-.\" $Id: mdoc.7,v 1.248 2015/01/03 00:59:13 schwarze Exp $
+.\" $Id: mdoc.7,v 1.270 2017/10/23 13:54:41 schwarze Exp $
.\"
.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
-.\" Copyright (c) 2010, 2011, 2013 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2010, 2011, 2013-2017 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
-.Dd $Mdocdate: January 3 2015 $
+.Dd $Mdocdate: October 23 2017 $
.Dt MDOC 7
.Os
.Sh NAME
\&.El
.Ed
.Pp
+List the options in alphabetical order,
+uppercase before lowercase for each letter and
+with no regard to whether an option takes an argument.
+Put digits in ascending order before all letter options.
+.Pp
Manuals not documenting a command won't include the above fragment.
.Pp
Since the
.It Sx \&Ap Ta apostrophe without surrounding whitespace (no arguments)
.It Sx \&Sm Ta switch horizontal spacing mode: Op Cm on | off
.It Sx \&Bk , \&Ek Ta keep block: Fl words
-.It Sx \&br Ta force output line break in text mode (no arguments)
-.It Sx \&sp Ta force vertical space: Op Ar height
.El
-.Ss Semantic markup for command line utilities:
+.Ss Semantic markup for command line utilities
.Bl -column "Brq, Bro, Brc" description
.It Sx \&Nm Ta start a SYNOPSIS block with the name of a utility
.It Sx \&Fl Ta command line options (flags) (>=0 arguments)
.It Sx \&Ev Ta environmental variable (>0 arguments)
.It Sx \&Pa Ta file system path (>=0 arguments)
.El
-.Ss Semantic markup for function libraries:
+.Ss Semantic markup for function libraries
.Bl -column "Brq, Bro, Brc" description
.It Sx \&Lb Ta function library (one argument)
.It Sx \&In Ta include file (one argument)
.It Sx \&Er Ta error constant (>0 arguments)
.It Sx \&Ev Ta environmental variable (>0 arguments)
.El
-.Ss Various semantic markup:
+.Ss Various semantic markup
.Bl -column "Brq, Bro, Brc" description
.It Sx \&An Ta author name (>0 arguments)
.It Sx \&Lk Ta hyperlink: Ar uri Op Ar name
.Ss \&Ao
Begin a block enclosed by angle brackets.
Does not have any head arguments.
-.Pp
-Examples:
-.Dl \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
-.Pp
-See also
-.Sx \&Aq .
+This macro is almost never useful.
+See
+.Sx \&Aq
+for more details.
.Ss \&Ap
Inserts an apostrophe without any surrounding whitespace.
This is generally used as a grammatical device when referring to the verb
.Dl \&.Fn execve \&Ap d
.Ss \&Aq
Encloses its arguments in angle brackets.
+The only important use case is for email addresses.
+See
+.Sx \&Mt
+for an example.
.Pp
-Examples:
-.Dl \&.Fl -key= \&Ns \&Aq \&Ar val
+Occasionally, it is used for names of characters and keys, for example:
+.Bd -literal -offset indent
+Press the
+\&.Aq escape
+key to ...
+.Ed
.Pp
-.Em Remarks :
-this macro is often abused for rendering URIs, which should instead use
+For URIs, use
.Sx \&Lk
+instead, and
+.Sx \&In
+for
+.Dq #include
+directives.
+Never wrap
+.Sx \&Ar
+in
+.Sx \&Aq .
+.Pp
+Since
+.Sx \&Aq
+usually renders with non-ASCII characters in non-ASCII output modes,
+do not use it where the ASCII characters
+.Sq <
+and
+.Sq >
+are required as syntax elements.
+Instead, use these characters directly in such cases, combining them
+with the macros
+.Sx \&Pf ,
+.Sx \&Ns ,
or
-.Sx \&Mt ,
-or to note pre-processor
-.Dq Li #include
-statements, which should use
-.Sx \&In .
+.Sx \&Eo
+as needed.
.Pp
See also
.Sx \&Ao .
.At .
.It Cm III
.At III .
-.It Cm V[.[1-4]]?
+.It Cm V | V.[1-4]
A version of
.At V .
.El
must be one of the following:
.Bl -tag -width 13n -offset indent
.It Fl centered
-Produce one output line from each input line, and centre-justify each line.
+Produce one output line from each input line, and center-justify each line.
Using this display type is not recommended; many
.Nm
implementations render it poorly.
.Cm right ,
which justifies to the right margin; or
.Cm center ,
-which aligns around an imagined centre axis.
+which aligns around an imagined center axis.
.It
A macro invocation, which selects a predefined width
associated with that macro.
A columnated list.
The
.Fl width
-argument has no effect; instead, each argument specifies the width
-of one column, using either the scaling width syntax described in
-.Xr roff 7
-or the string length of the argument.
+argument has no effect; instead, the string length of each argument
+specifies the width of one column.
If the first line of the body of a
.Fl column
list is not an
A function name.
Its syntax is as follows:
.Bd -ragged -offset indent
-.Pf \. Ns Sx \&Fn
+.Pf . Sx \&Fn
.Op Ar functype
.Ar funcname
.Op Oo Ar argtype Oc Ar argname
.Sx \&Ic
macro is used when referring to specific instructions.
.Ss \&In
-An
-.Dq include
-file.
+The name of an include file.
+This macro is most often used in section 2, 3, and 9 manual pages.
+.Pp
When invoked as the first macro on an input line in the
.Em SYNOPSIS
section, the argument is displayed in angle brackets
and preceded by
-.Dq #include ,
+.Qq #include ,
and a blank line is inserted in front if there is a preceding
function declaration.
-This is most often used in section 2, 3, and 9 manual pages.
+In other sections, it only encloses its argument in angle brackets
+and causes no line break.
.Pp
Examples:
.Dl \&.In sys/types.h
list is the most complicated.
Its syntax is as follows:
.Pp
-.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...
.D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...
+.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...
.Pp
The arguments consist of one or more lines of text and macros
representing a complete table line.
-Cells within the line are delimited by tabs or by the special
+Cells within the line are delimited by the special
.Sx \&Ta
-block macro.
+block macro or by literal tab characters.
+.Pp
+Using literal tabs is strongly discouraged because they are very
+hard to use correctly and
+.Nm
+code using them is very hard to read.
+In particular, a blank character is syntactically significant
+before and after the literal tab character.
+If a word precedes or follows the tab without an intervening blank,
+that word is never interpreted as a macro call, but always output
+literally.
+.Pp
The tab cell delimiter may only be used within the
.Sx \&It
line itself; on following lines, only the
.Sx \&Ta
-macro can be used to delimit cells, and
+macro can be used to delimit cells, and portability requires that
.Sx \&Ta
-is only recognised as a macro when called by other macros,
-not as the first macro on a line.
+is called by other macros: some parsers do not recognize it when
+it appears as the first macro on a line.
.Pp
Note that quoted strings may span tab-delimited cells on an
.Sx \&It
line.
For example,
.Pp
-.Dl .It \(dqcol1 ; <TAB> col2 ;\(dq \&;
+.Dl .It \(dqcol1 ,\& <TAB> col2 ,\(dq \&;
.Pp
-will preserve the semicolon whitespace except for the last.
+will preserve the whitespace before both commas,
+but not the whitespace before the semicolon.
.Pp
See also
.Sx \&Bl .
.Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
.Ss \&Nd
A one line description of the manual's content.
-This may only be invoked in the
-.Em SYNOPSIS
-section subsequent the
-.Sx \&Nm
-macro.
+This is the mandatory last macro of the
+.Em NAME
+section and not appropriate for other sections.
.Pp
Examples:
.Dl Pf . Sx \&Nd mdoc language reference
.Xr mandoc 1
uses its
.Fl Ios
-argument, or, if that isn't specified either,
+argument or, if that isn't specified either,
.Fa sysname
and
.Fa release
Close parenthesised context opened by
.Sx \&Po .
.Ss \&Pf
-Removes the space between its argument
-.Pq Dq prefix
-and the following macro.
+Removes the space between its argument and the following macro.
Its syntax is as follows:
.Pp
.D1 .Pf Ar prefix macro arguments ...
.Pp
This is equivalent to:
.Pp
-.D1 .No Ar prefix No \&Ns Ar macro arguments ...
+.D1 .No \e& Ns Ar prefix No \&Ns Ar macro arguments ...
+.Pp
+The
+.Ar prefix
+argument is not parsed for macro names or delimiters,
+but used verbatim as if it were escaped.
.Pp
Examples:
.Dl ".Pf $ Ar variable_name"
+.Dl ".Pf . Ar macro_name"
.Dl ".Pf 0x Ar hex_digits"
.Pp
See also
\&.%A J. D. Ullman
\&.%B Introduction to Automata Theory, Languages, and Computation
\&.%I Addison-Wesley
-\&.%C Reading, Massachusettes
+\&.%C Reading, Massachusetts
\&.%D 1979
\&.Re
.Ed
.br
This standard is also called
X/Open Portability Guide version 7.
-.Pp
-.It \-p1003.1-2013
-.St -p1003.1-2013
-.br
-This is the first Technical Corrigendum.
.El
.It Other standards
.Pp
.Pq Qq cross-reference .
Its syntax is as follows:
.Pp
-.D1 Pf \. Sx \&Xr Ar name Op section
+.D1 Pf \. Sx \&Xr Ar name section
.Pp
Cross reference the
.Ar name
and
.Ar section
-number of another man page;
-omitting the section number is rarely useful.
+number of another man page.
.Pp
Examples:
.Dl \&.Xr mandoc 1
.Dl \&.Xr mandoc 1 \&;
.Dl \&.Xr mandoc 1 \&Ns s behaviour
-.Ss \&br
-Emits a line-break.
-This macro should not be used; it is implemented for compatibility with
-historical manuals.
-.Pp
-Consider using
-.Sx \&Pp
-in the event of natural paragraph breaks.
-.Ss \&sp
-Emits vertical space.
-This macro should not be used; it is implemented for compatibility with
-historical manuals.
-Its syntax is as follows:
-.Pp
-.D1 Pf \. Sx \&sp Op Ar height
-.Pp
-The
-.Ar height
-argument is a scaling width as described in
-.Xr roff 7 .
-If unspecified,
-.Sx \&sp
-asserts a single vertical space.
.Sh MACRO SYNTAX
The syntax of a macro depends on its classification.
In this section,
.It Sx \&Ux Ta Yes Ta Yes Ta n
.It Sx \&Va Ta Yes Ta Yes Ta n
.It Sx \&Vt Ta Yes Ta Yes Ta >0
-.It Sx \&Xr Ta Yes Ta Yes Ta >0
-.It Sx \&br Ta \&No Ta \&No Ta 0
-.It Sx \&sp Ta \&No Ta \&No Ta 1
+.It Sx \&Xr Ta Yes Ta Yes Ta 2
.El
.Ss Delimiters
When a macro argument consists of one single input character
these delimiters are put before the macro scope,
and when the trailing arguments are closing delimiters,
these delimiters are put after the macro scope.
+Spacing is suppressed after opening delimiters
+and before closing delimiters.
For example,
.Pp
.D1 Pf \. \&Aq "( [ word ] ) ."
.D1 Fl a ( b | c \*(Ba d ) e
.Pp
This applies to both opening and closing delimiters,
-and also to the middle delimiter:
+and also to the middle delimiter, which does not suppress spacing:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It \&|
font escape sequences is never required.
.Sh COMPATIBILITY
This section provides an incomplete list of compatibility issues
-between mandoc and other troff implementations, at this time limited
-to GNU troff
+between mandoc and GNU troff
.Pq Qq groff .
-The term
-.Qq historic groff
-refers to groff versions before 1.17,
-which featured a significant update of the
-.Pa doc.tmac
-file.
-.Pp
-Heirloom troff, the other significant troff implementation accepting
-\-mdoc, is similar to historic groff.
.Pp
The following problematic behaviour is found in groff:
-.ds hist (Historic groff only.)
.Pp
.Bl -dash -compact
.It
-Display macros
-.Po
-.Sx \&Bd ,
-.Sx \&Dl ,
-and
-.Sx \&D1
-.Pc
-may not be nested.
-\*[hist]
-.It
-.Sx \&At
-with unknown arguments produces no output at all.
-\*[hist]
-Newer groff and mandoc print
-.Qq AT&T UNIX
-and the arguments.
-.It
-.Sx \&Bl Fl column
-does not recognise trailing punctuation characters when they immediately
-precede tabulator characters, but treats them as normal text and
-outputs a space before them.
-.It
-.Sx \&Bd Fl ragged compact
-does not start a new line.
-\*[hist]
-.It
.Sx \&Dd
with non-standard arguments behaves very strangely.
When there are three arguments, they are printed verbatim.
.Dq Epoch
is printed.
.It
-.Sx \&Fl
-does not print a dash for an empty argument.
-\*[hist]
-.It
-.Sx \&Fn
-does not start a new line unless invoked as the line macro in the
-.Em SYNOPSIS
-section.
-\*[hist]
-.It
-.Sx \&Fo
-with
-.Pf non- Sx \&Fa
-children causes inconsistent spacing between arguments.
-In mandoc, a single space is always inserted between arguments.
-.It
-.Sx \&Ft
-in the
-.Em SYNOPSIS
-causes inconsistent vertical spacing, depending on whether a prior
-.Sx \&Fn
-has been invoked.
-See
-.Sx \&Ft
-and
-.Sx \&Fn
-for the normalised behaviour in mandoc.
-.It
-.Sx \&In
-ignores additional arguments and is not treated specially in the
-.Em SYNOPSIS .
-\*[hist]
-.It
-.Sx \&It
-sometimes requires a
-.Fl nested
-flag.
-\*[hist]
-In new groff and mandoc, any list may be nested by default and
-.Fl enum
-lists will restart the sequence only for the sub-list.
-.It
-.Sx \&Li
-followed by a delimiter is incorrectly used in some manuals
-instead of properly quoting that character, which sometimes works with
-historic groff.
-.It
.Sx \&Lk
only accepts a single link-name argument; the remainder is misformatted.
.It
.Sx \&%C
is not implemented (up to and including groff-1.22.2).
.It
-Historic groff only allows up to eight or nine arguments per macro input
-line, depending on the exact situation.
-Providing more arguments causes garbled output.
-The number of arguments on one input line is not limited with mandoc.
-.It
-Historic groff has many un-callable macros.
-Most of these (excluding some block-level macros) are callable
-in new groff and mandoc.
-.It
-.Sq \(ba
-(vertical bar) is not fully supported as a delimiter.
-\*[hist]
-.It
.Sq \ef
.Pq font face
and
.Bl -dash -compact
.It
.Sx \&Bd
-.Fl file Ar file .
+.Fl file Ar file
+is unsupported for security reasons.
+.It
+.Sx \&Bd
+.Fl filled
+does not adjust the right margin, but is an alias for
+.Sx \&Bd
+.Fl ragged .
+.It
+.Sx \&Bd
+.Fl literal
+does not use a literal font, but is an alias for
+.Sx \&Bd
+.Fl unfilled .
.It
.Sx \&Bd
.Fl offset Cm center
and
-.Fl offset Cm right .
-Groff does not implement centred and flush-right rendering either,
+.Fl offset Cm right
+don't work.
+Groff does not implement centered and flush-right rendering either,
but produces large indentations.
.El
.Sh SEE ALSO
.Xr mandoc_char 7 ,
.Xr roff 7 ,
.Xr tbl 7
+.Pp
+The web page
+.Lk http://mandoc.bsd.lv/mdoc/ "extended documentation for the mdoc language"
+provides a few tutorial-style pages for beginners, an extensive style
+guide for advanced authors, and an alphabetic index helping to choose
+the best macros for various kinds of content.
.Sh HISTORY
The
.Nm
git.ckatri.com / mandoc.git / blobdiff