www.LinuxHowtos.org





ROFF

Section: Environments, Tables, and Troff Macros (7)
Index Return to Main Contents

BSD mandoc
 

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 rea-world manuals use small numbers of requests and escape sequences intermixed with their mdoc(7) or man(7) code. To properly format such manuals, the mandoc(1) utility supports a subset of requests and escapes. Even though this manual page lists all requests and escape sequences, it only contains partial information about requests not supported by mandoc(1) and about language features that do not matter for manual pages. For complete manuals, consult the Sx 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 (Qq aq ) 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 fre-form text to be printed; the formatting of the text depends on the respective processing context.  

LANGUAGE SYNTAX

documents may contain only graphable -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 Sx Comments and Sx Special Characters . For a complete listing of escape sequences, consult the Sx ESCAPE SEQUENCE REFERENCE below.  

Comments

Text following an escaped doubl-quote `dq' whether in a request, macro, or text line, is ignored to the end of the line. A request line beginning with a control character and comment escape `.dq' is also ignored. Furthermore, request lines with only a control character and optional trailing whitespace are stripped from input.

Examples: 

.dq This is a comment line.
.dq The next line is ignored:
.
.Sh EXAMPLES dq This is a comment, too.
example text dq 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 ope-parenthesis `(' for tw-character sequences; an ope-bracket `[' for -character sequences (terminated at a clos-bracket `] )' or a single one character sequence.

Examples:

(em
Tw-letter em dash escape.
e
On-letter backslash escape.

See mandoc_char7 for a complete list.  

Font Selection

In mdoc(7) and man(7) documents, fonts are usually selected with macros. The f escape sequence and the ft request can be used to manually change the font, but this is not recommended in mdoc(7) documents. Such manual font changes are overridden by many subsequent macros.

The following fonts are supported:

B
Bold font.
BI
A font that is both bold and italic.
CB
Bold constant width font. Same as B in terminal output.
CI
Italic constant width font. Same as I in terminal output.
CR
Regular constant width font. Same as R in terminal output.
CW
An alias for CR
I
Italic font.
P
Return to the previous font. If a macro caused a font change since the last f eascape sequence or ft request, this returns to the font before the last font change in the macro rather than to the font before the last manual font change.
R
Roman font. This is the default font.
1
An alias for R
2
An alias for I
3
An alias for B
4
An alias for BI

Examples:

fBboldfR
Write in bold, then switch to regular font mode.
fIitalicfP
Write in italic, then return to previous font mode.
f(BIbold italicfP
Write in bold italic, then return to previous font mode.

 

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 space 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 Sx 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 `[-]?[-9]*.[-9]*[:unit:] ' where a decimal must be preceded or followed by at least one digit.

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
min-em (1/100 em)

Using anything other than `m' `n' or `v' is necessarily no-portable across output media. See Sx 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:

.

tw-inch tagged list indentation in mdoc(7)
.HP 2i
tw-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 no-sentence closing delimiters Po `)' `]' `'' `' Pc .

The proper spacing is also intelligently preserved if a sentence ends at the boundary of a macro line.

If an input line happens to end with a period, exclamation or question mark that isn't the end of a sentence, append a zer-width space (`&' )

Examples: 

Do not end sentences mi-line like this.  Instead,
end a sentence like this.
A macro would end like this:
.Xr mandoc 1 .
An abbreviation at the end of an input line needs escaping, e.g.&
like this.
 

REQUEST SYNTAX

A request or macro line consists of:

  1. the control character `.' or `aq' 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 (`dq' ) 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 (`Qq 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 dqconst char *sdq
Group arguments Qq const char *s into one function argument. If unspecified, Qq const , Qq char , and Qq *s would be considered separate arguments.
.[dq-adq ]
Consider Qq Fl a as literal text instead of a flag macro.

 

REQUEST REFERENCE

The mandoc(1) 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 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 compatibility mode at all, it handles this request as an alias for ami
as stringname [string ]
Append to a use-defined string. The syntax of this request is the same as that of ds If a use-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 use-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 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 the innermost while loop.
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 n-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 glyph [string ]
Define or redefine the ASCII character or character escape sequence glyph to be rendered as string which can be empty. Only partially supported in mandoc(1); may interact incorrectly with tr
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 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 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 requests, macros or hig-level macros like man(7) or mdoc(7) macros, whichever applies to the document in question.

Specifying a custom endmacro 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 request or macro, but not as a hig-level macro.

The macro can be invoked later using the syntax

Regarding argument parsing, see Sx 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 N th argument For example, 

.de ZN
fI^$1^fP$2
..
.ZN XtFree .

produces

in the input stream, and thus in the output: XtFree. Each occurrence of $* is replaced with all the arguments, joined together with single space characters. The variant $@ is similar, except that each argument is individually quoted.

Since macros and use-defined strings share a common string table, defining a macro macroname clobbers the use-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 macro that will be executed with compatibility mode switched off during macro execution. This is a groff extension. Since mandoc(1) does not implement 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 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:

dei1 macrostring [endstring ]
Define a macro that will be executed with compatibility mode switched off during macro execution, specifying the macro name indirectly (groff extension). Since mandoc(1) does not implement 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 grof-specific intermediate output format and are unsupported.
di divname
Begin a diversion. Currently unsupported.
do command [argument ... ]
Execute request or macro line with compatibility mode disabled. Currently unsupported.
ds stringname [[dq string ] ]
Define a use-defined string. The stringname and string arguments are spac-separated. If the string begins with a doubl-quote character, that character will not be part of the string. All remaining characters on the input line form the string including whitespace and doubl-quote characters, even trailing ones.

The string can be interpolated into subsequent text by using * Bq 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 use-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 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 [[dq string ] ]
Define a use-defined string that will be expanded with compatibility mode switched off during string expansion. This is a groff extension. Since mandoc(1) does not implement 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
Break the output line and switch to fill mode, which is active by default but can be ended with the nf request. In fill mode, input from subsequent input lines is added to the same output line until the next word no longer fits, at which point the output line is broken. This request is implied by the mdoc(7)
 

macro and by the

man(7) SH SS and EE macros. Ic fkern Ar font minkern Control the use of kerning tables for a font. This is a Heirloom extension and currently ignored. Ic fl Flush output. Currently ignored. Ic flig Ar font string char ... Define ligatures. This is a Heirloom extension and currently ignored. Ic fp Ar position font Op Ar filename Assign font position. Currently ignored. Ic fps Ar mapname ... Mount a font with a special character map. This is a Heirloom extension and currently ignored. Ic fschar Ar font glyphname Op Ar string Define a fon-specific fallback glyph. This is a groff extension and currently unsupported. Ic fspacewidth Ar font Op Ar afmunits Set a fon-specific width for the space character. This is a Heirloom extension and currently ignored. Ic fspecial Ar curfont Op Ar font ... Conditionally define a special font. This is a groff extension and currently ignored. Ic ft Op Ar font Change the font; see Sx Font Selection . The font argument defaults to P Ic ftr Ar newname Op Ar oldname Translate font name. This is a groff extension and currently ignored. Ic fzoom Ar font Op Ar permille Zoom font size. Currently ignored. Ic gcolor Op Ar colorname Set glyph color. This is a groff extension and currently ignored. Ic hc Op Ar char Set the hyphenation character. Currently ignored. Ic hcode Ar char code ... Set hyphenation codes of characters. Currently ignored. Ic hidechar Ar font char ... Hide characters in a font. This is a Heirloom extension and currently ignored. Ic hla Ar language Set hyphenation language. This is a groff extension and currently ignored. Ic hlm Op Ar number Set maximum number of consecutive hyphenated lines. Currently ignored. Ic hpf Ar filename Load hyphenation pattern file. This is a groff extension and currently ignored. Ic hpfa Ar filename Load hyphenation pattern file, appending to the current patterns. This is a groff extension and currently ignored. Ic hpfcode Ar code code ... Define mapping values for character codes in hyphenation patterns. This is a groff extension and currently ignored. Ic hw Ar word ... Specify hyphenation points in words. Currently ignored. Ic hy Op Ar mode Set automatic hyphenation mode. Currently ignored. Ic hylang Ar language Set hyphenation language. This is a Heirloom extension and currently ignored. Ic hylen Ar nchar Minimum word length for hyphenation. This is a Heirloom extension and currently ignored. Ic hym Op Ar length Set hyphenation margin. This is a groff extension and currently ignored. Ic hypp Ar penalty ... Define hyphenation penalties. This is a Heirloom extension and currently ignored. Ic hys Op Ar length Set hyphenation space. This is a groff extension and currently ignored. Ic ie Ar 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 Ic if Ar 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 a conditional is false, its children are not processed, but are syntactically interpreted to preserve the integrity of the input document. Thus,

will discard the `.ig' which may lead to interesting results, but

will continue to syntactically interpret to the block close of the final conditional. Su-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 closin-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

The scope of a conditional is always parsed, but only executed if the conditional evaluates to true.

Note that the `}' is converted into a zer-width escape sequence if not passed as a standalone macro `.}' For example,

will result in `}' being considered an argument of the `- ' macro. Ic ig Op Ar 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

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. Ic in Op Oo Cm + Ns | Ns Cm- Oc Ns Ar width Change indentation. See man(7). Ignored in mdoc(7). Ic index Ar register stringname substring Find a substring in a string. This is a Heirloom extension and currently unsupported. Ic it Ar 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 Sx Scaling Widths are ignored. Ic itc Ar expression macro Set an input line trap, not counting lines ending with c. Currently unsupported. Ic IX Ar class keystring To support the generation of a table of contents, pod2man(1) emits this use-defined macro, usually without defining it. To avoid reporting large numbers of spurious errors, mandoc(1) ignores it. Ic kern Op Cm 1 | 0 Switch kerning on or off. Currently ignored. Ic kernafter Ar font char ... afmunits ... Increase kerning after some characters. This is a Heirloom extension and currently ignored. Ic kernbefore Ar font char ... afmunits ... Increase kerning before some characters. This is a Heirloom extension and currently ignored. Ic kernpair Ar font char ... font char ... afmunits Add a kerning pair to the kerning table. This is a Heirloom extension and currently ignored. Ic lc Op Ar glyph Define a leader repetition character. Currently unsupported. Ic lc_ctype Ar localename Set the LC_CTYPE locale. This is a Heirloom extension and currently unsupported. Ic lds Ar macroname string Define a local string. This is a Heirloom extension and currently unsupported. Ic length Ar register string Count the number of input characters in a string. Currently unsupported. Ic letadj Ar lspmin lshmin letss lspmax lshmax Dynamic letter spacing and reshaping. This is a Heirloom extension and currently ignored. Ic lf Ar lineno Op Ar filename Change the line number for error messages. Ignored because insecure. Ic lg Op Cm 1 | 0 Switch the ligature mechanism on or off. Currently ignored. Ic lhang Ar font char ... afmunits Hang characters at left margin. This is a Heirloom extension and currently ignored. Ic linetabs Op Cm 1 | 0 Enable or disable lin-tabs mode. This is a groff extension and currently unsupported. Ic ll Op Oo Cm + Ns | Ns Cm- Oc Ns Ar 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. Ic lnr Ar register Oo Cm + Ns | Ns Cm- Oc Ns Ar value Op Ar increment Set local number register. This is a Heirloom extension and currently unsupported. Ic lnrf Ar register Oo Cm + Ns | Ns Cm- Oc Ns Ar value Op Ar increment Set local floatin-point register. This is a Heirloom extension and currently unsupported. Ic lpfx Ar string Set a line prefix. This is a Heirloom extension and currently unsupported. Ic ls Op Ar factor Set line spacing. It takes one integer argument specifying the vertical distance of subsequent output text lines measured in v units. Currently ignored. Ic lsm Ar macroname Set a leading spaces trap. This is a groff extension and currently unsupported. Ic lt Op Oo Cm + Ns | Ns Cm- Oc Ns Ar width Set title line length. Currently ignored. Ic mc Ar glyph Op Ar dist Print margin character in the right margin. The dist is currently ignored; instead, 1n is used. Ic mediasize Ar media Set the device media size. This is a Heirloom extension and currently ignored. Ic minss Ar width Set minimum word space. This is a Heirloom extension and currently ignored. Ic mk Op Ar register Mark vertical position. Currently ignored. Ic mso Ar filename Load a macro file using the search path. Ignored because insecure. Ic na Disable adjusting without changing the adjustment mode. Currently ignored. Ic ne Op Ar height Declare the need for the specified minimum vertical space before the next trap or the bottom of the page. Currently ignored. Ic nf Break the output line and switch to n-fill mode. Subsequent input lines are kept together on the same output line even when exceeding the right margin, and line breaks in subsequent input cause output line breaks. This request is implied by the mdoc(7) and macros and by the man(7) EX macro. The fi request switches back to the default fill mode. Ic nh Turn off automatic hyphenation mode. Currently ignored. Ic nhychar Ar char ... Define hyphenatio-inhibiting characters. This is a Heirloom extension and currently ignored. Ic nm Op Ar start Op Ar inc Op Ar space Op Ar indent Print line numbers. Currently unsupported. Ic nn Op Ar number Temporarily turn off line numbering. Currently unsupported. Ic nop Ar body Execute the rest of the input line as a request, macro, or text line, skipping the nop request and any space characters immediately following it. This is mostly used to indent text lines inside macro definitions. Ic nr Ar register Oo Cm + Ns | Ns Cm- Oc Ns Ar expression Op Ar stepsize 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 Sx Numerical expressions below. If it is prefixed by a sign, the register will be incremented or decremented instead of assigned to.

The stepsize is used by the n+ aut-increment feature. It remains unchanged when omitted while changing an existing register, and it defaults to 0 when defining a new register.

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
 

macro will reset this register.

Xo nrf register [+ | - expression ] [increment ] Define or change a floatin-point register. This is a Heirloom extension and currently unsupported. Ic nroff Force nroff mode. This is a groff extension and currently ignored. Ic ns Turn on n-space mode. Currently ignored. Ic nx Op Ar filename Abort processing of the current input file and process another one. Ignored because insecure. Ic open Ar stream file Open a file for writing. Ignored because insecure. Ic opena Ar stream file Open a file for appending. Ignored because insecure. Ic os Output saved vertical space. Currently ignored. Ic output Ar string Output directly to intermediate output. Not supported. Ic padj Op Cm 1 | 0 Globally control paragrap-a-once adjustment. This is a Heirloom extension and currently ignored. Ic papersize Ar media Set the paper size. This is a Heirloom extension and currently ignored. Ic pc Op Ar char Change the page number character. Currently ignored. Ic pev Print environments. This is a groff extension and currently ignored. Ic pi Ar command Pipe output to a shell command. Ignored because insecure. Ic PI Lo-level request used by BP This is a Heirloom extension and currently unsupported. Ic pl Op Oo Cm + Ns | Ns Cm- Oc Ns Ar height Change page length. Currently ignored. Ic pm Print names and sizes of macros, strings, and diversions to standard error output. Currently ignored. Ic pn Oo Cm + Ns | Ns Cm- Oc Ns Ar number Change the page number of the next page. Currently ignored. Ic pnr Print all number registers on standard error output. Currently ignored. Ic po Op Oo Cm + Ns | Ns Cm- Oc Ns Ar 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 Sx Scaling Widths and the default scaling unit is m Ic ps Op Oo Cm + Ns | Ns Cm- Oc Ns size Change point size. Currently ignored. Ic psbb Ar filename Retrieve the bounding box of a PostScript file. Currently unsupported. Ic pshape Ar indent length ... Set a special shape for the current paragraph. This is a Heirloom extension and currently unsupported. Ic pso Ar command Include output of a shell command. Ignored because insecure. Ic ptr Print the names and positions of all traps on standard error output. This is a groff extension and currently ignored. Ic pvs Op Oo Cm + Ns | Ns Cm- Oc Ns Ar height Change pos-vertical spacing. This is a groff extension and currently ignored. Ic rchar Ar glyph ... Remove glyph definitions. Currently unsupported. Ic rd Op Ar prompt Op Ar argument ... Read from standard input. Currently ignored. Ic recursionlimit Ar maxrec maxtail Set the maximum stack depth for recursive macros. This is a Heirloom extension and currently ignored. Ic return Op Ar twice Exit the presently executed macro and return to the caller. The argument is currently ignored. Ic rfschar Ar font glyph ... Remove fon-specific fallback glyph definitions. Currently unsupported. Ic rhang Ar font char ... afmunits Hang characters at right margin. This is a Heirloom extension and currently ignored. Ic rj Op Ar 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. Ic rm Ar macroname Remove a request, macro or string. Ic rn Ar oldname newname Rename a request, macro, diversion, or string. In mandoc(1), use-defined macros, mdoc(7) and man(7) macros, and use-defined strings can be renamed, but renaming of predefined strings and of requests is not supported, and diversions are not implemented at all. Ic rnn Ar oldname newname Rename a number register. Currently unsupported. Ic rr Ar register Remove a register. Ic rs End n-space mode. Currently ignored. Ic rt Op Ar dist Return to marked vertical position. Currently ignored. Ic schar Ar glyph Op Ar string Define global fallback glyph. This is a groff extension and currently unsupported. Ic sentchar Ar char ... Define sentenc-ending characters. This is a Heirloom extension and currently ignored. Ic shc Op Ar glyph Change the soft hyphen character. Currently ignored. Ic shift Op Ar number Shift macro arguments number times, by default once: $i becomes what $i+number was. Also decrement n(.$ by number Ic sizes Ar size ... Define permissible point sizes. This is a groff extension and currently ignored. Ic so Ar 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 Qq ../ and Qq /.. .

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. Ic sp Op Ar height Break the output line and emit vertical space. The argument follows the syntax of Sx Scaling Widths and defaults to one blank line (1v ) Ic spacewidth Op Cm 1 | 0 Set the space width from the font metrics file. This is a Heirloom extension and currently ignored. Ic special Op Ar font ... Define a special font. This is a groff extension and currently ignored. Ic spreadwarn Op Ar width Warn about wide spacing between words. Currently ignored. Ic ss Ar wordspace Op Ar sentencespace Set space character size. Currently ignored. Ic sty Ar position style Associate style with a font position. This is a groff extension and currently ignored. Ic substring Ar stringname startpos Op Ar endpos Replace a use-defined string with a substring. Currently unsupported. Ic sv Op Ar height Save vertical space. Currently ignored. Ic sy Ar command Execute shell command. Ignored because insecure. Ic T& R-start a table layout, retaining the options of the prior table invocation. See TS Ic ta Op Ar width ... Op Cm T Ar width ... Set tab stops. Each width argument follows the syntax of Sx 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. Ic tc Op Ar glyph Change tab repetition character. Currently unsupported. Ic TE End a table context. See TS Ic ti Oo Cm + Ns | Ns Cm- Oc Ns Ar 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 Sx Scaling Widths and the default scaling unit is m Ic tkf Ar font minps width1 maxps width2 Enable track kerning for a font. Currently ignored. Ic tl No Ap Ar left Ap Ar center Ap Ar right Ap Print a title line. Currently unsupported. Ic tm Ar string Print to standard error output. Currently ignored. Ic tm1 Ar string Print to standard error output, allowing leading blanks. This is a groff extension and currently ignored. Ic tmc Ar string Print to standard error output without a trailing newline. This is a groff extension and currently ignored. Ic tr Ar 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. Ic track Ar font minps width1 maxps width2 Static letter space tracking. This is a Heirloom extension and currently ignored. Ic transchar Ar char ... Define transparent characters for sentenc-ending. This is a Heirloom extension and currently ignored. Ic trf Ar filename Output the contents of a file, disallowing invalid characters. This is a groff extension and ignored because insecure. Ic trimat Ar left top width height Set the TrimBox page parameter for PDF generation. This is a Heirloom extension and currently ignored. Ic trin Ar glyph glyph ... Output character translation, ignored by asciify Currently unsupported. Ic trnt Ar glyph glyph ... Output character translation, ignored by !. Currently unsupported. Ic troff Force troff mode. This is a groff extension and currently ignored. Ic TS Begin a table, which formats input in aligned rows and columns. See tbl(7) for a description of the tbl language. Ic uf Ar font Globally set the underline font. Currently ignored. Ic ul Op Ar N Underline next N input lines. Currently ignored. Ic unformat Ar divname Unformat spaces and tabs in a diversion. Currently unsupported. Ic unwatch Ar macroname Disable notification for string or macro. This is a Heirloom extension and currently ignored. Ic unwatchn Ar register Disable notification for register. This is a Heirloom extension and currently ignored. Ic vpt Op Cm 1 | 0 Enable or disable vertical position traps. This is a groff extension and currently ignored. Ic vs Op Oo Cm + Ns | Ns Cm- Oc Ns Ar height Change vertical spacing. Currently ignored. Ic warn Ar flags Set warning level. Currently ignored. Ic warnscale Ar si Set the scaling indicator used in warnings. This is a groff extension and currently ignored. Ic watch Ar macroname Notify on change of string or macro. This is a Heirloom extension and currently ignored. Ic watchlength Ar maxlength On change, report the contents of macros and strings up to the specified length. This is a Heirloom extension and currently ignored. Ic watchn Ar register Notify on change of register. This is a Heirloom extension and currently ignored. Ic wh Ar dist Op Ar macroname Set a page location trap. Currently unsupported. Ic while Ar condition body Repeated execution while a condition is true, with syntax similar to if Currently implemented with two restrictions: cannot nest, and each loop must start and end in the same scope. Ic write Oo dq Oc Ns Ar string Write to an open file. Ignored because insecure. Ic writec Oo dq Oc Ns Ar string Write to an open file without appending a newline. Ignored because insecure. Ic writem Ar macroname Write macro or string to an open file. Ignored because insecure. Ic xflag Ar 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 Vt 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 Sx 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) parser recognises the following escape sequences. In mdoc(7) and man(7) documents, using escape sequences is discouraged except for those described in the Sx 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 backslas-space (` ' ) is an unpaddable spac-sized no-breaking space character; see Sx Whitespace and mandoc_char7.
!
Embed text up to and including the end of the input line into the current diversion or into intermediate output without interpreting requests, macros, and escapes. Currently unsupported.
dq
The rest of the input line is treated as Sx Comments .
#
Line continuation with comment. Discard the rest of the physical input line and 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. This is a groff extension.
$ arg
Macro argument expansion, see de
%
Hyphenation allowed at this point of the word; ignored by mandoc(1).
&
No-printing zer-width character, often used for various kinds of escaping; see Sx Whitespace , mandoc_char7, and the ``MACRO SYNTAX'' and ``Delimiters'' sections in mdoc(7).
aq
Acute accent special character; use (aa instead.
( cc
Sx Special Characters with tw-letter names, see mandoc_char7.
)
Zer-width space transparent to en-o-sentence detection; ignored by mandoc(1).
*[ name ]
Interpolate the string with the name For short names, there are variants * c and *( cc

One string is predefined on the language level: *(.T expands to the name of the output device, for example ascii, utf8, ps, pdf, html, or markdown.

Macro sets traditionally predefine additional strings which are not portable and differ across implementations. Those supported by mandoc(1) are listed in mandoc_char7.

Strings can be defined, changed, and deleted with the ds as and rm requests.

,
Left italic correction (groff extension); ignored by mandoc(1).
-
Special character ``mathematical minus sign'' see mandoc_char7 for details.
/
Right italic correction (groff extension); ignored by mandoc(1).
:
Breaking the line is allowed at this point of the word without inserting a hyphen.
?
Embed the text up to the next ? into the current diversion without interpreting requests, macros, and escapes. This is a groff extension and currently unsupported.
[ name ]
Sx Special Characters with names of arbitrary length, see mandoc_char7.
^
On-twelfth em hal-narrow space character, effectively zer-width in mandoc(1).
_
Underline special character; use (ul instead.
`
Grave accent special character; use (ga instead.
{
Begin conditional input; see if
ba
On-sixth em narrow space character, effectively zer-width in mandoc(1).
}
End conditional input; see if
~
Paddable no-breaking space character.
0
Digit width space character.
Aaq string aq
Anchor definition; ignored by mandoc(1).
a
Leader character; ignored by mandoc(1).
Baq string aq
Interpolate `1' if string conforms to the syntax of Sx Numerical expressions explained above or `0' otherwise.
baq string aq
Bracket building function; ignored by mandoc(1).
Caq name aq
Sx 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.
Daq string aq
Draw graphics function; ignored by mandoc(1).
d
Move down by half a line; ignored by mandoc(1).
E
Escape character intended to not be interpreted in copy mode. In mandoc(1), it currently does the same as itself.
e
Backslash special character.
F[ name ]
Switch font family (groff extension); ignored by mandoc(1). For short names, there are variants F c and F( cc
f[ name ]
Switch to the font name see Sx Font Selection . For short names, there are variants f c and f( cc An empty name f[] defaults to fP
g[ name ]
Interpolate the format of a number register; ignored by mandoc(1). For short names, there are variants g c and g( cc
Haq [+- number aq ]
Set the height of the current font; ignored by mandoc(1).
haq [| width aq ]
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 k c and k( cc
Laq number [c aq ]
Vertical line drawing function; ignored by mandoc(1).
laq width [c aq ]
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 M c and M( cc
m[ name ]
Set glyph drawing color (groff extension); ignored by mandoc(1). For short names, there are variants m c and m( cc
Naq number aq
Character number on the current font.
n [+- [ name ] ]
Interpolate the number register name For short names, there are variants n c and n( cc If the optional sign is specified, the register is first incremented or decremented by the stepsize that was specified in the relevant nr request, and the changed value is interpolated.
O digit , O[5 arguments ]
Suppress output. This is a groff extension and currently unsupported. With an argument of 1 , 2 , 3 or 4 it is ignored.
oaq string aq
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.
Raq name [+- number aq ]
Set number register; ignored by mandoc(1).
r
Move up by one line; ignored by mandoc(1).
Saq number aq
Slant output; ignored by mandoc(1).
saq [+- number aq ]
Change point size; ignored by mandoc(1). Alternative forms s [+- n ] s [+- aq number aq ] 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 V c and V( cc
vaq number aq
Vertical motion; ignored by mandoc(1).
waq string aq
Interpolate the width of the string The mandoc(1) implementation assumes that after expansion of use-defined strings, the string only contains normal characters, no escape sequences, and that each character has a width of 24 basic units.
Xaq string aq
Output string as device control function; ignored in nroff mode and by mandoc(1).
xaq number aq
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 Y c and Y( cc
Zaq string aq
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 language is incomplete. Major 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 very limited support for centering; the output is always set flus-left.
Support for setting 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. Support for explicit movement requests and escapes is limited.
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, font sizes,
and glyph manipulation are ignored. Font support is very limited. Kerning is not implemented, and no ligatures are produced.
The
Qq aq macro control character does not suppress output line breaks.
Diversions and environments are not implemented,
and support for traps is very incomplete.
Use of macros is not supported inside
tbl(7) code.

The special semantics of the nS number register is an idiosyncrasy of Ox manuals and not supported by other mdoc(7) implementations.  

SEE ALSO

mandoc(1), eqn(7), man(7), mandoc_char7, mdoc(7), tbl(7)
Joseph F. Ossanna Brian W. Kernighan Troff User's Manual Computing Science Technical Report 54 1976 and 1992
Joseph F. Ossanna Brian W. Kernighan Gunnar Ritter Heirloom Documentation Tools Nroff/Troff User's Manual September 17, 2007
 

HISTORY

The RUNOFF typesetting system, whose input forms the basis for , 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 . Dennis M. Ritchie rewrote McIlroy's in PD-11 assembly for AT&T System v1 , Joseph F. Ossanna improved roff and renamed it nroff for AT&T System v2 , then ported nroff to C as troff, which Brian W. Kernighan released with AT&T System v7 . In 1989, James Clark r-implemented troff in C++, naming it groff.  

AUTHORS

An -nosplit This reference was written by An Kristaps Dzonsons Aq Mt kristaps@bsd.lv and An Ingo Schwarze Aq Mt schwarze@openbsd.org .

 

Index

NAME
DESCRIPTION
LANGUAGE SYNTAX
Comments
Special Characters
Font Selection
Whitespace
Scaling Widths
Sentence Spacing
REQUEST SYNTAX
MACRO SYNTAX
REQUEST REFERENCE
macro and by the
macro will reset this register.
Numerical expressions
ESCAPE SEQUENCE REFERENCE
COMPATIBILITY
SEE ALSO
HISTORY
AUTHORS