1LP(1P) POSIX Programmer's Manual LP(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 lp - send files to a printer
13
15 lp [-c][-d dest][-n copies][-msw][-o option]... [-t title][file...]
16
18 The lp utility shall copy the input files to an output destination in
19 an unspecified manner. The default output destination should be to a
20 hardcopy device, such as a printer or microfilm recorder, that produces
21 non-volatile, human-readable documents. If such a device is not avail‐
22 able to the application, or if the system provides no such device, the
23 lp utility shall exit with a non-zero exit status.
24 The actual writing to the output device may occur some time after the
26 lp utility successfully exits. During the portion of the writing that
27 corresponds to each input file, the implementation shall guarantee
28 exclusive access to the device.
29 The lp utility shall associate a unique request ID with each request.
31 Normally, a banner page is produced to separate and identify each print
33 job. This page may be suppressed by implementation-defined conditions,
34 such as an operator command or one of the -o option values.
35
37 The lp utility shall conform to the Base Definitions volume of
38 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
39 The following options shall be supported:
41 -c Exit only after further access to any of the input files is no
43 longer required. The application can then safely delete or mod‐
44 ify the files without affecting the output operation. Normally,
45 files are not copied, but are linked whenever possible. If the
46 -c option is not given, then the user should be careful not to
47 remove any of the files before the request has been printed in
48 its entirety. It should also be noted that in the absence of the
49 -c option, any changes made to the named files after the request
50 is made but before it is printed may be reflected in the printed
51 output. On some implementations, -c may be on by default.
52 -d dest
54 Specify a string that names the destination ( dest). If dest is
55 a printer, the request shall be printed only on that specific
56 printer. If dest is a class of printers, the request shall be
57 printed on the first available printer that is a member of the
58 class. Under certain conditions (printer unavailability, file
59 space limitation, and so on), requests for specific destinations
60 need not be accepted. Destination names vary between systems.
61 If -d is not specified, and neither the LPDEST nor PRINTER environment
63 variable is set, an unspecified destination is used. The -d dest option
64 shall take precedence over LPDEST, which in turn shall take precedence
65 over PRINTER. Results are undefined when dest contains a value that is
66 not a valid destination name.
67 -m Send mail (see mailx ) after the files have been printed. By
69 default, no mail is sent upon normal completion of the print
70 request.
71 -n copies
73 Write copies number of copies of the files, where copies is a
74 positive decimal integer. The methods for producing multiple
75 copies and for arranging the multiple copies when multiple file
76 operands are used are unspecified, except that each file shall
77 be output as an integral whole, not interleaved with portions of
78 other files.
79 -o option
81 Specify printer-dependent or class-dependent options. Several
82 such options may be collected by specifying the -o option more
83 than once.
84 -s Suppress messages from lp.
86 -t title
88 Write title on the banner page of the output.
89 -w Write a message on the user's terminal after the files have been
91 printed. If the user is not logged in, then mail shall be sent
92 instead.
93
96 The following operand shall be supported:
97 file A pathname of a file to be output. If no file operands are spec‐
99 ified, or if a file operand is '-', the standard input shall be
100 used. If a file operand is used, but the -c option is not speci‐
101 fied, the process performing the writing to the output device
102 may have user and group permissions that differ from that of the
103 process invoking lp.
104
107 The standard input shall be used only if no file operands are speci‐
108 fied, or if a file operand is '-' . See the INPUT FILES section.
109
111 The input files shall be text files.
112
114 The following environment variables shall affect the execution of lp:
115 LANG Provide a default value for the internationalization variables
117 that are unset or null. (See the Base Definitions volume of
118 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
119 ables for the precedence of internationalization variables used
120 to determine the values of locale categories.)
121 LC_ALL If set to a non-empty string value, override the values of all
123 the other internationalization variables.
124 LC_CTYPE
126 Determine the locale for the interpretation of sequences of
127 bytes of text data as characters (for example, single-byte as
128 opposed to multi-byte characters in arguments and input files).
129 LC_MESSAGES
131 Determine the locale that should be used to affect the format
132 and contents of diagnostic messages written to standard error
133 and informative messages written to standard output.
134 LC_TIME
136 Determine the format and contents of date and time strings dis‐
137 played in the lp banner page, if any.
138 LPDEST Determine the destination. If the LPDEST environment variable is
140 not set, the PRINTER environment variable shall be used. The -d
141 dest option takes precedence over LPDEST . Results are undefined
142 when -d is not specified and LPDEST contains a value that is not
143 a valid destination name.
144 NLSPATH
146 Determine the location of message catalogs for the processing of
147 LC_MESSAGES .
148 PRINTER
150 Determine the output device or destination. If the LPDEST and
151 PRINTER environment variables are not set, an unspecified output
152 device is used. The -d dest option and the LPDEST environment
153 variable shall take precedence over PRINTER. Results are unde‐
154 fined when -d is not specified, LPDEST is unset, and PRINTER
155 contains a value that is not a valid device or destination name.
156 TZ Determine the timezone used to calculate date and time strings
158 displayed in the lp banner page, if any. If TZ is unset or null,
159 an unspecified default timezone shall be used.
160
163 Default.
164
166 The lp utility shall write a request ID to the standard output, unless
167 -s is specified. The format of the message is unspecified. The request
168 ID can be used on systems supporting the historical cancel and lpstat
169 utilities.
170
172 The standard error shall be used only for diagnostic messages.
173
175 None.
176
178 None.
179
181 The following exit values shall be returned:
182 0 All input files were processed successfully.
184 >0 No output device was available, or an error occurred.
186
189 Default.
190 The following sections are informative.
192
194 The pr and fold utilities can be used to achieve reasonable formatting
195 for the implementation's default page size.
196 A conforming application can use one of the file operands only with the
198 -c option or if the file is publicly readable and guaranteed to be
199 available at the time of printing. This is because IEEE Std 1003.1-2001
200 gives the implementation the freedom to queue up the request for print‐
201 ing at some later time by a different process that might not be able to
202 access the file.
203
205 1. To print file file:
206 lp -c file
209 2. To print multiple files with headers:
211 pr file1 file2 | lp
214
216 The lp utility was designed to be a basic version of a utility that is
217 already available in many historical implementations. The standard
218 developers considered that it should be implementable simply as:
219 cat "$@" > /dev/lp
222 after appropriate processing of options, if that is how the implementa‐
224 tion chose to do it and if exclusive access could be granted (so that
225 two users did not write to the device simultaneously). Although in the
226 future the standard developers may add other options to this utility,
227 it should always be able to execute with no options or operands and
228 send the standard input to an unspecified output device.
229 This volume of IEEE Std 1003.1-2001 makes no representations concerning
231 the format of the printed output, except that it must be "human-read‐
232 able" and "non-volatile". Thus, writing by default to a disk or tape
233 drive or a display terminal would not qualify. (Such destinations are
234 not prohibited when -d dest, LPDEST, or PRINTER are used, however.)
235 This volume of IEEE Std 1003.1-2001 is worded such that a "print job"
237 consisting of multiple input files, possibly in multiple copies, is
238 guaranteed to print so that any one file is not intermixed with
239 another, but there is no statement that all the files or copies have to
240 print out together.
241 The -c option may imply a spooling operation, but this is not required.
243 The utility can be implemented to wait until the printer is ready and
244 then wait until it is finished. Because of that, there is no attempt to
245 define a queuing mechanism (priorities, classes of output, and so on).
246 On some historical systems, the request ID reported on the STDOUT can
248 be used to later cancel or find the status of a request using utilities
249 not defined in this volume of IEEE Std 1003.1-2001.
250 Although the historical System V lp and BSD lpr utilities have provided
252 similar functionality, they used different names for the environment
253 variable specifying the destination printer. Since the name of the
254 utility here is lp, LPDEST (used by the System V lp utility) was given
255 precedence over PRINTER (used by the BSD lpr utility). Since environ‐
256 ments of users frequently contain one or the other environment vari‐
257 able, the lp utility is required to recognize both. If this was not
258 done, many applications would send output to unexpected output devices
259 when users moved from system to system.
260 Some have commented that lp has far too little functionality to make it
262 worthwhile. Requests have proposed additional options or operands or
263 both that added functionality. The requests included:
264 * Wording requiring the output to be "hardcopy"
266 * A requirement for multiple printers
268 * Options for supporting various page-description languages
270 Given that a compliant system is not required to even have a printer,
272 placing further restrictions upon the behavior of the printer is not
273 useful. Since hardcopy format is so application-dependent, it is diffi‐
274 cult, if not impossible, to select a reasonable subset of functionality
275 that should be required on all compliant systems.
276 The term unspecified is used in this section in lieu of implementation-
278 defined as most known implementations would not be able to make defini‐
279 tive statements in their conformance documents; the existence and usage
280 of printers is very dependent on how the system administrator config‐
281 ures each individual system.
282 Since the default destination, device type, queuing mechanisms, and
284 acceptable forms of input are all unspecified, usage guidelines for
285 what a conforming application can do are as follows:
286 * Use the command in a pipeline, or with -c, so that there are no per‐
288 mission problems and the files can be safely deleted or modified.
289 * Limit output to text files of reasonable line lengths and printable
291 characters and include no device-specific formatting information,
292 such as a page description language. The meaning of "reasonable" in
293 this context can only be answered as a quality-of-implementation
294 issue, but it should be apparent from historical usage patterns in
295 the industry and the locale. The pr and fold utilities can be used
296 to achieve reasonable formatting for the default page size of the
297 implementation.
298 Alternatively, the application can arrange its installation in such a
300 way that it requires the system administrator or operator to provide
301 the appropriate information on lp options and environment variable val‐
302 ues.
303 At a minimum, having this utility in this volume of
305 IEEE Std 1003.1-2001 tells the industry that conforming applications
306 require a means to print output and provides at least a command name
307 and LPDEST routing mechanism that can be used for discussions between
308 vendors, application writers, and users. The use of "should" in the
309 DESCRIPTION of lp clearly shows the intent of the standard developers,
310 even if they cannot mandate that all systems (such as laptops) have
311 printers.
312 This volume of IEEE Std 1003.1-2001 does not specify what the ownership
314 of the process performing the writing to the output device may be. If
315 -c is not used, it is unspecified whether the process performing the
316 writing to the output device has permission to read file if there are
317 any restrictions in place on who may read file until after it is
318 printed. Also, if -c is not used, the results of deleting file before
319 it is printed are unspecified.
320
322 None.
323
325 mailx
326
328 Portions of this text are reprinted and reproduced in electronic form
329 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
330 -- Portable Operating System Interface (POSIX), The Open Group Base
331 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
332 Electrical and Electronics Engineers, Inc and The Open Group. In the
333 event of any discrepancy between this version and the original IEEE and
334 The Open Group Standard, the original IEEE and The Open Group Standard
335 is the referee document. The original Standard can be obtained online
336 at http://www.opengroup.org/unix/online.html .
337IEEE/The Open Group 2003 LP(1P)