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Diff for /mandoc/mdoc.7 between version 1.142 and 1.192

version 1.142, 2010/07/26 13:45:49

version 1.192, 2011/07/31 17:30:33

Line 1

.\" $Id$

.\"

.\" Permission to use, copy, modify, and distribute this software for any

Line 28 language is used to format

.Bx

.Ux

manuals.

In this reference document, we describe its syntax, structure, and

This reference document describes its syntax, structure, and

usage.

Our reference implementation is mandoc; the

The reference implementation is

.Xr mandoc 1 ;

the

.Sx COMPATIBILITY

section describes compatibility with other troff \-mdoc implementations.

.Pp

Line 38 An

Line 40 An

.Nm

document follows simple rules: lines beginning with the control

character

.Sq \.

.Sq \&.

are parsed for macros.

Other lines are interpreted within the scope of

Text lines, those not beginning with the control character, are

prior macros:

interpreted within the scope of prior macros:

.Bd -literal -offset indent

\&.Sh Macro lines change control state.

Other lines are interpreted within the current state.

Text lines are interpreted within the current state.

.Ed

.Sh LANGUAGE SYNTAX

.Nm

documents may contain only graphable 7-bit ASCII characters, the space

character, and, in certain circumstances, the tab character.

All manuals must have

.Pp

.Ux

If the first character of a text line is a space, that line is printed

line terminators.

with a leading newline.

.Ss Comments

Text following a

.Sq \e\*q ,

whether in a macro or free-form text line, is ignored to the end of

whether in a macro or text line, is ignored to the end of

line.

A macro line with only a control character and comment escape,

.Sq \&.\e\*q ,

is also ignored.

Macro lines with only a control character and optionally whitespace are

Macro lines with only a control character and optional whitespace are

stripped from input.

.Ss Reserved Characters

.Ss Reserved Terms

Within a macro line, the following characters are reserved:

Within a macro line, the following terms are reserved:

.Pp

.Bl -tag -width Ds -offset indent -compact

.It \&.

.Pq period

.It \e.

.Pq escaped period

.It \&,

.Pq comma

.It \&:

Line 89 Within a macro line, the following characters are rese

Line 93 Within a macro line, the following characters are rese

.Pq exclamation

.It \&|

.Pq vertical bar

.It \e*(Ba

.Pq reserved-word vertical bar

.El

.Pp

Use of reserved characters is described in

For general use in macro lines, these can be escaped with a non-breaking

.Sx MACRO SYNTAX .

space

For general use in macro lines, these characters can either be escaped

.Pq Sq \e& .

with a non-breaking space

In text lines, these may be used as normal punctuation.

.Pq Sq \e&

or, if applicable, an appropriate escape sequence can be used.

.Ss Special Characters

Special characters may occur in both macro and free-form lines.

Special characters may occur in both macro and text lines.

Sequences begin with the escape character

.Sq \e

followed by either an open-parenthesis

Line 107 for two-character sequences; an open-bracket

Line 111 for two-character sequences; an open-bracket

.Sq \&[

for n-character sequences (terminated at a close-bracket

.Sq \&] ) ;

or a single one-character sequence.

or a single one character sequence.

See

.Xr mandoc_char 7

for a complete list.

Line 120 and

Line 124 and

.Ss Text Decoration

Terms may be text-decorated using the

.Sq \ef

escape followed by an indicator: B (bold), I, (italic), R (Roman), or P

escape followed by an indicator: B (bold), I (italic), R (Roman), or P

(revert to previous mode):

.Pp

.D1 \efBbold\efR \efIitalic\efP

.Dl \efBbold\efR \efIitalic\efP

.Pp

A numerical representation 3, 2, or 1 (bold, italic, and Roman,

respectively) may be used instead.

A text decoration is valid within

If a macro opens a font scope after calling

the current font scope only: if a macro opens a font scope alongside

.Sq \ef ,

its own scope, such as

such as with

.Sx \&Bf

.Sx \&Bf ,

.Cm \&Sy ,

the

in-scope invocations of

.Sq \ef

are only valid within the font scope of the macro.

mode will be restored upon exiting the

.Sx \&Bf

.Sq \ef

scope.

is specified outside of any font scope, such as in unenclosed, free-form

text, it will affect the remainder of the document.

.Pp

Note this form is

.Em not

Line 147 recommended for

Line 148 recommended for

which encourages semantic annotation.

.Ss Predefined Strings

Historically,

.Xr groff 1

troff

also defined a set of package-specific

.Dq predefined strings ,

which, like

Line 172 and

Line 173 and

.Pq vertical bar .

.Ss Whitespace

Whitespace consists of the space character.

In free-form lines, whitespace is preserved within a line; un-escaped

In text 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

Blank text lines, which may include whitespace, are only permitted

within literal contexts.

.Pp

In macro lines, whitespace delimits arguments and is discarded.

Line 183 If arguments are quoted, whitespace within the quotes

Line 184 If arguments are quoted, whitespace within the quotes

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 pair-wise adjacent to another double-quote

The next double-quote not pairwise adjacent to another double-quote

terminates the literal, regardless of surrounding whitespace.

.Pp

Note that any quoted text, even if it would cause a macro invocation

Line 194 Thus, the following produces

Line 195 Thus, the following produces

\&.Op "Fl a"

.Ed

.Pp

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

In text lines, quotes are regarded as opaque text.

.Ss Dates

There are several macros in

.Nm

that require a date argument.

The canonical form for dates is the American format:

.Pp

.D1 Cm Month Day , Year

.Pp

The

.Cm Day

value is an optionally zero-padded numeral.

The

.Cm Month

value is the full month name.

The

.Cm Year

value is the full four-digit year.

.Pp

Reduced form dates are broken-down canonical form dates:

.Pp

.D1 Cm Month , Year

.D1 Cm Year

.Pp

Some examples of valid dates follow:

.Pp

.D1 "May, 2009" Pq reduced form

.D1 "2009" Pq reduced form

.D1 "May 20, 2009" Pq canonical form

.Ss Scaling Widths

Many macros support scaled widths for their arguments, such as

stipulating a two-inch list indentation with the following:

Line 276 is necessarily non-portable across output media.

Line 249 is necessarily non-portable across output media.

See

.Sx COMPATIBILITY .

.Ss Sentence Spacing

When composing a manual, make sure that your sentences end at the end of

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 (

delimiters

.Ns Sq \&) ,

.Po

.Sq \&) ,

.Sq \&] ,

.Sq \&' ,

.Sq \&" ) .

.Sq \&"

.Pc .

.Pp

The proper spacing is also intelligently preserved if a sentence ends at

the boundary of a macro line, e.g.,

the boundary of a macro line.

For example:

.Pp

.D1 \&Xr mandoc 1 \.

.Dl \&.Xr mandoc 1 \&.

.D1 \&Fl T \&Ns \&Cm ascii \.

.Dl \&.Fl T \&Ns \&Cm ascii \&.

.Sh MANUAL STRUCTURE

A well-formed

.Nm

Line 320 sections, although this varies between manual sections

Line 296 sections, although this varies between manual sections

.Pp

The following is a well-formed skeleton

.Nm

file:

file for a utility

.Qq progname :

.Bd -literal -offset indent

\&.Dd $\&Mdocdate$

\&.Dt mdoc 7

\&.Dt PROGNAME section

\&.Os

\&.Sh NAME

\&.Nm foo

\&.Nm progname

\&.Nd a description goes here

\&.\e\*q The next is for sections 2, 3, & 9 only.

\&.\e\*q .Sh LIBRARY

\&.\e\*q For sections 2, 3, & 9 only.

\&.\e\*q Not used in OpenBSD.

\&.Sh SYNOPSIS

\&.Nm foo

\&.Nm progname

\&.Op Fl options

\&.Ar

\&.Sh DESCRIPTION

Line 339 The

Line 317 The

\&.Nm

utility processes files ...

\&.\e\*q .Sh IMPLEMENTATION NOTES

\&.\e\*q The next is for sections 2, 3, & 9 only.

\&.\e\*q Not used in OpenBSD.

\&.\e\*q .Sh RETURN VALUES

\&.\e\*q The next is for sections 1, 6, 7, & 8 only.

\&.\e\*q For sections 2, 3, & 9 only.

\&.\e\*q .Sh ENVIRONMENT

\&.\e\*q For sections 1, 6, 7, & 8 only.

\&.\e\*q .Sh FILES

\&.\e\*q The next is for sections 1 & 8 only.

\&.\e\*q .Sh EXIT STATUS

\&.\e\*q For sections 1, 6, & 8 only.

\&.\e\*q .Sh EXAMPLES

\&.\e\*q The next is for sections 1, 4, 6, 7, & 8 only.

\&.\e\*q .Sh DIAGNOSTICS

\&.\e\*q The next is for sections 2, 3, & 9 only.

\&.\e\*q For sections 1, 4, 6, 7, & 8 only.

\&.\e\*q .Sh ERRORS

\&.\e\*q For sections 2, 3, & 9 only.

\&.\e\*q .Sh SEE ALSO

\&.\e\*q .Xr foobar 1

\&.\e\*q .Sh STANDARDS

Line 359 utility processes files ...

Line 338 utility processes files ...

\&.\e\*q .Sh CAVEATS

\&.\e\*q .Sh BUGS

\&.\e\*q .Sh SECURITY CONSIDERATIONS

\&.\e\*q Not used in OpenBSD.

.Ed

.Pp

The sections in a

The sections in an

.Nm

document are conventionally ordered as they appear above.

Sections should be composed as follows:

.Bl -ohang -offset Ds

.It Em NAME

The name(s) and a one-line description of the documented material.

The name(s) and a one line description of the documented material.

The syntax for this as follows:

.Bd -literal -offset indent

\&.Nm name0

\&.Nm name0 ,

\&.Nm name1

\&.Nm name1 ,

\&.Nm name2

\&.Nd a one-line description

\&.Nd a one line description

.Ed

.Pp

Multiple

.Sq \&Nm

names should be separated by commas.

.Pp

The

.Sx \&Nm

macro(s) must precede the

Line 403 configuration.

Line 387 configuration.

For the first, utilities (sections 1, 6, and 8), this is

generally structured as follows:

.Bd -literal -offset indent

\&.Nm foo

\&.Nm bar

\&.Op Fl v

\&.Op Fl o Ar file

\&.Op Ar

\&.Nm bar

\&.Nm foo

\&.Op Fl v

\&.Op Fl o Ar file

\&.Op Ar

.Ed

.Pp

Commands should be ordered alphabetically.

.Pp

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

.Bd -literal -offset indent

\&.Vt extern const char *global;

\&.In header.h

\&.Vt extern const char *global;

\&.Ft "char *"

\&.Fn foo "const char *src"

\&.Ft "char *"

\&.Fn bar "const char *src"

.Ed

.Pp

Ordering of

.Sx \&In ,

.Sx \&Vt ,

.Sx \&Fn ,

and

.Sx \&Fo

macros should follow C header-file conventions.

.Pp

And for the third, configurations (section 4):

.Bd -literal -offset indent

\&.Cd \*qit* at isa? port 0x2e\*q

Line 445 section, particularly

Line 439 section, particularly

and

.Sx \&Ft .

All of these macros are output on their own line.

If two such dissimilar macros are pair-wise invoked (except for

If two such dissimilar macros are pairwise invoked (except for

.Sx \&Ft

before

.Sx \&Fo

Line 471 or

Line 465 or

.Sx \&Ss

macro or the end of an enclosing block, whichever comes first.

.It Em DESCRIPTION

This expands upon the brief, one-line description in

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

.Em NAME .

.Em NAME :

It usually contains a break-down of the options (if documenting a

.Bd -literal -offset indent

The

\&.Nm

utility does this, that, and the other.

.Ed

.Pp

It usually follows with a breakdown of the options (if documenting a

command), such as:

.Bd -literal -offset indent

The arguments are as follows:

Line 489 Implementation-specific notes should be kept here.

This is useful when implementing standard functions that may have side

effects or notable algorithmic implications.

.It Em RETURN VALUES

This section is the dual of

This section documents the

.Em EXIT STATUS ,

return values of functions in sections 2, 3, and 9.

which is used for commands.

It documents the return values of functions in sections 2, 3, and 9.

.Pp

See

.Sx \&Rv .

Line 513 the file is used (created, modified, etc.).

Line 511 the file is used (created, modified, etc.).

See

.Sx \&Pa .

.It Em EXIT STATUS

Command exit status for section 1, 6, and 8 manuals.

This section documents the

This section is the dual of

command exit status for section 1, 6, and 8 utilities.

.Em RETURN VALUES ,

which is used for functions.

Historically, this information was described in

.Em DIAGNOSTICS ,

a practise that is now discouraged.

Line 526 See

Line 522 See

.It Em EXAMPLES

Example usages.

This often contains snippets of well-formed, well-tested invocations.

Make doubly sure that your examples work properly!

Make sure that examples work properly!

.It Em DIAGNOSTICS

Documents error conditions.

This is most useful in section 4 manuals.

Line 560 section should be used instead.

Line 556 section should be used instead.

See

.Sx \&St .

.It Em HISTORY

The history of any manual without a

A brief history of the subject, including where support first appeared.

.Em STANDARDS

section should be described in this section.

.It Em AUTHORS

Credits to authors, if applicable, should appear in this section.

Credits to the person or persons who wrote the code and/or documentation.

Authors should generally be noted by both name and email address.

.Pp

See

Line 573 See

Line 567 See

Common misuses and misunderstandings should be explained

in this section.

.It Em BUGS

Known bugs, limitations and work-arounds should be described

Known bugs, limitations, and work-arounds should be described

in this section.

.It Em SECURITY CONSIDERATIONS

Documents any security precautions that operators should consider.

Line 604 closes it out.

Line 598 closes it out.

.Pp

The

.Em Callable

column indicates that the macro may be called subsequent to the initial

column indicates that the macro may also be called by passing its name

line-macro.

as an argument to another macro.

If a macro is not callable, then its invocation after the initial line

If a macro is not callable but its name appears as an argument

macro is interpreted as opaque text, such that

to another macro, it is interpreted as opaque text.

For example,

.Sq \&.Fl \&Sh

produces

.Sq Fl \&Sh .

.Pp

The

.Em Parsed

column indicates whether the macro may be followed by further

column indicates whether the macro may call other macros by receiving

(ostensibly callable) macros.

their names as arguments.

If a macro is not parsed, subsequent macro invocations on the line

If a macro is not parsed but the name of another macro appears

will be interpreted as opaque text.

as an argument, it is interpreted as opaque text.

.Pp

The

.Em Scope

Line 626 column, if applicable, describes closure rules.

Line 621 column, if applicable, describes closure rules.

Multi-line scope closed by an explicit closing macro.

All macros contains bodies; only

.Sx \&Bf

contains a head.

and

.Pq optionally

.Sx \&Bl

contain a head.

.Bd -literal -offset indent

\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB

\(lBbody...\(rB

Line 731 and/or tail

Line 729 and/or tail

.El

.Ss Block partial-implicit

Like block full-implicit, but with single-line scope closed by

.Sx Reserved Characters

.Sx Reserved Terms

or end of line.

.Bd -literal -offset indent

\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB

Line 762 in a

Line 760 in a

.Em SYNOPSIS

section line, else it is

.Sx In-line .

.Ss Special block macro

The

.Sx \&Ta

macro can only be used below

.Sx \&It

.Sx \&Bl Fl column

lists.

It delimits blocks representing table cells;

these blocks have bodies, but no heads.

.Pp

.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -compact -offset indent

.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope

.It Sx \&Ta Ta Yes Ta Yes Ta closed by Sx \&Ta , Sx \&It

.El

.Ss In-line

Closed by

.Sx Reserved Characters ,

.Sx 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

.Pq n ,

then the macro accepts an arbitrary number of arguments.

.Bd -literal -offset indent

\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lbres...\(rb

\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lBres...\(rB

\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...

Line 794 then the macro accepts an arbitrary number of argument

Line 807 then the macro accepts an arbitrary number of argument

.It Sx \&%T Ta \&No Ta \&No Ta >0

.It Sx \&%U Ta \&No Ta \&No Ta >0

.It Sx \&%V Ta \&No Ta \&No Ta >0

.It Sx \&Ad Ta Yes Ta Yes Ta n

.It Sx \&Ad Ta Yes Ta Yes Ta >0

.It Sx \&An Ta Yes Ta Yes Ta n

.It Sx \&An Ta Yes Ta Yes Ta >0

.It Sx \&Ap Ta Yes Ta Yes Ta 0

.It Sx \&Ar Ta Yes Ta Yes Ta n

.It Sx \&At Ta Yes Ta Yes Ta 1

Line 803 then the macro accepts an arbitrary number of argument

Line 816 then the macro accepts an arbitrary number of argument

.It Sx \&Bt Ta \&No Ta \&No Ta 0

.It Sx \&Bx Ta Yes Ta Yes Ta n

.It Sx \&Cd Ta Yes Ta Yes Ta >0

.It Sx \&Cm Ta Yes Ta Yes Ta n

.It Sx \&Cm Ta Yes Ta Yes Ta >0

.It Sx \&Db Ta \&No Ta \&No Ta 1

.It Sx \&Dd Ta \&No Ta \&No Ta n

.It Sx \&Dt Ta \&No Ta \&No Ta n

.It Sx \&Dv Ta Yes Ta Yes Ta n

.It Sx \&Dv Ta Yes Ta Yes Ta >0

.It Sx \&Dx Ta Yes Ta Yes Ta n

.It Sx \&Em Ta Yes Ta Yes Ta >0

.It Sx \&En Ta \&No Ta \&No Ta 0

.It Sx \&Er Ta Yes Ta Yes Ta >0

.It Sx \&Es Ta \&No Ta \&No Ta 0

.It Sx \&Ev Ta Yes Ta Yes Ta n

.It Sx \&Ev Ta Yes Ta Yes Ta >0

.It Sx \&Ex Ta \&No Ta \&No Ta n

.It Sx \&Fa Ta Yes Ta Yes Ta n

.It Sx \&Fa Ta Yes Ta Yes Ta >0

.It Sx \&Fd Ta \&No Ta \&No Ta >0

.It Sx \&Fl Ta Yes Ta Yes Ta n

.It Sx \&Fn Ta Yes Ta Yes Ta >0

.It Sx \&Fr Ta \&No Ta \&No Ta n

.It Sx \&Ft Ta Yes Ta Yes Ta n

.It Sx \&Ft Ta Yes Ta Yes Ta >0

.It Sx \&Fx Ta Yes Ta Yes Ta n

.It Sx \&Hf Ta \&No Ta \&No Ta n

.It Sx \&Ic Ta Yes Ta Yes Ta >0

.It Sx \&In Ta \&No Ta \&No Ta n

.It Sx \&In Ta \&No Ta \&No Ta 1

.It Sx \&Lb Ta \&No Ta \&No Ta 1

.It Sx \&Li Ta Yes Ta Yes Ta n

.It Sx \&Li Ta Yes Ta Yes Ta >0

.It Sx \&Lk Ta Yes Ta Yes Ta n

.It Sx \&Lk Ta Yes Ta Yes Ta >0

.It Sx \&Lp Ta \&No Ta \&No Ta 0

.It Sx \&Ms Ta Yes Ta Yes Ta >0

.It Sx \&Mt Ta Yes Ta Yes Ta >0

Line 879 referring to book titles.

Line 892 referring to book titles.

Publication city or location of an

.Sx \&Rs

block.

.Pp

.Em Remarks :

this macro is not implemented in

.Xr groff 1 .

.Ss \&%D

Publication date of an

.Sx \&Rs

block.

This should follow the reduced or canonical form syntax described in

Recommended formats of arguments are

.Sx Dates .

.Ar month day , year

or just

.Ar year .

.Ss \&%I

Publisher or issuer name of an

.Sx \&Rs

Line 942 Memory address.

Line 953 Memory address.

Do not use this for postal addresses.

.Pp

Examples:

.D1 \&.Ad [0,$]

.Dl \&.Ad [0,$]

.D1 \&.Ad 0x00000000

.Dl \&.Ad 0x00000000

.Ss \&An

Author name.

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

Line 973 for the first author listing and

Line 984 for the first author listing and

for all other author listings.

.Pp

Examples:

.D1 \&.An -nosplit

.Dl \&.An -nosplit

.D1 \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv

.Dl \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv

.Ss \&Ao

Begin a block enclosed by angle brackets.

Does not have any head arguments.

.Pp

Examples:

.D1 \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac

.Dl \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac

.Pp

See also

.Sx \&Aq .

Line 990 This is generally used as a grammatical device when re

Line 1001 This is generally used as a grammatical device when re

form of a function.

.Pp

Examples:

.D1 \&.Fn execve \&Ap d

.Dl \&.Fn execve \&Ap d

.Ss \&Aq

Encloses its arguments in angle brackets.

.Pp

Examples:

.D1 \&.Fl -key= \&Ns \&Aq \&Ar val

.Dl \&.Fl -key= \&Ns \&Aq \&Ar val

.Pp

.Em Remarks :

this macro is often abused for rendering URIs, which should instead use

Line 1016 If an argument is not provided, the string

Line 1027 If an argument is not provided, the string

is used as a default.

.Pp

Examples:

.D1 \&.Fl o \&Ns \&Ar file1

.Dl \&.Fl o \&Ns \&Ar file1

.D1 \&.Ar

.Dl \&.Ar

.D1 \&.Ar arg1 , arg2 .

.Dl \&.Ar arg1 , arg2 .

.Ss \&At

Formats an AT&T version.

Accepts one optional argument:

Line 1027 Accepts one optional argument:

Line 1038 Accepts one optional argument:

.It Cm v[1-7] | 32v

A version of

.At .

.It Cm III

.At III .

.It Cm V[.[1-4]]?

A version of

.At V .

Line 1035 A version of

Line 1048 A version of

Note that these arguments do not begin with a hyphen.

.Pp

Examples:

.D1 \&.At

.Dl \&.At

.D1 \&.At V.1

.Dl \&.At III

.Dl \&.At V.1

.Pp

See also

.Sx \&Bsx ,

Line 1064 Its syntax is as follows:

Line 1078 Its syntax is as follows:

.Pp

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.

They may contain both macro lines and text lines.

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

.Pp

The

Line 1161 and

Line 1175 and

argument are equivalent, as are

.Fl symbolic

and

.Cm \&Sy,

.Cm \&Sy ,

and

.Fl literal

and

Line 1179 See also

Line 1193 See also

and

.Sx \&Sy .

.Ss \&Bk

Keep the output generated from each macro input line together

For each macro, keep its output together on the same output line,

on one single output line.

until the end of the macro or the end of the input line is reached,

Line breaks in free-form text lines are unaffected.

whichever comes first.

Line breaks in text lines are unaffected.

The syntax is as follows:

.Pp

.D1 Pf \. Sx \&Bk Fl words

Line 1204 Be careful in using over-long lines within a keep bloc

Line 1219 Be careful in using over-long lines within a keep bloc

Doing so will clobber the right margin.

.Ss \&Bl

Begin a list.

Lists consist of items started by the

Lists consist of items specified using the

.Sx \&It

macro, containing a head or a body or both.

The list syntax is as follows:

Line 1339 See also

Line 1354 See also

Encloses its arguments in square brackets.

.Pp

Examples:

.D1 \&.Bq 1 , \&Dv BUFSIZ

.Dl \&.Bq 1 , \&Dv BUFSIZ

.Pp

.Em Remarks :

this macro is sometimes abused to emulate optional arguments for

Line 1372 See also

Line 1387 See also

Encloses its arguments in curly braces.

.Pp

Examples:

.D1 \&.Brq 1 , ... , \&Va n

.Dl \&.Brq 1 , ... , \&Va n

.Pp

See also

.Sx \&Bro .

Line 1381 Format the BSD/OS version provided as an argument, or

Line 1396 Format the BSD/OS version provided as an argument, or

no argument is provided.

.Pp

Examples:

.D1 \&.Bsx 1.0

.Dl \&.Bsx 1.0

.D1 \&.Bsx

.Dl \&.Bsx

.Pp

See also

.Sx \&At ,

Line 1395 and

Line 1410 and

.Sx \&Ux .

.Ss \&Bt

Prints

.Dq is currently in beta test.

.Dq is currently in beta test .

.Ss \&Bx

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

argument is provided.

.Pp

Examples:

.D1 \&.Bx 4.4

.Dl \&.Bx 4.4

.D1 \&.Bx

.Dl \&.Bx

.Pp

See also

.Sx \&At ,

Line 1419 This denotes strings accepted by

Line 1434 This denotes strings accepted by

.Xr config 8 .

.Pp

Examples:

.D1 \&.Cd device le0 at scode?

.Dl \&.Cd device le0 at scode?

.Pp

.Em Remarks :

this macro is commonly abused by using quoted literals to retain

Line 1432 Command modifiers.

Line 1447 Command modifiers.

Useful when specifying configuration options or keys.

.Pp

Examples:

.D1 \&.Cm ControlPath

.Dl \&.Cm ControlPath

.D1 \&.Cm ControlMaster

.Dl \&.Cm ControlMaster

.Pp

See also

.Sx \&Fl .

Line 1444 statements.

Line 1459 statements.

It is followed by a newline.

.Pp

Examples:

.D1 \&.D1 \&Fl abcdefgh

.Dl \&.D1 \&Fl abcdefgh

.Pp

See also

.Sx \&Bd

Line 1470 This is the mandatory first macro of any

Line 1485 This is the mandatory first macro of any

manual.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Dd Op Ar date

.D1 Pf \. Sx \&Dd Ar month day , year

.Pp

The

.Ar date

.Ar month

may be either

is the full English month name, the

.Ar $\&Mdocdate$ ,

.Ar day

which signifies the current manual revision date dictated by

is an optionally zero-padded numeral, and the

.Ar year

is the full four-digit year.

.Pp

Other arguments are not portable; the

.Xr mandoc 1

utility handles them as follows:

.Bl -dash -offset 3n -compact

.It

To have the date automatically filled in by the

.Ox

version of

.Xr cvs 1 ,

or instead a valid canonical date as specified by

the special string

.Sx Dates .

.Dq $\&Mdocdate$

If a date does not conform or is empty, the current date is used.

can be given as an argument.

.It

A few alternative date formats are accepted as well

and converted to the standard form.

.It

If a date string cannot be parsed, it is used verbatim.

.It

If no date string is given, the current date is used.

.El

.Pp

Examples:

.D1 \&.Dd $\&Mdocdate$

.Dl \&.Dd $\&Mdocdate$

.D1 \&.Dd $\&Mdocdate: July 21 2007$

.Dl \&.Dd $\&Mdocdate: July 21 2007$

.D1 \&.Dd July 21, 2007

.Dl \&.Dd July 21, 2007

.Pp

See also

.Sx \&Dt

Line 1498 invocations.

Line 1532 invocations.

It is followed by a newline.

.Pp

Examples:

.D1 \&.Dl % mandoc mdoc.7 \e(ba less

.Dl \&.Dl % mandoc mdoc.7 \e(ba less

.Pp

See also

.Sx \&Bd

Line 1650 It must be one of

Line 1684 It must be one of

.Ar luna88k ,

.Ar mac68k ,

.Ar macppc ,

.Ar mips64 ,

.Ar mvme68k ,

.Ar mvme88k ,

.Ar mvmeppc ,

Line 1665 or

Line 1700 or

.El

.Pp

Examples:

.D1 \&.Dt FOO 1

.Dl \&.Dt FOO 1

.D1 \&.Dt FOO 4 KM

.Dl \&.Dt FOO 4 KM

.D1 \&.Dt FOO 9 i386

.Dl \&.Dt FOO 9 i386

.Pp

See also

.Sx \&Dd

and

.Sx \&Os .

.Ss \&Dv

Defined variables such as preprocessor constants.

Defined variables such as preprocessor constants, constant symbols,

enumeration values, and so on.

.Pp

Examples:

.D1 \&.Dv BUFSIZ

.Dl \&.Dv NULL

.D1 \&.Dv STDOUT_FILENO

.Dl \&.Dv BUFSIZ

.Dl \&.Dv STDOUT_FILENO

.Pp

See also

.Sx \&Er .

.Sx \&Er

and

.Sx \&Ev

for special-purpose constants and

.Sx \&Va

for variable symbols.

.Ss \&Dx

Format the DragonFly BSD version provided as an argument, or a default

value if no argument is provided.

.Pp

Examples:

.D1 \&.Dx 2.4.1

.Dl \&.Dx 2.4.1

.D1 \&.Dx

.Dl \&.Dx

.Pp

See also

.Sx \&At ,

Line 1734 Note that this is a presentation term and should not b

Line 1776 Note that this is a presentation term and should not b

stylistically decorating technical terms.

.Pp

Examples:

.D1 \&.Em Warnings!

.Dl \&.Em Warnings!

.D1 \&.Em Remarks :

.Dl \&.Em Remarks :

.Pp

See also

.Sx \&Bf ,

Line 1757 argument is used as the enclosure head, for example, s

Line 1799 argument is used as the enclosure head, for example, s

will emulate

.Sx \&Do .

.Ss \&Er

Display error constants.

Error constants for definitions of the

.Va errno

libc global variable.

.Pp

Examples:

.D1 \&.Er EPERM

.Dl \&.Er EPERM

.D1 \&.Er ENOENT

.Dl \&.Er ENOENT

.Pp

See also

.Sx \&Dv .

.Sx \&Dv

for general constants.

.Ss \&Es

This macro is obsolete and not implemented.

.Ss \&Ev

Line 1772 Environmental variables such as those specified in

Line 1817 Environmental variables such as those specified in

.Xr environ 7 .

.Pp

Examples:

.D1 \&.Ev DISPLAY

.Dl \&.Ev DISPLAY

.D1 \&.Ev PATH

.Dl \&.Ev PATH

.Pp

See also

.Sx \&Dv

for general constants.

.Ss \&Ex

Insert a standard sentence regarding exit values.

Insert a standard sentence regarding command exit values of 0 on success

and >0 on failure.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Ex Fl std Op Ar utility

.D1 Pf \. Sx \&Ex Fl std Op Ar utility...

.Pp

When

.Ar utility

is not specified, the document's name set by

.Sx \&Nm

is used.

Multiple

.Ar utility

arguments are treated as separate utilities.

.Pp

See also

.Sx \&Rv .

Line 1813 Furthermore, if the following macro is another

Line 1866 Furthermore, if the following macro is another

the last argument will also have a trailing comma.

.Pp

Examples:

.D1 \&.Fa \(dqconst char *p\(dq

.Dl \&.Fa \(dqconst char *p\(dq

.D1 \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq

.Dl \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq

.D1 \&.Fa foo

.Dl \&.Fa foo

.Pp

See also

.Sx \&Fo .

Line 1843 If the argument is a macro, a hyphen is prefixed to th

Line 1896 If the argument is a macro, a hyphen is prefixed to th

output.

.Pp

Examples:

.D1 \&.Fl a b c

.Dl \&.Fl a b c

.D1 \&.Fl \&Pf a b

.Dl \&.Fl \&Pf a b

.D1 \&.Fl

.Dl \&.Fl

.D1 \&.Op \&Fl o \&Ns \&Ar file

.Dl \&.Op \&Fl o \&Ns \&Ar file

.Pp

See also

.Sx \&Cm .

Line 1855 A function name.

Line 1908 A function name.

Its syntax is as follows:

.Bd -ragged -offset indent

.Pf \. Ns Sx \&Fn

.Op Cm functype

.Op Ar functype

.Cm funcname

.Ar funcname

.Op Oo Cm argtype Oc Cm argname

.Op Oo Ar argtype Oc Ar argname

.Ed

.Pp

Function arguments are surrounded in parenthesis and

Line 1865 are delimited by commas.

Line 1918 are delimited by commas.

If no arguments are specified, blank parenthesis are output.

.Pp

Examples:

.D1 \&.Fn "int funcname" "int arg0" "int arg1"

.Dl \&.Fn \*qint funcname\*q \*qint arg0\*q \*qint arg1\*q

.D1 \&.Fn funcname "int arg0"

.Dl \&.Fn funcname \*qint arg0\*q

.D1 \&.Fn funcname arg0

.Dl \&.Fn funcname arg0

.Bd -literal -offset indent -compact

\&.Ft functype

\&.Fn funcname

.Ed

.Pp

When referring to a function documented in another manual page, use

.Sx \&Xr

instead.

See also

.Sx MANUAL STRUCTURE

and

Line 1883 This is a multi-line version of

Line 1939 This is a multi-line version of

.Sx \&Fn .

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Fo Cm funcname

.D1 Pf \. Sx \&Fo Ar funcname

.Pp

Invocations usually occur in the following context:

.Bd -ragged -offset indent

.Pf \. Sx \&Ft Cm functype

.Pf \. Sx \&Ft Ar functype

.br

.Pf \. Sx \&Fo Cm funcname

.Pf \. Sx \&Fo Ar funcname

.br

.Pf \. Sx \&Fa Oo Cm argtype Oc Cm argname

.Pf \. Sx \&Fa Oo Ar argtype Oc Ar argname

.br

\.\.\.

\&.\.\.

.br

.Pf \. Sx \&Fc

.Ed

Line 1908 See also

Line 1964 See also

.Sx \&Fc ,

and

.Sx \&Ft .

.Ss \&Fr

This macro is obsolete and not implemented.

.Ss \&Ft

A function type.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Ft Cm functype

.D1 Pf \. Sx \&Ft Ar functype

.Pp

Examples:

.D1 \&.Ft int

.Dl \&.Ft int

.Bd -literal -offset indent -compact

\&.Ft functype

\&.Fn funcname

Line 1927 See also

Line 1985 See also

and

.Sx \&Fo .

.Ss \&Fx

Format the FreeBSD version provided as an argument, or a default value

Format the

.Fx

version provided as an argument, or a default value

if no argument is provided.

.Pp

Examples:

.D1 \&.Fx 7.1

.Dl \&.Fx 7.1

.D1 \&.Fx

.Dl \&.Fx

.Pp

See also

.Sx \&At ,

Line 1952 This is similar to

Line 2012 This is similar to

but used for instructions rather than values.

.Pp

Examples:

.D1 \&.Ic hash

.Dl \&.Ic hash

.D1 \&.Ic alias

.Dl \&.Ic alias

.Pp

Note that using

.Sx \&Bd No Fl literal

.Sx \&Bd Fl literal

.Sx \&D1

is preferred for displaying code; the

Line 1974 preceded by

Line 2034 preceded by

the arguments is enclosed in angle brackets.

.Pp

Examples:

.D1 \&.In sys/types

.Dl \&.In sys/types

.Pp

See also

.Sx MANUAL STRUCTURE .

Line 1991 and

Line 2051 and

.Fl diag

have the following syntax:

.Pp

.D1 Pf \. Sx \&It Cm args

.D1 Pf \. Sx \&It Ar args

.Pp

Lists of type

.Fl bullet ,

Line 2028 The

Line 2088 The

list is the most complicated.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&It Op Cm args

.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...

.D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...

.Pp

The

The arguments consist of one or more lines of text and macros

.Cm args

representing a complete table line.

are phrases, a mix of macros and text corresponding to a line column,

Cells within the line are delimited by tabs or by the special

delimited by tabs or the special

.Sx \&Ta

.Sq \&Ta

block macro.

pseudo-macro.

The tab cell delimiter may only be used within the

Lines subsequent the

.Sx \&It

are interpreted within the scope of the last phrase.

line itself; on following lines, only the

Calling the pseudo-macro

.Sx \&Ta

.Sq \&Ta

macro can be used to delimit cells, and

will open a new phrase scope (this must occur on a macro line to be

.Sx \&Ta

interpreted as a macro).

is only recognized as a macro when called by other macros,

Note that the tab phrase delimiter may only be used within the

not as the first macro on a line.

.Pp

Note that quoted strings may span tab-delimited cells on an

.Sx \&It

line itself.

line.

Subsequent this, only the

For example,

.Sq \&Ta

pseudo-macro may be used to delimit phrases.

Furthermore, note that quoted sections propagate over tab-delimited

phrases on an

.Sx \&It ,

for example,

.Pp

.D1 .It \(dqcol1 ; <TAB> col2 ;\(dq \&;

.Dl .It \(dqcol1 ; <TAB> col2 ;\(dq \&;

.Pp

will preserve the semicolon whitespace except for the last.

.Pp

Line 2064 See also

Line 2120 See also

Specify a library.

The syntax is as follows:

.Pp

.D1 Pf \. Sx \&Lb Cm library

.D1 Pf \. Sx \&Lb Ar library

.Pp

The

.Cm library

.Ar library

parameter may be a system library, such as

.Cm libz

.Ar libz

.Cm libpam ,

.Ar 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.

Line 2081 section as described in

Line 2137 section as described in

.Sx MANUAL STRUCTURE .

.Pp

Examples:

.D1 \&.Lb libz

.Dl \&.Lb libz

.D1 \&.Lb mdoc

.Dl \&.Lb mdoc

.Ss \&Li

Denotes text that should be in a literal font mode.

Note that this is a presentation term and should not be used for

Line 2097 and

Line 2153 and

Format a hyperlink.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Lk Cm uri Op Cm name

.D1 Pf \. Sx \&Lk Ar uri Op Ar name

.Pp

Examples:

.D1 \&.Lk http://bsd.lv "The BSD.lv Project"

.Dl \&.Lk http://bsd.lv \*qThe BSD.lv Project\*q

.D1 \&.Lk http://bsd.lv

.Dl \&.Lk http://bsd.lv

.Pp

See also

.Sx \&Mt .

Line 2112 Synonym for

Line 2168 Synonym for

Display a mathematical symbol.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Ms Cm symbol

.D1 Pf \. Sx \&Ms Ar symbol

.Pp

Examples:

.D1 \&.Ms sigma

.Dl \&.Ms sigma

.D1 \&.Ms aleph

.Dl \&.Ms aleph

.Ss \&Mt

Format a

.Dq mailto:

hyperlink.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Mt Cm address

.D1 Pf \. Sx \&Mt Ar address

.Pp

Examples:

.D1 \&.Mt discuss@manpages.bsd.lv

.Dl \&.Mt discuss@manpages.bsd.lv

.Ss \&Nd

A one-line description of the manual's content.

A one line description of the manual's content.

This may only be invoked in the

.Em SYNOPSIS

section subsequent the

Line 2136 section subsequent the

Line 2192 section subsequent the

macro.

.Pp

Examples:

.D1 \&.Sx \&Nd mdoc language reference

.Dl \&.Sx \&Nd mdoc language reference

.D1 \&.Sx \&Nd format and display UNIX manuals

.Dl \&.Sx \&Nd format and display UNIX manuals

.Pp

The

.Sx \&Nd

Line 2194 A

Line 2250 A

macro used to terminate prior macro contexts.

.Pp

Examples:

.D1 \&.Sx \&Fl ab \&No cd \&Fl ef

.Dl \&.Sx \&Fl ab \&No cd \&Fl ef

.Ss \&Ns

Suppress a space.

Following invocation, text is interpreted as free-form text until a

macro is encountered.

.Pp

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

.Pp

Examples:

.D1 \&.Fl o \&Ns \&Ar output

.Dl \&.Fl o \&Ns \&Ar output

.Pp

See also

.Sx \&No

and

.Sx \&Sm .

.Ss \&Nx

Format the NetBSD version provided as an argument, or a default value if

Format the

.Nx

version provided as an argument, or a default value if

no argument is provided.

.Pp

Examples:

.D1 \&.Nx 5.01

.Dl \&.Nx 5.01

.D1 \&.Nx

.Dl \&.Nx

.Pp

See also

.Sx \&At ,

Line 2244 Used when listing options to command-line utilities.

Line 2304 Used when listing options to command-line utilities.

Prints the argument(s) in brackets.

.Pp

Examples:

.D1 \&.Op \&Fl a \&Ar b

.Dl \&.Op \&Fl a \&Ar b

.D1 \&.Op \&Ar a | b

.Dl \&.Op \&Ar a | b

.Pp

See also

.Sx \&Oo .

Line 2257 any

Line 2317 any

file.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Os Op Cm system

.D1 Pf \. Sx \&Os Op Ar system Op Ar version

.Pp

The optional

.Cm system

.Ar system

parameter specifies the relevant operating system or environment.

Left unspecified, it defaults to the local operating system version.

This is the suggested form.

.Pp

Examples:

.D1 \&.Os

.Dl \&.Os

.D1 \&.Os KTH/CSC/TCS

.Dl \&.Os KTH/CSC/TCS

.D1 \&.Os BSD 4.3

.Dl \&.Os BSD 4.3

.Pp

See also

.Sx \&Dd

Line 2280 Unknown usage.

Line 2340 Unknown usage.

.Em Remarks :

this macro has been deprecated.

.Ss \&Ox

Format the OpenBSD version provided as an argument, or a default value

Format the

.Ox

version provided as an argument, or a default value

if no argument is provided.

.Pp

Examples:

.D1 \&.Ox 4.5

.Dl \&.Ox 4.5

.D1 \&.Ox

.Dl \&.Ox

.Pp

See also

.Sx \&At ,

Line 2298 and

Line 2360 and

.Sx \&Ux .

.Ss \&Pa

A file-system path.

If an argument is not provided, the string

.Dq \(ti

is used as a default.

.Pp

Examples:

.D1 \&.Pa /usr/bin/mandoc

.Dl \&.Pa /usr/bin/mandoc

.D1 \&.Pa /usr/share/man/man7/mdoc.7

.Dl \&.Pa /usr/share/man/man7/mdoc.7

.Pp

See also

.Sx \&Lk .

Line 2314 Removes the space

Line 2379 Removes the space

between its arguments.

Its syntax is as follows:

.Pp

.D1 Pf \. \&Pf Cm prefix suffix

.D1 Pf \. \&Pf Ar prefix suffix

.Pp

The

.Cm suffix

.Ar suffix

argument may be a macro.

.Pp

Examples:

.D1 \&.Pf \e. \&Sx \&Pf \&Cm prefix suffix

.Dl \&.Pf \e. \&Sx \&Pf \&Ar prefix suffix

.Ss \&Po

Multi-line version of

.Sx \&Pq .

Line 2404 block is used within a SEE ALSO section, a vertical sp

Line 2469 block is used within a SEE ALSO section, a vertical sp

before the rendered output, else the block continues on the current

line.

.Ss \&Rv

Inserts text regarding a function call's return value.

Insert a standard sentence regarding a system call's return value of 0

This macro must consist of the

on success and \-1 on error, with the

.Fl std

.Va errno

argument followed by an optional

libc global variable set on error.

.Ar function .

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Rv Fl std Op Ar function...

.Pp

.Ar function

is not provided, the document's name as stipulated by the first

is not specified, the document's name set by

.Sx \&Nm

is provided.

is used.

Multiple

.Ar function

arguments are treated as separate functions.

.Pp

See also

.Sx \&Ex .

Line 2442 Its syntax is as follows:

Line 2513 Its syntax is as follows:

.D1 Pf \. Sx \&Sm Cm on | off

.Pp

By default, spacing is

.Cm on .

.Ar on .

When switched

.Cm off ,

.Ar off ,

no white space is inserted between macro arguments and between the

output generated from adjacent macros, but free-form text lines

output generated from adjacent macros, but text lines

still get normal spacing between words and sentences.

.Ss \&So

Multi-line version of

Line 2581 The referenced section or sub-section name must be ide

Line 2652 The referenced section or sub-section name must be ide

enclosed argument, including whitespace.

.Pp

Examples:

.D1 \&.Sx MANUAL STRUCTURE

.Dl \&.Sx MANUAL STRUCTURE

.Pp

See also

.Sx \&Sh

and

.Sx \&Ss .

.Ss \&Sy

Format enclosed arguments in symbolic

.Pq Dq boldface .

Line 2593 See also

Line 2669 See also

.Sx \&Li ,

and

.Sx \&Em .

.Ss \&Ta

Table cell separator in

.Sx \&Bl Fl column

lists; can only be used below

.Sx \&It .

.Ss \&Tn

Format a tradename.

.Pp

Examples:

.D1 \&.Tn IBM

.Dl \&.Tn IBM

.Ss \&Ud

Prints out

.Dq currently under development.

.Dq currently under development .

.Ss \&Ux

Format the UNIX name.

Accepts no argument.

.Pp

Examples:

.D1 \&.Ux

.Dl \&.Ux

.Pp

See also

.Sx \&At ,

Line 2621 and

Line 2702 and

A variable name.

.Pp

Examples:

.D1 \&.Va foo

.Dl \&.Va foo

.D1 \&.Va const char *bar ;

.Dl \&.Va const char *bar ;

.Ss \&Vt

A variable type.

This is also used for indicating global variables in the

Line 2641 Note that this should not be confused with

Line 2722 Note that this should not be confused with

which is used for function return types.

.Pp

Examples:

.D1 \&.Vt unsigned char

.Dl \&.Vt unsigned char

.D1 \&.Vt extern const char * const sys_signame[] \&;

.Dl \&.Vt extern const char * const sys_signame[] \&;

.Pp

See also

.Sx MANUAL STRUCTURE

Line 2652 and

Line 2733 and

Close a scope opened by

.Sx \&Xo .

.Ss \&Xo

Open an extension scope.

Extend the header of an

This macro originally existed to extend the 9-argument limit of troff;

.Sx \&It

since this limit has been lifted, the macro has been deprecated.

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

.Xr roff 7 .

.Ss \&Xr

Link to another manual

.Pq Qq cross-reference .

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&Xr Cm name section

.D1 Pf \. Sx \&Xr Ar name section

.Pp

The

.Cm name

.Ar name

and

.Cm section

.Ar section

are the name and section of the linked manual.

.Cm section

.Ar section

is followed by non-punctuation, an

.Sx \&Ns

is inserted into the token stream.

This behaviour is for compatibility with

.Xr groff 1 .

GNU troff.

.Pp

Examples:

.D1 \&.Xr mandoc 1

.Dl \&.Xr mandoc 1

.D1 \&.Xr mandoc 1 \&;

.Dl \&.Xr mandoc 1 \&;

.D1 \&.Xr mandoc 1 \&Ns s behaviour

.Dl \&.Xr mandoc 1 \&Ns s behaviour

.Ss \&br

Emits a line-break.

This macro should not be used; it is implemented for compatibility with

Line 2693 This macro should not be used; it is implemented for c

Line 2778 This macro should not be used; it is implemented for c

historical manuals.

Its syntax is as follows:

.Pp

.D1 Pf \. Sx \&sp Op Cm height

.D1 Pf \. Sx \&sp Op Ar height

.Pp

The

.Cm height

.Ar height

argument must be formatted as described in

.Sx Scaling Widths .

If unspecified,

Line 2708 troff implementations, at this time limited to GNU tro

Line 2793 troff implementations, at this time limited to GNU tro

.Pq Qq groff .

The term

.Qq historic groff

refers to groff versions before the

refers to groff versions before 1.17,

which featured a significant update of the

.Pa doc.tmac

file re-write

file.

.Pq somewhere between 1.15 and 1.19 .

.Pp

Heirloom troff, the other significant troff implementation accepting

\-mdoc, is similar to historic groff.

.Pp

The following problematic behaviour is found in groff:

.ds hist (Historic groff only.)

.Pp

.Bl -dash -compact

.It

An empty

Display macros

.Sq \&Dd

.Po

macro in groff prints

.Sx \&Bd ,

.Dq Epoch .

.Sx \&Dl ,

In mandoc, it resolves to the current date.

and

.Sx \&D1

.Pc

may not be nested.

\*[hist]

.It

The \es (font size), \em (font colour), and \eM (font filling colour)

.Sx \&At

font decoration escapes are all discarded in mandoc.

with unknown arguments produces no output at all.

\*[hist]

Newer groff and mandoc print

.Qq AT&T UNIX

and the arguments.

.It

Old groff fails to assert a newline before

.Sx \&Bl Fl column

.Sx \&Bd Fl ragged compact .

does not recognize trailing punctuation characters when they immediately

precede tabulator characters, but treats them as normal text and

outputs a space before them.

.It

groff behaves inconsistently when encountering

.Sx \&Bd Fl ragged compact

.Pf non- Sx \&Fa

does not start a new line.

children of

\*[hist]

.It

.Sx \&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

.Dq Epoch

is printed.

.It

.Sx \&Fl

does not print a dash for an empty argument.

\*[hist]

.It

.Sx \&Fn

does not start a new line unless invoked as the line macro in the

.Em SYNOPSIS

section.

\*[hist]

.It

.Sx \&Fo

regarding spacing between arguments.

with

In mandoc, this is not the case: each argument is consistently followed

.Pf non- Sx \&Fa

by a single space and the trailing

children causes inconsistent spacing between arguments.

.Sq \&)

In mandoc, a single space is always inserted between arguments.

suppresses prior spacing.

.It

groff behaves inconsistently when encountering

.Sx \&Ft

and

.Sx \&Fn

in the

.Em SYNOPSIS :

.Em SYNOPSIS

at times newline(s) are suppressed depending on whether a prior

causes inconsistent vertical spacing, depending on whether a prior

.Sx \&Fn

has been invoked.

In mandoc, this is not the case.

See

.Sx \&Ft

and

.Sx \&Fn

for the normalised behaviour.

for the normalised behaviour in mandoc.

.It

Historic groff does not break before an

.Sx \&Fn

when not invoked as the line macro in the

.Em SYNOPSIS

section.

.It

Historic groff formats the

.Sx \&In

badly: trailing arguments are trashed and

ignores additional arguments and is not treated specially in the

.Em SYNOPSIS

.Em SYNOPSIS .

is not specially treated.

\*[hist]

.It

groff does not accept the

.Sx \&It

.Sq \&Ta

sometimes requires a

pseudo-macro as a line macro.

.Fl nested

mandoc does.

flag.

\*[hist]

In new groff and mandoc, any list may be nested by default and

.Fl enum

lists will restart the sequence only for the sub-list.

.It

The comment syntax

.Sx \&Li

.Sq \e\."

followed by a reserved character is incorrectly used in some manuals

is no longer accepted.

instead of properly quoting that character, which sometimes works with

historic groff.

.It

In groff, the

.Sx \&Lk

only accepts a single link-name argument; the remainder is misformatted.

.It

.Sx \&Pa

macro does not format its arguments when used in the FILES section under

does not format its arguments when used in the FILES section under

certain list types.

mandoc does.

.It

Historic groff does not print a dash for empty

.Sx \&Ta

.Sx \&Fl

can only be called by other macros, but not at the beginning of a line.

arguments.

mandoc and newer groff implementations do.

.It

groff behaves irregularly when specifying

.Sx \&%C

is not implemented.

.It

Historic groff only allows up to eight or nine arguments per macro input

line, depending on the exact situation.

Providing more arguments causes garbled output.

The number of arguments on one input line is not limited with mandoc.

.It

Historic groff has many un-callable macros.

Most of these (excluding some block-level macros) are callable

in new groff and mandoc.

.It

.Sq \(ba

(vertical bar) is not fully supported as a delimiter.

\*[hist]

.It

.Sq \ef

.Pq font face

and

.Sq \ef

.Pq font family face

.Sx Text Decoration

within line-macro scopes.

escapes behave irregularly when specified within line-macro scopes.

mandoc follows a consistent system.

.It

In mandoc, negative scaling units are truncated to zero; groff would

Negative scaling units return to prior lines.

move to prior lines.

Instead, mandoc truncates them to zero.

Furthermore, the

.El

.Sq f

.Pp

scaling unit, while accepted, is rendered as the default unit.

The following features are unimplemented in mandoc:

.Pp

.Bl -dash -compact

.It

In quoted literals, groff allowed pair-wise double-quotes to produce a

.Sx \&Bd

standalone double-quote in formatted output.

.Fl file Ar file .

This idiosyncratic behaviour is not applicable in mandoc.

.It

Display offsets

.Sx \&Bd

.Fl offset Ar center

and

.Fl offset Ar right

.Fl offset Ar right .

are disregarded in mandoc.

Groff does not implement centered and flush-right rendering either,

Furthermore, troff specifies a

but produces large indentations.

.Fl file Ar file

argument that is not supported in mandoc.

Lastly, since text is not right-justified in mandoc (or even groff),

.Fl ragged

and

.Fl filled

are aliases, as are

.Fl literal

and

.Fl unfilled .

.It

Historic groff has many un-callable macros.

The

Most of these (excluding some block-level macros) are now callable.

.Sq \eh

.It

.Pq horizontal position ,

The vertical bar

.Sq \ev

.Sq \(ba

.Pq vertical position ,

made historic groff

.Sq \em

.Qq go orbital

.Pq text colour ,

but has been a proper delimiter since then.

.Sq \eM

.It

.Pq text filling colour ,

.Sx \&It Fl nested

.Sq \ez

is assumed for all lists (it wasn't in historic groff): any list may be

.Pq zero-length character ,

nested and

.Sq \ew

.Fl enum

.Pq string length ,

lists will restart the sequence only for the sub-list.

.Sq \ek

.It

.Pq horizontal position marker ,

Some manuals use

.Sq \eo

.Sx \&Li

.Pq text overstrike ,

incorrectly by following it with a reserved character and expecting the

delimiter to render.

This is not supported in mandoc.

.It

In groff, the

.Sx \&Cd ,

.Sx \&Er ,

.Sx \&Ex ,

and

.Sx \&Rv

.Sq \es

macros were stipulated only to occur in certain manual sections.

.Pq text size

mandoc does not have these restrictions.

escape sequences are all discarded in mandoc.

.It

Newer groff and mandoc print

The

.Qq AT&T UNIX

.Sq \ef

prior to unknown arguments of

scaling unit is accepted by mandoc, but rendered as the default unit.

.Sx \&At ;

.It

older groff did nothing.

In quoted literals, groff allows pairwise double-quotes to produce a

standalone double-quote in formatted output.

This is not supported by mandoc.

.El

.Sh SEE ALSO

.Xr man 1 ,

.Xr mandoc 1 ,

.Xr eqn 7 ,

.Xr man 7 ,

.Xr mandoc_char 7

.Xr roff 7 ,

.Xr tbl 7

.Sh HISTORY

The

.Nm

language first appeared as a troff macro package in

.Bx 4.4 .

It was later significantly updated by Werner Lemberg and Ruslan Ermilov

in groff-1.17.

The standalone implementation that is part of the

.Xr mandoc 1

utility written by Kristaps Dzonsons appeared in

.Ox 4.6 .

.Sh AUTHORS

The

.Nm

CVSweb