LP Print Service

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

LP Print Service Commands

The following table lists frequently used LP print service commands.

Table 13-2 LP Print Service Commands

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

Functions of the LP Print Service

The LP print service performs the following functions:

• Administers files and schedules local print requests

• Receives and schedules network requests

• Filters files, if necessary, so they print properly

• Starts programs that interface with the printers

• Tracks the status of print jobs

• Tracks forms that are mounted on the printer

• Tracks print wheels that are currently mounted

• Delivers alerts to mount new forms or different print wheels

• Delivers alerts about printing problems

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 13-3 Contents of the /usr/lib/lp Directory

LP Print Service Directories

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

Table 13-4 Directories for the LP Print Service

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 13-5 Contents of the /etc/lp Directory

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

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.

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. 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.

Required terminfo Items For a Printer

The following three tables list the terminfo items that are required for a printer.

Table 13-6 Required terminfo Items for a Printer (Booleans)

Table 13-7 Required terminfo Items for a Printer (Numbers)

Table 13-8 Required terminfo Items for a Printer (Strings)

LP Print Service Log Files

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

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 13-9 Codes in the requests Log File

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

Table 13-10 Outcome Codes in the requests Log File

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 13-11 Contents of the /var/spool/lp 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 Oracle 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 non-PostScript 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 Oracle 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.