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printcap(5)

LPRng
2006-12-09

lprng

lpr/lpd printer spooling system

lpr

BSD lpr/lpd line printer spooling system

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 (‘‘#146;’). 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_zA        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
lockfileD        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_portD        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_envA        str 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
                 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_zD        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_zD        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_tryA        num 3
                 number of times to try sending
                 or printing a job. 0 is infinite.
sendmailD        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_dateA        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 bqfilterD 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_authA str NULL authentication to use use_dateA 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. 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_authD str NULL client to server authentication type, e.g. 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, 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 <>.

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 ; subscribe by visiting https://lists.sourceforge.net/lists/listinfo/lprng-devel or sending mail to with the word subscribe in the body.
The software is available via http://lprng.sourceforge.net
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