MDOC(7) NetBSD Miscellaneous Information Manual MDOC(7)

NAME

mdocmdoc language reference

DESCRIPTION

The mdoc language is used to format BSD UNIX manuals. This reference document describes its syntax, structure, and usage. The reference implementation is mandoc(1); the COMPATIBILITY section describes compatibility with other troff -mdoc implementations.

An mdoc document follows simple rules: lines beginning with the control character ‘'. are parsed for macros. Other lines are interpreted within the scope of prior macros:

.Sh Macro lines change control state. 
Other lines are interpreted within the current state.

LANGUAGE SYNTAX

mdoc documents may contain only graphable 7-bit ASCII characters, the space character, and, in certain circumstances, the tab character.

If the first character of a line is a space, that line is printed with a leading newline.

Comments

Text following a ‘\"', whether in a macro or free-form text line, is ignored to the end of line. A macro line with only a control character and comment escape, ‘.\"', is also ignored. Macro lines with only a control character and optional whitespace are stripped from input.

Reserved Terms

Within a macro line, the following terms are reserved:

.
(period)
\.
(escaped period)
,
(comma)
:
(colon)
;
(semicolon)
(
(left-parenthesis)
)
(right-parenthesis)
[
(left-bracket)
]
(right-bracket)
?
(question)
!
(exclamation)
|
(vertical bar)
\*(Ba
(reserved-word vertical bar)

Use of reserved terms is described in MACRO SYNTAX. For general use in macro lines, these can be escaped with a non-breaking space (‘\&').

Special Characters

Special characters may occur in both macro and free-form lines. Sequences begin with the escape character ‘\' followed by either an open-parenthesis ‘(' for two-character sequences; an open-bracket ‘[' for n-character sequences (terminated at a close-bracket ‘]'); or a single one character sequence. See mandoc_char(7) for a complete list. Examples include ‘\(em' (em-dash) and ‘\e' (back-slash).

Text Decoration

Terms may be text-decorated using the ‘\f' escape followed by an indicator: B (bold), I (italic), R (Roman), or P (revert to previous mode):

\fBbold\fR \fIitalic\fP

A numerical representation 3, 2, or 1 (bold, italic, and Roman, respectively) may be used instead. A text decoration is valid within the current font scope only: if a macro opens a font scope alongside its own scope, such as Bf Sy, in-scope invocations of ‘\f' are only valid within the font scope of the macro. If ‘\f' is specified outside of any font scope, such as in unenclosed, free-form text, it will affect the remainder of the document.

Note this form is not recommended for mdoc, which encourages semantic annotation.

Predefined Strings

Historically, troff also defined a set of package-specific “predefined strings”, which, like Special Characters, mark special output characters and strings by way of input codes. Predefined strings are escaped with the slash-asterisk, ‘\*': single-character ‘\*X', two-character ‘\*(XX', and N-character ‘\*[N]'. See mandoc_char(7) for a complete list. Examples include ‘\*(Am' (ampersand) and ‘\*(Ba' (vertical bar).

Whitespace

Whitespace consists of the space character. In free-form lines, whitespace is preserved within a line; unescaped trailing spaces are stripped from input (unless in a literal context). Blank free-form lines, which may include whitespace, are only permitted within literal contexts.

In macro lines, whitespace delimits arguments and is discarded. If arguments are quoted, whitespace within the quotes is retained.

Quotation

Macro arguments may be quoted with double-quotes to group space-delimited terms or to retain blocks of whitespace. A quoted argument begins with a double-quote preceded by whitespace. The next double-quote not pairwise adjacent to another double-quote terminates the literal, regardless of surrounding whitespace.

Note that any quoted text, even if it would cause a macro invocation when unquoted, is considered literal text. Thus, the following produces ‘[Fl a]':

.Op "Fl a"

In free-form mode, quotes are regarded as opaque text.

Scaling Widths

Many macros support scaled widths for their arguments, such as stipulating a two-inch list indentation with the following:

.Bl -tag -width 2i

The syntax for scaled widths is ‘[+-]?[0-9]*.[0-9]*[:unit:]', where a decimal must be preceded or proceeded by at least one digit. Negative numbers, while accepted, are truncated to zero. The following scaling units are accepted:

c
centimetre
i
inch
P
pica (~1/6 inch)
p
point (~1/72 inch)
f
synonym for ‘u'
v
default vertical span
m
width of rendered ‘m' (em) character
n
width of rendered ‘n' (en) character
u
default horizontal span
M
mini-em (~1/100 em)

Using anything other than ‘m', ‘n', ‘u', or ‘v' is necessarily non-portable across output media. See COMPATIBILITY.

Sentence Spacing

When composing a manual, make sure that sentences end at the end of a line. By doing so, front-ends will be able to apply the proper amount of spacing after the end of sentence (unescaped) period, exclamation mark, or question mark followed by zero or more non-sentence closing delimiters (‘)', ‘]', ‘'', ‘"').

The proper spacing is also intelligently preserved if a sentence ends at the boundary of a macro line. For example:

Xr mandoc 1.
Fl T Ns Cm ascii.

MANUAL STRUCTURE

A well-formed mdoc document consists of a document prologue followed by one or more sections.

The prologue, which consists of the Dd, Dt, and Os macros in that order, is required for every document.

The first section (sections are denoted by Sh) must be the NAME section, consisting of at least one Nm followed by Nd.

Following that, convention dictates specifying at least the SYNOPSIS and DESCRIPTION sections, although this varies between manual sections.

The following is a well-formed skeleton mdoc file:

.Dd $Mdocdate$ 
.Dt mdoc 7 
.Os 
.Sh NAME 
.Nm foo 
.Nd a description goes here 
.\" .Sh LIBRARY 
.\" For sections 2, 3, & 9 only. 
.\" Not used in OpenBSD. 
.Sh SYNOPSIS 
.Nm foo 
.Op Fl options 
.Ar 
.Sh DESCRIPTION 
The 
.Nm 
utility processes files ... 
.\" .Sh IMPLEMENTATION NOTES 
.\" Not used in OpenBSD. 
.\" .Sh RETURN VALUES 
.\" For sections 2, 3, & 9 only. 
.\" .Sh ENVIRONMENT 
.\" For sections 1, 6, 7, & 8 only. 
.\" .Sh FILES 
.\" .Sh EXIT STATUS 
.\" For sections 1, 6, & 8 only. 
.\" .Sh EXAMPLES 
.\" .Sh DIAGNOSTICS 
.\" For sections 1, 4, 6, 7, & 8 only. 
.\" .Sh ERRORS 
.\" For sections 2, 3, & 9 only. 
.\" .Sh SEE ALSO 
.\" .Xr foobar 1 
.\" .Sh STANDARDS 
.\" .Sh HISTORY 
.\" .Sh AUTHORS 
.\" .Sh CAVEATS 
.\" .Sh BUGS 
.\" .Sh SECURITY CONSIDERATIONS 
.\" Not used in OpenBSD.

The sections in an mdoc document are conventionally ordered as they appear above. Sections should be composed as follows:

NAME
The name(s) and a one line description of the documented material. The syntax for this as follows:

.Nm name0 , 
.Nm name1 , 
.Nm name2 
.Nd a one line description

The Nm macro(s) must precede the Nd macro.

See Nm and Nd.

LIBRARY
The name of the library containing the documented material, which is assumed to be a function in a section 2, 3, or 9 manual. The syntax for this is as follows:

.Lb libarm

See Lb.

SYNOPSIS
Documents the utility invocation syntax, function call syntax, or device configuration.

For the first, utilities (sections 1, 6, and 8), this is generally structured as follows:

.Nm foo 
.Op Fl v 
.Op Fl o Ar file 
.Op Ar 
.Nm bar 
.Op Fl v 
.Op Fl o Ar file 
.Op Ar

For the second, function calls (sections 2, 3, 9):

.In header.h 
.Vt extern const char *global; 
.Ft "char *" 
.Fn foo "const char *src" 
.Ft "char *" 
.Fn bar "const char *src"

And for the third, configurations (section 4):

.Cd "it* at isa? port 0x2e" 
.Cd "it* at isa? port 0x4e"

Manuals not in these sections generally don't need a SYNOPSIS.

Some macros are displayed differently in the SYNOPSIS section, particularly Nm, Cd, Fd, Fn, Fo, In, Vt, and Ft. All of these macros are output on their own line. If two such dissimilar macros are pairwise invoked (except for Ft before Fo or Fn), they are separated by a vertical space, unless in the case of Fo, Fn, and Ft, which are always separated by vertical space.

When text and macros following an Nm macro starting an input line span multiple output lines, all output lines but the first will be indented to align with the text immediately following the Nm macro, up to the next Nm, Sh, or Ss macro or the end of an enclosing block, whichever comes first.

DESCRIPTION
This expands upon the brief, one line description in NAME. It usually contains a breakdown of the options (if documenting a command), such as:

The arguments are as follows: 
.Bl -tag -width Ds 
.It Fl v 
Print verbose information. 
.El

Manuals not documenting a command won't include the above fragment.

IMPLEMENTATION NOTES
Implementation-specific notes should be kept here. This is useful when implementing standard functions that may have side effects or notable algorithmic implications.
RETURN VALUES
This section documents the return values of functions in sections 2, 3, and 9.

See Rv.

ENVIRONMENT
Lists the environment variables used by the utility, and explains the syntax and semantics of their values. The environ(7) manual provides examples of typical content and formatting.

See Ev.

FILES
Documents files used. It's helpful to document both the file name and a short description of how the file is used (created, modified, etc.).

See Pa.

EXIT STATUS
This section documents the command exit status for section 1, 6, and 8 utilities. Historically, this information was described in DIAGNOSTICS, a practise that is now discouraged.

See Ex.

EXAMPLES
Example usages. This often contains snippets of well-formed, well-tested invocations. Make sure that examples work properly!
DIAGNOSTICS
Documents error conditions. This is most useful in section 4 manuals. Historically, this section was used in place of EXIT STATUS for manuals in sections 1, 6, and 8; however, this practise is discouraged.

See Bl -diag.

ERRORS
Documents error handling in sections 2, 3, and 9.

See Er.

SEE ALSO
References other manuals with related topics. This section should exist for most manuals. Cross-references should conventionally be ordered first by section, then alphabetically.

See Xr.

STANDARDS
References any standards implemented or used. If not adhering to any standards, the HISTORY section should be used instead.

See St.

HISTORY
A brief history of the subject, including where support first appeared.
AUTHORS
Credits to the person or persons who wrote the code and/or documentation. Authors should generally be noted by both name and email address.

See An.

CAVEATS
Common misuses and misunderstandings should be explained in this section.
BUGS
Known bugs, limitations, and work-arounds should be described in this section.
SECURITY CONSIDERATIONS
Documents any security precautions that operators should consider.

MACRO SYNTAX

Macros are one to three three characters in length and begin with a control character, ‘.', at the beginning of the line. An arbitrary amount of whitespace may sit between the control character and the macro name. Thus, the following are equivalent:

.Pp 
.   Pp

The syntax of a macro depends on its classification. In this section, ‘-arg' refers to macro arguments, which may be followed by zero or more ‘parm' parameters; ‘Yo' opens the scope of a macro; and if specified, ‘Yc' closes it out.

The Callable column indicates that the macro may also be called by passing its name as an argument to another macro. If a macro is not callable but its name appears as an argument to another macro, it is interpreted as opaque text. For example, ‘.Fl Sh' produces ‘-Sh'.

The Parsed column indicates whether the macro may call other macros by receiving their names as arguments. If a macro is not parsed but the name of another macro appears as an argument, it is interpreted as opaque text.

The Scope column, if applicable, describes closure rules.

Block full-explicit

Multi-line scope closed by an explicit closing macro. All macros contains bodies; only Bf contains a head.

.Yo [-arg [parm...]] [head...] 
[body...] 
.Yc

Macro Callable Parsed Scope
Bd No No closed by Ed
Bf No No closed by Ef
Bk No No closed by Ek
Bl No No closed by El
Ed No No opened by Bd
Ef No No opened by Bf
Ek No No opened by Bk
El No No opened by Bl

Block full-implicit

Multi-line scope closed by end-of-file or implicitly by another macro. All macros have bodies; some (It -bullet, -hyphen, -dash, -enum, -item) don't have heads; only one (It in Bl -column) has multiple heads.

.Yo [-arg [parm...]] [head... [Ta head...]] 
[body...]

Macro Callable Parsed Scope
It No Yes closed by It, El
Nd No No closed by Sh
Nm No Yes closed by Nm, Sh, Ss
Sh No No closed by Sh
Ss No No closed by Sh, Ss

Note that the Nm macro is a Block full-implicit macro only when invoked as the first macro in a SYNOPSIS section line, else it is In-line.

Block partial-explicit

Like block full-explicit, but also with single-line scope. Each has at least a body and, in limited circumstances, a head (Fo, Eo) and/or tail (Ec).

.Yo [-arg [parm...]] [head...] 
[body...] 
.Yc [tail...] 
 
.Yo [-arg [parm...]] [head...] [body...] Yc [tail...]

Macro Callable Parsed Scope
Ac Yes Yes opened by Ao
Ao Yes Yes closed by Ac
Bc Yes Yes closed by Bo
Bo Yes Yes opened by Bc
Brc Yes Yes opened by Bro
Bro Yes Yes closed by Brc
Dc Yes Yes opened by Do
Do Yes Yes closed by Dc
Ec Yes Yes opened by Eo
Eo Yes Yes closed by Ec
Fc Yes Yes opened by Fo
Fo No No closed by Fc
Oc Yes Yes closed by Oo
Oo Yes Yes opened by Oc
Pc Yes Yes closed by Po
Po Yes Yes opened by Pc
Qc Yes Yes opened by Oo
Qo Yes Yes closed by Oc
Re No No opened by Rs
Rs No No closed by Re
Sc Yes Yes opened by So
So Yes Yes closed by Sc
Xc Yes Yes opened by Xo
Xo Yes Yes closed by Xc

Block partial-implicit

Like block full-implicit, but with single-line scope closed by Reserved Terms or end of line.

.Yo [-arg [val...]] [body...] [res...]

Macro Callable Parsed
Aq Yes Yes
Bq Yes Yes
Brq Yes Yes
D1 No Yes
Dl No Yes
Dq Yes Yes
Op Yes Yes
Pq Yes Yes
Ql Yes Yes
Qq Yes Yes
Sq Yes Yes
Vt Yes Yes

Note that the Vt macro is a Block partial-implicit only when invoked as the first macro in a SYNOPSIS section line, else it is In-line.

In-line

Closed by Reserved Terms, end of line, fixed argument lengths, and/or subsequent macros. In-line macros have only text children. If a number (or inequality) of arguments is (n), then the macro accepts an arbitrary number of arguments.

.Yo [-arg [val...]] [args...] [res...] 
 
.Yo [-arg [val...]] [args...] Yc... 
 
.Yo [-arg [val...]] arg0 arg1 argN

Macro Callable Parsed Arguments
%A No No >0
%B No No >0
%C No No >0
%D No No >0
%I No No >0
%J No No >0
%N No No >0
%O No No >0
%P No No >0
%Q No No >0
%R No No >0
%T No No >0
%U No No >0
%V No No >0
Ad Yes Yes >0
An Yes Yes >0
Ap Yes Yes 0
Ar Yes Yes n
At Yes Yes 1
Bsx Yes Yes n
Bt No No 0
Bx Yes Yes n
Cd Yes Yes >0
Cm Yes Yes >0
Db No No 1
Dd No No n
Dt No No n
Dv Yes Yes >0
Dx Yes Yes n
Em Yes Yes >0
En No No 0
Er Yes Yes >0
Es No No 0
Ev Yes Yes >0
Ex No No n
Fa Yes Yes >0
Fd No No >0
Fl Yes Yes n
Fn Yes Yes >0
Fr No No n
Ft Yes Yes >0
Fx Yes Yes n
Hf No No n
Ic Yes Yes >0
In No No 1
Lb No No 1
Li Yes Yes >0
Lk Yes Yes >0
Lp No No 0
Ms Yes Yes >0
Mt Yes Yes >0
Nm Yes Yes n
No Yes Yes 0
Ns Yes Yes 0
Nx Yes Yes n
Os No No n
Ot No No n
Ox Yes Yes n
Pa Yes Yes n
Pf Yes Yes 1
Pp No No 0
Rv No No n
Sm No No 1
St No Yes 1
Sx Yes Yes >0
Sy Yes Yes >0
Tn Yes Yes >0
Ud No No 0
Ux Yes Yes n
Va Yes Yes n
Vt Yes Yes >0
Xr Yes Yes >0
br No No 0
sp No No 1

REFERENCE

This section is a canonical reference of all macros, arranged alphabetically. For the scoping of individual macros, see MACRO SYNTAX.

%A

Author name of an Rs block. Multiple authors should each be accorded their own %A line. Author names should be ordered with full or abbreviated forename(s) first, then full surname.

%B

Book title of an Rs block. This macro may also be used in a non-bibliographic context when referring to book titles.

%C

Publication city or location of an Rs block.

%D

Publication date of an Rs block. Recommended formats of arguments are month day, year or just year.

%I

Publisher or issuer name of an Rs block.

%J

Journal name of an Rs block.

%N

Issue number (usually for journals) of an Rs block.

%O

Optional information of an Rs block.

%P

Book or journal page number of an Rs block.

%Q

Institutional author (school, government, etc.) of an Rs block. Multiple institutional authors should each be accorded their own %Q line.

%R

Technical report name of an Rs block.

%T

Article title of an Rs block. This macro may also be used in a non-bibliographical context when referring to article titles.

%U

URI of reference document.

%V

Volume number of an Rs block.

Ac

Close an Ao block. Does not have any tail arguments.

Ad

Memory address. Do not use this for postal addresses.

Examples:

.Ad [0,$]
.Ad 0x00000000

An

Author name. Requires either the name of an author or one of the following arguments:

-split
Start a new output line before each subsequent invocation of An.
-nosplit
The opposite of -split.

The default is -nosplit. The effect of selecting either of the -split modes ends at the beginning of the AUTHORS section. In the AUTHORS section, the default is -nosplit for the first author listing and -split for all other author listings.

Examples:

.An -nosplit
.An Kristaps Dzonsons Aq kristaps@bsd.lv

Ao

Begin a block enclosed by angle brackets. Does not have any head arguments.

Examples:

.Fl -key= Ns Ao Ar val Ac

See also Aq.

Ap

Inserts an apostrophe without any surrounding whitespace. This is generally used as a grammatical device when referring to the verb form of a function.

Examples:

.Fn execve Ap d

Aq

Encloses its arguments in angle brackets.

Examples:

.Fl -key= Ns Aq Ar val

Remarks: this macro is often abused for rendering URIs, which should instead use Lk or Mt, or to note pre-processor “#include” statements, which should use In.

See also Ao.

Ar

Command arguments. If an argument is not provided, the string “file ...” is used as a default.

Examples:

.Fl o Ns Ar file1
.Ar
.Ar arg1, arg2.

At

Formats an AT&T version. Accepts one optional argument:

v[1-7] | 32v
A version of AT&T UNIX.
V[.[1-4]]?
A version of AT&T System V UNIX.

Note that these arguments do not begin with a hyphen.

Examples:

.At
.At V.1

See also Bsx, Bx, Dx, Fx, Nx, Ox, and Ux.

Bc

Close a Bo block. Does not have any tail arguments.

Bd

Begin a display block. Its syntax is as follows:

.Bd -type [-offset width] [-compact]

Display blocks are used to select a different indentation and justification than the one used by the surrounding text. They may contain both macro lines and free-form text lines. By default, a display block is preceded by a vertical space.

The type must be one of the following:

-centered
Centre-justify each line. Using this display type is not recommended; many mdoc implementations render it poorly.
-filled
Left- and right-justify the block.
-literal
Do not justify the block at all. Preserve white space as it appears in the input.
-ragged
Only left-justify the block.
-unfilled
An alias for -literal.

The type must be provided first. Additional arguments may follow:

-offset width
Indent the display by the width, which may be one of the following:
  • One of the pre-defined strings indent, the width of standard indentation; indent-two, twice indent; left, which has no effect; right, which justifies to the right margin; or center, which aligns around an imagined centre axis.
  • A macro invocation, which selects a predefined width associated with that macro. The most popular is the imaginary macro Ds, which resolves to 6n.
  • A width using the syntax described in Scaling Widths.
  • An arbitrary string, which indents by the length of this string.

When the argument is missing, -offset is ignored.

-compact
Do not assert vertical space before the display.

Examples:

.Bd -literal -offset indent -compact 
   Hello       world. 
.Ed

See also D1 and Dl.

Bf

Change the font mode for a scoped block of text. Its syntax is as follows:

.Bf [-emphasis | -literal | -symbolic | Em | Li | Sy]

The -emphasis and Em argument are equivalent, as are -symbolic and Sy, and -literal and Li. Without an argument, this macro does nothing. The font mode continues until broken by a new font mode in a nested scope or Ef is encountered.

See also Li, Ef, Em, and Sy.

Bk

Keep the output generated from each macro input line together on one single output line. Line breaks in free-form text lines are unaffected. The syntax is as follows:

.Bk -words

The -words argument is required; additional arguments are ignored.

The following example will not break within each Op macro line:

.Bk -words 
.Op Fl f Ar flags 
.Op Fl o Ar output 
.Ek

Be careful in using over-long lines within a keep block! Doing so will clobber the right margin.

Bl

Begin a list. Lists consist of items specified using the It macro, containing a head or a body or both. The list syntax is as follows:

.Bl -type [-width val] [-offset val] [-compact] [HEAD ...]

The list type is mandatory and must be specified first. The -width and -offset arguments accept Scaling Widths or use the length of the given string. The -offset is a global indentation for the whole list, affecting both item heads and bodies. For those list types supporting it, the -width argument requests an additional indentation of item bodies, to be added to the -offset. Unless the -compact argument is specified, list entries are separated by vertical space.

A list must specify one of the following list types:

-bullet
No item heads can be specified, but a bullet will be printed at the head of each item. Item bodies start on the same output line as the bullet and are indented according to the -width argument.
-column
A columnated list. The -width argument has no effect; instead, each argument specifies the width of one column, using either the Scaling Widths syntax or the string length of the argument. If the first line of the body of a -column list is not an It macro line, It contexts spanning one input line each are implied until an It macro line is encountered, at which point items start being interpreted as described in the It documentation.
-dash
Like -bullet, except that dashes are used in place of bullets.
-diag
Like -inset, except that item heads are not parsed for macro invocations.
-enum
A numbered list. Formatted like -bullet, except that cardinal numbers are used in place of bullets, starting at 1.
-hang
Like -tag, except that the first lines of item bodies are not indented, but follow the item heads like in -inset lists.
-hyphen
Synonym for -dash.
-inset
Item bodies follow items heads on the same line, using normal inter-word spacing. Bodies are not indented, and the -width argument is ignored.
-item
No item heads can be specified, and none are printed. Bodies are not indented, and the -width argument is ignored.
-ohang
Item bodies start on the line following item heads and are not indented. The -width argument is ignored.
-tag
Item bodies are indented according to the -width argument. When an item head fits inside the indentation, the item body follows this head on the same output line. Otherwise, the body starts on the output line following the head.

See also El and It.

Bo

Begin a block enclosed by square brackets. Does not have any head arguments.

Examples:

.Bo 1 , 
.Dv BUFSIZ Bc

See also Bq.

Bq

Encloses its arguments in square brackets.

Examples:

.Bq 1, Dv BUFSIZ

Remarks: this macro is sometimes abused to emulate optional arguments for commands; the correct macros to use for this purpose are Op, Oo, and Oc.

See also Bo.

Brc

Close a Bro block. Does not have any tail arguments.

Bro

Begin a block enclosed by curly braces. Does not have any head arguments.

Examples:

.Bro 1 , ... , 
.Va n Brc

See also Brq.

Brq

Encloses its arguments in curly braces.

Examples:

.Brq 1, ..., Va n

See also Bro.

Bsx

Format the BSD/OS version provided as an argument, or a default value if no argument is provided.

Examples:

.Bsx 1.0
.Bsx

See also At, Bx, Dx, Fx, Nx, Ox, and Ux.

Bt

Prints “is currently in beta test”.

Bx

Format the BSD version provided as an argument, or a default value if no argument is provided.

Examples:

.Bx 4.4
.Bx

See also At, Bsx, Dx, Fx, Nx, Ox, and Ux.

Cd

Kernel configuration declaration. This denotes strings accepted by config(8).

Examples:

.Cd device le0 at scode?

Remarks: this macro is commonly abused by using quoted literals to retain whitespace and align consecutive Cd declarations. This practise is discouraged.

Cm

Command modifiers. Useful when specifying configuration options or keys.

Examples:

.Cm ControlPath
.Cm ControlMaster

See also Fl.

D1

One-line indented display. This is formatted by the default rules and is useful for simple indented statements. It is followed by a newline.

Examples:

.D1 Fl abcdefgh

See also Bd and Dl.

Db

Switch debugging mode. Its syntax is as follows:

.Db on | off

This macro is ignored by mandoc(1).

Dc

Close a Do block. Does not have any tail arguments.

Dd

Document date. This is the mandatory first macro of any mdoc manual. Its syntax is as follows:

.Dd month day, year

The month is the full English month name, the day is an optionally zero-padded numeral, and the year is the full four-digit year.

Other arguments are not portable; the mandoc(1) utility handles them as follows:

Examples:

.Dd $Mdocdate$
.Dd $Mdocdate: July 21 2007$
.Dd July 21, 2007

See also Dt and Os.

Dl

One-line intended display. This is formatted as literal text and is useful for commands and invocations. It is followed by a newline.

Examples:

.Dl % mandoc mdoc.7 \(ba less

See also Bd and D1.

Do

Begin a block enclosed by double quotes. Does not have any head arguments.

Examples:

.Do 
April is the cruellest month 
.Dc 
\(em T.S. Eliot

See also Dq.

Dq

Encloses its arguments in “typographic” double-quotes.

Examples:

.Dq April is the cruellest month 
\(em T.S. Eliot

See also Qq, Sq, and Do.

Dt

Document title. This is the mandatory second macro of any mdoc file. Its syntax is as follows:

.Dt [title [section [volume | arch]]]

Its arguments are as follows:

title
The document's title (name), defaulting to “UNKNOWN” if unspecified. It should be capitalised.
section
The manual section. This may be one of 1 (utilities), 2 (system calls), 3 (libraries), 3p (Perl libraries), 4 (devices), 5 (file formats), 6 (games), 7 (miscellaneous), 8 (system utilities), 9 (kernel functions), X11 (X Window System), X11R6 (X Window System), unass (unassociated), local (local system), draft (draft manual), or paper (paper). It should correspond to the manual's filename suffix and defaults to “1” if unspecified.
volume
This overrides the volume inferred from section. This field is optional, and if specified, must be one of USD (users' supplementary documents), PS1 (programmers' supplementary documents), AMD (administrators' supplementary documents), SMM (system managers' manuals), URM (users' reference manuals), PRM (programmers' reference manuals), KM (kernel manuals), IND (master index), MMI (master index), LOCAL (local manuals), LOC (local manuals), or CON (contributed manuals).
arch
This specifies a specific relevant architecture. If volume is not provided, it may be used in its place, else it may be used subsequent that. It, too, is optional. It must be one of alpha, amd64, amiga, arc, arm, armish, aviion, hp300, hppa, hppa64, i386, landisk, loongson, luna88k, mac68k, macppc, mips64, mvme68k, mvme88k, mvmeppc, pmax, sgi, socppc, sparc, sparc64, sun3, vax, or zaurus.

Examples:

.Dt FOO 1
.Dt FOO 4 KM
.Dt FOO 9 i386

See also Dd and Os.

Dv

Defined variables such as preprocessor constants.

Examples:

.Dv BUFSIZ
.Dv STDOUT_FILENO

See also Er.

Dx

Format the DragonFly BSD version provided as an argument, or a default value if no argument is provided.

Examples:

.Dx 2.4.1
.Dx

See also At, Bsx, Bx, Fx, Nx, Ox, and Ux.

Ec

Close a scope started by Eo. Its syntax is as follows:

.Ec [TERM]

The TERM argument is used as the enclosure tail, for example, specifying \(rq will emulate Dc.

Ed

End a display context started by Bd.

Ef

End a font mode context started by Bf.

Ek

End a keep context started by Bk.

El

End a list context started by Bl.

See also Bl and It.

Em

Denotes text that should be emphasised. Note that this is a presentation term and should not be used for stylistically decorating technical terms.

Examples:

.Em Warnings!
.Em Remarks:

See also Bf, Sy, and Li.

En

This macro is obsolete and not implemented in mandoc(1).

Eo

An arbitrary enclosure. Its syntax is as follows:

.Eo [TERM]

The TERM argument is used as the enclosure head, for example, specifying \(lq will emulate Do.

Er

Display error constants.

Examples:

.Er EPERM
.Er ENOENT

See also Dv.

Es

This macro is obsolete and not implemented.

Ev

Environmental variables such as those specified in environ(7).

Examples:

.Ev DISPLAY
.Ev PATH

Ex

Insert a standard sentence regarding exit values. Its syntax is as follows:

.Ex -std [utility]

When utility is not specified, the document's name set by Nm is used.

See also Rv.

Fa

Function argument. Its syntax is as follows:

.Fa [argtype] argname

This may be invoked for names with or without the corresponding type. It is also used to specify the field name of a structure. Most often, the Fa macro is used in the SYNOPSIS within Fo section when documenting multi-line function prototypes. If invoked with multiple arguments, the arguments are separated by a comma. Furthermore, if the following macro is another Fa, the last argument will also have a trailing comma.

Examples:

.Fa "const char *p"
.Fa "int a" "int b" "int c"
.Fa foo

See also Fo.

Fc

End a function context started by Fo.

Fd

Historically used to document include files. This usage has been deprecated in favour of In. Do not use this macro.

See also MANUAL STRUCTURE and In.

Fl

Command-line flag. Used when listing arguments to command-line utilities. Prints a fixed-width hyphen ‘-' directly followed by each argument. If no arguments are provided, a hyphen is printed followed by a space. If the argument is a macro, a hyphen is prefixed to the subsequent macro output.

Examples:

.Fl a b c
.Fl Pf a b
.Fl
.Op Fl o Ns Ar file

See also Cm.

Fn

A function name. Its syntax is as follows:

.Fn [functype] funcname [[argtype] argname]

Function arguments are surrounded in parenthesis and are delimited by commas. If no arguments are specified, blank parenthesis are output.

Examples:

.Fn "int funcname" "int arg0" "int arg1"
.Fn funcname "int arg0"
.Fn funcname arg0
.Ft functype 
.Fn funcname

When referring to a function documented in another manual page, use Xr instead. See also MANUAL STRUCTURE and Ft.

Fo

Begin a function block. This is a multi-line version of Fn. Its syntax is as follows:

.Fo funcname

Invocations usually occur in the following context:

.Ft functype
 
.Fo funcname
 
.Fa [argtype] argname
 
...
 
.Fc

A Fo scope is closed by

See also MANUAL STRUCTURE, Fa, Fc, and Ft.

Ft

A function type. Its syntax is as follows:

.Ft functype

Examples:

.Ft int
.Ft functype 
.Fn funcname

See also MANUAL STRUCTURE, Fn, and Fo.

Fx

Format the FreeBSD version provided as an argument, or a default value if no argument is provided.

Examples:

.Fx 7.1
.Fx

See also At, Bsx, Bx, Dx, Nx, Ox, and Ux.

Hf

This macro is obsolete and not implemented.

Ic

Designate an internal or interactive command. This is similar to Cm but used for instructions rather than values.

Examples:

.Ic hash
.Ic alias

Note that using Bd -literal or D1 is preferred for displaying code; the Ic macro is used when referring to specific instructions.

In

An “include” file. In the SYNOPSIS section (only if invoked as the line macro), the first argument is preceded by “#include”, the arguments is enclosed in angle brackets.

Examples:

.In sys/types

See also MANUAL STRUCTURE.

It

A list item. The syntax of this macro depends on the list type.

Lists of type -hang, -ohang, -inset, and -diag have the following syntax:

.It args

Lists of type -bullet, -dash, -enum, -hyphen and -item have the following syntax:

.It

with subsequent lines interpreted within the scope of the It until either a closing El or another It.

The -tag list has the following syntax:

.It [args]

Subsequent lines are interpreted as with -bullet and family. The line arguments correspond to the list's left-hand side; body arguments correspond to the list's contents.

The -column list is the most complicated. Its syntax is as follows:

.It [args]

The args are phrases, a mix of macros and text corresponding to a line column, delimited by tabs or the special ‘Ta' pseudo-macro. Lines subsequent the It are interpreted within the scope of the last phrase. Calling the pseudo-macro ‘Ta' will open a new phrase scope (this must occur on a macro line to be interpreted as a macro). Note that the tab phrase delimiter may only be used within the It line itself. Subsequent this, only the ‘Ta' pseudo-macro may be used to delimit phrases. Furthermore, note that quoted sections propagate over tab-delimited phrases on an It, for example,

.It "col1; <TAB> col2 ;" ;

will preserve the semicolon whitespace except for the last.

See also Bl.

Lb

Specify a library. The syntax is as follows:

.Lb library

The library parameter may be a system library, such as libz or libpam, in which case a small library description is printed next to the linker invocation; or a custom library, in which case the library name is printed in quotes. This is most commonly used in the SYNOPSIS section as described in MANUAL STRUCTURE.

Examples:

.Lb libz
.Lb mdoc

Li

Denotes text that should be in a literal font mode. Note that this is a presentation term and should not be used for stylistically decorating technical terms.

See also Bf, Sy, and Em.

Lk

Format a hyperlink. Its syntax is as follows:

.Lk uri [name]

Examples:

.Lk http://bsd.lv "The BSD.lv Project"
.Lk http://bsd.lv

See also Mt.

Lp

Synonym for Pp.

Ms

Display a mathematical symbol. Its syntax is as follows:

.Ms symbol

Examples:

.Ms sigma
.Ms aleph

Mt

Format a “mailto:” hyperlink. Its syntax is as follows:

.Mt address

Examples:

.Mt discuss@manpages.bsd.lv

Nd

A one line description of the manual's content. This may only be invoked in the SYNOPSIS section subsequent the Nm macro.

Examples:

.Sx Nd mdoc language reference
.Sx Nd format and display UNIX manuals

The Nd macro technically accepts child macros and terminates with a subsequent Sh invocation. Do not assume this behaviour: some whatis(1) database generators are not smart enough to parse more than the line arguments and will display macros verbatim.

See also Nm.

Nm

The name of the manual page, or — in particular in section 1, 6, and 8 pages — of an additional command or feature documented in the manual page. When first invoked, the Nm macro expects a single argument, the name of the manual page. Usually, the first invocation happens in the NAME section of the page. The specified name will be remembered and used whenever the macro is called again without arguments later in the page. The Nm macro uses Block full-implicit semantics when invoked as the first macro on an input line in the SYNOPSIS section; otherwise, it uses ordinary In-line semantics.

Examples:

.Sh SYNOPSIS 
.Nm cat 
.Op Fl benstuv 
.Op Ar

In the SYNOPSIS of section 2, 3 and 9 manual pages, use the Fn macro rather than Nm to mark up the name of the manual page.

No

A “noop” macro used to terminate prior macro contexts.

Examples:

.Sx Fl ab No cd Fl ef

Ns

Suppress a space. Following invocation, text is interpreted as free-form text until a macro is encountered.

This has no effect when invoked at the start of a macro line.

Examples:

.Fl o Ns Ar output

See also No and Sm.

Nx

Format the NetBSD version provided as an argument, or a default value if no argument is provided.

Examples:

.Nx 5.01
.Nx

See also At, Bsx, Bx, Dx, Fx, Ox, and Ux.

Oc

Close multi-line Oo context.

Oo

Multi-line version of Op.

Examples:

.Oo 
.Op Fl flag Ns Ar value 
.Oc

Op

Command-line option. Used when listing options to command-line utilities. Prints the argument(s) in brackets.

Examples:

.Op Fl a Ar b
.Op Ar a | b

See also Oo.

Os

Document operating system version. This is the mandatory third macro of any mdoc file. Its syntax is as follows:

.Os [system [version]]

The optional system parameter specifies the relevant operating system or environment. Left unspecified, it defaults to the local operating system version. This is the suggested form.

Examples:

.Os
.Os KTH/CSC/TCS
.Os BSD 4.3

See also Dd and Dt.

Ot

Unknown usage.

Remarks: this macro has been deprecated.

Ox

Format the OpenBSD version provided as an argument, or a default value if no argument is provided.

Examples:

.Ox 4.5
.Ox

See also At, Bsx, Bx, Dx, Fx, Nx, and Ux.

Pa

A file-system path. If an argument is not provided, the string “~” is used as a default.

Examples:

.Pa /usr/bin/mandoc
.Pa /usr/share/man/man7/mdoc.7

See also Lk.

Pc

Close parenthesised context opened by Po.

Pf

Removes the space (“prefix”) between its arguments. Its syntax is as follows:

.Pf prefix suffix

The suffix argument may be a macro.

Examples:

.Pf \. Sx Pf Cm prefix suffix

Po

Multi-line version of Pq.

Pp

Break a paragraph. This will assert vertical space between prior and subsequent macros and/or text.

Pq

Parenthesised enclosure.

See also Po.

Qc

Close quoted context opened by Qo.

Ql

Format a single-quoted literal. See also Qq and Sq.

Qo

Multi-line version of Qq.

Qq

Encloses its arguments in “typewriter” double-quotes. Consider using Dq.

See also Dq, Sq, and Qo.

Re

Close an Rs block. Does not have any tail arguments.

Rs

Begin a bibliographic (“reference”) block. Does not have any head arguments. The block macro may only contain %A, %B, %C, %D, %I, %J, %N, %O, %P, %Q, %R, %T, %U, and %V child macros (at least one must be specified).

Examples:

.Rs 
.%A J. E. Hopcroft 
.%A J. D. Ullman 
.%B Introduction to Automata Theory, Languages, and Computation 
.%I Addison-Wesley 
.%C Reading, Massachusettes 
.%D 1979 
.Re

If an Rs block is used within a SEE ALSO section, a vertical space is asserted before the rendered output, else the block continues on the current line.

Rv

Inserts text regarding a function call's return value. This macro must consist of the -std argument followed by an optional function. If function is not provided, the document's name as stipulated by the first Nm is provided.

See also Ex.

Sc

Close single-quoted context opened by So.

Sh

Begin a new section. For a list of conventional manual sections, see MANUAL STRUCTURE. These sections should be used unless it's absolutely necessary that custom sections be used.

Section names should be unique so that they may be keyed by Sx.

See also Pp, Ss, and Sx.

Sm

Switches the spacing mode for output generated from macros. Its syntax is as follows:

.Sm on | off

By default, spacing is on. When switched off, no white space is inserted between macro arguments and between the output generated from adjacent macros, but free-form text lines still get normal spacing between words and sentences.

So

Multi-line version of Sq.

Sq

Encloses its arguments in “typewriter” single-quotes.

See also Dq, Qq, and So.

Ss

Begin a new sub-section. Unlike with Sh, there's no convention for sub-sections. Conventional sections, as described in MANUAL STRUCTURE, rarely have sub-sections.

Sub-section names should be unique so that they may be keyed by Sx.

See also Pp, Sh, and Sx.

St

Replace an abbreviation for a standard with the full form. The following standards are recognised:

-p1003.1-88
IEEE Std 1003.1-1988 (“POSIX.1”)
-p1003.1-90
IEEE Std 1003.1-1990 (“POSIX.1”)
-p1003.1-96
ISO/IEC 9945-1:1996 (“POSIX.1”)
-p1003.1-2001
IEEE Std 1003.1-2001 (“POSIX.1”)
-p1003.1-2004
IEEE Std 1003.1-2004 (“POSIX.1”)
-p1003.1-2008
IEEE Std 1003.1-2008 (“POSIX.1”)
-p1003.1
IEEE Std 1003.1 (“POSIX.1”)
-p1003.1b
IEEE Std 1003.1b (“POSIX.1”)
-p1003.1b-93
IEEE Std 1003.1b-1993 (“POSIX.1”)
-p1003.1c-95
IEEE Std 1003.1c-1995 (“POSIX.1”)
-p1003.1g-2000
IEEE Std 1003.1g-2000 (“POSIX.1”)
-p1003.1i-95
IEEE Std 1003.1i-1995 (“POSIX.1”)
-p1003.2-92
IEEE Std 1003.2-1992 (“POSIX.2”)
-p1003.2a-92
IEEE Std 1003.2a-1992 (“POSIX.2”)
-p1387.2-95
IEEE Std 1387.2-1995 (“POSIX.7.2”)
-p1003.2
IEEE Std 1003.2 (“POSIX.2”)
-p1387.2
IEEE Std 1387.2 (“POSIX.7.2”)
-isoC
ISO/IEC 9899:1990 (“ISO C90”)
-isoC-90
ISO/IEC 9899:1990 (“ISO C90”)
-isoC-amd1
ISO/IEC 9899/AMD1:1995 (“ISO C90”)
-isoC-tcor1
ISO/IEC 9899/TCOR1:1994 (“ISO C90”)
-isoC-tcor2
ISO/IEC 9899/TCOR2:1995 (“ISO C90”)
-isoC-99
ISO/IEC 9899:1999 (“ISO C99”)
-iso9945-1-90
ISO/IEC 9945-1:1990 (“POSIX.1”)
-iso9945-1-96
ISO/IEC 9945-1:1996 (“POSIX.1”)
-iso9945-2-93
ISO/IEC 9945-2:1993 (“POSIX.2”)
-ansiC
ANSI X3.159-1989 (“ANSI C”)
-ansiC-89
ANSI X3.159-1989 (“ANSI C”)
-ansiC-99
ANSI/ISO/IEC 9899-1999 (“ANSI C99”)
-ieee754
IEEE Std 754-1985
-iso8802-3
ISO 8802-3: 1989
-ieee1275-94
IEEE Std 1275-1994 (“Open Firmware”)
-xpg3
X/Open Portability Guide Issue 3 (“XPG3”)
-xpg4
X/Open Portability Guide Issue 4 (“XPG4”)
-xpg4.2
X/Open Portability Guide Issue 4.2 (“XPG4.2”) X/Open Portability Guide Issue 4.3 (“XPG4.3”)
-xbd5
X/Open System Interface Definitions Issue 5 (“XBD5”)
-xcu5
X/Open Commands and Utilities Issue 5 (“XCU5”)
-xsh5
X/Open System Interfaces and Headers Issue 5 (“XSH5”)
-xns5
X/Open Networking Services Issue 5 (“XNS5”)
-xns5.2
X/Open Networking Services Issue 5.2 (“XNS5.2”)
-xns5.2d2.0
X/Open Networking Services Issue 5.2 Draft 2.0 (“XNS5.2D2.0”)
-xcurses4.2
X/Open Curses Issue 4 Version 2 (“XCURSES4.2”)
-susv2
Version 2 of the Single UNIX Specification
-susv3
Version 3 of the Single UNIX Specification
-svid4
System V Interface Definition, Fourth Edition (“SVID4”)

Sx

Reference a section or sub-section. The referenced section or sub-section name must be identical to the enclosed argument, including whitespace.

Examples:

.Sx MANUAL STRUCTURE

See also Sh and Ss.

Sy

Format enclosed arguments in symbolic (“boldface”). Note that this is a presentation term and should not be used for stylistically decorating technical terms.

See also Bf, Li, and Em.

Tn

Format a tradename.

Examples:

.Tn IBM

Ud

Prints out “currently under development”.

Ux

Format the UNIX name. Accepts no argument.

Examples:

.Ux

See also At, Bsx, Bx, Dx, Fx, Nx, and Ox.

Va

A variable name.

Examples:

.Va foo
.Va const char *bar;

Vt

A variable type. This is also used for indicating global variables in the SYNOPSIS section, in which case a variable name is also specified. Note that it accepts Block partial-implicit syntax when invoked as the first macro in the SYNOPSIS section, else it accepts ordinary In-line syntax.

Note that this should not be confused with Ft, which is used for function return types.

Examples:

.Vt unsigned char
.Vt extern const char * const sys_signame[] ;

See also MANUAL STRUCTURE and Va.

Xc

Close a scope opened by Xo.

Xo

Extend the header of an It macro or the body of a partial-implicit block macro beyond the end of the input line. This macro originally existed to work around the 9-argument limit of historic roff(7).

Xr

Link to another manual (“cross-reference”). Its syntax is as follows:

.Xr name section

The name and section are the name and section of the linked manual. If section is followed by non-punctuation, an Ns is inserted into the token stream. This behaviour is for compatibility with GNU troff.

Examples:

.Xr mandoc 1
.Xr mandoc 1 ;
.Xr mandoc 1 Ns s behaviour

br

Emits a line-break. This macro should not be used; it is implemented for compatibility with historical manuals.

Consider using Pp in the event of natural paragraph breaks.

sp

Emits vertical space. This macro should not be used; it is implemented for compatibility with historical manuals. Its syntax is as follows:

.sp [height]

The height argument must be formatted as described in Scaling Widths. If unspecified, sp asserts a single vertical space.

COMPATIBILITY

This section documents compatibility between mandoc and other other troff implementations, at this time limited to GNU troff (“groff”). The term “historic groff” refers to groff versions before 1.17, which featured a significant update of the doc.tmac file.

Heirloom troff, the other significant troff implementation accepting -mdoc, is similar to historic groff.

The following problematic behaviour is found in groff:

The following features are unimplemented in mandoc:

SEE ALSO

man(1), mandoc(1), eqn(7), man(7), mandoc_char(7) roff(7), tbl(7)

HISTORY

The mdoc language first appeared as a troff macro package in 4.4BSD. It was later significantly updated by Werner Lemberg and Ruslan Ermilov in groff-1.17. The standalone implementation that is part of the mandoc(1) utility written by Kristaps Dzonsons appeared in OpenBSD 4.6.

AUTHORS

The mdoc reference was written by Kristaps Dzonsons <kristaps@bsd.lv>.
April 1, 2011 NetBSD 5.99