Movatterモバイル変換

Network Printing Working Group                 L. McLaughlin III, EditorRequest for Comments:  1179                         The Wollongong Group                                                             August 1990Line Printer Daemon ProtocolStatus of this Memo   This RFC describes an existing print server protocol widely used on   the Internet for communicating between line printer daemons (both   clients and servers).  This memo is for informational purposes only,   and does not specify an Internet standard.  Please refer to the   current edition of the "IAB Official Protocol Standards" for the   standardization state and status of this protocol.  Distribution of   this memo is unlimited.1. Introduction   The Berkeley versions of the Unix(tm) operating system provide line   printer spooling with a collection of programs: lpr (assign to   queue), lpq (display the queue), lprm (remove from queue), and lpc   (control the queue).  These programs interact with an autonomous   process called the line printer daemon.  This RFC describes the   protocols with which a line printer daemon client may control   printing.   This memo is based almost entirely on the work of Robert Knight at   Princeton University.  I gratefully acknowledge his efforts in   deciphering the UNIX lpr protocol and producing earlier versions of   this document.2. Model of Printing Environment   A group of hosts request services from a line printer daemon process   running on a host.  The services provided by the process are related   to printing jobs.  A printing job produces output from one file.   Each job will have a unique job number which is between 0 and 999,   inclusive.  The jobs are requested by users which have names.  These   user names may not start with a digit.3. Specification of the Protocol   The specification includes file formats for the control and data   files as well as messages used by the protocol.McLaughlin                                                      [Page 1]

RFC 1179                          LPR                        August 19903.1 Message formats   LPR is a a TCP-based protocol.  The port on which a line printer   daemon listens is 515.  The source port must be in the range 721 to   731, inclusive.  A line printer daemon responds to commands send to   its port.  All commands begin with a single octet code, which is a   binary number which represents the requested function.  The code is   immediately followed by the ASCII name of the printer queue name on   which the function is to be performed.  If there are other operands   to the command, they are separated from the printer queue name with   white space (ASCII space, horizontal tab, vertical tab, and form   feed).  The end of the command is indicated with an ASCII line feed   character.4. Diagram Conventions   The diagrams in the rest of this RFC use these conventions.  These   diagrams show the format of an octet stream sent to the server.  The   outermost box represents this stream.  Each box within the outermost   one shows one portion of the stream.  If the contents of the box is   two decimal digits, this indicates that the binary 8 bit value is to   be used.  If the contents is two uppercase letters, this indicates   that the corresponding ASCII control character is to be used.  An   exception to this is that the character SP can be interpreted as   white space.  (See the preceding section for a definition.)  If the   contents is a single letter, the ASCII code for this letter must be   sent.  Otherwise, the contents are intended to be mnemonic of the   contents of the field which is a sequence of octets.5. Daemon commands   The verbs in the command names should be interpreted as statements   made to the daemon.  Thus, the command "Print any waiting jobs" is an   imperative to the line printer daemon to which it is sent.  A new   connection must be made for each command to be given to the daemon.5.1 01 - Print any waiting jobs      +----+-------+----+      | 01 | Queue | LF |      +----+-------+----+      Command code - 1      Operand - Printer queue name   This command starts the printing process if it not already running.McLaughlin                                                      [Page 2]

RFC 1179                          LPR                        August 19905.2 02 - Receive a printer job      +----+-------+----+      | 02 | Queue | LF |      +----+-------+----+      Command code - 2      Operand - Printer queue name   Receiving a job is controlled by a second level of commands.  The   daemon is given commands by sending them over the same connection.   The commands are described in the next section (6).   After this command is sent, the client must read an acknowledgement   octet from the daemon.  A positive acknowledgement is an octet of   zero bits.  A negative acknowledgement is an octet of any other   pattern.5.3 03 - Send queue state (short)      +----+-------+----+------+----+      | 03 | Queue | SP | List | LF |      +----+-------+----+------+----+      Command code - 3      Operand 1 - Printer queue name      Other operands - User names or job numbers   If the user names or job numbers or both are supplied then only those   jobs for those users or with those numbers will be sent.   The response is an ASCII stream which describes the printer queue.   The stream continues until the connection closes.  Ends of lines are   indicated with ASCII LF control characters.  The lines may also   contain ASCII HT control characters.5.4 04 - Send queue state (long)      +----+-------+----+------+----+      | 04 | Queue | SP | List | LF |      +----+-------+----+------+----+      Command code - 4      Operand 1 - Printer queue name      Other operands - User names or job numbers   If the user names or job numbers or both are supplied then only those   jobs for those users or with those numbers will be sent.   The response is an ASCII stream which describes the printer queue.   The stream continues until the connection closes.  Ends of lines areMcLaughlin                                                      [Page 3]

RFC 1179                          LPR                        August 1990   indicated with ASCII LF control characters.  The lines may also   contain ASCII HT control characters.5.5 05 - Remove jobs      +----+-------+----+-------+----+------+----+      | 05 | Queue | SP | Agent | SP | List | LF |      +----+-------+----+-------+----+------+----+      Command code - 5      Operand 1 - Printer queue name      Operand 2 - User name making request (the agent)      Other operands - User names or job numbers   This command deletes the print jobs from the specified queue which   are listed as the other operands.  If only the agent is given, the   command is to delete the currently active job.  Unless the agent is   "root", it is not possible to delete a job which is not owned by the   user.  This is also the case for specifying user names instead of   numbers.  That is, agent "root" can delete jobs by user name but no   other agents can.6. Receive job subcommands   These commands  are processed when  the line printer  daemon  has   been given the  receive job command.  The  daemon will continue  to   process commands until the connection is closed.   After a subcommand is sent, the client must wait for an   acknowledgement from the daemon.  A positive acknowledgement is an   octet of zero bits.  A negative acknowledgement is an octet of any   other pattern.   LPR clients SHOULD be able to sent the receive data file and receive   control file subcommands in either order.  LPR servers MUST be able   to receive the control file subcommand first and SHOULD be able to   receive the data file subcommand first.6.1 01 - Abort job      Command code - 1      +----+----+      | 01 | LF |      +----+----+   No operands should be supplied.  This subcommand will remove any   files which have been created during this "Receive job" command.McLaughlin                                                      [Page 4]

RFC 1179                          LPR                        August 19906.2 02 - Receive control file      +----+-------+----+------+----+      | 02 | Count | SP | Name | LF |      +----+-------+----+------+----+      Command code - 2      Operand 1 - Number of bytes in control file      Operand 2 - Name of control file   The control file must be an ASCII stream with the ends of lines   indicated by ASCII LF.  The total number of bytes in the stream is   sent as the first operand.  The name of the control file is sent as   the second.  It should start with ASCII "cfA", followed by a three   digit job number, followed by the host name which has constructed the   control file.  Acknowledgement processing must occur as usual after   the command is sent.   The next "Operand 1" octets over the same TCP connection are the   intended contents of the control file.  Once all of the contents have   been delivered, an octet of zero bits is sent as an indication that   the file being sent is complete.  A second level of acknowledgement   processing must occur at this point.6.3 03 - Receive data file      +----+-------+----+------+----+      | 03 | Count | SP | Name | LF |      +----+-------+----+------+----+      Command code - 3      Operand 1 - Number of bytes in data file      Operand 2 - Name of data file   The data file may contain any 8 bit values at all.  The total number   of bytes in the stream may be sent as the first operand, otherwise   the field should be cleared to 0.  The name of the data file should   start with ASCII "dfA".  This should be followed by a three digit job   number.  The job number should be followed by the host name which has   constructed the data file.  Interpretation of the contents of the   data file is determined by the contents of the corresponding control   file.  If a data file length has been specified, the next "Operand 1"   octets over the same TCP connection are the intended contents of the   data file.  In this case, once all of the contents have been   delivered, an octet of zero bits is sent as an indication that the   file being sent is complete.  A second level of acknowledgement   processing must occur at this point.McLaughlin                                                      [Page 5]

RFC 1179                          LPR                        August 19907. Control file lines   This section  discusses the format of  the lines in the  control file   which is sent to the line printer daemon.   Each line of the control file consists of a single, printable ASCII   character which represents a function to be performed when the file   is printed.  Interpretation of these command characters are case-   sensitive.  The rest of the line after the command character is the   command's operand.  No leading white space is permitted after the   command character.  The line ends with an ASCII new line.   Those commands which have a lower case letter as a command code are   used to specify an actual printing request.  The commands which use   upper case are used to describe parametric values or background   conditions.   Some commands must be included in every control file.  These are 'H'   (responsible host) and 'P' (responsible user).  Additionally, there   must be at least one lower case command to produce any output.7.1 C - Class for banner page      +---+-------+----+      | C | Class | LF |      +---+-------+----+      Command code - 'C'      Operand - Name of class for banner pages   This command sets the class name to be printed on the banner page.   The name must be 31 or fewer octets.  The name can be omitted.  If it   is, the name of the host on which the file is printed will be used.   The class is conventionally used to display the host from which the   printing job originated.  It will be ignored unless the print banner   command ('L') is also used.7.2 H - Host name      +---+------+----+      | H | Host | LF |      +---+------+----+      Command code - 'H'      Operand - Name of host   This command specifies the name of the host which is to be treated as   the source of the print job.  The command must be included in the   control file.  The name of the host must be 31 or fewer octets.McLaughlin                                                      [Page 6]

RFC 1179                          LPR                        August 19907.3 I - Indent Printing      +---+-------+----+      | I | count | LF |      +---+-------+----+      Command code - 'I'      Operand - Indenting count   This command specifies that, for files which are printed with the   'f', of columns given.  (It is ignored for other output generating   commands.)  The identing count operand must be all decimal digits.7.4 J - Job name for banner page      +---+----------+----+      | J | Job name | LF |      +---+----------+----+      Command code - 'J'      Operand - Job name   This command sets the job name to be printed on the banner page.  The   name of the job must be 99 or fewer octets.  It can be omitted.  The   job name is conventionally used to display the name of the file or   files which were "printed".  It will be ignored unless the print   banner command ('L') is also used.7.5 L - Print banner page      +---+------+----+      | L | User | LF |      +---+------+----+      Command code - 'L'      Operand - Name of user for burst pages   This command causes the banner page to be printed.  The user name can   be omitted.  The class name for banner page and job name for banner   page commands must precede this command in the control file to be   effective.7.6 M - Mail When Printed      +---+------+----+      | M | user | LF |      +---+------+----+      Command code - 'M'      Operand - User name   This entry causes mail to be sent to the user given as the operand atMcLaughlin                                                      [Page 7]

RFC 1179                          LPR                        August 1990   the host specified by the 'H' entry when the printing operation ends   (successfully or unsuccessfully).7.7 N - Name of source file      +---+------+----+      | N | Name | LF |      +---+------+----+      Command code - 'N'      Operand - File name   This command specifies the name of the file from which the data file   was constructed.  It is returned on a query and used in printing with   the 'p' command when no title has been given.  It must be 131 or   fewer octets.7.8 P - User identification      +---+------+----+      | P | Name | LF |      +---+------+----+      Command code - 'P'      Operand - User id   This command specifies the user identification of the entity   requesting the printing job.  This command must be included in the   control file.  The user identification must be 31 or fewer octets.7.9 S - Symbolic link data      +---+--------+----+-------+----+      | S | device | SP | inode | LF |      +---+--------+----+-------+----+      Command code - 'S'      Operand 1 - Device number      Operand 2 - Inode number   This command is used to record symbolic link data on a Unix system so   that changing a file's directory entry after a file is printed will   not print the new file.  It is ignored if the data file is not   symbolically linked.McLaughlin                                                      [Page 8]

RFC 1179                          LPR                        August 19907.10 T - Title for pr      +---+-------+----+      | T | title | LF |      +---+-------+----+      Command code - 'T'      Operand - Title text   This command provides a title for a file which is to be printed with   either the 'p' command.  (It is ignored by all of the other printing   commands.)  The title must be 79 or fewer octets.7.11 U - Unlink data file      +---+------+----+      | U | file | LF |      +---+------+----+      Command code - 'U'      Operand - File to unlink   This command indicates that the specified file is no longer needed.   This should only be used for data files.7.12 W - Width of output      +---+-------+----+      | W | width | LF |      +---+-------+----+      Command code - 'W'      Operand - Width count   This command limits the output to the specified number of columns for   the 'f', 'l', and 'p' commands.  (It is ignored for other output   generating commands.)  The width count operand must be all decimal   digits.  It may be silently reduced to some lower value.  The default   value for the width is 132.7.13 1 - troff R font      +---+------+----+      | 1 | file | LF |      +---+------+----+      Command code - '1'      Operand - File name   This command specifies the file name for the troff R font.  [1] This   is the font which is printed using Times Roman by default.McLaughlin                                                      [Page 9]

RFC 1179                          LPR                        August 19907.14 2 - troff I font      +---+------+----+      | 2 | file | LF |      +---+------+----+      Command code - '2'      Operand - File name   This command specifies the file name for the troff I font.  [1] This   is the font which is printed using Times Italic by default.7.15 3 - troff B font      +---+------+----+      | 3 | file | LF |      +---+------+----+      Command code - '3'      Operand - File name   This command specifies the file name for the troff B font.  [1] This   is the font which is printed using Times Bold by default.7.16 4 - troff S font      +---+------+----+      | 4 | file | LF |      +---+------+----+      Command code - '4'      Operand - File name   This command specifies the file name for the troff S font.  [1] This   is the font which is printed using Special Mathematical Font by   default.7.17 c - Plot CIF file      +---+------+----+      | c | file | LF |      +---+------+----+      Command code - 'c'      Operand - File to plot   This command causes the data file to be plotted, treating the data as   CIF (CalTech Intermediate Form) graphics language. [2]McLaughlin                                                     [Page 10]

RFC 1179                          LPR                        August 19907.18 d - Print DVI file      +---+------+----+      | d | file | LF |      +---+------+----+      Command code - 'd'      Operand - File to print   This command causes the data file to be printed, treating the data as   DVI (TeX output). [3]7.19 f - Print formatted file      +---+------+----+      | f | file | LF |      +---+------+----+      Command code - 'f'      Operand - File to print   This command cause the data file to be printed as a plain text file,   providing page breaks as necessary.  Any ASCII control characters   which are not in the following list are discarded: HT, CR, FF, LF,   and BS.7.20 g - Plot file      +---+------+----+      | g | file | LF |      +---+------+----+      Command code - 'g'      Operand - File to plot   This command causes the data file to be plotted, treating the data as   output from the Berkeley Unix plot library. [1]7.21 k - Reserved for use by Kerberized LPR clients and servers.7.22 l - Print file leaving control characters      +---+------+----+      | l | file | LF |      +---+------+----+      Command code - 'l' (lower case L)      Operand - File to print   This command causes the specified data file to printed without   filtering the control characters (as is done with the 'f' command).McLaughlin                                                     [Page 11]

RFC 1179                          LPR                        August 19907.23 n - Print ditroff output file      +---+------+----+      | n | file | LF |      +---+------+----+      Command code - 'n'      Operand - File to print   This command prints the data file to be printed, treating the data as   ditroff output. [4]7.24 o - Print Postscript output file      +---+------+----+      | o | file | LF |      +---+------+----+      Command code - 'o'      Operand - File to print   This command prints the data file to be printed, treating the data as   standard Postscript input.7.25 p - Print file with 'pr' format      +---+------+----+      | p | file | LF |      +---+------+----+      Command code - 'p'      Operand - File to print   This command causes the data file to be printed with a heading, page   numbers, and pagination.  The heading should include the date and   time that printing was started, the title, and a page number   identifier followed by the page number.  The title is the name of   file as specified by the 'N' command, unless the 'T' command (title)   has been given.  After a page of text has been printed, a new page is   started with a new page number.  (There is no way to specify the   length of the page.)7.26 r - File to print with FORTRAN carriage control      +---+------+----+      | r | file | LF |      +---+------+----+      Command code - 'r'      Operand - File to print   This command causes the data file to be printed, interpreting theMcLaughlin                                                     [Page 12]

RFC 1179                          LPR                        August 1990   first column of each line as FORTRAN carriage control.  The FORTRAN   standard limits this to blank, "1", "0", and "+" carriage controls.   Most FORTRAN programmers also expect "-" (triple space) to work as   well.7.27 t - Print troff output file      +---+------+----+      | t | file | LF |      +---+------+----+      Command code - 't'      Operand - File to print   This command prints the data file as Graphic Systems C/A/T   phototypesetter input.  [5] This is the standard output of the Unix   "troff" command.7.28 v - Print raster file      +---+------+----+      | v | file | LF |      +---+------+----+      Command code - 'v'      Operand - File to print   This command prints a Sun raster format file. [6]7.29 z - Reserved for future use with the Palladium print system.REFERENCES and BIBLIOGRAPHY   [1] Computer Science Research Group, "UNIX Programmer's Reference       Manual", USENIX, 1986.   [2] Hon and Sequin, "A Guide to LSI Implementation", XEROX PARC,       1980.   [3] Knuth, D., "TeX The Program".   [4] Kernighan, B., "A Typesetter-independent TROFF".   [5] "Model C/A/T Phototypesetter", Graphic Systems, Inc. Hudson, N.H.   [6] Sun Microsystems, "Pixrect Reference Manual", Sun Microsystems,       Mountain View, CA, 1988.McLaughlin                                                     [Page 13]

RFC 1179                          LPR                        August 1990Security Considerations   Security issues are not discussed in this memo.Author's Address   Leo J. McLaughlin III   The Wollongong Group   1129 San Antonio Road   Palo Alto, CA 94303   Phone: 415-962-7100   EMail: ljm@twg.comMcLaughlin                                                     [Page 14]