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Radical cleanup of COMPATIBILITY sections:
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1 .\" $Id: mandoc.1,v 1.141 2015/01/29 00:33:57 schwarze Exp $
2 .\"
3 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4 .\" Copyright (c) 2012, 2014, 2015 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: January 29 2015 $
19 .Dt MANDOC 1
20 .Os
21 .Sh NAME
22 .Nm mandoc
23 .Nd format and display UNIX manuals
24 .Sh SYNOPSIS
25 .Nm mandoc
26 .Op Fl acfhklV
27 .Sm off
28 .Op Fl I Cm os Li = Ar name
29 .Sm on
30 .Op Fl K Ns Ar encoding
31 .Op Fl m Ns Ar format
32 .Op Fl O Ns Ar option
33 .Op Fl T Ns Ar output
34 .Op Fl W Ns Ar level
35 .Op Ar
36 .Sh DESCRIPTION
37 The
38 .Nm
39 utility formats
40 .Ux
41 manual pages for display.
42 .Pp
43 By default,
44 .Nm
45 reads
46 .Xr mdoc 7
47 or
48 .Xr man 7
49 text from stdin, implying
50 .Fl m Ns Cm andoc ,
51 and produces
52 .Fl T Ns Cm locale
53 output.
54 .Pp
55 The options are as follows:
56 .Bl -tag -width Ds
57 .It Fl a
58 If the standard output is a terminal device and
59 .Fl c
60 is not specified, use
61 .Xr more 1
62 to paginate the output, just like
63 .Xr man 1
64 would.
65 .It Fl c
66 Copy the formatted manual pages to the standard output without using
67 .Xr more 1
68 to paginate them.
69 This is the default.
70 It can be specified to override
71 .Fl a .
72 .It Fl f
73 A synonym for
74 .Xr whatis 1 .
75 This overrides any earlier
76 .Fl k
77 and
78 .Fl l
79 options.
80 .Sm off
81 .It Fl I Cm os Li = Ar name
82 .Sm on
83 Override the default operating system
84 .Ar name
85 for the
86 .Xr mdoc 7
87 .Sq \&Os
88 and for the
89 .Xr man 7
90 .Sq \&TH
91 macro.
92 .It Fl h
93 Display only the SYNOPSIS lines.
94 Implies
95 .Fl c .
96 .It Fl K Ns Ar encoding
97 Specify the input encoding.
98 The supported
99 .Ar encoding
100 arguments are
101 .Cm us-ascii ,
102 .Cm iso-8859-1 ,
103 and
104 .Cm utf-8 .
105 If not specified, autodetection uses the first match:
106 .Bl -tag -width iso-8859-1
107 .It Cm utf-8
108 if the first three bytes of the input file
109 are the UTF-8 byte order mark (BOM, 0xefbbbf)
110 .It Ar encoding
111 if the first or second line of the input file matches the
112 .Sy emacs
113 mode line format
114 .Pp
115 .D1 .\e" -*- Oo ...; Oc coding: Ar encoding ; No -*-
116 .It Cm utf-8
117 if the first non-ASCII byte in the file introduces a valid UTF-8 sequence
118 .It Cm iso-8859-1
119 otherwise
120 .El
121 .It Fl k
122 A synonym for
123 .Xr apropos 1 .
124 This overrides any earlier
125 .Fl f
126 and
127 .Fl l
128 options.
129 .It Fl l
130 A synonym for
131 .Fl a .
132 Also reverts any earlier
133 .Fl f
134 and
135 .Fl k
136 options.
137 .It Fl m Ns Ar format
138 Input format.
139 See
140 .Sx Input Formats
141 for available formats.
142 Defaults to
143 .Fl m Ns Cm andoc .
144 .It Fl O Ns Ar option
145 Comma-separated output options.
146 .It Fl T Ns Ar output
147 Output format.
148 See
149 .Sx Output Formats
150 for available formats.
151 Defaults to
152 .Fl T Ns Cm locale .
153 .It Fl V
154 Print version and exit.
155 .It Fl W Ns Ar level
156 Specify the minimum message
157 .Ar level
158 to be reported on the standard error output and to affect the exit status.
159 The
160 .Ar level
161 can be
162 .Cm warning ,
163 .Cm error ,
164 or
165 .Cm unsupp ;
166 .Cm all
167 is an alias for
168 .Cm warning .
169 By default,
170 .Nm
171 is silent.
172 See
173 .Sx EXIT STATUS
174 and
175 .Sx DIAGNOSTICS
176 for details.
177 .Pp
178 The special option
179 .Fl W Ns Cm stop
180 tells
181 .Nm
182 to exit after parsing a file that causes warnings or errors of at least
183 the requested level.
184 No formatted output will be produced from that file.
185 If both a
186 .Ar level
187 and
188 .Cm stop
189 are requested, they can be joined with a comma, for example
190 .Fl W Ns Cm error , Ns Cm stop .
191 .It Ar file
192 Read input from zero or more files.
193 If unspecified, reads from stdin.
194 If multiple files are specified,
195 .Nm
196 will halt with the first failed parse.
197 .El
198 .Pp
199 In
200 .Fl f
201 and
202 .Fl k
203 mode,
204 .Nm
205 also supports the options
206 .Fl CMmOSsw
207 described in the
208 .Xr apropos 1
209 manual.
210 .Ss Input Formats
211 The
212 .Nm
213 utility accepts
214 .Xr mdoc 7
215 and
216 .Xr man 7
217 input with
218 .Fl m Ns Cm doc
219 and
220 .Fl m Ns Cm an ,
221 respectively.
222 The
223 .Xr mdoc 7
224 format is
225 .Em strongly
226 recommended;
227 .Xr man 7
228 should only be used for legacy manuals.
229 .Pp
230 A third option,
231 .Fl m Ns Cm andoc ,
232 which is also the default, determines encoding on-the-fly: if the first
233 non-comment macro is
234 .Sq \&Dd
235 or
236 .Sq \&Dt ,
237 the
238 .Xr mdoc 7
239 parser is used; otherwise, the
240 .Xr man 7
241 parser is used.
242 .Pp
243 If multiple
244 files are specified with
245 .Fl m Ns Cm andoc ,
246 each has its file-type determined this way.
247 If multiple files are
248 specified and
249 .Fl m Ns Cm doc
250 or
251 .Fl m Ns Cm an
252 is specified, then this format is used exclusively.
253 .Ss Output Formats
254 The
255 .Nm
256 utility accepts the following
257 .Fl T
258 arguments, which correspond to output modes:
259 .Bl -tag -width "-Tlocale"
260 .It Fl T Ns Cm ascii
261 Produce 7-bit ASCII output.
262 See
263 .Sx ASCII Output .
264 .It Fl T Ns Cm html
265 Produce HTML5, CSS1, and MathML output.
266 See
267 .Sx HTML Output .
268 .It Fl T Ns Cm lint
269 Parse only: produce no output.
270 Implies
271 .Fl W Ns Cm warning .
272 .It Fl T Ns Cm locale
273 Encode output using the current locale.
274 This is the default.
275 See
276 .Sx Locale Output .
277 .It Fl T Ns Cm man
278 Produce
279 .Xr man 7
280 format output.
281 See
282 .Sx Man Output .
283 .It Fl T Ns Cm pdf
284 Produce PDF output.
285 See
286 .Sx PDF Output .
287 .It Fl T Ns Cm ps
288 Produce PostScript output.
289 See
290 .Sx PostScript Output .
291 .It Fl T Ns Cm tree
292 Produce an indented parse tree.
293 .It Fl T Ns Cm utf8
294 Encode output in the UTF\-8 multi-byte format.
295 See
296 .Sx UTF\-8 Output .
297 .It Fl T Ns Cm xhtml
298 This is a synonym for
299 .Fl T Ns Cm html .
300 .El
301 .Pp
302 If multiple input files are specified, these will be processed by the
303 corresponding filter in-order.
304 .Ss ASCII Output
305 Output produced by
306 .Fl T Ns Cm ascii
307 is rendered in standard 7-bit ASCII documented in
308 .Xr ascii 7 .
309 .Pp
310 Font styles are applied by using back-spaced encoding such that an
311 underlined character
312 .Sq c
313 is rendered as
314 .Sq _ Ns \e[bs] Ns c ,
315 where
316 .Sq \e[bs]
317 is the back-space character number 8.
318 Emboldened characters are rendered as
319 .Sq c Ns \e[bs] Ns c .
320 .Pp
321 The special characters documented in
322 .Xr mandoc_char 7
323 are rendered best-effort in an ASCII equivalent.
324 .Pp
325 Output width is limited to 78 visible columns unless literal input lines
326 exceed this limit.
327 .Pp
328 The following
329 .Fl O
330 arguments are accepted:
331 .Bl -tag -width Ds
332 .It Cm indent Ns = Ns Ar indent
333 The left margin for normal text is set to
334 .Ar indent
335 blank characters instead of the default of five for
336 .Xr mdoc 7
337 and seven for
338 .Xr man 7 .
339 Increasing this is not recommended; it may result in degraded formatting,
340 for example overfull lines or ugly line breaks.
341 .It Cm width Ns = Ns Ar width
342 The output width is set to
343 .Ar width ,
344 which will normalise to \(>=58.
345 .El
346 .Ss HTML Output
347 Output produced by
348 .Fl T Ns Cm html
349 conforms to HTML5 using optional self-closing tags.
350 Default styles use only CSS1.
351 Equations rendered from
352 .Xr eqn 7
353 blocks use MathML.
354 .Pp
355 The
356 .Pa example.style.css
357 file documents style-sheet classes available for customising output.
358 If a style-sheet is not specified with
359 .Fl O Ns Ar style ,
360 .Fl T Ns Cm html
361 defaults to simple output (via an embedded style-sheet)
362 readable in any graphical or text-based web
363 browser.
364 .Pp
365 Special characters are rendered in decimal-encoded UTF\-8.
366 .Pp
367 The following
368 .Fl O
369 arguments are accepted:
370 .Bl -tag -width Ds
371 .It Cm fragment
372 Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
373 elements and only emit the subtree below the <body> element.
374 The
375 .Cm style
376 argument will be ignored.
377 This is useful when embedding manual content within existing documents.
378 .It Cm includes Ns = Ns Ar fmt
379 The string
380 .Ar fmt ,
381 for example,
382 .Ar ../src/%I.html ,
383 is used as a template for linked header files (usually via the
384 .Sq \&In
385 macro).
386 Instances of
387 .Sq \&%I
388 are replaced with the include filename.
389 The default is not to present a
390 hyperlink.
391 .It Cm man Ns = Ns Ar fmt
392 The string
393 .Ar fmt ,
394 for example,
395 .Ar ../html%S/%N.%S.html ,
396 is used as a template for linked manuals (usually via the
397 .Sq \&Xr
398 macro).
399 Instances of
400 .Sq \&%N
401 and
402 .Sq %S
403 are replaced with the linked manual's name and section, respectively.
404 If no section is included, section 1 is assumed.
405 The default is not to
406 present a hyperlink.
407 .It Cm style Ns = Ns Ar style.css
408 The file
409 .Ar style.css
410 is used for an external style-sheet.
411 This must be a valid absolute or
412 relative URI.
413 .El
414 .Ss Locale Output
415 Locale-depending output encoding is triggered with
416 .Fl T Ns Cm locale .
417 This is the default.
418 .Pp
419 This option is not available on all systems: systems without locale
420 support, or those whose internal representation is not natively UCS-4,
421 will fall back to
422 .Fl T Ns Cm ascii .
423 See
424 .Sx ASCII Output
425 for font style specification and available command-line arguments.
426 .Ss Man Output
427 Translate input format into
428 .Xr man 7
429 output format.
430 This is useful for distributing manual sources to legacy systems
431 lacking
432 .Xr mdoc 7
433 formatters.
434 .Pp
435 If
436 .Xr mdoc 7
437 is passed as input, it is translated into
438 .Xr man 7 .
439 If the input format is
440 .Xr man 7 ,
441 the input is copied to the output, expanding any
442 .Xr roff 7
443 .Sq so
444 requests.
445 The parser is also run, and as usual, the
446 .Fl W
447 level controls which
448 .Sx DIAGNOSTICS
449 are displayed before copying the input to the output.
450 .Ss PDF Output
451 PDF-1.1 output may be generated by
452 .Fl T Ns Cm pdf .
453 See
454 .Sx PostScript Output
455 for
456 .Fl O
457 arguments and defaults.
458 .Ss PostScript Output
459 PostScript
460 .Qq Adobe-3.0
461 Level-2 pages may be generated by
462 .Fl T Ns Cm ps .
463 Output pages default to letter sized and are rendered in the Times font
464 family, 11-point.
465 Margins are calculated as 1/9 the page length and width.
466 Line-height is 1.4m.
467 .Pp
468 Special characters are rendered as in
469 .Sx ASCII Output .
470 .Pp
471 The following
472 .Fl O
473 arguments are accepted:
474 .Bl -tag -width Ds
475 .It Cm paper Ns = Ns Ar name
476 The paper size
477 .Ar name
478 may be one of
479 .Ar a3 ,
480 .Ar a4 ,
481 .Ar a5 ,
482 .Ar legal ,
483 or
484 .Ar letter .
485 You may also manually specify dimensions as
486 .Ar NNxNN ,
487 width by height in millimetres.
488 If an unknown value is encountered,
489 .Ar letter
490 is used.
491 .El
492 .Ss UTF\-8 Output
493 Use
494 .Fl T Ns Cm utf8
495 to force a UTF\-8 locale.
496 See
497 .Sx Locale Output
498 for details and options.
499 .Sh ENVIRONMENT
500 .Bl -tag -width MANPAGER
501 .It Ev MANPAGER
502 Any non-empty value of the environment variable
503 .Ev MANPAGER
504 will be used instead of the standard pagination program,
505 .Xr more 1 .
506 .It Ev PAGER
507 Specifies the pagination program to use when
508 .Ev MANPAGER
509 is not defined.
510 If neither PAGER nor MANPAGER is defined,
511 .Pa /usr/bin/more Fl s
512 will be used.
513 .El
514 .Sh EXIT STATUS
515 The
516 .Nm
517 utility exits with one of the following values, controlled by the message
518 .Ar level
519 associated with the
520 .Fl W
521 option:
522 .Pp
523 .Bl -tag -width Ds -compact
524 .It 0
525 No warnings or errors occurred, or those that did were ignored because
526 they were lower than the requested
527 .Ar level .
528 .It 2
529 At least one warning occurred, but no error, and
530 .Fl W Ns Cm warning
531 was specified.
532 .It 3
533 At least one parsing error occurred,
534 but no unsupported feature was encountered, and
535 .Fl W Ns Cm error
536 or
537 .Fl W Ns Cm warning
538 was specified.
539 .It 4
540 At least one unsupported feature was encountered, and
541 .Fl W Ns Cm unsupp ,
542 .Fl W Ns Cm error
543 or
544 .Fl W Ns Cm warning
545 was specified.
546 .It 5
547 Invalid command line arguments were specified.
548 No input files have been read.
549 .It 6
550 An operating system error occurred, for example exhaustion
551 of memory, file descriptors, or process table entries.
552 Such errors cause
553 .Nm
554 to exit at once, possibly in the middle of parsing or formatting a file.
555 .El
556 .Pp
557 Note that selecting
558 .Fl T Ns Cm lint
559 output mode implies
560 .Fl W Ns Cm warning .
561 .Sh EXAMPLES
562 To page manuals to the terminal:
563 .Pp
564 .Dl $ mandoc \-Wall,stop mandoc.1 2\*(Gt&1 | less
565 .Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
566 .Pp
567 To produce HTML manuals with
568 .Ar style.css
569 as the style-sheet:
570 .Pp
571 .Dl $ mandoc \-Thtml -Ostyle=style.css mdoc.7 \*(Gt mdoc.7.html
572 .Pp
573 To check over a large set of manuals:
574 .Pp
575 .Dl $ mandoc \-Tlint `find /usr/src -name \e*\e.[1-9]`
576 .Pp
577 To produce a series of PostScript manuals for A4 paper:
578 .Pp
579 .Dl $ mandoc \-Tps \-Opaper=a4 mdoc.7 man.7 \*(Gt manuals.ps
580 .Pp
581 Convert a modern
582 .Xr mdoc 7
583 manual to the older
584 .Xr man 7
585 format, for use on systems lacking an
586 .Xr mdoc 7
587 parser:
588 .Pp
589 .Dl $ mandoc \-Tman foo.mdoc \*(Gt foo.man
590 .Sh DIAGNOSTICS
591 Messages displayed by
592 .Nm
593 follow this format:
594 .Pp
595 .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
596 .Pp
597 Line and column numbers start at 1.
598 Both are omitted for messages referring to an input file as a whole.
599 Macro names and arguments are omitted where meaningless.
600 Fatal messages about invalid command line arguments
601 or operating system errors, for example when memory is exhausted,
602 may also omit the
603 .Ar file
604 and
605 .Ar level
606 fields.
607 .Pp
608 Message levels have the following meanings:
609 .Bl -tag -width "warning"
610 .It Cm unsupp
611 An input file uses unsupported low-level
612 .Xr roff 7
613 features.
614 The output may be incomplete and/or misformatted,
615 so using GNU troff instead of
616 .Nm
617 to process the file may be preferable.
618 .It Cm error
619 An input file contains invalid syntax that cannot be safely interpreted.
620 By discarding part of the input or inserting missing tokens,
621 the parser is able to continue, and the error does not prevent
622 generation of formatted output, but typically, preparing that
623 output involves information loss, broken document structure
624 or unintended formatting, no matter whether
625 .Nm
626 or GNU troff is used.
627 In many cases, the output of
628 .Nm
629 and GNU troff is identical, but in some,
630 .Nm
631 is more resilient than GNU troff with respect to malformed input.
632 .Pp
633 Non-existent or unreadable input files are also reported on the
634 .Cm error
635 level.
636 In that case, the parser cannot even be started and no output
637 is produced from those input files.
638 .It Cm warning
639 An input file uses obsolete, discouraged or non-portable syntax.
640 All the same, the meaning of the input is unambiguous and a correct
641 rendering can be produced.
642 Documents causing warnings may render poorly when using other
643 formatting tools instead of
644 .Nm .
645 .El
646 .Pp
647 Messages of the
648 .Cm warning ,
649 .Cm error ,
650 and
651 .Cm unsupp
652 levels except those about non-existent or unreadable input files
653 are hidden unless their level, or a lower level, is requested using a
654 .Fl W
655 option or
656 .Fl T Ns Cm lint
657 output mode.
658 .Ss Warnings related to the document prologue
659 .Bl -ohang
660 .It Sy "missing manual title, using UNTITLED"
661 .Pq mdoc
662 A
663 .Ic \&Dt
664 macro has no arguments, or there is no
665 .Ic \&Dt
666 macro before the first non-prologue macro.
667 .It Sy "missing manual title, using \(dq\(dq"
668 .Pq man
669 There is no
670 .Ic \&TH
671 macro, or it has no arguments.
672 .It Sy "lower case character in document title"
673 .Pq mdoc , man
674 The title is still used as given in the
675 .Ic \&Dt
676 or
677 .Ic \&TH
678 macro.
679 .It Sy "missing manual section, using \(dq\(dq"
680 .Pq mdoc , man
681 A
682 .Ic \&Dt
683 or
684 .Ic \&TH
685 macro lacks the mandatory section argument.
686 .It Sy "unknown manual section"
687 .Pq mdoc
688 The section number in a
689 .Ic \&Dt
690 line is invalid, but still used.
691 .It Sy "missing date, using today's date"
692 .Pq mdoc, man
693 The document was parsed as
694 .Xr mdoc 7
695 and it has no
696 .Ic \&Dd
697 macro, or the
698 .Ic \&Dd
699 macro has no arguments or only empty arguments;
700 or the document was parsed as
701 .Xr man 7
702 and it has no
703 .Ic \&TH
704 macro, or the
705 .Ic \&TH
706 macro has less than three arguments or its third argument is empty.
707 .It Sy "cannot parse date, using it verbatim"
708 .Pq mdoc , man
709 The date given in a
710 .Ic \&Dd
711 or
712 .Ic \&TH
713 macro does not follow the conventional format.
714 .It Sy "missing Os macro, using \(dq\(dq"
715 .Pq mdoc
716 The default or current system is not shown in this case.
717 .It Sy "duplicate prologue macro"
718 .Pq mdoc
719 One of the prologue macros occurs more than once.
720 The last instance overrides all previous ones.
721 .It Sy "late prologue macro"
722 .Pq mdoc
723 A
724 .Ic \&Dd
725 or
726 .Ic \&Os
727 macro occurs after some non-prologue macro, but still takes effect.
728 .It Sy "skipping late title macro"
729 .Pq mdoc
730 The
731 .Ic \&Dt
732 macro can only occur before the first non-prologue macro
733 because traditional formatters write the page header
734 before parsing the document body.
735 Even though this technical restriction does not apply to
736 .Nm ,
737 traditional semantics is preserved.
738 The late macro is discarded including its arguments.
739 .It Sy "prologue macros out of order"
740 .Pq mdoc
741 The prologue macros are not given in the conventional order
742 .Ic \&Dd ,
743 .Ic \&Dt ,
744 .Ic \&Os .
745 All three macros are used even when given in another order.
746 .El
747 .Ss Warnings regarding document structure
748 .Bl -ohang
749 .It Sy ".so is fragile, better use ln(1)"
750 .Pq roff
751 Including files only works when the parser program runs with the correct
752 current working directory.
753 .It Sy "no document body"
754 .Pq mdoc , man
755 The document body contains neither text nor macros.
756 An empty document is shown, consisting only of a header and a footer line.
757 .It Sy "content before first section header"
758 .Pq mdoc , man
759 Some macros or text precede the first
760 .Ic \&Sh
761 or
762 .Ic \&SH
763 section header.
764 The offending macros and text are parsed and added to the top level
765 of the syntax tree, outside any section block.
766 .It Sy "first section is not NAME"
767 .Pq mdoc
768 The argument of the first
769 .Ic \&Sh
770 macro is not
771 .Sq NAME .
772 This may confuse
773 .Xr makewhatis 8
774 and
775 .Xr apropos 1 .
776 .It Sy "bad NAME section contents"
777 .Pq mdoc
778 The last node in the NAME section is not an
779 .Ic \&Nd
780 macro, or any preceding macro is not
781 .Ic \&Nm ,
782 or the NAME section is completely empty.
783 This may confuse
784 .Xr makewhatis 8
785 and
786 .Xr apropos 1 .
787 .It Sy "sections out of conventional order"
788 .Pq mdoc
789 A standard section occurs after another section it usually precedes.
790 All section titles are used as given,
791 and the order of sections is not changed.
792 .It Sy "duplicate section title"
793 .Pq mdoc
794 The same standard section title occurs more than once.
795 .It Sy "unexpected section"
796 .Pq mdoc
797 A standard section header occurs in a section of the manual
798 where it normally isn't useful.
799 .It Sy "unusual Xr order"
800 .Pq mdoc
801 In the SEE ALSO section, an
802 .Ic \&Xr
803 macro with a lower section number follows one with a higher number,
804 or two
805 .Ic \&Xr
806 macros refering to the same section are out of alphabetical order.
807 .It Sy "unusual Xr punctuation"
808 .Pq mdoc
809 In the SEE ALSO section, punctuation between two
810 .Ic \&Xr
811 macros differs from a single comma, or there is trailing punctuation
812 after the last
813 .Ic \&Xr
814 macro.
815 .It Sy "AUTHORS section without An macro"
816 .Pq mdoc
817 An AUTHORS sections contains no
818 .Ic \&An
819 macros, or only empty ones.
820 Probably, there are author names lacking markup.
821 .El
822 .Ss "Warnings related to macros and nesting"
823 .Bl -ohang
824 .It Sy "obsolete macro"
825 .Pq mdoc
826 See the
827 .Xr mdoc 7
828 manual for replacements.
829 .It Sy "macro neither callable nor escaped"
830 .Pq mdoc
831 The name of a macro that is not callable appears on a macro line.
832 It is printed verbatim.
833 If the intention is to call it, move it to its own line;
834 otherwise, escape it by prepending
835 .Sq \e& .
836 .It Sy "skipping paragraph macro"
837 In
838 .Xr mdoc 7
839 documents, this happens
840 .Bl -dash -compact
841 .It
842 at the beginning and end of sections and subsections
843 .It
844 right before non-compact lists and displays
845 .It
846 at the end of items in non-column, non-compact lists
847 .It
848 and for multiple consecutive paragraph macros.
849 .El
850 In
851 .Xr man 7
852 documents, it happens
853 .Bl -dash -compact
854 .It
855 for empty
856 .Ic \&P ,
857 .Ic \&PP ,
858 and
859 .Ic \&LP
860 macros
861 .It
862 for
863 .Ic \&IP
864 macros having neither head nor body arguments
865 .It
866 for
867 .Ic \&br
868 or
869 .Ic \&sp
870 right after
871 .Ic \&SH
872 or
873 .Ic \&SS
874 .El
875 .It Sy "moving paragraph macro out of list"
876 .Pq mdoc
877 A list item in a
878 .Ic \&Bl
879 list contains a trailing paragraph macro.
880 The paragraph macro is moved after the end of the list.
881 .It Sy "skipping no-space macro"
882 .Pq mdoc
883 An input line begins with an
884 .Ic \&Ns
885 macro.
886 The macro is ignored.
887 .It Sy "blocks badly nested"
888 .Pq mdoc
889 If two blocks intersect, one should completely contain the other.
890 Otherwise, rendered output is likely to look strange in any output
891 format, and rendering in SGML-based output formats is likely to be
892 outright wrong because such languages do not support badly nested
893 blocks at all.
894 Typical examples of badly nested blocks are
895 .Qq Ic \&Ao \&Bo \&Ac \&Bc
896 and
897 .Qq Ic \&Ao \&Bq \&Ac .
898 In these examples,
899 .Ic \&Ac
900 breaks
901 .Ic \&Bo
902 and
903 .Ic \&Bq ,
904 respectively.
905 .It Sy "nested displays are not portable"
906 .Pq mdoc
907 A
908 .Ic \&Bd ,
909 .Ic \&D1 ,
910 or
911 .Ic \&Dl
912 display occurs nested inside another
913 .Ic \&Bd
914 display.
915 This works with
916 .Nm ,
917 but fails with most other implementations.
918 .It Sy "moving content out of list"
919 .Pq mdoc
920 A
921 .Ic \&Bl
922 list block contains text or macros before the first
923 .Ic \&It
924 macro.
925 The offending children are moved before the beginning of the list.
926 .It Sy ".Vt block has child macro"
927 .Pq mdoc
928 The
929 .Ic \&Vt
930 macro supports plain text arguments only.
931 Formatting may be ugly and semantic searching
932 for the affected content might not work.
933 .It Sy "fill mode already enabled, skipping"
934 .Pq man
935 A
936 .Ic \&fi
937 request occurs even though the document is still in fill mode,
938 or already switched back to fill mode.
939 It has no effect.
940 .It Sy "fill mode already disabled, skipping"
941 .Pq man
942 An
943 .Ic \&nf
944 request occurs even though the document already switched to no-fill mode
945 and did not switch back to fill mode yet.
946 It has no effect.
947 .It Sy "line scope broken"
948 .Pq man
949 While parsing the next-line scope of the previous macro,
950 another macro is found that prematurely terminates the previous one.
951 The previous, interrupted macro is deleted from the parse tree.
952 .El
953 .Ss "Warnings related to missing arguments"
954 .Bl -ohang
955 .It Sy "skipping empty request"
956 .Pq roff , eqn
957 The macro name is missing from a macro definition request,
958 or an
959 .Xr eqn 7
960 control statement or operation keyword lacks its required argument.
961 .It Sy "conditional request controls empty scope"
962 .Pq roff
963 A conditional request is only useful if any of the following
964 follows it on the same logical input line:
965 .Bl -dash -compact
966 .It
967 The
968 .Sq \e{
969 keyword to open a multi-line scope.
970 .It
971 A request or macro or some text, resulting in a single-line scope.
972 .It
973 The immediate end of the logical line without any intervening whitespace,
974 resulting in next-line scope.
975 .El
976 Here, a conditional request is followed by trailing whitespace only,
977 and there is no other content on its logical input line.
978 Note that it doesn't matter whether the logical input line is split
979 across multiple physical input lines using
980 .Sq \e
981 line continuation characters.
982 This is one of the rare cases
983 where trailing whitespace is syntactically significant.
984 The conditional request controls a scope containing whitespace only,
985 so it is unlikely to have a significant effect,
986 except that it may control a following
987 .Ic \&el
988 clause.
989 .It Sy "skipping empty macro"
990 .Pq mdoc
991 The indicated macro has no arguments and hence no effect.
992 .It Sy "empty argument, using 0n"
993 .Pq mdoc
994 The required width is missing after
995 .Ic \&Bd
996 or
997 .Ic \&Bl
998 .Fl offset
999 or
1000 .Fl width.
1001 .It Sy "argument count wrong"
1002 .Pq mdoc , man
1003 The indicated macro has too few or too many arguments.
1004 The syntax tree will contain the wrong number of arguments as given.
1005 Formatting behaviour depends on the specific macro in question.
1006 Note that the same message may also occur as an ERROR, see below.
1007 .It Sy "missing display type, using -ragged"
1008 .Pq mdoc
1009 The
1010 .Ic \&Bd
1011 macro is invoked without the required display type.
1012 .It Sy "list type is not the first argument"
1013 .Pq mdoc
1014 In a
1015 .Ic \&Bl
1016 macro, at least one other argument precedes the type argument.
1017 The
1018 .Nm
1019 utility copes with any argument order, but some other
1020 .Xr mdoc 7
1021 implementations do not.
1022 .It Sy "missing -width in -tag list, using 8n"
1023 .Pq mdoc
1024 Every
1025 .Ic \&Bl
1026 macro having the
1027 .Fl tag
1028 argument requires
1029 .Fl width ,
1030 too.
1031 .It Sy "missing utility name, using \(dq\(dq"
1032 .Pq mdoc
1033 The
1034 .Ic \&Ex Fl std
1035 macro is called without an argument before
1036 .Ic \&Nm
1037 has first been called with an argument.
1038 .It Sy "empty head in list item"
1039 .Pq mdoc
1040 In a
1041 .Ic \&Bl
1042 .Fl diag ,
1043 .Fl hang ,
1044 .Fl inset ,
1045 .Fl ohang ,
1046 or
1047 .Fl tag
1048 list, an
1049 .Ic \&It
1050 macro lacks the required argument.
1051 The item head is left empty.
1052 .It Sy "empty list item"
1053 .Pq mdoc
1054 In a
1055 .Ic \&Bl
1056 .Fl bullet ,
1057 .Fl dash ,
1058 .Fl enum ,
1059 or
1060 .Fl hyphen
1061 list, an
1062 .Ic \&It
1063 block is empty.
1064 An empty list item is shown.
1065 .It Sy "missing font type"
1066 .Pq mdoc
1067 A
1068 .Ic \&Bf
1069 macro has no argument.
1070 It switches to the default font,
1071 .Cm \efR .
1072 .It Sy "unknown font type"
1073 .Pq mdoc
1074 The
1075 .Ic \&Bf
1076 argument is invalid.
1077 The default font
1078 .Cm \efR
1079 is used instead.
1080 .It Sy "nothing follows prefix"
1081 .Pq mdoc
1082 A
1083 .Ic \&Pf
1084 macro has no argument, or only one argument and no macro follows
1085 on the same input line.
1086 This defeats its purpose; in particular, spacing is not suppressed
1087 before the text or macros following on the next input line.
1088 .It Sy "missing -std argument, adding it"
1089 .Pq mdoc
1090 An
1091 .Ic \&Ex
1092 or
1093 .Ic \&Rv
1094 macro lacks the required
1095 .Fl std
1096 argument.
1097 The
1098 .Nm
1099 utility assumes
1100 .Fl std
1101 even when it is not specified, but other implementations may not.
1102 .It Sy "missing eqn box, using \(dq\(dq"
1103 .Pq eqn
1104 A diacritic mark or a binary operator is found,
1105 but there is nothing to the left of it.
1106 An empty box is inserted.
1107 .El
1108 .Ss "Warnings related to bad macro arguments"
1109 .Bl -ohang
1110 .It Sy "unterminated quoted argument"
1111 .Pq roff
1112 Macro arguments can be enclosed in double quote characters
1113 such that space characters and macro names contained in the quoted
1114 argument need not be escaped.
1115 The closing quote of the last argument of a macro can be omitted.
1116 However, omitting it is not recommended because it makes the code
1117 harder to read.
1118 .It Sy "duplicate argument"
1119 .Pq mdoc
1120 A
1121 .Ic \&Bd
1122 or
1123 .Ic \&Bl
1124 macro has more than one
1125 .Fl compact ,
1126 more than one
1127 .Fl offset ,
1128 or more than one
1129 .Fl width
1130 argument.
1131 All but the last instances of these arguments are ignored.
1132 .It Sy "skipping duplicate argument"
1133 .Pq mdoc
1134 An
1135 .Ic \&An
1136 macro has more than one
1137 .Fl split
1138 or
1139 .Fl nosplit
1140 argument.
1141 All but the first of these arguments are ignored.
1142 .It Sy "skipping duplicate display type"
1143 .Pq mdoc
1144 A
1145 .Ic \&Bd
1146 macro has more than one type argument; the first one is used.
1147 .It Sy "skipping duplicate list type"
1148 .Pq mdoc
1149 A
1150 .Ic \&Bl
1151 macro has more than one type argument; the first one is used.
1152 .It Sy "skipping -width argument"
1153 .Pq mdoc
1154 A
1155 .Ic \&Bl
1156 .Fl column ,
1157 .Fl diag ,
1158 .Fl ohang ,
1159 .Fl inset ,
1160 or
1161 .Fl item
1162 list has a
1163 .Fl width
1164 argument.
1165 That has no effect.
1166 .It Sy "unknown AT&T UNIX version"
1167 .Pq mdoc
1168 An
1169 .Ic \&At
1170 macro has an invalid argument.
1171 It is used verbatim, with
1172 .Qq "AT&T UNIX "
1173 prefixed to it.
1174 .It Sy "comma in function argument"
1175 .Pq mdoc
1176 An argument of an
1177 .Ic \&Fa
1178 or
1179 .Ic \&Fn
1180 macro contains a comma; it should probably be split into two arguments.
1181 .It Sy "parenthesis in function name"
1182 .Pq mdoc
1183 The first argument of an
1184 .Ic \&Fc
1185 or
1186 .Ic \&Fn
1187 macro contains an opening or closing parenthesis; that's probably wrong,
1188 parentheses are added automatically.
1189 .It Sy "invalid content in Rs block"
1190 .Pq mdoc
1191 An
1192 .Ic \&Rs
1193 block contains plain text or non-% macros.
1194 The bogus content is left in the syntax tree.
1195 Formatting may be poor.
1196 .It Sy "invalid Boolean argument"
1197 .Pq mdoc
1198 An
1199 .Ic \&Sm
1200 macro has an argument other than
1201 .Cm on
1202 or
1203 .Cm off .
1204 The invalid argument is moved out of the macro, which leaves the macro
1205 empty, causing it to toggle the spacing mode.
1206 .It Sy "unknown font, skipping request"
1207 .Pq man , tbl
1208 A
1209 .Xr roff 7
1210 .Ic \&ft
1211 request or a
1212 .Xr tbl 7
1213 .Ic \&f
1214 layout modifier has an unknown
1215 .Ar font
1216 argument.
1217 .El
1218 .Ss "Warnings related to plain text"
1219 .Bl -ohang
1220 .It Sy "blank line in fill mode, using .sp"
1221 .Pq mdoc
1222 The meaning of blank input lines is only well-defined in non-fill mode:
1223 In fill mode, line breaks of text input lines are not supposed to be
1224 significant.
1225 However, for compatibility with groff, blank lines in fill mode
1226 are replaced with
1227 .Ic \&sp
1228 requests.
1229 .It Sy "tab in filled text"
1230 .Pq mdoc , man
1231 The meaning of tab characters is only well-defined in non-fill mode:
1232 In fill mode, whitespace is not supposed to be significant
1233 on text input lines.
1234 As an implementation dependent choice, tab characters on text lines
1235 are passed through to the formatters in any case.
1236 Given that the text before the tab character will be filled,
1237 it is hard to predict which tab stop position the tab will advance to.
1238 .It Sy "whitespace at end of input line"
1239 .Pq mdoc , man , roff
1240 Whitespace at the end of input lines is almost never semantically
1241 significant \(em but in the odd case where it might be, it is
1242 extremely confusing when reviewing and maintaining documents.
1243 .It Sy "bad comment style"
1244 .Pq roff
1245 Comment lines start with a dot, a backslash, and a double-quote character.
1246 The
1247 .Nm
1248 utility treats the line as a comment line even without the backslash,
1249 but leaving out the backslash might not be portable.
1250 .It Sy "invalid escape sequence"
1251 .Pq roff
1252 An escape sequence has an invalid opening argument delimiter, lacks the
1253 closing argument delimiter, or the argument has too few characters.
1254 If the argument is incomplete,
1255 .Ic \e*
1256 and
1257 .Ic \en
1258 expand to an empty string,
1259 .Ic \eB
1260 to the digit
1261 .Sq 0 ,
1262 and
1263 .Ic \ew
1264 to the length of the incomplete argument.
1265 All other invalid escape sequences are ignored.
1266 .It Sy "undefined string, using \(dq\(dq"
1267 .Pq roff
1268 If a string is used without being defined before,
1269 its value is implicitly set to the empty string.
1270 However, defining strings explicitly before use
1271 keeps the code more readable.
1272 .El
1273 .Ss "Warnings related to tables"
1274 .Bl -ohang
1275 .It Sy "tbl line starts with span"
1276 .Pq tbl
1277 The first cell in a table layout line is a horizontal span
1278 .Pq Sq Cm s .
1279 Data provided for this cell is ignored, and nothing is printed in the cell.
1280 .It Sy "tbl column starts with span"
1281 .Pq tbl
1282 The first line of a table layout specification
1283 requests a vertical span
1284 .Pq Sq Cm ^ .
1285 Data provided for this cell is ignored, and nothing is printed in the cell.
1286 .It Sy "skipping vertical bar in tbl layout"
1287 .Pq tbl
1288 A table layout specification contains more than two consecutive vertical bars.
1289 A double bar is printed, all additional bars are discarded.
1290 .El
1291 .Ss "Errors related to tables"
1292 .Bl -ohang
1293 .It Sy "non-alphabetic character in tbl options"
1294 .Pq tbl
1295 The table options line contains a character other than a letter,
1296 blank, or comma where the beginning of an option name is expected.
1297 The character is ignored.
1298 .It Sy "skipping unknown tbl option"
1299 .Pq tbl
1300 The table options line contains a string of letters that does not
1301 match any known option name.
1302 The word is ignored.
1303 .It Sy "missing tbl option argument"
1304 .Pq tbl
1305 A table option that requires an argument is not followed by an
1306 opening parenthesis, or the opening parenthesis is immediately
1307 followed by a closing parenthesis.
1308 The option is ignored.
1309 .It Sy "wrong tbl option argument size"
1310 .Pq tbl
1311 A table option argument contains an invalid number of characters.
1312 Both the option and the argument are ignored.
1313 .It Sy "empty tbl layout"
1314 .Pq tbl
1315 A table layout specification is completely empty,
1316 specifying zero lines and zero columns.
1317 As a fallback, a single left-justified column is used.
1318 .It Sy "invalid character in tbl layout"
1319 .Pq tbl
1320 A table layout specification contains a character that can neither
1321 be interpreted as a layout key character nor as a layout modifier,
1322 or a modifier precedes the first key.
1323 The invalid character is discarded.
1324 .It Sy "unmatched parenthesis in tbl layout"
1325 .Pq tbl
1326 A table layout specification contains an opening parenthesis,
1327 but no matching closing parenthesis.
1328 The rest of the input line, starting from the parenthesis, has no effect.
1329 .It Sy "tbl without any data cells"
1330 .Pq tbl
1331 A table does not contain any data cells.
1332 It will probably produce no output.
1333 .It Sy "ignoring data in spanned tbl cell"
1334 .Pq tbl
1335 A table cell is marked as a horizontal span
1336 .Pq Sq Cm s
1337 or vertical span
1338 .Pq Sq Cm ^
1339 in the table layout, but it contains data.
1340 The data is ignored.
1341 .It Sy "ignoring extra tbl data cells"
1342 .Pq tbl
1343 A data line contains more cells than the corresponding layout line.
1344 The data in the extra cells is ignored.
1345 .It Sy "data block open at end of tbl"
1346 .Pq tbl
1347 A data block is opened with
1348 .Cm T{ ,
1349 but never closed with a matching
1350 .Cm T} .
1351 The remaining data lines of the table are all put into one cell,
1352 and any remaining cells stay empty.
1353 .El
1354 .Ss "Errors related to roff, mdoc, and man code"
1355 .Bl -ohang
1356 .It Sy "input stack limit exceeded, infinite loop?"
1357 .Pq roff
1358 Explicit recursion limits are implemented for the following features,
1359 in order to prevent infinite loops:
1360 .Bl -dash -compact
1361 .It
1362 expansion of nested escape sequences
1363 including expansion of strings and number registers,
1364 .It
1365 expansion of nested user-defined macros,
1366 .It
1367 and
1368 .Ic \&so
1369 file inclusion.
1370 .El
1371 When a limit is hit, the output is incorrect, typically losing
1372 some content, but the parser can continue.
1373 .It Sy "skipping bad character"
1374 .Pq mdoc , man , roff
1375 The input file contains a byte that is not a printable
1376 .Xr ascii 7
1377 character.
1378 The message mentions the character number.
1379 The offending byte is replaced with a question mark
1380 .Pq Sq \&? .
1381 Consider editing the input file to replace the byte with an ASCII
1382 transliteration of the intended character.
1383 .It Sy "skipping unknown macro"
1384 .Pq mdoc , man , roff
1385 The first identifier on a request or macro line is neither recognized as a
1386 .Xr roff 7
1387 request, nor as a user-defined macro, nor, respectively, as an
1388 .Xr mdoc 7
1389 or
1390 .Xr man 7
1391 macro.
1392 It may be mistyped or unsupported.
1393 The request or macro is discarded including its arguments.
1394 .It Sy "skipping insecure request"
1395 .Pq roff
1396 An input file attempted to run a shell command
1397 or to read or write an external file.
1398 Such attempts are denied for security reasons.
1399 .It Sy "skipping item outside list"
1400 .Pq mdoc , eqn
1401 An
1402 .Ic \&It
1403 macro occurs outside any
1404 .Ic \&Bl
1405 list, or an
1406 .Xr eqn 7
1407 .Ic above
1408 delimiter occurs outside any pile.
1409 It is discarded including its arguments.
1410 .It Sy "skipping column outside column list"
1411 .Pq mdoc
1412 A
1413 .Ic \&Ta
1414 macro occurs outside any
1415 .Ic \&Bl Fl column
1416 block.
1417 It is discarded including its arguments.
1418 .It Sy "skipping end of block that is not open"
1419 .Pq mdoc , man , eqn , tbl , roff
1420 Various syntax elements can only be used to explicitly close blocks
1421 that have previously been opened.
1422 An
1423 .Xr mdoc 7
1424 block closing macro, a
1425 .Xr man 7
1426 .Ic \&RE
1427 or
1428 .Ic \&UE
1429 macro, an
1430 .Xr eqn 7
1431 right delimiter or closing brace, or the end of an equation, table, or
1432 .Xr roff 7
1433 conditional request is encountered but no matching block is open.
1434 The offending request or macro is discarded.
1435 .It Sy "fewer RS blocks open, skipping"
1436 .Pq man
1437 The
1438 .Ic \&RE
1439 macro is invoked with an argument, but less than the specified number of
1440 .Ic \&RS
1441 blocks is open.
1442 The
1443 .Ic \&RE
1444 macro is discarded.
1445 .It Sy "inserting missing end of block"
1446 .Pq mdoc , tbl
1447 Various
1448 .Xr mdoc 7
1449 macros as well as tables require explicit closing by dedicated macros.
1450 A block that doesn't support bad nesting
1451 ends before all of its children are properly closed.
1452 The open child nodes are closed implicitly.
1453 .It Sy "scope open on exit"
1454 .Pq mdoc , man , eqn , tbl , roff
1455 At the end of the document, an explicit
1456 .Xr mdoc 7
1457 block, a
1458 .Xr man 7
1459 next-line scope or
1460 .Ic \&RS
1461 or
1462 .Ic \&UR
1463 block, an equation, table, or
1464 .Xr roff 7
1465 conditional or ignore block is still open.
1466 The open block is closed implicitly.
1467 .It Sy "escaped character not allowed in a name"
1468 .Pq roff
1469 Macro, string and register identifiers consist of printable,
1470 non-whitespace ASCII characters.
1471 Escape sequences and characters and strings expressed in terms of them
1472 cannot form part of a name.
1473 The first argument of an
1474 .Ic \&am ,
1475 .Ic \&as ,
1476 .Ic \&de ,
1477 .Ic \&ds ,
1478 .Ic \&nr ,
1479 or
1480 .Ic \&rr
1481 request, or any argument of an
1482 .Ic \&rm
1483 request, or the name of a request or user defined macro being called,
1484 is terminated by an escape sequence.
1485 In the cases of
1486 .Ic \&as ,
1487 .Ic \&ds ,
1488 and
1489 .Ic \&nr ,
1490 the request has no effect at all.
1491 In the cases of
1492 .Ic \&am ,
1493 .Ic \&de ,
1494 .Ic \&rr ,
1495 and
1496 .Ic \&rm ,
1497 what was parsed up to this point is used as the arguments to the request,
1498 and the rest of the input line is discarded including the escape sequence.
1499 When parsing for a request or a user-defined macro name to be called,
1500 only the escape sequence is discarded.
1501 The characters preceding it are used as the request or macro name,
1502 the characters following it are used as the arguments to the request or macro.
1503 .It Sy "argument count wrong"
1504 .Pq mdoc , man , roff
1505 The indicated request or macro has too few or too many arguments.
1506 The syntax tree will contain the wrong number of arguments as given.
1507 Formatting behaviour depends on the specific request or macro in question.
1508 Note that the same message may also occur as a WARNING, see above.
1509 .It Sy "NOT IMPLEMENTED: Bd -file"
1510 .Pq mdoc
1511 For security reasons, the
1512 .Ic \&Bd
1513 macro does not support the
1514 .Fl file
1515 argument.
1516 By requesting the inclusion of a sensitive file, a malicious document
1517 might otherwise trick a privileged user into inadvertently displaying
1518 the file on the screen, revealing the file content to bystanders.
1519 The argument is ignored including the file name following it.
1520 .It Sy "missing list type, using -item"
1521 .Pq mdoc
1522 A
1523 .Ic \&Bl
1524 macro fails to specify the list type.
1525 .It Sy "missing manual name, using \(dq\(dq"
1526 .Pq mdoc
1527 The first call to
1528 .Ic \&Nm
1529 lacks the required argument.
1530 .It Sy "uname(3) system call failed, using UNKNOWN"
1531 .Pq mdoc
1532 The
1533 .Ic \&Os
1534 macro is called without arguments, and the
1535 .Xr uname 3
1536 system call failed.
1537 As a workaround,
1538 .Nm
1539 can be compiled with
1540 .Sm off
1541 .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
1542 .Sm on
1543 .It Sy "unknown standard specifier"
1544 .Pq mdoc
1545 An
1546 .Ic \&St
1547 macro has an unknown argument and is discarded.
1548 .It Sy "skipping request without numeric argument"
1549 .Pq roff , eqn
1550 An
1551 .Ic \&it
1552 request or an
1553 .Xr eqn 7
1554 .Ic \&size
1555 or
1556 .Ic \&gsize
1557 statement has a non-numeric or negative argument or no argument at all.
1558 The invalid request or statement is ignored.
1559 .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
1560 .Pq roff
1561 For security reasons,
1562 .Nm
1563 allows
1564 .Ic \&so
1565 file inclusion requests only with relative paths
1566 and only without ascending to any parent directory.
1567 By requesting the inclusion of a sensitive file, a malicious document
1568 might otherwise trick a privileged user into inadvertently displaying
1569 the file on the screen, revealing the file content to bystanders.
1570 .Nm
1571 only shows the path as it appears behind
1572 .Ic \&so .
1573 .It Sy ".so request failed"
1574 .Pq roff
1575 Servicing a
1576 .Ic \&so
1577 request requires reading an external file, but the file could not be
1578 opened.
1579 .Nm
1580 only shows the path as it appears behind
1581 .Ic \&so .
1582 .It Sy "skipping all arguments"
1583 .Pq mdoc , man , eqn , roff
1584 An
1585 .Xr mdoc 7
1586 .Ic \&Bt ,
1587 .Ic \&Ed ,
1588 .Ic \&Ef ,
1589 .Ic \&Ek ,
1590 .Ic \&El ,
1591 .Ic \&Re ,
1592 or
1593 .Ic \&Ud
1594 macro, an
1595 .Ic \&It
1596 macro in a list that don't support item heads, a
1597 .Xr man 7
1598 .Ic \&LP ,
1599 .Ic \&P ,
1600 or
1601 .Ic \&PP
1602 macro, an
1603 .Xr eqn 7
1604 .Ic \&EQ
1605 or
1606 .Ic \&EN
1607 macro, or a
1608 .Xr roff 7
1609 .Sq \&..
1610 block closing request is invoked with at least one argument.
1611 All arguments are ignored.
1612 .It Sy "skipping excess arguments"
1613 .Pq mdoc , man , roff
1614 The
1615 .Ic \&Bf
1616 macro is invoked with more than one argument, the
1617 .Ic \&RE
1618 macro is invoked with more than one argument
1619 or with a non-integer argument, or a request of the
1620 .Ic \&de
1621 family is invoked with more than two arguments.
1622 The excess arguments are ignored.
1623 .El
1624 .Ss Unsupported features
1625 .Bl -ohang
1626 .It Sy "input too large"
1627 .Pq mdoc , man
1628 Currently,
1629 .Nm
1630 cannot handle input files larger than its arbitrary size limit
1631 of 2^31 bytes (2 Gigabytes).
1632 Since useful manuals are always small, this is not a problem in practice.
1633 Parsing is aborted as soon as the condition is detected.
1634 .It Sy "unsupported control character"
1635 .Pq roff
1636 An ASCII control character supported by other
1637 .Xr roff 7
1638 implementations but not by
1639 .Nm
1640 was found in an input file.
1641 It is replaced by a question mark.
1642 .It Sy "unsupported roff request"
1643 .Pq roff
1644 An input file contains a
1645 .Xr roff 7
1646 request supported by GNU troff or Heirloom troff but not by
1647 .Nm ,
1648 and it is likely that this will cause information loss
1649 or considerable misformatting.
1650 .It Sy "eqn delim option in tbl"
1651 .Pq eqn , tbl
1652 The options line of a table defines equation delimiters.
1653 Any equation source code contained in the table will be printed unformatted.
1654 .It Sy "unsupported table layout modifier"
1655 .Pq tbl
1656 A table layout specification contains an
1657 .Sq Cm m
1658 modifier.
1659 The modifier is discarded.
1660 .It Sy "ignoring macro in table"
1661 .Pq tbl , mdoc , man
1662 A table contains an invocation of an
1663 .Xr mdoc 7
1664 or
1665 .Xr man 7
1666 macro or of an undefined macro.
1667 The macro is ignored, and its arguments are handled
1668 as if they were a text line.
1669 .El
1670 .Sh SEE ALSO
1671 .Xr apropos 1 ,
1672 .Xr man 1 ,
1673 .Xr eqn 7 ,
1674 .Xr man 7 ,
1675 .Xr mandoc_char 7 ,
1676 .Xr mdoc 7 ,
1677 .Xr roff 7 ,
1678 .Xr tbl 7
1679 .Sh AUTHORS
1680 The
1681 .Nm
1682 utility was written by
1683 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1684 and is maintained by
1685 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .
1686 .Sh BUGS
1687 In
1688 .Fl T Ns Cm html ,
1689 the maximum size of an element attribute is determined by
1690 .Dv BUFSIZ ,
1691 which is usually 1024 bytes.
1692 Be aware of this when setting long link
1693 formats such as
1694 .Fl O Ns Cm style Ns = Ns Ar really/long/link .