LPD.CONF(5)

NAME
lpd.conf - configuration file for the LPRng line printer spooler system

DESCRIPTION
The file lpd.conf is used to provide configuration information for the LPRng Printer spooler system and defaults for printcap information. Leading spaces on lines are ignored, and blank lines and lines whose first nonblank character is a sharp (``#'') are ignored. Trailing blanks and tabs (whitespace) for an option value are deleted unless the last one is escaped with a backslash (``\''). All other lines specify parameters and should be of the following form:
    keyword
    keyword@
    keyword#value
    keyword=value
Note that these values are the same format as printcap(5) values. Values in the configuration can contain host or machine dependent information; to assist with this, the following escape sequences in the configuration information are replaced as follows:

%h  the short form of the host name (i.e.- non fully qualified).

%H  the fully qualified host name.

%a  the abbreviated architecture name, sun4, sol2, hpux, aix, irix5, etc. This value can be set using the architecture keyword in the configuration file and is set to a default value at compile_time.

%P  the printer name from the printcap entry (see below).

%R  the remote printer name from the printcap entry.

%M  the remote host name from the printcap entry. This is truncated to the short host name.

For example, on host dickory.sdsu.edu, the strings short=%h long=%H arch=%a would be expanded as short=dickory long=dickory.sdsu.edu arch=sun4 .

The P, R, and M tags are provided for use with combined configuration and printcap information. These values are not expanded when the printcap information is initially processed, and can be used only in a limited number of printcap or other entries. Currently only the printcap :sd: (spool directory) and :forward_server: (forward server) entries use these.

GENERAL CONFIGURATION PARAMETERS

Some of the following parameters take lists of files or directories. Unless otherwise explicitly stated, these lists can be separated by commas (,), semicolons (;), or colons, (punctuation) and possibly tabs or spaces (whitespace) as well.

Keyword names can use either underscores (_) or hyphens (-) in their names, but the underscore is preferred.

include pathname [pathname*] (no default)
    This can be used to include files into the lpd.conf file. The include file parameter a whitespace separated list of files; the files must have absolute pathnames and must be readable.

ae (default: "jobend $H $n $P $k $b $t")
    This specifies either a script or a filter to be invoked at the send of a job for accounting purposes. See as for the matching accounting at start, and the printcap(5) and lpd(8) man pages for details.

allow_getenv (default: "LPD_CONF")
    This option specifies an environment variable whose value is a configuration file. Use of this is restricted to test purposes, and SUID ROOT client and server will not run when the variable is enabled.

ar (default: yes)
    See printcap(5) for details.

architecture
    The default value is set at compile time and can be overwritten with this parameter. The default value of this parameter is set at compile time and it is used when expanding the special sequence %a in pathname and filename strings in this config file.

auth (default: NULL)
    Authentication type to be used for client to server communication.

auth_client_filter (default: NULL)
    Program to be used for client to server communication.

auth_forward (default: NULL)
    Authentication type to be used for server to server communication.

auth_forward_filter (default: NULL)
    Program to be used for server to server communication.

auth_forward_id (default: NULL)
    Authentication id of remote server for server to server communication.

auth_receive_filter (default: NULL)
    Program to be used by server receive server or client communication.

auth_server_id (default: NULL)
    Authentication id of originating client or server.

as (default: "jobstart $H $n $P $k $b $t")
    See as.

bk (default: no)
    See printcap(5) for details.

bk_filter_options
    (default: "$P $w $l $x $y $F $c $L $i $J $C $0n $0h $-a") If the "bkf" (backwards compatible filter) flags is set in the printcap entry and the original filter specification does not have a `$` in it, this option string is appended to a filter specification, and the string expanded with values from the printcap information and job information. (see of_filter_options, filter_options, bk_filter_options, bk_of_filter_options)

bk_of_filter_options
    (default: "$w $l $x $y") If the "bkf" (backwards compatible filter) flags is set in the printcap entry and the original filter specification does not have a `$` in it, this option string is appended to the OF filter specification, and the string expanded with values from the printcap information and job information. (see of_filter_options, filter_options, bk_filter_options, bk_of_filter_options)

check_for_nonprintable (default: "")
    (Used by LPR) check f and p formats for non_printable characters unless -b (binary) or -l (literal) command_line option is supplied. Note that files containing HPGL or other printer control languages would often be classed as ``non_printable''.

connect_grace (default: 0 seconds)
    The time to pause before opening a new connection to a printer. This allows the printer time to recover from the previous job.

connect_interval (default: 10 (seconds))
    The time to pause after a failed connection or open of the printing device before attempting a new connection or open.

connect_timeout (default: 10 (seconds))
    The time to wait for a device open or connection to complete. A zero value is infinite timeout.

retry_nolink (default: true)
    When TRUE and the LPD server is printing or transferring a job, then an indefinite number of attempts to connect to or open the IO device will be made.

default_banner_printer (default: "")
    The default banner printer program to be used for printing banners. This should be specified in the LPD configuration file.

default_format (default: "f")
    Default format for printing jobs.

default_logger_port
    (default: 2001) specifies a default port number for logger information. See logger_destination for details.

default_logger_protocol
    (default: UDP) specifies a default protocol for logger information. See logger_destination for details.

default_permission (default: ACCEPT)
    Default permission for operations.

default_printer (default: "")
    The default printer to use if there is no PRINTER environment variable, the user has not specified a printer, or there is no printcap information.

default_priority (default: "A")
    Default priority (class) for printing jobs. This is also used as the job class.

default_remote_host (default: "%H")
    The default remote host to use.

default_tmp_dir (default: /tmp)
    Directory for temporary files.

domain_name (default: "")
    This parameter is optional, and is appended to the hostname to make it into a fully_qualified domain name, ie. class.iona.ie. It will only be used if the software cannot determine the domain name using other means, such as gethostbyname(3n).

ff (default: \f)
    Formfeed string.

filter_ld_path
    (default: ) The value for the environment variable LD_LIBRARY_PATH, both used when executing, and passed on to filters. This variable is used to find shared libraries on SunOS, Solaris and Linux.

filter_options
    (default: "$C $F $H $J $L $P $Q $R $Z $a $c $d $e $f $h $i $j $k $l $n $p $r $s $w $x $y $-a") If the "bkf" (backwards compatible filter) flags is not set in the printcap entry and the original filter specification does not have a `$` in it, this option string is appended to a filter specification, and the string expanded with values from the printcap information and job information. (see of_filter_options, filter_options, bk_filter_options, bk_of_filter_options)

filter_path
    (default: /bin:/usr/bin:/usr/local/bin) The value for the environment variable PATH, both used to find filters and passed on to filters run by lpd and lpr.

force_poll (default: no)
    Some software packages put print jobs directly into the spool queues. The force_poll flag forces lpd to periodically poll spool queues looking for jobs and no server. The poll_time variable sets the interval between polls.

full_time (default: no)
    Use full time and date format in logging and error messages.

fx (default: "")
    See printcap(5) for details. This specifies the job formats allowed for this queue.

group (default "daemon")
    The group to use for file ownership and process permissions. Used only by lpd; this can be the name of a group or a number. All filters will run as the specified group. Note that if the group value is 0, then the real user group of the process at startup will be used.

kerberos_keytab (default "/etc/lpd.keytab")
    The keytab file to be used by the LPD server when using built-in kerberos authentication. The keytab file should be owned by the LPD server, and be readable/writable only by it (i.e. - 600 permissions).

kerberos_life (default NULL)
    The lifetime of a Kerberos ticket. NULL selects the default lifetime. Time should be specified using the standard Kerberos time representations.

kerberos_forward_principal (default NULL)
    remote principal used by server when forwarding

kerberos_renew (default NULL)
    The renewal of a Kerberos ticket. NULL selects a non-renewable ticket. Time should be specified using the standard Kerberos time representations.

kerberos_server_principal (default "lpr")
    Server principal used when client sending to server or when server is originating connection to another server for forwarding.

kerberos_service (default "lpr")
    The service name used to make requests to the LPD server when using kerberos authentication. For example, if kerberos_service has the value lpr, the server is on host alpha.com, and the kerberos domain is ALPHA.COM, then the kerberos principal name would be:
    lpr/alpha.com@ALPHA.COM.

la (default: yes)
    See printcap(5) for details.

lf (default: log)
    Name of the log file.

lo (default: lock)
    Name of the lock file.

localhost
    (default "localhost") The name of the localhost entry to be used for the TCP/IP loopback interface. The TCP/IP connection may originate from the local host; use this name to check to see if the local host address is in the IP address database, and use it as the origination address for local connections. This is done to avoid problems with multi-homed hosts who originate connections from different interfaces.

lockfile (default: /var/spool/lpd/lpd)
    The file used to indicate the presence of an lpd server running on the host. The lpd_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
    (default: "") This specifies a destination for logger information generated by the lpd server. The formation of the destination specification is host[%port][,(TCP|UDP)]. For example, localhost%2001,UDP would send logger information to the localhost IP address, on port 2001 using the UPD protocol. The default port and protocol are set by the default_logger_port and default_logger_protocol configuration variables respectively.

longnumber
    (default: no) RFC1179 requires 3 digit job numbers; setting longnumber to yes allows 6 digit numbers. If the backwards_compatible flag is set, only 3 digit numbers will be used.

lpd_listen_port (default: =off) [ipaddr%]port
    The port that lpd binds to. If the parameter is set to off then lpd does not listen to any TCP port. See lpd_port for details of the format of the argument.

    If this is not set at all, then lpdP will listen on lpd_port.

lpd_port (default: printer)  [ipaddr%]port
    The port that lpr and the other client programs send their requests to. The specification has the format ipaddr%port. If the IP address is specified then a bind to only this address and port is done. If the port value is not a number a service lookup is performed and the corresponding service port is used; see services(5). This parameter is useful for debugging a new installation of LPRng, in that running LPRng on a different port from the default will not interfere with a previous installation of LPD or LPRng.

lpd_printcap_path (default: "")
    The location of lpd server only printcap database information. If this is nonblank the printcap_pathP will not be used by the lpd server.

mail_operator_on_error (default: "")
    Put this person on the CC-list of the mail, if it is not a success mail. (So in addition to the person who made the printer request, also this person gets error messages, but no success messages.)

max_status_line (default: 79)
    An integer value specifying the numbers of characters to be used for displaying simple job status; this includes the queue position, job identifier, job contents, size, and time. A 0 (zero) value indicates no restrictions.

max_status_size (default: 10 (Kbytes))
    An integer value specifying (in K bytes) the maximum size of the status file to be generated during printing operations. A 0 value will create unlimited size status files. When the file size exceeds this value, it is truncated to min_status_size K bytes.

mc (default: 1)
    See printcap(5) for details.

min_status_size (default: 0 (Kbytes))
    Minimum status size. If 0, defaults to 20 percent of max_status_size.

minfree (default: 0)
    The amount of free space (in Kbytes) needed in the spool directory in order for a job to be accepted. If 0, there is no limit; if the parameter is the name of a file rather than a number, the file must contain a numerical minimum free value (in Kbytes). This value is overridden by the printcap mi field value.

ms_time_resolution
    (default: FALSE) This flag causes the time information to be printed to millisecond accuracy. This is overkill for most purposes.

of_filter_options
    (default: "") If this is not set, the value defaults to the same as the filter_options value. This string is appended to a OF filter specification, and the string expanded with values from the printcap information and job information. If the "bkf" (backwards compatible filter) flags is set in the printcap entry, of bk_of_filter_options value is appended instead (see of_filter_options, filter_options, bk_filter_options, bk_of_filter_options)

originate_port
    (default: "721 731") A range of port numbers to originate requests from. When sending service requests, the software will try to open and bind to these ports to originate a request to a server. If no port is given, or all of the requested ports are unavailable or cannot be bound to, then a normal use port is requested. Note that on UNIX systems, if a port in the range 0-1023 is requested the EUID of the process must be root for the request to be granted. Note that RFC1179 specifies that requests must originate from ports in the range 721-731.

pass_env
    (default: "LANG,LC_CTYPE,LC_NUMERIC,LC_TIME,LC_COLLATE,LC_MONETARY, LC_MESSAGES,LC_PAPER,LC_NAME,LC_ADDRESS,LC_TELEPHONE,LC_MEASUREMENT, LC_IDENTIFICATION,LC_ALL") Client programs such as LPR, LPC, etc., will pass these environment variables to any filter programs they start.

poll_time (default: 6000)
    Interval in seconds at which LPD checks for queues with jobs and no server active. See force_poll as well.

pl (default: 66)
    See printcap(5) for details.

pr (default: /bin/pr)
    See printcap(5) for details.

printcap_path
    (default: "/etc/printcap") The location of the printcap database file. If a file or filter does not exist, it is considered a fatal error. All valid entries in these files will be used. See PRINTCAP LOOKUP for details.

perms_path
    (default: /etc/lpd.perms:/usr/etc/lpd.perms: /var/spool/lpd/lpd.perms.%h) The location of the printer permissions database. If a file or filter does not exist, it is skipped. The first file or filter that exists and is readable will be used. See PERMISSIONS LOOKUP for details.

pw (default: 80)
    See printcap(5) for details.

save_on_error
    (default: no) Save a job in the spool queue if it has an error rather than removing it.

save_when_done
    (default: no) Save a job in the spool queue after completion rather than removing it.

send_data_first
    (default: no) Send data files of a job first, followed by the control file.

send_failure_action (default: "")
    The lpd server uses this to determine the action to take when unable to print or process a job. The keyword abort will cause it to terminate operations, leaving the job in the queue, remove will cause it to remove the job, retry will cause it to retry the job, and hold will cause it to hold the job with an error indication. If the value is a filter, then the filter will be invoked and the exit status of the filter used to determine the actions.

send_job_rw_timeout (default: 6000)
    When printing or sending a job to a remote printer, use this as a write to the device or remote host timeout value. If a timeout occurs, then a FAIL status is returned and the send_failure_action value is used to determine what to do on failure.

send_try (default: 3)
    Numbers of times to try to send a job to the printer or remote host. A 0 value means an infinite number of times.

sendmail (default: "/usr/lib/sendmail -oi -t")
    If the argument is empty then all mail_related functionality is disabled. The arguments are the command to run when mail is to be sent. The command used needs to be able to accept the message on stdin, with no arguments. The message will contain the To:, From:, Cc: and Subject: headers.

server_tmp_dir (default: /tmp)
    Temporary dir for the server.

spool_dir_perms (default: 042700)
    Permissions of the spool directories.

spool_file_perms (default: 0600)
    Permissions of the spool files.

syslog_device (default: /dev/console)
    Log to this device if all else fails.

unix_socket_path (default: /var/run/lprng/socket)
    Location of the Unix socket that lpd listens on and LPRng clients attempt to communicate to when host is localhost. Set to off to disable listening and connecting via a Unix socket.

use_date (default: no)
    No information about this parameter available.

use_identifier (default: no)
    Add a job identifier line to the control file, using the 'A' entry in the control file.

use_info_cache (default: yes)
    If this is set to yes, lpd.perms and printcap information lookups will be cached for later use. Only lookups in the main databases will be cached, not lookups in the per_printer databases. You can force the lpd to flush its cache and reread the permissions file by sending it a SIGHUP.

use_queuename (default: no)
    Put an entry into control files identifying the spool queue the job was originally sent to. The entry has the form 'Qspoolname', and its value can be passed to filters. This is useful for setting up a spool queue which formats jobs in different ways, depending on the name of the queue.

use_shorthost (default: no)
    By default, names of lpr job files used the originating host fully qualified domain name. This can exceed 14 characters, the limit of file names on some UNIX systems. If this is set to yes, the non-qualified name will be used, and if the host name is at most 8 characters the file name will be at most 14 characters long.

user (default: daemon)
    The user that lpd and its filters runs as, and the owner of the spool directories and other lpd_writable files. This can be the name of a user or a number. If the user value is 0, then the real UID of the program when started will be used. This allows a non_root user to test the functionality of the LRPng software.

PRINTCAP LOOKUP, DATABASE FILES AND FILTERS

The printcap_path and printer_perms_path variables specify a list of either data base files or filters to use to get printcap or permission entries for a printer. To get information, the filter is started and a single line with the printer name is sent to it. Note that the printer name all is used to request information either about all printers, or a specific printer entry that has a list of all printers. See printcap(5) for more details.

To find the printcap information, LPRng programs will read the database files specified in the printcap_path entry. The lpd server will read any additional files specified in the lpd_printcap_path entry. If any of the files is missing or non-readable a fatal error will result. After having searched the various files, if a filter has been specified the filter will be started and the required printer name will be sent to the filter. The output from the filter will be used as the printcap information.

SECURITY-RELATED PARAMETERS

Environment variables are sanitized by lpd and the other executables, in that the variables IFS, LD_PRELOAD and LD_PROFILE are all deleted from the environment passed to filters and any other sub_processes. For more reliability, script filters should set their own PATH and LD_LIBRARY_PATH variables.

All filters will run as the user and group specified by the group and user variables.

EXAMPLE
# lpd.conf generated from  on Wed Apr  7 07:59:48 PDT 1999

#   The values in this file are the default values.
#   If you modify the file,  set the value to something other than the default
#   For example, '# default force_localhost' means
#     the 'force_localhost' option value is on or 1.
#   Uncomment this and change it to read 'force_localhost@'

# Purpose: always print banner, ignore lpr -h option
#   default ab@
# Purpose: query accounting server when connected
#   default achk@
# Purpose: accounting at end (see also af, la, ar, as)
#   default ae=jobend $H $n $P $k $b $t
# Purpose: name of accounting file (see also la, ar)
#   default af=
af=acct
# Purpose: automatically hold all jobs
#   default ah@
ah
# Purpose: Allow duplicate command line arguments (legacy requirement)
#   default allow_duplicate_args@

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

SEE ALSO
lpc(8), lpd(8), checkpc(8), lpr(1), lpq(1), lprm(1), printcap(5), lpd.perms(5), pr(1), lprng_certs(1), lprng_index_certs(1).

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 mailing list is lprng@lprng.com; subscribe by sending mail to lprng-request@lprng.com with the word subscribe in the body. The software is available from ftp://ftp.lprng.com/pub/LPRng.

AUTHOR
Patrick Powell <papowell@lprng.com>.