NAME
roff
—
roff language reference for
mandoc
DESCRIPTION
The roff
language is a general purpose
text formatting language. Since traditional implementations of the
mdoc(7) and man(7) manual formatting languages are based on it, many
real-world manuals use small numbers of roff
requests and escape sequences intermixed with their
mdoc(7) or man(7) code. To properly format such manuals, the
mandoc(1) utility supports a tiny subset of
roff
requests and escapes. Only these requests and
escapes supported by
mandoc(1) are documented in the present manual, together with the
basic language syntax shared by roff
,
mdoc(7), and man(7). For complete roff
manuals,
consult the SEE ALSO section.
Input lines beginning with the control character ‘.’
are parsed for requests and macros. Such lines are called “request
lines” or “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
("'") is accepted as an alternative control character, treated by
mandoc(1) just like ‘.
’
Lines not beginning with control characters are called “text lines”. They provide free-form text to be printed; the formatting of the text depends on the respective processing context.
LANGUAGE SYNTAX
roff
documents may contain only graphable
7-bit ASCII characters, the space character, and, in certain circumstances,
the tab character. The backslash character ‘\’ indicates the
start of an escape sequence, used for example for
Comments,
Special Characters,
Predefined Strings, and
user-defined strings defined using the ds
request. For a listing of escape sequences, consult the
ESCAPE SEQUENCE
REFERENCE below.
Comments
Text following an escaped double-quote ‘\"’, 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 ‘.\"’ is also ignored. Furthermore, request lines with only a control character and optional trailing whitespace are stripped from input.
Examples:
.\" This is a comment line. .\" The next line is ignored: . .Sh EXAMPLES \" This is a comment, too. example text \" And so is this.
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 ‘\’ followed by either an open-parenthesis ‘(’ for two-character sequences; an open-bracket ‘[’ for n-character sequences (terminated at a close-bracket ‘]’); or a single one character sequence.
Examples:
See mandoc_char(7) for a complete list.
Text Decoration
Terms may be text-decorated using the ‘\f’ 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 two-character indicator ‘BI’ requests a font that is both bold and italic. It may not be portable to old roff implementations.
Examples:
\fBbold\fR
- Write in bold, then switch to regular font mode.
\fIitalic\fP
- Write in italic, then return to previous font mode.
\f(BIbold italic\fP
- Write in bold italic, then return to previous font mode.
Text decoration is not recommended for mdoc(7), which encourages semantic annotation.
Predefined Strings
Predefined strings, like Special Characters, mark special output glyphs. Predefined strings are escaped with the slash-asterisk, ‘\*’: single-character ‘\*X’, two-character ‘\*(XX’, and N-character ‘\*[N]’.
Examples:
Predefined strings are not recommended for use, as they differ across implementations. Those supported by mandoc(1) are listed in mandoc_char(7). Manuals using these predefined strings are almost certainly not portable.
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.
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 ‘\ \&’.
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 MACRO SYNTAX for details.
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.
Scaling Widths
Many requests and macros support scaled widths for their
arguments. The syntax for a scaled width is
‘[+-]?[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.
The following scaling units are accepted:
- c
- centimetre
- i
- inch
- P
- pica (~1/6 inch)
- p
- point (~1/72 inch)
- f
- scale ‘u’ by 65536
- v
- default vertical span
- m
- width of rendered ‘m’ (em) character
- n
- width of rendered ‘n’ (en) character
- u
- default horizontal span for the terminal
- M
- mini-em (~1/100 em)
Using anything other than ‘m’, ‘n’, or ‘v’ is necessarily non-portable across output media. See COMPATIBILITY.
If a scaling unit is not provided, the numerical value is interpreted under the default rules of ‘v’ for vertical spaces and ‘u’ for horizontal ones.
Examples:
.Bl -tag -width 2i
- two-inch tagged list indentation in mdoc(7)
.HP 2i
- two-inch tagged list indentation in man(7)
.sp 2v
- two vertical spaces
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 (‘)’, ‘]’, ‘'’, ‘"’).
The proper spacing is also intelligently preserved if a sentence ends at the boundary of a macro line.
Examples:
Do not end sentences mid-line like this. Instead, end a sentence like this. A macro would end like this: .Xr mandoc 1 .
REQUEST SYNTAX
A request or macro line consists of:
- the control character ‘.’ or ‘'’ at the beginning of the line,
- optionally an arbitrary amount of whitespace,
- the name of the request or the macro, which is one word of arbitrary length, terminated by whitespace,
- and zero or more arguments delimited by whitespace.
Thus, the following request lines are all equivalent:
.ig end .ig end . ig end
MACRO SYNTAX
Macros are provided by the mdoc(7) and man(7) languages and can be defined by the 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 (‘"’). 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 (‘""’) resolve to single double quote characters.
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 is discouraged. For clarity, if more arguments follow on the same input line, it is recommended to follow the terminating double quote character by a space character; in case the next character after the terminating double quote character is anything else, it is regarded as the beginning of the next, unquoted argument.
Both in quoted and unquoted arguments, pairs of backslashes (‘\\’) resolve to single backslashes. In unquoted arguments, space characters can alternatively be included by preceding them with a backslash (‘\ ’), but quoting is usually better for clarity.
Examples:
.Fn strlen "const char *s"
- Group arguments "const char *s" into one function argument. If unspecified, "const", "char", and "*s" would be considered separate arguments.
.Op "Fl a"
- Consider "Fl a" as literal text instead of a flag macro.
REQUEST REFERENCE
The mandoc(1) roff
parser recognises the
following requests. For requests marked as "ignored" or
"unsupported", any arguments are ignored, and the number of
arguments is not checked.
ab
[message]- Abort processing. Currently unsupported.
ad
[b
|c
|l
|n
|r
]- Set line adjustment mode for subsequent text. Currently ignored.
af
registername format- Assign an output format to a number register. Currently ignored.
aln
newname oldname- Create an alias for a number register. Currently unsupported.
als
newname oldname- Create an alias for a request, string, macro, or diversion.
am
macroname [endmacro]- Append to a macro definition. The syntax of this request is the same as
that of
de
. am1
macroname [endmacro]- Append to a macro definition, switching roff compatibility mode off during
macro execution (groff extension). The syntax of this request is the same
as that of
de1
. Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias foram
. ami
macrostring [endstring]- Append to a macro definition, specifying the macro name indirectly (groff
extension). The syntax of this request is the same as that of
dei
. ami1
macrostring [endstring]- Append to a macro definition, specifying the macro name indirectly and
switching roff compatibility mode off during macro execution (groff
extension). The syntax of this request is the same as that of
dei1
. Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias forami
. as
stringname [string]- Append to a user-defined string. The syntax of this request is the same as that of ds. If a user-defined string with the specified name does not yet exist, it is set to the empty string before appending.
as1
stringname [string]- Append to a user-defined string, switching roff compatibility mode off
during macro execution (groff extension). The syntax of this request is
the same as that of
ds1
. Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias foras
. asciify
divname- Fully unformat a diversion. Currently unsupported.
backtrace
- Print a backtrace of the input stack. This is a groff extension and currently ignored.
bd
font [curfont] [offset]- Artificially embolden by repeated printing with small shifts. Currently ignored.
bleedat
left top width height- Set the BleedBox page parameter for PDF generation. This is a Heirloom extension and currently ignored.
blm
macroname- Set a blank line trap. Currently unsupported.
box
divname- Begin a diversion without including a partially filled line. Currently unsupported.
boxa
divname- Add to a diversion without including a partially filled line. Currently unsupported.
bp
[+
|-
]pagenumber- Begin a new page. Currently ignored.
BP
source height width position offset flags label- Define a frame and place a picture in it. This is a Heirloom extension and currently unsupported.
br
- Break the output line.
break
- Break out of a
while
loop. Currently unsupported. breakchar
char ...- Optional line break characters. This is a Heirloom extension and currently ignored.
brnl
N- Break output line after the next N input lines. This is a Heirloom extension and currently ignored.
brp
- Break and spread output line. Currently, this is implemented as an alias
for
br
. brpnl
N- Break and spread output line after the next N input lines. This is a Heirloom extension and currently ignored.
c2
[char]- Change the no-break control character. Currently unsupported.
cc
[char]- Change the control character. If char is not specified, the control character is reset to ‘.’. Trailing characters are ignored.
ce
[N]- Center the next N input lines without filling. N defaults to 1. An argument of 0 or less ends centering. Currently, high level macros abort centering.
cf
filename- Output the contents of a file. Ignored because insecure.
cflags
flags char ...- Set character flags. This is a groff extension and currently ignored.
ch
macroname [dist]- Change a trap location. Currently ignored.
char
glyphname [string]- Define a new glyph. Currently unsupported.
chop
stringname- Remove the last character from a macro, string, or diversion. Currently unsupported.
class
classname char ...- Define a character class. This is a groff extension and currently ignored.
close
streamname- Close an open file. Ignored because insecure.
CL
color text- Print text in color. This is a Heirloom extension and currently unsupported.
color
[1
|0
]- Activate or deactivate colors. This is a groff extension and currently ignored.
composite
from to- Define a name component for composite glyph names. This is a groff extension and currently unsupported.
continue
- Immediately start the next iteration of a
while
loop. Currently unsupported. cp
[1
|0
]- Switch
roff
compatibility mode on or off. Currently ignored. cropat
left top width height- Set the CropBox page parameter for PDF generation. This is a Heirloom extension and currently ignored.
cs
font [width [emsize]]- Constant character spacing mode. Currently ignored.
cu
[N]- Underline next N input lines including whitespace. Currently ignored.
da
divname- Append to a diversion. Currently unsupported.
dch
macroname [dist]- Change a trap location in the current diversion. This is a Heirloom extension and currently unsupported.
de
macroname [endmacro]- Define a
roff
macro. Its syntax can be either.
de
macroname definition ..or
.
de
macroname endmacro definition .endmacroBoth forms define or redefine the macro macroname to represent the definition, which may consist of one or more input lines, including the newline characters terminating each line, optionally containing calls to
roff
requests,roff
macros or high-level macros like man(7) or mdoc(7) macros, whichever applies to the document in question.Specifying a custom endmacro macro works in the same way as for
ig
; namely, the call to ‘.endmacro’ first ends the definition, and after that, it is also evaluated as aroff
request orroff
macro, but not as a high-level macro.The macro can be invoked later using the syntax
.macroname [argument [argument ...]]Regarding argument parsing, see MACRO SYNTAX above.
The line invoking the macro will be replaced in the input stream by the definition, replacing all occurrences of \\$N, where N is a digit, by the Nth argument. For example,
.de ZN \fI\^\\$1\^\fP\\$2 .. .ZN XtFree .
produces
\fI\^XtFree\^\fP.in the input stream, and thus in the output: XtFree. Each occurrence of \\$* is replaced with all the arguments, joined together with single blank characters.
Since macros and user-defined strings share a common string table, defining a macro macroname clobbers the user-defined string macroname, and the definition can also be printed using the ‘\*’ string interpolation syntax described below
ds
, but this is rarely useful because every macro definition contains at least one explicit newline character.In order to prevent endless recursion, both groff and mandoc(1) limit the stack depth for expanding macros and strings to a large, but finite number, and mandoc(1) also limits the length of the expanded input line. Do not rely on the exact values of these limits.
de1
macroname [endmacro]- Define a
roff
macro that will be executed withroff
compatibility mode switched off during macro execution. This is a groff extension. Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias forde
. defcolor
newname scheme component ...- Define a color name. This is a groff extension and currently ignored.
dei
macrostring [endstring]- Define a
roff
macro, specifying the macro name indirectly (groff extension). The syntax of this request is the same as that ofde
. The effect is the same as:.de
\*[macrostring] [\*[endstring]] dei1
macrostring [endstring]- Define a
roff
macro that will be executed withroff
compatibility mode switched off during macro execution, specifying the macro name indirectly (groff extension). Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias fordei
. device
string ...devicem
stringname- These two requests only make sense with the groff-specific intermediate output format and are unsupported.
di
divname- Begin a diversion. Currently unsupported.
do
command [argument ...]- Execute
roff
request or macro line with compatibility mode disabled. Currently unsupported. ds
stringname [["]string]- Define a user-defined string. The stringname and
string arguments are space-separated. If the
string begins with a double-quote character, that
character will not be part of the string. All remaining characters on the
input line form the string, including whitespace and
double-quote characters, even trailing ones.
The string can be interpolated into subsequent text by using \*[stringname] for a stringname of arbitrary length, or \*(NN or \*N if the length of stringname is two or one characters, respectively. Interpolation can be prevented by escaping the leading backslash; that is, an asterisk preceded by an even number of backslashes does not trigger string interpolation.
Since user-defined strings and macros share a common string table, defining a string stringname clobbers the macro stringname, and the stringname used for defining a string can also be invoked as a macro, in which case the following input line will be appended to the string, forming a new input line passed to the
roff
parser. For example,.ds badidea .S .badidea H SYNOPSIS
invokes the
SH
macro when used in a man(7) document. Such abuse is of course strongly discouraged. ds1
stringname [["]string]- Define a user-defined string that will be expanded with
roff
compatibility mode switched off during string expansion. This is a groff extension. Since mandoc(1) does not implementroff
compatibility mode at all, it handles this request as an alias fords
. dwh
dist macroname- Set a location trap in the current diversion. This is a Heirloom extension and currently unsupported.
dt
[dist macroname]- Set a trap within a diversion. Currently unsupported.
ec
[char]- Enable the escape mechanism and change the escape character. The char argument defaults to the backslash (‘\’).
ecr
- Restore the escape character. Currently unsupported.
ecs
- Save the escape character. Currently unsupported.
el
body- The “else” half of an if/else conditional. Pops a result off
the stack of conditional evaluations pushed by
ie
and uses it as its conditional. If no stack entries are present (e.g., due to no priorie
calls) then false is assumed. The syntax of this request is similar toif
except that the conditional is missing. em
macroname- Set a trap at the end of input. Currently unsupported.
EN
- End an equation block. See
EQ
. eo
- Disable the escape mechanism completely.
EP
- End a picture started by
BP
. This is a Heirloom extension and currently unsupported. EQ
- Begin an equation block. See eqn(7) for a description of the equation language.
errprint
message- Print a string like an error message. This is a Heirloom extension and currently ignored.
ev
[envname]- Switch to another environment. Currently unsupported.
evc
[envname]- Copy an environment into the current environment. Currently unsupported.
ex
- Abort processing and exit. Currently unsupported.
fallback
curfont font ...- Select the fallback sequence for a font. This is a Heirloom extension and currently ignored.
fam
[familyname]- Change the font family. This is a groff extension and currently ignored.
fc
[delimchar [padchar]]- Define a delimiting and a padding character for fields. Currently unsupported.
fchar
glyphname [string]- Define a fallback glyph. Currently unsupported.
fcolor
colorname- Set the fill color for \D objects. This is a groff extension and currently ignored.
fdeferlig
font string ...- Defer ligature building. This is a Heirloom extension and currently ignored.
feature
+
|-
name- Enable or disable an OpenType feature. This is a Heirloom extension and currently ignored.
fi
- Switch to fill mode. See man(7). Ignored in mdoc(7).
fkern
font minkern- Control the use of kerning tables for a font. This is a Heirloom extension and currently ignored.
fl
- Flush output. Currently ignored.
flig
font string char ...- Define ligatures. This is a Heirloom extension and currently ignored.
fp
position font [filename]- Assign font position. Currently ignored.
fps
mapname ...- Mount a font with a special character map. This is a Heirloom extension and currently ignored.
fschar
font glyphname [string]- Define a font-specific fallback glyph. This is a groff extension and currently unsupported.
fspacewidth
font [afmunits]- Set a font-specific width for the space character. This is a Heirloom extension and currently ignored.
fspecial
curfont [font ...]- Conditionally define a special font. This is a groff extension and currently ignored.
ft
[font]- Change the font. The following font arguments are
supported:
This request takes effect only locally and may be overridden by macros and escape sequences.
ftr
newname [oldname]- Translate font name. This is a groff extension and currently ignored.
fzoom
font [permille]- Zoom font size. Currently ignored.
gcolor
[colorname]- Set glyph color. This is a groff extension and currently ignored.
hc
[char]- Set the hyphenation character. Currently ignored.
hcode
char code ...- Set hyphenation codes of characters. Currently ignored.
hidechar
font char ...- Hide characters in a font. This is a Heirloom extension and currently ignored.
hla
language- Set hyphenation language. This is a groff extension and currently ignored.
hlm
[number]- Set maximum number of consecutive hyphenated lines. Currently ignored.
hpf
filename- Load hyphenation pattern file. This is a groff extension and currently ignored.
hpfa
filename- Load hyphenation pattern file, appending to the current patterns. This is a groff extension and currently ignored.
hpfcode
code code ...- Define mapping values for character codes in hyphenation patterns. This is a groff extension and currently ignored.
hw
word ...- Specify hyphenation points in words. Currently ignored.
hy
[mode]- Set automatic hyphenation mode. Currently ignored.
hylang
language- Set hyphenation language. This is a Heirloom extension and currently ignored.
hylen
nchar- Minimum word length for hyphenation. This is a Heirloom extension and currently ignored.
hym
[length]- Set hyphenation margin. This is a groff extension and currently ignored.
hypp
penalty ...- Define hyphenation penalties. This is a Heirloom extension and currently ignored.
hys
[length]- Set hyphenation space. This is a groff extension and currently ignored.
ie
condition body- The “if” half of an if/else conditional. The result of the
conditional is pushed into a stack used by subsequent invocations of
el
, which may be separated by any intervening input (or not exist at all). Its syntax is equivalent toif
. if
condition body- Begin a conditional. This request can also be written as follows:
.
if
condition \{body body ...\}.
if
condition \{\ body ... .\}The condition is a boolean expression. Currently, mandoc(1) supports the following subset of roff conditionals:
- If ‘!’ is prefixed to condition, it is logically inverted.
- If the first character of condition is ‘n’ (nroff mode) or ‘o’ (odd page), it evaluates to true.
- If the first character of condition is ‘c’ (character available), ‘e’ (even page), ‘t’ (troff mode), or ‘v’ (vroff mode), it evaluates to false.
- If the first character of condition is ‘d’, it evaluates to true if the rest of condition is the name of an existing user defined macro or string; otherwise, it evaluates to false.
- If the first character of condition is ‘r’, it evaluates to true if the rest of condition is the name of an existing number register; otherwise, it evaluates to false.
- If the condition starts with a parenthesis or with an optionally signed integer number, it is evaluated according to the rules of Numerical expressions explained below. It evaluates to true if the result is positive, or to false if the result is zero or negative.
- Otherwise, the first character of condition is regarded as a delimiter and it evaluates to true if the string extending from its first to its second occurrence is equal to the string extending from its second to its third occurrence.
- If condition cannot be parsed, it evaluates to false.
If a conditional is false, its children are not processed, but are syntactically interpreted to preserve the integrity of the input document. Thus,
.if t .igwill discard the ‘.ig’, which may lead to interesting results, but
.if t .if t \{\will continue to syntactically interpret to the block close of the final conditional. Sub-conditionals, in this case, obviously inherit the truth value of the parent.
If the body section is begun by an escaped brace ‘\{’, scope continues until the end of the input line containing the matching closing-brace escape sequence ‘\}’. If the body is not enclosed in braces, scope continues until the end of the line. If the condition is followed by a body on the same line, whether after a brace or not, then requests and macros must begin with a control character. It is generally more intuitive, in this case, to write
.
if
condition \{\ .request .\}than having the request or macro follow as
.if
condition \{.requestThe scope of a conditional is always parsed, but only executed if the conditional evaluates to true.
Note that the ‘\}’ is converted into a zero-width escape sequence if not passed as a standalone macro ‘.\}’. For example,
.Fl a \} bwill result in ‘\}’ being considered an argument of the ‘Fl’ macro.
ig
[endmacro]- Ignore input. Its syntax can be either
.
ig
ignored text ..or
.
ig
endmacro ignored text .endmacroIn the first case, input is ignored until a ‘..’ request is encountered on its own line. In the second case, input is ignored until the specified ‘.endmacro’ is encountered. Do not use the escape character ‘\’ anywhere in the definition of endmacro; it would cause very strange behaviour.
When the endmacro is a roff request or a roff macro, like in
.ig ifthe subsequent invocation of
if
will first terminate the ignored text, then be invoked as usual. Otherwise, it only terminates the ignored text, and arguments following it or the ‘..’ request are discarded. in
[[+
|-
]width]- Change indentation. See man(7). Ignored in mdoc(7).
index
register stringname substring- Find a substring in a string. This is a Heirloom extension and currently unsupported.
it
expression macro- Set an input line trap. The named macro will be invoked after processing the number of input text lines specified by the numerical expression. While evaluating the expression, the unit suffixes described below Scaling Widths are ignored.
it
expression macro- Set an input line trap, not counting lines ending with \c. Currently unsupported.
IX
class keystring- To support the generation of a table of contents, pod2man(1) emits this user-defined macro, usually without defining it. To avoid reporting large numbers of spurious errors, mandoc(1) ignores it.
kern
[1
|0
]- Switch kerning on or off. Currently ignored.
kernafter
font char ... afmunits ...- Increase kerning after some characters. This is a Heirloom extension and currently ignored.
kernbefore
font char ... afmunits ...- Increase kerning before some characters. This is a Heirloom extension and currently ignored.
kernpair
font char ... font char ... afmunits- Add a kerning pair to the kerning table. This is a Heirloom extension and currently ignored.
lc
[glyph]- Define a leader repetition character. Currently unsupported.
lc_ctype
localename- Set the
LC_CTYPE
locale. This is a Heirloom extension and currently unsupported. lds
macroname string- Define a local string. This is a Heirloom extension and currently unsupported.
length
register string- Count the number of input characters in a string. Currently unsupported.
letadj
lspmin lshmin letss lspmax lshmax- Dynamic letter spacing and reshaping. This is a Heirloom extension and currently ignored.
lf
lineno [filename]- Change the line number for error messages. Ignored because insecure.
lg
[1
|0
]- Switch the ligature mechanism on or off. Currently ignored.
lhang
font char ... afmunits- Hang characters at left margin. This is a Heirloom extension and currently ignored.
linetabs
[1
|0
]- Enable or disable line-tabs mode. This is a groff extension and currently unsupported.
ll
[[+
|-
]width]- Change the output line length. If the width argument
is omitted, the line length is reset to its previous value. The default
setting for terminal output is 78n. If a sign is given, the line length is
added to or subtracted from; otherwise, it is set to the provided value.
Using this request in new manuals is discouraged for several reasons,
among others because it overrides the
mandoc(1)
-O
width
command line option. lnr
register [+
|-
]value [increment]- Set local number register. This is a Heirloom extension and currently unsupported.
lnrf
register [+
|-
]value [increment]- Set local floating-point register. This is a Heirloom extension and currently unsupported.
lpfx
string- Set a line prefix. This is a Heirloom extension and currently unsupported.
ls
[factor]- Set line spacing. It takes one integer argument specifying the vertical distance of subsequent output text lines measured in v units. Currently ignored.
lsm
macroname- Set a leading spaces trap. This is a groff extension and currently unsupported.
lt
[[+
|-
]width]- Set title line length. Currently ignored.
mc
glyph [dist]- Print margin character in the right margin. The dist is currently ignored; instead, 1n is used.
mediasize
media- Set the device media size. This is a Heirloom extension and currently ignored.
minss
width- Set minimum word space. This is a Heirloom extension and currently ignored.
mk
[register]- Mark vertical position. Currently ignored.
mso
filename- Load a macro file using the search path. Ignored because insecure.
na
- Disable adjusting without changing the adjustment mode. Currently ignored.
ne
[height]- Declare the need for the specified minimum vertical space before the next trap or the bottom of the page. Currently ignored.
nf
- Switch to no-fill mode. See man(7). Ignored by mdoc(7).
nh
- Turn off automatic hyphenation mode. Currently ignored.
nhychar
char ...- Define hyphenation-inhibiting characters. This is a Heirloom extension and currently ignored.
nm
[start [inc [space [indent]]]]- Print line numbers. Currently unsupported.
nn
[number]- Temporarily turn off line numbering. Currently unsupported.
nop
body- Execute the rest of the input line as a request or macro line. Currently unsupported.
nr
register [+
|-
]expression- Define or change a register. A register is an arbitrary string value that
defines some sort of state, which influences parsing and/or formatting.
For the syntax of expression, see
Numerical expressions
below. If it is prefixed by a sign, the register will be incremented or
decremented instead of assigned to.
The following register is handled specially:
nS
- If set to a positive integer value, certain
mdoc(7) macros will behave in the same way as in the
SYNOPSIS section. If set to 0, these macros will
behave in the same way as outside the SYNOPSIS
section, even when called within the SYNOPSIS
section itself. Note that starting a new
mdoc(7) section with the
Sh
macro will reset this register.
nrf
register [+
|-
]expression [increment]- Define or change a floating-point register. This is a Heirloom extension and currently unsupported.
nroff
- Force nroff mode. This is a groff extension and currently ignored.
ns
- Turn on no-space mode. Currently ignored.
nx
[filename]- Abort processing of the current input file and process another one. Ignored because insecure.
open
stream file- Open a file for writing. Ignored because insecure.
opena
stream file- Open a file for appending. Ignored because insecure.
os
- Output saved vertical space. Currently ignored.
output
string- Output directly to intermediate output. Not supported.
padj
[1
|0
]- Globally control paragraph-at-once adjustment. This is a Heirloom extension and currently ignored.
papersize
media- Set the paper size. This is a Heirloom extension and currently ignored.
pc
[char]- Change the page number character. Currently ignored.
pev
- Print environments. This is a groff extension and currently ignored.
pi
command- Pipe output to a shell command. Ignored because insecure.
PI
- Low-level request used by
BP
. This is a Heirloom extension and currently unsupported. pl
[[+
|-
]height]- Change page length. Currently ignored.
pm
- Print names and sizes of macros, strings, and diversions to standard error output. Currently ignored.
pn
[+
|-
]number- Change the page number of the next page. Currently ignored.
pnr
- Print all number registers on standard error output. Currently ignored.
po
[[+
|-
]offset]- Set a horizontal page offset. If no argument is specified, the page offset
is reverted to its previous value. If a sign is specified, the new page
offset is calculated relative to the current one; otherwise, it is
absolute. The argument follows the syntax of
Scaling Widths and the default
scaling unit is
m
. ps
[[+
|-
]size]- Change point size. Currently ignored.
psbb
filename- Retrieve the bounding box of a PostScript file. Currently unsupported.
pshape
indent length ...- Set a special shape for the current paragraph. This is a Heirloom extension and currently unsupported.
pso
command- Include output of a shell command. Ignored because insecure.
ptr
- Print the names and positions of all traps on standard error output. This is a groff extension and currently ignored.
pvs
[[+
|-
]height]- Change post-vertical spacing. This is a groff extension and currently ignored.
rchar
glyph ...- Remove glyph definitions. Currently unsupported.
rd
[prompt [agument ...]]- Read from standard input. Currently ignored.
recursionlimit
maxrec maxtail- Set the maximum stack depth for recursive macros. This is a Heirloom extension and currently ignored.
return
[twice]- Exit a macro and return to the caller. Currently unsupported.
rfschar
font glyph ...- Remove font-specific fallback glyph definitions. Currently unsupported.
rhang
font char ... afmunits- Hang characters at right margin. This is a Heirloom extension and currently ignored.
rj
[N]- Justify the next N input lines to the right margin without filling. N defaults to 1. An argument of 0 or less ends right adjustment.
rm
macroname- Remove a request, macro or string.
rn
oldname newname- Rename a request, macro, diversion, or string. In
mandoc(1), user-defined macros,
mdoc(7) and
man(7) macros, and user-defined strings can be renamed, but
renaming of predefined strings and of
roff
requests is not supported, and diversions are not implemented at all. rnn
oldname newname- Rename a number register. Currently unsupported.
rr
register- Remove a register.
rs
- End no-space mode. Currently ignored.
rt
[dist]- Return to marked vertical position. Currently ignored.
schar
glyph [string]- Define global fallback glyph. This is a groff extension and currently unsupported.
sentchar
char ...- Define sentence-ending characters. This is a Heirloom extension and currently ignored.
shc
[glyph]- Change the soft hyphen character. Currently ignored.
shift
[number]- Shift macro arguments. Currently unsupported.
sizes
size ...- Define permissible point sizes. This is a groff extension and currently ignored.
so
filename- Include a source file. The file is read and its contents processed as
input in place of the
so
request line. To avoid inadvertent inclusion of unrelated files, mandoc(1) only accepts relative paths not containing the strings "../" and "/..".This request requires man(1) to change to the right directory before calling mandoc(1), per convention to the root of the manual tree. Typical usage looks like:
.so man3/Xcursor.3
As the whole concept is rather fragile, the use of
so
is discouraged. Use ln(1) instead. sp
[height]- Break the output line and emit vertical space. The argument follows the
syntax of Scaling Widths and
defaults to one blank line (
1v
). spacewidth
[1
|0
]- Set the space width from the font metrics file. This is a Heirloom extension and currently ignored.
special
[font ...]- Define a special font. This is a groff extension and currently ignored.
spreadwarn
[width]- Warn about wide spacing between words. Currently ignored.
ss
wordspace [sentencespace]- Set space character size. Currently ignored.
sty
position style- Associate style with a font position. This is a groff extension and currently ignored.
substring
stringname startpos [endpos]- Replace a user-defined string with a substring. Currently unsupported.
sv
[height]- Save vertical space. Currently ignored.
sy
command- Execute shell command. Ignored because insecure.
T&
- Re-start a table layout, retaining the options of the prior table invocation. See TS.
ta
[width ... [T
width ...]]- Set tab stops. Each width argument follows the
syntax of Scaling Widths. If
prefixed by a plus sign, it is relative to the previous tab stop. The
arguments after the
T
marker are used repeatedly as often as needed; for each reuse, they are taken relative to the last previously established tab stop. Whenta
is called without arguments, all tab stops are cleared. tc
[glyph]- Change tab repetition character. Currently unsupported.
TE
- End a table context. See TS.
ti
[+
|-
]width- Break the output line and indent the next output line by
width. If a sign is specified, the temporary
indentation is calculated relative to the current indentation; otherwise,
it is absolute. The argument follows the syntax of
Scaling Widths and the default
scaling unit is
m
. tkf
font minps width1 maxps width2- Enable track kerning for a font. Currently ignored.
tl
'left'center'right'- Print a title line. Currently unsupported.
tm
string- Print to standard error output. Currently ignored.
tm1
string- Print to standard error output, allowing leading blanks. This is a groff extension and currently ignored.
tmc
string- Print to standard error output without a trailing newline. This is a groff extension and currently ignored.
tr
glyph glyph ...- Output character translation. The first glyph in each pair is replaced by
the second one. Character escapes can be used; for example,
tr \(xx\(yy
replaces all invocations of \(xx with \(yy.
track
font minps width1 maxps width2- Static letter space tracking. This is a Heirloom extension and currently ignored.
transchar
char ...- Define transparent characters for sentence-ending. This is a Heirloom extension and currently ignored.
trf
filename- Output the contents of a file, disallowing invalid characters. This is a groff extension and ignored because insecure.
trimat
left top width height- Set the TrimBox page parameter for PDF generation. This is a Heirloom extension and currently ignored.
trin
glyph glyph ...- Output character translation, ignored by
asciify
. Currently unsupported. trnt
glyph glyph ...- Output character translation, ignored by \!. Currently unsupported.
troff
- Force troff mode. This is a groff extension and currently ignored.
TS
- Begin a table, which formats input in aligned rows and columns. See tbl(7) for a description of the tbl language.
uf
font- Globally set the underline font. Currently ignored.
ul
[N]- Underline next N input lines. Currently ignored.
unformat
divname- Unformat spaces and tabs in a diversion. Currently unsupported.
unwatch
macroname- Disable notification for string or macro. This is a Heirloom extension and currently ignored.
unwatchn
register- Disable notification for register. This is a Heirloom extension and currently ignored.
vpt
[1
|0
]- Enable or disable vertical position traps. This is a groff extension and currently ignored.
vs
[[+
|-
]height]- Change vertical spacing. Currently ignored.
warn
flags- Set warning level. Currently ignored.
warnscale
si- Set the scaling indicator used in warnings. This is a groff extension and currently ignored.
watch
macroname- Notify on change of string or macro. This is a Heirloom extension and currently ignored.
watchlength
maxlength- On change, report the contents of macros and strings up to the specified length. This is a Heirloom extension and currently ignored.
watchn
register- Notify on change of register. This is a Heirloom extension and currently ignored.
wh
dist [macroname]- Set a page location trap. Currently unsupported.
while
condition body- Repeated execution while a condition is true. Currently unsupported.
write
["]string- Write to an open file. Ignored because insecure.
writec
["]string- Write to an open file without appending a newline. Ignored because insecure.
writem
macroname- Write macro or string to an open file. Ignored because insecure.
xflag
level- Set the extension level. This is a Heirloom extension and currently ignored.
Numerical expressions
The nr, if, and ie requests accept integer numerical expressions as arguments. These are always evaluated using the C int type; integer overflow works the same way as in the C language. Numbers consist of an arbitrary number of digits ‘0’ to ‘9’ prefixed by an optional sign ‘+’ or ‘-’. Each number may be followed by one optional scaling unit described below Scaling Widths. The following equations hold:
1i = 6v = 6P = 10m = 10n = 72p = 1000M = 240u = 240 254c = 100i = 24000u = 24000 1f = 65536u = 65536
The following binary operators are implemented. Unless otherwise stated, they behave as in the C language:
+
- addition
-
- subtraction
*
- multiplication
/
- division
%
- remainder of division
<
- less than
>
- greater than
==
- equal to
=
- equal to, same effect as
==
(this differs from C) <=
- less than or equal to
>=
- greater than or equal to
<>
- not equal to (corresponds to C
!=
; this one is of limited portability, it is supported by Heirloom roff, but not by groff) &
- logical and (corresponds to C
&&
) :
- logical or (corresponds to C
||
) <?
- minimum (not available in C)
>?
- maximum (not available in C)
There is no concept of precedence; evaluation proceeds from left to right, except when subexpressions are enclosed in parentheses. Inside parentheses, whitespace is ignored.
ESCAPE SEQUENCE REFERENCE
The mandoc(1) roff
parser recognises the
following escape sequences. Note that the roff
language defines more escape sequences not implemented in
mandoc(1). In
mdoc(7) and man(7) documents, using escape sequences is discouraged
except for those described in the
LANGUAGE SYNTAX section above.
A backslash followed by any character not listed here simply prints that character itself.
\<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.
\<space>
The escape sequence backslash-space (‘\ ’) is an unpaddable space-sized non-breaking space character; see Whitespace.
\"
The rest of the input line is treated as Comments.
\%
Hyphenation allowed at this point of the word; ignored by mandoc(1).
\&
Non-printing zero-width character; see Whitespace.
\'
Acute accent special character; use ‘\(aa’ instead.
\(cc
Special Characters with two-letter names, see mandoc_char(7).
\*[name]
Interpolate the string with the name; see Predefined Strings and ds. For short names, there are variants \*c and \*(cc.
\,
Left italic correction (groff extension); ignored by mandoc(1).
\-
Special character “mathematical minus sign”.
\/
Right italic correction (groff extension); ignored by mandoc(1).
\[name]
Special Characters with names of arbitrary length, see mandoc_char(7).
\^
One-twelfth em half-narrow space character, effectively zero-width in mandoc(1).
\`
Grave accent special character; use ‘\(ga’ instead.
\{
Begin conditional input; see if.
\|
One-sixth em narrow space character, effectively zero-width in mandoc(1).
\}
End conditional input; see if.
\~
Paddable non-breaking space character.
\0
Digit width space character.
\A'string'
Anchor definition; ignored by mandoc(1).
\B'string'
Interpolate ‘1’ if string conforms to the syntax of Numerical expressions explained above and ‘0’ otherwise.
\b'string'
Bracket building function; ignored by mandoc(1).
\C'name'
Special Characters with names of arbitrary length.
\c
When encountered at the end of an input text line, the next input text line is considered to continue that line, even if there are request or macro lines in between. No whitespace is inserted.
\D'string'
Draw graphics function; ignored by mandoc(1).
\d
Move down by half a line; ignored by mandoc(1).
\e
Backslash special character.
\F[name]
Switch font family (groff extension); ignored by mandoc(1). For short names, there are variants \Fc and \F(cc.
\f[name]
Switch to the font name, see Text Decoration. For short names, there are variants \fc and \f(cc.
\g[name]
Interpolate the format of a number register; ignored by mandoc(1). For short names, there are variants \gc and \g(cc.
\H'[+|-]number'
Set the height of the current font; ignored by mandoc(1).
\h'[|
]width'
Horizontal motion. If the vertical bar is given, the motion is
relative to the current indentation. Otherwise, it is relative to the
current position. The default scaling unit is m
.
\k[name]
Mark horizontal input place in register; ignored by mandoc(1). For short names, there are variants \kc and \k(cc.
\L'number[c]'
Vertical line drawing function; ignored by mandoc(1).
\l'width[c]'
Draw a horizontal line of width using the glyph c.
\M[name]
Set fill (background) color (groff extension); ignored by mandoc(1). For short names, there are variants \Mc and \M(cc.
\m[name]
Set glyph drawing color (groff extension); ignored by mandoc(1). For short names, there are variants \mc and \m(cc.
\N'number'
Character number on the current font.
\n[name]
Interpolate the number register name. For short names, there are variants \nc and \n(cc.
\o'string'
Overstrike, writing all the characters contained in the string to the same output position. In terminal and HTML output modes, only the last one of the characters is visible.
\p
Break the output line at the end of the current word.
\R'name [+|-]number'
Set number register; ignored by mandoc(1).
\S'number'
Slant output; ignored by mandoc(1).
\s'[+|-]number'
Change point size; ignored by mandoc(1). Alternative forms \s[+|-]n, \s[+|-]'number', \s[[+|-]number], and \s[+|-][number] are also parsed and ignored.
\t
Horizontal tab; ignored by mandoc(1).
\u
Move up by half a line; ignored by mandoc(1).
\V[name]
Interpolate an environment variable; ignored by mandoc(1). For short names, there are variants \Vc and \V(cc.
\v'number'
Vertical motion; ignored by mandoc(1).
\w'string'
Interpolate the width of the string. The mandoc(1) implementation assumes that after expansion of user-defined strings, the string only contains normal characters, no escape sequences, and that each character has a width of 24 basic units.
\X'string'
Output string as device control function; ignored in nroff mode and by mandoc(1).
\x'number'
Extra line space function; ignored by mandoc(1).
\Y[name]
Output a string as a device control function; ignored in nroff mode and by mandoc(1). For short names, there are variants \Yc and \Y(cc.
\Z'string'
Print string with zero width and height; ignored by mandoc(1).
\z
Output the next character without advancing the cursor position.
COMPATIBILITY
The mandoc(1) implementation of the roff
language is intentionally incomplete. Unimplemented features include:
- For security reasons, mandoc(1) never reads or writes external files except via so requests with safe relative paths.
- There is no automatic hyphenation, no adjustment to the right margin, and no centering; the output is always set flush-left.
- Support for setting tabulator positions and tabulator and leader characters is missing, and support for manually changing indentation is limited.
- The ‘u’ scaling unit is the default terminal unit. In traditional troff systems, this unit changes depending on the output media.
- Width measurements are implemented in a crude way and often yield wrong results. Explicit movement requests and escapes are ignored.
- There is no concept of output pages, no support for floats, graphics drawing, and picture inclusion; terminal output is always continuous.
- Requests regarding color, font families, and glyph manipulation are ignored. Font support is very limited. Kerning is not implemented, and no ligatures are produced.
- The "'" macro control character does not suppress output line breaks.
- Diversions are not implemented, and support for traps is very incomplete.
- While recursion is supported, while loops are not.
The special semantics of the nS
number
register is an idiosyncracy of OpenBSD manuals and
not supported by other
mdoc(7) implementations.
SEE ALSO
mandoc(1), eqn(7), man(7), mandoc_char(7), mdoc(7), tbl(7)
Joseph F. Ossanna and Brian W. Kernighan, Troff User's Manual, AT&T Bell Laboratories, Computing Science Technical Report, 54, http://www.kohala.com/start/troff/cstr54.ps, Murray Hill, New Jersey, 1976 and 1992.
Joseph F. Ossanna, Brian W. Kernighan, and Gunnar Ritter, Heirloom Documentation Tools Nroff/Troff User's Manual, http://heirloom.sourceforge.net/doctools/troff.pdf, September 17, 2007.
HISTORY
The RUNOFF typesetting system, whose input forms the basis for
roff
, 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 roff
. Dennis M. Ritchie
rewrote McIlroy's roff
in PDP-11 assembly for
Version 1 AT&T UNIX, Joseph F. Ossanna
improved roff and renamed it nroff for Version 2
AT&T UNIX, then ported nroff to C as troff, which Brian W.
Kernighan released with Version 7 AT&T
UNIX. In 1989, James Clarke re-implemented troff in C++, naming it
groff.
AUTHORS
This roff
reference was written by
Kristaps Dzonsons
<kristaps@bsd.lv> and
Ingo Schwarze
<schwarze@openbsd.org>.