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1 .\" $Id: mandoc.1,v 1.189 2017/05/30 19:30:38 schwarze Exp $
2 .\"
3 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4 .\" Copyright (c) 2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
5 .\"
6 .\" Permission to use, copy, modify, and distribute this software for any
7 .\" purpose with or without fee is hereby granted, provided that the above
8 .\" copyright notice and this permission notice appear in all copies.
9 .\"
10 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 .\"
18 .Dd $Mdocdate: May 30 2017 $
19 .Dt MANDOC 1
20 .Os
21 .Sh NAME
22 .Nm mandoc
23 .Nd format manual pages
24 .Sh SYNOPSIS
25 .Nm mandoc
26 .Op Fl ac
27 .Op Fl I Cm os Ns = Ns Ar name
28 .Op Fl K Ar encoding
29 .Op Fl mdoc | man
30 .Op Fl O Ar options
31 .Op Fl T Ar output
32 .Op Fl W Ar level
33 .Op Ar
34 .Sh DESCRIPTION
35 The
36 .Nm
37 utility formats
38 .Ux
39 manual pages for display.
40 .Pp
41 By default,
42 .Nm
43 reads
44 .Xr mdoc 7
45 or
46 .Xr man 7
47 text from stdin and produces
48 .Fl T Cm locale
49 output.
50 .Pp
51 The options are as follows:
52 .Bl -tag -width Ds
53 .It Fl a
54 If the standard output is a terminal device and
55 .Fl c
56 is not specified, use
57 .Xr more 1
58 to paginate the output, just like
59 .Xr man 1
60 would.
61 .It Fl c
62 Copy the formatted manual pages to the standard output without using
63 .Xr more 1
64 to paginate them.
65 This is the default.
66 It can be specified to override
67 .Fl a .
68 .It Fl I Cm os Ns = Ns Ar name
69 Override the default operating system
70 .Ar name
71 for the
72 .Xr mdoc 7
73 .Ic \&Os
74 and for the
75 .Xr man 7
76 .Ic \&TH
77 macro.
78 .It Fl K Ar encoding
79 Specify the input encoding.
80 The supported
81 .Ar encoding
82 arguments are
83 .Cm us-ascii ,
84 .Cm iso-8859-1 ,
85 and
86 .Cm utf-8 .
87 If not specified, autodetection uses the first match in the following
88 list:
89 .Bl -enum
90 .It
91 If the first three bytes of the input file are the UTF-8 byte order
92 mark (BOM, 0xefbbbf), input is interpreted as
93 .Cm utf-8 .
94 .It
95 If the first or second line of the input file matches the
96 .Sy emacs
97 mode line format
98 .Pp
99 .D1 .\e" -*- Oo ...; Oc coding: Ar encoding ; No -*-
100 .Pp
101 then input is interpreted according to
102 .Ar encoding .
103 .It
104 If the first non-ASCII byte in the file introduces a valid UTF-8
105 sequence, input is interpreted as
106 .Cm utf-8 .
107 .It
108 Otherwise, input is interpreted as
109 .Cm iso-8859-1 .
110 .El
111 .It Fl mdoc | man
112 With
113 .Fl mdoc ,
114 all input files are interpreted as
115 .Xr mdoc 7 .
116 With
117 .Fl man ,
118 all input files are interpreted as
119 .Xr man 7 .
120 By default, the input language is automatically detected for each file:
121 if the the first macro is
122 .Ic \&Dd
123 or
124 .Ic \&Dt ,
125 the
126 .Xr mdoc 7
127 parser is used; otherwise, the
128 .Xr man 7
129 parser is used.
130 With other arguments,
131 .Fl m
132 is silently ignored.
133 .It Fl O Ar options
134 Comma-separated output options.
135 .It Fl T Ar output
136 Output format.
137 See
138 .Sx Output Formats
139 for available formats.
140 Defaults to
141 .Fl T Cm locale .
142 .It Fl W Ar level
143 Specify the minimum message
144 .Ar level
145 to be reported on the standard error output and to affect the exit status.
146 The
147 .Ar level
148 can be
149 .Cm style ,
150 .Cm warning ,
151 .Cm error ,
152 or
153 .Cm unsupp ;
154 .Cm all
155 is an alias for
156 .Cm style .
157 By default,
158 .Nm
159 is silent.
160 See
161 .Sx EXIT STATUS
162 and
163 .Sx DIAGNOSTICS
164 for details.
165 .Pp
166 The special option
167 .Fl W Cm stop
168 tells
169 .Nm
170 to exit after parsing a file that causes warnings or errors of at least
171 the requested level.
172 No formatted output will be produced from that file.
173 If both a
174 .Ar level
175 and
176 .Cm stop
177 are requested, they can be joined with a comma, for example
178 .Fl W Cm error , Ns Cm stop .
179 .It Ar file
180 Read input from zero or more files.
181 If unspecified, reads from stdin.
182 If multiple files are specified,
183 .Nm
184 will halt with the first failed parse.
185 .El
186 .Pp
187 The options
188 .Fl fhklw
189 are also supported and are documented in man(1).
190 In
191 .Fl f
192 and
193 .Fl k
194 mode,
195 .Nm
196 also supports the options
197 .Fl CMmOSs
198 described in the
199 .Xr apropos 1
200 manual.
201 The options
202 .Fl fkl
203 are mutually exclusive and override each other.
204 .Ss Output Formats
205 The
206 .Nm
207 utility accepts the following
208 .Fl T
209 arguments, which correspond to output modes:
210 .Bl -tag -width "-T markdown"
211 .It Fl T Cm ascii
212 Produce 7-bit ASCII output.
213 See
214 .Sx ASCII Output .
215 .It Fl T Cm html
216 Produce HTML5, CSS1, and MathML output.
217 See
218 .Sx HTML Output .
219 .It Fl T Cm lint
220 Parse only: produce no output.
221 Implies
222 .Fl W Cm warning .
223 .It Fl T Cm locale
224 Encode output using the current locale.
225 This is the default.
226 See
227 .Sx Locale Output .
228 .It Fl T Cm man
229 Produce
230 .Xr man 7
231 format output.
232 See
233 .Sx Man Output .
234 .It Fl T Cm markdown
235 Produce output in
236 .Sy markdown
237 format.
238 See
239 .Sx Markdown Output .
240 .It Fl T Cm pdf
241 Produce PDF output.
242 See
243 .Sx PDF Output .
244 .It Fl T Cm ps
245 Produce PostScript output.
246 See
247 .Sx PostScript Output .
248 .It Fl T Cm tree
249 Produce an indented parse tree.
250 See
251 .Sx Syntax tree output .
252 .It Fl T Cm utf8
253 Encode output in the UTF\-8 multi-byte format.
254 See
255 .Sx UTF\-8 Output .
256 .El
257 .Pp
258 If multiple input files are specified, these will be processed by the
259 corresponding filter in-order.
260 .Ss ASCII Output
261 Output produced by
262 .Fl T Cm ascii
263 is rendered in standard 7-bit ASCII documented in
264 .Xr ascii 7 .
265 .Pp
266 Font styles are applied by using back-spaced encoding such that an
267 underlined character
268 .Sq c
269 is rendered as
270 .Sq _ Ns \e[bs] Ns c ,
271 where
272 .Sq \e[bs]
273 is the back-space character number 8.
274 Emboldened characters are rendered as
275 .Sq c Ns \e[bs] Ns c .
276 .Pp
277 The special characters documented in
278 .Xr mandoc_char 7
279 are rendered best-effort in an ASCII equivalent.
280 .Pp
281 Output width is limited to 78 visible columns unless literal input lines
282 exceed this limit.
283 .Pp
284 The following
285 .Fl O
286 arguments are accepted:
287 .Bl -tag -width Ds
288 .It Cm indent Ns = Ns Ar indent
289 The left margin for normal text is set to
290 .Ar indent
291 blank characters instead of the default of five for
292 .Xr mdoc 7
293 and seven for
294 .Xr man 7 .
295 Increasing this is not recommended; it may result in degraded formatting,
296 for example overfull lines or ugly line breaks.
297 .It Cm width Ns = Ns Ar width
298 The output width is set to
299 .Ar width ,
300 which will normalise to \(>=58.
301 .El
302 .Ss HTML Output
303 Output produced by
304 .Fl T Cm html
305 conforms to HTML5 using optional self-closing tags.
306 Default styles use only CSS1.
307 Equations rendered from
308 .Xr eqn 7
309 blocks use MathML.
310 .Pp
311 The
312 .Pa mandoc.css
313 file documents style-sheet classes available for customising output.
314 If a style-sheet is not specified with
315 .Fl O Cm style ,
316 .Fl T Cm html
317 defaults to simple output (via an embedded style-sheet)
318 readable in any graphical or text-based web
319 browser.
320 .Pp
321 Special characters are rendered in decimal-encoded UTF\-8.
322 .Pp
323 The following
324 .Fl O
325 arguments are accepted:
326 .Bl -tag -width Ds
327 .It Cm fragment
328 Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
329 elements and only emit the subtree below the <body> element.
330 The
331 .Cm style
332 argument will be ignored.
333 This is useful when embedding manual content within existing documents.
334 .It Cm includes Ns = Ns Ar fmt
335 The string
336 .Ar fmt ,
337 for example,
338 .Ar ../src/%I.html ,
339 is used as a template for linked header files (usually via the
340 .Ic \&In
341 macro).
342 Instances of
343 .Sq \&%I
344 are replaced with the include filename.
345 The default is not to present a
346 hyperlink.
347 .It Cm man Ns = Ns Ar fmt
348 The string
349 .Ar fmt ,
350 for example,
351 .Ar ../html%S/%N.%S.html ,
352 is used as a template for linked manuals (usually via the
353 .Ic \&Xr
354 macro).
355 Instances of
356 .Sq \&%N
357 and
358 .Sq %S
359 are replaced with the linked manual's name and section, respectively.
360 If no section is included, section 1 is assumed.
361 The default is not to
362 present a hyperlink.
363 .It Cm style Ns = Ns Ar style.css
364 The file
365 .Ar style.css
366 is used for an external style-sheet.
367 This must be a valid absolute or
368 relative URI.
369 .El
370 .Ss Locale Output
371 Locale-depending output encoding is triggered with
372 .Fl T Cm locale .
373 This is the default.
374 .Pp
375 This option is not available on all systems: systems without locale
376 support, or those whose internal representation is not natively UCS-4,
377 will fall back to
378 .Fl T Cm ascii .
379 See
380 .Sx ASCII Output
381 for font style specification and available command-line arguments.
382 .Ss Man Output
383 Translate input format into
384 .Xr man 7
385 output format.
386 This is useful for distributing manual sources to legacy systems
387 lacking
388 .Xr mdoc 7
389 formatters.
390 .Pp
391 If
392 .Xr mdoc 7
393 is passed as input, it is translated into
394 .Xr man 7 .
395 If the input format is
396 .Xr man 7 ,
397 the input is copied to the output, expanding any
398 .Xr roff 7
399 .Ic so
400 requests.
401 The parser is also run, and as usual, the
402 .Fl W
403 level controls which
404 .Sx DIAGNOSTICS
405 are displayed before copying the input to the output.
406 .Ss Markdown Output
407 Translate
408 .Xr mdoc 7
409 input to the
410 .Sy markdown
411 format conforming to
412 .Lk http://daringfireball.net/projects/markdown/syntax.text\
413 "John Gruber's 2004 specification" .
414 The output also almost conforms to the
415 .Lk http://commonmark.org/ CommonMark
416 specification.
417 .Pp
418 The character set used for the markdown output is ASCII.
419 Non-ASCII characters are encoded as HTML entities.
420 Since that is not possible in literal font contexts, because these
421 are rendered as code spans and code blocks in the markdown output,
422 non-ASCII characters are transliterated to ASCII approximations in
423 these contexts.
424 .Pp
425 Markdown is a very weak markup language, so all semantic markup is
426 lost, and even part of the presentational markup may be lost.
427 Do not use this as an intermediate step in converting to HTML;
428 instead, use
429 .Fl T Cm html
430 directly.
431 .Pp
432 The
433 .Xr man 7 ,
434 .Xr tbl 7 ,
435 and
436 .Xr eqn 7
437 input languages are not supported by
438 .Fl T Cm markdown
439 output mode.
440 .Ss PDF Output
441 PDF-1.1 output may be generated by
442 .Fl T Cm pdf .
443 See
444 .Sx PostScript Output
445 for
446 .Fl O
447 arguments and defaults.
448 .Ss PostScript Output
449 PostScript
450 .Qq Adobe-3.0
451 Level-2 pages may be generated by
452 .Fl T Cm ps .
453 Output pages default to letter sized and are rendered in the Times font
454 family, 11-point.
455 Margins are calculated as 1/9 the page length and width.
456 Line-height is 1.4m.
457 .Pp
458 Special characters are rendered as in
459 .Sx ASCII Output .
460 .Pp
461 The following
462 .Fl O
463 arguments are accepted:
464 .Bl -tag -width Ds
465 .It Cm paper Ns = Ns Ar name
466 The paper size
467 .Ar name
468 may be one of
469 .Ar a3 ,
470 .Ar a4 ,
471 .Ar a5 ,
472 .Ar legal ,
473 or
474 .Ar letter .
475 You may also manually specify dimensions as
476 .Ar NNxNN ,
477 width by height in millimetres.
478 If an unknown value is encountered,
479 .Ar letter
480 is used.
481 .El
482 .Ss UTF\-8 Output
483 Use
484 .Fl T Cm utf8
485 to force a UTF\-8 locale.
486 See
487 .Sx Locale Output
488 for details and options.
489 .Ss Syntax tree output
490 Use
491 .Fl T Cm tree
492 to show a human readable representation of the syntax tree.
493 It is useful for debugging the source code of manual pages.
494 The exact format is subject to change, so don't write parsers for it.
495 .Pp
496 The first paragraph shows meta data found in the
497 .Xr mdoc 7
498 prologue, on the
499 .Xr man 7
500 .Ic \&TH
501 line, or the fallbacks used.
502 .Pp
503 In the tree dump, each output line shows one syntax tree node.
504 Child nodes are indented with respect to their parent node.
505 The columns are:
506 .Pp
507 .Bl -enum -compact
508 .It
509 For macro nodes, the macro name; for text and
510 .Xr tbl 7
511 nodes, the content.
512 There is a special format for
513 .Xr eqn 7
514 nodes.
515 .It
516 Node type (text, elem, block, head, body, body-end, tail, tbl, eqn).
517 .It
518 Flags:
519 .Bl -dash -compact
520 .It
521 An opening parenthesis if the node is an opening delimiter.
522 .It
523 An asterisk if the node starts a new input line.
524 .It
525 The input line number (starting at one).
526 .It
527 A colon.
528 .It
529 The input column number (starting at one).
530 .It
531 A closing parenthesis if the node is a closing delimiter.
532 .It
533 A full stop if the node ends a sentence.
534 .It
535 BROKEN if the node is a block broken by another block.
536 .It
537 NOSRC if the node is not in the input file,
538 but automatically generated from macros.
539 .It
540 NOPRT if the node is not supposed to generate output
541 for any output format.
542 .El
543 .El
544 .Pp
545 The following
546 .Fl O
547 argument is accepted:
548 .Bl -tag -width Ds
549 .It Cm noval
550 Skip validation and show the unvalidated syntax tree.
551 This can help to find out whether a given behaviour is caused by
552 the parser or by the validator.
553 Meta data is not available in this case.
554 .El
555 .Sh ENVIRONMENT
556 .Bl -tag -width MANPAGER
557 .It Ev MANPAGER
558 Any non-empty value of the environment variable
559 .Ev MANPAGER
560 is used instead of the standard pagination program,
561 .Xr more 1 ;
562 see
563 .Xr man 1
564 for details.
565 Only used if
566 .Fl a
567 or
568 .Fl l
569 is specified.
570 .It Ev PAGER
571 Specifies the pagination program to use when
572 .Ev MANPAGER
573 is not defined.
574 If neither PAGER nor MANPAGER is defined,
575 .Xr more 1
576 .Fl s
577 is used.
578 Only used if
579 .Fl a
580 or
581 .Fl l
582 is specified.
583 .El
584 .Sh EXIT STATUS
585 The
586 .Nm
587 utility exits with one of the following values, controlled by the message
588 .Ar level
589 associated with the
590 .Fl W
591 option:
592 .Pp
593 .Bl -tag -width Ds -compact
594 .It 0
595 No style suggestions, warnings or errors occurred, or those that
596 did were ignored because they were lower than the requested
597 .Ar level .
598 .It 1
599 At least one style suggestion occurred, but no warning or error, and
600 .Fl W Cm style
601 was specified.
602 .It 2
603 At least one warning occurred, but no error, and
604 .Fl W Cm warning
605 or
606 .Fl W Cm style
607 was specified.
608 .It 3
609 At least one parsing error occurred,
610 but no unsupported feature was encountered, and
611 .Fl W Cm error
612 or a lower
613 .Ar level
614 was requested.
615 .It 4
616 At least one unsupported feature was encountered, and
617 .Fl W Cm unsupp
618 or a lower
619 .Ar level
620 was requested.
621 .It 5
622 Invalid command line arguments were specified.
623 No input files have been read.
624 .It 6
625 An operating system error occurred, for example exhaustion
626 of memory, file descriptors, or process table entries.
627 Such errors cause
628 .Nm
629 to exit at once, possibly in the middle of parsing or formatting a file.
630 .El
631 .Pp
632 Note that selecting
633 .Fl T Cm lint
634 output mode implies
635 .Fl W Cm warning .
636 .Sh EXAMPLES
637 To page manuals to the terminal:
638 .Pp
639 .Dl $ mandoc -l mandoc.1 man.1 apropos.1 makewhatis.8
640 .Pp
641 To produce HTML manuals with
642 .Pa mandoc.css
643 as the style-sheet:
644 .Pp
645 .Dl $ mandoc \-T html -O style=mandoc.css mdoc.7 \*(Gt mdoc.7.html
646 .Pp
647 To check over a large set of manuals:
648 .Pp
649 .Dl $ mandoc \-T lint \(gafind /usr/src -name \e*\e.[1-9]\(ga
650 .Pp
651 To produce a series of PostScript manuals for A4 paper:
652 .Pp
653 .Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
654 .Pp
655 Convert a modern
656 .Xr mdoc 7
657 manual to the older
658 .Xr man 7
659 format, for use on systems lacking an
660 .Xr mdoc 7
661 parser:
662 .Pp
663 .Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
664 .Sh DIAGNOSTICS
665 Messages displayed by
666 .Nm
667 follow this format:
668 .Pp
669 .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
670 .Pp
671 Line and column numbers start at 1.
672 Both are omitted for messages referring to an input file as a whole.
673 Macro names and arguments are omitted where meaningless.
674 Fatal messages about invalid command line arguments
675 or operating system errors, for example when memory is exhausted,
676 may also omit the
677 .Ar file
678 and
679 .Ar level
680 fields.
681 .Pp
682 Message levels have the following meanings:
683 .Bl -tag -width "warning"
684 .It Cm unsupp
685 An input file uses unsupported low-level
686 .Xr roff 7
687 features.
688 The output may be incomplete and/or misformatted,
689 so using GNU troff instead of
690 .Nm
691 to process the file may be preferable.
692 .It Cm error
693 An input file contains invalid syntax that cannot be safely interpreted.
694 By discarding part of the input or inserting missing tokens,
695 the parser is able to continue, and the error does not prevent
696 generation of formatted output, but typically, preparing that
697 output involves information loss, broken document structure
698 or unintended formatting, no matter whether
699 .Nm
700 or GNU troff is used.
701 In many cases, the output of
702 .Nm
703 and GNU troff is identical, but in some,
704 .Nm
705 is more resilient than GNU troff with respect to malformed input.
706 .Pp
707 Non-existent or unreadable input files are also reported on the
708 .Cm error
709 level.
710 In that case, the parser cannot even be started and no output
711 is produced from those input files.
712 .It Cm warning
713 An input file uses obsolete, discouraged or non-portable syntax.
714 All the same, the meaning of the input is unambiguous and a correct
715 rendering can be produced.
716 Documents causing warnings may render poorly when using other
717 formatting tools instead of
718 .Nm .
719 .It Cm style
720 An input file uses dubious or discouraged style.
721 This is not a complaint about the syntax, and probably neither
722 formatting nor portability are in danger.
723 While great care is taken to avoid false positives on the higher
724 message levels, the
725 .Cm style
726 level tries to reduce the probability that issues go unnoticed,
727 so it may occasionally issue bogus suggestions.
728 Please use your good judgement to decide whether any particular
729 .Cm style
730 suggestion really justifies a change to the input file.
731 .El
732 .Pp
733 Messages of the
734 .Cm style ,
735 .Cm warning ,
736 .Cm error ,
737 and
738 .Cm unsupp
739 levels except those about non-existent or unreadable input files
740 are hidden unless their level, or a lower level, is requested using a
741 .Fl W
742 option or
743 .Fl T Cm lint
744 output mode.
745 .Ss Style messages
746 .Bl -ohang
747 .It Sy "useless macro"
748 .Pq mdoc
749 A
750 .Ic \&Bt ,
751 .Ic \&Tn ,
752 or
753 .Ic \Ud
754 macro was found.
755 Simply delete it, it serves no useful purpose.
756 .El
757 .Ss Warnings related to the document prologue
758 .Bl -ohang
759 .It Sy "missing manual title, using UNTITLED"
760 .Pq mdoc
761 A
762 .Ic \&Dt
763 macro has no arguments, or there is no
764 .Ic \&Dt
765 macro before the first non-prologue macro.
766 .It Sy "missing manual title, using \(dq\(dq"
767 .Pq man
768 There is no
769 .Ic \&TH
770 macro, or it has no arguments.
771 .It Sy "lower case character in document title"
772 .Pq mdoc , man
773 The title is still used as given in the
774 .Ic \&Dt
775 or
776 .Ic \&TH
777 macro.
778 .It Sy "missing manual section, using \(dq\(dq"
779 .Pq mdoc , man
780 A
781 .Ic \&Dt
782 or
783 .Ic \&TH
784 macro lacks the mandatory section argument.
785 .It Sy "unknown manual section"
786 .Pq mdoc
787 The section number in a
788 .Ic \&Dt
789 line is invalid, but still used.
790 .It Sy "missing date, using today's date"
791 .Pq mdoc, man
792 The document was parsed as
793 .Xr mdoc 7
794 and it has no
795 .Ic \&Dd
796 macro, or the
797 .Ic \&Dd
798 macro has no arguments or only empty arguments;
799 or the document was parsed as
800 .Xr man 7
801 and it has no
802 .Ic \&TH
803 macro, or the
804 .Ic \&TH
805 macro has less than three arguments or its third argument is empty.
806 .It Sy "cannot parse date, using it verbatim"
807 .Pq mdoc , man
808 The date given in a
809 .Ic \&Dd
810 or
811 .Ic \&TH
812 macro does not follow the conventional format.
813 .It Sy "missing Os macro, using \(dq\(dq"
814 .Pq mdoc
815 The default or current system is not shown in this case.
816 .It Sy "duplicate prologue macro"
817 .Pq mdoc
818 One of the prologue macros occurs more than once.
819 The last instance overrides all previous ones.
820 .It Sy "late prologue macro"
821 .Pq mdoc
822 A
823 .Ic \&Dd
824 or
825 .Ic \&Os
826 macro occurs after some non-prologue macro, but still takes effect.
827 .It Sy "skipping late title macro"
828 .Pq mdoc
829 The
830 .Ic \&Dt
831 macro appears after the first non-prologue macro.
832 Traditional formatters cannot handle this because
833 they write the page header before parsing the document body.
834 Even though this technical restriction does not apply to
835 .Nm ,
836 traditional semantics is preserved.
837 The late macro is discarded including its arguments.
838 .It Sy "prologue macros out of order"
839 .Pq mdoc
840 The prologue macros are not given in the conventional order
841 .Ic \&Dd ,
842 .Ic \&Dt ,
843 .Ic \&Os .
844 All three macros are used even when given in another order.
845 .El
846 .Ss Warnings regarding document structure
847 .Bl -ohang
848 .It Sy ".so is fragile, better use ln(1)"
849 .Pq roff
850 Including files only works when the parser program runs with the correct
851 current working directory.
852 .It Sy "no document body"
853 .Pq mdoc , man
854 The document body contains neither text nor macros.
855 An empty document is shown, consisting only of a header and a footer line.
856 .It Sy "content before first section header"
857 .Pq mdoc , man
858 Some macros or text precede the first
859 .Ic \&Sh
860 or
861 .Ic \&SH
862 section header.
863 The offending macros and text are parsed and added to the top level
864 of the syntax tree, outside any section block.
865 .It Sy "first section is not NAME"
866 .Pq mdoc
867 The argument of the first
868 .Ic \&Sh
869 macro is not
870 .Sq NAME .
871 This may confuse
872 .Xr makewhatis 8
873 and
874 .Xr apropos 1 .
875 .It Sy "NAME section without Nm before Nd"
876 .Pq mdoc
877 The NAME section does not contain any
878 .Ic \&Nm
879 child macro before the first
880 .Ic \&Nd
881 macro.
882 .It Sy "NAME section without description"
883 .Pq mdoc
884 The NAME section lacks the mandatory
885 .Ic \&Nd
886 child macro.
887 .It Sy "description not at the end of NAME"
888 .Pq mdoc
889 The NAME section does contain an
890 .Ic \&Nd
891 child macro, but other content follows it.
892 .It Sy "bad NAME section content"
893 .Pq mdoc
894 The NAME section contains plain text or macros other than
895 .Ic \&Nm
896 and
897 .Ic \&Nd .
898 .It Sy "missing comma before name"
899 .Pq mdoc
900 The NAME section contains an
901 .Ic \&Nm
902 macro that is neither the first one nor preceded by a comma.
903 .It Sy "missing description line, using \(dq\(dq"
904 .Pq mdoc
905 The
906 .Ic \&Nd
907 macro lacks the required argument.
908 The title line of the manual will end after the dash.
909 .It Sy "description line outside NAME section"
910 .Pq mdoc
911 An
912 .Ic \&Nd
913 macro appears outside the NAME section.
914 The arguments are printed anyway and the following text is used for
915 .Xr apropos 1 ,
916 but none of that behaviour is portable.
917 .It Sy "sections out of conventional order"
918 .Pq mdoc
919 A standard section occurs after another section it usually precedes.
920 All section titles are used as given,
921 and the order of sections is not changed.
922 .It Sy "duplicate section title"
923 .Pq mdoc
924 The same standard section title occurs more than once.
925 .It Sy "unexpected section"
926 .Pq mdoc
927 A standard section header occurs in a section of the manual
928 where it normally isn't useful.
929 .It Sy "unusual Xr order"
930 .Pq mdoc
931 In the SEE ALSO section, an
932 .Ic \&Xr
933 macro with a lower section number follows one with a higher number,
934 or two
935 .Ic \&Xr
936 macros referring to the same section are out of alphabetical order.
937 .It Sy "unusual Xr punctuation"
938 .Pq mdoc
939 In the SEE ALSO section, punctuation between two
940 .Ic \&Xr
941 macros differs from a single comma, or there is trailing punctuation
942 after the last
943 .Ic \&Xr
944 macro.
945 .It Sy "AUTHORS section without An macro"
946 .Pq mdoc
947 An AUTHORS sections contains no
948 .Ic \&An
949 macros, or only empty ones.
950 Probably, there are author names lacking markup.
951 .El
952 .Ss "Warnings related to macros and nesting"
953 .Bl -ohang
954 .It Sy "obsolete macro"
955 .Pq mdoc
956 See the
957 .Xr mdoc 7
958 manual for replacements.
959 .It Sy "macro neither callable nor escaped"
960 .Pq mdoc
961 The name of a macro that is not callable appears on a macro line.
962 It is printed verbatim.
963 If the intention is to call it, move it to its own input line;
964 otherwise, escape it by prepending
965 .Sq \e& .
966 .It Sy "skipping paragraph macro"
967 In
968 .Xr mdoc 7
969 documents, this happens
970 .Bl -dash -compact
971 .It
972 at the beginning and end of sections and subsections
973 .It
974 right before non-compact lists and displays
975 .It
976 at the end of items in non-column, non-compact lists
977 .It
978 and for multiple consecutive paragraph macros.
979 .El
980 In
981 .Xr man 7
982 documents, it happens
983 .Bl -dash -compact
984 .It
985 for empty
986 .Ic \&P ,
987 .Ic \&PP ,
988 and
989 .Ic \&LP
990 macros
991 .It
992 for
993 .Ic \&IP
994 macros having neither head nor body arguments
995 .It
996 for
997 .Ic \&br
998 or
999 .Ic \&sp
1000 right after
1001 .Ic \&SH
1002 or
1003 .Ic \&SS
1004 .El
1005 .It Sy "moving paragraph macro out of list"
1006 .Pq mdoc
1007 A list item in a
1008 .Ic \&Bl
1009 list contains a trailing paragraph macro.
1010 The paragraph macro is moved after the end of the list.
1011 .It Sy "skipping no-space macro"
1012 .Pq mdoc
1013 An input line begins with an
1014 .Ic \&Ns
1015 macro.
1016 The macro is ignored.
1017 .It Sy "blocks badly nested"
1018 .Pq mdoc
1019 If two blocks intersect, one should completely contain the other.
1020 Otherwise, rendered output is likely to look strange in any output
1021 format, and rendering in SGML-based output formats is likely to be
1022 outright wrong because such languages do not support badly nested
1023 blocks at all.
1024 Typical examples of badly nested blocks are
1025 .Qq Ic \&Ao \&Bo \&Ac \&Bc
1026 and
1027 .Qq Ic \&Ao \&Bq \&Ac .
1028 In these examples,
1029 .Ic \&Ac
1030 breaks
1031 .Ic \&Bo
1032 and
1033 .Ic \&Bq ,
1034 respectively.
1035 .It Sy "nested displays are not portable"
1036 .Pq mdoc
1037 A
1038 .Ic \&Bd ,
1039 .Ic \&D1 ,
1040 or
1041 .Ic \&Dl
1042 display occurs nested inside another
1043 .Ic \&Bd
1044 display.
1045 This works with
1046 .Nm ,
1047 but fails with most other implementations.
1048 .It Sy "moving content out of list"
1049 .Pq mdoc
1050 A
1051 .Ic \&Bl
1052 list block contains text or macros before the first
1053 .Ic \&It
1054 macro.
1055 The offending children are moved before the beginning of the list.
1056 .It Sy "fill mode already enabled, skipping"
1057 .Pq man
1058 A
1059 .Ic \&fi
1060 request occurs even though the document is still in fill mode,
1061 or already switched back to fill mode.
1062 It has no effect.
1063 .It Sy "fill mode already disabled, skipping"
1064 .Pq man
1065 An
1066 .Ic \&nf
1067 request occurs even though the document already switched to no-fill mode
1068 and did not switch back to fill mode yet.
1069 It has no effect.
1070 .It Sy "line scope broken"
1071 .Pq man
1072 While parsing the next-line scope of the previous macro,
1073 another macro is found that prematurely terminates the previous one.
1074 The previous, interrupted macro is deleted from the parse tree.
1075 .El
1076 .Ss "Warnings related to missing arguments"
1077 .Bl -ohang
1078 .It Sy "skipping empty request"
1079 .Pq roff , eqn
1080 The macro name is missing from a macro definition request,
1081 or an
1082 .Xr eqn 7
1083 control statement or operation keyword lacks its required argument.
1084 .It Sy "conditional request controls empty scope"
1085 .Pq roff
1086 A conditional request is only useful if any of the following
1087 follows it on the same logical input line:
1088 .Bl -dash -compact
1089 .It
1090 The
1091 .Sq \e{
1092 keyword to open a multi-line scope.
1093 .It
1094 A request or macro or some text, resulting in a single-line scope.
1095 .It
1096 The immediate end of the logical line without any intervening whitespace,
1097 resulting in next-line scope.
1098 .El
1099 Here, a conditional request is followed by trailing whitespace only,
1100 and there is no other content on its logical input line.
1101 Note that it doesn't matter whether the logical input line is split
1102 across multiple physical input lines using
1103 .Sq \e
1104 line continuation characters.
1105 This is one of the rare cases
1106 where trailing whitespace is syntactically significant.
1107 The conditional request controls a scope containing whitespace only,
1108 so it is unlikely to have a significant effect,
1109 except that it may control a following
1110 .Ic \&el
1111 clause.
1112 .It Sy "skipping empty macro"
1113 .Pq mdoc
1114 The indicated macro has no arguments and hence no effect.
1115 .It Sy "empty block"
1116 .Pq mdoc , man
1117 A
1118 .Ic \&Bd ,
1119 .Ic \&Bk ,
1120 .Ic \&Bl ,
1121 .Ic \&D1 ,
1122 .Ic \&Dl ,
1123 .Ic \&RS ,
1124 or
1125 .Ic \&UR
1126 block contains nothing in its body and will produce no output.
1127 .It Sy "empty argument, using 0n"
1128 .Pq mdoc
1129 The required width is missing after
1130 .Ic \&Bd
1131 or
1132 .Ic \&Bl
1133 .Fl offset
1134 or
1135 .Fl width .
1136 .It Sy "missing display type, using -ragged"
1137 .Pq mdoc
1138 The
1139 .Ic \&Bd
1140 macro is invoked without the required display type.
1141 .It Sy "list type is not the first argument"
1142 .Pq mdoc
1143 In a
1144 .Ic \&Bl
1145 macro, at least one other argument precedes the type argument.
1146 The
1147 .Nm
1148 utility copes with any argument order, but some other
1149 .Xr mdoc 7
1150 implementations do not.
1151 .It Sy "missing -width in -tag list, using 8n"
1152 .Pq mdoc
1153 Every
1154 .Ic \&Bl
1155 macro having the
1156 .Fl tag
1157 argument requires
1158 .Fl width ,
1159 too.
1160 .It Sy "missing utility name, using \(dq\(dq"
1161 .Pq mdoc
1162 The
1163 .Ic \&Ex Fl std
1164 macro is called without an argument before
1165 .Ic \&Nm
1166 has first been called with an argument.
1167 .It Sy "missing function name, using \(dq\(dq"
1168 .Pq mdoc
1169 The
1170 .Ic \&Fo
1171 macro is called without an argument.
1172 No function name is printed.
1173 .It Sy "empty head in list item"
1174 .Pq mdoc
1175 In a
1176 .Ic \&Bl
1177 .Fl diag ,
1178 .Fl hang ,
1179 .Fl inset ,
1180 .Fl ohang ,
1181 or
1182 .Fl tag
1183 list, an
1184 .Ic \&It
1185 macro lacks the required argument.
1186 The item head is left empty.
1187 .It Sy "empty list item"
1188 .Pq mdoc
1189 In a
1190 .Ic \&Bl
1191 .Fl bullet ,
1192 .Fl dash ,
1193 .Fl enum ,
1194 or
1195 .Fl hyphen
1196 list, an
1197 .Ic \&It
1198 block is empty.
1199 An empty list item is shown.
1200 .It Sy "missing font type, using \efR"
1201 .Pq mdoc
1202 A
1203 .Ic \&Bf
1204 macro has no argument.
1205 It switches to the default font.
1206 .It Sy "unknown font type, using \efR"
1207 .Pq mdoc
1208 The
1209 .Ic \&Bf
1210 argument is invalid.
1211 The default font is used instead.
1212 .It Sy "nothing follows prefix"
1213 .Pq mdoc
1214 A
1215 .Ic \&Pf
1216 macro has no argument, or only one argument and no macro follows
1217 on the same input line.
1218 This defeats its purpose; in particular, spacing is not suppressed
1219 before the text or macros following on the next input line.
1220 .It Sy "empty reference block"
1221 .Pq mdoc
1222 An
1223 .Ic \&Rs
1224 macro is immediately followed by an
1225 .Ic \&Re
1226 macro on the next input line.
1227 Such an empty block does not produce any output.
1228 .It Sy "missing section argument"
1229 .Pq mdoc
1230 An
1231 .Ic \&Xr
1232 macro lacks its second, section number argument.
1233 The first argument, i.e. the name, is printed, but without subsequent
1234 parentheses.
1235 .It Sy "missing -std argument, adding it"
1236 .Pq mdoc
1237 An
1238 .Ic \&Ex
1239 or
1240 .Ic \&Rv
1241 macro lacks the required
1242 .Fl std
1243 argument.
1244 The
1245 .Nm
1246 utility assumes
1247 .Fl std
1248 even when it is not specified, but other implementations may not.
1249 .It Sy "missing option string, using \(dq\(dq"
1250 .Pq man
1251 The
1252 .Ic \&OP
1253 macro is invoked without any argument.
1254 An empty pair of square brackets is shown.
1255 .It Sy "missing resource identifier, using \(dq\(dq"
1256 .Pq man
1257 The
1258 .Ic \&UR
1259 macro is invoked without any argument.
1260 An empty pair of angle brackets is shown.
1261 .It Sy "missing eqn box, using \(dq\(dq"
1262 .Pq eqn
1263 A diacritic mark or a binary operator is found,
1264 but there is nothing to the left of it.
1265 An empty box is inserted.
1266 .El
1267 .Ss "Warnings related to bad macro arguments"
1268 .Bl -ohang
1269 .It Sy "unterminated quoted argument"
1270 .Pq roff
1271 Macro arguments can be enclosed in double quote characters
1272 such that space characters and macro names contained in the quoted
1273 argument need not be escaped.
1274 The closing quote of the last argument of a macro can be omitted.
1275 However, omitting it is not recommended because it makes the code
1276 harder to read.
1277 .It Sy "duplicate argument"
1278 .Pq mdoc
1279 A
1280 .Ic \&Bd
1281 or
1282 .Ic \&Bl
1283 macro has more than one
1284 .Fl compact ,
1285 more than one
1286 .Fl offset ,
1287 or more than one
1288 .Fl width
1289 argument.
1290 All but the last instances of these arguments are ignored.
1291 .It Sy "skipping duplicate argument"
1292 .Pq mdoc
1293 An
1294 .Ic \&An
1295 macro has more than one
1296 .Fl split
1297 or
1298 .Fl nosplit
1299 argument.
1300 All but the first of these arguments are ignored.
1301 .It Sy "skipping duplicate display type"
1302 .Pq mdoc
1303 A
1304 .Ic \&Bd
1305 macro has more than one type argument; the first one is used.
1306 .It Sy "skipping duplicate list type"
1307 .Pq mdoc
1308 A
1309 .Ic \&Bl
1310 macro has more than one type argument; the first one is used.
1311 .It Sy "skipping -width argument"
1312 .Pq mdoc
1313 A
1314 .Ic \&Bl
1315 .Fl column ,
1316 .Fl diag ,
1317 .Fl ohang ,
1318 .Fl inset ,
1319 or
1320 .Fl item
1321 list has a
1322 .Fl width
1323 argument.
1324 That has no effect.
1325 .It Sy "wrong number of cells"
1326 In a line of a
1327 .Ic \&Bl Fl column
1328 list, the number of tabs or
1329 .Ic \&Ta
1330 macros is less than the number expected from the list header line
1331 or exceeds the expected number by more than one.
1332 Missing cells remain empty, and all cells exceeding the number of
1333 columns are joined into one single cell.
1334 .It Sy "unknown AT&T UNIX version"
1335 .Pq mdoc
1336 An
1337 .Ic \&At
1338 macro has an invalid argument.
1339 It is used verbatim, with
1340 .Qq "AT&T UNIX "
1341 prefixed to it.
1342 .It Sy "comma in function argument"
1343 .Pq mdoc
1344 An argument of an
1345 .Ic \&Fa
1346 or
1347 .Ic \&Fn
1348 macro contains a comma; it should probably be split into two arguments.
1349 .It Sy "parenthesis in function name"
1350 .Pq mdoc
1351 The first argument of an
1352 .Ic \&Fc
1353 or
1354 .Ic \&Fn
1355 macro contains an opening or closing parenthesis; that's probably wrong,
1356 parentheses are added automatically.
1357 .It Sy "invalid content in Rs block"
1358 .Pq mdoc
1359 An
1360 .Ic \&Rs
1361 block contains plain text or non-% macros.
1362 The bogus content is left in the syntax tree.
1363 Formatting may be poor.
1364 .It Sy "invalid Boolean argument"
1365 .Pq mdoc
1366 An
1367 .Ic \&Sm
1368 macro has an argument other than
1369 .Cm on
1370 or
1371 .Cm off .
1372 The invalid argument is moved out of the macro, which leaves the macro
1373 empty, causing it to toggle the spacing mode.
1374 .It Sy "unknown font, skipping request"
1375 .Pq man , tbl
1376 A
1377 .Xr roff 7
1378 .Ic \&ft
1379 request or a
1380 .Xr tbl 7
1381 .Ic \&f
1382 layout modifier has an unknown
1383 .Ar font
1384 argument.
1385 .It Sy "odd number of characters in request"
1386 .Pq roff
1387 A
1388 .Ic \&tr
1389 request contains an odd number of characters.
1390 The last character is mapped to the blank character.
1391 .El
1392 .Ss "Warnings related to plain text"
1393 .Bl -ohang
1394 .It Sy "blank line in fill mode, using .sp"
1395 .Pq mdoc
1396 The meaning of blank input lines is only well-defined in non-fill mode:
1397 In fill mode, line breaks of text input lines are not supposed to be
1398 significant.
1399 However, for compatibility with groff, blank lines in fill mode
1400 are replaced with
1401 .Ic \&sp
1402 requests.
1403 .It Sy "tab in filled text"
1404 .Pq mdoc , man
1405 The meaning of tab characters is only well-defined in non-fill mode:
1406 In fill mode, whitespace is not supposed to be significant
1407 on text input lines.
1408 As an implementation dependent choice, tab characters on text lines
1409 are passed through to the formatters in any case.
1410 Given that the text before the tab character will be filled,
1411 it is hard to predict which tab stop position the tab will advance to.
1412 .It Sy "whitespace at end of input line"
1413 .Pq mdoc , man , roff
1414 Whitespace at the end of input lines is almost never semantically
1415 significant \(em but in the odd case where it might be, it is
1416 extremely confusing when reviewing and maintaining documents.
1417 .It Sy "new sentence, new line"
1418 .Pq mdoc
1419 A new sentence starts in the middle of a text line.
1420 Start it on a new input line to help formatters produce correct spacing.
1421 .It Sy "bad comment style"
1422 .Pq roff
1423 Comment lines start with a dot, a backslash, and a double-quote character.
1424 The
1425 .Nm
1426 utility treats the line as a comment line even without the backslash,
1427 but leaving out the backslash might not be portable.
1428 .It Sy "invalid escape sequence"
1429 .Pq roff
1430 An escape sequence has an invalid opening argument delimiter, lacks the
1431 closing argument delimiter, or the argument has too few characters.
1432 If the argument is incomplete,
1433 .Ic \e*
1434 and
1435 .Ic \en
1436 expand to an empty string,
1437 .Ic \eB
1438 to the digit
1439 .Sq 0 ,
1440 and
1441 .Ic \ew
1442 to the length of the incomplete argument.
1443 All other invalid escape sequences are ignored.
1444 .It Sy "undefined string, using \(dq\(dq"
1445 .Pq roff
1446 If a string is used without being defined before,
1447 its value is implicitly set to the empty string.
1448 However, defining strings explicitly before use
1449 keeps the code more readable.
1450 .El
1451 .Ss "Warnings related to tables"
1452 .Bl -ohang
1453 .It Sy "tbl line starts with span"
1454 .Pq tbl
1455 The first cell in a table layout line is a horizontal span
1456 .Pq Sq Cm s .
1457 Data provided for this cell is ignored, and nothing is printed in the cell.
1458 .It Sy "tbl column starts with span"
1459 .Pq tbl
1460 The first line of a table layout specification
1461 requests a vertical span
1462 .Pq Sq Cm ^ .
1463 Data provided for this cell is ignored, and nothing is printed in the cell.
1464 .It Sy "skipping vertical bar in tbl layout"
1465 .Pq tbl
1466 A table layout specification contains more than two consecutive vertical bars.
1467 A double bar is printed, all additional bars are discarded.
1468 .El
1469 .Ss "Errors related to tables"
1470 .Bl -ohang
1471 .It Sy "non-alphabetic character in tbl options"
1472 .Pq tbl
1473 The table options line contains a character other than a letter,
1474 blank, or comma where the beginning of an option name is expected.
1475 The character is ignored.
1476 .It Sy "skipping unknown tbl option"
1477 .Pq tbl
1478 The table options line contains a string of letters that does not
1479 match any known option name.
1480 The word is ignored.
1481 .It Sy "missing tbl option argument"
1482 .Pq tbl
1483 A table option that requires an argument is not followed by an
1484 opening parenthesis, or the opening parenthesis is immediately
1485 followed by a closing parenthesis.
1486 The option is ignored.
1487 .It Sy "wrong tbl option argument size"
1488 .Pq tbl
1489 A table option argument contains an invalid number of characters.
1490 Both the option and the argument are ignored.
1491 .It Sy "empty tbl layout"
1492 .Pq tbl
1493 A table layout specification is completely empty,
1494 specifying zero lines and zero columns.
1495 As a fallback, a single left-justified column is used.
1496 .It Sy "invalid character in tbl layout"
1497 .Pq tbl
1498 A table layout specification contains a character that can neither
1499 be interpreted as a layout key character nor as a layout modifier,
1500 or a modifier precedes the first key.
1501 The invalid character is discarded.
1502 .It Sy "unmatched parenthesis in tbl layout"
1503 .Pq tbl
1504 A table layout specification contains an opening parenthesis,
1505 but no matching closing parenthesis.
1506 The rest of the input line, starting from the parenthesis, has no effect.
1507 .It Sy "tbl without any data cells"
1508 .Pq tbl
1509 A table does not contain any data cells.
1510 It will probably produce no output.
1511 .It Sy "ignoring data in spanned tbl cell"
1512 .Pq tbl
1513 A table cell is marked as a horizontal span
1514 .Pq Sq Cm s
1515 or vertical span
1516 .Pq Sq Cm ^
1517 in the table layout, but it contains data.
1518 The data is ignored.
1519 .It Sy "ignoring extra tbl data cells"
1520 .Pq tbl
1521 A data line contains more cells than the corresponding layout line.
1522 The data in the extra cells is ignored.
1523 .It Sy "data block open at end of tbl"
1524 .Pq tbl
1525 A data block is opened with
1526 .Cm T{ ,
1527 but never closed with a matching
1528 .Cm T} .
1529 The remaining data lines of the table are all put into one cell,
1530 and any remaining cells stay empty.
1531 .El
1532 .Ss "Errors related to roff, mdoc, and man code"
1533 .Bl -ohang
1534 .It Sy "input stack limit exceeded, infinite loop?"
1535 .Pq roff
1536 Explicit recursion limits are implemented for the following features,
1537 in order to prevent infinite loops:
1538 .Bl -dash -compact
1539 .It
1540 expansion of nested escape sequences
1541 including expansion of strings and number registers,
1542 .It
1543 expansion of nested user-defined macros,
1544 .It
1545 and
1546 .Ic \&so
1547 file inclusion.
1548 .El
1549 When a limit is hit, the output is incorrect, typically losing
1550 some content, but the parser can continue.
1551 .It Sy "skipping bad character"
1552 .Pq mdoc , man , roff
1553 The input file contains a byte that is not a printable
1554 .Xr ascii 7
1555 character.
1556 The message mentions the character number.
1557 The offending byte is replaced with a question mark
1558 .Pq Sq \&? .
1559 Consider editing the input file to replace the byte with an ASCII
1560 transliteration of the intended character.
1561 .It Sy "skipping unknown macro"
1562 .Pq mdoc , man , roff
1563 The first identifier on a request or macro line is neither recognized as a
1564 .Xr roff 7
1565 request, nor as a user-defined macro, nor, respectively, as an
1566 .Xr mdoc 7
1567 or
1568 .Xr man 7
1569 macro.
1570 It may be mistyped or unsupported.
1571 The request or macro is discarded including its arguments.
1572 .It Sy "skipping insecure request"
1573 .Pq roff
1574 An input file attempted to run a shell command
1575 or to read or write an external file.
1576 Such attempts are denied for security reasons.
1577 .It Sy "skipping item outside list"
1578 .Pq mdoc , eqn
1579 An
1580 .Ic \&It
1581 macro occurs outside any
1582 .Ic \&Bl
1583 list, or an
1584 .Xr eqn 7
1585 .Ic above
1586 delimiter occurs outside any pile.
1587 It is discarded including its arguments.
1588 .It Sy "skipping column outside column list"
1589 .Pq mdoc
1590 A
1591 .Ic \&Ta
1592 macro occurs outside any
1593 .Ic \&Bl Fl column
1594 block.
1595 It is discarded including its arguments.
1596 .It Sy "skipping end of block that is not open"
1597 .Pq mdoc , man , eqn , tbl , roff
1598 Various syntax elements can only be used to explicitly close blocks
1599 that have previously been opened.
1600 An
1601 .Xr mdoc 7
1602 block closing macro, a
1603 .Xr man 7
1604 .Ic \&RE
1605 or
1606 .Ic \&UE
1607 macro, an
1608 .Xr eqn 7
1609 right delimiter or closing brace, or the end of an equation, table, or
1610 .Xr roff 7
1611 conditional request is encountered but no matching block is open.
1612 The offending request or macro is discarded.
1613 .It Sy "fewer RS blocks open, skipping"
1614 .Pq man
1615 The
1616 .Ic \&RE
1617 macro is invoked with an argument, but less than the specified number of
1618 .Ic \&RS
1619 blocks is open.
1620 The
1621 .Ic \&RE
1622 macro is discarded.
1623 .It Sy "inserting missing end of block"
1624 .Pq mdoc , tbl
1625 Various
1626 .Xr mdoc 7
1627 macros as well as tables require explicit closing by dedicated macros.
1628 A block that doesn't support bad nesting
1629 ends before all of its children are properly closed.
1630 The open child nodes are closed implicitly.
1631 .It Sy "appending missing end of block"
1632 .Pq mdoc , man , eqn , tbl , roff
1633 At the end of the document, an explicit
1634 .Xr mdoc 7
1635 block, a
1636 .Xr man 7
1637 next-line scope or
1638 .Ic \&RS
1639 or
1640 .Ic \&UR
1641 block, an equation, table, or
1642 .Xr roff 7
1643 conditional or ignore block is still open.
1644 The open block is closed implicitly.
1645 .It Sy "escaped character not allowed in a name"
1646 .Pq roff
1647 Macro, string and register identifiers consist of printable,
1648 non-whitespace ASCII characters.
1649 Escape sequences and characters and strings expressed in terms of them
1650 cannot form part of a name.
1651 The first argument of an
1652 .Ic \&am ,
1653 .Ic \&as ,
1654 .Ic \&de ,
1655 .Ic \&ds ,
1656 .Ic \&nr ,
1657 or
1658 .Ic \&rr
1659 request, or any argument of an
1660 .Ic \&rm
1661 request, or the name of a request or user defined macro being called,
1662 is terminated by an escape sequence.
1663 In the cases of
1664 .Ic \&as ,
1665 .Ic \&ds ,
1666 and
1667 .Ic \&nr ,
1668 the request has no effect at all.
1669 In the cases of
1670 .Ic \&am ,
1671 .Ic \&de ,
1672 .Ic \&rr ,
1673 and
1674 .Ic \&rm ,
1675 what was parsed up to this point is used as the arguments to the request,
1676 and the rest of the input line is discarded including the escape sequence.
1677 When parsing for a request or a user-defined macro name to be called,
1678 only the escape sequence is discarded.
1679 The characters preceding it are used as the request or macro name,
1680 the characters following it are used as the arguments to the request or macro.
1681 .It Sy "NOT IMPLEMENTED: Bd -file"
1682 .Pq mdoc
1683 For security reasons, the
1684 .Ic \&Bd
1685 macro does not support the
1686 .Fl file
1687 argument.
1688 By requesting the inclusion of a sensitive file, a malicious document
1689 might otherwise trick a privileged user into inadvertently displaying
1690 the file on the screen, revealing the file content to bystanders.
1691 The argument is ignored including the file name following it.
1692 .It Sy "skipping display without arguments"
1693 .Pq mdoc
1694 A
1695 .Ic \&Bd
1696 block macro does not have any arguments.
1697 The block is discarded, and the block content is displayed in
1698 whatever mode was active before the block.
1699 .It Sy "missing list type, using -item"
1700 .Pq mdoc
1701 A
1702 .Ic \&Bl
1703 macro fails to specify the list type.
1704 .It Sy "missing manual name, using \(dq\(dq"
1705 .Pq mdoc
1706 The first call to
1707 .Ic \&Nm ,
1708 or any call in the NAME section, lacks the required argument.
1709 .It Sy "uname(3) system call failed, using UNKNOWN"
1710 .Pq mdoc
1711 The
1712 .Ic \&Os
1713 macro is called without arguments, and the
1714 .Xr uname 3
1715 system call failed.
1716 As a workaround,
1717 .Nm
1718 can be compiled with
1719 .Sm off
1720 .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
1721 .Sm on
1722 .It Sy "unknown standard specifier"
1723 .Pq mdoc
1724 An
1725 .Ic \&St
1726 macro has an unknown argument and is discarded.
1727 .It Sy "skipping request without numeric argument"
1728 .Pq roff , eqn
1729 An
1730 .Ic \&it
1731 request or an
1732 .Xr eqn 7
1733 .Ic \&size
1734 or
1735 .Ic \&gsize
1736 statement has a non-numeric or negative argument or no argument at all.
1737 The invalid request or statement is ignored.
1738 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
1739 .Pq roff
1740 For security reasons,
1741 .Nm
1742 allows
1743 .Ic \&so
1744 file inclusion requests only with relative paths
1745 and only without ascending to any parent directory.
1746 By requesting the inclusion of a sensitive file, a malicious document
1747 might otherwise trick a privileged user into inadvertently displaying
1748 the file on the screen, revealing the file content to bystanders.
1749 .Nm
1750 only shows the path as it appears behind
1751 .Ic \&so .
1752 .It Sy ".so request failed"
1753 .Pq roff
1754 Servicing a
1755 .Ic \&so
1756 request requires reading an external file, but the file could not be
1757 opened.
1758 .Nm
1759 only shows the path as it appears behind
1760 .Ic \&so .
1761 .It Sy "skipping all arguments"
1762 .Pq mdoc , man , eqn , roff
1763 An
1764 .Xr mdoc 7
1765 .Ic \&Bt ,
1766 .Ic \&Ed ,
1767 .Ic \&Ef ,
1768 .Ic \&Ek ,
1769 .Ic \&El ,
1770 .Ic \&Lp ,
1771 .Ic \&Pp ,
1772 .Ic \&Re ,
1773 .Ic \&Rs ,
1774 or
1775 .Ic \&Ud
1776 macro, an
1777 .Ic \&It
1778 macro in a list that don't support item heads, a
1779 .Xr man 7
1780 .Ic \&LP ,
1781 .Ic \&P ,
1782 or
1783 .Ic \&PP
1784 macro, an
1785 .Xr eqn 7
1786 .Ic \&EQ
1787 or
1788 .Ic \&EN
1789 macro, or a
1790 .Xr roff 7
1791 .Ic \&br ,
1792 .Ic \&fi ,
1793 or
1794 .Ic \&nf
1795 request or
1796 .Sq \&..
1797 block closing request is invoked with at least one argument.
1798 All arguments are ignored.
1799 .It Sy "skipping excess arguments"
1800 .Pq mdoc , man , roff
1801 A macro or request is invoked with too many arguments:
1802 .Bl -dash -offset 2n -width 2n -compact
1803 .It
1804 .Ic \&Fo ,
1805 .Ic \&PD ,
1806 .Ic \&RS ,
1807 .Ic \&UR ,
1808 .Ic \&ft ,
1809 or
1810 .Ic \&sp
1811 with more than one argument
1812 .It
1813 .Ic \&An
1814 with another argument after
1815 .Fl split
1816 or
1817 .Fl nosplit
1818 .It
1819 .Ic \&RE
1820 with more than one argument or with a non-integer argument
1821 .It
1822 .Ic \&OP
1823 or a request of the
1824 .Ic \&de
1825 family with more than two arguments
1826 .It
1827 .Ic \&Dt
1828 with more than three arguments
1829 .It
1830 .Ic \&TH
1831 with more than five arguments
1832 .It
1833 .Ic \&Bd ,
1834 .Ic \&Bk ,
1835 or
1836 .Ic \&Bl
1837 with invalid arguments
1838 .El
1839 The excess arguments are ignored.
1840 .El
1841 .Ss Unsupported features
1842 .Bl -ohang
1843 .It Sy "input too large"
1844 .Pq mdoc , man
1845 Currently,
1846 .Nm
1847 cannot handle input files larger than its arbitrary size limit
1848 of 2^31 bytes (2 Gigabytes).
1849 Since useful manuals are always small, this is not a problem in practice.
1850 Parsing is aborted as soon as the condition is detected.
1851 .It Sy "unsupported control character"
1852 .Pq roff
1853 An ASCII control character supported by other
1854 .Xr roff 7
1855 implementations but not by
1856 .Nm
1857 was found in an input file.
1858 It is replaced by a question mark.
1859 .It Sy "unsupported roff request"
1860 .Pq roff
1861 An input file contains a
1862 .Xr roff 7
1863 request supported by GNU troff or Heirloom troff but not by
1864 .Nm ,
1865 and it is likely that this will cause information loss
1866 or considerable misformatting.
1867 .It Sy "eqn delim option in tbl"
1868 .Pq eqn , tbl
1869 The options line of a table defines equation delimiters.
1870 Any equation source code contained in the table will be printed unformatted.
1871 .It Sy "unsupported table layout modifier"
1872 .Pq tbl
1873 A table layout specification contains an
1874 .Sq Cm m
1875 modifier.
1876 The modifier is discarded.
1877 .It Sy "ignoring macro in table"
1878 .Pq tbl , mdoc , man
1879 A table contains an invocation of an
1880 .Xr mdoc 7
1881 or
1882 .Xr man 7
1883 macro or of an undefined macro.
1884 The macro is ignored, and its arguments are handled
1885 as if they were a text line.
1886 .El
1887 .Sh SEE ALSO
1888 .Xr apropos 1 ,
1889 .Xr man 1 ,
1890 .Xr eqn 7 ,
1891 .Xr man 7 ,
1892 .Xr mandoc_char 7 ,
1893 .Xr mdoc 7 ,
1894 .Xr roff 7 ,
1895 .Xr tbl 7
1896 .Sh HISTORY
1897 The
1898 .Nm
1899 utility first appeared in
1900 .Ox 4.8 .
1901 The option
1902 .Fl I
1903 appeared in
1904 .Ox 5.2 ,
1905 and
1906 .Fl aCcfhKklMSsw
1907 in
1908 .Ox 5.7 .
1909 .Sh AUTHORS
1910 .An -nosplit
1911 The
1912 .Nm
1913 utility was written by
1914 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1915 and is maintained by
1916 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .