpshut	Stop the LP print service scheduler	lpshut(1M)
lpusers	Set or change the default priority and priority limits that can be requested of the LP print service by users	lpusers(1M)

For information about Solaris print commands that have been modified for use with the PAPI, see How PAPI Is Implemented in the Solaris OS.

Daemons and LP Internal Files

The /usr/lib/lp directory contains daemons and files used by the LP print service, as described in the following table.

Table 11-3 Contents of the /usr/lib/lp Directory

File	Type	Description
bin	Directory	Contains files for generating printing alerts, slow filters, and queue management programs.
model	Directory	Contains the standard printer interface program.
postscript	Directory	Contains all PostScript filter programs provided by the LP print service. These filters come with descriptor files in the /etc/lp/fd directory. These files tell the LP print service the characteristics of the filters and where to locate them.

LP Print Service Directories

The files of the LP print service are distributed among the directories that are shown in the following table.

Table 11-4 Directories for the LP Print Service

Directory	Contents
/usr/bin	The LP print service user commands.
/etc/lp	A hierarchy of LP server configuration files.
/usr/share/lib	The terminfo database directory.
/usr/lib/print	The lp conversion scripts, in.lpd daemon, and the printd daemon. The printd daemon transfers all pending jobs in the/var/spool/print directory once per minute. When no jobs are remaining to transfer, the printd daemon exits.
/usr/sbin	The LP print service administrative commands
/usr/lib/lp	The lpsched program, binary files, PostScript filters, and the model directory, which contains the standard printer interface program.
/var/lp/logs	LP log files such as lpsched.n (which includes messages from lpsched) and requests.n (which includes information about completed print requests).
/var/spool/lp	The spooling directory where files are queued for printing.
/var/spool/print	The staging area for LP print service client-side requests.
/etc/lp/model/uri	The location of the interface script that process device-uri information.

LP Print Service Configuration Files

The lpsched daemon stores configuration information in the /etc/lp directory, as described in the following table.

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Caution - The configuration files listed in this table are private interfaces. These files are subject to change in future releases. You should not build software that relies on these files being in their current locations or that relies on the data being in the format currently used.

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Table 11-5 Contents of the /etc/lp Directory

File	Type	Description
classes	Directory	Files identifying classes provided by the lpadmin -c command.
fd	Directory	Description of existing filters.
filter.table	File	Print filter look-up table.
forms	Directory	Location to put files for each form. Initially, this directory is empty.
interfaces	Directory	Printer interface program files.
logs	Link to /var/lp/logs	Log files of printing activities.
model	Link to /usr/lib/lp/model	The standard printer interface program.
printers	Directory	Directories for each local printer. Each directory contains configuration information and alert files for an individual printer.
pwheels	Directory	Print wheel files or cartridge files.
ppd	Directory	Each local queue that is configured with a PPD file has a copy of the PPD file placed here.

These configuration files serve a function similar to the /etc/printcap file on LPD-based print servers.

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Note - You can check the contents of the configuration files, but you should not edit these files directly. Instead, use the lpadmin command to make configuration changes. Your changes are written to the configuration files in the /etc/lp directory. The lpsched daemon administers and updates the configuration files.

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The /etc/lp/printers directory has a subdirectory for each local printer that is known to the system. The following example shows the /etc/lp/printers subdirectories of printers sparc1 and luna.

$ ls -l /etc/lp/printers
drwxrwxr-x 2 lp lp 512 Jan 23 23:53 luna
drwxrwxr-x 2 lp lp 512 Jan 11 17:50 sparc1

The following table describes the files within each printer-specific directory.

File Name	Description
alert.sh	Shell to execute in response to alerts
alert.vars	Alert variables
configuration	Configuration file
users.deny	List of users to whom printer access is denied
comment	Printer description

The configuration file for the printer luna, /etc/lp/printers/luna/configuration, would typically appear as follows:

Banner: on: Always
Content types: PS
Device: /dev/term/b
Interface: /usr/lib/lp/model/standard
Printer type: PS
Modules: default

The terminfo Database

The /usr/share/lib directory contains the terminfo database directory. This directory contains definitions for many types of terminals and printers. The LP print service uses information in the terminfo database to perform the following tasks:

• Initializes a printer

• Establishes a selected page size, character pitch, line pitch, and character set

• Communicates the sequence of codes to a printer

Each printer is identified in the terminfo database with a short name. For a description of the structure of the terminfo database, see Printer Type. If necessary, you can add entries to the terminfo database, but doing so is tedious and time-consuming. For more information, see Adding a terminfo Entry for an Unsupported Printer.

Printer Names in the terminfo Database

Information about each printer type is stored in the terminfo database (/usr/share/lib/terminfo). This information includes the printer capabilities and initialization control data. The printer you install must correspond to an entry in the terminfo database.

$ pwd
/usr/share/lib/terminfo
$ ls
1  3  5  7  9  B  H  P  a  c  e  g  i  k  m  o  q  s  u  w  y
2  4  6  8  A  G  M  S  b  d  f  h  j  l  n  p  r  t  v  x  z
$ 

Each subdirectory contains compiled database entries for terminals or printers. The entries are organized by the first letter of the printer or terminal type. For example, if you have an Epson printer, look in the /usr/share/lib/terminfo/e directory to find your particular model of Epson printer.

$ cd /usr/share/lib/terminfo/e
$ ls
emots           ep2500+high   ep48            ergo4000      exidy2500
env230          ep2500+low    epson2500       esprit
envision230     ep40          epson2500-80    ethernet
ep2500+basic    ep4000        epson2500-hi    ex3000
ep2500+color    ep4080        epson2500-hi80  exidy
$ 

The entries for Epson printers begin with epson.

If you have an NEC printer, look in the /usr/share/lib/terminfo/n directory for your NEC printer model.

$ cd /usr/share/lib/terminfo/n
$ ls
ncr7900        ncr7900iv      netronics      network        nuc
ncr7900-na     ncr7901        netty          netx           nucterm
ncr7900i       nec            netty-Tabs     newhp
ncr7900i-na    net            netty-vi       newhpkeyboard
$ 

The nec entry in this directory is for the NEC printer.

LP Print Service Log Files

The LP print service maintains two sets of log files that are described in the following table.

Log File Name	Description
syslogd	Set lpr.debug in /etc/syslog.conf to enable LP print service logging
/var/spool/lp	A list of current requests that are in the print queue
/var/lp/logs/requests	An ongoing history of print requests

Print Queue Logs

The scheduler for each system keeps a log of print requests in the /var/spool/lp/tmp/system and /var/spool/lp/requests/system directories. Each print request has two files, one file in each directory, that contain information about the request. The information in the /var/spool/lp/requests/system directory can be accessed only by superuser or lp. The information in the /var/spool/lp/tmp/system directory can be accessed only by the user who submitted the request, superuser, or lp.

The following example shows the contents of the /var/spool/lp/tmp/starbug directory:

$ ls /var/spool/lp/tmp/starbug
5     5-0
# cat 5-0
C 1
D print1
F /etc/profile
P 20
T /etc/profile
t simple
U root
s 0000
v 2

These files remain in their directories only as long as the print request is in the queue. Once the print request is finished, the information in the files is combined and appended to the /var/lp/logs/requests file. This file is described in the next section.

Use the information in the /var/spool/lp/logs directory if you need to track the status of a print request that is currently in the queue.

History Log Files

The LP print service records a history of printing services in two log files, lpsched and requests. These log files are located in the /var/lp/logs directory. You can use the information in these log files to diagnose and troubleshoot printing problems. An example of the contents of the /var/lp/logs directory is as follows:

# cd /var/lp/logs
# ls
lpsched.1    requests    requests.2
lpsched      lpsched.2   requests.1
# 

The two most important log files for troubleshooting are the following:

• The lpsched log file — Contains information about local printing requests.

• The requests log file — Contains information about print requests that are completed and no longer in the print queue.

The requests log file has a simple structure so that you can extract data using common UNIX shell commands. Requests are listed in the order they are printed. They are also separated by lines showing their request IDs. Each line below the separator line, the line that starts with =, is marked with a single letter that identifies the kind of information contained in that line. Each letter is separated from the data by a single space.

The following example shows the contents of a requests log file:

# pwd
/var/lp/logs
# tail requests.2
= print1-3, uid 0, gid 1, size 206662, Wed Mar 14 08:56:30 MST 2003
z print1
C 1
D print1
F /usr/dict/words
P 20
T /usr/dict/words
t simple
U root
s 0x0014
v 2
#

The following table shows the letter codes and the content of their corresponding lines in the requests log file.

Table 11-6 Codes in the requests Log File

Letter	Content of Line
=	The separator line, which contains the following items: request ID, user ID (UID), and group IDs (GIDs) of the user, the total number of bytes in the original (unfiltered) file size, and the time when the request was queued.
z	The name of the printer.
C	The number of copies printed.
D	The printer or class destination, or the word any.
F	The name of the file printed. The line is repeated for each file printed. Files were printed in the order shown.
f	(Optional) The name of the form used.
H	(Optional) One of three types of special handling: resume, hold, and immediate.
N	(Optional) The type of alert used when the print request was successfully completed. The type is the letter M if the user was notified by email or W if the user was notified by a message to the terminal.
O	(Optional) The printer-dependent -o options. For example, nobanner.
P	The priority of the print request.
p	The list of pages printed.
r	(Optional) A single-letter line that is included if the user asked for “raw” processing of the files with the lp -r command.
S	(Optional) The character set, print wheel, or cartridge used.
T	The title placed on the banner page.
t	The type of content found in the files.
U	The name of the user who submitted the print request.
s	The outcome of the request, shown as a combination of individual bits expressed in hexadecimal format. Several bits are used internally by the print service. The bits and what they mean are described in the following table.
v	0 — Identifies that the print job originated from the in.1pd print daemon or another system on the network. 2 — Identifies that the print job originated from the /usr/bin/lp or /usr/ucb/lpr commands. 1 — Identifies that the print job originated from an older version of the printing software.
x	(Optional) The slow filter used for the print request.
Y	(Optional) The list of special modes for the print filters used to print the request.
z	(Optional) The printer used for the request. This printer differs from the destination (the D line) if the request was queued for any printer or a class of printers, or if the request was moved to another destination.

The following table shows the outcome codes in the LP requests log file and their descriptions.

Table 11-7 Outcome Codes in the requests Log File

Outcome Code	Description
0x0001	The request was held pending resume.
0x0002	Slow filtering is running.
0x0004	Slow filtering finished successfully.
0x0008	The request is on the printer.
0x0010	Printing finished successfully.
0x0020	The request was held pending user change.
0x0040	The request was canceled.
0x0080	The request will print next.
0x0100	The request failed filtering or printing.
0x0200	The request is in transit to a remote printer (obsolete).
0x0400	The user will be notified.
0x0800	A notification is running.
0x1000	A remote system has accepted the request (obsolete).
0x2000	The administrator placed a hold on the request.
0x4000	The printer had to change filters.
0x8000	The request is temporarily stopped.

Spooling Directories

Files queued for printing are stored in the /var/spool/lp directory until they are printed, which might be only seconds. The following table shows the contents of the /var/spool/lp directory.

Table 11-8 Contents of the /var/spool/lp Directory

File	Type	Description
SCHEDLOCK	File	Lock file for the scheduler. Check for this file if the scheduler terminates and will not restart.
admins	Directory	Link to /etc/lp.
bin	Directory	Link to /usr/lib/lp/bin.
logs	Link	Link to ../lp/logs where completed print requests are logged.
model	Link	Link to /usr/lib/lp/model.
requests	Directory	Directory that contains subdirectories for each configured printer where print requests are logged until printed. Users cannot access this log.
system	Directory	A print status file for the system.
temp	Link	Link to /var/spool/lp/tmp/hostname, which contains the spooled requests.
tmp	Directory	Directory for each configured printer where print requests are logged until printed. Changes to existing print requests are also recorded in this directory.

Filtering Print Files

Print filters are programs on the print server that convert the content of a queued file from one format to another format.

A print filter can be as simple or as complex as needed. The Solaris OS provides print filters in the /usr/lib/lp/postscript directory that cover most situations where the destination printer requires the data to be in PostScript format. If you need filters for nonPostScript printers, you have to create the filters and add them to the systems that need filters.

A set of print filter descriptor files are provided in the /etc/lp/fd directory. These descriptor files describe the characteristics of the filter (for example, fast or slow filter). These description files point to the filter program (for example, to /usr/lib/lp/postscript/postdaisy).

How the Printer Interface Program Works

The LP print service interacts with other parts of the Solaris OS. The print service uses a standard printer interface program to do the following:

• Initialize the printer port, if necessary. The standard printer interface program uses the stty command to initialize the printer port.

• Initialize the printer. The standard printer interface program uses the terminfo database and the TERM shell variable to find the appropriate control sequences.

• Print a banner page, if necessary.

• Print the correct number of copies specified by the print request.

The LP print service uses the standard interface program, found in the /usr/lib/lp/model directory, unless you specify a different program. You can create custom interface programs. However, you must make sure that the custom program does not terminate the connection to the printer or interfere with proper printer initialization.