MAN(7)

NAME
man - man language reference

DESCRIPTION
The man language was historically used to format UNIX manuals. This reference document describes its syntax, structure, and usage.

Do not use man to write your manuals. Use the mdoc(7) language, instead.

A man document follows simple rules: lines beginning with the control character ‘’. are parsed for macros. Other lines are interpreted within the scope of prior macros:

    .SH Macro lines change control state.
    Other lines are interpreted within the current state.

INPUT ENCODING
man documents may contain only graphable 7-bit ASCII characters, the space character, and the tab character. All manuals must have UNIX line termination.

Blank lines are acceptable; where found, the output will assert a vertical space.

  Comments
Text following a ‘\’, whether in a macro or free-form text line, is ignored to the end of line. A macro line with only a control character and comment escape, ‘.\’, is also ignored. Macro lines with only a control character and optionally whitespace are stripped from input.

  Special Characters
Special characters may occur in both macro and free-form lines. Sequences begin with the escape character ‘\’ followed by either an open-parenthesis ‘(’ for two-character sequences; an open-bracket ‘[’ for n-character sequences (terminated at a close-bracket ‘’]); or a single one-character sequence. See mandoc_char(7) for a complete list. Examples include ‘\(em’ (em-dash) and ‘\e’ (back-slash).

  Text Decoration
Terms may be text-decorated using the ‘\f’ escape followed by an indicator: B (bold), I (italic), R (Roman), or P (revert to previous mode):

    \fBbold\fR \fIitalic\fP

A numerical representation 3, 2, or 1 (bold, italic, and Roman, respectively) may be used instead. A text decoration is only valid, if specified in free-form text, until the next macro invocation; if specified within a macro, it's only valid until the macro closes scope. Note that macros like BR open and close a font scope with each argument.

The ‘\f’ attribute is forgotten when entering or exiting a macro block.

  Whitespace
Whitespace consists of the space character. In free-form lines, whitespace is preserved within a line; unescaped trailing spaces are stripped from input (unless in a literal context). Blank free-form lines, which may include spaces, are permitted and rendered as an empty line.

In macro lines, whitespace delimits arguments and is discarded. If arguments are quoted, whitespace within the quotes is retained.

  Dates
The TH macro is the only man macro that requires a date. The form for this date is the ISO-8601 standard YYYY-MM-DD.

  Scaling Widths
Many macros support scaled widths for their arguments, such as stipulating a two-inch paragraph indentation with the following:

    .HP 2i

The syntax for scaled widths is ‘[+-]?[0-9]*.[0-9]*[:unit:]?’, where a decimal must be preceded or proceeded by at least one digit. Negative numbers, while accepted, are truncated to zero. The following scaling units are accepted:

c   centimetre
i   inch
P   pica (~1/6 inch)
p   point (~1/72 inch)
f   synonym for ‘u’
v   default vertical span
m   width of rendered ‘m’ (em) character
n   width of rendered ‘n’ (en) character
u   default horizontal span
M   mini-em (~1/100 em)

Using anything other than ‘m’, ‘n’, ‘u’, or ‘v’ is necessarily non-portable across output media.

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. Note: this differs from mdoc(7), which, if a unit is not provided, will instead interpret the string as literal text.

  Sentence Spacing
When composing a manual, make sure that sentences end at the end of a line. By doing so, front-ends will be able to apply the proper amount of spacing after the end of sentence (unescaped) period, exclamation mark, or question mark followed by zero or more non-sentence closing delimiters ( ‘’), ‘’], ‘'’, ‘"’).

MANUAL STRUCTURE
Each man document must contain the TH macro describing the document's section and title. It may occur anywhere in the document, although conventionally it appears as the first macro.

Beyond TH, at least one macro or text node must appear in the document. Documents are generally structured as follows:

    .TH FOO 1 2009-10-10
    .SH NAME
    \fBfoo\fR \(en a description goes here
    .\ .SH LIBRARY
    .\ For sections 2 & 3 only.
    .\ Not used in OpenBSD.
    .SH SYNOPSIS
    \fBfoo\fR [\fB\-options\fR] arguments...
    .SH DESCRIPTION
    The \fBfoo\fR utility processes files...
    .\ .SH IMPLEMENTATION NOTES
    .\ Not used in OpenBSD.
    .\ .SH RETURN VALUES
    .\ For sections 2, 3, & 9 only.
    .\ .SH ENVIRONMENT
    .\ For sections 1, 6, 7, & 8 only.
    .\ .SH FILES
    .\ .SH EXIT STATUS
    .\ For sections 1, 6, & 8 only.
    .\ .SH EXAMPLES
    .\ .SH DIAGNOSTICS
    .\ For sections 1, 4, 6, 7, & 8 only.
    .\ .SH ERRORS
    .\ For sections 2, 3, & 9 only.
    .\ .SH SEE ALSO
    .\ .BR foo ( 1 )
    .\ .SH STANDARDS
    .\ .SH HISTORY
    .\ .SH AUTHORS
    .\ .SH CAVEATS
    .\ .SH BUGS
    .\ .SH SECURITY CONSIDERATIONS
    .\ Not used in OpenBSD.

The sections in a man document are conventionally ordered as they appear above. Sections should be composed as follows:

NAME
The name(s) and a short description of the documented material. The syntax for this is generally as follows:

    \fBname\fR \(en description

LIBRARY
The name of the library containing the documented material, which is assumed to be a function in a section 2 or 3 manual. For functions in the C library, this may be as follows:

    Standard C Library (libc, -lc)

SYNOPSIS
Documents the utility invocation syntax, function call syntax, or device configuration.

For the first, utilities (sections 1, 6, and 8), this is generally structured as follows:

    \fBname\fR [-\fBab\fR] [-\fBc\fR\fIarg\fR] \fBpath\fR...

For the second, function calls (sections 2, 3, 9):

    .B char *name(char *\fIarg\fR);

And for the third, configurations (section 4):

    .B name* at cardbus? function?

Manuals not in these sections generally don't need a SYNOPSIS.

DESCRIPTION
This expands upon the brief, one-line description in NAME. It usually contains a break-down of the options (if documenting a command).

IMPLEMENTATION NOTES
Implementation-specific notes should be kept here. This is useful when implementing standard functions that may have side effects or notable algorithmic implications.

RETURN VALUES
This section documents the return values of functions in sections 2, 3, and 9.

ENVIRONMENT
Documents any usages of environment variables, e.g., environ(7).

FILES
Documents files used. It's helpful to document both the file name and a short description of how the file is used (created, modified, etc.).

EXIT STATUS
This section documents the command exit status for section 1, 6, and 8 utilities. Historically, this information was described in DIAGNOSTICS, a practise that is now discouraged.

EXAMPLES
Example usages. This often contains snippets of well-formed, well-tested invocations. Make sure that examples work properly!

DIAGNOSTICS
Documents error conditions. This is most useful in section 4 manuals. Historically, this section was used in place of EXIT STATUS for manuals in sections 1, 6, and 8; however, this practise is discouraged.

ERRORS
Documents error handling in sections 2, 3, and 9.

SEE ALSO
References other manuals with related topics. This section should exist for most manuals.

    .BR bar (1 ),

Cross-references should conventionally be ordered first by section, then alphabetically.

STANDARDS
References any standards implemented or used, such as

    IEEE Std 1003.2 (\(lqPOSIX.2\(rq)

If not adhering to any standards, the HISTORY section should be used.

HISTORY
A brief history of the subject, including where support first appeared.

AUTHORS
Credits to the person or persons who wrote the code and/or documentation. Authors should generally be noted by both name and email address.

CAVEATS
Common misuses and misunderstandings should be explained in this section.

BUGS
Known bugs, limitations, and work-arounds should be described in this section.

SECURITY CONSIDERATIONS
Documents any security precautions that operators should consider.

MACRO SYNTAX
Macros are one to three characters in length and begin with a control character, ‘’., at the beginning of the line. The ‘'’ macro control character is also accepted. An arbitrary amount of whitespace (spaces or tabs) may sit between the control character and the macro name. Thus, the following are equivalent:

    .PP
    .   PP

The man macros are classified by scope: line scope or block scope. Line macros are only scoped to the current line (and, in some situations, the subsequent line). Block macros are scoped to the current line and subsequent lines until closed by another block macro.

  Line Macros
Line macros are generally scoped to the current line, with the body consisting of zero or more arguments. If a macro is scoped to the next line and the line arguments are empty, the next line, which must be text, is used instead. Thus:

    .I
    foo

is equivalent to ‘.I foo’. If next-line macros are invoked consecutively, only the last is used. If a next-line macro is followed by a non-next-line macro, an error is raised, except for br, sp, and na.

The syntax is as follows:

    .YO [body...]
    [body...]

Macro | Arguments | Scope | Notes
AT | <=1 | current |
B | n | next-line |
BI | n | current |
BR | n | current |
DT | 0 | current |
I | n | next-line |
IB | n | current |
IR | n | current |
R | n | next-line |
RB | n | current |
RI | n | current |
SB | n | next-line |
SM | n | next-line |
TH | >1, <6 | current |
UC | <=1 | current |
br | 0 | current | compat
fi | 0 | current | compat
ft | 1 | current | compat
in | 1 | current | compat
na | 0 | current | compat
nf | 0 | current | compat
sp | 1 | current | compat

Macros marked as "compat" are included for compatibility with the significant corpus of existing manuals that mix dialects of roff. These macros should not be used for portable man manuals.

  Block Macros
Block macros comprise a head and body. As with in-line macros, the head is scoped to the current line and, in one circumstance, the next line (the next-line stipulations as in Line Macros apply here as well).

The syntax is as follows:

    .YO [head...]
    [head...]
    [body...]

The closure of body scope may be to the section, where a macro is closed by SH; sub-section, closed by a section or SS; part, closed by a section, sub-section, or RE; or paragraph, closed by a section, sub-section, part, HP, IP, LP, P, PP, or TP. No closure refers to an explicit block closing macro.

As a rule, block macros may not be nested; thus, calling a block macro while another block macro scope is open, and the open scope is not implicitly closed, is syntactically incorrect.

Macro | Arguments | Head Scope | Body Scope | Notes
HP | <2 | current | paragraph |
IP | <3 | current | paragraph |
LP | 0 | current | paragraph |
P | 0 | current | paragraph |
PP | 0 | current | paragraph |
RE | 0 | current | none | compat
RS | 1 | current | part | compat
SH | >0 | next-line | section |
SS | >0 | next-line | sub-section |
TP | n | next-line | paragraph |

Macros marked "compat" are as mentioned in Line Macros.

If a block macro is next-line scoped, it may only be followed by in-line macros for decorating text.

REFERENCE
This section is a canonical reference to all macros, arranged alphabetically. For the scoping of individual macros, see MACRO SYNTAX.

  AT
Sets the volume for the footer for compatibility with man pages from AT&T UNIX releases. The optional arguments specify which release it is from.

  B
Text is rendered in bold face.

See also I and R.

  BI
Text is rendered alternately in bold face and italic. Thus, ‘.BI this word and that’ causes ‘this’ and ‘and’ to render in bold face, while ‘word’ and ‘that’ render in italics. Whitespace between arguments is omitted in output.

Examples:

    .BI bold italic bold italic

The output of this example will be emboldened “bold” and italicised “italic”, with spaces stripped between arguments.

See also IB, BR, RB, RI, and IR.

  BR
Text is rendered alternately in bold face and roman (the default font). Whitespace between arguments is omitted in output.

See BI for an equivalent example.

See also BI, IB, RB, RI, and IR.

  DT
Has no effect. Included for compatibility.

  HP
Begin a paragraph whose initial output line is left-justified, but subsequent output lines are indented, with the following syntax:

.HP [width]

The width argument must conform to Scaling Widths. If specified, it's saved for later paragraph left-margins; if unspecified, the saved or default width is used.

See also IP, LP, P, PP, and TP.

  I
Text is rendered in italics.

See also B and R.

  IB
Text is rendered alternately in italics and bold face. Whitespace between arguments is omitted in output.

See BI for an equivalent example.

See also BI, BR, RB, RI, and IR.

  IP
Begin an indented paragraph with the following syntax:

.IP [head [width]]

The width argument defines the width of the left margin and is defined by Scaling Widths. It's saved for later paragraph left-margins; if unspecified, the saved or default width is used.

The head argument is used as a leading term, flushed to the left margin. This is useful for bulleted paragraphs and so on.

See also HP, LP, P, PP, and TP.

  IR
Text is rendered alternately in italics and roman (the default font). Whitespace between arguments is omitted in output.

See BI for an equivalent example.

See also BI, IB, BR, RB, and RI.

  LP
Begin an undecorated paragraph. The scope of a paragraph is closed by a subsequent paragraph, sub-section, section, or end of file. The saved paragraph left-margin width is reset to the default.

See also HP, IP, P, PP, and TP.

  P
Synonym for LP.

See also HP, IP, LP, PP, and TP.

  PP
Synonym for LP.

See also HP, IP, LP, P, and TP.

  R
Text is rendered in roman (the default font).

See also I and B.

  RB
Text is rendered alternately in roman (the default font) and bold face. Whitespace between arguments is omitted in output.

See BI for an equivalent example.

See also BI, IB, BR, RI, and IR.

  RE
Explicitly close out the scope of a prior RS.

  RI
Text is rendered alternately in roman (the default font) and italics. Whitespace between arguments is omitted in output.

See BI for an equivalent example.

See also BI, IB, BR, RB, and IR.

  RS
Begin a part setting the left margin. The left margin controls the offset, following an initial indentation, to un-indented text such as that of PP. This has the following syntax:

.Rs [width]

The width argument must conform to Scaling Widths. If not specified, the saved or default width is used.

  SB
Text is rendered in small size (one point smaller than the default font) bold face.

  SH
Begin a section. The scope of a section is only closed by another section or the end of file. The paragraph left-margin width is reset to the default.

  SM
Text is rendered in small size (one point smaller than the default font).

  SS
Begin a sub-section. The scope of a sub-section is closed by a subsequent sub-section, section, or end of file. The paragraph left-margin width is reset to the default.

  TH
Sets the title of the manual page with the following syntax:

.TH title section [date [source [volume]]]

At least the upper-case document title and the manual section arguments must be provided. The date argument should be formatted as described in Dates, but will be printed verbatim if it is not. If the date is not specified, the current date is used. The source string specifies the organisation providing the utility. The volume string replaces the default rendered volume, which is dictated by the manual section.

Examples:

    .TH CVS 5 1992-02-12 GNU

  TP
Begin a paragraph where the head, if exceeding the indentation width, is followed by a newline; if not, the body follows on the same line after a buffer to the indentation width. Subsequent output lines are indented. The syntax is as follows:

.TP [width]

The width argument must conform to Scaling Widths. If specified, it's saved for later paragraph left-margins; if unspecified, the saved or default width is used.

See also HP, IP, LP, P, and PP.

  UC
Sets the volume for the footer for compatibility with man pages from BSD releases. The optional first argument specifies which release it is from.

  br
Breaks the current line. Consecutive invocations have no further effect.

See also sp.

  fi
End literal mode begun by nf.

  ft
Change the current font mode. See Text Decoration for a listing of available font modes.

  in
Indent relative to the current indentation:

    .in [width]

If width is signed, the new offset is relative. Otherwise, it is absolute. This value is reset upon the next paragraph, section, or sub-section.

  na
Don't align to the right margin.

  nf
Begin literal mode: all subsequent free-form lines have their end of line boundaries preserved. May be ended by fi.

  sp
Insert vertical spaces into output with the following syntax:

.sp [height]

Insert height spaces, which must conform to Scaling Widths. If 0, this is equivalent to the br macro. Defaults to 1, if unspecified.

See also br.

COMPATIBILITY
This section documents areas of questionable portability between implementations of the man language.

-   In quoted literals, GNU troff allowed pair-wise double-quotes to produce a standalone double-quote in formatted output. It is not known whether this behaviour is exhibited by other formatters.
-   troff suppresses a newline before ‘'’ macro output; in mandoc, it is an alias for the standard ‘’. control character.
-   The ‘\h’ (horizontal position), ‘\v’ (vertical position), ‘\m’ (text colour), ‘\M’ (text filling colour), ‘\z’ (zero-length character), ‘\w’ (string length), ‘\k’ (horizontal position marker), ‘\o’ (text overstrike), and ‘\s’ (text size) escape sequences are all discarded in mandoc.
-   The ‘\f’ scaling unit is accepted by mandoc, but rendered as the default unit.
-   The sp macro does not accept negative values in mandoc. In GNU troff, this would result in strange behaviour.

SEE ALSO
man(1), mandoc(1), mandoc_char(7), mdoc(7), roff(7), tbl(7)

HISTORY
The man language first appeared as a macro package for the roff typesetting system in AT&T UNIX. It was later rewritten by James Clark as a macro package for groff. The stand-alone implementation that is part of the mandoc(1) utility written by Kristaps Dzonsons appeared in OpenBSD 4.6.

AUTHORS
This man reference was written by Kristaps Dzonsons <kristaps@bsd.lv>.

CAVEATS
Do not use this language. Use mdoc(7), instead.