xref: /freebsd/contrib/mandoc/mdoc.7 (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1.\"	$Id: mdoc.7,v 1.287 2021/07/29 17:32:01 schwarze Exp $
2.\"
3.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4.\" Copyright (c) 2010, 2011, 2013-2020 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: July 29 2021 $
19.Dt MDOC 7
20.Os
21.Sh NAME
22.Nm mdoc
23.Nd semantic markup language for formatting manual pages
24.Sh DESCRIPTION
25The
26.Nm mdoc
27language supports authoring of manual pages for the
28.Xr man 1
29utility by allowing semantic annotations of words, phrases,
30page sections and complete manual pages.
31Such annotations are used by formatting tools to achieve a uniform
32presentation across all manuals written in
33.Nm ,
34and to support hyperlinking if supported by the output medium.
35.Pp
36This reference document describes the structure of manual pages
37and the syntax and usage of the
38.Nm
39language.
40The reference implementation of a parsing and formatting tool is
41.Xr mandoc 1 ;
42the
43.Sx COMPATIBILITY
44section describes compatibility with other implementations.
45.Pp
46In an
47.Nm
48document, lines beginning with the control character
49.Sq \&.
50are called
51.Dq macro lines .
52The first word is the macro name.
53It consists of two or three letters.
54Most macro names begin with a capital letter.
55For a list of available macros, see
56.Sx MACRO OVERVIEW .
57The words following the macro name are arguments to the macro, optionally
58including the names of other, callable macros; see
59.Sx MACRO SYNTAX
60for details.
61.Pp
62Lines not beginning with the control character are called
63.Dq text lines .
64They provide free-form text to be printed; the formatting of the text
65depends on the respective processing context:
66.Bd -literal -offset indent
67\&.Sh Macro lines change control state.
68Text lines are interpreted within the current state.
69.Ed
70.Pp
71Many aspects of the basic syntax of the
72.Nm
73language are based on the
74.Xr roff 7
75language; see the
76.Em LANGUAGE SYNTAX
77and
78.Em MACRO SYNTAX
79sections in the
80.Xr roff 7
81manual for details, in particular regarding
82comments, escape sequences, whitespace, and quoting.
83However, using
84.Xr roff 7
85requests in
86.Nm
87documents is discouraged;
88.Xr mandoc 1
89supports some of them merely for backward compatibility.
90.Sh MANUAL STRUCTURE
91A well-formed
92.Nm
93document consists of a document prologue followed by one or more
94sections.
95.Pp
96The prologue, which consists of the
97.Ic \&Dd ,
98.Ic \&Dt ,
99and
100.Ic \&Os
101macros in that order, is required for every document.
102.Pp
103The first section (sections are denoted by
104.Ic \&Sh )
105must be the NAME section, consisting of at least one
106.Ic \&Nm
107followed by
108.Ic \&Nd .
109.Pp
110Following that, convention dictates specifying at least the
111.Em SYNOPSIS
112and
113.Em DESCRIPTION
114sections, although this varies between manual sections.
115.Pp
116The following is a well-formed skeleton
117.Nm
118file for a utility
119.Qq progname :
120.Bd -literal -offset indent
121\&.Dd $\&Mdocdate$
122\&.Dt PROGNAME section
123\&.Os
124\&.Sh NAME
125\&.Nm progname
126\&.Nd one line about what it does
127\&.\e\(dq .Sh LIBRARY
128\&.\e\(dq For sections 2, 3, and 9 only.
129\&.\e\(dq Not used in OpenBSD.
130\&.Sh SYNOPSIS
131\&.Nm progname
132\&.Op Fl options
133\&.Ar
134\&.Sh DESCRIPTION
135The
136\&.Nm
137utility processes files ...
138\&.\e\(dq .Sh CONTEXT
139\&.\e\(dq For section 9 functions only.
140\&.\e\(dq .Sh IMPLEMENTATION NOTES
141\&.\e\(dq Not used in OpenBSD.
142\&.\e\(dq .Sh RETURN VALUES
143\&.\e\(dq For sections 2, 3, and 9 function return values only.
144\&.\e\(dq .Sh ENVIRONMENT
145\&.\e\(dq For sections 1, 6, 7, and 8 only.
146\&.\e\(dq .Sh FILES
147\&.\e\(dq .Sh EXIT STATUS
148\&.\e\(dq For sections 1, 6, and 8 only.
149\&.\e\(dq .Sh EXAMPLES
150\&.\e\(dq .Sh DIAGNOSTICS
151\&.\e\(dq For sections 1, 4, 6, 7, 8, and 9 printf/stderr messages only.
152\&.\e\(dq .Sh ERRORS
153\&.\e\(dq For sections 2, 3, 4, and 9 errno settings only.
154\&.\e\(dq .Sh SEE ALSO
155\&.\e\(dq .Xr foobar 1
156\&.\e\(dq .Sh STANDARDS
157\&.\e\(dq .Sh HISTORY
158\&.\e\(dq .Sh AUTHORS
159\&.\e\(dq .Sh CAVEATS
160\&.\e\(dq .Sh BUGS
161\&.\e\(dq .Sh SECURITY CONSIDERATIONS
162\&.\e\(dq Not used in OpenBSD.
163.Ed
164.Pp
165The sections in an
166.Nm
167document are conventionally ordered as they appear above.
168Sections should be composed as follows:
169.Bl -ohang -offset Ds
170.It Em NAME
171The name(s) and a one line description of the documented material.
172The syntax for this as follows:
173.Bd -literal -offset indent
174\&.Nm name0 ,
175\&.Nm name1 ,
176\&.Nm name2
177\&.Nd a one line description
178.Ed
179.Pp
180Multiple
181.Sq \&Nm
182names should be separated by commas.
183.Pp
184The
185.Ic \&Nm
186macro(s) must precede the
187.Ic \&Nd
188macro.
189.Pp
190See
191.Ic \&Nm
192and
193.Ic \&Nd .
194.It Em LIBRARY
195The name of the library containing the documented material, which is
196assumed to be a function in a section 2, 3, or 9 manual.
197The syntax for this is as follows:
198.Bd -literal -offset indent
199\&.Lb libarm
200.Ed
201.Pp
202See
203.Ic \&Lb .
204.It Em SYNOPSIS
205Documents the utility invocation syntax, function call syntax, or device
206configuration.
207.Pp
208For the first, utilities (sections 1, 6, and 8), this is
209generally structured as follows:
210.Bd -literal -offset indent
211\&.Nm bar
212\&.Op Fl v
213\&.Op Fl o Ar file
214\&.Op Ar
215\&.Nm foo
216\&.Op Fl v
217\&.Op Fl o Ar file
218\&.Op Ar
219.Ed
220.Pp
221Commands should be ordered alphabetically.
222.Pp
223For the second, function calls (sections 2, 3, 9):
224.Bd -literal -offset indent
225\&.In header.h
226\&.Vt extern const char *global;
227\&.Ft "char *"
228\&.Fn foo "const char *src"
229\&.Ft "char *"
230\&.Fn bar "const char *src"
231.Ed
232.Pp
233Ordering of
234.Ic \&In ,
235.Ic \&Vt ,
236.Ic \&Fn ,
237and
238.Ic \&Fo
239macros should follow C header-file conventions.
240.Pp
241And for the third, configurations (section 4):
242.Bd -literal -offset indent
243\&.Cd \(dqit* at isa? port 0x2e\(dq
244\&.Cd \(dqit* at isa? port 0x4e\(dq
245.Ed
246.Pp
247Manuals not in these sections generally don't need a
248.Em SYNOPSIS .
249.Pp
250Some macros are displayed differently in the
251.Em SYNOPSIS
252section, particularly
253.Ic \&Nm ,
254.Ic \&Cd ,
255.Ic \&Fd ,
256.Ic \&Fn ,
257.Ic \&Fo ,
258.Ic \&In ,
259.Ic \&Vt ,
260and
261.Ic \&Ft .
262All of these macros are output on their own line.
263If two such dissimilar macros are pairwise invoked (except for
264.Ic \&Ft
265before
266.Ic \&Fo
267or
268.Ic \&Fn ) ,
269they are separated by a vertical space, unless in the case of
270.Ic \&Fo ,
271.Ic \&Fn ,
272and
273.Ic \&Ft ,
274which are always separated by vertical space.
275.Pp
276When text and macros following an
277.Ic \&Nm
278macro starting an input line span multiple output lines,
279all output lines but the first will be indented to align
280with the text immediately following the
281.Ic \&Nm
282macro, up to the next
283.Ic \&Nm ,
284.Ic \&Sh ,
285or
286.Ic \&Ss
287macro or the end of an enclosing block, whichever comes first.
288.It Em DESCRIPTION
289This begins with an expansion of the brief, one line description in
290.Em NAME :
291.Bd -literal -offset indent
292The
293\&.Nm
294utility does this, that, and the other.
295.Ed
296.Pp
297It usually follows with a breakdown of the options (if documenting a
298command), such as:
299.Bd -literal -offset indent
300The options are as follows:
301\&.Bl \-tag \-width Ds
302\&.It Fl v
303Print verbose information.
304\&.El
305.Ed
306.Pp
307List the options in alphabetical order,
308uppercase before lowercase for each letter and
309with no regard to whether an option takes an argument.
310Put digits in ascending order before all letter options.
311.Pp
312Manuals not documenting a command won't include the above fragment.
313.Pp
314Since the
315.Em DESCRIPTION
316section usually contains most of the text of a manual, longer manuals
317often use the
318.Ic \&Ss
319macro to form subsections.
320In very long manuals, the
321.Em DESCRIPTION
322may be split into multiple sections, each started by an
323.Ic \&Sh
324macro followed by a non-standard section name, and each having
325several subsections, like in the present
326.Nm
327manual.
328.It Em CONTEXT
329This section lists the contexts in which functions can be called in section 9.
330The contexts are autoconf, process, or interrupt.
331.It Em IMPLEMENTATION NOTES
332Implementation-specific notes should be kept here.
333This is useful when implementing standard functions that may have side
334effects or notable algorithmic implications.
335.It Em RETURN VALUES
336This section documents the
337return values of functions in sections 2, 3, and 9.
338.Pp
339See
340.Ic \&Rv .
341.It Em ENVIRONMENT
342Lists the environment variables used by the utility,
343and explains the syntax and semantics of their values.
344The
345.Xr environ 7
346manual provides examples of typical content and formatting.
347.Pp
348See
349.Ic \&Ev .
350.It Em FILES
351Documents files used.
352It's helpful to document both the file name and a short description of how
353the file is used (created, modified, etc.).
354.Pp
355See
356.Ic \&Pa .
357.It Em EXIT STATUS
358This section documents the
359command exit status for section 1, 6, and 8 utilities.
360Historically, this information was described in
361.Em DIAGNOSTICS ,
362a practise that is now discouraged.
363.Pp
364See
365.Ic \&Ex .
366.It Em EXAMPLES
367Example usages.
368This often contains snippets of well-formed, well-tested invocations.
369Make sure that examples work properly!
370.It Em DIAGNOSTICS
371Documents error messages.
372In section 4 and 9 manuals, these are usually messages printed by the
373kernel to the console and to the kernel log.
374In section 1, 6, 7, and 8, these are usually messages printed by
375userland programs to the standard error output.
376.Pp
377Historically, this section was used in place of
378.Em EXIT STATUS
379for manuals in sections 1, 6, and 8; however, this practise is
380discouraged.
381.Pp
382See
383.Ic \&Bl
384.Fl diag .
385.It Em ERRORS
386Documents
387.Xr errno 2
388settings in sections 2, 3, 4, and 9.
389.Pp
390See
391.Ic \&Er .
392.It Em SEE ALSO
393References other manuals with related topics.
394This section should exist for most manuals.
395Cross-references should conventionally be ordered first by section, then
396alphabetically (ignoring case).
397.Pp
398References to other documentation concerning the topic of the manual page,
399for example authoritative books or journal articles, may also be
400provided in this section.
401.Pp
402See
403.Ic \&Rs
404and
405.Ic \&Xr .
406.It Em STANDARDS
407References any standards implemented or used.
408If not adhering to any standards, the
409.Em HISTORY
410section should be used instead.
411.Pp
412See
413.Ic \&St .
414.It Em HISTORY
415A brief history of the subject, including where it was first implemented,
416and when it was ported to or reimplemented for the operating system at hand.
417.It Em AUTHORS
418Credits to the person or persons who wrote the code and/or documentation.
419Authors should generally be noted by both name and email address.
420.Pp
421See
422.Ic \&An .
423.It Em CAVEATS
424Common misuses and misunderstandings should be explained
425in this section.
426.It Em BUGS
427Known bugs, limitations, and work-arounds should be described
428in this section.
429.It Em SECURITY CONSIDERATIONS
430Documents any security precautions that operators should consider.
431.El
432.Sh MACRO OVERVIEW
433This overview is sorted such that macros of similar purpose are listed
434together, to help find the best macro for any given purpose.
435Deprecated macros are not included in the overview, but can be found below
436in the alphabetical
437.Sx MACRO REFERENCE .
438.Ss Document preamble and NAME section macros
439.Bl -column "Brq, Bro, Brc" description
440.It Ic \&Dd Ta document date: Cm $\&Mdocdate$ | Ar month day , year
441.It Ic \&Dt Ta document title: Ar TITLE section Op Ar arch
442.It Ic \&Os Ta operating system version: Op Ar system Op Ar version
443.It Ic \&Nm Ta document name (one argument)
444.It Ic \&Nd Ta document description (one line)
445.El
446.Ss Sections and cross references
447.Bl -column "Brq, Bro, Brc" description
448.It Ic \&Sh Ta section header (one line)
449.It Ic \&Ss Ta subsection header (one line)
450.It Ic \&Sx Ta internal cross reference to a section or subsection
451.It Ic \&Xr Ta cross reference to another manual page: Ar name section
452.It Ic \&Tg Ta tag the definition of a Ar term Pq <= 1 arguments
453.It Ic \&Pp Ta start a text paragraph (no arguments)
454.El
455.Ss Displays and lists
456.Bl -column "Brq, Bro, Brc" description
457.It Ic \&Bd , \&Ed Ta display block:
458.Fl Ar type
459.Op Fl offset Ar width
460.Op Fl compact
461.It Ic \&D1 Ta indented display (one line)
462.It Ic \&Dl Ta indented literal display (one line)
463.It Ic \&Ql Ta in-line literal display: Ql text
464.It Ic \&Bl , \&El Ta list block:
465.Fl Ar type
466.Op Fl width Ar val
467.Op Fl offset Ar val
468.Op Fl compact
469.It Ic \&It Ta list item (syntax depends on Fl Ar type )
470.It Ic \&Ta Ta table cell separator in Ic \&Bl Fl column No lists
471.It Ic \&Rs , \&%* , \&Re Ta bibliographic block (references)
472.El
473.Ss Spacing control
474.Bl -column "Brq, Bro, Brc" description
475.It Ic \&Pf Ta prefix, no following horizontal space (one argument)
476.It Ic \&Ns Ta roman font, no preceding horizontal space (no arguments)
477.It Ic \&Ap Ta apostrophe without surrounding whitespace (no arguments)
478.It Ic \&Sm Ta switch horizontal spacing mode: Op Cm on | off
479.It Ic \&Bk , \&Ek Ta keep block: Fl words
480.El
481.Ss Semantic markup for command line utilities
482.Bl -column "Brq, Bro, Brc" description
483.It Ic \&Nm Ta start a SYNOPSIS block with the name of a utility
484.It Ic \&Fl Ta command line options (flags) (>=0 arguments)
485.It Ic \&Cm Ta command modifier (>0 arguments)
486.It Ic \&Ar Ta command arguments (>=0 arguments)
487.It Ic \&Op , \&Oo , \&Oc Ta optional syntax elements (enclosure)
488.It Ic \&Ic Ta internal or interactive command (>0 arguments)
489.It Ic \&Ev Ta environmental variable (>0 arguments)
490.It Ic \&Pa Ta file system path (>=0 arguments)
491.El
492.Ss Semantic markup for function libraries
493.Bl -column "Brq, Bro, Brc" description
494.It Ic \&Lb Ta function library (one argument)
495.It Ic \&In Ta include file (one argument)
496.It Ic \&Fd Ta other preprocessor directive (>0 arguments)
497.It Ic \&Ft Ta function type (>0 arguments)
498.It Ic \&Fo , \&Fc Ta function block: Ar funcname
499.It Ic \&Fn Ta function name: Ar funcname Op Ar argument ...
500.It Ic \&Fa Ta function argument (>0 arguments)
501.It Ic \&Vt Ta variable type (>0 arguments)
502.It Ic \&Va Ta variable name (>0 arguments)
503.It Ic \&Dv Ta defined variable or preprocessor constant (>0 arguments)
504.It Ic \&Er Ta error constant (>0 arguments)
505.It Ic \&Ev Ta environmental variable (>0 arguments)
506.El
507.Ss Various semantic markup
508.Bl -column "Brq, Bro, Brc" description
509.It Ic \&An Ta author name (>0 arguments)
510.It Ic \&Lk Ta hyperlink: Ar uri Op Ar display_name
511.It Ic \&Mt Ta Do mailto Dc hyperlink: Ar localpart Ns @ Ns Ar domain
512.It Ic \&Cd Ta kernel configuration declaration (>0 arguments)
513.It Ic \&Ad Ta memory address (>0 arguments)
514.It Ic \&Ms Ta mathematical symbol (>0 arguments)
515.El
516.Ss Physical markup
517.Bl -column "Brq, Bro, Brc" description
518.It Ic \&Em Ta italic font or underline (emphasis) (>0 arguments)
519.It Ic \&Sy Ta boldface font (symbolic) (>0 arguments)
520.It Ic \&No Ta return to roman font (normal) (>0 arguments)
521.It Ic \&Bf , \&Ef Ta font block: Fl Ar type | Cm \&Em | \&Li | \&Sy
522.El
523.Ss Physical enclosures
524.Bl -column "Brq, Bro, Brc" description
525.It Ic \&Dq , \&Do , \&Dc Ta enclose in typographic double quotes: Dq text
526.It Ic \&Qq , \&Qo , \&Qc Ta enclose in typewriter double quotes: Qq text
527.It Ic \&Sq , \&So , \&Sc Ta enclose in single quotes: Sq text
528.It Ic \&Pq , \&Po , \&Pc Ta enclose in parentheses: Pq text
529.It Ic \&Bq , \&Bo , \&Bc Ta enclose in square brackets: Bq text
530.It Ic \&Brq , \&Bro , \&Brc Ta enclose in curly braces: Brq text
531.It Ic \&Aq , \&Ao , \&Ac Ta enclose in angle brackets: Aq text
532.It Ic \&Eo , \&Ec Ta generic enclosure
533.El
534.Ss Text production
535.Bl -column "Brq, Bro, Brc" description
536.It Ic \&Ex Fl std Ta standard command exit values: Op Ar utility ...
537.It Ic \&Rv Fl std Ta standard function return values: Op Ar function ...
538.It Ic \&St Ta reference to a standards document (one argument)
539.It Ic \&At Ta At
540.It Ic \&Bx Ta Bx
541.It Ic \&Bsx Ta Bsx
542.It Ic \&Nx Ta Nx
543.It Ic \&Fx Ta Fx
544.It Ic \&Ox Ta Ox
545.It Ic \&Dx Ta Dx
546.El
547.Sh MACRO REFERENCE
548This section is a canonical reference of all macros, arranged
549alphabetically.
550For the scoping of individual macros, see
551.Sx MACRO SYNTAX .
552.Bl -tag -width 3n
553.It Ic \&%A Ar first_name ... last_name
554Author name of an
555.Ic \&Rs
556block.
557Multiple authors should each be accorded their own
558.Ic \%%A
559line.
560Author names should be ordered with full or abbreviated forename(s)
561first, then full surname.
562.It Ic \&%B Ar title
563Book title of an
564.Ic \&Rs
565block.
566This macro may also be used in a non-bibliographic context when
567referring to book titles.
568.It Ic \&%C Ar location
569Publication city or location of an
570.Ic \&Rs
571block.
572.It Ic \&%D Oo Ar month day , Oc Ar year
573Publication date of an
574.Ic \&Rs
575block.
576Provide the full English name of the
577.Ar month
578and all four digits of the
579.Ar year .
580.It Ic \&%I Ar name
581Publisher or issuer name of an
582.Ic \&Rs
583block.
584.It Ic \&%J Ar name
585Journal name of an
586.Ic \&Rs
587block.
588.It Ic \&%N Ar number
589Issue number (usually for journals) of an
590.Ic \&Rs
591block.
592.It Ic \&%O Ar line
593Optional information of an
594.Ic \&Rs
595block.
596.It Ic \&%P Ar number
597Book or journal page number of an
598.Ic \&Rs
599block.
600Conventionally, the argument starts with
601.Ql p.\&
602for a single page or
603.Ql pp.\&
604for a range of pages, for example:
605.Pp
606.Dl .%P pp. 42\e(en47
607.It Ic \&%Q Ar name
608Institutional author (school, government, etc.) of an
609.Ic \&Rs
610block.
611Multiple institutional authors should each be accorded their own
612.Ic \&%Q
613line.
614.It Ic \&%R Ar name
615Technical report name of an
616.Ic \&Rs
617block.
618.It Ic \&%T Ar title
619Article title of an
620.Ic \&Rs
621block.
622This macro may also be used in a non-bibliographical context when
623referring to article titles.
624.It Ic \&%U Ar protocol Ns :// Ns Ar path
625URI of reference document.
626.It Ic \&%V Ar number
627Volume number of an
628.Ic \&Rs
629block.
630.It Ic \&Ac
631Close an
632.Ic \&Ao
633block.
634Does not have any tail arguments.
635.Tg Ad
636.It Ic \&Ad Ar address
637Memory address.
638Do not use this for postal addresses.
639.Pp
640Examples:
641.Dl \&.Ad [0,$]
642.Dl \&.Ad 0x00000000
643.Tg An
644.It Ic \&An Fl split | nosplit | Ar first_name ... last_name
645Author name.
646Can be used both for the authors of the program, function, or driver
647documented in the manual, or for the authors of the manual itself.
648Requires either the name of an author or one of the following arguments:
649.Pp
650.Bl -tag -width "-nosplitX" -offset indent -compact
651.It Fl split
652Start a new output line before each subsequent invocation of
653.Ic \&An .
654.It Fl nosplit
655The opposite of
656.Fl split .
657.El
658.Pp
659The default is
660.Fl nosplit .
661The effect of selecting either of the
662.Fl split
663modes ends at the beginning of the
664.Em AUTHORS
665section.
666In the
667.Em AUTHORS
668section, the default is
669.Fl nosplit
670for the first author listing and
671.Fl split
672for all other author listings.
673.Pp
674Examples:
675.Dl \&.An -nosplit
676.Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
677.It Ic \&Ao Ar block
678Begin a block enclosed by angle brackets.
679Does not have any head arguments.
680This macro is almost never useful.
681See
682.Ic \&Aq
683for more details.
684.Tg Ap
685.It Ic \&Ap
686Inserts an apostrophe without any surrounding whitespace.
687This is generally used as a grammatical device when referring to the verb
688form of a function.
689.Pp
690Examples:
691.Dl \&.Fn execve \&Ap d
692.Tg Aq
693.It Ic \&Aq Ar line
694Enclose the rest of the input line in angle brackets.
695The only important use case is for email addresses.
696See
697.Ic \&Mt
698for an example.
699.Pp
700Occasionally, it is used for names of characters and keys, for example:
701.Bd -literal -offset indent
702Press the
703\&.Aq escape
704key to ...
705.Ed
706.Pp
707For URIs, use
708.Ic \&Lk
709instead, and
710.Ic \&In
711for
712.Dq #include
713directives.
714Never wrap
715.Ic \&Ar
716in
717.Ic \&Aq .
718.Pp
719Since
720.Ic \&Aq
721usually renders with non-ASCII characters in non-ASCII output modes,
722do not use it where the ASCII characters
723.Sq <
724and
725.Sq >
726are required as syntax elements.
727Instead, use these characters directly in such cases, combining them
728with the macros
729.Ic \&Pf ,
730.Ic \&Ns ,
731or
732.Ic \&Eo
733as needed.
734.Pp
735See also
736.Ic \&Ao .
737.Tg Ar
738.It Ic \&Ar Op Ar placeholder ...
739Command arguments.
740If an argument is not provided, the string
741.Dq file ...\&
742is used as a default.
743.Pp
744Examples:
745.Dl ".Fl o Ar file"
746.Dl ".Ar"
747.Dl ".Ar arg1 , arg2 ."
748.Pp
749The arguments to the
750.Ic \&Ar
751macro are names and placeholders for command arguments;
752for fixed strings to be passed verbatim as arguments, use
753.Ic \&Fl
754or
755.Ic \&Cm .
756.Tg At
757.It Ic \&At Op Ar version
758Formats an
759.At
760version.
761Accepts one optional argument:
762.Pp
763.Bl -tag -width "v[1-7] | 32vX" -offset indent -compact
764.It Cm v[1-7] | 32v
765A version of
766.At .
767.It Cm III
768.At III .
769.It Cm V | V.[1-4]
770A version of
771.At V .
772.El
773.Pp
774Note that these arguments do not begin with a hyphen.
775.Pp
776Examples:
777.Dl \&.At
778.Dl \&.At III
779.Dl \&.At V.1
780.Pp
781See also
782.Ic \&Bsx ,
783.Ic \&Bx ,
784.Ic \&Dx ,
785.Ic \&Fx ,
786.Ic \&Nx ,
787and
788.Ic \&Ox .
789.It Ic \&Bc
790Close a
791.Ic \&Bo
792block.
793Does not have any tail arguments.
794.Tg Bd
795.It Ic \&Bd Fl Ns Ar type Oo Fl offset Ar width Oc Op Fl compact
796Begin a display block.
797Display blocks are used to select a different indentation and
798justification than the one used by the surrounding text.
799They may contain both macro lines and text lines.
800By default, a display block is preceded by a vertical space.
801.Pp
802The
803.Ar type
804must be one of the following:
805.Bl -tag -width 13n -offset indent
806.It Fl centered
807Produce one output line from each input line, and center-justify each line.
808Using this display type is not recommended; many
809.Nm
810implementations render it poorly.
811.It Fl filled
812Change the positions of line breaks to fill each line, and left- and
813right-justify the resulting block.
814.It Fl literal
815Produce one output line from each input line,
816and do not justify the block at all.
817Preserve white space as it appears in the input.
818Always use a constant-width font.
819Use this for displaying source code.
820.It Fl ragged
821Change the positions of line breaks to fill each line, and left-justify
822the resulting block.
823.It Fl unfilled
824The same as
825.Fl literal ,
826but using the same font as for normal text, which is a variable width font
827if supported by the output device.
828.El
829.Pp
830The
831.Ar type
832must be provided first.
833Additional arguments may follow:
834.Bl -tag -width 13n -offset indent
835.It Fl offset Ar width
836Indent the display by the
837.Ar width ,
838which may be one of the following:
839.Bl -item
840.It
841One of the pre-defined strings
842.Cm indent ,
843the width of a standard indentation (six constant width characters);
844.Cm indent-two ,
845twice
846.Cm indent ;
847.Cm left ,
848which has no effect;
849.Cm right ,
850which justifies to the right margin; or
851.Cm center ,
852which aligns around an imagined center axis.
853.It
854A macro invocation, which selects a predefined width
855associated with that macro.
856The most popular is the imaginary macro
857.Ar \&Ds ,
858which resolves to
859.Sy 6n .
860.It
861A scaling width as described in
862.Xr roff 7 .
863.It
864An arbitrary string, which indents by the length of this string.
865.El
866.Pp
867When the argument is missing,
868.Fl offset
869is ignored.
870.It Fl compact
871Do not assert vertical space before the display.
872.El
873.Pp
874Examples:
875.Bd -literal -offset indent
876\&.Bd \-literal \-offset indent \-compact
877   Hello       world.
878\&.Ed
879.Ed
880.Pp
881See also
882.Ic \&D1
883and
884.Ic \&Dl .
885.Tg Bf
886.It Ic \&Bf Fl emphasis | literal | symbolic | Cm \&Em | \&Li | \&Sy
887Change the font mode for a scoped block of text.
888The
889.Fl emphasis
890and
891.Cm \&Em
892argument are equivalent, as are
893.Fl symbolic
894and
895.Cm \&Sy ,
896and
897.Fl literal
898and
899.Cm \&Li .
900Without an argument, this macro does nothing.
901The font mode continues until broken by a new font mode in a nested
902scope or
903.Ic \&Ef
904is encountered.
905.Pp
906See also
907.Ic \&Li ,
908.Ic \&Ef ,
909.Ic \&Em ,
910and
911.Ic \&Sy .
912.Tg Bk
913.It Ic \&Bk Fl words
914For each macro, keep its output together on the same output line,
915until the end of the macro or the end of the input line is reached,
916whichever comes first.
917Line breaks in text lines are unaffected.
918.Pp
919The
920.Fl words
921argument is required; additional arguments are ignored.
922.Pp
923The following example will not break within each
924.Ic \&Op
925macro line:
926.Bd -literal -offset indent
927\&.Bk \-words
928\&.Op Fl f Ar flags
929\&.Op Fl o Ar output
930\&.Ek
931.Ed
932.Pp
933Be careful in using over-long lines within a keep block!
934Doing so will clobber the right margin.
935.Tg Bl
936.It Xo
937.Ic \&Bl
938.Fl Ns Ar type
939.Op Fl width Ar val
940.Op Fl offset Ar val
941.Op Fl compact
942.Op Ar col ...
943.Xc
944Begin a list.
945Lists consist of items specified using the
946.Ic \&It
947macro, containing a head or a body or both.
948.Pp
949The list
950.Ar type
951is mandatory and must be specified first.
952The
953.Fl width
954and
955.Fl offset
956arguments accept macro names as described for
957.Ic \&Bd
958.Fl offset ,
959scaling widths as described in
960.Xr roff 7 ,
961or use the length of the given string.
962The
963.Fl offset
964is a global indentation for the whole list, affecting both item heads
965and bodies.
966For those list types supporting it, the
967.Fl width
968argument requests an additional indentation of item bodies,
969to be added to the
970.Fl offset .
971Unless the
972.Fl compact
973argument is specified, list entries are separated by vertical space.
974.Pp
975A list must specify one of the following list types:
976.Bl -tag -width 12n -offset indent
977.It Fl bullet
978No item heads can be specified, but a bullet will be printed at the head
979of each item.
980Item bodies start on the same output line as the bullet
981and are indented according to the
982.Fl width
983argument.
984.It Fl column
985A columnated list.
986The
987.Fl width
988argument has no effect; instead, the string length of each argument
989specifies the width of one column.
990If the first line of the body of a
991.Fl column
992list is not an
993.Ic \&It
994macro line,
995.Ic \&It
996contexts spanning one input line each are implied until an
997.Ic \&It
998macro line is encountered, at which point items start being interpreted as
999described in the
1000.Ic \&It
1001documentation.
1002.It Fl dash
1003Like
1004.Fl bullet ,
1005except that dashes are used in place of bullets.
1006.It Fl diag
1007Like
1008.Fl inset ,
1009except that item heads are not parsed for macro invocations.
1010Most often used in the
1011.Em DIAGNOSTICS
1012section with error constants in the item heads.
1013.It Fl enum
1014A numbered list.
1015No item heads can be specified.
1016Formatted like
1017.Fl bullet ,
1018except that cardinal numbers are used in place of bullets,
1019starting at 1.
1020.It Fl hang
1021Like
1022.Fl tag ,
1023except that the first lines of item bodies are not indented, but follow
1024the item heads like in
1025.Fl inset
1026lists.
1027.It Fl hyphen
1028Synonym for
1029.Fl dash .
1030.It Fl inset
1031Item bodies follow items heads on the same line, using normal inter-word
1032spacing.
1033Bodies are not indented, and the
1034.Fl width
1035argument is ignored.
1036.It Fl item
1037No item heads can be specified, and none are printed.
1038Bodies are not indented, and the
1039.Fl width
1040argument is ignored.
1041.It Fl ohang
1042Item bodies start on the line following item heads and are not indented.
1043The
1044.Fl width
1045argument is ignored.
1046.It Fl tag
1047Item bodies are indented according to the
1048.Fl width
1049argument.
1050When an item head fits inside the indentation, the item body follows
1051this head on the same output line.
1052Otherwise, the body starts on the output line following the head.
1053.El
1054.Pp
1055Lists may be nested within lists and displays.
1056Nesting of
1057.Fl column
1058and
1059.Fl enum
1060lists may not be portable.
1061.Pp
1062See also
1063.Ic \&El
1064and
1065.Ic \&It .
1066.It Ic \&Bo Ar block
1067Begin a block enclosed by square brackets.
1068Does not have any head arguments.
1069.Pp
1070Examples:
1071.Bd -literal -offset indent -compact
1072\&.Bo 1 ,
1073\&.Dv BUFSIZ \&Bc
1074.Ed
1075.Pp
1076See also
1077.Ic \&Bq .
1078.Tg Bq
1079.It Ic \&Bq Ar line
1080Encloses its arguments in square brackets.
1081.Pp
1082Examples:
1083.Dl \&.Bq 1 , \&Dv BUFSIZ
1084.Pp
1085.Em Remarks :
1086this macro is sometimes abused to emulate optional arguments for
1087commands; the correct macros to use for this purpose are
1088.Ic \&Op ,
1089.Ic \&Oo ,
1090and
1091.Ic \&Oc .
1092.Pp
1093See also
1094.Ic \&Bo .
1095.It Ic \&Brc
1096Close a
1097.Ic \&Bro
1098block.
1099Does not have any tail arguments.
1100.It Ic \&Bro Ar block
1101Begin a block enclosed by curly braces.
1102Does not have any head arguments.
1103.Pp
1104Examples:
1105.Bd -literal -offset indent -compact
1106\&.Bro 1 , ... ,
1107\&.Va n \&Brc
1108.Ed
1109.Pp
1110See also
1111.Ic \&Brq .
1112.Tg Brq
1113.It Ic \&Brq Ar line
1114Encloses its arguments in curly braces.
1115.Pp
1116Examples:
1117.Dl \&.Brq 1 , ... , \&Va n
1118.Pp
1119See also
1120.Ic \&Bro .
1121.Tg Bsx
1122.It Ic \&Bsx Op Ar version
1123Format the
1124.Bsx
1125version provided as an argument, or a default value if
1126no argument is provided.
1127.Pp
1128Examples:
1129.Dl \&.Bsx 1.0
1130.Dl \&.Bsx
1131.Pp
1132See also
1133.Ic \&At ,
1134.Ic \&Bx ,
1135.Ic \&Dx ,
1136.Ic \&Fx ,
1137.Ic \&Nx ,
1138and
1139.Ic \&Ox .
1140.It Ic \&Bt
1141Supported only for compatibility, do not use this in new manuals.
1142Prints
1143.Dq is currently in beta test.
1144.Tg Bx
1145.It Ic \&Bx Op Ar version Op Ar variant
1146Format the
1147.Bx
1148version provided as an argument, or a default value if no
1149argument is provided.
1150.Pp
1151Examples:
1152.Dl \&.Bx 4.3 Tahoe
1153.Dl \&.Bx 4.4
1154.Dl \&.Bx
1155.Pp
1156See also
1157.Ic \&At ,
1158.Ic \&Bsx ,
1159.Ic \&Dx ,
1160.Ic \&Fx ,
1161.Ic \&Nx ,
1162and
1163.Ic \&Ox .
1164.Tg Cd
1165.It Ic \&Cd Ar line
1166Kernel configuration declaration.
1167This denotes strings accepted by
1168.Xr config 8 .
1169It is most often used in section 4 manual pages.
1170.Pp
1171Examples:
1172.Dl \&.Cd device le0 at scode?
1173.Pp
1174.Em Remarks :
1175this macro is commonly abused by using quoted literals to retain
1176whitespace and align consecutive
1177.Ic \&Cd
1178declarations.
1179This practise is discouraged.
1180.Tg Cm
1181.It Ic \&Cm Ar keyword ...
1182Command modifiers.
1183Typically used for fixed strings passed as arguments to interactive
1184commands, to commands in interpreted scripts, or to configuration
1185file directives, unless
1186.Ic \&Fl
1187is more appropriate.
1188.Pp
1189Examples:
1190.Dl ".Nm mt Fl f Ar device Cm rewind"
1191.Dl ".Nm ps Fl o Cm pid , Ns Cm command"
1192.Dl ".Nm dd Cm if= Ns Ar file1 Cm of= Ns Ar file2"
1193.Dl ".Ic set Fl o Cm vi"
1194.Dl ".Ic lookup Cm file bind"
1195.Dl ".Ic permit Ar identity Op Cm as Ar target"
1196.Tg D1
1197.It Ic \&D1 Ar line
1198One-line indented display.
1199This is formatted by the default rules and is useful for simple indented
1200statements.
1201It is followed by a newline.
1202.Pp
1203Examples:
1204.Dl \&.D1 \&Fl abcdefgh
1205.Pp
1206See also
1207.Ic \&Bd
1208and
1209.Ic \&Dl .
1210.It Ic \&Db
1211This macro is obsolete.
1212No replacement is needed.
1213It is ignored by
1214.Xr mandoc 1
1215and groff including its arguments.
1216It was formerly used to toggle a debugging mode.
1217.It Ic \&Dc
1218Close a
1219.Ic \&Do
1220block.
1221Does not have any tail arguments.
1222.Tg Dd
1223.It Ic \&Dd Cm $\&Mdocdate$ | Ar month day , year
1224Document date for display in the page footer,
1225by convention the date of the last change.
1226This is the mandatory first macro of any
1227.Nm
1228manual.
1229.Pp
1230The
1231.Ar month
1232is the full English month name, the
1233.Ar day
1234is an integer number, and the
1235.Ar year
1236is the full four-digit year.
1237.Pp
1238Other arguments are not portable; the
1239.Xr mandoc 1
1240utility handles them as follows:
1241.Bl -dash -offset 3n -compact
1242.It
1243To have the date automatically filled in by the
1244.Ox
1245version of
1246.Xr cvs 1 ,
1247the special string
1248.Dq $\&Mdocdate$
1249can be given as an argument.
1250.It
1251The traditional, purely numeric
1252.Xr man 7
1253format
1254.Ar year Ns \(en Ns Ar month Ns \(en Ns Ar day
1255is accepted, too.
1256.It
1257If a date string cannot be parsed, it is used verbatim.
1258.It
1259If no date string is given, the current date is used.
1260.El
1261.Pp
1262Examples:
1263.Dl \&.Dd $\&Mdocdate$
1264.Dl \&.Dd $\&Mdocdate: July 2 2018$
1265.Dl \&.Dd July 2, 2018
1266.Pp
1267See also
1268.Ic \&Dt
1269and
1270.Ic \&Os .
1271.Tg Dl
1272.It Ic \&Dl Ar line
1273One-line indented display.
1274This is formatted as literal text and is useful for commands and
1275invocations.
1276It is followed by a newline.
1277.Pp
1278Examples:
1279.Dl \&.Dl % mandoc mdoc.7 \e(ba less
1280.Pp
1281See also
1282.Ic \&Ql ,
1283.Ic \&Bd Fl literal ,
1284and
1285.Ic \&D1 .
1286.It Ic \&Do Ar block
1287Begin a block enclosed by double quotes.
1288Does not have any head arguments.
1289.Pp
1290Examples:
1291.Bd -literal -offset indent -compact
1292\&.Do
1293April is the cruellest month
1294\&.Dc
1295\e(em T.S. Eliot
1296.Ed
1297.Pp
1298See also
1299.Ic \&Dq .
1300.Tg Dq
1301.It Ic \&Dq Ar line
1302Encloses its arguments in
1303.Dq typographic
1304double-quotes.
1305.Pp
1306Examples:
1307.Bd -literal -offset indent -compact
1308\&.Dq April is the cruellest month
1309\e(em T.S. Eliot
1310.Ed
1311.Pp
1312See also
1313.Ic \&Qq ,
1314.Ic \&Sq ,
1315and
1316.Ic \&Do .
1317.Tg Dt
1318.It Ic \&Dt Ar TITLE section Op Ar arch
1319Document title for display in the page header.
1320This is the mandatory second macro of any
1321.Nm
1322file.
1323.Pp
1324Its arguments are as follows:
1325.Bl -tag -width section -offset 2n
1326.It Ar TITLE
1327The document's title (name), defaulting to
1328.Dq UNTITLED
1329if unspecified.
1330To achieve a uniform appearance of page header lines,
1331it should by convention be all caps.
1332.It Ar section
1333The manual section.
1334This may be one of
1335.Cm 1
1336.Pq General Commands ,
1337.Cm 2
1338.Pq System Calls ,
1339.Cm 3
1340.Pq Library Functions ,
1341.Cm 3p
1342.Pq Perl Library ,
1343.Cm 4
1344.Pq Device Drivers ,
1345.Cm 5
1346.Pq File Formats ,
1347.Cm 6
1348.Pq Games ,
1349.Cm 7
1350.Pq Miscellaneous Information ,
1351.Cm 8
1352.Pq System Manager's Manual ,
1353or
1354.Cm 9
1355.Pq Kernel Developer's Manual .
1356It should correspond to the manual's filename suffix and defaults to
1357the empty string if unspecified.
1358.It Ar arch
1359This specifies the machine architecture a manual page applies to,
1360where relevant, for example
1361.Cm alpha ,
1362.Cm amd64 ,
1363.Cm i386 ,
1364or
1365.Cm sparc64 .
1366The list of valid architectures varies by operating system.
1367.El
1368.Pp
1369Examples:
1370.Dl \&.Dt FOO 1
1371.Dl \&.Dt FOO 9 i386
1372.Pp
1373See also
1374.Ic \&Dd
1375and
1376.Ic \&Os .
1377.Tg Dv
1378.It Ic \&Dv Ar identifier ...
1379Defined variables such as preprocessor constants, constant symbols,
1380enumeration values, and so on.
1381.Pp
1382Examples:
1383.Dl \&.Dv NULL
1384.Dl \&.Dv BUFSIZ
1385.Dl \&.Dv STDOUT_FILENO
1386.Pp
1387See also
1388.Ic \&Er
1389and
1390.Ic \&Ev
1391for special-purpose constants,
1392.Ic \&Va
1393for variable symbols, and
1394.Ic \&Fd
1395for listing preprocessor variable definitions in the
1396.Em SYNOPSIS .
1397.Tg Dx
1398.It Ic \&Dx Op Ar version
1399Format the
1400.Dx
1401version provided as an argument, or a default
1402value if no argument is provided.
1403.Pp
1404Examples:
1405.Dl \&.Dx 2.4.1
1406.Dl \&.Dx
1407.Pp
1408See also
1409.Ic \&At ,
1410.Ic \&Bsx ,
1411.Ic \&Bx ,
1412.Ic \&Fx ,
1413.Ic \&Nx ,
1414and
1415.Ic \&Ox .
1416.It Ic \&Ec Op Ar closing_delimiter
1417Close a scope started by
1418.Ic \&Eo .
1419.Pp
1420The
1421.Ar closing_delimiter
1422argument is used as the enclosure tail, for example, specifying \e(rq
1423will emulate
1424.Ic \&Dc .
1425.It Ic \&Ed
1426End a display context started by
1427.Ic \&Bd .
1428.It Ic \&Ef
1429End a font mode context started by
1430.Ic \&Bf .
1431.It Ic \&Ek
1432End a keep context started by
1433.Ic \&Bk .
1434.It Ic \&El
1435End a list context started by
1436.Ic \&Bl .
1437See also
1438.Ic \&It .
1439.Tg Em
1440.It Ic \&Em Ar word ...
1441Request an italic font.
1442If the output device does not provide that, underline.
1443.Pp
1444This is most often used for stress emphasis (not to be confused with
1445importance, see
1446.Ic \&Sy ) .
1447In the rare cases where none of the semantic markup macros fit,
1448it can also be used for technical terms and placeholders, except
1449that for syntax elements,
1450.Ic \&Sy
1451and
1452.Ic \&Ar
1453are preferred, respectively.
1454.Pp
1455Examples:
1456.Bd -literal -compact -offset indent
1457Selected lines are those
1458\&.Em not
1459matching any of the specified patterns.
1460Some of the functions use a
1461\&.Em hold space
1462to save the pattern space for subsequent retrieval.
1463.Ed
1464.Pp
1465See also
1466.Ic \&No ,
1467.Ic \&Ql ,
1468and
1469.Ic \&Sy .
1470.It Ic \&En Ar word ...
1471This macro is obsolete.
1472Use
1473.Ic \&Eo
1474or any of the other enclosure macros.
1475.Pp
1476It encloses its argument in the delimiters specified by the last
1477.Ic \&Es
1478macro.
1479.Tg Eo
1480.It Ic \&Eo Op Ar opening_delimiter
1481An arbitrary enclosure.
1482The
1483.Ar opening_delimiter
1484argument is used as the enclosure head, for example, specifying \e(lq
1485will emulate
1486.Ic \&Do .
1487.Tg Er
1488.It Ic \&Er Ar identifier ...
1489Error constants for definitions of the
1490.Va errno
1491libc global variable.
1492This is most often used in section 2 and 3 manual pages.
1493.Pp
1494Examples:
1495.Dl \&.Er EPERM
1496.Dl \&.Er ENOENT
1497.Pp
1498See also
1499.Ic \&Dv
1500for general constants.
1501.It Ic \&Es Ar opening_delimiter closing_delimiter
1502This macro is obsolete.
1503Use
1504.Ic \&Eo
1505or any of the other enclosure macros.
1506.Pp
1507It takes two arguments, defining the delimiters to be used by subsequent
1508.Ic \&En
1509macros.
1510.Tg Ev
1511.It Ic \&Ev Ar identifier ...
1512Environmental variables such as those specified in
1513.Xr environ 7 .
1514.Pp
1515Examples:
1516.Dl \&.Ev DISPLAY
1517.Dl \&.Ev PATH
1518.Pp
1519See also
1520.Ic \&Dv
1521for general constants.
1522.Tg Ex
1523.It Ic \&Ex Fl std Op Ar utility ...
1524Insert a standard sentence regarding command exit values of 0 on success
1525and >0 on failure.
1526This is most often used in section 1, 6, and 8 manual pages.
1527.Pp
1528If
1529.Ar utility
1530is not specified, the document's name set by
1531.Ic \&Nm
1532is used.
1533Multiple
1534.Ar utility
1535arguments are treated as separate utilities.
1536.Pp
1537See also
1538.Ic \&Rv .
1539.Tg Fa
1540.It Ic \&Fa Ar argument ...
1541Function argument or parameter.
1542Each argument may be a name and a type (recommended for the
1543.Em SYNOPSIS
1544section), a name alone (for function invocations),
1545or a type alone (for function prototypes).
1546If both a type and a name are given or if the type consists of multiple
1547words, all words belonging to the same function argument have to be
1548given in a single argument to the
1549.Ic \&Fa
1550macro.
1551.Pp
1552This macro is also used to specify the field name of a structure.
1553.Pp
1554Most often, the
1555.Ic \&Fa
1556macro is used in the
1557.Em SYNOPSIS
1558within
1559.Ic \&Fo
1560blocks when documenting multi-line function prototypes.
1561If invoked with multiple arguments, the arguments are separated by a
1562comma.
1563Furthermore, if the following macro is another
1564.Ic \&Fa ,
1565the last argument will also have a trailing comma.
1566.Pp
1567Examples:
1568.Dl \&.Fa \(dqconst char *p\(dq
1569.Dl \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
1570.Dl \&.Fa \(dqchar *\(dq size_t
1571.Pp
1572See also
1573.Ic \&Fo .
1574.It Ic \&Fc
1575End a function context started by
1576.Ic \&Fo .
1577.Tg Fd
1578.It Ic \&Fd Pf # Ar directive Op Ar argument ...
1579Preprocessor directive, in particular for listing it in the
1580.Em SYNOPSIS .
1581Historically, it was also used to document include files.
1582The latter usage has been deprecated in favour of
1583.Ic \&In .
1584.Pp
1585Examples:
1586.Dl \&.Fd #define sa_handler __sigaction_u.__sa_handler
1587.Dl \&.Fd #define SIO_MAXNFDS
1588.Dl \&.Fd #ifdef FS_DEBUG
1589.Dl \&.Ft void
1590.Dl \&.Fn dbg_open \(dqconst char *\(dq
1591.Dl \&.Fd #endif
1592.Pp
1593See also
1594.Sx MANUAL STRUCTURE ,
1595.Ic \&In ,
1596and
1597.Ic \&Dv .
1598.Tg Fl
1599.It Ic \&Fl Op Ar word ...
1600Command-line flag or option.
1601Used when listing arguments to command-line utilities.
1602For each argument, prints an ASCII hyphen-minus character
1603.Sq \- ,
1604immediately followed by the argument.
1605If no arguments are provided, a hyphen-minus is printed followed by a space.
1606If the argument is a macro, a hyphen-minus is prefixed
1607to the subsequent macro output.
1608.Pp
1609Examples:
1610.Dl ".Nm du Op Fl H | L | P"
1611.Dl ".Nm ls Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux"
1612.Dl ".Nm route Cm add Fl inet Ar destination gateway"
1613.Dl ".Nm locate.updatedb Op Fl \e-fcodes Ns = Ns Ar dbfile"
1614.Dl ".Nm aucat Fl o Fl"
1615.Dl ".Nm kill Fl Ar signal_number"
1616.Pp
1617For GNU-sytle long options, escaping the additional hyphen-minus is not
1618strictly required, but may be safer with future versions of GNU troff; see
1619.Xr mandoc_char 7
1620for details.
1621.Pp
1622See also
1623.Ic \&Cm .
1624.Tg Fn
1625.It Ic \&Fn Ar funcname Op Ar argument ...
1626A function name.
1627.Pp
1628Function arguments are surrounded in parenthesis and
1629are delimited by commas.
1630If no arguments are specified, blank parenthesis are output.
1631In the
1632.Em SYNOPSIS
1633section, this macro starts a new output line,
1634and a blank line is automatically inserted between function definitions.
1635.Pp
1636Examples:
1637.Dl \&.Fn \(dqint funcname\(dq \(dqint arg0\(dq \(dqint arg1\(dq
1638.Dl \&.Fn funcname \(dqint arg0\(dq
1639.Dl \&.Fn funcname arg0
1640.Bd -literal -offset indent
1641\&.Ft functype
1642\&.Fn funcname
1643.Ed
1644.Pp
1645When referring to a function documented in another manual page, use
1646.Ic \&Xr
1647instead.
1648See also
1649.Sx MANUAL STRUCTURE ,
1650.Ic \&Fo ,
1651and
1652.Ic \&Ft .
1653.Tg Fo
1654.It Ic \&Fo Ar funcname
1655Begin a function block.
1656This is a multi-line version of
1657.Ic \&Fn .
1658.Pp
1659Invocations usually occur in the following context:
1660.Bd -ragged -offset indent
1661.Pf \. Ic \&Ft Ar functype
1662.br
1663.Pf \. Ic \&Fo Ar funcname
1664.br
1665.Pf \. Ic \&Fa Qq Ar argtype Ar argname
1666.br
1667\&.\.\.
1668.br
1669.Pf \. Ic \&Fc
1670.Ed
1671.Pp
1672A
1673.Ic \&Fo
1674scope is closed by
1675.Ic \&Fc .
1676.Pp
1677See also
1678.Sx MANUAL STRUCTURE ,
1679.Ic \&Fa ,
1680.Ic \&Fc ,
1681and
1682.Ic \&Ft .
1683.It Ic \&Fr Ar number
1684This macro is obsolete.
1685No replacement markup is needed.
1686.Pp
1687It was used to show numerical function return values in an italic font.
1688.Tg Ft
1689.It Ic \&Ft Ar functype
1690A function type.
1691.Pp
1692In the
1693.Em SYNOPSIS
1694section, a new output line is started after this macro.
1695.Pp
1696Examples:
1697.Dl \&.Ft int
1698.Bd -literal -offset indent -compact
1699\&.Ft functype
1700\&.Fn funcname
1701.Ed
1702.Pp
1703See also
1704.Sx MANUAL STRUCTURE ,
1705.Ic \&Fn ,
1706and
1707.Ic \&Fo .
1708.Tg Fx
1709.It Ic \&Fx Op Ar version
1710Format the
1711.Fx
1712version provided as an argument, or a default value
1713if no argument is provided.
1714.Pp
1715Examples:
1716.Dl \&.Fx 7.1
1717.Dl \&.Fx
1718.Pp
1719See also
1720.Ic \&At ,
1721.Ic \&Bsx ,
1722.Ic \&Bx ,
1723.Ic \&Dx ,
1724.Ic \&Nx ,
1725and
1726.Ic \&Ox .
1727.It Ic \&Hf Ar filename
1728This macro is not implemented in
1729.Xr mandoc 1 .
1730It was used to include the contents of a (header) file literally.
1731.Tg Ic
1732.It Ic \&Ic Ar keyword ...
1733Internal or interactive command, or configuration instruction
1734in a configuration file.
1735See also
1736.Ic \&Cm .
1737.Pp
1738Examples:
1739.Dl \&.Ic :wq
1740.Dl \&.Ic hash
1741.Dl \&.Ic alias
1742.Pp
1743Note that using
1744.Ic \&Ql ,
1745.Ic \&Dl ,
1746or
1747.Ic \&Bd Fl literal
1748is preferred for displaying code samples; the
1749.Ic \&Ic
1750macro is used when referring to an individual command name.
1751.Tg In
1752.It Ic \&In Ar filename
1753The name of an include file.
1754This macro is most often used in section 2, 3, and 9 manual pages.
1755.Pp
1756When invoked as the first macro on an input line in the
1757.Em SYNOPSIS
1758section, the argument is displayed in angle brackets
1759and preceded by
1760.Qq #include ,
1761and a blank line is inserted in front if there is a preceding
1762function declaration.
1763In other sections, it only encloses its argument in angle brackets
1764and causes no line break.
1765.Pp
1766Examples:
1767.Dl \&.In sys/types.h
1768.Pp
1769See also
1770.Sx MANUAL STRUCTURE .
1771.Tg It
1772.It Ic \&It Op Ar head
1773A list item.
1774The syntax of this macro depends on the list type.
1775.Pp
1776Lists
1777of type
1778.Fl hang ,
1779.Fl ohang ,
1780.Fl inset ,
1781and
1782.Fl diag
1783have the following syntax:
1784.Pp
1785.D1 Pf \. Ic \&It Ar args
1786.Pp
1787Lists of type
1788.Fl bullet ,
1789.Fl dash ,
1790.Fl enum ,
1791.Fl hyphen
1792and
1793.Fl item
1794have the following syntax:
1795.Pp
1796.D1 Pf \. Ic \&It
1797.Pp
1798with subsequent lines interpreted within the scope of the
1799.Ic \&It
1800until either a closing
1801.Ic \&El
1802or another
1803.Ic \&It .
1804.Pp
1805The
1806.Fl tag
1807list has the following syntax:
1808.Pp
1809.D1 Pf \. Ic \&It Op Cm args
1810.Pp
1811Subsequent lines are interpreted as with
1812.Fl bullet
1813and family.
1814The line arguments correspond to the list's left-hand side; body
1815arguments correspond to the list's contents.
1816.Pp
1817The
1818.Fl column
1819list is the most complicated.
1820Its syntax is as follows:
1821.Pp
1822.D1 Pf \. Ic \&It Ar cell Op Ic \&Ta Ar cell ...
1823.D1 Pf \. Ic \&It Ar cell Op <TAB> Ar cell ...
1824.Pp
1825The arguments consist of one or more lines of text and macros
1826representing a complete table line.
1827Cells within the line are delimited by the special
1828.Ic \&Ta
1829block macro or by literal tab characters.
1830.Pp
1831Using literal tabs is strongly discouraged because they are very
1832hard to use correctly and
1833.Nm
1834code using them is very hard to read.
1835In particular, a blank character is syntactically significant
1836before and after the literal tab character.
1837If a word precedes or follows the tab without an intervening blank,
1838that word is never interpreted as a macro call, but always output
1839literally.
1840.Pp
1841The tab cell delimiter may only be used within the
1842.Ic \&It
1843line itself; on following lines, only the
1844.Ic \&Ta
1845macro can be used to delimit cells, and portability requires that
1846.Ic \&Ta
1847is called by other macros: some parsers do not recognize it when
1848it appears as the first macro on a line.
1849.Pp
1850Note that quoted strings may span tab-delimited cells on an
1851.Ic \&It
1852line.
1853For example,
1854.Pp
1855.Dl .It \(dqcol1 ,\& <TAB> col2 ,\(dq \&;
1856.Pp
1857will preserve the whitespace before both commas,
1858but not the whitespace before the semicolon.
1859.Pp
1860See also
1861.Ic \&Bl .
1862.Tg Lb
1863.It Ic \&Lb Cm lib Ns Ar name
1864Specify a library.
1865.Pp
1866The
1867.Ar name
1868parameter may be a system library, such as
1869.Cm z
1870or
1871.Cm pam ,
1872in which case a small library description is printed next to the linker
1873invocation; or a custom library, in which case the library name is
1874printed in quotes.
1875This is most commonly used in the
1876.Em SYNOPSIS
1877section as described in
1878.Sx MANUAL STRUCTURE .
1879.Pp
1880Examples:
1881.Dl \&.Lb libz
1882.Dl \&.Lb libmandoc
1883.Tg Li
1884.It Ic \&Li Ar word ...
1885Request a typewriter (literal) font.
1886Deprecated because on terminal output devices, this is usually
1887indistinguishable from normal text.
1888For literal displays, use
1889.Ic \&Ql Pq in-line ,
1890.Ic \&Dl Pq single line ,
1891or
1892.Ic \&Bd Fl literal Pq multi-line
1893instead.
1894.Tg Lk
1895.It Ic \&Lk Ar uri Op Ar display_name
1896Format a hyperlink.
1897.Pp
1898Examples:
1899.Dl \&.Lk https://bsd.lv \(dqThe BSD.lv Project\(dq
1900.Dl \&.Lk https://bsd.lv
1901.Pp
1902See also
1903.Ic \&Mt .
1904.It Ic \&Lp
1905Deprecated synonym for
1906.Ic \&Pp .
1907.Tg Ms
1908.It Ic \&Ms Ar name
1909Display a mathematical symbol.
1910.Pp
1911Examples:
1912.Dl \&.Ms sigma
1913.Dl \&.Ms aleph
1914.Tg Mt
1915.It Ic \&Mt Ar localpart Ns @ Ns Ar domain
1916Format a
1917.Dq mailto:
1918hyperlink.
1919.Pp
1920Examples:
1921.Dl \&.Mt discuss@manpages.bsd.lv
1922.Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
1923.Tg Nd
1924.It Ic \&Nd Ar line
1925A one line description of the manual's content.
1926This is the mandatory last macro of the
1927.Em NAME
1928section and not appropriate for other sections.
1929.Pp
1930Examples:
1931.Dl Pf . Ic \&Nd mdoc language reference
1932.Dl Pf . Ic \&Nd format and display UNIX manuals
1933.Pp
1934The
1935.Ic \&Nd
1936macro technically accepts child macros and terminates with a subsequent
1937.Ic \&Sh
1938invocation.
1939Do not assume this behaviour: some
1940.Xr whatis 1
1941database generators are not smart enough to parse more than the line
1942arguments and will display macros verbatim.
1943.Pp
1944See also
1945.Ic \&Nm .
1946.Tg Nm
1947.It Ic \&Nm Op Ar name
1948The name of the manual page, or \(em in particular in section 1, 6,
1949and 8 pages \(em of an additional command or feature documented in
1950the manual page.
1951When first invoked, the
1952.Ic \&Nm
1953macro expects a single argument, the name of the manual page.
1954Usually, the first invocation happens in the
1955.Em NAME
1956section of the page.
1957The specified name will be remembered and used whenever the macro is
1958called again without arguments later in the page.
1959The
1960.Ic \&Nm
1961macro uses
1962.Sx Block full-implicit
1963semantics when invoked as the first macro on an input line in the
1964.Em SYNOPSIS
1965section; otherwise, it uses ordinary
1966.Sx In-line
1967semantics.
1968.Pp
1969Examples:
1970.Bd -literal -offset indent
1971\&.Sh SYNOPSIS
1972\&.Nm cat
1973\&.Op Fl benstuv
1974\&.Op Ar
1975.Ed
1976.Pp
1977In the
1978.Em SYNOPSIS
1979of section 2, 3 and 9 manual pages, use the
1980.Ic \&Fn
1981macro rather than
1982.Ic \&Nm
1983to mark up the name of the manual page.
1984.Tg No
1985.It Ic \&No Ar word ...
1986Normal text.
1987Closes the scope of any preceding in-line macro.
1988When used after physical formatting macros like
1989.Ic \&Em
1990or
1991.Ic \&Sy ,
1992switches back to the standard font face and weight.
1993Can also be used to embed plain text strings in macro lines
1994using semantic annotation macros.
1995.Pp
1996Examples:
1997.Dl ".Em italic , Sy bold , No and roman"
1998.Bd -literal -offset indent
1999\&.Sm off
2000\&.Cm :C No / Ar pattern No / Ar replacement No /
2001\&.Sm on
2002.Ed
2003.Pp
2004See also
2005.Ic \&Em ,
2006.Ic \&Ql ,
2007and
2008.Ic \&Sy .
2009.Tg Ns
2010.It Ic \&Ns
2011Suppress a space between the output of the preceding macro
2012and the following text or macro.
2013Following invocation, input is interpreted as normal text
2014just like after an
2015.Ic \&No
2016macro.
2017.Pp
2018This has no effect when invoked at the start of a macro line.
2019.Pp
2020Examples:
2021.Dl ".Ar name Ns = Ns Ar value"
2022.Dl ".Cm :M Ns Ar pattern"
2023.Dl ".Fl o Ns Ar output"
2024.Pp
2025See also
2026.Ic \&No
2027and
2028.Ic \&Sm .
2029.Tg Nx
2030.It Ic \&Nx Op Ar version
2031Format the
2032.Nx
2033version provided as an argument, or a default value if
2034no argument is provided.
2035.Pp
2036Examples:
2037.Dl \&.Nx 5.01
2038.Dl \&.Nx
2039.Pp
2040See also
2041.Ic \&At ,
2042.Ic \&Bsx ,
2043.Ic \&Bx ,
2044.Ic \&Dx ,
2045.Ic \&Fx ,
2046and
2047.Ic \&Ox .
2048.It Ic \&Oc
2049Close multi-line
2050.Ic \&Oo
2051context.
2052.It Ic \&Oo Ar block
2053Multi-line version of
2054.Ic \&Op .
2055.Pp
2056Examples:
2057.Bd -literal -offset indent -compact
2058\&.Oo
2059\&.Op Fl flag Ns Ar value
2060\&.Oc
2061.Ed
2062.Tg Op
2063.It Ic \&Op Ar line
2064Optional part of a command line.
2065Prints the argument(s) in brackets.
2066This is most often used in the
2067.Em SYNOPSIS
2068section of section 1 and 8 manual pages.
2069.Pp
2070Examples:
2071.Dl \&.Op \&Fl a \&Ar b
2072.Dl \&.Op \&Ar a | b
2073.Pp
2074See also
2075.Ic \&Oo .
2076.Tg Os
2077.It Ic \&Os Op Ar system Op Ar version
2078Operating system version for display in the page footer.
2079This is the mandatory third macro of
2080any
2081.Nm
2082file.
2083.Pp
2084The optional
2085.Ar system
2086parameter specifies the relevant operating system or environment.
2087It is suggested to leave it unspecified, in which case
2088.Xr mandoc 1
2089uses its
2090.Fl Ios
2091argument or, if that isn't specified either,
2092.Fa sysname
2093and
2094.Fa release
2095as returned by
2096.Xr uname 3 .
2097.Pp
2098Examples:
2099.Dl \&.Os
2100.Dl \&.Os KTH/CSC/TCS
2101.Dl \&.Os BSD 4.3
2102.Pp
2103See also
2104.Ic \&Dd
2105and
2106.Ic \&Dt .
2107.It Ic \&Ot Ar functype
2108This macro is obsolete.
2109Use
2110.Ic \&Ft
2111instead; with
2112.Xr mandoc 1 ,
2113both have the same effect.
2114.Pp
2115Historical
2116.Nm
2117packages described it as
2118.Dq "old function type (FORTRAN)" .
2119.Tg Ox
2120.It Ic \&Ox Op Ar version
2121Format the
2122.Ox
2123version provided as an argument, or a default value
2124if no argument is provided.
2125.Pp
2126Examples:
2127.Dl \&.Ox 4.5
2128.Dl \&.Ox
2129.Pp
2130See also
2131.Ic \&At ,
2132.Ic \&Bsx ,
2133.Ic \&Bx ,
2134.Ic \&Dx ,
2135.Ic \&Fx ,
2136and
2137.Ic \&Nx .
2138.Tg Pa
2139.It Ic \&Pa Ar name ...
2140An absolute or relative file system path, or a file or directory name.
2141If an argument is not provided, the character
2142.Sq \(ti
2143is used as a default.
2144.Pp
2145Examples:
2146.Dl \&.Pa /usr/bin/mandoc
2147.Dl \&.Pa /usr/share/man/man7/mdoc.7
2148.Pp
2149See also
2150.Ic \&Lk .
2151.It Ic \&Pc
2152Close parenthesised context opened by
2153.Ic \&Po .
2154.Tg Pf
2155.It Ic \&Pf Ar prefix macro Op Ar argument ...
2156Removes the space between its argument and the following macro.
2157It is equivalent to:
2158.Pp
2159.D1 Ic \&No Pf \e& Ar prefix Ic \&Ns Ar macro Op Ar argument ...
2160.Pp
2161The
2162.Ar prefix
2163argument is not parsed for macro names or delimiters,
2164but used verbatim as if it were escaped.
2165.Pp
2166Examples:
2167.Dl ".Pf $ Ar variable_name"
2168.Dl ".Pf . Ar macro_name"
2169.Dl ".Pf 0x Ar hex_digits"
2170.Pp
2171See also
2172.Ic \&Ns
2173and
2174.Ic \&Sm .
2175.It Ic \&Po Ar block
2176Multi-line version of
2177.Ic \&Pq .
2178.Tg Pp
2179.It Ic \&Pp
2180Break a paragraph.
2181This will assert vertical space between prior and subsequent macros
2182and/or text.
2183.Pp
2184Paragraph breaks are not needed before or after
2185.Ic \&Sh
2186or
2187.Ic \&Ss
2188macros or before displays
2189.Pq Ic \&Bd Ar line
2190or lists
2191.Pq Ic \&Bl
2192unless the
2193.Fl compact
2194flag is given.
2195.Tg Pq
2196.It Ic \&Pq Ar line
2197Parenthesised enclosure.
2198.Pp
2199See also
2200.Ic \&Po .
2201.It Ic \&Qc
2202Close quoted context opened by
2203.Ic \&Qo .
2204.Tg Ql
2205.It Ic \&Ql Ar line
2206In-line literal display.
2207This can be used for complete command invocations and for multi-word
2208code examples when an indented display is not desired.
2209.Pp
2210See also
2211.Ic \&Dl
2212and
2213.Ic \&Bd
2214.Fl literal .
2215.It Ic \&Qo Ar block
2216Multi-line version of
2217.Ic \&Qq .
2218.Tg Qq
2219.It Ic \&Qq Ar line
2220Encloses its arguments in
2221.Qq typewriter
2222double-quotes.
2223Consider using
2224.Ic \&Dq .
2225.Pp
2226See also
2227.Ic \&Dq ,
2228.Ic \&Sq ,
2229and
2230.Ic \&Qo .
2231.It Ic \&Re
2232Close an
2233.Ic \&Rs
2234block.
2235Does not have any tail arguments.
2236.Tg Rs
2237.It Ic \&Rs
2238Begin a bibliographic
2239.Pq Dq reference
2240block.
2241Does not have any head arguments.
2242The block macro may only contain
2243.Ic \&%A ,
2244.Ic \&%B ,
2245.Ic \&%C ,
2246.Ic \&%D ,
2247.Ic \&%I ,
2248.Ic \&%J ,
2249.Ic \&%N ,
2250.Ic \&%O ,
2251.Ic \&%P ,
2252.Ic \&%Q ,
2253.Ic \&%R ,
2254.Ic \&%T ,
2255.Ic \&%U ,
2256and
2257.Ic \&%V
2258child macros (at least one must be specified).
2259.Pp
2260Examples:
2261.Bd -literal -offset indent -compact
2262\&.Rs
2263\&.%A J. E. Hopcroft
2264\&.%A J. D. Ullman
2265\&.%B Introduction to Automata Theory, Languages, and Computation
2266\&.%I Addison-Wesley
2267\&.%C Reading, Massachusetts
2268\&.%D 1979
2269\&.Re
2270.Ed
2271.Pp
2272If an
2273.Ic \&Rs
2274block is used within a SEE ALSO section, a vertical space is asserted
2275before the rendered output, else the block continues on the current
2276line.
2277.Tg Rv
2278.It Ic \&Rv Fl std Op Ar function ...
2279Insert a standard sentence regarding a function call's return value of 0
2280on success and \-1 on error, with the
2281.Va errno
2282libc global variable set on error.
2283.Pp
2284If
2285.Ar function
2286is not specified, the document's name set by
2287.Ic \&Nm
2288is used.
2289Multiple
2290.Ar function
2291arguments are treated as separate functions.
2292.Pp
2293See also
2294.Ic \&Ex .
2295.It Ic \&Sc
2296Close single-quoted context opened by
2297.Ic \&So .
2298.Tg Sh
2299.It Ic \&Sh Ar TITLE LINE
2300Begin a new section.
2301For a list of conventional manual sections, see
2302.Sx MANUAL STRUCTURE .
2303These sections should be used unless it's absolutely necessary that
2304custom sections be used.
2305.Pp
2306Section names should be unique so that they may be keyed by
2307.Ic \&Sx .
2308Although this macro is parsed, it should not consist of child node or it
2309may not be linked with
2310.Ic \&Sx .
2311.Pp
2312See also
2313.Ic \&Pp ,
2314.Ic \&Ss ,
2315and
2316.Ic \&Sx .
2317.Tg Sm
2318.It Ic \&Sm Op Cm on | off
2319Switches the spacing mode for output generated from macros.
2320.Pp
2321By default, spacing is
2322.Cm on .
2323When switched
2324.Cm off ,
2325no white space is inserted between macro arguments and between the
2326output generated from adjacent macros, but text lines
2327still get normal spacing between words and sentences.
2328.Pp
2329When called without an argument, the
2330.Ic \&Sm
2331macro toggles the spacing mode.
2332Using this is not recommended because it makes the code harder to read.
2333.It Ic \&So Ar block
2334Multi-line version of
2335.Ic \&Sq .
2336.Tg Sq
2337.It Ic \&Sq Ar line
2338Encloses its arguments in
2339.Sq typewriter
2340single-quotes.
2341.Pp
2342See also
2343.Ic \&Dq ,
2344.Ic \&Qq ,
2345and
2346.Ic \&So .
2347.Tg Ss
2348.It Ic \&Ss Ar Title line
2349Begin a new subsection.
2350Unlike with
2351.Ic \&Sh ,
2352there is no convention for the naming of subsections.
2353Except
2354.Em DESCRIPTION ,
2355the conventional sections described in
2356.Sx MANUAL STRUCTURE
2357rarely have subsections.
2358.Pp
2359Sub-section names should be unique so that they may be keyed by
2360.Ic \&Sx .
2361Although this macro is parsed, it should not consist of child node or it
2362may not be linked with
2363.Ic \&Sx .
2364.Pp
2365See also
2366.Ic \&Pp ,
2367.Ic \&Sh ,
2368and
2369.Ic \&Sx .
2370.Tg St
2371.It Ic \&St Fl Ns Ar abbreviation
2372Replace an abbreviation for a standard with the full form.
2373The following standards are recognised.
2374Where multiple lines are given without a blank line in between,
2375they all refer to the same standard, and using the first form
2376is recommended.
2377.Bl -tag -width 1n
2378.It C language standards
2379.Pp
2380.Bl -tag -width "-p1003.1g-2000" -compact
2381.It \-ansiC
2382.St -ansiC
2383.It \-ansiC-89
2384.St -ansiC-89
2385.It \-isoC
2386.St -isoC
2387.It \-isoC-90
2388.St -isoC-90
2389.br
2390The original C standard.
2391.Pp
2392.It \-isoC-amd1
2393.St -isoC-amd1
2394.Pp
2395.It \-isoC-tcor1
2396.St -isoC-tcor1
2397.Pp
2398.It \-isoC-tcor2
2399.St -isoC-tcor2
2400.Pp
2401.It \-isoC-99
2402.St -isoC-99
2403.br
2404The second major version of the C language standard.
2405.Pp
2406.It \-isoC-2011
2407.St -isoC-2011
2408.br
2409The third major version of the C language standard.
2410.El
2411.It POSIX.1 before the Single UNIX Specification
2412.Pp
2413.Bl -tag -width "-p1003.1g-2000" -compact
2414.It \-p1003.1-88
2415.St -p1003.1-88
2416.It \-p1003.1
2417.St -p1003.1
2418.br
2419The original POSIX standard, based on ANSI C.
2420.Pp
2421.It \-p1003.1-90
2422.St -p1003.1-90
2423.It \-iso9945-1-90
2424.St -iso9945-1-90
2425.br
2426The first update of POSIX.1.
2427.Pp
2428.It \-p1003.1b-93
2429.St -p1003.1b-93
2430.It \-p1003.1b
2431.St -p1003.1b
2432.br
2433Real-time extensions.
2434.Pp
2435.It \-p1003.1c-95
2436.St -p1003.1c-95
2437.br
2438POSIX thread interfaces.
2439.Pp
2440.It \-p1003.1i-95
2441.St -p1003.1i-95
2442.br
2443Technical Corrigendum.
2444.Pp
2445.It \-p1003.1-96
2446.St -p1003.1-96
2447.It \-iso9945-1-96
2448.St -iso9945-1-96
2449.br
2450Includes POSIX.1-1990, 1b, 1c, and 1i.
2451.El
2452.It X/Open Portability Guide version 4 and related standards
2453.Pp
2454.Bl -tag -width "-p1003.1g-2000" -compact
2455.It \-xpg3
2456.St -xpg3
2457.br
2458An XPG4 precursor, published in 1989.
2459.Pp
2460.It \-p1003.2
2461.St -p1003.2
2462.It \-p1003.2-92
2463.St -p1003.2-92
2464.It \-iso9945-2-93
2465.St -iso9945-2-93
2466.br
2467An XCU4 precursor.
2468.Pp
2469.It \-p1003.2a-92
2470.St -p1003.2a-92
2471.br
2472Updates to POSIX.2.
2473.Pp
2474.It \-xpg4
2475.St -xpg4
2476.br
2477Based on POSIX.1 and POSIX.2, published in 1992.
2478.El
2479.It Single UNIX Specification version 1 and related standards
2480.Pp
2481.Bl -tag -width "-p1003.1g-2000" -compact
2482.It \-susv1
2483.St -susv1
2484.It \-xpg4.2
2485.St -xpg4.2
2486.br
2487This standard was published in 1994.
2488It was used as the basis for UNIX 95 certification.
2489The following three refer to parts of it.
2490.Pp
2491.It \-xsh4.2
2492.St -xsh4.2
2493.Pp
2494.It \-xcurses4.2
2495.St -xcurses4.2
2496.Pp
2497.It \-p1003.1g-2000
2498.St -p1003.1g-2000
2499.br
2500Networking APIs, including sockets.
2501.Pp
2502.It \-svid4
2503.St -svid4 ,
2504.br
2505Published in 1995.
2506.El
2507.It Single UNIX Specification version 2 and related standards
2508.Pp
2509.Bl -tag -width "-p1003.1g-2000" -compact
2510.It \-susv2
2511.St -susv2
2512This Standard was published in 1997
2513and is also called X/Open Portability Guide version 5.
2514It was used as the basis for UNIX 98 certification.
2515The following refer to parts of it.
2516.Pp
2517.It \-xbd5
2518.St -xbd5
2519.Pp
2520.It \-xsh5
2521.St -xsh5
2522.Pp
2523.It \-xcu5
2524.St -xcu5
2525.Pp
2526.It \-xns5
2527.St -xns5
2528.It \-xns5.2
2529.St -xns5.2
2530.El
2531.It Single UNIX Specification version 3
2532.Pp
2533.Bl -tag -width "-p1003.1-2001" -compact
2534.It \-p1003.1-2001
2535.St -p1003.1-2001
2536.It \-susv3
2537.St -susv3
2538.br
2539This standard is based on C99, SUSv2, POSIX.1-1996, 1d, and 1j.
2540It is also called X/Open Portability Guide version 6.
2541It is used as the basis for UNIX 03 certification.
2542.Pp
2543.It \-p1003.1-2004
2544.St -p1003.1-2004
2545.br
2546The second and last Technical Corrigendum.
2547.El
2548.It Single UNIX Specification version 4
2549.Pp
2550.Bl -tag -width "-p1003.1g-2000" -compact
2551.It \-p1003.1-2008
2552.St -p1003.1-2008
2553.It \-susv4
2554.St -susv4
2555.br
2556This standard is also called
2557X/Open Portability Guide version 7.
2558.El
2559.It Other standards
2560.Pp
2561.Bl -tag -width "-p1003.1g-2000" -compact
2562.It \-ieee754
2563.St -ieee754
2564.br
2565Floating-point arithmetic.
2566.Pp
2567.It \-iso8601
2568.St -iso8601
2569.br
2570Representation of dates and times, published in 1988.
2571.Pp
2572.It \-iso8802-3
2573.St -iso8802-3
2574.br
2575Ethernet local area networks.
2576.Pp
2577.It \-ieee1275-94
2578.St -ieee1275-94
2579.El
2580.El
2581.Tg Sx
2582.It Ic \&Sx Ar Title line
2583Reference a section or subsection in the same manual page.
2584The referenced section or subsection name must be identical to the
2585enclosed argument, including whitespace.
2586.Pp
2587Examples:
2588.Dl \&.Sx MANUAL STRUCTURE
2589.Pp
2590See also
2591.Ic \&Sh
2592and
2593.Ic \&Ss .
2594.Tg Sy
2595.It Ic \&Sy Ar word ...
2596Request a boldface font.
2597.Pp
2598This is most often used to indicate importance or seriousness (not to be
2599confused with stress emphasis, see
2600.Ic \&Em ) .
2601When none of the semantic macros fit, it is also adequate for syntax
2602elements that have to be given or that appear verbatim.
2603.Pp
2604Examples:
2605.Bd -literal -compact -offset indent
2606\&.Sy Warning :
2607If
2608\&.Sy s
2609appears in the owner permissions, set-user-ID mode is set.
2610This utility replaces the former
2611\&.Sy dumpdir
2612program.
2613.Ed
2614.Pp
2615See also
2616.Ic \&Em ,
2617.Ic \&No ,
2618and
2619.Ic \&Ql .
2620.Tg Ta
2621.It Ic \&Ta
2622Table cell separator in
2623.Ic \&Bl Fl column
2624lists; can only be used below
2625.Ic \&It .
2626.Tg Tg
2627.It Ic \&Tg Op Ar term
2628Announce that the next input line starts a definition of the
2629.Ar term .
2630This macro must appear alone on its own input line.
2631The argument defaults to the first argument of the first macro
2632on the next line.
2633The argument may not contain whitespace characters, not even when it is quoted.
2634This macro is a
2635.Xr mandoc 1
2636extension and is typically ignored by other formatters.
2637.Pp
2638When viewing terminal output with
2639.Xr less 1 ,
2640the interactive
2641.Ic :t
2642command can be used to go to the definition of the
2643.Ar term
2644as described for the
2645.Ev MANPAGER
2646variable in
2647.Xr man 1 ;
2648when producing HTML output, a fragment identifier
2649.Pq Ic id No attribute
2650is generated, to be used for deep linking to this place of the document.
2651.Pp
2652In most cases, adding a
2653.Ic \&Tg
2654macro would be redundant because
2655.Xr mandoc 1
2656is able to automatically tag most definitions.
2657This macro is intended for cases where automatic tagging of a
2658.Ar term
2659is unsatisfactory, for example if a definition is not tagged
2660automatically (false negative) or if places are tagged that do
2661not define the
2662.Ar term
2663(false positives).
2664When there is at least one
2665.Ic \&Tg
2666macro for a
2667.Ar term ,
2668no other places are automatically marked as definitions of that
2669.Ar term .
2670.It Ic \&Tn Ar word ...
2671Supported only for compatibility, do not use this in new manuals.
2672Even though the macro name
2673.Pq Dq tradename
2674suggests a semantic function, historic usage is inconsistent, mostly
2675using it as a presentation-level macro to request a small caps font.
2676.It Ic \&Ud
2677Supported only for compatibility, do not use this in new manuals.
2678Prints out
2679.Dq currently under development.
2680.It Ic \&Ux
2681Supported only for compatibility, do not use this in new manuals.
2682Prints out
2683.Dq Ux .
2684.Tg Va
2685.It Ic \&Va Oo Ar type Oc Ar identifier ...
2686A variable name.
2687.Pp
2688Examples:
2689.Dl \&.Va foo
2690.Dl \&.Va const char *bar ;
2691.Pp
2692For function arguments and parameters, use
2693.Ic \&Fa
2694instead.
2695For declarations of global variables in the
2696.Em SYNOPSIS
2697section, use
2698.Ic \&Vt .
2699.Tg Vt
2700.It Ic \&Vt Ar type Op Ar identifier
2701A variable type.
2702.Pp
2703This is also used for indicating global variables in the
2704.Em SYNOPSIS
2705section, in which case a variable name is also specified.
2706Note that it accepts
2707.Sx Block partial-implicit
2708syntax when invoked as the first macro on an input line in the
2709.Em SYNOPSIS
2710section, else it accepts ordinary
2711.Sx In-line
2712syntax.
2713In the former case, this macro starts a new output line,
2714and a blank line is inserted in front if there is a preceding
2715function definition or include directive.
2716.Pp
2717Examples:
2718.Dl \&.Vt unsigned char
2719.Dl \&.Vt extern const char * const sys_signame[] \&;
2720.Pp
2721For parameters in function prototypes, use
2722.Ic \&Fa
2723instead, for function return types
2724.Ic \&Ft ,
2725and for variable names outside the
2726.Em SYNOPSIS
2727section
2728.Ic \&Va ,
2729even when including a type with the name.
2730See also
2731.Sx MANUAL STRUCTURE .
2732.It Ic \&Xc
2733Close a scope opened by
2734.Ic \&Xo .
2735.It Ic \&Xo Ar block
2736Extend the header of an
2737.Ic \&It
2738macro or the body of a partial-implicit block macro
2739beyond the end of the input line.
2740This macro originally existed to work around the 9-argument limit
2741of historic
2742.Xr roff 7 .
2743.Tg Xr
2744.It Ic \&Xr Ar name section
2745Link to another manual
2746.Pq Qq cross-reference .
2747.Pp
2748Cross reference the
2749.Ar name
2750and
2751.Ar section
2752number of another man page.
2753.Pp
2754Examples:
2755.Dl \&.Xr mandoc 1
2756.Dl \&.Xr mandoc 1 \&;
2757.Dl \&.Xr mandoc 1 \&Ns s behaviour
2758.El
2759.Sh MACRO SYNTAX
2760The syntax of a macro depends on its classification.
2761In this section,
2762.Sq \-arg
2763refers to macro arguments, which may be followed by zero or more
2764.Sq parm
2765parameters;
2766.Sq \&Yo
2767opens the scope of a macro; and if specified,
2768.Sq \&Yc
2769closes it out.
2770.Pp
2771The
2772.Em Callable
2773column indicates that the macro may also be called by passing its name
2774as an argument to another macro.
2775For example,
2776.Sq \&.Op \&Fl O \&Ar file
2777produces
2778.Sq Op Fl O Ar file .
2779To prevent a macro call and render the macro name literally,
2780escape it by prepending a zero-width space,
2781.Sq \e& .
2782For example,
2783.Sq \&Op \e&Fl O
2784produces
2785.Sq Op \&Fl O .
2786If a macro is not callable but its name appears as an argument
2787to another macro, it is interpreted as opaque text.
2788For example,
2789.Sq \&.Fl \&Sh
2790produces
2791.Sq Fl \&Sh .
2792.Pp
2793The
2794.Em Parsed
2795column indicates whether the macro may call other macros by receiving
2796their names as arguments.
2797If a macro is not parsed but the name of another macro appears
2798as an argument, it is interpreted as opaque text.
2799.Pp
2800The
2801.Em Scope
2802column, if applicable, describes closure rules.
2803.Ss Block full-explicit
2804Multi-line scope closed by an explicit closing macro.
2805All macros contains bodies; only
2806.Ic \&Bf
2807and
2808.Pq optionally
2809.Ic \&Bl
2810contain a head.
2811.Bd -literal -offset indent
2812\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
2813\(lBbody...\(rB
2814\&.Yc
2815.Ed
2816.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXX" -offset indent
2817.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
2818.It Ic \&Bd  Ta    \&No     Ta    \&No     Ta    closed by Ic \&Ed
2819.It Ic \&Bf  Ta    \&No     Ta    \&No     Ta    closed by Ic \&Ef
2820.It Ic \&Bk  Ta    \&No     Ta    \&No     Ta    closed by Ic \&Ek
2821.It Ic \&Bl  Ta    \&No     Ta    \&No     Ta    closed by Ic \&El
2822.It Ic \&Ed  Ta    \&No     Ta    \&No     Ta    opened by Ic \&Bd
2823.It Ic \&Ef  Ta    \&No     Ta    \&No     Ta    opened by Ic \&Bf
2824.It Ic \&Ek  Ta    \&No     Ta    \&No     Ta    opened by Ic \&Bk
2825.It Ic \&El  Ta    \&No     Ta    \&No     Ta    opened by Ic \&Bl
2826.El
2827.Ss Block full-implicit
2828Multi-line scope closed by end-of-file or implicitly by another macro.
2829All macros have bodies; some
2830.Po
2831.Ic \&It Fl bullet ,
2832.Fl hyphen ,
2833.Fl dash ,
2834.Fl enum ,
2835.Fl item
2836.Pc
2837don't have heads; only one
2838.Po
2839.Ic \&It
2840in
2841.Ic \&Bl Fl column
2842.Pc
2843has multiple heads.
2844.Bd -literal -offset indent
2845\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead... \(lBTa head...\(rB\(rB
2846\(lBbody...\(rB
2847.Ed
2848.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXXXXXXXXX" -offset indent
2849.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
2850.It Ic \&It Ta \&No Ta Yes  Ta closed by Ic \&It , Ic \&El
2851.It Ic \&Nd Ta \&No Ta \&No Ta closed by Ic \&Sh
2852.It Ic \&Nm Ta \&No Ta Yes  Ta closed by Ic \&Nm , Ic \&Sh , Ic \&Ss
2853.It Ic \&Sh Ta \&No Ta Yes  Ta closed by Ic \&Sh
2854.It Ic \&Ss Ta \&No Ta Yes  Ta closed by Ic \&Sh , Ic \&Ss
2855.El
2856.Pp
2857Note that the
2858.Ic \&Nm
2859macro is a
2860.Sx Block full-implicit
2861macro only when invoked as the first macro
2862in a
2863.Em SYNOPSIS
2864section line, else it is
2865.Sx In-line .
2866.Ss Block partial-explicit
2867Like block full-explicit, but also with single-line scope.
2868Each has at least a body and, in limited circumstances, a head
2869.Po
2870.Ic \&Fo ,
2871.Ic \&Eo
2872.Pc
2873and/or tail
2874.Pq Ic \&Ec .
2875.Bd -literal -offset indent
2876\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
2877\(lBbody...\(rB
2878\&.Yc \(lBtail...\(rB
2879
2880\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB \
2881\(lBbody...\(rB \&Yc \(lBtail...\(rB
2882.Ed
2883.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -offset indent
2884.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
2885.It Ic \&Ac  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Ao
2886.It Ic \&Ao  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Ac
2887.It Ic \&Bc  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Bo
2888.It Ic \&Bo  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Bc
2889.It Ic \&Brc Ta    Yes      Ta    Yes      Ta    opened by Ic \&Bro
2890.It Ic \&Bro Ta    Yes      Ta    Yes      Ta    closed by Ic \&Brc
2891.It Ic \&Dc  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Do
2892.It Ic \&Do  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Dc
2893.It Ic \&Ec  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Eo
2894.It Ic \&Eo  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Ec
2895.It Ic \&Fc  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Fo
2896.It Ic \&Fo  Ta    \&No     Ta    \&No     Ta    closed by Ic \&Fc
2897.It Ic \&Oc  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Oo
2898.It Ic \&Oo  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Oc
2899.It Ic \&Pc  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Po
2900.It Ic \&Po  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Pc
2901.It Ic \&Qc  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Oo
2902.It Ic \&Qo  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Oc
2903.It Ic \&Re  Ta    \&No     Ta    \&No     Ta    opened by Ic \&Rs
2904.It Ic \&Rs  Ta    \&No     Ta    \&No     Ta    closed by Ic \&Re
2905.It Ic \&Sc  Ta    Yes      Ta    Yes      Ta    opened by Ic \&So
2906.It Ic \&So  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Sc
2907.It Ic \&Xc  Ta    Yes      Ta    Yes      Ta    opened by Ic \&Xo
2908.It Ic \&Xo  Ta    Yes      Ta    Yes      Ta    closed by Ic \&Xc
2909.El
2910.Ss Block partial-implicit
2911Like block full-implicit, but with single-line scope closed by the
2912end of the line.
2913.Bd -literal -offset indent
2914\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
2915.Ed
2916.Bl -column "MacroX" "CallableX" "ParsedX" -offset indent
2917.It Em Macro Ta Em Callable Ta Em Parsed
2918.It Ic \&Aq  Ta    Yes      Ta    Yes
2919.It Ic \&Bq  Ta    Yes      Ta    Yes
2920.It Ic \&Brq Ta    Yes      Ta    Yes
2921.It Ic \&D1  Ta    \&No     Ta    \&Yes
2922.It Ic \&Dl  Ta    \&No     Ta    Yes
2923.It Ic \&Dq  Ta    Yes      Ta    Yes
2924.It Ic \&En  Ta    Yes      Ta    Yes
2925.It Ic \&Op  Ta    Yes      Ta    Yes
2926.It Ic \&Pq  Ta    Yes      Ta    Yes
2927.It Ic \&Ql  Ta    Yes      Ta    Yes
2928.It Ic \&Qq  Ta    Yes      Ta    Yes
2929.It Ic \&Sq  Ta    Yes      Ta    Yes
2930.It Ic \&Vt  Ta    Yes      Ta    Yes
2931.El
2932.Pp
2933Note that the
2934.Ic \&Vt
2935macro is a
2936.Sx Block partial-implicit
2937only when invoked as the first macro
2938in a
2939.Em SYNOPSIS
2940section line, else it is
2941.Sx In-line .
2942.Ss Special block macro
2943The
2944.Ic \&Ta
2945macro can only be used below
2946.Ic \&It
2947in
2948.Ic \&Bl Fl column
2949lists.
2950It delimits blocks representing table cells;
2951these blocks have bodies, but no heads.
2952.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -offset indent
2953.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
2954.It Ic \&Ta  Ta    Yes      Ta    Yes    Ta closed by Ic \&Ta , Ic \&It
2955.El
2956.Ss In-line
2957Closed by the end of the line, fixed argument lengths,
2958and/or subsequent macros.
2959In-line macros have only text children.
2960If a number (or inequality) of arguments is
2961.Pq n ,
2962then the macro accepts an arbitrary number of arguments.
2963.Bd -literal -offset indent
2964\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lBres...\(rB
2965
2966\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
2967
2968\&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
2969.Ed
2970.Bl -column "MacroX" "CallableX" "ParsedX" "Arguments" -offset indent
2971.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Arguments
2972.It Ic \&%A  Ta    \&No     Ta    \&No     Ta    >0
2973.It Ic \&%B  Ta    \&No     Ta    \&No     Ta    >0
2974.It Ic \&%C  Ta    \&No     Ta    \&No     Ta    >0
2975.It Ic \&%D  Ta    \&No     Ta    \&No     Ta    >0
2976.It Ic \&%I  Ta    \&No     Ta    \&No     Ta    >0
2977.It Ic \&%J  Ta    \&No     Ta    \&No     Ta    >0
2978.It Ic \&%N  Ta    \&No     Ta    \&No     Ta    >0
2979.It Ic \&%O  Ta    \&No     Ta    \&No     Ta    >0
2980.It Ic \&%P  Ta    \&No     Ta    \&No     Ta    >0
2981.It Ic \&%Q  Ta    \&No     Ta    \&No     Ta    >0
2982.It Ic \&%R  Ta    \&No     Ta    \&No     Ta    >0
2983.It Ic \&%T  Ta    \&No     Ta    \&No     Ta    >0
2984.It Ic \&%U  Ta    \&No     Ta    \&No     Ta    >0
2985.It Ic \&%V  Ta    \&No     Ta    \&No     Ta    >0
2986.It Ic \&Ad  Ta    Yes      Ta    Yes      Ta    >0
2987.It Ic \&An  Ta    Yes      Ta    Yes      Ta    >0
2988.It Ic \&Ap  Ta    Yes      Ta    Yes      Ta    0
2989.It Ic \&Ar  Ta    Yes      Ta    Yes      Ta    n
2990.It Ic \&At  Ta    Yes      Ta    Yes      Ta    1
2991.It Ic \&Bsx Ta    Yes      Ta    Yes      Ta    n
2992.It Ic \&Bt  Ta    \&No     Ta    \&No     Ta    0
2993.It Ic \&Bx  Ta    Yes      Ta    Yes      Ta    n
2994.It Ic \&Cd  Ta    Yes      Ta    Yes      Ta    >0
2995.It Ic \&Cm  Ta    Yes      Ta    Yes      Ta    >0
2996.It Ic \&Db  Ta    \&No     Ta    \&No     Ta    1
2997.It Ic \&Dd  Ta    \&No     Ta    \&No     Ta    n
2998.It Ic \&Dt  Ta    \&No     Ta    \&No     Ta    n
2999.It Ic \&Dv  Ta    Yes      Ta    Yes      Ta    >0
3000.It Ic \&Dx  Ta    Yes      Ta    Yes      Ta    n
3001.It Ic \&Em  Ta    Yes      Ta    Yes      Ta    >0
3002.It Ic \&Er  Ta    Yes      Ta    Yes      Ta    >0
3003.It Ic \&Es  Ta    Yes      Ta    Yes      Ta    2
3004.It Ic \&Ev  Ta    Yes      Ta    Yes      Ta    >0
3005.It Ic \&Ex  Ta    \&No     Ta    \&No     Ta    n
3006.It Ic \&Fa  Ta    Yes      Ta    Yes      Ta    >0
3007.It Ic \&Fd  Ta    \&No     Ta    \&No     Ta    >0
3008.It Ic \&Fl  Ta    Yes      Ta    Yes      Ta    n
3009.It Ic \&Fn  Ta    Yes      Ta    Yes      Ta    >0
3010.It Ic \&Fr  Ta    Yes      Ta    Yes      Ta    >0
3011.It Ic \&Ft  Ta    Yes      Ta    Yes      Ta    >0
3012.It Ic \&Fx  Ta    Yes      Ta    Yes      Ta    n
3013.It Ic \&Hf  Ta    \&No     Ta    \&No     Ta    n
3014.It Ic \&Ic  Ta    Yes      Ta    Yes      Ta    >0
3015.It Ic \&In  Ta    \&No     Ta    \&No     Ta    1
3016.It Ic \&Lb  Ta    \&No     Ta    \&No     Ta    1
3017.It Ic \&Li  Ta    Yes      Ta    Yes      Ta    >0
3018.It Ic \&Lk  Ta    Yes      Ta    Yes      Ta    >0
3019.It Ic \&Lp  Ta    \&No     Ta    \&No     Ta    0
3020.It Ic \&Ms  Ta    Yes      Ta    Yes      Ta    >0
3021.It Ic \&Mt  Ta    Yes      Ta    Yes      Ta    >0
3022.It Ic \&Nm  Ta    Yes      Ta    Yes      Ta    n
3023.It Ic \&No  Ta    Yes      Ta    Yes      Ta    >0
3024.It Ic \&Ns  Ta    Yes      Ta    Yes      Ta    0
3025.It Ic \&Nx  Ta    Yes      Ta    Yes      Ta    n
3026.It Ic \&Os  Ta    \&No     Ta    \&No     Ta    n
3027.It Ic \&Ot  Ta    Yes      Ta    Yes      Ta    >0
3028.It Ic \&Ox  Ta    Yes      Ta    Yes      Ta    n
3029.It Ic \&Pa  Ta    Yes      Ta    Yes      Ta    n
3030.It Ic \&Pf  Ta    Yes      Ta    Yes      Ta    1
3031.It Ic \&Pp  Ta    \&No     Ta    \&No     Ta    0
3032.It Ic \&Rv  Ta    \&No     Ta    \&No     Ta    n
3033.It Ic \&Sm  Ta    \&No     Ta    \&No     Ta    <2
3034.It Ic \&St  Ta    \&No     Ta    Yes      Ta    1
3035.It Ic \&Sx  Ta    Yes      Ta    Yes      Ta    >0
3036.It Ic \&Sy  Ta    Yes      Ta    Yes      Ta    >0
3037.It Ic \&Tg  Ta    \&No     Ta    \&No     Ta    <2
3038.It Ic \&Tn  Ta    Yes      Ta    Yes      Ta    >0
3039.It Ic \&Ud  Ta    \&No     Ta    \&No     Ta    0
3040.It Ic \&Ux  Ta    Yes      Ta    Yes      Ta    n
3041.It Ic \&Va  Ta    Yes      Ta    Yes      Ta    n
3042.It Ic \&Vt  Ta    Yes      Ta    Yes      Ta    >0
3043.It Ic \&Xr  Ta    Yes      Ta    Yes      Ta    2
3044.El
3045.Ss Delimiters
3046When a macro argument consists of one single input character
3047considered as a delimiter, the argument gets special handling.
3048This does not apply when delimiters appear in arguments containing
3049more than one character.
3050Consequently, to prevent special handling and just handle it
3051like any other argument, a delimiter can be escaped by prepending
3052a zero-width space
3053.Pq Sq \e& .
3054In text lines, delimiters never need escaping, but may be used
3055as normal punctuation.
3056.Pp
3057For many macros, when the leading arguments are opening delimiters,
3058these delimiters are put before the macro scope,
3059and when the trailing arguments are closing delimiters,
3060these delimiters are put after the macro scope.
3061Spacing is suppressed after opening delimiters
3062and before closing delimiters.
3063For example,
3064.Pp
3065.D1 Pf \. \&Aq "( [ word ] ) ."
3066.Pp
3067renders as:
3068.Pp
3069.D1 Aq ( [ word ] ) .
3070.Pp
3071Opening delimiters are:
3072.Pp
3073.Bl -tag -width Ds -offset indent -compact
3074.It \&(
3075left parenthesis
3076.It \&[
3077left bracket
3078.El
3079.Pp
3080Closing delimiters are:
3081.Pp
3082.Bl -tag -width Ds -offset indent -compact
3083.It \&.
3084period
3085.It \&,
3086comma
3087.It \&:
3088colon
3089.It \&;
3090semicolon
3091.It \&)
3092right parenthesis
3093.It \&]
3094right bracket
3095.It \&?
3096question mark
3097.It \&!
3098exclamation mark
3099.El
3100.Pp
3101Note that even a period preceded by a backslash
3102.Pq Sq \e.\&
3103gets this special handling; use
3104.Sq \e&.\&
3105to prevent that.
3106.Pp
3107Many in-line macros interrupt their scope when they encounter
3108delimiters, and resume their scope when more arguments follow that
3109are not delimiters.
3110For example,
3111.Pp
3112.D1 Pf \. \&Fl "a ( b | c \e*(Ba d ) e"
3113.Pp
3114renders as:
3115.Pp
3116.D1 Fl a ( b | c \*(Ba d ) e
3117.Pp
3118This applies to both opening and closing delimiters,
3119and also to the middle delimiter, which does not suppress spacing:
3120.Pp
3121.Bl -tag -width Ds -offset indent -compact
3122.It \&|
3123vertical bar
3124.El
3125.Pp
3126As a special case, the predefined string \e*(Ba is handled and rendered
3127in the same way as a plain
3128.Sq \&|
3129character.
3130Using this predefined string is not recommended in new manuals.
3131.Pp
3132Appending a zero-width space
3133.Pq Sq \e&
3134to the end of an input line is also useful to prevent the interpretation
3135of a trailing period, exclamation or question mark as the end of a
3136sentence, for example when an abbreviation happens to occur
3137at the end of a text or macro input line.
3138.Ss Font handling
3139In
3140.Nm
3141documents, usage of semantic markup is recommended in order to have
3142proper fonts automatically selected; only when no fitting semantic markup
3143is available, consider falling back to
3144.Sx Physical markup
3145macros.
3146Whenever any
3147.Nm
3148macro switches the
3149.Xr roff 7
3150font mode, it will automatically restore the previous font when exiting
3151its scope.
3152Manually switching the font using the
3153.Xr roff 7
3154.Ql \ef
3155font escape sequences is never required.
3156.Sh COMPATIBILITY
3157This section provides an incomplete list of compatibility issues
3158between mandoc and GNU troff
3159.Pq Qq groff .
3160.Pp
3161The following problematic behaviour is found in groff:
3162.Pp
3163.Bl -dash -compact
3164.It
3165.Ic \&Pa
3166does not format its arguments when used in the FILES section under
3167certain list types.
3168.It
3169.Ic \&Ta
3170can only be called by other macros, but not at the beginning of a line.
3171.It
3172.Sq \ef
3173.Pq font face
3174and
3175.Sq \eF
3176.Pq font family face
3177.Sx Text Decoration
3178escapes behave irregularly when specified within line-macro scopes.
3179.It
3180Negative scaling units return to prior lines.
3181Instead, mandoc truncates them to zero.
3182.El
3183.Pp
3184The following features are unimplemented in mandoc:
3185.Pp
3186.Bl -dash -compact
3187.It
3188.Ic \&Bd Fl file Ar file
3189is unsupported for security reasons.
3190.It
3191.Ic \&Bd
3192.Fl filled
3193does not adjust the right margin, but is an alias for
3194.Ic \&Bd
3195.Fl ragged .
3196.It
3197.Ic \&Bd
3198.Fl literal
3199does not use a literal font, but is an alias for
3200.Ic \&Bd
3201.Fl unfilled .
3202.It
3203.Ic \&Bd
3204.Fl offset Cm center
3205and
3206.Fl offset Cm right
3207don't work.
3208Groff does not implement centered and flush-right rendering either,
3209but produces large indentations.
3210.El
3211.Sh SEE ALSO
3212.Xr man 1 ,
3213.Xr mandoc 1 ,
3214.Xr eqn 7 ,
3215.Xr man 7 ,
3216.Xr mandoc_char 7 ,
3217.Xr roff 7 ,
3218.Xr tbl 7
3219.Pp
3220The web page
3221.Lk https://mandoc.bsd.lv/mdoc/ "extended documentation for the mdoc language"
3222provides a few tutorial-style pages for beginners, an extensive style
3223guide for advanced authors, and an alphabetic index helping to choose
3224the best macros for various kinds of content.
3225.Pp
3226The manual page
3227.Lk https://man.voidlinux.org/groff_mdoc "groff_mdoc(7)"
3228contained in the
3229.Dq groff
3230package documents exactly the same language in a somewhat different style.
3231.Sh HISTORY
3232The
3233.Nm
3234language first appeared as a troff macro package in
3235.Bx 4.4 .
3236It was later significantly updated by Werner Lemberg and Ruslan Ermilov
3237in groff-1.17.
3238The standalone implementation that is part of the
3239.Xr mandoc 1
3240utility written by Kristaps Dzonsons appeared in
3241.Ox 4.6 .
3242.Sh AUTHORS
3243The
3244.Nm
3245reference was written by
3246.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .
3247