PRINTCAP(5)

NAME

printcap - printer capability data base

SYNOPSIS

printcap database

DESCRIPTION

The format of the LPRng printcap database was based on the termcap(5) data base file format. Entries in the printcap Each entry in the data base is used to define various options and values to control the printing and spooling of print jobs.

LPD.CONF, SYSTEM AND USER PRINTCAP FILES

Default configuration values are read from the LPRng configuration file //etc/lprng/lpd.conf, consult the lpd.conf(5) man page for details about them. The system printcap file //etc/printcap contains information common to all users and the LPRng printing system. Finally, the user printcap files is in ${HOME}/.printcap and contain user configurable information for printer information. The values in the user printcap file override values in the printcap file which override the default values in the //etc/lprng/lpd.conf file.

The user printcap file is used by client programs such as lpr , lprm , lpq , and lpq to allow the user to define either a special set of printers, provide additional configuration information, or to modify default settings in the //etc/printcap, or //etc/lprng/lpd.conf file.

CAPABILITIES

The printcap database files format is based on the termcap (5) database format, modified as follows. Leading whitespace on each line is discarded, and blank lines or lines which then start with a comment character (#) are discarded. A line which does not start with a colon (:) or bar (|) starts a printer entry definition. Lines ending with a backslash (\) are assumed to continue to the next line; this is for compatibility with other historical printcap file formats. Trailing blanks and tabs (whitespace) for an option value are deleted unless the last one is escaped with a backslash (``\''). If a colon character value is required then the \: escape sequence can be used, e.g.: dest=ftp\://address/file.

A printer definition starts with a primary printer name, followed by zero or more alternative printer names, followed by a set of keyword entries and values. For example:

#comment # primary printer name lp #alternate names: |lp2|lp3
|Example of a printer
:sd=/usr/spool/LPD/lp
:rw:lp=/dev/lp:mx#100
include /etc/printcap/mainprintcap
The special printcap definition include will read the named file, which must have an absolute pathname, as the next set of printcap entries.
Keywords can be 1 to an indefinite number of characters long, and are case sensitive. Values for keywords can be strings (:st=string:), signed integer values using the C language notation, (:nu#12:max#-2:mask#0x1EF:), or flags (:flag: to set to 1, :flag@: to clear to 0). Integer values must be representable as 32 bit 2's complement numbers; care should be taken with extremely large numbers.
If the primary name of a printcap entry starts with a punctuation character, then the entry may be referenced using the tc capability, but is ignored otherwise. This allows common printcap information to be placed in a single entry.
The special printcap entry oh (i.e. - only this host) may be used to select a printcap entry for use by one or more hosts. The oh entry can be a list of one or more host names or glob type of patterns. These patterns are first applied to the host's fully qualified domain name, and then used to to a lookup of an IP address. If either the glob match or the host has a matching IP address then the printcap entry is selected for use. In addition, the server flag indicates that only the LPD server is to use this printcap entry. This allows client and server printcap information be to be segregated in a simple manner.
The following is a list of the keywords currently used by the LPRng software. Many of these keywords are used only by the LPD server, others are used by the client programs LPR, LPC, LPRM, PAC, as well as the server. In the Use column in the table below, an A stands for all programs, D stands for lpd, and R stands for the client programs such as LPR.
Some of these entries can only appear or have an effect if they are in the lpd.conf initialization file. See lpd.conf(5) for further details.

ENTRIES BY ALPHABETICAL ORDER

FL Use Type Default Description Xf D str NULL output filter for format X (used by lpd).: 'filter' sets default filter
ab D bool false always print banner, ignore lpr -h option achk D bool false: If TRUE LPD and the :as specifies a remote host or filter or the :af specifies a remote host or filter then after writing the accounting information to the destination a reply will be read. The value of the reply determines how the job is to be handled.
ae D str accounting format for end of job or a program to run: to record accounting information (see also af, la, ar and Accounting).
af D str NULL: accounting file, filter, or remote accounting server (see also la, ar, as, ae, achk). If format is |/path then the program will be started and accounting information will be written to the program STDIN. If the format host%port, a tcp/ip connection will be made to port on host and the accounting information written to the remote host. In both of these cases the write operation must succeed or an error will result. If the format is neither of these cases then the value will be treated as a file and accounting information appended to the file if it exists. The accounting file will not be created, it must exist for LPD to append data to it.
The :as and :ae fields have the accounting information.
ah D bool false auto-hold - job held until explicitly released all A str NULL a list of all printers; (see ALL PRINTERS) allow_duplicate_flags A bool false: allow duplicate command line flags; last overwrites earlier
allow_getenv A bool (compile time): allows LPRng software to use the LPD_CONF environment variable to specify the location of a configuration file. This is for testing only.
allow_user_logging A bool false: if mail is requested using lpr -mhost%port,prot operations, and the allow_user_logging flag is true, then job logging information will be sent to host%port,prot.
allow_user_setting A str NULL: allow these users to impersonate other users with the lpr -U user@host, lpc -U user@host, etc., options
append_z A str: append these options to the -Z options for the job
ar D bool true write remote transfer accounting (if af, and as/ae set) architecture A str (compile time): architecture the software was compiled for. (Obsolete.)
as D str accounting format for start of job or a program to run: to record accounting information (see also af, la, ar and Accounting).
auth R str NULL: client to server authentication type
be D str banner printing program for end (overrides bp, hl) bk R bool false Berkeley-compatible: be strictly RFC-compliant: or more exactly, BSD LPR compatible when sending jobs.
bk_filter_options D str (see source code): when bk flag set, options for non OF print filters
bk_of_filter_options D str (see source code): when bk flag set, options for OF print filters
bkf R bool false: use bk_filter_options and bk_of_filter_options when invoking print filter.
bl D str banner line - sent to banner printer program: default: $-'C:$-'n Job: $-'J Date: $-'t
expands to: Class:User Job: job Date: date
This is to force compatibility with vintage print filters that require a non-standard banner string. Usually used with :sb: option.
bp D str banner printing program (see hl): (default: configuration variable default_banner_printer)
bq_format D str l format of output from bounce queue filters br D num none if lp is a tty, set the baud rate (see ty) break_classname_priority_link A flag false: Do not set priority to first letter of class name
bs D str banner printing program for start (overrides bp, hl) cf D str NULL cifplot data filter check_for_nonprintable R bool false: lpr checks f and p formats for printable files
check_for_protocol_violations R bool false: check for RFC1179 protocol violations
chooser D str load balance queue destination chooser program chooser_interval D num 10: load balance queue does checks for a
destination queue available at this interval
chooser_routine D bool false: use the user provided chooser routine for this queue
class_in_status A bool true: show class name in lpq status rather than priority
cm A str NULL comment identifying printer (LPQ) config_file A str //etc/lprng/lpd.conf: location of LPRng configuration information. Compile time option only - see allow_getenv.
connect_grace A num 0: time between jobs to allow printer recovery
connect_interval A num 10: time between open or connection attempts
connect_timeout A num 10: timeout value for connection or open
control_file_line_order D str NULL: Put the control file lines in a specific order
control_filter D str NULL: Filter for control file. Used when sending job to remote spool queue.
create_files D bool false: create log, debug, etc., files automatically
db A str NULL LPD debug options when serving this queue.: See lf (log file) entry as well.
default_format R str f: default format for printing jobs
default_permission D str A: default permission for operation
default_printer A str lp: default printer for printing jobs
default_priority R str A: default priority for printing jobs
default_remote_host A str localhost: default remote host for printing operations
default_tmp_dir A str /tmp: default temporary directory
destinations D str NULL: names of printers that lpq/lprm should talk to find a job that has been processed by a router script (see README.routing)
df D str NULL tex data filter (DVI format) done_jobs D num 1: retain status for last N jobs
done_jobs_max_age num 0: remove status older than N seconds (0 - no removal)
exit_linger_timeout A num 10: socket SO_LINGER timeout value
fd D bool false if true, no forwarded jobs accepted ff D str ``\f'' string to send for a form feed (see INITIALIZATION) filter D str NULL: default filter to use for printing file
filter_ld_path D str (see source): the LD_LIBARY_PATH environment variable value for filters
filter_options D str (see source code): when bk flag clear, options for non OF print filters
filter_path D str (default '/bin:/usr/bin'): the PATH environment variable value for filters
filter_poll_interval D num 30: interval to poll OF filter
filter_stderr_to_status_file D bool false: set the filter STDERR to the status file and do no report errors in the queue status file.
fo D bool false print a form feed when device is opened force_fqdn_hostname A bool FALSE: Force a fully qualified host name in control file
force_ipadddr_hostname A bool FALSE: Force the IP address of the host to be used for the hostname in control file
force_localhost A bool TRUE: Forces the clients programs (lpr, lpc, etc.)
to send all print jobs and requests to the server running on the localhost entry for action. This flag effectively forces BSD LPR behavior.
force_lpq_status D str NULL: Specifies a list of LPQ formats and hosts which get status returned in this format. For example
force_lpq_status=s=pc*;l=mac* will cause hosts whose FQDN matches pc* to get short status and those which match mac* to get long format.
force_queuename A str NULL: When :qq: flag or use_queuename configuration is enabled, specifies the queuename to be used for control file Q information.
ff_separator D bool false: need form feeds to separate job files
fq D bool false print a form feed when device is closed full_time D bool detailed time format specification in log messages fx A str NULL valid output filter formats: i.e. ``flp'' would allow f, l, and p
default is to allow all formats
gf D str NULL graph data filter (plot (3X) format) generate_banner D bool false: generate a banner when forwarding job
group D str daemon LPD server group id for execution hl D bool false print banner after job instead of before if D str NULL filter command, run on a per-file basis ignore_requested_user_priority D bool false: Ignore the requested user priority when ordering jobs. Prevents students... um... users from queue jumping.
ipv6 A bool false Use IPV6 keepalive A bool true: set socket SO_KEEPALIVE option
kerberos_keytab D str /etc/lpd.keytab: Kerberos lpd server keytab file
kerberos_life D str NULL: Kerberos lpd server key lifetime
kerberos_renew D str NULL: Kerberos lpd server key renewal time
kerberos_server_principle D str NULL: Kerberos remote lpd server principle
kerberos_service D str lpr: Kerberos service used in principle requests
la D bool true write local printer accounting (if af is set) ld D str NULL leader string printed on printer open (see INITIALIZATION) lf D str ``log'' error and debugging log file (LPD) lk D bool false lock the lp device to force arbitration lockfile D str /var/spool/lpd/lpd: lpd lock file (used only in lpd.conf).
The lpd_port port value is appended to the lockfile value to provide a unique lockfile even when different versions of LPRng are running on the same system.
logger_destination D str NULL: destination for logging information. Format is host%port
logger_max_size D num 1024: logger file maximum size in K
logger_path D str NULL: logger file pathname
logger_timeout D num 0: logger connection timeout. 0 is no timeout.
longnumber D bool false: use 6 digit job numbers
lp D str NULL device name or pipe to send output to lpd_bounce A bool FALSE: Forces lpd to filter jobs and then forward them as a single file
(See Bounce Queues)
lpd_force_poll A bool FALSE: Forces lpd to periodically poll lpd queues.
lpd_poll_time A num 600: Check queues for work at this interval; start queues in groups of 'lpd_poll_servers_started' at intervals of 'lpd_poll_start_interval' seconds
lpd_poll_start_interval A num 10: Start 'lpd_poll_servers_started' queue servers at this interval.
lpd_poll_servers_started A num 10: Start 'lpd_poll_servers_started' queues at once
lpd_port D str printer: format is [ipaddr%]port. If the ipaddr is present
then the lpd listening socket is bound to the specified ip address and port only, otherwise it is bound to all interfaces. If the port value is not a number then the
then the getservbyname() system call is used to get the port number.; lpd_printcap_path D str (see source)
printcap path for lpd, used instead of printcap path (configuration value only); lpr_bounce R bool true
Forces lpr to filter jobs and then send them. (See Bounce Queues); lpr_bsd R bool false
when set, LPR -m will not take argument, but will use $USER value for return mail address.; mail_from D str NULL
specifies the user part of email From: address; mail_operator_on_error D str NULL
send mail to this user when LPD encounters printing error.; max_connect_interval A num 60
maximum time between connection attempts; max_log_file_size D num 0
maximum log file size in K bytes (0 is unlimited) spool queue log file truncated to min_log_file_size when value is nonzero and limited exceeded.; max_servers_active D num 0
maximum servers that LPD will allow to be active at one time. 0 selects the system default, which is usually pretty small, perhaps 10. (configuration value only).; max_status_line D num 79 maximum number of characters on an LPQ status line max_status_size D num 10 maximum size (Kbytes) of status file mc R num 1 maximum copies allowed
min_log_file_size D num 0 minimum size (Kbytes) of log file min_status_size D num 2 minimum size (Kbytes) of status file minfree D str 0
minimum space (in K) for spool directory; ml R num 32 minimum printable characters for printable check ms_time_resolution D bool false
log time in milliseconds; mx R num 0 maximum job size in K, 0 = unlimited
nb D num 0 if non-zero, do a nonblocking open on lp device nf D str NULL DITROFF data filter
network_connect_grace A num 0
time between attempts to send jobs to spooler Useful when dealing with network printer using LPD interface to allow a bit of time between jobs.; nline_after_file D bool false
put the N (filename) after the data file information in the control file. Use to handle systems that want it that way.; of D str NULL output filter, run once for all output
(used for banner printing, form feeds between files); of_filter_options D str (see source code)
when bk flag clear, options for OF print filters; oh A str NULL Specific printcap entry for host;
(printcap entry ignored unless IP address of host and entry value match. Entry is used first to do glob style match against the host's fully qualified domain name, and then interpreted as a general IP address); order_routine D bool false
use a user provided routine to generate queue order information.; originate_port A str 512 1023
when originating a connection, use ports in this range.; pass_env A str PGPPASS,PGPPATH
if not the LPD server, sanitize and put these variables in a filter environment variable list.; perms_path A str //etc/lprng/lpd.perms
location of perms file (used in lpd.conf); pl D num 66 page length (in lines)
pr D str ``/bin/pr'' pr program for p format
prefix_o_to_z D bool false
prefix the control file O line to the control file Z line.; prefix_z D str NULL
prefix the specified options to the control file Z line.; prefix_z_to_o D bool false
prefix the control file Z line to the control file O line.; printcap_path A str //etc/printcap
location of printcap file (only in lpd.conf); ps A str ''status'' printer status file name
pw D num 132 page width (in characters)
px D num 0 page width in pixels (horizontal)
py D num 0 page length in pixels (vertical)
qq A bool false LPR - puts in the queue name (Q entry)
in the job control file when spooled or transferred. LPD - when receiving or transferring a job,
if the queue name (Q entry) in the job control file is not present, puts in the queue name.; queue_control_file D str control.%P
name of the queue control file; queue_lock_file D str %P
name of the queue lock file; queue_status_file D str status.%P
name of the queue status file; queue_unspooler_file D str unspooler.%P
name of the queue unspooler status file; remote_support A str NULL
if non-null, specifies allowed operations to remote queue. R=lpr, M=lprm, Q=lpq, V = lpq -v, C=lpc. For example, remote_support=RM would only allow LPR and LPRM operations.; remove_z D str null
remove these options from the control file Z line; report_server_as A str NULL
use the str value as the name of the server when reporting LPQ or LPC status.; require_explicit_q Require a queue to be specified, do not use default
queue from printcap.; retry_econnrefused A bool true
if set, retry a connection to a remote system when an ECONNREFUSED error is returned.; retry_nolink D bool true
if LPD is sending a job or opening a device for printing and the value is true, then the connection or device open is repeated indefinitely.; return_short_status D str NULL
Some legacy (non-LPRng) LPQ programs expect 'short' status to be returned. This option allows you to specify which hosts will get it. The value is a list of hosts and/or IP addresses and masks to which the LPD server will provide short status. For example: return_short_status=192.8.0.0/16 will make LPD return short status to all requests from hosts in subnet 192.8.0.0. (See short_status_length); reuse_addr A bool false
if set, use SO_REUSEADDR on outgoing connection ports. This reduces the problems with exhausting port numbers. (usually only in lpd.conf); reverse_lpq_status D str NULL
When a lpq status request arrives from one of the specified hosts or IP addresses, then the LPQ status format is inverted. For example, if reverse_lpq_status=host*,127.0.0.0/8, then when a LONG status request arrives from host1 or from IP address 127.0.0.1, the SHORT status will be returned.; reverse_priority_order D bool false
Make highest priority A, lowest Z; rf D str NULL filter for printing FORTRAN style text files
rg A str NULL (restrict to group members)
Restrict use of queue to users which are members of specified groups.; rm A str NULL remote-queue machine (hostname) (with rp)
router D str NULL script that dynamically re-routes a job
(see README.routing); rp A str NULL remote-queue printer name (with rm)
rw D bool false open the printer for reading and writing
safe_chars D str NULL
additional safe characters for control file contents; save_on_error D bool false
Save job when an error occurs to allow post-mortem diagnostics or reprinting. This should only be set on print queues. It is also a diagnostic aid.; save_when_done D bool false
Save job when done (printed, transferred) to allow retry at a later time. This should only be set on print queues. It is also a diagnostic aid.; sb D bool false short banner (one line only)
sd A str NULL spool directory (only ONE printer per directory!) send_block_format A bool false
Use the LPRng extended 'block job' job transmission method to send a job to a remote site.; send_data_first A bool false send data files then control files
when sending a job to a remote host.; send_failure_action D str "remove"
Action on print or transmission failure after send_try attempts; use the following codes:
'success' (JSUCC) - treat as successful
'abort' (JABORT) - abort printer
'retry' (JRETRY) - retry job
'remove' (JREMOVE)- remove job
'hold' (JHOLD) - hold job
If the value is "|/filter", the filter will be run and the number of attempts can be read from standard input. The filter should exit with one of the error codes listed above to cause the appropriate action.; send_job_rw_timeout A num 6000
timeout on read/write operations when sending job to printer or remote host (0 value is no timeout); send_query_rw_timeout A num 6000
timeout on read/write operations when performing a status operation (0 value is no timeout); send_try A num 3
number of times to try sending
or printing a job. 0 is infinite.; sendmail D str /usr/sbin/sendmail -oi -t
sendmail command to send mail to user. Flags must be set so that address and other information is taken from standard input.; server A bool false printcap entry for server only
server_auth_command A str NULL
authentication command for server program; server_tmp_dir D str /tmp
temporary directory for server to create files when there is no spool directory.; server_user D str daemon server user name used in authentication operations sf D bool true suppress form feed separators between job files sh D bool false suppress headers and/or banner page
shell D str /bin/sh
SHELL environment variable value for filters; short_status_length D num 1
If the return_short_status value is used and has a match against a requesting address, this amount of status is set by the short_status_length option. For most legacy systems a 1 is suitable (1 line of status).; socket_linger A num 10
if nonzero, forces a SO_LINGER operation to be done on all TCP/IP connections. This usually corrects a problem with missing last data transmissions to remote hosts.; spool_dir_perms D num 042700 permissions for spool directory spool_file_perms D num 0600 permissions for spool file
ss D str NULL name of queue that server serves (with sv)
ssl_XXX D str NULL
SSL authentication and encryption options.
See lprng_certs(1) for details.; ssl_ca_file str A //etc/lprng/ssl.ca/ca.crt
SSL signing certificate file; ssl_ca_path str A NULL
SSL signing certificate directory. Default is directory containing ssl_ca_file.; ssl_server_cert str A //etc/lprng/ssl.server/server.crt
SSL server certificate; ssl_server_password str A
SSL server certificate password; stalled_time D num 120
Time after which to report an active job as stalled; stop_on_abort D bool true
Stop processing queue when print filter aborts.; stty D str NULL stty settings for serial connected printer suspend_of_filter D bool true
suspend OF filter and restart. If false, close filter and start new one for each activity.; sv D str NULL names of servers for queue (with ss)
syslog_device D str /dev/console
name of syslog device to use if no syslog facility; tc A str NULL reference to a printcap entry to include as part of
the current entry.; tf D str NULL troff data filter (C/A/T phototypesetter)
tr D str NULL trailer string to print when queue empties
translate_format D str NULL
translate job format (similar to tr(1) utility) on outgoing jobs.
Example: translate_format=pfml
p format changed to f, m format to l; translate_incoming_format D str NULL
translate job format (similar to tr(1) utility) on incoming jobs. See translate_format.; use_date A bool true add date line ('D') to control file use_identifier R bool true
add job identifier lines ('A') in the control file; use_info_cache D bool true cache printcap information use_shorthost R bool false
use only the hostname for job control
and data file names. Host information in job file will still be fully qualified domain name.; user D str daemon LPD effective user (EUID) for SUID operations wait_for_eof D bool true
wait for EOF on input when readable IO device, do not close immediately at job end.; vf D str NULL (Versatek) raster image filter

ENTRIES BY FUNCTION

See the alphabetical listing for detailed information.

Filters and Page Formats
Xf D str NULL output filter for format X (used by lpd): 'filter' sets default filter
cf D str NULL cifplot data filter control_filter D str NULL: Filter for control file. Used when sending job to remote spool queue.
df D str NULL tex data filter (DVI format) direct_read D bool false: if true, filters are given direct access to file. This means no progress indication possible.
fx A str NULL valid output filter formats: i.e. ``flp'' would allow f, l, and p
default is to allow all formats
gf D str NULL graph data filter (plot (3X) format) if D str NULL filter command, run on a per-file basis lpd_bounce R bool false: Forces lpd to filter jobs and then forward them. (See Bounce Queues)
lpr_bounce R bool false: Forces lpr to filter jobs and then send them. (See Bounce Queues)
nf D str NULL DITROFF data filter of D str NULL output filter, run once for all output pl D num 66 page length (in lines) pr D str ``/bin/pr'' pr program for p format pw D num 132 page width (in characters) px D num 0 page width in pixels (horizontal) py D num 0 page length in pixels (vertical) rf D str NULL filter for printing FORTRAN style text files translate_format D str NULL: translate job format (similar to tr(1) utility) only valid when transferring to remote spool queue. Example: translate_format=pfml
p format changed to f, m format to l
tf D str NULL troff data filter (C/A/T phototypesetter) vf D str NULL (Versatek) raster image filter
Banners
ab D bool false always print banner, ignore lpr -h option
be D str banner printing program for end (overrides bp, hl) bp D str banner printing program (use hl to print banner at end) bs D str banner printing program for start (overrides bp, hl) hl D bool false print banner after job instead of before
sb D bool false short banner (one line only)
sh D bool false suppress headers and/or banner page, overrides ab
Accounting
ae D str accounting format for end of job or a program to run: to record accounting information (see also af, la, ar
and Accounting).; af D str NULL name of accounting file (see also la, ar)
ar D bool true write remote transfer accounting (if af, and as/ae set) as D str accounting format for start of job or a program to run
to record accounting information (see also af, la, ar
and Accounting).

la D bool true write local printer accounting (if af is set)

Queue control
ah D bool false auto-hold - job held until explicitly released bk R bool false backwards-compatible: be strictly RFC-compliant bkf R bool false backwards-compatible filter: use Berkeley filter options bqfilter D bool false if a bounce queue (sends jobs to remote site)

then when bqfilter true and a format filter is specified, sends data files through format filter before transfer. See also 'qq'.

cd D str NULL control information directory for LPD server
cm A str NULL comment identifying printer (LPQ)
fd D bool false if true, no forwarded jobs accepted
lf D str ``log'' error and debugging log file (LPD)
longnumber D bool false

use 6 digit job numbers

mc R num 1 maximum copies allowed
ml R num 32 minimum printable characters for printable check minfree D str 0 minimum space (Kb) to be left in spool filesystem

You can also use nnnM for nnn megabytes.

mx R num 0 maximum job size (1Kb blocks, 0 = unlimited)
ps A str ''status'' printer status file name
nw A bool false spool dir is on an NFS file system

(take precautions when reading/writing files)

qq A bool false place queue information in control file. See

alphabetical for details.

rm A str NULL remote-queue machine (hostname) (with rp)
rp A str NULL remote-queue printer name (with rm)
sd A str NULL spool directory (only ONE printer per directory!) ss D str NULL name of queue that server serves (with sv)
sv D str NULL names of servers for queue (with ss)
sc R bool false suppress multiple copies
use_auth A str NULL authentication to use
use_date A bool true add date line ('D') to control file use_identifier R bool true

add job identifier lines ('A') in the control file

use_shorthost R bool false use only the hostname for job control

and data file names. Host information in job file will still be fully qualified domain name.
Connection and Interface to Printer db A num 0 debug level when using this printer
connect_interval A num 10: time between open or connection attempts
connect_timeout A num 10: timeout value for connection or open
(0 is infinite number)
ff D str ``\f'' string to send for a form feed (see INITIALIZATION) fo D bool false print a form feed when device is opened fq D bool false print a form feed when device is closed ld D str NULL leader string printed on printer open (see INITIALIZATION)
lp D str NULL device name or pipe to send output to lk D bool false lock the lp device to force arbitration max_connect_interval A num 60: maximum time between connection attempts
nb D num 0 if non-zero, do a nonblocking open on lp device retry_econnrefused A bool true: if set, retry a connection to a remote system when an ECONNREFUSED error is returned.
retry_nolink D bool true: if LPD is sending a job or opening a device for printing and the value is true, then the connection or device open is repeated indefinitely.
rs D num 300 number of seconds between spool queue status scans rt D num 3 number of times to try printing (0=infinite). rw D bool false open the printer for reading and writing save_on_error D bool false: See above.
save_when_done D bool false: See above.
send_failure_action D str remove: See above.
send_try alias for rt sf D bool true suppress form feed separators between job files socket_linger A num 10: if nonzero, forces a SO_LINGER operation to be done on all TCP/IP connections. This usually corrects a problem with missing last data transmissions to remote hosts.
tr D str NULL trailer string to print when queue empties
Serial Line Setup
br D num none if lp is a tty, set the baud rate (see ty)
stty D str NULL stty commands to set output line characteristics: alias is sy, ms
xs D num 0 like `xc' but set bits (see STTY)
Miscellaneous
all A str NULL a list of all printers; (see ALL PRINTERS)
destinations D str NULL: names of printers that lpq/lprm should talk to find a job that has been processed by a router script (see README.routing)
forward_auth D str NULL: server to server authentication type, e.g. pgp, kerberos
force_localhost A bool TRUE: Forces the clients programs (lpr, lpc, etc.)
to send all print jobs and requests to the server running on the localhost entry for action. This flag effectively forces BSD LPR behaviour.
force_queuename A str NULL: See above.
logger_destination D str NULL: destination for logging information. Format is host[%port][,(TCP|UDP)]
oh D str NULL Specific printcap entry for host. See above. remote_support A str RMQC: if non-null, specifies allowed operations to remote queue. R=lpr, M=lprm, Q=lpq, C=lpc
router D str NULL script that dynamically re-routes a job: (see README.routing)
server A bool false printcap entry for server only server_auth_command D str NULL: authentication command for server to use.
tc A str NULL reference to a printcap entry to include as part of: the current entry.
use_auth D str NULL: client to server authentication type, e.g. pgp, kerberos
user_auth_command R str NULL: authentication command for user (client program)

FILTERS

By convention, all output filter names have the form Xf, where X is the lower case letter corresponding to the lpr formatting option. The filter option can specify a default filter for job files.

The of filter is started for each job and is used to print the banner page and any FF separators between individual files of the job. It is sent a special stop sequence by the lpd server, and must suspend operations until sent a SIGCONT signal. A file or job filter is run separately for each file; at the end of the job the of filter is restarted and used to print the trailing banner (if any) and FF separators.

Filters are invoked with a standard set of options defined by the bk_filter_options (backwards compatible), bk_of_filter_options (backwards compatible OF filter), and filter_options configuration variables. See the lpd(8) manual page for details. If the first characters of the filter specification are -$, i.e.- Xf=-$ filter, then the command line options are not added. Currently, the options are: bk_filter_options $P $w $l $x $y $F $c $L $i $J $C $0n $0h $-a bk_of_filter_options $w $l $x $y filter_options $C $F $H $J $L $P $Q $R $Z $a $c $d \: $e $f $h $i $j $k $l $n $s $w $x $y $-a

SPOOL QUEUES

Printcap entries which have a spool directory value (sd) are called spool queues. Jobs sent to a printer with a spool queue are place in the spool directory. When checking the spool queue for jobs, the server will check to see if there is a printcap file in the directory with the name printcap.host. If there is, the additional printcap information is processed and used by the server.

If the spool directory is NFS exported, then remote hosts can manipulate the spool entries directly; this can have catastrophic effects, especially in systems where the NFS implementation has defects. The printcap information is particularly vulnerable to exploitation, as well as symbolic links, jobs which cannot be removed, etc.

LOCAL PRINTERS

Local printers have an lp entry, which is the device that output should be sent to, usually a serial port tty. PLP supplements this by using the lp field to indicate a remote printer, or by allowing communication with the printer using a separate program, known as an lp-pipe, instead of a serial line. If the printcap lp entry contains a string of the form printer@host, jobs are forwarded to the specified remote printer on the host. If the printcap lp entry contains a string of the form | command args , the command command is run, with the arguments args . This can be used to communicate with printers connected to network terminal servers, some TCP/IP-capable printers, and just about anything you can hack up a communication program for. Read the LPRng Manual for more details.

STTY OPTIONS

The stty printcap parameter recognizes a set of stty(1) options that can be used to set serial line characteristics for the printer. However, due to the differences between implementations of UNIX, there are several sets of ty options supported. Invoke lpd(8) with the ``-v'' command-line option to see which set your installation is using.

Systems using the sgtty tty manipulation interface may use the following stty(1) options:

bs0 bs1 [-]cbreak cooked cr0
cr1 cr2 cr3 [-]decctlq [-]echo [-]even ff0 ff1 [-]lcase [-]litout nl0 nl1 nl2 nl3 [-]nl
[-]noflsh new [-]nohang old [-]odd [-]raw start stop tab0 tab1
tab2 [-]tabs [-]tandem tek ti700
[-]tilde tn300 tty33 tty37 vt05
[-]evenp [-]oddp [-]pass8

Systems using termio may use the following options:

[-]ignbrk [-]brkint [-]ignpar [-]parmrk [-]inpck [-]istrip [-]inlcr [-]igncr [-]icrnl [-]iuclc [-]ixon [-]ixany [-]ixoff [-]decctlq [-]tandem [-]imaxbel [-]opost [-]olcuc [-]onlcr [-]ocrnl [-]onocr [-]onlret [-]ofill [-]ofdel [-]cstopb [-]cread [-]parenb [-]parodd [-]hupcl [-]clocal [-]loblk [-]parity [-]evenp [-]oddp [-]stopb [-]hup [-]crtscts [-]isig [-]noisig [-]icanon [-]cbreak [-]xcase [-]echo [-]echoe [-]echok [-]crterase [-]lfkc [-]echonl [-]noflsh [-]tostop [-]echoctl [-]ctlecho [-]echoprt [-]prterase [-]echoke [-]crtkill [-]lcase [-]nl [-]litout [-]pass8 [-]raw [-]sane [-]cooked [-]nopost fill
nl0 nl1 cr0 cr1 cr2
cr3 tab0 tab1 tab2 tab3
bs0 bs1 vt0 vt1 ff0
ff1 cs5 cs6 cs7 cs8
nul-fill del-fill -tabs

And systems using termios may use the following options:

[-]ignbrk [-]brkint [-]ignpar [-]parmrk [-]inpck [-]istrip [-]inlcr [-]igncr [-]icrnl [-]iuclc [-]ixon [-]ixany [-]ixoff [-]imaxbel [-]pass8 [-]opost [-]olcuc [-]onlcr [-]ocrnl [-]onocr [-]onlret [-]ofill [-]ofdel [-]tabs nl0
nl1 cr0 cr1 cr2 cr3
tab0 tab1 tab2 tab3 bs0
bs1 vt0 vt1 ff0 ff1
cs5 cs6 cs7 cs8 [-]cstopb [-]cread [-]parenb [-]parodd [-]hupcl [-]clocal [-]crtscts [-]evenp [-]parity [-]oddp [-]pass8 [-]isig [-]icanon [-]xcase [-]echo [-]echoe [-]echok [-]echonl [-]noflsh [-]tostop [-]iexten [-]echoctl [-]ctlecho [-]echoprt [-]prterase [-]echoke [-]crtkill [-]flusho [-]pendin

The fc , fs , xc , and xs printcap entries are obsolete, and if present with non-zero values will abort print job processing.

INITIALIZATION

Many printers require an initialization string to be sent to them in order to configure their operation. The leader (ld) and trailer (tr) strings are sent at the start and end of job processing. These strings are interpreted using the C language conventions for character representation: \nnn is replaced with a character with the value nnn, \n with a new line, \r with a carriage return, and so forth.

ALL PRINTERS

The LPRng software has the capability to use a remote database for obtaining printcap and other information. One of the difficulties arises when a list of all printers available is needed. By convention, the special printer name all is reserved for this information; the all field is a list of printers separated by spaces or punctuation. For example:

#all printers
all:all=lp1,lp2,lp3,lp4

ACCOUNTING

Accounting in the LPRng package has evolved over time to accommodate new requirements. The general approach is to use either a simple log to file method in which the accounting information is written to a log file or a more complex log to program method in which the accounting information is written to a program. The information and method and actions taken are specified by the following entries:
:as - start of job accounting
:ae - end of job accounting
:af - default job accounting
:achk - used accounting for authorization.

The value of the :as and :ae options are either a string which is used as the accounting information or a program which is executed to log or save the accounting information. If a program is executed then the value of the :af entry is ignored and the program is run to record the job accounting information. For example:
# string for information logging
:as=jobend $H $n $P $k $b $t
:ae=jobstart $H $n $P $k $b $t

:as=|/usr/local/libexec/logjobstart $H $n $P $k $b $t
:ae=|/usr/local/libexec/logjobend $H $n $P $k $b $t

If the :as or :ae value is a string then the :af information is used to record the accounting information: af=|/path - run program, :as or :ae written to: program STDIN
af=host%port - tcp/ip connection to port on host,: :as or :ae written to connection
af=path - treat path as a file pathname,: if file exists append :as or :ae
to file.
If the :achk flag is set then this is modified as follows. If the :as entry specifies a program or :af entry specifies a program or remote host (i.e. - logging using program) then after accounting information has been written to the program or connection a response will be read from the program STDOUT or the connection. This response is expected to be an ASCII string. If the line is blank or starts with ACCEPT then the job will be printed, HOLD will hold the job, REMOVE will remove the job, and ABORT or a non-recognizable response will cause printing to be aborted.
If the output is written to a program then the exit status of the program can be used as well. If the program exits with nonzero status then the exit code controls the disposition: JHOLD, JREMOVE, and JABORT will hold, remove, or abort the job respectively. If the exit status is 0, then the filter's STDOUT will be read and processed as described above.

BOUNCE QUEUES AND PRINT FORMATS

If the lp option value has the format :lp=pr@host or job forwarding is specified by :rp=pr:rm=host then the normal operation is simple to store and forward the print jobs. If filters are specified then the job files are first filtered and then the output of the filters is sent to the destination. For historical reasons, a spool queue that does filtering and forwarding is called a bounce queue. The bounce_queue_format (default 'f') specifies the output for the filtered files. If this is not desirable the translate_format option can be used to specify a format. The option has the form SdSdSdN, where S is the original format and d is the final format. If none of the formats match and there is an odd number of formats then the last one is used. For example, pfmlf would convert formats p to f, m to l, and v to f.

The :lpd_bounce flag concatenate the output of the filters and the result will be sent as a single job file to the destination. This facility is useful when handling legacy print spooler applications that do not understand the RFC1179 copy, etc., options. The first letter of the bounce_queue_format (default 'f') is used as the output file format.

The lpr_bounce printcap flag can be used to cause LPR to do bounce queue filtering in exactly the same manner as the server. This should be used with caution as missing filters on the client system can cause unexpected behavior.

KERBEROS, PGP, AND OTHER AUTHENTICATION METHODS

LPRng supports built in kerberos authentication. To enable this, the LPD protocol has been extended to provide a way to transfer authenticated and/or encrypted jobs and commands. The details are covered in the LPRng HOWTO documentation.

Also, SSL can be used. See lprng_certs(1) for details.

FILES

The files used by LPRng are set by values in the printer configuration file. The following are a commonly used set of default values.
//etc/lprng/lpd.conf LPRng configuration file
${HOME}/.printcap user printer description file //etc/printcap printer description file
//etc/lprng/lpd.perms permissions
/var/run/lprng/lpd lock file for queue control /var/spool/lpd spool directories
/var/spool/lpd/QUEUE/control queue control
/var/spool/lpd/QUEUE/log trace or debug log file
/var/spool/lpd/QUEUE/acct accounting file
/var/spool/lpd/QUEUE/status status file

AUTHOR

Patrick Powell <papowell@lprng.com>.

DIAGNOSTICS

Most of the diagnostics are self explanatory. If you are puzzled over the exact cause of failure, set the debugging level on (-D5) and run again. The debugging information will help you to pinpoint the exact cause of failure.

HISTORY

LPRng is a enhanced printer spooler system with functionality similar to the Berkeley LPR software. The LPRng developer mailing list is lprng-devel@lists.sourceforge.net; subscribe by visiting https://lists.sourceforge.net/lists/listinfo/lprng-devel or sending mail to lprng-request@lists.sourceforge.net with the word subscribe in the body.
The software is available via http://lprng.sourceforge.net

docs.sk

comprehensive documentation repository

See also