LP(1P) - phpMan

LP(1P)                     POSIX Programmer's Manual                    LP(1P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       lp - send files to a printer
SYNOPSIS
       lp [-c][-d dest][-n copies][-msw][-o option]...  [-t title][file...]
DESCRIPTION
       The lp utility shall copy the input files to an output  destination  in
       an  unspecified  manner.  The default output destination should be to a
       hardcopy device, such as a printer or microfilm recorder, that produces
       non-volatile,  human-readable documents. If such a device is not avail-
       able to the application, or if the system provides no such device,  the
       lp utility shall exit with a non-zero exit status.
       The  actual  writing to the output device may occur some time after the
       lp utility successfully exits. During the portion of the  writing  that
       corresponds  to  each  input  file,  the implementation shall guarantee
       exclusive access to the device.
       The lp utility shall associate a unique request ID with each request.
       Normally, a banner page is produced to separate and identify each print
       job.  This page may be suppressed by implementation-defined conditions,
       such as an operator command or one of the -o option values.
OPTIONS
       The lp  utility  shall  conform  to  the  Base  Definitions  volume  of
       IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
       The following options shall be supported:
       -c     Exit  only  after further access to any of the input files is no
              longer required. The application can then safely delete or  mod-
              ify  the files without affecting the output operation. Normally,
              files are not copied, but are linked whenever possible.  If  the
              -c  option  is not given, then the user should be careful not to
              remove any of the files before the request has been  printed  in
              its entirety. It should also be noted that in the absence of the
              -c option, any changes made to the named files after the request
              is made but before it is printed may be reflected in the printed
              output. On some implementations, -c may be on by default.
       -d  dest
              Specify a string that names the destination ( dest). If dest  is
              a  printer,  the  request shall be printed only on that specific
              printer. If dest is a class of printers, the  request  shall  be
              printed  on  the first available printer that is a member of the
              class. Under certain conditions  (printer  unavailability,  file
              space limitation, and so on), requests for specific destinations
              need not be accepted. Destination names vary between systems.
       If -d is not specified, and neither the LPDEST nor PRINTER  environment
       variable is set, an unspecified destination is used. The -d dest option
       shall take precedence over LPDEST,  which in turn shall take precedence
       over PRINTER.  Results are undefined when dest contains a value that is
       not a valid destination name.
       -m     Send mail (see mailx ) after the files  have  been  printed.  By
              default,  no  mail  is  sent upon normal completion of the print
              request.
       -n  copies
              Write copies number of copies of the files, where  copies  is  a
              positive  decimal  integer.  The  methods for producing multiple
              copies and for arranging the multiple copies when multiple  file
              operands  are  used are unspecified, except that each file shall
              be output as an integral whole, not interleaved with portions of
              other files.
       -o  option
              Specify  printer-dependent  or  class-dependent options. Several
              such options may be collected by specifying the -o  option  more
              than once.
       -s     Suppress messages from lp.
       -t  title
              Write title on the banner page of the output.
       -w     Write a message on the user's terminal after the files have been
              printed.  If the user is not logged in, then mail shall be  sent
              instead.

OPERANDS
       The following operand shall be supported:
       file   A pathname of a file to be output. If no file operands are spec-
              ified, or if a file operand is '-', the standard input shall  be
              used. If a file operand is used, but the -c option is not speci-
              fied, the process performing the writing to  the  output  device
              may have user and group permissions that differ from that of the
              process invoking lp.

STDIN
       The standard input shall be used only if no file  operands  are  speci-
       fied, or if a file operand is '-' .  See the INPUT FILES section.
INPUT FILES
       The input files shall be text files.
ENVIRONMENT VARIABLES
       The following environment variables shall affect the execution of lp:
       LANG   Provide  a  default value for the internationalization variables
              that are unset or null. (See  the  Base  Definitions  volume  of
              IEEE Std 1003.1-2001,  Section  8.2,  Internationalization Vari-
              ables for the precedence of internationalization variables  used
              to determine the values of locale categories.)
       LC_ALL If  set  to a non-empty string value, override the values of all
              the other internationalization variables.
       LC_CTYPE
              Determine the locale for  the  interpretation  of  sequences  of
              bytes  of  text  data as characters (for example, single-byte as
              opposed to multi-byte characters in arguments and input files).
       LC_MESSAGES
              Determine the locale that should be used to  affect  the  format
              and  contents  of  diagnostic messages written to standard error
              and informative messages written to standard output.
       LC_TIME
              Determine the format and contents of date and time strings  dis-
              played in the lp banner page, if any.
       LPDEST Determine the destination. If the LPDEST environment variable is
              not set, the PRINTER environment variable shall be used. The  -d
              dest option takes precedence over LPDEST . Results are undefined
              when -d is not specified and LPDEST contains a value that is not
              a valid destination name.
       NLSPATH
              Determine the location of message catalogs for the processing of
              LC_MESSAGES .
       PRINTER
              Determine the output device or destination. If  the  LPDEST  and
              PRINTER environment variables are not set, an unspecified output
              device is used. The -d dest option and  the  LPDEST  environment
              variable  shall take precedence over PRINTER.  Results are unde-
              fined when -d is not specified, LPDEST  is  unset,  and  PRINTER
              contains a value that is not a valid device or destination name.
       TZ     Determine  the  timezone used to calculate date and time strings
              displayed in the lp banner page, if any. If TZ is unset or null,
              an unspecified default timezone shall be used.

ASYNCHRONOUS EVENTS
       Default.
STDOUT
       The  lp utility shall write a request ID to the standard output, unless
       -s is specified. The format of the message is unspecified. The  request
       ID  can  be used on systems supporting the historical cancel and lpstat
       utilities.
STDERR
       The standard error shall be used only for diagnostic messages.
OUTPUT FILES
       None.
EXTENDED DESCRIPTION
       None.
EXIT STATUS
       The following exit values shall be returned:
        0     All input files were processed successfully.
       >0     No output device was available, or an error occurred.

CONSEQUENCES OF ERRORS
       Default.
       The following sections are informative.
APPLICATION USAGE
       The pr and fold utilities can be used to achieve reasonable  formatting
       for the implementation's default page size.
       A conforming application can use one of the file operands only with the
       -c option or if the file is publicly  readable  and  guaranteed  to  be
       available at the time of printing. This is because IEEE Std 1003.1-2001
       gives the implementation the freedom to queue up the request for print-
       ing at some later time by a different process that might not be able to
       access the file.
EXAMPLES
        1. To print file file:

           lp -c file
        2. To print multiple files with headers:

           pr file1 file2 | lp
RATIONALE
       The lp utility was designed to be a basic version of a utility that  is
       already  available  in  many  historical  implementations. The standard
       developers considered that it should be implementable simply as:

              cat "$@" > /dev/lp
       after appropriate processing of options, if that is how the implementa-
       tion  chose  to do it and if exclusive access could be granted (so that
       two users did not write to the device simultaneously).  Although in the
       future  the  standard developers may add other options to this utility,
       it should always be able to execute with no  options  or  operands  and
       send the standard input to an unspecified output device.
       This volume of IEEE Std 1003.1-2001 makes no representations concerning
       the format of the printed output, except that it must  be  "human-read-
       able"  and  "non-volatile".  Thus, writing by default to a disk or tape
       drive or a display terminal would not qualify. (Such  destinations  are
       not prohibited when -d dest, LPDEST,  or PRINTER are used, however.)
       This  volume  of IEEE Std 1003.1-2001 is worded such that a "print job"
       consisting of multiple input files, possibly  in  multiple  copies,  is
       guaranteed  to  print  so  that  any  one  file  is not intermixed with
       another, but there is no statement that all the files or copies have to
       print out together.
       The -c option may imply a spooling operation, but this is not required.
       The utility can be implemented to wait until the printer is  ready  and
       then wait until it is finished. Because of that, there is no attempt to
       define a queuing mechanism (priorities, classes of output, and so on).
       On some historical systems, the request ID reported on the  STDOUT  can
       be used to later cancel or find the status of a request using utilities
       not defined in this volume of IEEE Std 1003.1-2001.
       Although the historical System V lp and BSD lpr utilities have provided
       similar  functionality,  they  used different names for the environment
       variable specifying the destination printer.  Since  the  name  of  the
       utility  here is lp, LPDEST (used by the System V lp utility) was given
       precedence over PRINTER (used by the BSD lpr utility).  Since  environ-
       ments  of  users  frequently contain one or the other environment vari-
       able, the lp utility is required to recognize both.  If  this  was  not
       done,  many applications would send output to unexpected output devices
       when users moved from system to system.
       Some have commented that lp has far too little functionality to make it
       worthwhile.  Requests  have  proposed additional options or operands or
       both that added functionality. The requests included:
        * Wording requiring the output to be "hardcopy"
        * A requirement for multiple printers
        * Options for supporting various page-description languages
       Given that a compliant system is not required to even have  a  printer,
       placing  further  restrictions  upon the behavior of the printer is not
       useful. Since hardcopy format is so application-dependent, it is diffi-
       cult, if not impossible, to select a reasonable subset of functionality
       that should be required on all compliant systems.
       The term unspecified is used in this section in lieu of implementation-
       defined as most known implementations would not be able to make defini-
       tive statements in their conformance documents; the existence and usage
       of  printers  is very dependent on how the system administrator config-
       ures each individual system.
       Since the default destination, device  type,  queuing  mechanisms,  and
       acceptable  forms  of  input  are all unspecified, usage guidelines for
       what a conforming application can do are as follows:
        * Use the command in a pipeline, or with -c, so that there are no per-
          mission problems and the files can be safely deleted or modified.
        * Limit  output to text files of reasonable line lengths and printable
          characters and include no  device-specific  formatting  information,
          such  as a page description language. The meaning of "reasonable" in
          this context can only be  answered  as  a  quality-of-implementation
          issue,  but  it should be apparent from historical usage patterns in
          the industry and the locale. The pr and fold utilities can  be  used
          to  achieve  reasonable  formatting for the default page size of the
          implementation.
       Alternatively, the application can arrange its installation in  such  a
       way  that  it  requires the system administrator or operator to provide
       the appropriate information on lp options and environment variable val-
       ues.
       At    a    minimum,   having   this   utility   in   this   volume   of
       IEEE Std 1003.1-2001 tells the industry  that  conforming  applications
       require  a  means  to print output and provides at least a command name
       and LPDEST routing mechanism that can be used for  discussions  between
       vendors,  application  writers,  and users.  The use of "should" in the
       DESCRIPTION of lp clearly shows the intent of the standard  developers,
       even  if  they  cannot  mandate that all systems (such as laptops) have
       printers.
       This volume of IEEE Std 1003.1-2001 does not specify what the ownership
       of  the  process performing the writing to the output device may be. If
       -c is not used, it is unspecified whether the  process  performing  the
       writing  to  the output device has permission to read file if there are
       any restrictions in place on who  may  read  file  until  after  it  is
       printed.   Also, if -c is not used, the results of deleting file before
       it is printed are unspecified.
FUTURE DIRECTIONS
       None.
SEE ALSO
       mailx
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                               LP(1P)