Manual browser: mandoc(1)

MANDOC(1) General Commands Manual MANDOC(1)


mandocformat and display UNIX manuals


mandoc [-V] [-Ios=name] [-mformat] [-Ooption] [-Toutput] [-Wlevel] [file ...]


The mandoc utility formats UNIX manual pages for display.

By default, mandoc reads mdoc(7) or man(7) text from stdin, implying -mandoc, and produces -Tascii output.

The arguments are as follows:

Override the default operating system name for the mdoc(7) ‘Os’ macro.
Input format. See Input Formats for available formats. Defaults to -mandoc.
Comma-separated output options.
Output format. See Output Formats for available formats. Defaults to -Tascii.
Print version and exit.
Specify the minimum message level to be reported on the standard error output and to affect the exit status. The level can be warning, error, or fatal. The default is -Wfatal; -Wall is an alias for -Wwarning. See EXIT STATUS and DIAGNOSTICS for details.

The special option -Wstop tells mandoc to exit after parsing a file that causes warnings or errors of at least the requested level. No formatted output will be produced from that file. If both a level and stop are requested, they can be joined with a comma, for example -Werror,stop.

Read input from zero or more files. If unspecified, reads from stdin. If multiple files are specified, mandoc will halt with the first failed parse.

Input Formats

The mandoc utility accepts mdoc(7) and man(7) input with -mdoc and -man, respectively. The mdoc(7) format is strongly recommended; man(7) should only be used for legacy manuals.

A third option, -mandoc, which is also the default, determines encoding on-the-fly: if the first non-comment macro is ‘Dd’ or ‘Dt’, the mdoc(7) parser is used; otherwise, the man(7) parser is used.

If multiple files are specified with -mandoc, each has its file-type determined this way. If multiple files are specified and -mdoc or -man is specified, then this format is used exclusively.

Output Formats

The mandoc utility accepts the following -T arguments, which correspond to output modes:
Produce 7-bit ASCII output. This is the default. See ASCII Output.
Produce strict CSS1/HTML-4.01 output. See HTML Output.
Parse only: produce no output. Implies -Wwarning.
Encode output using the current locale. See Locale Output.
Produce man(7) format output. See Man Output.
Produce PDF output. See PDF Output.
Produce PostScript output. See PostScript Output.
Produce an indented parse tree.
Encode output in the UTF-8 multi-byte format. See UTF-8 Output.
Produce strict CSS1/XHTML-1.0 output. See XHTML Output.

If multiple input files are specified, these will be processed by the corresponding filter in-order.

ASCII Output

Output produced by -Tascii, which is the default, is rendered in standard 7-bit ASCII documented in ascii(7).

Font styles are applied by using back-spaced encoding such that an underlined character ‘c’ is rendered as ‘_\[bs]c’, where ‘\[bs]’ is the back-space character number 8. Emboldened characters are rendered as ‘c\[bs]c’.

The special characters documented in mandoc_char(7) are rendered best-effort in an ASCII equivalent. If no equivalent is found, ‘?’ is used instead.

Output width is limited to 78 visible columns unless literal input lines exceed this limit.

The following -O arguments are accepted:

The left margin for normal text is set to indent blank characters instead of the default of five for mdoc(7) and seven for man(7). Increasing this is not recommended; it may result in degraded formatting, for example overfull lines or ugly line breaks.
The output width is set to width, which will normalise to ≥60.

HTML Output

Output produced by -Thtml conforms to HTML-4.01 strict.

The file documents style-sheet classes available for customising output. If a style-sheet is not specified with -Ostyle, -Thtml defaults to simple output readable in any graphical or text-based web browser.

Special characters are rendered in decimal-encoded UTF-8.

The following -O arguments are accepted:

Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body> elements and only emit the subtree below the <body> element. The style argument will be ignored. This is useful when embedding manual content within existing documents.
The string fmt, for example, ../src/%I.html, is used as a template for linked header files (usually via the ‘In’ macro). Instances of ‘%I’ are replaced with the include filename. The default is not to present a hyperlink.
The string fmt, for example, ../html%S/%N.%S.html, is used as a template for linked manuals (usually via the ‘Xr’ macro). Instances of ‘%N’ and ‘%S’ are replaced with the linked manual's name and section, respectively. If no section is included, section 1 is assumed. The default is not to present a hyperlink.
The file style.css is used for an external style-sheet. This must be a valid absolute or relative URI.

Locale Output

Locale-depending output encoding is triggered with -Tlocale. This option is not available on all systems: systems without locale support, or those whose internal representation is not natively UCS-4, will fall back to -Tascii. See ASCII Output for font style specification and available command-line arguments.

Man Output

Translate input format into man(7) output format. This is useful for distributing manual sources to legacy systems lacking mdoc(7) formatters.

If mdoc(7) is passed as input, it is translated into man(7). If the input format is man(7), the input is copied to the output, expanding any roff(7) ‘so’ requests. The parser is also run, and as usual, the -W level controls which DIAGNOSTICS are displayed before copying the input to the output.

PDF Output

PDF-1.1 output may be generated by -Tpdf. See PostScript Output for -O arguments and defaults.

PostScript Output

PostScript “Adobe-3.0” Level-2 pages may be generated by -Tps. Output pages default to letter sized and are rendered in the Times font family, 11-point. Margins are calculated as 1/9 the page length and width. Line-height is 1.4m.

Special characters are rendered as in ASCII Output.

The following -O arguments are accepted:

The paper size name may be one of a3, a4, a5, legal, or letter. You may also manually specify dimensions as NNxNN, width by height in millimetres. If an unknown value is encountered, letter is used.

UTF-8 Output

Use -Tutf8 to force a UTF-8 locale. See Locale Output for details and options.

XHTML Output

Output produced by -Txhtml conforms to XHTML-1.0 strict.

See HTML Output for details; beyond generating XHTML tags instead of HTML tags, these output modes are identical.


The mandoc utility exits with one of the following values, controlled by the message level associated with the -W option:

No warnings or errors occurred, or those that did were ignored because they were lower than the requested level.
At least one warning occurred, but no error, and -Wwarning was specified.
At least one parsing error occurred, but no fatal error, and -Werror or -Wwarning was specified.
A fatal parsing error occurred.
Invalid command line arguments were specified. No input files have been read.
An operating system error occurred, for example memory exhaustion or an error accessing input files. Such errors cause mandoc to exit at once, possibly in the middle of parsing or formatting a file.

Note that selecting -Tlint output mode implies -Wwarning.


To page manuals to the terminal:

$ mandoc -Wall,stop mandoc.1 2>&1 | less
$ mandoc mandoc.1 mdoc.3 mdoc.7 | less

To produce HTML manuals with style.css as the style-sheet:

$ mandoc -Thtml -Ostyle=style.css mdoc.7 > mdoc.7.html

To check over a large set of manuals:

$ mandoc -Tlint `find /usr/src -name \*\.[1-9]`

To produce a series of PostScript manuals for A4 paper:

$ mandoc -Tps -Opaper=a4 mdoc.7 man.7 >

Convert a modern mdoc(7) manual to the older man(7) format, for use on systems lacking an mdoc(7) parser:

$ mandoc -Tman foo.mdoc >


Standard error messages reporting parsing errors are prefixed by

file:line:column: level:

where the fields have the following meanings:

The name of the input file causing the message.
The line number in that input file. Line numbering starts at 1.
The column number in that input file. Column numbering starts at 1. If the issue is caused by a word, the column number usually points to the first character of the word.
The message level, printed in capital letters.

Message levels have the following meanings:

The parser is unable to parse a given input file at all. No formatted output is produced from that input file.
An input file contains syntax that cannot be safely interpreted, either because it is invalid or because mandoc does not implement it yet. By discarding part of the input or inserting missing tokens, the parser is able to continue, and the error does not prevent generation of formatted output, but typically, preparing that output involves information loss, broken document structure or unintended formatting.
An input file uses obsolete, discouraged or non-portable syntax. All the same, the meaning of the input is unambiguous and a correct rendering can be produced. Documents causing warnings may render poorly when using other formatting tools instead of mandoc.

Messages of the warning and error levels are hidden unless their level, or a lower level, is requested using a -W option or -Tlint output mode.

The mandoc utility may also print messages related to invalid command line arguments or operating system errors, for example when memory is exhausted or input files cannot be read. Such messages do not carry the prefix described above.


This section summarises mandoc compatibility with GNU troff. Each input and output format is separately noted.

ASCII Compatibility

  • Unrenderable unicode codepoints specified with ‘\[uNNNN]’ escapes are printed as ‘?’ in mandoc. In GNU troff, these raise an error.
  • The ‘Bd -literal’ and ‘Bd -unfilled’ macros of mdoc(7) in -Tascii are synonyms, as are -filled and -ragged.
  • In historic GNU troff, the ‘Pa’ mdoc(7) macro does not underline when scoped under an ‘It’ in the FILES section. This behaves correctly in mandoc.
  • A list or display following the ‘Ss’ mdoc(7) macro in -Tascii does not assert a prior vertical break, just as it doesn't with ‘Sh’.
  • The ‘na’ man(7) macro in -Tascii has no effect.
  • Words aren't hyphenated.

HTML/XHTML Compatibility

  • The ‘\fP’ escape will revert the font to the previous ‘\f’ escape, not to the last rendered decoration, which is now dictated by CSS instead of hard-coded. It also will not span past the current scope, for the same reason. Note that in ASCII Output mode, this will work fine.
  • The mdoc(7) ‘Bl -hang’ and ‘Bl -tag’ list types render similarly (no break following overreached left-hand side) due to the expressive constraints of HTML.
  • The man(7) ‘IP’ and ‘TP’ lists render similarly.


The mandoc utility was written by Kristaps Dzonsons <>.


In -Thtml and -Txhtml, the maximum size of an element attribute is determined by BUFSIZ, which is usually 1024 bytes. Be aware of this when setting long link formats such as -Ostyle=really/long/link.

Nesting elements within next-line element scopes of -man, such as ‘br’ within an empty ‘B’, will confuse -Thtml and -Txhtml and cause them to forget the formatting of the prior next-line scope.

The ‘'’ control character is an alias for the standard macro control character and does not emit a line-break as stipulated in GNU troff.

July 13, 2013 NetBSD 7.0