Provided by: mandoc_1.14.3-3_amd64 
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:
\(em Two-letter em dash escape.
\e One-letter backslash escape.
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 indicator or numerical representative may be preceded by
C (constant-width), which is ignored.
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:
\*(Am Two-letter ampersand predefined string.
\*q One-letter double-quote predefined string.
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:
1. the control character ‘.’ or ‘'’ at the beginning of the line,
2. optionally an arbitrary amount of whitespace,
3. the name of the request or the macro, which is one word of arbitrary length, terminated by
whitespace,
4. 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
implement roff compatibility mode at all, it handles this request as an alias for am.
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 implement roff compatibility mode at all, it
handles this request as an alias for ami.
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 implement roff compatibility mode at all, it handles this request as an alias for as.
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
.endmacro
Both 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 a roff request or
roff 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 with roff compatibility mode switched off during macro
execution. This is a groff extension. Since mandoc(1) does not implement roff compatibility
mode at all, it handles this request as an alias for de.
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 of de. The effect is the same as:
.de \*[macrostring] [\*[endstring]]
dei1 macrostring [endstring]
Define a roff macro that will be executed with roff compatibility mode switched off during macro
execution, specifying the macro name indirectly (groff extension). Since mandoc(1) does not
implement roff compatibility mode at all, it handles this request as an alias for dei.
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 implement roff
compatibility mode at all, it handles this request as an alias for ds.
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
prior ie calls) then false is assumed. The syntax of this request is similar to if 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:
B, BI, 3, 4
switches to bold font
I, 2 switches to underlined font
R, CW, 1
switches to normal font
P or no argument
switches back to the previous font
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 to if.
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 .ig
will 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 \{.request
The 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 \} b
will 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
.endmacro
In 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 if
the 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. When ta 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, 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>.