GROFF_MDOC(7) MidnightBSD Miscellaneous Information Manual GROFF_MDOC(7)


groff_mdoc — reference for groff’s mdoc implementation


groff −mdoc file ...


A complete reference for writing UNIX manual pages with the −mdoc macro package; a content-based and domain-based formatting package for GNU troff(1). Its predecessor, the −man(7) package, addressed page layout leaving the manipulation of fonts and other typesetting details to the individual author. In −mdoc, page layout macros make up the page structure domain which consists of macros for titles, section headers, displays and lists − essentially items which affect the physical position of text on a formatted page. In addition to the page structure domain, there are two more domains, the manual domain and the general text domain. The general text domain is defined as macros which perform tasks such as quoting or emphasizing pieces of text. The manual domain is defined as macros that are a subset of the day to day informal language used to describe commands, routines and related UNIX files. Macros in the manual domain handle command names, command line arguments and options, function names, function parameters, pathnames, variables, cross references to other manual pages, and so on. These domain items have value for both the author and the future user of the manual page. Hopefully, the consistency gained across the manual set will provide easier translation to future documentation tools.

Throughout the UNIX manual pages, a manual entry is simply referred to as a man page, regardless of actual length and without sexist intention.


The material presented in the remainder of this document is outlined as follows:



Macro Usage
Passing Space Characters in an Argument
Trailing Blank Space Characters
Escaping Special Characters
Other Possible Pitfalls









What’s in a Name...
General Syntax



Author Name
Configuration Declarations (Section Four Only)
Command Modifiers
Defined Variables
Environment Variables
Function Declarations
Function Types
Functions (Library Routines)
Function Arguments
Return Values
Exit Status
Interactive Commands
Library Names
Variable Types
Manual Page Cross References



AT&T Macro
BSD Macro
NetBSD Macro
FreeBSD Macro
MidnightBSD Macro
DragonFly Macro
OpenBSD Macro
BSD/OS Macro
UNIX Macro
Emphasis Macro
Font Mode
Enclosure and Quoting Macros
No-Op or Normal Text Macro
No-Space Macro
Section Cross References
Mathematical Symbols
References and Citations
Trade Names (or Acronyms and Type Names)
Extended Arguments




Section Headers
Subsection Headers
Paragraphs and Line Spacing
Examples and Displays
Lists and Columns
















The −mdoc package attempts to simplify the process of writing a man page. Theoretically, one should not have to learn the tricky details of GNU troff(1) to use −mdoc; however, there are a few limitations which are unavoidable and best gotten out of the way. And, too, be forewarned, this package is not fast.

Macro Usage
As in GNU troff(1), a macro is called by placing a ‘.’ (dot character) at the beginning of a line followed by the two-character (or three-character) name for the macro. There can be space or tab characters between the dot and the macro name. Arguments may follow the macro separated by spaces (but no tabs). It is the dot character at the beginning of the line which causes GNU troff(1) to interpret the next two (or more) characters as a macro name. A single starting dot followed by nothing is ignored. To place a ‘.’ (dot character) at the beginning of an input line in some context other than a macro invocation, precede the ‘.’ (dot) with the ‘\&’ escape sequence which translates literally to a zero-width space, and is never displayed in the output.

In general, GNU troff(1) macros accept an unlimited number of arguments (contrary to other versions of troff which can’t handle more than nine arguments). In limited cases, arguments may be continued or extended on the next line (See Extended Arguments below). Almost all macros handle quoted arguments (see Passing Space Characters in an Argument below).

Most of the −mdoc general text domain and manual domain macros are special in that their argument lists are parsed for callable macro names. This means an argument on the argument list which matches a general text or manual domain macro name (and which is defined to be callable) will be executed or called when it is processed. In this case the argument, although the name of a macro, is not preceded by a ‘.’ (dot). This makes it possible to nest macros; for example the option macro, ‘.Op’, may call the flag and argument macros, ‘Fl’ and ‘Ar’, to specify an optional flag with an argument:

[−s bytes]

is produced by ‘.Op Fl s Ar bytes’

To prevent a string from being interpreted as a macro name, precede the string with the escape sequence ‘\&’:

[Fl s Ar bytes]

is produced by ‘.Op \&Fl s \&Ar bytes’

Here the strings ‘Fl’ and ‘Ar’ are not interpreted as macros. Macros whose argument lists are parsed for callable arguments are referred to as parsed and macros which may be called from an argument list are referred to as callable throughout this document. This is a technical faux pas as almost all of the macros in −mdoc are parsed, but as it was cumbersome to constantly refer to macros as being callable and being able to call other macros, the term parsed has been used.

In the following, we call an −mdoc macro which starts a line (with a leading dot) a command if this distinction is necessary.

Passing Space Characters in an Argument
Sometimes it is desirable to give as an argument a string containing one or more blank space characters, say, to specify arguments to commands which expect particular arrangement of items in the argument list. Additionally, it makes −mdoc working faster. For example, the function command ‘.Fn’ expects the first argument to be the name of a function and any remaining arguments to be function parameters. As ANSI C stipulates the declaration of function parameters in the parenthesized parameter list, each parameter is guaranteed to be at minimum a two word string. For example, int foo.

There are two possible ways to pass an argument which contains an embedded space. One way of passing a string containing blank spaces is to use the hard or unpaddable space character ‘\ ’, that is, a blank space preceded by the escape character ‘\’. This method may be used with any macro but has the side effect of interfering with the adjustment of text over the length of a line. Troff sees the hard space as if it were any other printable character and cannot split the string into blank or newline separated pieces as one would expect. This method is useful for strings which are not expected to overlap a line boundary. An alternative is to use ‘\~’, a paddable (i.e. stretchable), unbreakable space (this is a GNU troff(1) extension). The second method is to enclose the string with double quotes.

For example:

fetch(char *str)

is created by ‘.Fn fetch char\ *str’

fetch(char *str)

can also be created by ‘.Fn fetch "char *str"’

If the ‘\’ before the space in the first example or double quotes in the second example were omitted, ‘.Fn’ would see three arguments, and the result would be:

fetch(char, *str)

Trailing Blank Space Characters
Troff can be confused by blank space characters at the end of a line. It is a wise preventive measure to globally remove all blank spaces from 〈

blank-space 〉〈
end-of-line 〉 character sequences. Should the need arise to use a blank character at the end of a line, it may be forced with an unpaddable space and the ‘\&’ escape character. For example, ‘string\ \&’.

Escaping Special Characters
Special characters like the newline character ‘\n’ are handled by replacing the ‘\’ with ‘\e’ (e.g. ‘\en’) to preserve the backslash.

Other Possible Pitfalls
A warning is emitted when an empty input line is found outside of displays (see below). Use ‘.sp’ instead. (Well, it is even better to use −mdoc macros to avoid the usage of low-level commands.)

Leading spaces will cause a break and are output directly. Avoid this behaviour if possible. Similarly, do not use more than one space character between words in an ordinary text line; contrary to other text formatters, they are not replaced with a single space.

You can’t pass ‘"’ directly as an argument. Use ‘\*[q]’ (or ‘\*q’) instead.

By default, troff(1) inserts two space characters after a punctuation mark closing a sentence; characters like ‘)’ or ‘’’ are treated transparently, not influencing the sentence-ending behaviour. To change this, insert ‘\&’ before or after the dot:

.Ql .
.Ql \&.
.No test .
.No test.


The ‘’. character

The ‘.’ character.

test. test

test. test

As can be seen in the first and third line, −mdoc handles punctuation characters specially in macro arguments. This will be explained in section General Syntax below. In the same way, you have to protect trailing full stops of abbreviations with a trailing zero-width space: ‘e.g.\&’.

A comment in the source file of a man page can be either started with ‘.\"’ on a single line, ‘\"’ after some input, or ‘\#’ anywhere (the latter is a GNU troff(1) extension); the rest of such a line is ignored.


The body of a man page is easily constructed from a basic template:

.\" The following commands are required for all man pages.
.Dd Month day, year
.Os [OPERATING_SYSTEM] [version/release]
.Dt DOCUMENT_TITLE [section number] [architecture/volume]
.Nm name
.Nd one line description of name
.\" This next command is for sections 2 and 3 only.
.\" The following commands should be uncommented and
.\" used where appropriate.
.\" This next command is for sections 2, 3 and 9 function
.\" return values only.
.\" This next command is for sections 1, 6, 7 and 8 only.
.\" .Sh FILES
.\" This next command is for sections 1, 6, 7, 8 and 9 only
.\" (command return values (to shell) and
.\" fprintf/stderr type diagnostics).
.\" This next command is for sections 2, 3 and 9 error
.\" and signal handling only.
.\" .Sh ERRORS
.\" .Sh SEE ALSO
.\" .Sh BUGS

The first items in the template are the commands ‘.Dd’, ‘.Os’, and ‘.Dt’; the document date, the operating system the man page or subject source is developed or modified for, and the man page title (in upper case) along with the section of the manual the page belongs in. These commands identify the page and are discussed below in TITLE MACROS.

The remaining items in the template are section headers (.Sh); of which NAME, SYNOPSIS, and DESCRIPTION are mandatory. The headers are discussed in PAGE STRUCTURE DOMAIN, after presentation of MANUAL DOMAIN. Several content macros are used to demonstrate page layout macros; reading about content macros before page layout macros is recommended.


In the description of all macros below, optional arguments are put into brackets. An ellipsis (‘...’) represents zero or more additional arguments. Alternative values for a parameter are separated with ‘|’. If there are alternative values for a mandatory parameter, braces are used (together with ‘|’) to enclose the value set. Meta-variables are specified within angles.


〈foo〉 {bar1 | bar2} [−test1 [−test2 | −test3]] ...

Except stated explicitly, all macros are parsed and callable.

Note that a macro takes effect up to the next nested macro. For example, ‘.Ic foo Aq bar’ doesn’t produce ‘foo <bar>’ but ‘foo 〈bar〉’. Consequently, a warning message is emitted for most commands if the first argument is a macro itself since it cancels the effect of the calling command completely. Another consequence is that quoting macros never insert literal quotes; ‘foo <bar>’ has been produced by ‘.Ic "foo <bar>"’.

Most macros have a default width value which can be used to specify a label width (−width) or offset (−offset) for the ‘.Bl’ and ‘.Bd’ macros. It is recommended not to use this rather obscure feature to avoid dependencies on local modifications of the −mdoc package.


The title macros are part of the page structure domain but are presented first and separately for someone who wishes to start writing a man page yesterday. Three header macros designate the document title or manual page title, the operating system, and the date of authorship. These macros are called once at the very beginning of the document and are used to construct headers and footers only.

[〈document title〉] [〈section number〉] [〈volume〉]

The document title is the subject of the man page and must be in CAPITALS due to troff limitations. If omitted, ‘UNTITLED’ is used. The section number may be a number in the range 1, ..., 9 or ‘unass’, ‘draft’, or ‘paper’. If it is specified, and no volume name is given, a default volume name is used.

Under MidnightBSD 0.3, the following sections are defined:


MidnightBSD General Commands Manual


MidnightBSD System Calls Manual


MidnightBSD Library Functions Manual


MidnightBSD Kernel Interfaces Manual


MidnightBSD File Formats Manual


MidnightBSD Games Manual


MidnightBSD Miscellaneous Information Manual


MidnightBSD System Manager’s Manual


MidnightBSD Kernel Developer’s Manual

A volume name may be arbitrary or one of the following:


User’s Supplementary Documents


Programmer’s Supplementary Documents


Ancestral Manual Documents


System Manager’s Manual


User’s Reference Manual


Programmer’s Manual


Kernel Manual


Manual Master Index


Local Manual


Contributed Software Manual

For compatibility, ‘MMI’ can be used for ‘IND’, and ‘LOC’ for ‘LOCAL’. Values from the previous table will specify a new volume name. If the third parameter is a keyword designating a computer architecture, its value is prepended to the default volume name as specified by the second parameter. By default, the following architecture keywords are defined:

alpha, acorn26, acorn32, algor, amd64, amiga, arc, arm26, arm32, atari, bebox, cats, cesfic, cobalt, dreamcast, evbarm, evbmips, evbppc, evbsh3, hp300, hp700, hpcmips, i386, luna68k, m68k, mac68k, macppc, mips, mmeye, mvme68k, mvmeppc, netwinder, news68k, newsmips, next68k, ofppc, pc532, pmax, pmppc, powerpc, prep, sandpoint, sgimips, sh3, shark, sparc, sparc64, sun3, tahoe, vax, x68k, x86_64

If the section number is neither a numeric expression in the range 1 to 9 nor one of the above described keywords, the third parameter is used verbatim as the volume name.

In the following examples, the left (which is identical to the right) and the middle part of the manual page header strings are shown. Note how ‘\&’ prevents the digit 7 from being a valid numeric expression.

.Dt FOO 7

‘FOO(7)’ ‘MidnightBSD Miscellaneous Information Manual’

.Dt FOO 7 bar

‘FOO(7)’ ‘MidnightBSD Miscellaneous Information Manual’

.Dt FOO \&7 bar

‘FOO(7)’ ‘bar’

.Dt FOO 2 i386

‘FOO(2)’ ‘MidnightBSD/i386 System Calls Manual’

.Dt FOO "" bar

‘FOO’ ‘bar’

Local, OS-specific additions might be found in the file mdoc.local; look for strings named ‘volume-ds-XXX’ (for the former type) and ‘volume-as-XXX’ (for the latter type); ‘XXX’ then denotes the keyword to be used with the ‘.Dt’ macro.

This macro is neither callable nor parsed.

[〈operating system〉] [〈release〉]

If the first parameter is empty, the default ‘MidnightBSD 0.3’ is used. This may be overridden in the local configuration file, mdoc.local. In general, the name of the operating system should be the common acronym, e.g. BSD or ATT. The release should be the standard release nomenclature for the system specified. In the following table, the possible second arguments for some predefined operating systems are listed. Similar to ‘.Dt’, local additions might be defined in mdoc.local; look for strings named ‘operating-system-XXX-YYY’, where ‘XXX’ is the acronym for the operating system and ‘YYY’ the release ID.


7th, 7, III, 3, V, V.2, V.3, V.4


3, 4, 4.1, 4.2, 4.3, 4.3t, 4.3T, 4.3r, 4.3R, 4.4


0.8, 0.8a, 0.9, 0.9a, 1.0, 1.0a, 1.1, 1.2, 1.2a, 1.2b, 1.2c, 1.2d, 1.2e, 1.3, 1.3a, 1.4, 1.4.1, 1.4.2, 1.4.3, 1.5, 1.5.1, 1.5.2, 1.5.3, 1.6, 1.6.1, 1.6.2, 2.0, 2.0.1, 2.0.2, 2.1, 3.0


1.0, 1.1, 1.1.5,, 2.0, 2.0.5, 2.1, 2.1.5, 2.1.6, 2.1.7, 2.2, 2.2.1, 2.2.2, 2.2.5, 2.2.6, 2.2.7, 2.2.8, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 4.0, 4.1, 4.1.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.6.2, 4.7, 4.8, 4.9, 4.10, 4.11, 5.0, 5.1, 5.2, 5.2.1, 5.3, 5.4, 5.5, 6.0, 6.1, 6.2




1.0, 1.1, 1.2, 1.3, 1.4, 1.5


8.0.0, 8.1.0, 8.2.0, 8.3.0

For ATT, an unknown second parameter will be replaced with the string UNIX; for the other predefined acronyms it will be ignored and a warning message emitted. Unrecognized arguments are displayed as given in the page footer. For instance, a typical footer might be:

.Os BSD 4.3

giving ‘4.3 Berkeley Distribution’, or for a locally produced set

.Os CS Department

which will produce ‘CS Department’.

If the ‘.Os’ macro is not present, the bottom left corner of the manual page will be ugly.

This macro is neither callable nor parsed.

.Dd [
〈month〉 〈day〉, 〈year〉]

If ‘Dd’ has no arguments, ‘Epoch’ is used for the date string. If it has exactly three arguments, they are concatenated, separated with unbreakable space:

.Dd January 25, 2001

The month’s name shall not be abbreviated.

With any other number of arguments, the current date is used, ignoring the parameters.

This macro is neither callable nor parsed.


What’s in a Name...
The manual domain macro names are derived from the day to day informal language used to describe commands, subroutines and related files. Slightly different variations of this language are used to describe the three different aspects of writing a man page. First, there is the description of −mdoc macro command usage. Second is the description of a UNIX command with −mdoc macros, and third, the description of a command to a user in the verbal sense; that is, discussion of a command in the text of a man page.

In the first case, troff(1) macros are themselves a type of command; the general syntax for a troff command is:

.Xx argument1 argument2 ...

‘.Xx’ is a macro command, and anything following it are arguments to be processed. In the second case, the description of a UNIX command using the content macros is a bit more involved; a typical SYNOPSIS command line might be displayed as:

filter [−flag] 〈

infile 〉 〈

Here, filter is the command name and the bracketed string −flag is a flag argument designated as optional by the option brackets. In −mdoc terms, 〈

infile 〉 and 〈
〉 are called meta arguments; in this example, the user has to replace the meta expressions given in angle brackets with real file names. Note that in this document meta arguments are used to describe −mdoc commands; in most man pages, meta variables are not specifically written with angle brackets. The macros which formatted the above example:

.Nm filter
.Op Fl flag
.Ao Ar infile Ac Ao Ar outfile Ac

In the third case, discussion of commands and command syntax includes both examples above, but may add more detail. The arguments 〈

infile 〉 and 〈
〉 from the example above might be referred to as operands or file arguments. Some command line argument lists are quite long:


[−eiknqrstv] [−D variable] [−d flags] [−f makefile] [−I directory] [−j max_jobs] [variable=value] [target ...]

Here one might talk about the command make and qualify the argument, makefile, as an argument to the flag, −f, or discuss the optional file operand target. In the verbal context, such detail can prevent confusion, however the −mdoc package does not have a macro for an argument to a flag. Instead the ‘Ar’ argument macro is used for an operand or file argument like target as well as an argument to a flag like variable. The make command line was produced from:

.Nm make
.Op Fl eiknqrstv
.Op Fl D Ar variable
.Op Fl d Ar flags
.Op Fl f Ar makefile
.Op Fl I Ar directory
.Op Fl j Ar max_jobs
.Op Ar variable Ns = Ns Ar value
.Op Ar target ...

The ‘.Bk’ and ‘.Ek’ macros are explained in Keeps.

General Syntax
The manual domain and general text domain macros share a similar syntax with a few minor deviations; most notably, ‘.Ar’, ‘.Fl’, ‘.Nm’, and ‘.Pa’ differ only when called without arguments; and ‘.Fn’ and ‘.Xr’ impose an order on their argument lists. All content macros are capable of recognizing and properly handling punctuation, provided each punctuation character is separated by a leading space. If a command is given:

.Ar sptr, ptr),

The result is:

sptr, ptr),

The punctuation is not recognized and all is output in the font used by ‘.Ar’. If the punctuation is separated by a leading white space:

.Ar sptr , ptr ) ,

The result is:

sptr, ptr),

The punctuation is now recognized and output in the default font distinguishing it from the argument strings. To remove the special meaning from a punctuation character escape it with ‘\&’.

The following punctuation characters are recognized by −mdoc:

. , : ; (
) [ ] ? !

Troff is limited as a macro language, and has difficulty when presented with a string containing a member of the mathematical, logical or quotation set:


The problem is that troff may assume it is supposed to actually perform the operation or evaluation suggested by the characters. To prevent the accidental evaluation of these characters, escape them with ‘\&’. Typical syntax is shown in the first content macro displayed below, ‘.Ad’.


The address macro identifies an address construct.

Usage: .Ad 〈

address 〉 ...

.Ad addr1


.Ad addr1 .


.Ad addr1 , file2

addr1, file2

.Ad f1 , f2 , f3 :

f1, f2, f3:

.Ad addr ) ) ,


The default width is 12n.

Author Name
The ‘.An’ macro is used to specify the name of the author of the item being documented, or the name of the author of the actual manual page.

Usage: .An 〈

author name 〉 ...

.An "Joe Author"

Joe Author

.An "Joe Author" ,

Joe Author,

.An "Joe Author" Aq

Joe Author 〈〉

.An "Joe Author" ) ) ,

Joe Author)),

The default width is 12n.

In the AUTHORS section, the ‘.An’ command causes a line break allowing each new name to appear on its own line. If this is not desirable,

.An -nosplit

call will turn this off. To turn splitting back on, write

.An -split

The .Ar argument macro may be used whenever an argument is referenced. If called without arguments, the ‘file ...’ string is output.

Usage: .Ar [

argument〉 ] ...


file ...

.Ar file1


.Ar file1 .


.Ar file1 file2

file1 file2

.Ar f1 f2 f3 :

f1 f2 f3:

.Ar file ) ) ,


The default width is 12n.

Configuration Declaration (Section Four Only)
The ‘.Cd’ macro is used to demonstrate a config(8) declaration for a device interface in a section four manual.

Usage: .Cd 〈

argument 〉 ...

.Cd "device le0 at scode?"

device le0 at scode?

In the SYNOPSIS section a ‘.Cd’ command causes a line break before and after its arguments are printed.

The default width is 12n.

Command Modifiers
The command modifier is identical to the ‘.Fl’ (flag) command with the exception that the ‘.Cm’ macro does not assert a dash in front of every argument. Traditionally flags are marked by the preceding dash, however, some commands or subsets of commands do not use them. Command modifiers may also be specified in conjunction with interactive commands such as editor commands. See Flags.

The default width is 10n.

Defined Variables
A variable (or constant) which is defined in an include file is specified by the macro ‘.Dv’.

Usage: .Dv 〈

defined variable 〉 ...





The default width is 12n.

The ‘.Er’ errno macro specifies the error return value for section 2, 3, and 9 library routines. The second example below shows ‘.Er’ used with the ‘.Bq’ general text domain macro, as it would be used in a section two manual page.

Usage: .Er 〈

errno type 〉 ...



.Er ENOENT ) ;




The default width is 17n.

Environment Variables
The ‘.Ev’ macro specifies an environment variable.

Usage: .Ev 〈

argument 〉 ...



.Ev PATH .


.Ev PRINTER ) ) ,


The default width is 15n.

The ‘.Fl’ macro handles command line flags. It prepends a dash, ‘−’, to the flag. For interactive command flags, which are not prepended with a dash, the ‘.Cm’ (command modifier) macro is identical, but without the dash.

Usage: .Fl 〈

argument 〉 ...


.Fl cfv


.Fl cfv .


.Cm cfv .


.Fl s v t

−s −v −t

.Fl − ,


.Fl xyz ) ,


.Fl |


The ‘.Fl’ macro without any arguments results in a dash representing stdin/stdout. Note that giving ‘.Fl’ a single dash will result in two dashes.

The default width is 12n.

Function Declarations
The ‘.Fd’ macro is used in the SYNOPSIS section with section two or three functions. It is neither callable nor parsed.

Usage: .Fd 〈

argument 〉 ...

.Fd "#include <sys/types.h>"

#include <sys/types.h>

In the SYNOPSIS section a ‘.Fd’ command causes a line break if a function has already been presented and a break has not occurred. This leaves a nice vertical space in between the previous function call and the declaration for the next function.

The ‘.In’ macro, while in the SYNOPSIS section, represents the #include statement, and is the short form of the above example. It specifies the C header file as being included in a C program. It also causes a line break.

While not in the SYNOPSIS section, it represents the header file enclosed in angle brackets.

Usage: .In 〈

header file 〉

.In stdio.h

#include <stdio.h>

.In stdio.h


Function Types
This macro is intended for the SYNOPSIS section. It may be used anywhere else in the man page without problems, but its main purpose is to present the function type in kernel normal form for the SYNOPSIS of sections two and three (it causes a line break, allowing the function name to appear on the next line).

Usage: .Ft 〈

type 〉 ...

.Ft struct stat

struct stat

Functions (Library Routines)
The ‘.Fn’ macro is modeled on ANSI C conventions.

Usage: .Fn 〈

function 〉 [

parameter〉 ] ...

.Fn getchar


.Fn strlen ) ,


.Fn align "char *ptr" ,

align(char *ptr),

Note that any call to another macro signals the end of the ‘.Fn’ call (it will insert a closing parenthesis at that point).

For functions with many parameters (which is rare), the macros ‘.Fo’ (function open) and ‘.Fc’ (function close) may be used with ‘.Fa’ (function argument).


.Ft int
.Fo res_mkquery
.Fa "int op"
.Fa "char *dname"
.Fa "int class"
.Fa "int type"
.Fa "char *data"
.Fa "int datalen"
.Fa "struct rrec *newrr"
.Fa "char *buf"
.Fa "int buflen"



res_mkquery(int op, char *dname, int class, int type, char *data, int datalen, struct rrec *newrr, char *buf, int buflen)

In the SYNOPSIS section, the function will always begin at the beginning of line. If there is more than one function presented in the SYNOPSIS section and a function type has not been given, a line break will occur, leaving a nice vertical space between the current function name and the one prior.

The default width values of ‘.Fn’ and ‘.Fo’ are 12n and 16n, respectively.

Function Arguments
The ‘.Fa’ macro is used to refer to function arguments (parameters) outside of the SYNOPSIS section of the manual or inside the SYNOPSIS section if the enclosure macros ‘.Fo’ and ‘.Fc’ instead of ‘.Fn’ are used. ‘.Fa’ may also be used to refer to structure members.

Usage: .Fa 〈

function argument 〉 ...

.Fa d_namlen ) ) ,


.Fa iov_len


The default width is 12n.

Return Values
The ‘.Rv’ macro generates text for use in the RETURN VALUES section.

Usage: .Rv [

-std ] [〈
function 〉 ...]

For example, ‘.Rv -std atexit’ produces:

The atexit() function returns the value 0 if successful; otherwise the value −1 is returned and the global variable errno is set to indicate the error.

The −std option is valid only for manual page sections 2 and 3. Currently, this macro does nothing if used without the −std flag.

Exit Status
The ‘.Ex’ macro generates text for use in the DIAGNOSTICS section.

Usage: .Ex [

-std ] [〈
utility 〉 ...]

For example, ‘.Ex -std cat’ produces:

The cat utility exits 0 on success, and >0 if an error occurs.

The −std option is valid only for manual page sections 1, 6 and 8. Currently, this macro does nothing if used without the −std flag.

Interactive Commands
The ‘.Ic’ macro designates an interactive or internal command.

Usage: .Ic 〈

argument 〉 ...

.Ic :wq


.Ic "do while {...}"

do while {...}

.Ic setenv , unsetenv

setenv, unsetenv

The default width is 12n.

Library Names
The ‘.Lb’ macro is used to specify the library where a particular function is compiled in.

Usage: .Lb 〈

argument 〉 ...

Available arguments to ‘.Lb’ and their results are:


ARM Architecture Library (libarm, −larm)


ARM32 Architecture Library (libarm32, −larm32)


Standard C Library (libc, −lc)


Curses Development Kit Library (libcdk, −lcdk)


Compatibility Library (libcompat, −lcompat)


Crypt Library (libcrypt, −lcrypt)


Curses Library (libcurses, −lcurses)


Line Editor and History Library (libedit, −ledit)


Event Notification Library (libevent, −levent)


Curses Form Library (libform, −lform)


i386 Architecture Library (libi386, −li386)


Internationalized Message Handling Library (libintl, −lintl)


IPsec Policy Control Library (libipsec, −lipsec)


Kernel Data Access Library (libkvm, −lkvm)


Math Library (libm, −lm)


m68k Architecture Library (libm68k, −lm68k)


Magic Number Recognition Library (libmagic, −lmagic)


Curses Menu Library (libmenu, −lmenu)


OSS Audio Emulation Library (libossaudio, −lossaudio)


Pluggable Authentication Module Library (libpam, −lpam)


Packet Capture Library (libpcap, −lpcap)


PCI Bus Access Library (libpci, −lpci)


Performance Monitoring Counters API (libpmc, −lpmc)


POSIX Compatibility Library (libposix, −lposix)


POSIX Threads Library (libpthread, −lpthread)


DNS Resolver Library (libresolv, −lresolv)


POSIX Real-time Library (librt, −lrt)


Termcap Access Library (libtermcap, −ltermcap)


USB Human Interface Devices Library (libusbhid, −lusbhid)


System Utilities Library (libutil, −lutil)


x86_64 Architecture Library (libx86_64, −lx86_64)


Compression Library (libz, −lz)

Local, OS-specific additions might be found in the file mdoc.local; look for strings named ‘str-Lb-XXX’. ‘XXX’ then denotes the keyword to be used with the ‘.Lb’ macro.

In the LIBRARY section an ‘.Lb’ command causes a line break before and after its arguments are printed.

The ‘.Li’ literal macro may be used for special characters, variable constants, etc. -- anything which should be displayed as it would be typed.

Usage: .Li 〈

argument 〉 ...

.Li \en


.Li M1 M2 M3 ;

M1 M2 M3;

.Li cntrl-D ) ,


.Li 1024 ...

1024 ...

The default width is 16n.

The ‘.Nm’ macro is used for the document title or subject name. It has the peculiarity of remembering the first argument it was called with, which should always be the subject name of the page. When called without arguments, ‘.Nm’ regurgitates this initial name for the sole purpose of making less work for the author. Note: A section two or three document function name is addressed with the ‘.Nm’ in the NAME section, and with ‘.Fn’ in the SYNOPSIS and remaining sections. For interactive commands, such as the ‘while’ command keyword in csh(1), the ‘.Ic’ macro should be used. While ‘.Ic’ is nearly identical to ‘.Nm’, it can not recall the first argument it was invoked with.

Usage: .Nm [

argument〉 ] ...

.Nm groff_mdoc


.Nm \-mdoc


.Nm foo ) ) ,


.Nm :


The default width is 10n.

The ‘.Op’ macro places option brackets around any remaining arguments on the command line, and places any trailing punctuation outside the brackets. The macros ‘.Oo’ and ‘.Oc’ (which produce an opening and a closing option bracket respectively) may be used across one or more lines or to specify the exact position of the closing parenthesis.

Usage: .Op [

option〉 ] ...



.Op Fl k


.Op Fl k ) .


.Op Fl k Ar kookfile

[−k kookfile]

.Op Fl k Ar kookfile ,

[−k kookfile],

.Op Ar objfil Op Ar corfil

[objfil [corfil]]

.Op Fl c Ar objfil Op Ar corfil ,

[−c objfil [corfil]],

.Op word1 word2

[word1 word2]

.Li .Op Oo Ao option Ac Oc ...

.Op [

option〉 ] ...

Here a typical example of the ‘.Oo’ and ‘.Oc’ macros:

.Op Fl k Ar kilobytes
.Op Fl i Ar interval
.Op Fl c Ar count



[−k kilobytes] [−i interval] [−c count] ]

The default width values of ‘.Op’ and ‘.Oo’ are 14n and 10n, respectively.

The ‘.Pa’ macro formats path or file names. If called without arguments, the ‘~’ string is output, which represents the current user’s home directory.

Usage: .Pa [

pathname〉 ] ...



.Pa /usr/share


.Pa /tmp/fooXXXXX ) .


The default width is 32n.

The ‘.St’ macro replaces standard abbreviations with their formal names.

Usage: .St 〈

abbreviation 〉 ...

Available pairs for ‘‘Abbreviation/Formal Name’’ are:



ANSI X3.159-1989 (‘‘ANSI C89’’)


ANSI X3.159-1989 (‘‘ANSI C89’’)


ISO/IEC 9899:1990 (‘‘ISO C90’’)


ISO/IEC 9899:1990 (‘‘ISO C90’’)


ISO/IEC 9899:1999 (‘‘ISO C99’’)

POSIX Part 1: System API


ISO/IEC 9945-1:1990 (‘‘POSIX.1’’)


ISO/IEC 9945-1:1996 (‘‘POSIX.1’’)


IEEE Std 1003.1 (‘‘POSIX.1’’)


IEEE Std 1003.1-1988 (‘‘POSIX.1’’)


ISO/IEC 9945-1:1990 (‘‘POSIX.1’’)


ISO/IEC 9945-1:1996 (‘‘POSIX.1’’)


IEEE Std 1003.1b-1993 (‘‘POSIX.1’’)


IEEE Std 1003.1c-1995 (‘‘POSIX.1’’)


IEEE Std 1003.1g-2000 (‘‘POSIX.1’’)


IEEE Std 1003.1i-1995 (‘‘POSIX.1’’)


IEEE Std 1003.1-2001 (‘‘POSIX.1’’)


IEEE Std 1003.1-2004 (‘‘POSIX.1’’)

POSIX Part 2: Shell and Utilities


ISO/IEC 9945-2:1993 (‘‘POSIX.2’’)


IEEE Std 1003.2 (‘‘POSIX.2’’)


IEEE Std 1003.2-1992 (‘‘POSIX.2’’)


IEEE Std 1003.2a-1992 (‘‘POSIX.2’’)



Version 2 of the Single UNIX Specification (‘‘SUSv2’’)


System V Interface Definition, Fourth Edition (‘‘SVID4’’)


X/Open System Interface Definitions Issue 5 (‘‘XBD5’’)


X/Open Commands and Utilities Issue 5 (‘‘XCU5’’)


X/Open Curses Issue 4, Version 2 (‘‘XCURSES4.2’’)


X/Open Networking Services Issue 5 (‘‘XNS5’’)


X/Open Networking Services Issue 5.2 (‘‘XNS5.2’’)


X/Open Portability Guide Issue 3 (‘‘XPG3’’)


X/Open Portability Guide Issue 4 (‘‘XPG4’’)


X/Open Portability Guide Issue 4, Version 2 (‘‘XPG4.2’’)


X/Open System Interfaces and Headers Issue 5 (‘‘XSH5’’)



IEEE Std 754-1985


ISO/IEC 8802-3:1989

Variable Types
The ‘.Vt’ macro may be used whenever a type is referenced. In the SYNOPSIS section, it causes a line break (useful for old style variable declarations).

Usage: .Vt 〈

type 〉 ...

.Vt extern char *optarg ;

extern char *optarg;

.Vt FILE *


Generic variable reference.

Usage: .Va 〈

variable 〉 ...

.Va count


.Va settimer ,


.Va "int *prt" ) :

int *prt):

.Va "char s" ] ) ) ,

char s])),

The default width is 12n.

Manual Page Cross References
The ‘.Xr’ macro expects the first argument to be a manual page name. The optional second argument, if a string (defining the manual section), is put into parentheses.

Usage: .Xr 〈

man page name 〉 [

section〉 ] ...

.Xr mdoc


.Xr mdoc ,


.Xr mdoc 7


.Xr xinit 1x ;


The default width is 10n.


AT&T Macro

Usage: .At [

version〉 ] ...



.At v6 .

Version 6 AT&T UNIX.

The following values for 〈

version 〉 are possible:

32v, v1, v2, v3, v4, v5, v6, v7, V, V.1, V.2, V.3, V.4

BSD Macro

Usage: .Bx {

-alpha | -beta | -devel } ...

.Bx [

version〉 [

release〉] ] ...



.Bx 4.3 .


.Bx −devel

BSD (currently under development)

version 〉 will be prepended to the string ‘BSD’. The following values for 〈
release 〉 are possible:

Reno, reno, Tahoe, tahoe, Lite, lite, Lite2, lite2

NetBSD Macro

Usage: .Nx [

version〉 ] ...



.Nx 1.4 .

NetBSD 1.4.

For possible values of 〈

version 〉 see the description of the ‘.Os’ command above in section TITLE MACROS.

FreeBSD Macro

Usage: .Fx [

version〉 ] ...



.Fx 2.2 .

FreeBSD 2.2.

For possible values of 〈

version 〉 see the description of the ‘.Os’ command above in section TITLE MACROS.

MidnightBSD Macro