-.\" $Id: mdoc.7,v 1.104 2010/05/14 15:17:23 kristaps Exp $
+.\" $Id: mdoc.7,v 1.155 2010/08/24 14:03:46 kristaps Exp $
.\"
-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
-.Dd $Mdocdate: May 14 2010 $
+.Dd $Mdocdate: August 24 2010 $
.Dt MDOC 7
.Os
.Sh NAME
language is used to format
.Bx
.Ux
-manuals. In this reference document, we describe its syntax, structure,
-and usage. Our reference implementation is mandoc; the
+manuals.
+This reference document describes its syntax, structure, and
+usage.
+The reference implementation is
+.Xr mandoc 1 ;
+the
.Sx COMPATIBILITY
section describes compatibility with other troff \-mdoc implementations.
.Pp
An
.Nm
-document follows simple rules: lines beginning with the control
+document follows simple rules: lines beginning with the control
character
.Sq \.
-are parsed for macros. Other lines are interpreted within the scope of
+are parsed for macros.
+Other lines are interpreted within the scope of
prior macros:
.Bd -literal -offset indent
\&.Sh Macro lines change control state.
.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
+character, and, in certain circumstances, the tab character.
+All manuals must have
.Ux
line terminators.
.Ss Comments
Text following a
-.Sq \e" ,
+.Sq \e\*q ,
whether in a macro or free-form text line, is ignored to the end of
-line. A macro line with only a control character and comment escape,
-.Sq \&.\e" ,
-is also ignored. Macro lines with only a control charater and optionally
-whitespace are stripped from input.
+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 optional whitespace are
+stripped from input.
.Ss Reserved Characters
Within a macro line, the following characters are reserved:
.Pp
.Pp
Use of reserved characters is described in
.Sx MACRO SYNTAX .
-For general use in macro lines, these characters must either be escaped
+For general use in macro lines, these characters can either be escaped
with a non-breaking space
.Pq Sq \e&
-or, if applicable, an appropriate escape sequence used.
+or, if applicable, an appropriate escape sequence can be used.
.Ss Special Characters
Special characters may occur in both macro and free-form lines.
Sequences begin with the escape character
.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.
.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
A numerical representation 3, 2, or 1 (bold, italic, and Roman,
respectively) may be used instead.
A text decoration is valid within
-the current font scope only: if a macro opens a font scope alongside
+the current font scope only: if a macro opens a font scope alongside
its own scope, such as
.Sx \&Bf
.Cm \&Sy ,
is specified outside of any font scope, such as in unenclosed, free-form
text, it will affect the remainder of the document.
.Pp
-Text may also be sized with the
-.Sq \es
-escape, whose syntax is one of
-.Sq \es+-n
-for one-digit numerals;
-.Sq \es(+-nn
-or
-.Sq \es+-(nn
-for two-digit numerals; and
-.Sq \es[+-N] ,
-.Sq \es+-[N] ,
-.Sq \es'+-N' ,
-or
-.Sq \es+-'N'
-for arbitrary-digit numerals:
-.Pp
-.D1 \es+1bigger\es-1
-.D1 \es[+10]much bigger\es[-10]
-.D1 \es+(10much bigger\es-(10
-.D1 \es+'100'much much bigger\es-'100'
-.Pp
-Note these forms are
+Note this form is
.Em not
recommended for
.Nm ,
which encourages semantic annotation.
.Ss Predefined Strings
Historically,
-.Xr groff 1
+troff
also defined a set of package-specific
.Dq predefined strings ,
which, like
.Sx Special Characters ,
-demark special output characters and strings by way of input codes.
+mark special output characters and strings by way of input codes.
Predefined strings are escaped with the slash-asterisk,
.Sq \e* :
single-character
.Pq vertical bar .
.Ss Whitespace
Whitespace consists of the space character.
-In free-form lines, whitespace is preserved within a line; un-escaped
+In free-form lines, whitespace is preserved within a line; unescaped
trailing spaces are stripped from input (unless in a literal context).
Blank free-form lines, which may include whitespace, are only permitted
within literal contexts.
In macro lines, whitespace delimits arguments and is discarded.
If arguments are quoted, whitespace within the quotes is retained.
.Ss Quotation
-Macro arguments may be quoted with a double-quote to group
+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
-This produces tokens
-.Sq a" ,
-.Sq b c ,
-.Sq de ,
-and
-.Sq fg" .
-Note that any quoted term, be it argument or macro, is indiscriminately
-considered literal text.
+Note that any quoted text, even if it would cause a macro invocation
+when unquoted, is considered literal text.
Thus, the following produces
-.Sq \&Em a :
+.Sq Op "Fl a" :
.Bd -literal -offset indent
-\&.Em "Em a"
+\&.Op "Fl a"
.Ed
.Pp
In free-form mode, quotes are regarded as opaque text.
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.
+or question mark followed by zero or more non-sentence closing
+delimiters (
+.Ns Sq \&) ,
+.Sq \&] ,
+.Sq \&' ,
+.Sq \&" ) .
.Pp
The proper spacing is also intelligently preserved if a sentence ends at
the boundary of a macro line.
+For example:
+.Pp
+.D1 \&Xr mandoc 1 \.
+.D1 \&Fl T \&Ns \&Cm ascii \.
.Sh MANUAL STRUCTURE
A well-formed
.Nm
document consists of a document prologue followed by one or more
sections.
.Pp
-The prologue, which consists of (in order) the
+The prologue, which consists of the
.Sx \&Dd ,
.Sx \&Dt ,
and
.Sx \&Os
-macros, is required for every document.
+macros in that order, is required for every document.
.Pp
The first section (sections are denoted by
.Sx \&Sh )
followed by
.Sx \&Nd .
.Pp
-Following that, convention dictates specifying at least the SYNOPSIS and
-DESCRIPTION sections, although this varies between manual sections.
+Following that, convention dictates specifying at least the
+.Em SYNOPSIS
+and
+.Em DESCRIPTION
+sections, although this varies between manual sections.
.Pp
The following is a well-formed skeleton
.Nm
\&.Dd $\&Mdocdate$
\&.Dt mdoc 7
\&.Os
-\&.
\&.Sh NAME
\&.Nm foo
\&.Nd a description goes here
-\&.\e\*q The next is for sections 2 & 3 only.
+\&.\e\*q The next is for sections 2, 3, & 9 only.
\&.\e\*q .Sh LIBRARY
-\&.
\&.Sh SYNOPSIS
\&.Nm foo
\&.Op Fl options
\&.Ar
-\&.
\&.Sh DESCRIPTION
The
\&.Nm
\&.\e\*q .Sh SECURITY CONSIDERATIONS
.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 short 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 name1
+\&.Nm name0 ,
+\&.Nm name1 ,
\&.Nm name2
-\&.Nd a short description
+\&.Nd a one line description
.Ed
.Pp
The
.Sx \&Nd .
.It Em LIBRARY
The name of the library containing the documented material, which is
-assumed to be a function in a section 2 or 3 manual.
+assumed to be a function in a section 2, 3, or 9 manual.
The syntax for this is as follows:
.Bd -literal -offset indent
\&.Lb libarm
.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 *"
Manuals not in these sections generally don't need a
.Em SYNOPSIS .
.Pp
-See
-.Sx \&Op ,
+Some macros are displayed differently in the
+.Em SYNOPSIS
+section, particularly
+.Sx \&Nm ,
.Sx \&Cd ,
+.Sx \&Fd ,
.Sx \&Fn ,
-.Sx \&Ft ,
+.Sx \&Fo ,
+.Sx \&In ,
+.Sx \&Vt ,
and
-.Sx \&Vt .
+.Sx \&Ft .
+All of these macros are output on their own line.
+If two such dissimilar macros are pairwise invoked (except for
+.Sx \&Ft
+before
+.Sx \&Fo
+or
+.Sx \&Fn ) ,
+they are separated by a vertical space, unless in the case of
+.Sx \&Fo ,
+.Sx \&Fn ,
+and
+.Sx \&Ft ,
+which are always separated by vertical space.
+.Pp
+When text and macros following an
+.Sx \&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
+.Sx \&Nm
+macro, up to the next
+.Sx \&Nm ,
+.Sx \&Sh ,
+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 expands upon the brief, one line description in
.Em NAME .
-It usually contains a break-down of the options (if documenting a
+It usually contains a breakdown of the options (if documenting a
command), such as:
.Bd -literal -offset indent
The arguments are as follows:
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
-.Em EXIT STATUS ,
-which is used for commands.
-It documents the return values of functions in sections 2, 3, and 9.
+This section documents the
+return values of functions in sections 2, 3, and 9.
.Pp
See
.Sx \&Rv .
.It Em ENVIRONMENT
-Documents any usages of environment variables, e.g.,
-.Xr environ 7 .
+Lists the environment variables used by the utility,
+and explains the syntax and semantics of their values.
+The
+.Xr environ 7
+manual provides examples of typical content and formatting.
.Pp
See
.Sx \&Ev .
.It Em FILES
Documents files used.
-It's helpful to document both the file and a short description of how
+It's helpful to document both the file name and a short description of how
the file is used (created, modified, etc.).
.Pp
See
.Sx \&Pa .
.It Em EXIT STATUS
-Command exit status for section 1, 6, and 8 manuals.
-This section is the dual of
-.Em RETURN VALUES ,
-which is used for functions.
+This section documents the
+command exit status for section 1, 6, and 8 utilities.
Historically, this information was described in
.Em DIAGNOSTICS ,
a practise that is now discouraged.
.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.
See
.Sx \&St .
.It Em HISTORY
-The history of any manual without a
-.Em STANDARDS
-section should be described in this section.
+A brief history of the subject, including where support first appeared.
.It Em AUTHORS
-Credits to authors, if applicable, should appear in this section.
-Authors should generally be noted by both name and an e-mail address.
+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
.Sx \&An .
.It Em CAVEATS
-Explanations of common misuses and misunderstandings should be explained
+Common misuses and misunderstandings should be explained
in this section.
.It Em BUGS
-Extant bugs should be described in this section.
+Known bugs, limitations, and work-arounds should be described
+in this section.
.It Em SECURITY CONSIDERATIONS
Documents any security precautions that operators should consider.
.El
.Sh MACRO SYNTAX
Macros are one to three three characters in length and begin with a
-control character ,
+control character,
.Sq \&. ,
at the beginning of the line.
An arbitrary amount of whitespace may sit between the control character
.Sq Fl \&Sh .
.Pp
The
-.Em Parsable
+.Em Parsed
column indicates whether the macro may be followed by further
(ostensibly callable) macros.
-If a macro is not parsable, subsequent macro invocations on the line
+If a macro is not parsed, subsequent macro invocations on the line
will be interpreted as opaque text.
.Pp
The
\&.Yc
.Ed
.Pp
-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
.It Sx \&Bd Ta \&No Ta \&No Ta closed by Sx \&Ed
.It Sx \&Bf Ta \&No Ta \&No Ta closed by Sx \&Ef
.It Sx \&Bk Ta \&No Ta \&No Ta closed by Sx \&Ek
.Pc
don't have heads; only one
.Po
-.Sx \&It Fl column
+.Sx \&It
+in
+.Sx \&Bl Fl column
.Pc
has multiple heads.
.Bd -literal -offset indent
\(lBbody...\(rB
.Ed
.Pp
-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXXXXXXXXXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
.It Sx \&It Ta \&No Ta Yes Ta closed by Sx \&It , Sx \&El
.It Sx \&Nd Ta \&No Ta \&No Ta closed by Sx \&Sh
+.It Sx \&Nm Ta \&No Ta Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss
.It Sx \&Sh Ta \&No Ta \&No Ta closed by Sx \&Sh
.It Sx \&Ss Ta \&No Ta \&No Ta closed by Sx \&Sh , Sx \&Ss
.El
+.Pp
+Note that the
+.Sx \&Nm
+macro is a
+.Sx Block full-implicit
+macro only when invoked as the first macro
+in a
+.Em SYNOPSIS
+section line, else it is
+.Sx In-line .
.Ss 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
\(lBbody...\(rB \&Yc \(lBtail...\(rB
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXXX" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.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 \&Ac Ta Yes Ta Yes Ta opened by Sx \&Ao
.It Sx \&Ao Ta Yes Ta Yes Ta closed by Sx \&Ac
.It Sx \&Bc Ta Yes Ta Yes Ta closed by Sx \&Bo
\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable
+.Bl -column "MacroX" "CallableX" "ParsedX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed
.It Sx \&Aq Ta Yes Ta Yes
.It Sx \&Bq Ta Yes Ta Yes
.It Sx \&Brq Ta Yes Ta Yes
macro is a
.Sx Block partial-implicit
only when invoked as the first macro
-in a SYNOPSIS section line, else it is
+in a
+.Em SYNOPSIS
+section line, else it is
.Sx In-line .
.Ss In-line
Closed by
.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...
\&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments
+.Bl -column "MacroX" "CallableX" "ParsedX" "Arguments" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Arguments
.It Sx \&%A Ta \&No Ta \&No Ta >0
.It Sx \&%B Ta \&No Ta \&No Ta >0
.It Sx \&%C Ta \&No Ta \&No Ta >0
.It Sx \&Cd Ta Yes Ta Yes Ta >0
.It Sx \&Cm Ta Yes Ta Yes Ta n
.It Sx \&Db Ta \&No Ta \&No Ta 1
-.It Sx \&Dd Ta \&No Ta \&No Ta >0
+.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 \&Dx Ta Yes Ta Yes Ta n
.Ss \&%A
Author name of an
.Sx \&Rs
-block. Multiple authors should each be accorded their own
+block.
+Multiple authors should each be accorded their own
.Sx \%%A
-line. Author names should be ordered with full or abbreviated
-forename(s) first, then full surname.
+line.
+Author names should be ordered with full or abbreviated forename(s)
+first, then full surname.
.Ss \&%B
Book title of an
.Sx \&Rs
-block. This macro may also be used in a non-bibliographic context when
+block.
+This macro may also be used in a non-bibliographic context when
referring to book titles.
.Ss \&%C
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
+block.
+This should follow the reduced or canonical form syntax described in
.Sx Dates .
.Ss \&%I
Publisher or issuer name of an
.Ss \&%Q
Institutional author (school, government, etc.) of an
.Sx \&Rs
-block. Multiple institutional authors should each be accorded their own
+block.
+Multiple institutional authors should each be accorded their own
.Sx \&%Q
line.
.Ss \&%R
.Ss \&%T
Article title of an
.Sx \&Rs
-block. This macro may also be used in a non-bibliographical context
-when referring to article titles.
+block.
+This macro may also be used in a non-bibliographical context when
+referring to article titles.
.Ss \&%U
URI of reference document.
.Ss \&%V
.Sx \&Rs
block.
.Ss \&Ac
-Closes an
+Close an
.Sx \&Ao
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Ad
-Address construct: usually in the context of an computational address in
-memory, not a physical (post) address.
+Memory address.
+Do not use this for postal addresses.
.Pp
Examples:
.D1 \&.Ad [0,$]
.D1 \&.Ad 0x00000000
.Ss \&An
Author name.
-This macro may alternatively accepts the following arguments, although
-these may not be specified along with a parameter:
-.Bl -tag -width 12n -offset indent
+Requires either the name of an author or one of the following arguments:
+.Pp
+.Bl -tag -width "-nosplitX" -offset indent -compact
.It Fl split
-Renders a line break before each author listing.
+Start a new output line before each subsequent invocation of
+.Sx \&An .
.It Fl nosplit
The opposite of
.Fl split .
.El
.Pp
-In the AUTHORS section, the default is not to split the first author
-listing, but all subsequent author listings, whether or not they're
-interspersed by other macros or text, are split.
-Thus, specifying
+The default is
+.Fl nosplit .
+The effect of selecting either of the
+.Fl split
+modes ends at the beginning of the
+.Em AUTHORS
+section.
+In the
+.Em AUTHORS
+section, the default is
+.Fl nosplit
+for the first author listing and
.Fl split
-will cause the first listing also to be split.
-If not in the AUTHORS section, the default is not to split.
+for all other author listings.
.Pp
Examples:
.D1 \&.An -nosplit
-.D1 \&.An J. D. Ullman .
-.Pp
-.Em Remarks :
-the effects of
-.Fl split
-or
-.Fl nosplit
-are re-set when entering the AUTHORS section, so if one specifies
-.Sx \&An Fl nosplit
-in the general document body, it must be re-specified in the AUTHORS
-section.
+.D1 \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv
.Ss \&Ao
-Begins a block enclosed by angled brackets.
+Begin a block enclosed by angle brackets.
Does not have any head arguments.
.Pp
Examples:
See also
.Sx \&Aq .
.Ss \&Ap
-Inserts an apostrophe without any surrounding white-space.
-This is generally used as a grammatic device when referring to the verb
-form of a function:
-.Bd -literal -offset indent
-\&.Fn execve Ap d
-.Ed
+Inserts an apostrophe without any surrounding whitespace.
+This is generally used as a grammatical device when referring to the verb
+form of a function.
+.Pp
+Examples:
+.D1 \&.Fn execve \&Ap d
.Ss \&Aq
-Encloses its arguments in angled brackets.
+Encloses its arguments in angle brackets.
.Pp
Examples:
.D1 \&.Fl -key= \&Ns \&Aq \&Ar val
.Ss \&Ar
Command arguments.
If an argument is not provided, the string
-.Dq file ...
+.Dq file ...\&
is used as a default.
.Pp
Examples:
.D1 \&.Ar arg1 , arg2 .
.Ss \&At
Formats an AT&T version.
-Accepts at most one parameter:
-.Bl -tag -width 12n -offset indent
+Accepts one optional argument:
+.Pp
+.Bl -tag -width "v[1-7] | 32vX" -offset indent -compact
.It Cm v[1-7] | 32v
A version of
.At .
.It Cm V[.[1-4]]?
-A system version of
-.At .
+A version of
+.At V .
.El
.Pp
-Note that these parameters do not begin with a hyphen.
+Note that these arguments do not begin with a hyphen.
.Pp
Examples:
.D1 \&.At
and
.Sx \&Ux .
.Ss \&Bc
-Closes a
+Close a
.Sx \&Bo
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Bd
-Begins a display block.
-A display is collection of macros or text which may be collectively
-offset or justified in a manner different from that
-of the enclosing context.
-By default, the block is preceded by a vertical space.
-.Pp
-Each display is associated with a type, which must be one of the
-following arguments:
-.Bl -tag -width 12n -offset indent
-.It Fl ragged
-Only left-justify the block.
-.It Fl unfilled
-Do not justify the block at all.
+Begin a display block.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bd
+.Fl Ns Ar type
+.Op Fl offset Ar width
+.Op Fl compact
+.Ed
+.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.
+By default, a display block is preceded by a vertical space.
+.Pp
+The
+.Ar type
+must be one of the following:
+.Bl -tag -width 13n -offset indent
+.It Fl centered
+Centre-justify each line.
+Using this display type is not recommended; many
+.Nm
+implementations render it poorly.
.It Fl filled
Left- and right-justify the block.
.It Fl literal
-Alias for
-.Fl unfilled .
-.It Fl centered
-Centre-justify each line.
+Do not justify the block at all.
+Preserve white space as it appears in the input.
+.It Fl ragged
+Only left-justify the block.
+.It Fl unfilled
+An alias for
+.Fl literal .
.El
.Pp
-The type must be provided first.
-Secondary arguments are as follows:
-.Bl -tag -width 12n -offset indent
+The
+.Ar type
+must be provided first.
+Additional arguments may follow:
+.Bl -tag -width 13n -offset indent
.It Fl offset Ar width
-Offset by the value of
+Indent the display by the
.Ar width ,
-which is interpreted as one of the following, specified in order:
+which may be one of the following:
.Bl -item
.It
-As one of the pre-defined strings
-.Ar indent ,
+One of the pre-defined strings
+.Cm indent ,
the width of standard indentation;
-.Ar indent-two ,
+.Cm indent-two ,
twice
-.Ar indent ;
-.Ar left ,
-which has no effect ;
-.Ar right ,
-which justifies to the right margin; and
-.Ar center ,
+.Cm indent ;
+.Cm left ,
+which has no effect;
+.Cm right ,
+which justifies to the right margin; or
+.Cm center ,
which aligns around an imagined centre axis.
.It
-As a precalculated width for a named macro.
+A macro invocation, which selects a predefined width
+associated with that macro.
The most popular is the imaginary macro
.Ar \&Ds ,
which resolves to
-.Ar 6n .
+.Sy 6n .
.It
-As a scaling unit following the syntax described in
+A width using the syntax described in
.Sx Scaling Widths .
.It
-As the calculated string length of the opaque string.
+An arbitrary string, which indents by the length of this string.
.El
.Pp
-If unset, it will revert to the value of
-.Ar 8n
-as described in
-.Sx Scaling Widths .
+When the argument is missing,
+.Fl offset
+is ignored.
.It Fl compact
-Do not assert a vertical space before the block.
-.It Fl file Ar file
-Prepend the file
-.Ar file
-before any text or macros within the block.
+Do not assert vertical space before the display.
.El
.Pp
Examples:
.Bd -literal -offset indent
-\&.Bd \-unfilled \-offset two-indent \-compact
+\&.Bd \-literal \-offset indent \-compact
Hello world.
\&.Ed
.Ed
and
.Sx \&Dl .
.Ss \&Bf
+Change the font mode for a scoped block of text.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bf
+.Oo
+.Fl emphasis | literal | symbolic |
+.Cm \&Em | \&Li | \&Sy
+.Oc
+.Ed
+.Pp
+The
+.Fl emphasis
+and
+.Cm \&Em
+argument are equivalent, as are
+.Fl symbolic
+and
+.Cm \&Sy ,
+and
+.Fl literal
+and
+.Cm \&Li .
+Without an argument, this macro does nothing.
+The font mode continues until broken by a new font mode in a nested
+scope or
+.Sx \&Ef
+is encountered.
+.Pp
+See also
+.Sx \&Li ,
+.Sx \&Ef ,
+.Sx \&Em ,
+and
+.Sx \&Sy .
.Ss \&Bk
+Keep the output generated from each macro input line together
+on one single output line.
+Line breaks in free-form text lines are unaffected.
+The syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Bk Fl words
+.Pp
+The
+.Fl words
+argument is required; additional arguments are ignored.
+.Pp
+The following example will not break within each
+.Sx \&Op
+macro line:
+.Bd -literal -offset indent
+\&.Bk \-words
+\&.Op Fl f Ar flags
+\&.Op Fl o Ar output
+\&.Ek
+.Ed
+.Pp
+Be careful in using over-long lines within a keep block!
+Doing so will clobber the right margin.
.Ss \&Bl
-Begins a list composed of one or more list entries.
-A list is associated with a type, which is a required argument.
-Other arguments are
-.Fl width ,
-defined per-type as accepting a literal or
-.Sx Scaling Widths
-value;
-.Fl offset ,
-also accepting a literal or
-.Sx Scaling Widths
-value setting the list's global offset; and
-.Fl compact ,
-suppressing the default vertical space printed before each list entry.
-A list entry is specified by the
+Begin a list.
+Lists consist of items started by the
.Sx \&It
-macro, which consists of a head and optional body (depending on the list
-type).
+macro, containing a head or a body or both.
+The list syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bl
+.Fl Ns Ar type
+.Op Fl width Ar val
+.Op Fl offset Ar val
+.Op Fl compact
+.Op HEAD ...
+.Ed
+.Pp
+The list
+.Ar type
+is mandatory and must be specified first.
+The
+.Fl width
+and
+.Fl offset
+arguments accept
+.Sx Scaling Widths
+or use the length of the given string.
+The
+.Fl offset
+is a global indentation for the whole list, affecting both item heads
+and bodies.
+For those list types supporting it, the
+.Fl width
+argument requests an additional indentation of item bodies,
+to be added to the
+.Fl offset .
+Unless the
+.Fl compact
+argument is specified, list entries are separated by vertical space.
+.Pp
A list must specify one of the following list types:
.Bl -tag -width 12n -offset indent
.It Fl bullet
-A list offset by a bullet.
-The head of list entries must be empty.
-List entry bodies are positioned after the bullet.
-The
+No item heads can be specified, but a bullet will be printed at the head
+of each item.
+Item bodies start on the same output line as the bullet
+and are indented according to the
.Fl width
-argument varies the width of list bodies' left-margins.
+argument.
.It Fl column
A columnated list.
The
.Fl width
-argument has no effect.
-The number of columns is specified as parameters to the
-.Sx \&Bl
-macro.
-These dictate the width of columns either as
+argument has no effect; instead, each argument specifies the width
+of one column, using either the
.Sx Scaling Widths
-or literal text.
-List entry bodies must be left empty.
-Column bodies have the following syntax:
-.Pp
-.D1 .It col1 <TAB> ... coln
-.D1 .It col1 Ta ... coln
-.D1 .It col1 <TAB> col2 Ta coln
-.Pp
-where columns may be separated by tabs, the literal string
-.Qq Ta ,
-or a mixture of both.
-These are equivalent except that quoted sections propogate over tabs,
-for example,
-.Pp
-.D1 .It \(dqcol1 ; <TAB> col2 ;\(dq ;
-.Pp
-will preserve the semicolon whitespace except for the last.
+syntax or the string length of the argument.
+If the first line of the body of a
+.Fl column
+list is not an
+.Sx \&It
+macro line,
+.Sx \&It
+contexts spanning one input line each are implied until an
+.Sx \&It
+macro line is encountered, at which point items start being interpreted as
+described in the
+.Sx \&It
+documentation.
.It Fl dash
-A list offset by a dash (hyphen).
-The head of list entries must be empty.
-List entry bodies are positioned past the dash.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
+Like
+.Fl bullet ,
+except that dashes are used in place of bullets.
.It Fl diag
Like
.Fl inset ,
-but with additional formatting to the head.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
+except that item heads are not parsed for macro invocations.
+.\" but with additional formatting to the head.
.It Fl enum
-An enumerated list offset by the enumeration from 1.
-The head of list entries must be empty.
-List entry bodies are positioned after the enumeration.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
+A numbered list.
+Formatted like
+.Fl bullet ,
+except that cardinal numbers are used in place of bullets,
+starting at 1.
.It Fl hang
Like
.Fl tag ,
-but instead of list bodies positioned after the head, they trail the
-head text.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
+except that the first lines of item bodies are not indented, but follow
+the item heads like in
+.Fl inset
+lists.
.It Fl hyphen
Synonym for
.Fl dash .
.It Fl inset
-List bodies follow the list head.
-The
+Item bodies follow items heads on the same line, using normal inter-word
+spacing.
+Bodies are not indented, and the
.Fl width
argument is ignored.
.It Fl item
-This produces blocks of text.
-The head of list entries must be empty.
-The
+No item heads can be specified, and none are printed.
+Bodies are not indented, and the
.Fl width
argument is ignored.
.It Fl ohang
-List bodies are positioned on the line following the head.
+Item bodies start on the line following item heads and are not indented.
The
.Fl width
argument is ignored.
.It Fl tag
-A list offset by list entry heads. List entry bodies are positioned
-after the head as specified by the
+Item bodies are indented according to the
.Fl width
argument.
+When an item head fits inside the indentation, the item body follows
+this head on the same output line.
+Otherwise, the body starts on the output line following the head.
.El
+.Pp
+See also
+.Sx \&El
+and
+.Sx \&It .
.Ss \&Bo
-Begins a block enclosed by square brackets.
+Begin a block enclosed by square brackets.
Does not have any head arguments.
.Pp
Examples:
-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact
\&.Bo 1 ,
\&.Dv BUFSIZ \&Bc
.Ed
See also
.Sx \&Bo .
.Ss \&Brc
-Closes a
+Close a
.Sx \&Bro
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Bro
-Begins a block enclosed by curly braces.
+Begin a block enclosed by curly braces.
Does not have any head arguments.
.Pp
Examples:
-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact
\&.Bro 1 , ... ,
\&.Va n \&Brc
.Ed
.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.
and
.Sx \&Ux .
.Ss \&Cd
-Configuration declaration.
+Kernel configuration declaration.
This denotes strings accepted by
.Xr config 8 .
.Pp
.Pp
.Em Remarks :
this macro is commonly abused by using quoted literals to retain
-white-space and align consecutive
+whitespace and align consecutive
.Sx \&Cd
declarations.
This practise is discouraged.
and
.Sx \&Dl .
.Ss \&Db
+Switch debugging mode.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Db Cm on | off
+.Pp
+This macro is ignored by
+.Xr mandoc 1 .
.Ss \&Dc
-Closes a
+Close a
.Sx \&Do
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Dd
Document date.
This is the mandatory first macro of any
.Nm
manual.
-Its calling syntax is as follows:
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Dd Cm date
+.D1 Pf \. Sx \&Dd Op Ar date
.Pp
The
-.Cm date
-field may be either
+.Ar date
+may be either
.Ar $\&Mdocdate$ ,
which signifies the current manual revision date dictated by
.Xr cvs 1 ,
or instead a valid canonical date as specified by
.Sx Dates .
-If a date does not conform, the current date is used instead.
+If a date does not conform or is empty, the current date is used.
.Pp
Examples:
.D1 \&.Dd $\&Mdocdate$
It is followed by a newline.
.Pp
Examples:
-.D1 \&.Dl % mandoc mdoc.7 | less
+.D1 \&.Dl % mandoc mdoc.7 \e(ba less
.Pp
See also
.Sx \&Bd
and
.Sx \&D1 .
.Ss \&Do
-Begins a block enclosed by double quotes. Does not have any head
-arguments.
+Begin a block enclosed by double quotes.
+Does not have any head arguments.
.Pp
Examples:
-.D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot
+.Bd -literal -offset indent -compact
+\&.Do
+April is the cruellest month
+\&.Dc
+\e(em T.S. Eliot
+.Ed
.Pp
See also
.Sx \&Dq .
.Ss \&Dq
-Encloses its arguments in double quotes.
+Encloses its arguments in
+.Dq typographic
+double-quotes.
.Pp
Examples:
.Bd -literal -offset indent -compact
.Ed
.Pp
See also
+.Sx \&Qq ,
+.Sx \&Sq ,
+and
.Sx \&Do .
.Ss \&Dt
Document title.
This is the mandatory second macro of any
.Nm
file.
-Its calling syntax is as follows:
-.Pp
-.D1 \. Ns Sx \&Dt Cm title section Op Cm volume | arch
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Dt
+.Oo
+.Ar title
+.Oo
+.Ar section
+.Op Ar volume | arch
+.Oc
+.Oc
+.Ed
.Pp
Its arguments are as follows:
.Bl -tag -width Ds -offset Ds
-.It Cm title
-The document's title (name).
-This should be capitalised and is required.
-.It Cm section
+.It Ar title
+The document's title (name), defaulting to
+.Dq UNKNOWN
+if unspecified.
+It should be capitalised.
+.It Ar section
The manual section.
This may be one of
.Ar 1
or
.Ar paper
.Pq paper .
-It is also required and should correspond to the manual's filename
-suffix.
-.It Cm volume
+It should correspond to the manual's filename suffix and defaults to
+.Dq 1
+if unspecified.
+.It Ar volume
This overrides the volume inferred from
.Ar section .
This field is optional, and if specified, must be one of
or
.Ar CON
.Pq contributed manuals .
-.It Cm arch
+.It Ar arch
This specifies a specific relevant architecture.
If
-.Cm volume
+.Ar volume
is not provided, it may be used in its place, else it may be used
subsequent that.
It, too, is optional.
.D1 \&.Dt FOO 1
.D1 \&.Dt FOO 4 KM
.D1 \&.Dt FOO 9 i386
-.D1 \&.Dt FOO 9 KM i386
.Pp
See also
.Sx \&Dd
and
.Sx \&Ux .
.Ss \&Ec
+Close a scope started by
+.Sx \&Eo .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ec Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure tail, for example, specifying \e(rq
+will emulate
+.Sx \&Dc .
.Ss \&Ed
+End a display context started by
+.Sx \&Bd .
.Ss \&Ef
+End a font mode context started by
+.Sx \&Bf .
.Ss \&Ek
+End a keep context started by
+.Sx \&Bk .
.Ss \&El
+End a list context started by
+.Sx \&Bl .
+.Pp
+See also
+.Sx \&Bl
+and
+.Sx \&It .
.Ss \&Em
Denotes text that should be emphasised.
Note that this is a presentation term and should not be used for
Examples:
.D1 \&.Em Warnings!
.D1 \&.Em Remarks :
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Sy ,
+and
+.Sx \&Li .
.Ss \&En
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
.Ss \&Eo
+An arbitrary enclosure.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Eo Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure head, for example, specifying \e(lq
+will emulate
+.Sx \&Do .
.Ss \&Er
Display error constants.
.Pp
See also
.Sx \&Dv .
.Ss \&Es
+This macro is obsolete and not implemented.
.Ss \&Ev
Environmental variables such as those specified in
.Xr environ 7 .
.D1 \&.Ev DISPLAY
.D1 \&.Ev PATH
.Ss \&Ex
-Inserts text regarding a utility's exit values.
-This macro must have first the
-.Fl std
-argument specified, then an optional
-.Ar utility .
-If
+Insert a standard sentence regarding exit values.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ex Fl std Op Ar utility
+.Pp
+When
.Ar utility
-is not provided, the document's name as stipulated in
+is not specified, the document's name set by
.Sx \&Nm
-is provided.
+is used.
+.Pp
+See also
+.Sx \&Rv .
.Ss \&Fa
+Function argument.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Fa
+.Op Cm argtype
+.Cm argname
+.Ed
+.Pp
+This may be invoked for names with or without the corresponding type.
+It is also used to specify the field name of a structure.
+Most often, the
+.Sx \&Fa
+macro is used in the
+.Em SYNOPSIS
+within
+.Sx \&Fo
+section when documenting multi-line function prototypes.
+If invoked with multiple arguments, the arguments are separated by a
+comma.
+Furthermore, if the following macro is another
+.Sx \&Fa ,
+the last argument will also have a trailing comma.
+.Pp
+Examples:
+.D1 \&.Fa \(dqconst char *p\(dq
+.D1 \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
+.D1 \&.Fa foo
+.Pp
+See also
+.Sx \&Fo .
.Ss \&Fc
+End a function context started by
+.Sx \&Fo .
.Ss \&Fd
+Historically used to document include files.
+This usage has been deprecated in favour of
+.Sx \&In .
+Do not use this macro.
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+and
+.Sx \&In .
.Ss \&Fl
Command-line flag.
Used when listing arguments to command-line utilities.
See also
.Sx \&Cm .
.Ss \&Fn
+A function name.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Ns Sx \&Fn
+.Op Cm functype
+.Cm funcname
+.Op Oo Cm argtype Oc Cm argname
+.Ed
+.Pp
+Function arguments are surrounded in parenthesis and
+are delimited by commas.
+If no arguments are specified, blank parenthesis are output.
+.Pp
+Examples:
+.D1 \&.Fn "int funcname" "int arg0" "int arg1"
+.D1 \&.Fn funcname "int arg0"
+.D1 \&.Fn funcname arg0
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+and
+.Sx \&Ft .
.Ss \&Fo
-.Ss \&Fr
+Begin a function block.
+This is a multi-line version of
+.Sx \&Fn .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Fo Cm funcname
+.Pp
+Invocations usually occur in the following context:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Ft Cm functype
+.br
+.Pf \. Sx \&Fo Cm funcname
+.br
+.Pf \. Sx \&Fa Oo Cm argtype Oc Cm argname
+.br
+\.\.\.
+.br
+.Pf \. Sx \&Fc
+.Ed
+.Pp
+A
+.Sx \&Fo
+scope is closed by
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fa ,
+.Sx \&Fc ,
+and
+.Sx \&Ft .
.Ss \&Ft
+A function type.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ft Cm functype
+.Pp
+Examples:
+.D1 \&.Ft int
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fn ,
+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:
and
.Sx \&Ux .
.Ss \&Hf
+This macro is obsolete and not implemented.
.Ss \&Ic
+Designate an internal or interactive command.
+This is similar to
+.Sx \&Cm
+but used for instructions rather than values.
+.Pp
+Examples:
+.D1 \&.Ic hash
+.D1 \&.Ic alias
+.Pp
+Note that using
+.Sx \&Bd Fl literal
+or
+.Sx \&D1
+is preferred for displaying code; the
+.Sx \&Ic
+macro is used when referring to specific instructions.
.Ss \&In
+An
+.Dq include
+file.
+In the
+.Em SYNOPSIS
+section (only if invoked as the line macro), the first argument is
+preceded by
+.Dq #include ,
+the arguments is enclosed in angle brackets.
+.Pp
+Examples:
+.D1 \&.In sys/types
+.Pp
+See also
+.Sx MANUAL STRUCTURE .
.Ss \&It
+A list item.
+The syntax of this macro depends on the list type.
+.Pp
+Lists
+of type
+.Fl hang ,
+.Fl ohang ,
+.Fl inset ,
+and
+.Fl diag
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Cm args
+.Pp
+Lists of type
+.Fl bullet ,
+.Fl dash ,
+.Fl enum ,
+.Fl hyphen
+and
+.Fl item
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It
+.Pp
+with subsequent lines interpreted within the scope of the
+.Sx \&It
+until either a closing
+.Sx \&El
+or another
+.Sx \&It .
+.Pp
+The
+.Fl tag
+list has the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Op Cm args
+.Pp
+Subsequent lines are interpreted as with
+.Fl bullet
+and family.
+The line arguments correspond to the list's left-hand side; body
+arguments correspond to the list's contents.
+.Pp
+The
+.Fl column
+list is the most complicated.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&It Op Cm args
+.Pp
+The
+.Cm args
+are phrases, a mix of macros and text corresponding to a line column,
+delimited by tabs or the special
+.Sq \&Ta
+pseudo-macro.
+Lines subsequent the
+.Sx \&It
+are interpreted within the scope of the last phrase.
+Calling the pseudo-macro
+.Sq \&Ta
+will open a new phrase scope (this must occur on a macro line to be
+interpreted as a macro).
+Note that the tab phrase delimiter may only be used within the
+.Sx \&It
+line itself.
+Subsequent this, only the
+.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 \&;
+.Pp
+will preserve the semicolon whitespace except for the last.
+.Pp
+See also
+.Sx \&Bl .
.Ss \&Lb
+Specify a library.
+The syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Lb Cm library
+.Pp
+The
+.Cm library
+parameter may be a system library, such as
+.Cm libz
+or
+.Cm 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
+.Em SYNOPSIS
+section as described in
+.Sx MANUAL STRUCTURE .
+.Pp
+Examples:
+.D1 \&.Lb libz
+.D1 \&.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
+stylistically decorating technical terms.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Sy ,
+and
+.Sx \&Em .
.Ss \&Lk
Format a hyperlink.
-The calling syntax is as follows:
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Lk Cm uri Op Cm name
+.D1 Pf \. Sx \&Lk Cm uri Op Cm name
.Pp
Examples:
-.D1 \&.Lk http://bsd.lv "The BSD.lv Project"
+.D1 \&.Lk http://bsd.lv \*qThe BSD.lv Project\*q
.D1 \&.Lk http://bsd.lv
.Pp
See also
.Sx \&Mt .
.Ss \&Lp
+Synonym for
+.Sx \&Pp .
.Ss \&Ms
+Display a mathematical symbol.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ms Cm symbol
+.Pp
+Examples:
+.D1 \&.Ms sigma
+.D1 \&.Ms aleph
.Ss \&Mt
+Format a
+.Dq mailto:
+hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Mt Cm address
+.Pp
+Examples:
+.D1 \&.Mt discuss@manpages.bsd.lv
.Ss \&Nd
+A one line description of the manual's content.
+This may only be invoked in the
+.Em SYNOPSIS
+section subsequent the
+.Sx \&Nm
+macro.
+.Pp
+Examples:
+.D1 \&.Sx \&Nd mdoc language reference
+.D1 \&.Sx \&Nd format and display UNIX manuals
+.Pp
+The
+.Sx \&Nd
+macro technically accepts child macros and terminates with a subsequent
+.Sx \&Sh
+invocation.
+Do not assume this behaviour: some
+.Xr whatis 1
+database generators are not smart enough to parse more than the line
+arguments and will display macros verbatim.
+.Pp
+See also
+.Sx \&Nm .
.Ss \&Nm
+The name of the manual page, or \(em in particular in section 1, 6,
+and 8 pages \(em of an additional command or feature documented in
+the manual page.
+When first invoked, the
+.Sx \&Nm
+macro expects a single argument, the name of the manual page.
+Usually, the first invocation happens in the
+.Em 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
+.Sx \&Nm
+macro uses
+.Sx Block full-implicit
+semantics when invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section; otherwise, it uses ordinary
+.Sx In-line
+semantics.
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Sh SYNOPSIS
+\&.Nm cat
+\&.Op Fl benstuv
+\&.Op Ar
+.Ed
+.Pp
+In the
+.Em SYNOPSIS
+of section 2, 3 and 9 manual pages, use the
+.Sx \&Fn
+macro rather than
+.Sx \&Nm
+to mark up the name of the manual page.
.Ss \&No
+A
+.Dq noop
+macro used to terminate prior macro contexts.
+.Pp
+Examples:
+.D1 \&.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
+Examples:
+.D1 \&.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:
and
.Sx \&Ux .
.Ss \&Oc
+Close multi-line
+.Sx \&Oo
+context.
.Ss \&Oo
+Multi-line version of
+.Sx \&Op .
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.Oo
+\&.Op Fl flag Ns Ar value
+\&.Oc
+.Ed
.Ss \&Op
+Command-line option.
+Used when listing options to command-line utilities.
+Prints the argument(s) in brackets.
+.Pp
+Examples:
+.D1 \&.Op \&Fl a \&Ar b
+.D1 \&.Op \&Ar a | b
+.Pp
+See also
+.Sx \&Oo .
.Ss \&Os
Document operating system version.
This is the mandatory third macro of
any
.Nm
-file. Its calling syntax is as follows:
+file.
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Os Op Cm system
+.D1 Pf \. Sx \&Os Op Cm system Op Cm version
.Pp
The optional
.Cm system
.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:
and
.Sx \&Ux .
.Ss \&Pa
+A file-system path.
+.Pp
+Examples:
+.D1 \&.Pa /usr/bin/mandoc
+.D1 \&.Pa /usr/share/man/man7/mdoc.7
+.Pp
+See also
+.Sx \&Lk .
.Ss \&Pc
+Close parenthesised context opened by
+.Sx \&Po .
.Ss \&Pf
+Removes the space
+.Pq Dq prefix
+between its arguments.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. \&Pf Cm prefix suffix
+.Pp
+The
+.Cm suffix
+argument may be a macro.
+.Pp
+Examples:
+.D1 \&.Pf \e. \&Sx \&Pf \&Cm prefix suffix
.Ss \&Po
+Multi-line version of
+.Sx \&Pq .
.Ss \&Pp
+Break a paragraph.
+This will assert vertical space between prior and subsequent macros
+and/or text.
.Ss \&Pq
+Parenthesised enclosure.
+.Pp
+See also
+.Sx \&Po .
.Ss \&Qc
+Close quoted context opened by
+.Sx \&Qo .
.Ss \&Ql
+Format a single-quoted literal.
+See also
+.Sx \&Qq
+and
+.Sx \&Sq .
.Ss \&Qo
+Multi-line version of
+.Sx \&Qq .
.Ss \&Qq
+Encloses its arguments in
+.Dq typewriter
+double-quotes.
+Consider using
+.Sx \&Dq .
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Sq ,
+and
+.Sx \&Qo .
.Ss \&Re
-Closes a
+Close an
.Sx \&Rs
block.
Does not have any tail arguments.
.Ss \&Rs
-Begins a bibliographic
+Begin a bibliographic
.Pq Dq reference
block.
Does not have any head arguments.
.Sx \&%Q ,
.Sx \&%R ,
.Sx \&%T ,
+.Sx \&%U ,
and
.Sx \&%V
child macros (at least one must be specified).
before the rendered output, else the block continues on the current
line.
.Ss \&Rv
+Inserts text regarding a function call's return value.
+This macro must consist of the
+.Fl std
+argument followed by an optional
+.Ar function .
+If
+.Ar function
+is not provided, the document's name as stipulated by the first
+.Sx \&Nm
+is provided.
+.Pp
+See also
+.Sx \&Ex .
.Ss \&Sc
+Close single-quoted context opened by
+.Sx \&So .
.Ss \&Sh
+Begin a new section.
+For a list of conventional manual sections, see
+.Sx MANUAL STRUCTURE .
+These sections should be used unless it's absolutely necessary that
+custom sections be used.
+.Pp
+Section names should be unique so that they may be keyed by
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Ss ,
+and
+.Sx \&Sx .
.Ss \&Sm
+Switches the spacing mode for output generated from macros.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Sm Cm on | off
+.Pp
+By default, spacing is
+.Cm on .
+When switched
+.Cm off ,
+no white space is inserted between macro arguments and between the
+output generated from adjacent macros, but free-form text lines
+still get normal spacing between words and sentences.
.Ss \&So
+Multi-line version of
+.Sx \&Sq .
.Ss \&Sq
+Encloses its arguments in
+.Dq typewriter
+single-quotes.
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Qq ,
+and
+.Sx \&So .
.Ss \&Ss
+Begin a new sub-section.
+Unlike with
+.Sx \&Sh ,
+there's no convention for sub-sections.
+Conventional sections, as described in
+.Sx MANUAL STRUCTURE ,
+rarely have sub-sections.
+.Pp
+Sub-section names should be unique so that they may be keyed by
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Sh ,
+and
+.Sx \&Sx .
.Ss \&St
+Replace an abbreviation for a standard with the full form.
+The following standards are recognised:
+.Pp
+.Bl -tag -width "-p1003.1g-2000X" -compact
+.It \-p1003.1-88
+.St -p1003.1-88
+.It \-p1003.1-90
+.St -p1003.1-90
+.It \-p1003.1-96
+.St -p1003.1-96
+.It \-p1003.1-2001
+.St -p1003.1-2001
+.It \-p1003.1-2004
+.St -p1003.1-2004
+.It \-p1003.1-2008
+.St -p1003.1-2008
+.It \-p1003.1
+.St -p1003.1
+.It \-p1003.1b
+.St -p1003.1b
+.It \-p1003.1b-93
+.St -p1003.1b-93
+.It \-p1003.1c-95
+.St -p1003.1c-95
+.It \-p1003.1g-2000
+.St -p1003.1g-2000
+.It \-p1003.1i-95
+.St -p1003.1i-95
+.It \-p1003.2-92
+.St -p1003.2-92
+.It \-p1003.2a-92
+.St -p1003.2a-92
+.It \-p1387.2-95
+.St -p1387.2-95
+.It \-p1003.2
+.St -p1003.2
+.It \-p1387.2
+.St -p1387.2
+.It \-isoC
+.St -isoC
+.It \-isoC-90
+.St -isoC-90
+.It \-isoC-amd1
+.St -isoC-amd1
+.It \-isoC-tcor1
+.St -isoC-tcor1
+.It \-isoC-tcor2
+.St -isoC-tcor2
+.It \-isoC-99
+.St -isoC-99
+.It \-iso9945-1-90
+.St -iso9945-1-90
+.It \-iso9945-1-96
+.St -iso9945-1-96
+.It \-iso9945-2-93
+.St -iso9945-2-93
+.It \-ansiC
+.St -ansiC
+.It \-ansiC-89
+.St -ansiC-89
+.It \-ansiC-99
+.St -ansiC-99
+.It \-ieee754
+.St -ieee754
+.It \-iso8802-3
+.St -iso8802-3
+.It \-ieee1275-94
+.St -ieee1275-94
+.It \-xpg3
+.St -xpg3
+.It \-xpg4
+.St -xpg4
+.It \-xpg4.2
+.St -xpg4.2
+.St -xpg4.3
+.It \-xbd5
+.St -xbd5
+.It \-xcu5
+.St -xcu5
+.It \-xsh5
+.St -xsh5
+.It \-xns5
+.St -xns5
+.It \-xns5.2
+.St -xns5.2
+.It \-xns5.2d2.0
+.St -xns5.2d2.0
+.It \-xcurses4.2
+.St -xcurses4.2
+.It \-susv2
+.St -susv2
+.It \-susv3
+.St -susv3
+.It \-svid4
+.St -svid4
+.El
.Ss \&Sx
+Reference a section or sub-section.
+The referenced section or sub-section name must be identical to the
+enclosed argument, including whitespace.
+.Pp
+Examples:
+.D1 \&.Sx MANUAL STRUCTURE
.Ss \&Sy
+Format enclosed arguments in symbolic
+.Pq Dq boldface .
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Li ,
+and
+.Sx \&Em .
.Ss \&Tn
+Format a tradename.
+.Pp
+Examples:
+.D1 \&.Tn IBM
.Ss \&Ud
+Prints out
+.Dq currently under development .
.Ss \&Ux
Format the UNIX name.
Accepts no argument.
and
.Sx \&Ox .
.Ss \&Va
+A variable name.
+.Pp
+Examples:
+.D1 \&.Va foo
+.D1 \&.Va const char *bar ;
.Ss \&Vt
A variable type.
-This is also used for indicating global variables in the SYNOPSIS
+This is also used for indicating global variables in the
+.Em SYNOPSIS
section, in which case a variable name is also specified.
Note that it accepts
.Sx Block partial-implicit
-syntax when invoked as the first macro in the SYNOPSIS section, else it
-accepts ordinary
+syntax when invoked as the first macro in the
+.Em SYNOPSIS
+section, else it accepts ordinary
.Sx In-line
syntax.
.Pp
.Pp
Examples:
.D1 \&.Vt unsigned char
-.D1 \&.Vt extern const char * const sys_signame[] ;
+.D1 \&.Vt extern const char * const sys_signame[] \&;
.Pp
See also
-.Sx \&Ft
+.Sx MANUAL STRUCTURE
and
.Sx \&Va .
.Ss \&Xc
.Ss \&Xr
Link to another manual
.Pq Qq cross-reference .
-Its calling syntax is
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Xr Cm name section
+.D1 Pf \. Sx \&Xr Cm name section
.Pp
The
.Cm name
.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
-.D1 \&.Xr mandoc 1 ;
+.D1 \&.Xr mandoc 1 \&;
.D1 \&.Xr mandoc 1 \&Ns s behaviour
.Ss \&br
+Emits a line-break.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+.Pp
+Consider using
+.Sx \&Pp
+in the event of natural paragraph breaks.
.Ss \&sp
+Emits vertical space.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&sp Op Cm height
+.Pp
+The
+.Cm height
+argument must be formatted as described in
+.Sx Scaling Widths .
+If unspecified,
+.Sx \&sp
+asserts a single vertical space.
.Sh COMPATIBILITY
This section documents compatibility between mandoc and other other
troff implementations, at this time limited to GNU troff
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
-The comment syntax
-.Sq \e."
-is no longer accepted.
+.Sx \&At
+with unknown arguments produces no output at all.
+\*[hist]
+Newer groff and mandoc print
+.Qq AT&T UNIX
+and the arguments.
.It
-In groff, the
-.Sx \&Pa
-macro does not format its arguments when used in the FILES section under
-certain list types.
-mandoc does.
+.Sx \&Bd Fl column
+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
-Historic groff does not print a dash for empty
-.Sx \&Fl
-arguments.
-mandoc and newer groff implementations do.
+.Sx \&Bd Fl ragged compact
+does not start a new line.
+\*[hist]
.It
-groff behaves irregularly when specifying
-.Sq \ef
-.Sx Text Decoration
-within line-macro scopes.
-mandoc follows a consistent system.
+.Sx \&Dd
+without an argument prints
+.Dq Epoch .
+In mandoc, it resolves to the current date.
.It
-In mandoc, negative scaling units are truncated to zero; groff would
-move to prior lines.
-Furthermore, the
-.Sq f
-scaling unit, while accepted, is rendered as the default unit.
+.Sx \&Fl
+does not print a dash for an empty argument.
+\*[hist]
.It
-In quoted literals, groff allowed pair-wise double-quotes to produce a
-standalone double-quote in formatted output.
-This idiosyncratic behaviour is not applicable in mandoc.
+.Sx \&Fn
+does not start a new line unless invoked as the line macro in the
+.Em SYNOPSIS
+section.
+\*[hist]
.It
-Display types
-.Sx \&Bd
-.Fl center
-and
-.Fl right
-are aliases for
-.Fl left
-in manodc. Furthermore, the
-.Fl file Ar file
-argument is ignored.
-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 .
+.Sx \&Fo
+with
+.Pf non- Sx \&Fa
+children causes inconsistent spacing between arguments.
+In mandoc, a single space is always inserted between arguments.
.It
-Historic groff has many un-callable macros.
-Most of these (excluding some block-level macros) are now callable.
+.Sx \&Ft
+in the
+.Em SYNOPSIS
+causes inconsistent vertical spacing, depending on whether a prior
+.Sx \&Fn
+has been invoked.
+See
+.Sx \&Ft
+and
+.Sx \&Fn
+for the normalised behaviour in mandoc.
.It
-The vertical bar
-.Sq \(ba
-made historic groff
-.Qq go orbital
-but has been a proper delimiter since then.
+.Sx \&In
+ignores additional arguments and is not treated specially in the
+.Em SYNOPSIS .
+\*[hist]
.It
-.Sx \&It Fl nested
-is assumed for all lists (it wasn't in historic groff): any list may be
-nested and
+.Sx \&It
+sometimes requires a
+.Fl nested
+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
-Some manuals use
.Sx \&Li
-incorrectly by following it with a reserved character and expecting the
-delimiter to render.
-This is not supported in mandoc.
+followed by a reserved character is incorrectly used in some manuals
+instead of properly quoting that character, which sometimes works with
+historic groff.
.It
-In groff, the
-.Sx \&Fo
-macro only produces the first parameter.
-This is not the case in mandoc.
+.Sx \&Lk
+only accepts a single link-name argument; the remainder is misformatted.
.It
-In groff, the
-.Sx \&Cd ,
-.Sx \&Er ,
+.Sx \&Pa
+does not format its arguments when used in the FILES section under
+certain list types.
+.It
+.Sx \&Ta
+can only be called by other macros, but not at the beginning of a line.
+.It
+.Sx \&%C
+is not implemented.
+.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
+escapes behave irregularly when specified within line-macro scopes.
+.It
+Negative scaling units return to prior lines.
+Instead, mandoc truncates them to zero.
+.El
+.Pp
+The following features are unimplemented in mandoc:
+.Pp
+.Bl -dash -compact
+.It
+.Sx \&Bd
+.Fl file Ar file .
+.It
+.Sx \&Bd
+.Fl offset Ar center
+and
+.Fl offset Ar right .
+Groff does not implement centered and flush-right rendering either,
+but produces large indentations.
+.It
+The
+.Sq \eh
+.Pq horizontal position ,
+.Sq \ev
+.Pq vertical position ,
+.Sq \em
+.Pq text colour ,
+.Sq \eM
+.Pq text filling colour ,
+.Sq \ez
+.Pq zero-length character ,
+.Sq \ew
+.Pq string length ,
+.Sq \ek
+.Pq horizontal position marker ,
and
-.Sx \&Ex
-macros were stipulated only to occur in certain manual sections.
-mandoc does not have these restrictions.
+.Sq \es
+.Pq text size
+escape sequences are all discarded in mandoc.
+.It
+The
+.Sq \ef
+scaling unit is accepted by mandoc, but rendered as the default unit.
+.It
+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 mandoc 1 ,
.Xr mandoc_char 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
reference was written by
.An Kristaps Dzonsons Aq kristaps@bsd.lv .
-.\"
-.\" XXX: this really isn't the place for these caveats.
-.\" .
-.\" .
-.\" .Sh CAVEATS
-.\" There are many ambiguous parts of mdoc.
-.\" .
-.\" .Pp
-.\" .Bl -dash -compact
-.\" .It
-.\" .Sq \&Fa
-.\" should be
-.\" .Sq \&Va
-.\" as function arguments are variables.
-.\" .It
-.\" .Sq \&Ft
-.\" should be
-.\" .Sq \&Vt
-.\" as function return types are still types. Furthermore, the
-.\" .Sq \&Ft
-.\" should be removed and
-.\" .Sq \&Fo ,
-.\" which ostensibly follows it, should follow the same convention as
-.\" .Sq \&Va .
-.\" .It
-.\" .Sq \&Va
-.\" should formalise that only one or two arguments are acceptable: a
-.\" variable name and optional, preceding type.
-.\" .It
-.\" .Sq \&Fd
-.\" is ambiguous. It's commonly used to indicate an include file in the
-.\" synopsis section.
-.\" .Sq \&In
-.\" should be used, instead.
-.\" .It
-.\" Only the
-.\" .Sq \-literal
-.\" argument to
-.\" .Sq \&Bd
-.\" makes sense. The remaining ones should be removed.
-.\" .It
-.\" The
-.\" .Sq \&Xo
-.\" and
-.\" .Sq \&Xc
-.\" macros should be deprecated.
-.\" .It
-.\" The
-.\" .Sq \&Dt
-.\" macro lacks clarity. It should be absolutely clear which title will
-.\" render when formatting the manual page.
-.\" .It
-.\" A
-.\" .Sq \&Lx
-.\" should be provided for Linux (\(`a la
-.\" .Sq \&Ox ,
-.\" .Sq \&Nx
-.\" etc.).
-.\" .It
-.\" There's no way to refer to references in
-.\" .Sq \&Rs/Re
-.\" blocks.
-.\" .It
-.\" The \-split and \-nosplit dictates via
-.\" .Sq \&An
-.\" are re-set when entering and leaving the AUTHORS section.
-.\" .El
-.\" .
git.ckatri.com / mandoc.git / blobdiff