-.\" $Id: roff.7,v 1.29 2011/05/24 15:22:14 kristaps Exp $
+.\" $Id: roff.7,v 1.46 2013/12/26 02:43:18 schwarze Exp $
.\"
-.\" Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
-.\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010, 2011, 2013 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 24 2011 $
+.Dd $Mdocdate: December 26 2013 $
.Dt ROFF 7
.Os
.Sh NAME
The
.Nm roff
language is a general purpose text formatting language.
-In particular, it serves as the basis for the
+Since traditional implementations of the
.Xr mdoc 7
and
.Xr man 7
-manual formatting macro languages.
-This manual describes the subset of the
+manual formatting languages are based on it,
+many real-world manuals use small numbers of
.Nm
-language accepted by the
+requests and escape sequences intermixed with their
+.Xr mdoc 7
+or
+.Xr man 7
+code.
+To properly format such manuals, the
+.Xr mandoc 1
+utility supports a tiny subset of
+.Nm
+requests and escapes.
+Only these requests and escapes supported by
.Xr mandoc 1
-utility.
+are documented in the present manual,
+together with the basic language syntax shared by
+.Nm ,
+.Xr mdoc 7 ,
+and
+.Xr man 7 .
+For complete
+.Nm
+manuals, consult the
+.Sx SEE ALSO
+section.
.Pp
-Input lines beginning with the control characters
+Input lines beginning with the control character
.Sq \&.
-or
-.Sq \(aq
are parsed for requests and macros.
-These define the document structure, change the processing state
-and manipulate the formatting.
-Some requests and macros also produce formatted output,
-while others do not.
-.Pp
-All other input lines provide free-form text to be printed;
-the formatting of free-form text depends on the respective
-processing context.
+Such lines are called
+.Dq request lines
+or
+.Dq macro lines ,
+respectively.
+Requests change the processing state and manipulate the formatting;
+some macros also define the document structure and produce formatted
+output.
+The single quote
+.Pq Qq \(aq
+is accepted as an alternative control character,
+treated by
+.Xr mandoc 1
+just like
+.Ql \&.
+.Pp
+Lines not beginning with control characters are called
+.Dq text lines .
+They provide free-form text to be printed; the formatting of the text
+depends on the respective processing context.
.Sh LANGUAGE SYNTAX
.Nm
documents may contain only graphable 7-bit ASCII characters, the space
character, and, in certain circumstances, the tab character.
-To produce other characters in the output, use the escape sequences
-documented in the
+The backslash character
+.Sq \e
+indicates the start of an escape sequence, used for example for
+.Sx Comments ,
+.Sx Special Characters ,
+.Sx Predefined Strings ,
+and
+user-defined strings defined using the
+.Sx ds
+request.
+For a listing of escape sequences, consult the
+.Sx ESCAPE SEQUENCE REFERENCE
+below.
+.Ss Comments
+Text following an escaped double-quote
+.Sq \e\(dq ,
+whether in a request, macro, or text line, is ignored to the end of the line.
+A request line beginning with a control character and comment escape
+.Sq \&.\e\(dq
+is also ignored.
+Furthermore, request lines with only a control character and optional
+trailing whitespace are stripped from input.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.\e\(dq This is a comment line.
+\&.\e\(dq The next line is ignored:
+\&.
+\&.Sh EXAMPLES \e\(dq This is a comment, too.
+\&example text \e\(dq And so is this.
+.Ed
+.Ss Special Characters
+Special characters are used to encode special glyphs and are rendered
+differently across output media.
+They may occur in request, macro, and text lines.
+Sequences begin with the escape character
+.Sq \e
+followed by either an open-parenthesis
+.Sq \&(
+for two-character sequences; an open-bracket
+.Sq \&[
+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 Li \e(em
+Two-letter em dash escape.
+.It Li \ee
+One-letter backslash escape.
+.El
+.Pp
+See
.Xr mandoc_char 7
-manual.
+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 (regular), or P
+(revert to previous mode).
+A numerical representation 3, 2, or 1 (bold, italic, and regular,
+respectively) may be used instead.
+The indicator or numerical representative may be preceded by C
+(constant-width), which is ignored.
+.Pp
+The two-character indicator
+.Sq BI
+requests a font that is both bold and italic.
+It may not be portable to old roff implementations.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \efBbold\efR
+Write in \fBbold\fP, then switch to regular font mode.
+.It Li \efIitalic\efP
+Write in \fIitalic\fP, then return to previous font mode.
+.It Li \ef(BIbold italic\efP
+Write in \f(BIbold italic\fP, then return to previous font mode.
+.El
+.Pp
+Text decoration is
+.Em not
+recommended for
+.Xr mdoc 7 ,
+which encourages semantic annotation.
+.Ss Predefined Strings
+Predefined strings, like
+.Sx Special Characters ,
+mark special output glyphs.
+Predefined strings are escaped with the slash-asterisk,
+.Sq \e* :
+single-character
+.Sq \e*X ,
+two-character
+.Sq \e*(XX ,
+and N-character
+.Sq \e*[N] .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \e*(Am
+Two-letter ampersand predefined string.
+.It Li \e*q
+One-letter double-quote predefined string.
+.El
+.Pp
+Predefined strings are not recommended for use,
+as they differ across implementations.
+Those supported by
+.Xr mandoc 1
+are listed in
+.Xr mandoc_char 7 .
+Manuals using these predefined strings are almost certainly not portable.
+.Ss Whitespace
+Whitespace consists of the space character.
+In text lines, whitespace is preserved within a line.
+In request and macro lines, whitespace delimits arguments and is discarded.
+.Pp
+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
+Literal space characters can be produced in the output
+using escape sequences.
+In macro lines, they can also be included in arguments using quotation; see
+.Sx MACRO SYNTAX
+for details.
+.Pp
+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 Scaling Widths
+Many requests and 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 followed 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
+.It c
+centimetre
+.It i
+inch
+.It P
+pica (~1/6 inch)
+.It p
+point (~1/72 inch)
+.It f
+synonym for
+.Sq u
+.It v
+default vertical span
+.It m
+width of rendered
+.Sq m
+.Pq em
+character
+.It n
+width of rendered
+.Sq n
+.Pq en
+character
+.It u
+default horizontal span
+.It M
+mini-em (~1/100 em)
+.El
+.Pp
+Using anything other than
+.Sq m ,
+.Sq n ,
+.Sq u ,
+or
+.Sq v
+is necessarily non-portable across output media.
+See
+.Sx COMPATIBILITY .
+.Pp
+If a scaling unit is not provided, the numerical value is interpreted
+under the default rules of
+.Sq v
+for vertical spaces and
+.Sq u
+for horizontal ones.
+.Pp
+Examples:
+.Bl -tag -width ".Bl -tag -width 2i" -offset indent -compact
+.It Li \&.Bl -tag -width 2i
+two-inch tagged list indentation in
+.Xr mdoc 7
+.It Li \&.HP 2i
+two-inch tagged list indentation in
+.Xr man 7
+.It Li \&.sp 2v
+two vertical spaces
+.El
+.Ss Sentence Spacing
+Each sentence 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
+.Po
+.Sq \&) ,
+.Sq \&] ,
+.Sq \&' ,
+.Sq \&"
+.Pc .
+.Pp
+The proper spacing is also intelligently preserved if a sentence ends at
+the boundary of a macro line.
+.Pp
+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 REQUEST SYNTAX
A request or macro line consists of:
.Pp
\&. ig end
.Ed
.Sh MACRO SYNTAX
-Macros can be defined by the
+Macros are provided by the
+.Xr mdoc 7
+and
+.Xr man 7
+languages and can be defined by the
.Sx \&de
request.
When called, they follow the same syntax as requests, except that
macro arguments may optionally be quoted by enclosing them
in double quote characters
.Pq Sq \(dq .
-To be recognized as the beginning of a quoted argument, the opening
-quote character must be preceded by a space character.
-.Pp
-A quoted argument may contain whitespace, and pairs of double quote
-characters
+Quoted text, even if it contains whitespace or would cause
+a macro invocation when unquoted, is always considered literal text.
+Inside quoted text, pairs of double quote characters
.Pq Sq Qq
resolve to single double quote characters.
+.Pp
+To be recognised as the beginning of a quoted argument, the opening
+quote character must be preceded by a space character.
A quoted argument extends to the next double quote character that is not
part of a pair, or to the end of the input line, whichever comes earlier.
Leaving out the terminating double quote character at the end of the line
by preceding them with a backslash
.Pq Sq \e\~ ,
but quoting is usually better for clarity.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li .Fn strlen \(dqconst char *s\(dq
+Group arguments
+.Qq const char *s
+into one function argument.
+If unspecified,
+.Qq const ,
+.Qq char ,
+and
+.Qq *s
+would be considered separate arguments.
+.It Li .Op \(dqFl a\(dq
+Consider
+.Qq \&Fl a
+as literal text instead of a flag macro.
+.El
.Sh REQUEST REFERENCE
The
.Xr mandoc 1
.Nm
-parser recognizes the following requests.
+parser recognises the following requests.
Note that the
.Nm
language defines many more requests not implemented in
.Ss \&ad
Set line adjustment mode.
This line-scoped request is intended to have one argument to select
-normal, left, right, or center adjustment for subsequent text.
+normal, left, right, or centre adjustment for subsequent text.
Currently, it is ignored including its arguments,
and the number of arguments is not checked.
.Ss \&am
It is currently ignored by
.Xr mandoc 1 ,
as are its children.
+.Ss \&cc
+Changes the control character.
+Its syntax is as follows:
+.Bd -literal -offset indent
+.Pf . Cm \&cc Op Ar c
+.Ed
+.Pp
+If
+.Ar c
+is not specified, the control character is reset to
+.Sq \&. .
+Trailing characters are ignored.
.Ss \&de
Define a
.Nm
See
.Xr eqn 7
for a description of the equation language.
+.Ss \&fam
+Change the font family.
+This line-scoped request is intended to have one argument specifying
+the font family to be selected.
+It is a groff extension, and currently, it is ignored including its
+arguments, and the number of arguments is not checked.
+.Ss \&hw
+Specify hyphenation points in words.
+This line-scoped request is currently ignored.
.Ss \&hy
Set automatic hyphenation mode.
This line-scoped request is currently ignored.
Currently, it is ignored including its arguments,
and the number of arguments is not checked.
.Ss \&nr
-Define a register.
+Define or change a register.
A register is an arbitrary string value that defines some sort of state,
which influences parsing and/or formatting.
Its syntax is as follows:
.Pp
-.D1 Pf \. Cm \&nr Ar name Ar value
+.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar value
.Pp
The
.Ar value
may, at the moment, only be an integer.
-So far, only the following register
+If it is prefixed by a sign, the register will be
+incremented or decremented instead of assigned to.
+.Pp
+The following register
.Ar name
-is recognised:
+is handled specially:
.Bl -tag -width Ds
.It Cm nS
If set to a positive integer value, certain
.Qq ../
and
.Qq /.. .
+.Pp
+This request requires
+.Xr man 1
+to change to the right directory before calling
+.Xr mandoc 1 ,
+per convention to the root of the manual tree.
+Typical usage looks like:
+.Pp
+.Dl \&.so man3/Xcursor.3
+.Pp
+As the whole concept is rather fragile, the use of
+.Sx \&so
+is discouraged.
+Use
+.Xr ln 1
+instead.
.Ss \&ta
Set tab stops.
This line-scoped request can take an arbitrary number of arguments.
Currently, it is ignored including its arguments.
.Ss \&tr
Output character translation.
-This request is intended to have one argument,
-consisting of an even number of characters.
-Currently, it is ignored including its arguments,
-and the number of arguments is not checked.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Cm \&tr Ar [ab]+
+.Pp
+Pairs of
+.Ar ab
+characters are replaced
+.Ar ( a
+for
+.Ar b ) .
+Replacement (or origin) characters may also be character escapes; thus,
+.Pp
+.Dl tr \e(xx\e(yy
+.Pp
+replaces all invocations of \e(xx with \e(yy.
.Ss \&T&
Re-start a table layout, retaining the options of the prior table
invocation.
See
.Xr tbl 7
for a description of the tbl language.
+.Sh ESCAPE SEQUENCE REFERENCE
+The
+.Xr mandoc 1
+.Nm
+parser recognises the following escape sequences.
+Note that the
+.Nm
+language defines more escape sequences not implemented in
+.Xr mandoc 1 .
+In
+.Xr mdoc 7
+and
+.Xr man 7
+documents, using escape sequences is discouraged except for those
+described in the
+.Sx LANGUAGE SYNTAX
+section above.
+.Pp
+A backslash followed by any character not listed here
+simply prints that character itself.
+.Ss \e<newline>
+A backslash at the end of an input line can be used to continue the
+logical input line on the next physical input line, joining the text
+on both lines together as if it were on a single input line.
+.Ss \e<space>
+The escape sequence backslash-space
+.Pq Sq \e\ \&
+is an unpaddable space-sized non-breaking space character; see
+.Sx Whitespace .
+.Ss \e\(dq
+The rest of the input line is treated as
+.Sx Comments .
+.Ss \e%
+Hyphenation allowed at this point of the word; ignored by
+.Xr mandoc 1 .
+.Ss \e&
+Non-printing zero-width character; see
+.Sx Whitespace .
+.Ss \e\(aq
+Acute accent special character; use
+.Sq \e(aa
+instead.
+.Ss \e( Ns Ar cc
+.Sx Special Characters
+with two-letter names, see
+.Xr mandoc_char 7 .
+.Ss \e*[ Ns Ar name ]
+Interpolate the string with the
+.Ar name ;
+see
+.Sx Predefined Strings
+and
+.Sx ds .
+For short names, there are variants
+.No \e* Ns Ar c
+and
+.No \e*( Ns Ar cc .
+.Ss \e-
+Special character
+.Dq mathematical minus sign .
+.Ss \e[ Ns Ar name ]
+.Sx Special Characters
+with names of arbitrary length, see
+.Xr mandoc_char 7 .
+.Ss \e^
+One-twelfth em half-narrow space character, effectively zero-width in
+.Xr mandoc 1 .
+.Ss \e`
+Grave accent special character; use
+.Sq \e(ga
+instead.
+.Ss \e{
+Begin conditional input; see
+.Sx if .
+.Ss \e\(ba
+One-sixth em narrow space character, effectively zero-width in
+.Xr mandoc 1 .
+.Ss \e}
+End conditional input; see
+.Sx if .
+.Ss \e~
+Paddable non-breaking space character.
+.Ss \e0
+Digit width space character.
+.Ss \eA\(aq Ns Ar string Ns \(aq
+Anchor definition; ignored by
+.Xr mandoc 1 .
+.Ss \eB\(aq Ns Ar string Ns \(aq
+Test whether
+.Ar string
+is a numerical expession; ignored by
+.Xr mandoc 1 .
+.Ss \eb\(aq Ns Ar string Ns \(aq
+Bracket building function; ignored by
+.Xr mandoc 1 .
+.Ss \eC\(aq Ns Ar name Ns \(aq
+.Sx Special Characters
+with names of arbitrary length.
+.Ss \ec
+Interrupt text processing to insert requests or macros; ignored by
+.Xr mandoc 1 .
+.Ss \eD\(aq Ns Ar string Ns \(aq
+Draw graphics function; ignored by
+.Xr mandoc 1 .
+.Ss \ed
+Move down by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \ee
+Backslash special character.
+.Ss \eF[ Ns Ar name ]
+Switch font family (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eF Ns Ar c
+and
+.No \eF( Ns Ar cc .
+.Ss \ef[ Ns Ar name ]
+Switch to the font
+.Ar name ,
+see
+.Sx Text Decoration .
+For short names, there are variants
+.No \ef Ns Ar c
+and
+.No \ef( Ns Ar cc .
+.Ss \eg[ Ns Ar name ]
+Interpolate the format of a number register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eg Ns Ar c
+and
+.No \eg( Ns Ar cc .
+.Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
+Set the height of the current font; ignored by
+.Xr mandoc 1 .
+.Ss \eh\(aq Ns Ar number Ns \(aq
+Horizontal motion; ignored by
+.Xr mandoc 1 .
+.Ss \ek[ Ns Ar name ]
+Mark horizontal input place in register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \ek Ns Ar c
+and
+.No \ek( Ns Ar cc .
+.Ss \eL\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
+Vertical line drawing function; ignored by
+.Xr mandoc 1 .
+.Ss \el\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
+Horizontal line drawing function; ignored by
+.Xr mandoc 1 .
+.Ss \eM[ Ns Ar name ]
+Set fill (background) color (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eM Ns Ar c
+and
+.No \eM( Ns Ar cc .
+.Ss \em[ Ns Ar name ]
+Set glyph drawing color (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \em Ns Ar c
+and
+.No \em( Ns Ar cc .
+.Ss \eN\(aq Ns Ar number Ns \(aq
+Character
+.Ar number
+on the current font.
+.Ss \en[ Ns Ar name ]
+Interpolate the number register
+.Ar name .
+For short names, there are variants
+.No \en Ns Ar c
+and
+.No \en( Ns Ar cc .
+.Ss \eo\(aq Ns Ar string Ns \(aq
+Overstrike
+.Ar string ;
+ignored by
+.Xr mandoc 1 .
+.Ss \eR\(aq Ns Ar name Oo +|- Oc Ns Ar number Ns \(aq
+Set number register; ignored by
+.Xr mandoc 1 .
+.Ss \eS\(aq Ns Ar number Ns \(aq
+Slant output; ignored by
+.Xr mandoc 1 .
+.Ss \es\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
+Change point size; ignored by
+.Xr mandoc 1 .
+Alternative forms
+.No \es Ns Oo +|- Oc Ns Ar n ,
+.No \es Ns Oo +|- Oc Ns \(aq Ns Ar number Ns \(aq ,
+.No \es Ns [ Oo +|- Oc Ns Ar number ] ,
+and
+.No \es Ns Oo +|- Oc Ns [ Ar number Ns ]
+are also parsed and ignored.
+.Ss \et
+Horizontal tab; ignored by
+.Xr mandoc 1 .
+.Ss \eu
+Move up by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \eV[ Ns Ar name ]
+Interpolate an environment variable; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eV Ns Ar c
+and
+.No \eV( Ns Ar cc .
+.Ss \ev\(aq Ns Ar number Ns \(aq
+Vertical motion; ignored by
+.Xr mandoc 1 .
+.Ss \ew\(aq Ns Ar string Ns \(aq
+Interpolate the width of the
+.Ar string ;
+ignored by
+.Xr mandoc 1 .
+.Ss \eX\(aq Ns Ar string Ns \(aq
+Output
+.Ar string
+as device control function; ignored in nroff mode and by
+.Xr mandoc 1 .
+.Ss \ex\(aq Ns Ar number Ns \(aq
+Extra line space function; ignored by
+.Xr mandoc 1 .
+.Ss \eY[ Ns Ar name ]
+Output a string as a device control function; ignored in nroff mode and by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eY Ns Ar c
+and
+.No \eY( Ns Ar cc .
+.Ss \eZ\(aq Ns Ar string Ns \(aq
+Print
+.Ar string
+with zero width and height; ignored by
+.Xr mandoc 1 .
+.Ss \ez
+Output the next character without advancing the cursor position;
+approximated in
+.Xr mandoc 1
+by simply skipping the next character.
.Sh COMPATIBILITY
-This section documents compatibility between mandoc and other other
+This section documents compatibility between mandoc and other
.Nm
implementations, at this time limited to GNU troff
.Pq Qq groff .
.%U http://heirloom.sourceforge.net/doctools/troff.pdf
.Re
.Sh HISTORY
-The RUNOFF typesetting system was written in PL/1 for the CTSS
-operating system by Jerome ("Jerry") E. Saltzer in 1961.
-It was first used as the main documentation tool by Multics since 1963.
-Robert ("Bob") H. Morris ported it to the GE-635 and called it
+The RUNOFF typesetting system, whose input forms the basis for
.Nm ,
-Doug McIlroy rewrote it in BCPL in 1969,
-Joseph F. Ossanna rewrote it in PDP-11 assembly in 1973,
-and Brian W. Kernighan rewrote it in C in 1975.
+was written in MAD and FAP for the CTSS operating system by Jerome E.
+Saltzer in 1964.
+Doug McIlroy rewrote it in BCPL in 1969, renaming it
+.Nm .
+Dennis M. Ritchie rewrote McIlroy's
+.Nm
+in PDP-11 assembly for
+.At v1 ,
+Joseph F. Ossanna improved roff and renamed it nroff
+for
+.At v2 ,
+then ported nroff to C as troff, which Brian W. Kernighan released with
+.At v7 .
+In 1989, James Clarke re-implemented troff in C++, naming it groff.
.Sh AUTHORS
.An -nosplit
-This partial
+This
.Nm
reference was written by
-.An Kristaps Dzonsons Aq kristaps@bsd.lv
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
and
-.An Ingo Schwarze Aq schwarze@openbsd.org .
+.An Ingo Schwarze Aq Mt schwarze@openbsd.org .
git.ckatri.com / mandoc.git / blobdiff