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Manual Reference Pages  - GROFF_MDOC (7)

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groff_mdoc - reference for groff’s mdoc implementation

CONTENTS

Synopsis
Description
Conventions
     Addresses
     Errno’s
     Flags
     Literals
     Names
     Options
     Pathnames
     Standards
     Variables
     Symbolics
     Mathematical Symbols
     Keeps
Diagnostics
Files
Bugs

groff-m doc

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:

1. TROFF IDIOSYNCRASIES

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

2. A MANUAL PAGE TEMPLATE
3. CONVENTIONS
4. TITLE MACROS
5. INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS

   What’s in a Name ...
   General Syntax

6. MANUAL DOMAIN

   Addresses
   Author Name
   Arguments
   Configuration Declarations (Section Four Only)
   Command Modifiers
   Defined Variables
   Errno’s
   Environment Variables
   Flags
   Function Declarations
   Function Types
   Functions (Library Routines)
   Function Arguments
   Return Values
   Exit Status
   Interactive Commands
   Library Names
   Literals
   Names
   Options
   Pathnames
   Standards
   Variable Types
   Variables
   Manual Page Cross References

7. GENERAL TEXT DOMAIN

   AT&T Macro
   BSD Macro
   NetBSD Macro
   FreeBSD 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
   Symbolics
   Mathematical Symbols
   References and Citations
   Trade Names (or Acronyms and Type Names)
   Extended Arguments

8. PAGE STRUCTURE DOMAIN

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

9. MISCELLANEOUS MACROS
10. PREDEFINED STRINGS
11. DIAGNOSTICS
12. FORMATTING WITH GROFF, TROFF, AND NROFF
13. FILES
14. SEE ALSO
15. BUGS

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.

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.

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 q]char *strq]’

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

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\ \&’.

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

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 ‘q]’ 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:

The
.Ql .
character.
.Pp
The
.Ql \&.
character.
.Pp
.No test .
test
.Pp
.No test.
test

gives

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]
.Sh NAME
.Nm name
.Nd one line description of name
.\" This next command is for sections 2 and 3 only.
.\" .Sh LIBRARY
.Sh SYNOPSIS
.Sh DESCRIPTION
.\" The following commands should be uncommented and
.\" used where appropriate.
.\" .Sh IMPLEMENTATION NOTES
.\" This next command is for sections 2, 3 and 9 function
.\" return values only.
.\" .Sh RETURN VALUES
.\" This next command is for sections 1, 6, 7 and 8 only.
.\" .Sh ENVIRONMENT
.\" .Sh FILES
.\" .Sh EXAMPLES
.\" This next command is for sections 1, 6, 7, 8 and 9 only
.\"     (command return values (to shell) and
.\"     fprintf/stderr type diagnostics).
.\" .Sh DIAGNOSTICS
.\" .Sh COMPATIBILITY
.\" This next command is for sections 2, 3 and 9 error
.\"     and signal handling only.
.\" .Sh ERRORS
.\" .Sh SEE ALSO
.\" .Sh STANDARDS
.\" .Sh HISTORY
.\" .Sh AUTHORS
.\" .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.

Example:

.Xx Xo	<foo> .Brq 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 q]foo <bar>q]’.

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.

.Dt Xo	[<documenttitle>] [<sectionnumber>] [<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 operating-system], the following sections are defined:
1      volume-operating-system] volume-ds-1] 2      volume-operating-system] volume-ds-2] 3      volume-operating-system] volume-ds-3] 4      volume-operating-system] volume-ds-4] 5      volume-operating-system] volume-ds-5] 6      volume-operating-system] volume-ds-6] 7      volume-operating-system] volume-ds-7] 8      volume-operating-system] volume-ds-8] 9      volume-operating-system] volume-ds-9]

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

USD      volume-ds-USD] PS1      volume-ds-PS1] AMD      volume-ds-AMD] SMM      volume-ds-SMM] URM      volume-ds-URM] PRM      volume-ds-PRM] KM      volume-ds-KM] IND      volume-ds-IND] LOCAL      volume-ds-LOCAL] CON      volume-ds-CON]

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: # we use ‘No’ to avoid hyphenation

alpha, amiga, arc, arm26, arm32, atari, bebox, cobalt, evbsh3,

hp300, hpcmips, i386, luna68k, m68k, mac68k, macppc, mips,

mmeye, mvme68k, news68k, newsmips, next68k, ofppc, pc532, pmax,

powerpc, prep, sgimips, sh3, sparc, sparc64, sun3, tahoe, vax,

x68k

In the following examples, the left (which is identical to the right) and the middle part of the manual page header strings are shown.

.Dt FOO 7	‘FOO(7)’ ‘volume-operating-system] volume-ds-7]’
.Dt FOO 2 i386	‘FOO(2)’ ‘volume-operating-system]/volume-as-i386] volume-ds-2]’
.Dt FOO q]q] 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.

.Os Xo	[<operatingsystem>] [<release>]
	If the first parameter is empty, the default 'operating-system]' 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.

ATT	7th, 7, III, 3, V, V.2, V.3, V.4
BSD	3, 4, 4.1, 4.2, 4.3, 4.3t, 4.3T, 4.3r, 4.3R, 4.4
NetBSD	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, 1.5, 1.6
FreeBSD
	1.0, 1.1, 1.1.5, 1.1.5.1, 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, 4.2, 4.3, 4.4, 4.5, 5.0

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 Otherwise, the current date is used, ignoring the parameters. This macro is neither callable nor parsed.

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<outfile>>

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 <outfile> 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 <outfile> from the example above might be referred to as operands or file arguments. Some command line argument lists are quite long:

make	[-eiknqrstv] [-D variable] [-d flags] [-f makefile] [-I directory] [-j max_jobs] [variable = value] .Bk [target ...] .Ek

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
.Bk
.Op Ar target ...
.Ek

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

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 ‘\&’.

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	addr1
.Ad addr1 .	addr1.
.Ad addr1 , file2	addr1, file2
.Ad f1 , f2 , f3 :	f1, f2, f3:
.Ad addr ) ) ,	addr)),

The default width is 12n.

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 q]Joe Authorq]	.An Joe Author
.An q]Joe Authorq] ,	.An Joe Author ,
.An q]Joe Authorq] Aq nobody@FreeBSD.org	.An Joe Author Aq nobody@FreeBSD.org
.An q]Joe Authorq] ) ) ,	.An 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 '' string is output.

    Usage: .Ar[<argument...]>

.Ar
.Ar file1	file1
.Ar file1 .	file1.
.Ar file1 file2	file1 file2
.Ar f1 f2 f3 :	f1 f2 f3:
.Ar file ) ) ,	file)),

The default width is 12n.

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

    Usage: .Cd<argument...>

.Cd q]device le0 at scode?q]	.Cd 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.

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.

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

    Usage: .Dv<defined variable...>

.Dv MAXHOSTNAMELEN	MAXHOSTNAMELEN
.Dv TIOCGPGRP )	TIOCGPGRP)

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	ENOENT
.Er ENOENT ) ;	ENOENT);
.Bq Er ENOTDIR	[ENOTDIR]

The default width is 17n.

The ‘.Ev’ macro specifies an environment variable.

    Usage: .Ev<argument...>

.Ev DISPLAY	DISPLAY
.Ev PATH .	PATH.
.Ev PRINTER ) ) ,	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
.Fl cfv	-cfv
.Fl cfv .	-cfv .
.Cm cfv .	cfv.
.Fl s v t	-s -v -t
.Fl - ,	-- ,
.Fl xyz ) ,	-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.

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 q]#include <sys/types.h>q]	.Fd #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’ ( #include statement) macro 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, and is neither callable nor parsed.

    Usage: .In<header file>

.In stdio.h	.In stdio.h

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

The ‘.Fn’ macro is modeled on ANSI~C conventions.

    Usage: .Fn<function[<parameter...]>>

.Fn getchar	getchar
.Fn strlen ) ,	strlen),
.Fn align q]char *ptrq] ,	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).

Example:

.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"
.Fc

Produces:

 int


.Fo res_mkquery

 int op

 char *dname

 int class

 int type

 char *data

 int datalen

 struct rrec *newrr

 char *buf

 int buflen


.Fc 

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.

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 ) ) ,	d_namlen)),
.Fa iov_len	iov_len

The default width is 12n.

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

    Usage: .Rv[-std[<function...>]]

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

# a small hack to suppress a warning message




.Rv -std atexit

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

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

    Usage: .Ex[-std[<utility...>]]

For example, ‘.Ex -std cat’ produces:

# a small hack to suppress a warning message




.Ex -std cat

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.

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

    Usage: .Ic<argument...>

.Ic :wq	:wq
.Ic q]do while {...}q]	do while {...}
.Ic setenv , unsetenv	setenv, unsetenv

The default width is 12n.

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:

libarm32	.Lb libarm32
libc	.Lb libc
libcompat	.Lb libcompat
libcrypt	.Lb libcrypt
libcurses	.Lb libcurses
libedit	.Lb libedit
libi386	.Lb libi386
libipsec	.Lb libipsec
libkvm	.Lb libkvm
libm	.Lb libm
libmenu	.Lb libmenu
libossaudio
	.Lb libossaudio
libposix	.Lb libposix
libresolv	.Lb libresolv
libtermcap	.Lb libtermcap
libutil	.Lb libutil
libz	.Lb libz

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.

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	\n
.Li M1 M2 M3 ;	M1 M2 M3;
.Li cntrl-D ) ,	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	groff_mdoc
.Nm \-mdoc	-mdoc
.Nm foo ) ) ,	foo)),
.Nm :	groff_mdoc:

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	[]
.Op Fl k	[-k]
.Op Fl k ) .	[-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[<options...]>

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

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

Produces:

[

[-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
.Pa /usr/share	/usr/share
.Pa /tmp/fooXXXXX ) .	/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/ISO C

-ansiC	-ansiC
-ansiC-89	-ansiC-89
-isoC	-isoC
-isoC-99	-isoC-99

POSIX Part 1: System API

-iso9945-1-90	-iso9945-1-90
-iso9945-1-96	-iso9945-1-96
-p1003.1	-p1003.1
-p1003.1-88	-p1003.1-88
-p1003.1-90	-p1003.1-90
-p1003.1-96	-p1003.1-96
-p1003.1b-93	-p1003.1b-93
-p1003.1c-95	-p1003.1c-95
-p1003.1g-2000
	-p1003.1g-2000
-p1003.1i-95	-p1003.1i-95

POSIX Part 2: Shell and Utilities

-iso9945-2-93	-iso9945-2-93
-p1003.2	-p1003.2
-p1003.2-92	-p1003.2-92
-p1003.2a-92	-p1003.2a-92

X/Open

-susv2	-susv2
-svid4	-svid4
-xbd5	-xbd5
-xcu5	-xcu5
-xcurses4.2	-xcurses4.2
-xns5	-xns5
-xns5.2	-xns5.2
-xpg3	-xpg3
-xpg4	-xpg4
-xpg4.2	-xpg4.2
-xsh5	-xsh5

Miscellaneous

-ieee754	-ieee754
-iso8802-3	-iso8802-3

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 ;	.Vt extern char *optarg ;
.Vt FILE *	.Vt FILE *

Generic variable reference.

    Usage: .Va<variable...>

.Va count	count
.Va settimer ,	settimer,
.Va q]int *prtq] ) :	int *prt):
.Va q]char sq] ] ) ) ,	char s])),

The default width is 12n.

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	mdoc
.Xr mdoc ,	mdoc,
.Xr mdoc 7	mdoc(7)
.Xr xinit 1x ;	xinit(1x);

The default width is 10n.

    Usage: .At[<version...]>

.At	AT&T
.At v6 .	AT&T v6 .

The following values for <version> are possible:

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

    Usage: .Bx Bro -alpha | -beta | -devel Brc ...

    .Bx[<version[<release...]]>>

.Bx	BSD
.Bx 4.3 .	BSD 4.3 .
.Bx -devel	BSD -devel

<version> will be prepended to the string 'Bx'. The following values for <release> are possible:

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

    Usage: .Nx[<version...]>

.Nx	.Nx
.Nx 1.4 .	.Nx 1.4 .

For possible values of <version> see the description of the ‘.Os’ command above in section TITLE MACROS.

    Usage: .Fx[<version...]>

.Fx	.Fx
.Fx 2.2 .	.Fx 2.2 .

For possible values of <version> see the description of the ‘.Os’ command above in section TITLE MACROS.

    Usage: .Ox[<version...]>

.Ox 1.0	.Ox 1.0

    Usage: .Bsx[<version...]>

.Bsx 1.0	.Bsx 1.0

    Usage: .Ux ...

.Ux	Unix

Text may be stressed or emphasized with the ‘.Em’ macro. The usual font for emphasis is italic.

    Usage: .Em<argument...>

.Em does not	does not
.Em exceed 1024 .	exceed 1024.
.Em vide infra ) ) ,	vide infra)),

The default width is 10n.

The ‘.Bf’ font mode must be ended with the ‘.Ef’ macro (the latter takes no arguments). Font modes may be nested within other font modes.

‘.Bf’ has the following syntax:

    .Bf<font mode>

<font mode> must be one of the following three types:

Em |-emphasis	Same as if the ‘.Em’ macro was used for the entire block of text.
Li |-literal	Same as if the ‘.Li’ macro was used for the entire block of text.
Sy |-symbolic	Same as if the ‘.Sy’ macro was used for the entire block of text.

Both macros are neither callable nor parsed.

The concept of enclosure is similar to quoting. The object being to enclose one or more strings between a pair of characters like quotes or parentheses. The terms quoting and enclosure are used interchangeably throughout this document. Most of the one-line enclosure macros end in small letter ‘q’ to give a hint of quoting, but there are a few irregularities. For each enclosure macro there is also a pair of open and close macros which end in small letters ‘o’ and ‘c’ respectively.

# XXX

 Quote       Open       Close       Function       Result

.Aq       .Ao       .Ac       Angle Bracket Enclosure      <string>

.Bq       .Bo       .Bc       Bracket Enclosure      [string]

.Brq       .Bro       .Brc       Brace Enclosure       Bro string Brc

.Dq       .Do       .Dc       Double Quote      "string"

.Eq       .Eo       .Ec       Enclose String (in XX)       XXstringXX

.Pq       .Po       .Pc       Parenthesis Enclosure      (string)

.Ql                   Quoted Literal      'stringor string'

.Qq       .Qo       .Qc       Straight Double Quote      "string"

.Sq       .So       .Sc       Single Quote      'string'

All macros ending with 'q' and 'o' have a default width value of 12n.

.Eo, .Ec	These macros expect the first argument to be the opening and closing strings respectively.
.Es, .En	Due to the nine-argument limit in the original troff program two other macros have been implemented which are now rather obsolete: ‘.Es’ takes the first and second parameter as the left and right enclosure string, which are then used to enclose the arguments of ‘.En’. The default width value is 12n for both macros.
.Eq	The first and second arguments of this macro are the opening and closing strings respectively, followed by the arguments to be enclosed.
.Ql	The quoted literal macro behaves differently in troff and nroff mode. If formatted with nroff, a quoted literal is always quoted. If formatted with troff, an item is only quoted if the width of the item is less than three constant width characters. This is to make short strings more visible where the font change to literal (constant width) is less noticeable. The default width is 16n.
.Pf	The prefix macro suppresses the whitespace between its first and second argument:

.Pf ( Fa name2	( name2

The default width is 12n.

The ‘.Ns’ macro (see below) performs the analogous suffix function.

.Ap	The ‘.Ap’ macro inserts an apostrophe and exits any special text modes, continuing in ‘.No’ mode.

Examples of quoting:

.Aq	<>
.Aq Pa ctype.h ) ,	<ctype.h>),
.Bq	[]
.Bq Em Greek , French .	[Greek, French].
.Dq	""
.Dq string abc .	"string abc".
.Dq '^[A-Z]'	"'^[A-Z]'"
.Ql man mdoc	‘man mdoc’
.Qq	""
.Qq string ) ,	"string"),
.Qq string Ns ),	"string ),"
.Sq	''
.Sq string	'string'
.Em or Ap ing	or Ap ing

For a good example of nested enclosure macros, see the ‘.Op’ option macro. It was created from the same underlying enclosure macros as those presented in the list above. The ‘.Xo’ and ‘.Xc’ extended argument list macros are discussed below.

The ‘.No’ macro can be used in a macro command line for parameters which should not be formatted. Be careful to add ‘\&’ to the word ‘No’ if you really want that English word (and not the macro) as a parameter.

    Usage: .No<argument...>

.No test Ta with Ta tabs	test      with      tabs

The default width is 12n.

The ‘.Ns’ macro suppresses insertion of a space between the current position and its first parameter. For example, it is useful for old style argument lists where there is no space between the flag and argument:

    Usage: ...<argumentNs[<argument...]>>

    .Ns<argument...>

.Op Fl I Ns Ar directory	[-Idirectory]

Note: The ‘.Ns’ macro always invokes the ‘.No’ macro after eliminating the space unless another macro name follows it. If used as a command (i.e., the second form above in the 'Usage' line), ‘.Ns’ is identical to ‘.No’.

The ‘.Sx’ macro designates a reference to a section header within the same document.

    Usage: .Sx<section reference...>

.Sx FILES	FILES

The default width is 16n.

The symbolic emphasis macro is generally a boldface macro in either the symbolic sense or the traditional English usage.

    Usage: .Sy<symbol...>

.Sy Important Notice	Important Notice

The default width is 6n.

Use this macro for mathematical symbols and similar things.

    Usage: .Ms<math symbol...>

.Ms sigma	.Ms sigma

The default width is 6n.

The following macros make a modest attempt to handle references. At best, the macros make it convenient to manually drop in a subset of refer(1) style references.

.Rs	Reference start (does not take arguments). Causes a line break in the SEE ALSO section and begins collection of reference information until the reference end macro is read.
.Re	Reference end (does not take arguments). The reference is printed.
.%A	Reference author name; one name per invocation.
.%B	Book title.
.%C	City/place (not implemented yet).
.%D	Date.
.%I	Issuer/publisher name.
.%J	Journal name.
.%N	Issue number.
.%O	Optional information.
.%P	Page number.
.%Q	Corporate or foreign author.
.%R	Report name.
.%T	Title of article.
.%V	Volume.

Macros beginning with ‘%’ are not callable but accept multiple arguments in the usual way. Only the ‘.Tn’ macro is handled properly as a parameter; other macros will cause strange output. ‘.%B’ and ‘.%T’ can be used outside of the ‘.Rs/.Re’ environment.

Example:

.Rs
.%A "Matthew Bar"
.%A "John Foo"
.%T "Implementation Notes on foobar(1)"
.%R "Technical Report ABC-DE-12-345"
.%Q "Drofnats College, Nowhere"
.%D "April 1991"
.Re

produces

.Rs 





 Implementation Notes on foobar(1)








.Re 

The trade name macro prints its arguments in a smaller font. Its intended use is to imitate a small caps fonts for uppercase acronyms.

    Usage: .Tn<symbol...>

.Tn DEC	DEC
.Tn ASCII	ASCII

The default width is 10n.

The .Xo and .Xc macros allow one to extend an argument list on a macro boundary for the ‘.It’ macro (see below). Note that .Xo and .Xc are implemented similarly to all other macros opening and closing an enclosure (without inserting characters, of course). This means that the following is true for those macros also.

Here is an example of ‘.Xo’ using the space mode macro to turn spacing off:

.Sm off
.It Xo Sy I Ar operation
.No \en Ar count No \en
.Xc
.Sm on

produces

.Sm off

\n count \n
	.Sm on

Another one:

.Sm off
.It Cm S No / Ar old_pattern Xo
.No / Ar new_pattern
.No / Op Cm g
.Xc
.Sm on

produces

.Sm off

S / old_pattern Xo	/ new_pattern / [g]
	.Sm on

Another example of ‘.Xo’ and enclosure macros: Test the value of a variable.

.It Xo
.Ic .ifndef
.Oo \&! Oc Ns Ar variable Oo
.Ar operator variable ...
.Oc Xc

produces

.ifndef [!variable[] operator variable ... Xc]

The following ‘.Sh’ section header macros are required in every man page. The remaining section headers are recommended at the discretion of the author writing the manual page. The ‘.Sh’ macro is parsed but not generally callable. It can be used as an argument in a call to ‘.Sh’ only; it then reactivates the default font for ‘.Sh’.

The default width is 8n.

.Sh NAME	The ‘.Sh NAME’ macro is mandatory. If not specified, headers, footers and page layout defaults will not be set and things will be rather unpleasant. The NAME section consists of at least three items. The first is the ‘.Nm’ name macro naming the subject of the man page. The second is the name description macro, ‘.Nd’, which separates the subject name from the third item, which is the description. The description should be the most terse and lucid possible, as the space available is small. ‘.Nd’ first prints ‘-’, then all its arguments.
.Sh LIBRARY	This section is for section two and three function calls. It should consist of a single ‘.Lb’ macro call; see Library Names.
.Sh SYNOPSIS	The SYNOPSIS section describes the typical usage of the subject of a man page. The macros required are either ‘.Nm’, ‘.Cd’, or ‘.Fn’ (and possibly ‘.Fo’, ‘.Fc’, ‘.Fd’, and ‘.Ft’). The function name macro ‘.Fn’ is required for manual page sections~2 and~3; the command and general name macro ‘.Nm’ is required for sections 1, 5, 6, 7, and~8. Section~4 manuals require a ‘.Nm’, ‘.Fd’ or a ‘.Cd’ configuration device usage macro. Several other macros may be necessary to produce the synopsis line as shown below: cat [-benstuv] [] The following macros were used:     .Nm cat     .Op Fl benstuv     .Op Fl     .Ar
.Sh DESCRIPTION	In most cases the first text in the DESCRIPTION section is a brief paragraph on the command, function or file, followed by a lexical list of options and respective explanations. To create such a list, the ‘.Bl’ (begin list), ‘.It’ (list item) and ‘.El’ (end list) macros are used (see Lists and Columns below).
.Sh IMPLEMENTATION NOTES	Implementation specific information should be placed here.
.Sh RETURN VALUES	Sections 2, 3 and~9 function return values should go here. The ‘.Rv’ macro may be used to generate text for use in the RETURN VALUES section for most section 2 and 3 library functions; see Return Values.

The following ‘.Sh’ section headers are part of the preferred manual page layout and must be used appropriately to maintain consistency. They are listed in the order in which they would be used.

.Sh ENVIRONMENT	The ENVIRONMENT section should reveal any related environment variables and clues to their behavior and/or usage.
.Sh FILES	Files which are used or created by the man page subject should be listed via the ‘.Pa’ macro in the FILES section.
.Sh EXAMPLES	There are several ways to create examples. See the EXAMPLES section below for details.
.Sh DIAGNOSTICS	Diagnostic messages from a command should be placed in this section. The ‘.Ex’ macro may be used to generate text for use in the DIAGNOSTICS section for most section 1, 6 and~8 commands; see Exit Status.
.Sh COMPATIBILITY	Known compatibility issues (e.g. deprecated options or parameters) should be listed here.
.Sh ERRORS	Specific error handling, especially from library functions (man page sections 2, 3, and~9) should go here. The ‘.Er’ macro is used to specify an error (errno).
.Sh SEE ALSO	References to other material on the man page topic and cross references to other relevant man pages should be placed in the SEE ALSO section. Cross references are specified using the ‘.Xr’ macro. Currently refer(1) style references are not accommodated. It is recommended that the cross references are sorted on the section number, then alphabetically on the names within a section, and placed in that order and comma separated. Example: ls(1), ps(1), group(5), passwd(5)
.Sh STANDARDS	If the command, library function or file adheres to a specific implementation such as -p1003.2 or -ansiC this should be noted here. If the command does not adhere to any standard, its history should be noted in the HISTORY section.
.Sh HISTORY	Any command which does not adhere to any specific standards should be outlined historically in this section.
.Sh AUTHORS	Credits should be placed here. The ‘.An’ macro should be used to specify the name(s) of the person(s).
.Sh BUGS	Blatant problems with the topic go here.

User-specified ‘.Sh’ sections may be added; for example, this section was set with:

.Sh "PAGE STRUCTURE DOMAIN"

Subsection headers have exactly the same syntax as section headers: ‘.Ss’ is parsed but not generally callable. It can be used as an argument in a call to ‘.Ss’ only; it then reactivates the default font for ‘.Ss’.

The default width is 8n.

.Pp	The ‘.Pp’ paragraph command may be used to specify a line space where necessary. The macro is not necessary after a ‘.Sh’ or ‘.Ss’ macro or before a ‘.Bl’ or ‘.Bd’ macro (which both assert a vertical distance unless the -compact flag is given). The macro is neither callable nor parsed and takes no arguments; an alternative name is ‘.Lp’.