-.\" $Id: mdoc.7,v 1.197 2011/08/10 14:07:23 kristaps Exp $
+.\" $Id: mdoc.7,v 1.202 2011/08/18 08:58:44 kristaps Exp $
.\"
.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
.\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
-.Dd $Mdocdate: August 10 2011 $
+.Dd $Mdocdate: August 18 2011 $
.Dt MDOC 7
.Os
.Sh NAME
manuals.
This reference document describes its syntax, structure, and
usage.
-The reference implementation is
+The reference implementation for
+.Nm
+formatting is
.Xr mandoc 1 ;
the
.Sx COMPATIBILITY
-section describes compatibility with other troff \-mdoc implementations.
+section describes compatibility with other implementations.
.Pp
An
.Nm
character
.Sq \&.
are parsed for macros.
-Text lines, those not beginning with the control character, are
+Lines not beginning with the control character are
interpreted within the scope of prior macros:
.Bd -literal -offset indent
\&.Sh Macro lines change control state.
.Nm
documents may contain only graphable 7-bit ASCII characters, the space
character, and, in certain circumstances, the tab character.
-.Pp
-If the first character of a text line is a space, that line is printed
-with a leading newline.
+The back-space character
+.Sq \e
+indicates the start of an escape sequence for
+.Sx Comments ,
+.Sx Predefined Strings ,
+and
+.Sx Special Characters .
.Ss Comments
-Text following a
+Text following an escaped double-quote
.Sq \e\*q ,
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 ,
+A macro line beginning with a control character and comment escape
+.Sq \&.\e\*q
is also ignored.
-Macro lines with only a control character and optional whitespace are
+Furthermore,
+macro lines with only a control character and optional trailing
+whitespace are
stripped from input.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.\e\*q This is a comment line.
+\&.\e\*q The next line is ignored:
+\&.
+\&.Em Emphasis \e\*q This is also a comment.
+.Ed
.Ss Special Characters
-Special characters may occur in both macro and text lines.
+Special characters are used to encode special glyphs and are rendered
+differently across output media.
+They may occur in both macro and text lines.
Sequences begin with the escape character
.Sq \e
followed by either an open-parenthesis
for n-character sequences (terminated at a close-bracket
.Sq \&] ) ;
or a single one character sequence.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \e(em
+em dash
+.It \ee
+backslash
+.El
+.Pp
See
.Xr mandoc_char 7
for a complete list.
-Examples include
-.Sq \e(em
-.Pq em-dash
-and
-.Sq \ee
-.Pq back-slash .
.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
-(revert to previous mode):
-.Pp
-.Dl \efBbold\efR \efIitalic\efP
-.Pp
-A numerical representation 3, 2, or 1 (bold, italic, and Roman,
+escape followed by an indicator: B (bold), I (italic), R (regular), or P
+(revert to previous mode).
+A numerical representation 3, 2, or 1 (bold, italic, and regular,
respectively) may be used instead.
If a macro opens a font scope after calling
.Sq \ef ,
.Sx \&Bf
scope.
.Pp
-Note this form is
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \efBbold\efR
+write in bold, then switch to regular
+.It \efIitalic\efP
+write in italic, then return to previous
+.El
+.Pp
+Text decoration is
.Em not
recommended for
.Nm ,
which encourages semantic annotation.
.Ss Predefined Strings
-Historically,
-troff
-also defined a set of package-specific
-.Dq predefined strings ,
-which, like
+Predefined strings, like
.Sx Special Characters ,
-mark special output characters and strings by way of input codes.
+mark special output glyphs.
Predefined strings are escaped with the slash-asterisk,
.Sq \e* :
single-character
.Sq \e*(XX ,
and N-character
.Sq \e*[N] .
-See
-.Xr mandoc_char 7
-for a complete list.
-Examples include
-.Sq \e*(Am
-.Pq ampersand
-and
-.Sq \e*(Ba
-.Pq vertical bar .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \e*(Am
+ampersand
+.It \e*(Ba
+vertical bar
+.El
+.Pp
+These strings are set using
+.Xr roff 7 ,
+although
+.Nm
+consists of several pre-set escapes listed in
+.Xr mandoc_char 7 .
.Ss Whitespace
Whitespace consists of the space character.
-In text lines, whitespace is preserved within a line; unescaped
-trailing spaces are stripped from input (unless in a literal context).
-Blank text lines, which may include whitespace, are only permitted
-within literal contexts.
+In text lines, whitespace is preserved within a line.
+In macro lines, whitespace delimits arguments and is discarded.
.Pp
-In general, trailing whitespace on input lines is discouraged
-for reasons of clarity and portability.
+Unescaped trailing spaces are stripped from text line input unless in a
+literal context.
+In general, trailing whitespace on any input line is discouraged for
+reasons of portability.
In the rare case that a blank character is needed at the end of an
input line, it may be forced by
.Sq \e\ \e& .
.Pp
-In macro lines, whitespace delimits arguments and is discarded.
+Blank text lines, which may include whitespace, are only permitted
+within literal contexts.
+If the first character of a text line is a space, that line is printed
+with a leading newline.
.Ss Quotation
Macro arguments may be quoted with double-quotes; in this case,
whitespace within the quotes is retained as part of the argument.
.Pp
In text lines, quotes are regarded as opaque text.
.Ss Scaling Widths
-Many macros support scaled widths for their arguments, such as
-stipulating a two-inch list indentation with the following:
-.Bd -literal -offset indent
-\&.Bl -tag -width 2i
-.Ed
-.Pp
-The syntax for scaled widths is
+Many macros support scaled widths for their arguments.
+The syntax for a scaled width is
.Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
where a decimal must be preceded or proceeded by at least one digit.
Negative numbers, while accepted, are truncated to zero.
+.Pp
The following scaling units are accepted:
.Pp
.Bl -tag -width Ds -offset indent -compact
is necessarily non-portable across output media.
See
.Sx COMPATIBILITY .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \&.Bl -tag -width 2i
+two-inch tagged list indentation
+.Pq see Sx \&Bl
+.It \&.sp 2v
+two vertical spaces
+.Pq see Sx \&sp
+.El
.Ss Sentence Spacing
-When composing a manual, make sure that sentences end at the end of
-a line.
-By doing so, front-ends will be able to apply the proper amount of
+Sentences should terminate at the end of an input line.
+By doing this, a formatter 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
.Pp
The proper spacing is also intelligently preserved if a sentence ends at
the boundary of a macro line.
-For example:
.Pp
-.Dl \&.Xr mandoc 1 \&.
-.Dl \&.Fl T \&Ns \&Cm ascii \&.
+Examples:
+.Bd -literal -offset indent -compact
+Do not end sentences mid-line like this. Instead,
+end a sentence like this.
+A macro would end like this:
+\&.Xr mandoc 1 \&.
+.Ed
.Sh MANUAL STRUCTURE
A well-formed
.Nm
.Ed
.Pp
Manuals not documenting a command won't include the above fragment.
+.Pp
+Since the
+.Em DESCRIPTION
+section usually contains most of the text of a manual, longer manuals
+often use the
+.Sx \&Ss
+macro to form subsections.
+In very long manuals, the
+.Em DESCRIPTION
+may be split into multiple sections, each started by an
+.Sx \&Sh
+macro followed by a non-standard section name, and each having
+several subsections, like in the present
+.Nm
+manual.
.It Em IMPLEMENTATION NOTES
Implementation-specific notes should be kept here.
This is useful when implementing standard functions that may have side
Cross-references should conventionally be ordered first by section, then
alphabetically.
.Pp
+References to other documentation concerning the topic of the manual page,
+for example authoritative books or journal articles, may also be
+provided in this section.
+.Pp
See
+.Sx \&Rs
+and
.Sx \&Xr .
.It Em STANDARDS
References any standards implemented or used.
See
.Sx \&St .
.It Em HISTORY
-A brief history of the subject, including where support first appeared.
+A brief history of the subject, including where it was first implemented,
+and when it was ported to or reimplemented for the operating system at hand.
.It Em AUTHORS
Credits to the person or persons who wrote the code and/or documentation.
Authors should generally be noted by both name and email address.
must be one of the following:
.Bl -tag -width 13n -offset indent
.It Fl centered
-Centre-justify each line.
+Produce one output line from each input line, and 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.
+Change the positions of line breaks to fill each line, and left- and
+right-justify the resulting block.
.It Fl literal
-Do not justify the block at all.
+Produce one output line from each input line,
+and do not justify the block at all.
Preserve white space as it appears in the input.
+Always use a constant-width font.
+Use this for displaying source code.
.It Fl ragged
-Only left-justify the block.
+Change the positions of line breaks to fill each line, and left-justify
+the resulting block.
.It Fl unfilled
-An alias for
-.Fl literal .
+The same as
+.Fl literal ,
+but using the same font as for normal text, which is a variable width font
+if supported by the output device.
.El
.Pp
The
.It
One of the pre-defined strings
.Cm indent ,
-the width of standard indentation;
+the width of a standard indentation (six constant width characters);
.Cm indent-two ,
twice
.Cm indent ;
Like
.Fl inset ,
except that item heads are not parsed for macro invocations.
-.\" but with additional formatting to the head.
+Most often used in the
+.Em DIAGNOSTICS
+section with error constants in the item heads.
.It Fl enum
A numbered list.
+No item heads can be specified.
Formatted like
.Fl bullet ,
except that cardinal numbers are used in place of bullets,
Otherwise, the body starts on the output line following the head.
.El
.Pp
+Lists may be nested within lists and displays.
+Nesting of
+.Fl column
+and
+.Fl enum
+lists may not be portable.
+.Pp
See also
.Sx \&El
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:
+.Dl \&.Bx 4.3 Tahoe
.Dl \&.Bx 4.4
.Dl \&.Bx
.Pp
and
.Sx \&It .
.Ss \&Em
-Denotes text that should be emphasised.
+Denotes text that should be
+.Em emphasised .
Note that this is a presentation term and should not be used for
stylistically decorating technical terms.
+Depending on the output device, this is usually represented
+using an italic font or underlined characters.
.Pp
Examples:
.Dl \&.Em Warnings!
.Pp
See also
.Sx \&Bf ,
-.Sx \&Sy ,
+.Sx \&Li ,
+.Sx \&No ,
and
-.Sx \&Li .
+.Sx \&Sy .
.Ss \&En
This macro is obsolete and not implemented in
.Xr mandoc 1 .
output.
.Pp
Examples:
-.Dl ".Nm cat Fl v No considered harmful"
-.Dl ".Nm cp Fl pR Ar source ... directory"
-.Dl ".Nm find Ar dir Fl type Cm d Fl name Pa CVS
-.Dl ".Nm kill Fl Ar signal_number pid"
-.Dl ".Nm su Fl"
+.Dl ".Fl R Op Fl H | L | P"
+.Dl ".Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux"
+.Dl ".Fl type Cm d Fl name Pa CVS"
+.Dl ".Fl Ar signal_number"
+.Dl ".Fl o Fl"
.Pp
See also
.Sx \&Cm .
and
.Sx \&Ft .
.Ss \&Fr
-This macro is obsolete and not implemented.
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
+.Pp
+It was used to show function return values.
+The syntax was:
+.Pp
+.Dl Pf . Sx \&Fr Ar value
.Ss \&Ft
A function type.
Its syntax is as follows:
and
.Sx \&Ux .
.Ss \&Hf
-This macro is obsolete and not implemented.
+This macro is not implemented in
+.Xr mandoc 1 .
+.Pp
+It was used to include the contents of a (header) file literally.
+The syntax was:
+.Pp
+.Dl Pf . Sx \&Hf Ar filename
.Ss \&Ic
Designate an internal or interactive command.
This is similar to
.Dl \&.Lb libz
.Dl \&.Lb mdoc
.Ss \&Li
-Denotes text that should be in a literal font mode.
+Denotes text that should be in a
+.Li literal
+font mode.
Note that this is a presentation term and should not be used for
stylistically decorating technical terms.
.Pp
+On terminal output devices, this is often indistinguishable from
+normal text.
+.Pp
See also
.Sx \&Bf ,
-.Sx \&Sy ,
+.Sx \&Em ,
+.Sx \&No ,
and
-.Sx \&Em .
+.Sx \&Sy .
.Ss \&Lk
Format a hyperlink.
Its syntax is as follows:
macro.
.Pp
Examples:
-.Dl \&.Sx \&Nd mdoc language reference
-.Dl \&.Sx \&Nd format and display UNIX manuals
+.Dl Pf . Sx \&Nd mdoc language reference
+.Dl Pf . Sx \&Nd format and display UNIX manuals
.Pp
The
.Sx \&Nd
.Sx \&Nm
to mark up the name of the manual page.
.Ss \&No
-A
-.Dq noop
-macro used to terminate prior macro contexts.
+Normal text.
+Closes the scope of any preceding in-line macro.
+When used after physical formatting macros like
+.Sx \&Em
+or
+.Sx \&Sy ,
+switches back to the standard font face and weight.
+Can also be used to embed plain text strings in macro lines
+using semantic annotation macros.
.Pp
Examples:
-.Dl \&.Sx \&Fl ab \&No cd \&Fl ef
+.Dl ".Em italic , Sy bold , No and roman"
+.Pp
+.Bd -literal -offset indent -compact
+\&.Sm off
+\&.Cm :C No / Ar pattern No / Ar replacement No /
+\&.Sm on
+.Ed
+.Pp
+See also
+.Sx \&Em ,
+.Sx \&Li ,
+and
+.Sx \&Sy .
.Ss \&Ns
-Suppress a space.
-Following invocation, text is interpreted as free-form text until a
-macro is encountered.
+Suppress a space between the output of the preceding macro
+and the following text or macro.
+Following invocation, input is interpreted as normal text
+just like after an
+.Sx \&No
+macro.
.Pp
This has no effect when invoked at the start of a macro line.
.Pp
Examples:
-.Dl \&.Fl o \&Ns \&Ar output
+.Dl ".Ar name Ns = Ns Ar value"
+.Dl ".Cm :M Ns Ar pattern"
+.Dl ".Fl o Ns Ar output"
.Pp
See also
.Sx \&No
and
.Sx \&Dt .
.Ss \&Ot
-Unknown usage.
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
.Pp
-.Em Remarks :
-this macro has been deprecated.
+Historical
+.Xr mdoc 7
+packages described it as
+.Dq "old function type (FORTRAN)" .
.Ss \&Ox
Format the
.Ox
Close parenthesised context opened by
.Sx \&Po .
.Ss \&Pf
-Removes the space
+Removes the space between its argument
.Pq Dq prefix
-between its arguments.
+and the following macro.
Its syntax is as follows:
.Pp
-.D1 Pf \. \&Pf Ar prefix suffix
+.D1 .Pf Ar prefix macro arguments ...
.Pp
-The
-.Ar suffix
-argument may be a macro.
+This is equivalent to:
+.Pp
+.D1 .No Ar prefix No \&Ns Ar macro arguments ...
.Pp
Examples:
-.Dl \&.Pf \e. \&Sx \&Pf \&Ar prefix suffix
+.Dl ".Pf $ Ar variable_name"
+.Dl ".Pf 0x Ar hex_digits"
+.Pp
+See also
+.Sx \&Ns
+and
+.Sx \&Sm .
.Ss \&Po
Multi-line version of
.Sx \&Pq .
Break a paragraph.
This will assert vertical space between prior and subsequent macros
and/or text.
+.Pp
+Paragraph breaks are not needed before or after
+.Sx \&Sh
+or
+.Sx \&Ss
+macros or before displays
+.Pq Sx \&Bd
+or lists
+.Pq Sx \&Bl
+unless the
+.Fl compact
+flag is given.
.Ss \&Pq
Parenthesised enclosure.
.Pp
.Sx \&Qq .
.Ss \&Qq
Encloses its arguments in
-.Dq typewriter
+.Qq typewriter
double-quotes.
Consider using
.Sx \&Dq .
.Sx \&Sq .
.Ss \&Sq
Encloses its arguments in
-.Dq typewriter
+.Sq typewriter
single-quotes.
.Pp
See also
and
.Sx \&So .
.Ss \&Ss
-Begin a new sub-section.
+Begin a new subsection.
Unlike with
.Sx \&Sh ,
-there's no convention for sub-sections.
-Conventional sections, as described in
-.Sx MANUAL STRUCTURE ,
-rarely have sub-sections.
+there is no convention for the naming of subsections.
+Except
+.Em DESCRIPTION ,
+the conventional sections described in
+.Sx MANUAL STRUCTURE
+rarely have subsections.
.Pp
Sub-section names should be unique so that they may be keyed by
.Sx \&Sx .
.St -svid4
.El
.Ss \&Sx
-Reference a section or sub-section.
-The referenced section or sub-section name must be identical to the
+Reference a section or subsection in the same manual page.
+The referenced section or subsection name must be identical to the
enclosed argument, including whitespace.
.Pp
Examples:
.Pp
See also
.Sx \&Bf ,
+.Sx \&Em ,
.Sx \&Li ,
and
-.Sx \&Em .
+.Sx \&No .
.Ss \&Ta
Table cell separator in
.Sx \&Bl Fl column
.Ss \&Tn
Format a tradename.
.Pp
+Since this macro is often implemented to use a small caps font,
+it has historically been used for acronyms (like ASCII) as well.
+Such usage is not recommended because it would use the same macro
+sometimes for semantical annotation, sometimes for physical formatting.
+.Pp
Examples:
.Dl \&.Tn IBM
.Ss \&Ud
Prints out
-.Dq currently under development .
+.Dq currently under development.
.Ss \&Ux
Format the UNIX name.
Accepts no argument.
.Xr mandoc 1 ,
.Xr eqn 7 ,
.Xr man 7 ,
-.Xr mandoc_char 7
+.Xr mandoc_char 7 ,
.Xr roff 7 ,
.Xr tbl 7
.Sh HISTORY
The
.Nm
reference was written by
-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
+.An Kristaps Dzonsons ,
+.Mt kristaps@bsd.lv .
git.ckatri.com / mandoc.git / blobdiff