Sortix volatile manual

This manual documents Sortix volatile, a development build that has not been officially released. You can instead view this document in the latest official manual.

NAME

mdoc — semantic markup language for formatting manual pages

DESCRIPTION

The mdoc language supports authoring of manual pages for the man(1) utility by allowing semantic annotations of words, phrases, page sections and complete manual pages. Such annotations are used by formatting tools to achieve a uniform presentation across all manuals written in mdoc, and to support hyperlinking if supported by the output medium.

This reference document describes the structure of manual pages and the syntax and usage of the mdoc language. The reference implementation of a parsing and formatting tool is mandoc(1); the COMPATIBILITY section describes compatibility with other implementations.

In an mdoc document, lines beginning with the control character ‘.’ are called “macro lines”. The first word is the macro name. It consists of two or three letters. Most macro names begin with a capital letter. For a list of available macros, see MACRO OVERVIEW. The words following the macro name are arguments to the macro, optionally including the names of other, callable macros; see MACRO SYNTAX for details.

Lines not beginning with the control character are called “text lines”. They provide free-form text to be printed; the formatting of the text depends on the respective processing context:

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

Many aspects of the basic syntax of the mdoc language are based on the roff(7) language; see the LANGUAGE SYNTAX and MACRO SYNTAX sections in the roff(7) manual for details, in particular regarding comments, escape sequences, whitespace, and quoting. However, using roff(7) requests in mdoc documents is discouraged; mandoc(1) supports some of them merely for backward compatibility.

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 for a utility “progname”:

.Dd $Mdocdate$ 
.Dt PROGNAME section 
.Os 
.Sh NAME 
.Nm progname 
.Nd one line about what it does 
.\" .Sh LIBRARY 
.\" For sections 2, 3, and 9 only. 
.\" Not used in OpenBSD. 
.Sh SYNOPSIS 
.Nm progname 
.Op Fl options 
.Ar 
.Sh DESCRIPTION 
The 
.Nm 
utility processes files ... 
.\" .Sh CONTEXT 
.\" For section 9 functions only. 
.\" .Sh IMPLEMENTATION NOTES 
.\" Not used in OpenBSD. 
.\" .Sh RETURN VALUES 
.\" For sections 2, 3, and 9 function return values only. 
.\" .Sh ENVIRONMENT 
.\" For sections 1, 6, 7, and 8 only. 
.\" .Sh FILES 
.\" .Sh EXIT STATUS 
.\" For sections 1, 6, and 8 only. 
.\" .Sh EXAMPLES 
.\" .Sh DIAGNOSTICS 
.\" For sections 1, 4, 6, 7, 8, and 9 printf/stderr messages only. 
.\" .Sh ERRORS 
.\" For sections 2, 3, 4, and 9 errno settings 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

Multiple ‘Nm’ names should be separated by commas.

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

Commands should be ordered alphabetically.

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"

Ordering of In, Vt, Fn, and Fo macros should follow C header-file conventions.

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 begins with an expansion of the brief, one line description in NAME:

The 
.Nm 
utility does this, that, and the other.

It usually follows with 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.

Since the DESCRIPTION section usually contains most of the text of a manual, longer manuals often use the Ss macro to form subsections. In very long manuals, the DESCRIPTION may be split into multiple sections, each started by an Sh macro followed by a non-standard section name, and each having several subsections, like in the present mdoc manual.

CONTEXT

This section lists the contexts in which functions can be called in section 9. The contexts are autoconf, process, or interrupt.

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 messages. In section 4 and 9 manuals, these are usually messages printed by the kernel to the console and to the kernel log. In section 1, 6, 7, and 8, these are usually messages printed by userland programs to the standard error output.

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 errno(2) settings in sections 2, 3, 4, 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 (ignoring case).

References to other documentation concerning the topic of the manual page, for example authoritative books or journal articles, may also be provided in this section.

See Rs and 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 it was first implemented, and when it was ported to or reimplemented for the operating system at hand.

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 OVERVIEW

This overview is sorted such that macros of similar purpose are listed together, to help find the best macro for any given purpose. Deprecated macros are not included in the overview, but can be found below in the alphabetical MACRO REFERENCE.

Document preamble and NAME section macros

Dd	document date: $Mdocdate$ \| month day, year
Dt	document title: TITLE section [arch]
Os	operating system version: [system [version]]
Nm	document name (one argument)
Nd	document description (one line)

Sections and cross references

Sh	section header (one line)
Ss	subsection header (one line)
Sx	internal cross reference to a section or subsection
Xr	cross reference to another manual page: name section
Pp, Lp	start a text paragraph (no arguments)

Displays and lists

Bd, Ed	display block: -type [-offset width] [-compact]
D1	indented display (one line)
Dl	indented literal display (one line)
Ql	in-line literal display: ‘`text`’
Bl, El	list block: -type [-width val] [-offset val] [-compact]
It	list item (syntax depends on -type)
Ta	table cell separator in Bl -column `lists`
Rs, %*, Re	bibliographic block (references)

Spacing control

Pf	prefix, no following horizontal space (one argument)
Ns	roman font, no preceding horizontal space (no arguments)
Ap	apostrophe without surrounding whitespace (no arguments)
Sm	switch horizontal spacing mode: [on \| off]
Bk, Ek	keep block: -words
br	force output line break in text mode (no arguments)
sp	force vertical space: [height]

Semantic markup for command line utilities:

Nm	start a SYNOPSIS block with the name of a utility
Fl	command line options (flags) (>=0 arguments)
Cm	command modifier (>0 arguments)
Ar	command arguments (>=0 arguments)
Op, Oo, Oc	optional syntax elements (enclosure)
Ic	internal or interactive command (>0 arguments)
Ev	environmental variable (>0 arguments)
Pa	file system path (>=0 arguments)

Semantic markup for function libraries:

Lb	function library (one argument)
In	include file (one argument)
Fd	other preprocessor directive (>0 arguments)
Ft	function type (>0 arguments)
Fo, Fc	function block: funcname
Fn	function name: [functype] funcname [[argtype] argname]
Fa	function argument (>0 arguments)
Vt	variable type (>0 arguments)
Va	variable name (>0 arguments)
Dv	defined variable or preprocessor constant (>0 arguments)
Er	error constant (>0 arguments)
Ev	environmental variable (>0 arguments)

Various semantic markup:

An	author name (>0 arguments)
Lk	hyperlink: uri [name]
Mt	“mailto” hyperlink: address
Cd	kernel configuration declaration (>0 arguments)
Ad	memory address (>0 arguments)
Ms	mathematical symbol (>0 arguments)

Physical markup

Em	italic font or underline (emphasis) (>0 arguments)
Sy	boldface font (symbolic) (>0 arguments)
Li	typewriter font (literal) (>0 arguments)
No	return to roman font (normal) (no arguments)
Bf, Ef	font block: [-type \| Em \| Li \| Sy]

Physical enclosures

Dq, Do, Dc	enclose in typographic double quotes: “text”
Qq, Qo, Qc	enclose in typewriter double quotes: “text”
Sq, So, Sc	enclose in single quotes: ‘text’
Pq, Po, Pc	enclose in parentheses: (text)
Bq, Bo, Bc	enclose in square brackets: [text]
Brq, Bro, Brc	enclose in curly braces: {text}
Aq, Ao, Ac	enclose in angle brackets: ⟨text⟩
Eo, Ec	generic enclosure

Text production

Ex -std	standard command exit values: [utility ...]
Rv -std	standard function return values: [function ...]
St	reference to a standards document (one argument)
At	AT&T UNIX
Bx	BSD
Bsx	BSD/OS
Nx	NetBSD
Fx	FreeBSD
Ox	OpenBSD
Dx	DragonFly

MACRO 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.

Memory address. Do not use this for postal addresses.

Examples:

.Ad [0,$]

.Ad 0x00000000

An

Author name. Can be used both for the authors of the program, function, or driver documented in the manual, or for the authors of the manual itself. Requires either the name of an author or one of the following arguments:

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 Mt 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

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.

Ar

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

Examples:

.Fl o Ar file

.Ar

.Ar arg1 , arg2 .

The arguments to the Ar macro are names and placeholders for command arguments; for fixed strings to be passed verbatim as arguments, use Fl or Cm.

At

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

Note that these arguments do not begin with a hyphen.

Examples:

.At

.At III

.At V.1

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 text lines. By default, a display block is preceded by a vertical space.

The type must be one of the following:

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

Examples:

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

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.

Bk

For each macro, keep its output together on the same output line, until the end of the macro or the end of the input line is reached, whichever comes first. Line breaks in 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 macro names as described for Bd -offset, scaling widths as described in roff(7), 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:

Lists may be nested within lists and displays. Nesting of -column and -enum lists may not be portable.

Bo

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

Examples:

.Bo 1 , 
.Dv BUFSIZ Bc

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.

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

Brq

Encloses its arguments in curly braces.

Examples:

.Brq 1, ..., Va n

Bsx

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

Examples:

.Bsx 1.0

.Bsx

Bt

Supported only for compatibility, do not use this in new manuals. 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 4.3 Tahoe

.Bx 4.4

.Bx

Cd

Kernel configuration declaration. This denotes strings accepted by config(8). It is most often used in section 4 manual pages.

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. Typically used for fixed strings passed as arguments, unless Fl is more appropriate. Also useful when specifying configuration options or keys.

Examples:

.Nm mt Fl f Ar device Cm rewind

.Nm ps Fl o Cm pid , Ns Cm command

.Nm dd Cm if= Ns Ar file1 Cm of= Ns Ar file2

.Cm IdentityFile Pa ~/.ssh/id_rsa

.Cm LogLevel Dv DEBUG

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

Db

This macro is obsolete. No replacement is needed. It is ignored by mandoc(1) and groff including its arguments. It was formerly used to toggle a debugging mode.

Dc

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

Dd

Document date for display in the page footer. 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:

To have the date automatically filled in by the OpenBSD version of cvs(1), the special string “$Mdocdate$” can be given as an argument.
The traditional, purely numeric man(7) format year–month–day is accepted, too.
If a date string cannot be parsed, it is used verbatim.
If no date string is given, the current date is used.

Examples:

.Dd $Mdocdate$

.Dd $Mdocdate: July 21 2007$

.Dd July 21, 2007

Dl

One-line indented 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

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

Dq

Encloses its arguments in “typographic” double-quotes.

Examples:

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

Dt

Document title for display in the page header. This is the mandatory second macro of any mdoc file. Its syntax is as follows:

.Dt TITLE section [arch]

Its arguments are as follows:

Examples:

.Dt FOO 1

.Dt FOO 9 i386

Dv

Defined variables such as preprocessor constants, constant symbols, enumeration values, and so on.

Examples:

.Dv NULL

.Dv BUFSIZ

.Dv STDOUT_FILENO

See also Er and Ev for special-purpose constants, Va for variable symbols, and Fd for listing preprocessor variable definitions in the SYNOPSIS.

Dx

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

Examples:

.Dx 2.4.1

.Dx

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.

Em

Request an italic font. If the output device does not provide that, underline.

This is most often used for stress emphasis (not to be confused with importance, see Sy). In the rare cases where none of the semantic markup macros fit, it can also be used for technical terms and placeholders, except that for syntax elements, Sy and Ar are preferred, respectively.

Examples:

Selected lines are those 
.Em not 
matching any of the specified patterns. 
Some of the functions use a 
.Em hold space 
to save the pattern space for subsequent retrieval.

En

This macro is obsolete. Use Eo or any of the other enclosure macros.

It encloses its argument in the delimiters specified by the last Es macro.

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

Error constants for definitions of the errno libc global variable. This is most often used in section 2 and 3 manual pages.

Examples:

.Er EPERM

.Er ENOENT

Es

This macro is obsolete. Use Eo or any of the other enclosure macros.

It takes two arguments, defining the delimiters to be used by subsequent En macros.

Ev

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

Examples:

.Ev DISPLAY

.Ev PATH

Ex

Insert a standard sentence regarding command exit values of 0 on success and >0 on failure. This is most often used in section 1, 6, and 8 manual pages. Its syntax is as follows:

.Ex -std [utility ...]

If utility is not specified, the document's name set by Nm is used. Multiple utility arguments are treated as separate utilities.

Fa

Function argument or parameter. Its syntax is as follows:

.Fa “[argtype] [argname]” ...

Each argument may be a name and a type (recommended for the SYNOPSIS section), a name alone (for function invocations), or a type alone (for function prototypes). If both a type and a name are given or if the type consists of multiple words, all words belonging to the same function argument have to be given in a single argument to the Fa macro.

This macro is also used to specify the field name of a structure.

Most often, the Fa macro is used in the SYNOPSIS within Fo blocks 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 "char *" size_t

Fc

End a function context started by Fo.

Fd

Preprocessor directive, in particular for listing it in the SYNOPSIS. Historically, it was also used to document include files. The latter usage has been deprecated in favour of In.

Its syntax is as follows:

.Fd #directive [argument ...]

Examples:

.Fd #define sa_handler __sigaction_u.__sa_handler

.Fd #define SIO_MAXNFDS

.Fd #ifdef FS_DEBUG

.Ft void

.Fn dbg_open "const char *"

.Fd #endif

See also MANUAL STRUCTURE, In, and Dv.

Fl

Command-line flag or option. 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 R Op Fl H | L | P

.Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux

.Fl type Cm d Fl name Pa CVS

.Fl Ar signal_number

.Fl o Fl

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. In the SYNOPSIS section, this macro starts a new output line, and a blank line is automatically inserted between function definitions.

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, Fo, 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 Fc.

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

Fr

This macro is obsolete. No replacement markup is needed.

It was used to show numerical function return values in an italic font.

Ft

A function type. Its syntax is as follows:

.Ft functype

In the SYNOPSIS section, a new output line is started after this macro.

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

Hf

This macro is not implemented in mandoc(1).

It was used to include the contents of a (header) file literally. The syntax was:

.Hf filename

Ic

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

Examples:

.Ic :wq

.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

The name of an include file. This macro is most often used in section 2, 3, and 9 manual pages.

When invoked as the first macro on an input line in the SYNOPSIS section, the argument is displayed in angle brackets and preceded by “#include”, and a blank line is inserted in front if there is a preceding function declaration. In other sections, it only encloses its argument in angle brackets and causes no line break.

Examples:

.In sys/types.h

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 cell [<TAB> cell ...]

.It cell [Ta cell ...]

The arguments consist of one or more lines of text and macros representing a complete table line. Cells within the line are delimited by tabs or by the special Ta block macro. The tab cell delimiter may only be used within the It line itself; on following lines, only the Ta macro can be used to delimit cells, and Ta is only recognised as a macro when called by other macros, not as the first macro on a line.

Note that quoted strings may span tab-delimited cells on an It line. For example,

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

will preserve the semicolon whitespace except for the last.

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 libmandoc

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.

On terminal output devices, this is often indistinguishable from normal text.

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

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

.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv

Nd

A one line description of the manual's content. This is the mandatory last macro of the NAME section and not appropriate for other sections.

Examples:

.Nd mdoc language reference

.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.

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

Normal text. Closes the scope of any preceding in-line macro. When used after physical formatting macros like Em or Sy, switches back to the standard font face and weight. Can also be used to embed plain text strings in macro lines using semantic annotation macros.

Examples:

.Em italic , Sy bold , No and roman

.Sm off 
.Cm :C No / Ar pattern No / Ar replacement No / 
.Sm on

Ns

Suppress a space between the output of the preceding macro and the following text or macro. Following invocation, input is interpreted as normal text just like after an No macro.

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

Examples:

.Ar name Ns = Ns Ar value

.Cm :M Ns Ar pattern

.Fl o Ns Ar output

Nx

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

Examples:

.Nx 5.01

.Nx

Oc

Close multi-line Oo context.

Oo

Multi-line version of Op.

Examples:

.Oo 
.Op Fl flag Ns Ar value 
.Oc

Op

Optional part of a command line. Prints the argument(s) in brackets. This is most often used in the SYNOPSIS section of section 1 and 8 manual pages.

Examples:

.Op Fl a Ar b

.Op Ar a | b

Os

Operating system version for display in the page footer. 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. It is suggested to leave it unspecified, in which case mandoc(1) uses its -Ios argument, or, if that isn't specified either, sysname and release as returned by uname(3).

Examples:

.Os

.Os KTH/CSC/TCS

.Os BSD 4.3

Ot

This macro is obsolete. Use Ft instead; with mandoc(1), both have the same effect.

Historical mdoc packages described it as “old function type (FORTRAN)”.

Ox

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

Examples:

.Ox 4.5

.Ox

Pa

An absolute or relative file system path, or a file or directory name. If an argument is not provided, the character ‘~’ is used as a default.

Examples:

.Pa /usr/bin/mandoc

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

Pc

Close parenthesised context opened by Po.

Pf

Removes the space between its argument (“prefix”) and the following macro. Its syntax is as follows:

.Pf prefix macro arguments ...

This is equivalent to:

.No prefix Ns macro arguments ...

Examples:

.Pf $ Ar variable_name

.Pf 0x Ar hex_digits

Po

Multi-line version of Pq.

Pp

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

Paragraph breaks are not needed before or after Sh or Ss macros or before displays (Bd) or lists (Bl) unless the -compact flag is given.

Pq

Parenthesised enclosure.

Qc

Close quoted context opened by Qo.

Ql

In-line literal display. This can for example be used for complete command invocations and for multi-word code fragments when more specific markup is not appropriate and an indented display is not desired. While mandoc(1) always encloses the arguments in single quotes, other formatters usually omit the quotes on non-terminal output devices when the arguments have three or more characters.

Qo

Multi-line version of Qq.

Qq

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

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

Insert a standard sentence regarding a function call's return value of 0 on success and -1 on error, with the errno libc global variable set on error. Its syntax is as follows:

.Rv -std [function ...]

If function is not specified, the document's name set by Nm is used. Multiple function arguments are treated as separate functions.

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. Although this macro is parsed, it should not consist of child node or it may not be linked with 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 text lines still get normal spacing between words and sentences.

When called without an argument, the Sm macro toggles the spacing mode. Using this is not recommended because it makes the code harder to read.

So

Multi-line version of Sq.

Sq

Encloses its arguments in ‘typewriter’ single-quotes.

Ss

Begin a new subsection. Unlike with Sh, there is no convention for the naming of subsections. Except DESCRIPTION, the conventional sections described in MANUAL STRUCTURE rarely have subsections.

Sub-section names should be unique so that they may be keyed by Sx. Although this macro is parsed, it should not consist of child node or it may not be linked with Sx.

St

Replace an abbreviation for a standard with the full form. The following standards are recognised. Where multiple lines are given without a blank line in between, they all refer to the same standard, and using the first form is recommended.

Sx

Reference a section or subsection in the same manual page. The referenced section or subsection name must be identical to the enclosed argument, including whitespace.

Examples:

.Sx MANUAL STRUCTURE

Sy

Request a boldface font.

This is most often used to indicate importance or seriousness (not to be confused with stress emphasis, see Em). When none of the semantic macros fit, it is also adequate for syntax elements that have to be given or that appear verbatim.

Examples:

.Sy Warning : 
If 
.Sy s 
appears in the owner permissions, set-user-ID mode is set. 
This utility replaces the former 
.Sy dumpdir 
program.

Ta

Table cell separator in Bl -column lists; can only be used below It.

Tn

Supported only for compatibility, do not use this in new manuals. Even though the macro name (“tradename”) suggests a semantic function, historic usage is inconsistent, mostly using it as a presentation-level macro to request a small caps font.

Ud

Supported only for compatibility, do not use this in new manuals. Prints out “currently under development.”

Ux

Supported only for compatibility, do not use this in new manuals. Prints out “UNIX”.

Va

A variable name.

Examples:

.Va foo

.Va const char *bar;

For function arguments and parameters, use Fa instead. For declarations of global variables in the SYNOPSIS section, use Vt.

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 on an input line in the SYNOPSIS section, else it accepts ordinary In-line syntax. In the former case, this macro starts a new output line, and a blank line is inserted in front if there is a preceding function definition or include directive.

Examples:

.Vt unsigned char

.Vt extern const char * const sys_signame[] ;

For parameters in function prototypes, use Fa instead, for function return types Ft, and for variable names outside the SYNOPSIS section Va, even when including a type with the name. See also MANUAL STRUCTURE.

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]

Cross reference the name and section number of another man page; omitting the section number is rarely useful.

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 is a scaling width as described in roff(7). If unspecified, sp asserts a single vertical space.

MACRO SYNTAX

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. For example, ‘.Op Fl O Ar file’ produces ‘[-O file]’. To prevent a macro call and render the macro name literally, escape it by prepending a zero-width space, ‘\&’. For example, ‘Op \&Fl O’ produces ‘[Fl O]’. 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 and (optionally) Bl contain 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	Yes	closed by Sh
Ss	No	Yes	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 the end of the 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
En	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.

Special block macro

The Ta macro can only be used below It in Bl -column lists. It delimits blocks representing table cells; these blocks have bodies, but no heads.

Macro	Callable	Parsed	Scope
Ta	Yes	Yes	closed by Ta, It

In-line

Closed by the end of the 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
Er	Yes	Yes	>0
Es	Yes	Yes	2
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	Yes	Yes	>0
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	Yes	Yes	>0
Ox	Yes	Yes	n
Pa	Yes	Yes	n
Pf	Yes	Yes	1
Pp	No	No	0
Rv	No	No	n
Sm	No	No	<2
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

Delimiters

When a macro argument consists of one single input character considered as a delimiter, the argument gets special handling. This does not apply when delimiters appear in arguments containing more than one character. Consequently, to prevent special handling and just handle it like any other argument, a delimiter can be escaped by prepending a zero-width space (‘\&’). In text lines, delimiters never need escaping, but may be used as normal punctuation.

For many macros, when the leading arguments are opening delimiters, these delimiters are put before the macro scope, and when the trailing arguments are closing delimiters, these delimiters are put after the macro scope. For example,

.Aq ( [ word ] ) .

renders as:

([⟨word⟩]).

Opening delimiters are:

Closing delimiters are:

Note that even a period preceded by a backslash (‘\.’) gets this special handling; use ‘\&.’ to prevent that.

Many in-line macros interrupt their scope when they encounter delimiters, and resume their scope when more arguments follow that are not delimiters. For example,

.Fl a ( b | c \*(Ba d ) e

renders as:

-a (-b | -c | -d) -e

This applies to both opening and closing delimiters, and also to the middle delimiter:

As a special case, the predefined string \*(Ba is handled and rendered in the same way as a plain ‘|’ character. Using this predefined string is not recommended in new manuals.

Font handling

In mdoc documents, usage of semantic markup is recommended in order to have proper fonts automatically selected; only when no fitting semantic markup is available, consider falling back to Physical markup macros. Whenever any mdoc macro switches the roff(7) font mode, it will automatically restore the previous font when exiting its scope. Manually switching the font using the roff(7) ‘\f’ font escape sequences is never required.

COMPATIBILITY

This section provides an incomplete list of compatibility issues between mandoc and GNU troff (“groff”).

The following problematic behaviour is found in groff:

Dd with non-standard arguments behaves very strangely. When there are three arguments, they are printed verbatim. Any other number of arguments is replaced by the current date, but without any arguments the string “Epoch” is printed.
Lk only accepts a single link-name argument; the remainder is misformatted.
Pa does not format its arguments when used in the FILES section under certain list types.
Ta can only be called by other macros, but not at the beginning of a line.
%C is not implemented (up to and including groff-1.22.2).
‘\f’ (font face) and ‘\F’ (font family face) Text Decoration escapes behave irregularly when specified within line-macro scopes.
Negative scaling units return to prior lines. Instead, mandoc truncates them to zero.

The following features are unimplemented in mandoc:

Bd -file file is unsupported for security reasons.
Bd -filled does not adjust the right margin, but is an alias for Bd -ragged.
Bd -literal does not use a literal font, but is an alias for Bd -unfilled.
Bd -offset center and -offset right don't work. Groff does not implement centered and flush-right rendering either, but produces large indentations.

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>.