in apropos(1) output, sort names and avoid multiple section numbers

[mandoc.git] / roff.7

diff --git a/roff.7 b/roff.7
index 1967a1d766be549f10046cb45941ce0ad51d4771..49ad11ee0ab4d490e35563c7c165dbdecd5132db 100644 (file)
--- a/roff.7
+++ b/roff.7
@@ -1,7 +1,7 @@
-.\"    $Id: roff.7,v 1.22 2011/01/04 15:02:00 kristaps Exp $
+.\"    $Id: roff.7,v 1.49 2014/03/17 06:57:48 schwarze Exp $

 .\"
 .\"

-.\" Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
-.\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010, 2011, 2013, 2014 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
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above


@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" 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 4 2011 $
+.Dd $Mdocdate: March 17 2014 $

 .Dt ROFF 7
 .Os
 .Sh NAME
 .Dt ROFF 7
 .Os
 .Sh NAME


@@ -25,42 +25,291 @@
 The
 .Nm roff
 language is a general purpose text formatting language.
 The
 .Nm roff
 language is a general purpose text formatting language.

-In particular, it serves as the basis for the
+Since traditional implementations of the

 .Xr mdoc 7
 and
 .Xr man 7
 .Xr mdoc 7
 and
 .Xr man 7

-manual formatting macro languages.
-This manual describes the subset of the
+manual formatting languages are based on it,
+many real-world manuals use small numbers of

 .Nm
 .Nm

-language accepted by the
+requests and escape sequences intermixed with their
+.Xr mdoc 7
+or
+.Xr man 7
+code.
+To properly format such manuals, the
+.Xr mandoc 1
+utility supports a tiny subset of
+.Nm
+requests and escapes.
+Only these requests and escapes supported by

 .Xr mandoc 1
 .Xr mandoc 1

-utility.
+are documented in the present manual,
+together with the basic language syntax shared by
+.Nm ,
+.Xr mdoc 7 ,
+and
+.Xr man 7 .
+For complete
+.Nm
+manuals, consult the
+.Sx SEE ALSO
+section.

 .Pp
 .Pp

-Input lines beginning with the control characters
+Input lines beginning with the control character

 .Sq \&.
 .Sq \&.

-or
-.Sq \(aq

 are parsed for requests and macros.
 are parsed for requests and macros.

-These define the document structure, change the processing state
-and manipulate the formatting.
-Some requests and macros also produce formatted output,
-while others do not.
-.Pp
-All other input lines provide free-form text to be printed;
-the formatting of free-form text depends on the respective
-processing context.
+Such lines are called
+.Dq request lines
+or
+.Dq macro lines ,
+respectively.
+Requests change the processing state and manipulate the formatting;
+some macros also define the document structure and produce formatted
+output.
+The single quote
+.Pq Qq \(aq
+is accepted as an alternative control character,
+treated by
+.Xr mandoc 1
+just like
+.Ql \&.
+.Pp
+Lines not beginning with control characters are called
+.Dq text lines .
+They provide free-form text to be printed; the formatting of the text
+depends on the respective processing context.

 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space
 character, and, in certain circumstances, the tab character.
 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space
 character, and, in certain circumstances, the tab character.

-To produce other characters in the output, use the escape sequences
-documented in the
+The backslash character
+.Sq \e
+indicates the start of an escape sequence, used for example for
+.Sx Comments ,
+.Sx Special Characters ,
+.Sx Predefined Strings ,
+and
+user-defined strings defined using the
+.Sx ds
+request.
+For a listing of escape sequences, consult the
+.Sx ESCAPE SEQUENCE REFERENCE
+below.
+.Ss Comments
+Text following an escaped double-quote
+.Sq \e\(dq ,
+whether in a request, macro, or text line, is ignored to the end of the line.
+A request line beginning with a control character and comment escape
+.Sq \&.\e\(dq
+is also ignored.
+Furthermore, request lines with only a control character and optional
+trailing whitespace are stripped from input.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.\e\(dq This is a comment line.
+\&.\e\(dq The next line is ignored:
+\&.
+\&.Sh EXAMPLES \e\(dq This is a comment, too.
+\&example text \e\(dq And so is this.
+.Ed
+.Ss Special Characters
+Special characters are used to encode special glyphs and are rendered
+differently across output media.
+They may occur in request, macro, and text lines.
+Sequences begin with the escape character
+.Sq \e
+followed by either an open-parenthesis
+.Sq \&(
+for two-character sequences; an open-bracket
+.Sq \&[
+for n-character sequences (terminated at a close-bracket
+.Sq \&] ) ;
+or a single one character sequence.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \e(em
+Two-letter em dash escape.
+.It Li \ee
+One-letter backslash escape.
+.El
+.Pp
+See

 .Xr mandoc_char 7
 .Xr mandoc_char 7

-manual.
+for a complete list.
+.Ss Text Decoration
+Terms may be text-decorated using the
+.Sq \ef
+escape followed by an indicator: B (bold), I (italic), R (regular), or P
+(revert to previous mode).
+A numerical representation 3, 2, or 1 (bold, italic, and regular,
+respectively) may be used instead.
+The indicator or numerical representative may be preceded by C
+(constant-width), which is ignored.
+.Pp
+The two-character indicator
+.Sq BI
+requests a font that is both bold and italic.
+It may not be portable to old roff implementations.

 .Pp
 .Pp

-All manuals must have
-.Ux
-line terminators.
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \efBbold\efR
+Write in \fBbold\fP, then switch to regular font mode.
+.It Li \efIitalic\efP
+Write in \fIitalic\fP, then return to previous font mode.
+.It Li \ef(BIbold italic\efP
+Write in \f(BIbold italic\fP, then return to previous font mode.
+.El
+.Pp
+Text decoration is
+.Em not
+recommended for
+.Xr mdoc 7 ,
+which encourages semantic annotation.
+.Ss Predefined Strings
+Predefined strings, like
+.Sx Special Characters ,
+mark special output glyphs.
+Predefined strings are escaped with the slash-asterisk,
+.Sq \e* :
+single-character
+.Sq \e*X ,
+two-character
+.Sq \e*(XX ,
+and N-character
+.Sq \e*[N] .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \e*(Am
+Two-letter ampersand predefined string.
+.It Li \e*q
+One-letter double-quote predefined string.
+.El
+.Pp
+Predefined strings are not recommended for use,
+as they differ across implementations.
+Those supported by
+.Xr mandoc 1
+are listed in
+.Xr mandoc_char 7 .
+Manuals using these predefined strings are almost certainly not portable.
+.Ss Whitespace
+Whitespace consists of the space character.
+In text lines, whitespace is preserved within a line.
+In request and macro lines, whitespace delimits arguments and is discarded.
+.Pp
+Unescaped trailing spaces are stripped from text line input unless in a
+literal context.
+In general, trailing whitespace on any input line is discouraged for
+reasons of portability.
+In the rare case that a blank character is needed at the end of an
+input line, it may be forced by
+.Sq \e\ \e& .
+.Pp
+Literal space characters can be produced in the output
+using escape sequences.
+In macro lines, they can also be included in arguments using quotation; see
+.Sx MACRO SYNTAX
+for details.
+.Pp
+Blank text lines, which may include whitespace, are only permitted
+within literal contexts.
+If the first character of a text line is a space, that line is printed
+with a leading newline.
+.Ss Scaling Widths
+Many requests and macros support scaled widths for their arguments.
+The syntax for a scaled width is
+.Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
+where a decimal must be preceded or followed by at least one digit.
+Negative numbers, while accepted, are truncated to zero.
+.Pp
+The following scaling units are accepted:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It c
+centimetre
+.It i
+inch
+.It P
+pica (~1/6 inch)
+.It p
+point (~1/72 inch)
+.It f
+synonym for
+.Sq u
+.It v
+default vertical span
+.It m
+width of rendered
+.Sq m
+.Pq em
+character
+.It n
+width of rendered
+.Sq n
+.Pq en
+character
+.It u
+default horizontal span
+.It M
+mini-em (~1/100 em)
+.El
+.Pp
+Using anything other than
+.Sq m ,
+.Sq n ,
+.Sq u ,
+or
+.Sq v
+is necessarily non-portable across output media.
+See
+.Sx COMPATIBILITY .
+.Pp
+If a scaling unit is not provided, the numerical value is interpreted
+under the default rules of
+.Sq v
+for vertical spaces and
+.Sq u
+for horizontal ones.
+.Pp
+Examples:
+.Bl -tag -width ".Bl -tag -width 2i" -offset indent -compact
+.It Li \&.Bl -tag -width 2i
+two-inch tagged list indentation in
+.Xr mdoc 7
+.It Li \&.HP 2i
+two-inch tagged list indentation in
+.Xr man 7
+.It Li \&.sp 2v
+two vertical spaces
+.El
+.Ss Sentence Spacing
+Each sentence should terminate at the end of an input line.
+By doing this, a formatter 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
+.Po
+.Sq \&) ,
+.Sq \&] ,
+.Sq \&' ,
+.Sq \&"
+.Pc .
+.Pp
+The proper spacing is also intelligently preserved if a sentence ends at
+the boundary of a macro line.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+Do not end sentences mid-line like this.  Instead,
+end a sentence like this.
+A macro would end like this:
+\&.Xr mandoc 1 \&.
+.Ed

 .Sh REQUEST SYNTAX
 A request or macro line consists of:
 .Pp
 .Sh REQUEST SYNTAX
 A request or macro line consists of:
 .Pp


@@ -86,11 +335,66 @@ Thus, the following request lines are all equivalent:
 \&.ig    end
 \&.   ig end
 .Ed
 \&.ig    end
 \&.   ig end
 .Ed

+.Sh MACRO SYNTAX
+Macros are provided by the
+.Xr mdoc 7
+and
+.Xr man 7
+languages and can be defined by the
+.Sx \&de
+request.
+When called, they follow the same syntax as requests, except that
+macro arguments may optionally be quoted by enclosing them
+in double quote characters
+.Pq Sq \(dq .
+Quoted text, even if it contains whitespace or would cause
+a macro invocation when unquoted, is always considered literal text.
+Inside quoted text, pairs of double quote characters
+.Pq Sq Qq
+resolve to single double quote characters.
+.Pp
+To be recognised as the beginning of a quoted argument, the opening
+quote character must be preceded by a space character.
+A quoted argument extends to the next double quote character that is not
+part of a pair, or to the end of the input line, whichever comes earlier.
+Leaving out the terminating double quote character at the end of the line
+is discouraged.
+For clarity, if more arguments follow on the same input line,
+it is recommended to follow the terminating double quote character
+by a space character; in case the next character after the terminating
+double quote character is anything else, it is regarded as the beginning
+of the next, unquoted argument.
+.Pp
+Both in quoted and unquoted arguments, pairs of backslashes
+.Pq Sq \e\e
+resolve to single backslashes.
+In unquoted arguments, space characters can alternatively be included
+by preceding them with a backslash
+.Pq Sq \e\~ ,
+but quoting is usually better for clarity.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li .Fn strlen \(dqconst char *s\(dq
+Group arguments
+.Qq const char *s
+into one function argument.
+If unspecified,
+.Qq const ,
+.Qq char ,
+and
+.Qq *s
+would be considered separate arguments.
+.It Li .Op \(dqFl a\(dq
+Consider
+.Qq \&Fl a
+as literal text instead of a flag macro.
+.El

 .Sh REQUEST REFERENCE
 The
 .Xr mandoc 1
 .Nm
 .Sh REQUEST REFERENCE
 The
 .Xr mandoc 1
 .Nm

-parser recognizes the following requests.
+parser recognises the following requests.

 Note that the
 .Nm
 language defines many more requests not implemented in
 Note that the
 .Nm
 language defines many more requests not implemented in


@@ -98,7 +402,7 @@ language defines many more requests not implemented in
 .Ss \&ad
 Set line adjustment mode.
 This line-scoped request is intended to have one argument to select
 .Ss \&ad
 Set line adjustment mode.
 This line-scoped request is intended to have one argument to select

-normal, left, right, or center adjustment for subsequent text.
+normal, left, right, or centre adjustment for subsequent text.

 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 .Ss \&am
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 .Ss \&am


@@ -123,6 +427,30 @@ The syntax of this request is the same as that of
 It is currently ignored by
 .Xr mandoc 1 ,
 as are its children.
 It is currently ignored by
 .Xr mandoc 1 ,
 as are its children.

+.Ss \&as
+Append to a user-defined string.
+The syntax of this request is the same as that of
+.Sx \&ds .
+If a user-defined string with the specified name does not yet exist,
+it is set to the empty string before appending.
+.Ss \&cc
+Changes the control character.
+Its syntax is as follows:
+.Bd -literal -offset indent
+.Pf . Cm \&cc Op Ar c
+.Ed
+.Pp
+If
+.Ar c
+is not specified, the control character is reset to
+.Sq \&. .
+Trailing characters are ignored.
+.Ss \&ce
+Center some lines.
+This line-scoped request is intended to take one integer argument,
+specifying how many lines to center.
+Currently, it is ignored including its arguments, and the number
+of arguments is not checked.

 .Ss \&de
 Define a
 .Nm
 .Ss \&de
 Define a
 .Nm


@@ -174,12 +502,9 @@ The macro can be invoked later using the syntax
 .Pp
 .D1 Pf . Ar name Op Ar argument Op Ar argument ...
 .Pp
 .Pp
 .D1 Pf . Ar name Op Ar argument Op Ar argument ...
 .Pp

-Arguments are separated by blank characters and can be quoted
-using double-quotes
-.Pq Sq \(dq
-to allow inclusion of blank characters into arguments.
-To include the double-quote character into a quoted argument,
-escape it from ending the argument by doubling it.
+Regarding argument parsing, see
+.Sx MACRO SYNTAX
+above.

 .Pp
 The line invoking the macro will be replaced
 in the input stream by the
 .Pp
 The line invoking the macro will be replaced
 in the input stream by the


@@ -319,6 +644,52 @@ then false is assumed.
 The syntax of this request is similar to
 .Sx \&if
 except that the conditional is missing.
 The syntax of this request is similar to
 .Sx \&if
 except that the conditional is missing.

+.Ss \&EN
+End an equation block.
+See
+.Sx \&EQ .
+.Ss \&EQ
+Begin an equation block.
+See
+.Xr eqn 7
+for a description of the equation language.
+.Ss \&fam
+Change the font family.
+This line-scoped request is intended to have one argument specifying
+the font family to be selected.
+It is a groff extension, and currently, it is ignored including its
+arguments, and the number of arguments is not checked.
+.Ss \&ft
+Change the font.
+Its syntax is as follows:
+.Pp
+.D1 Pf . Cm \&ft Op Ar font
+.Pp
+The following
+.Ar font
+arguments are supported:
+.Bl -tag -width 4n -offset indent
+.It Cm B , BI , 3 , 4
+switches to
+.Sy bold
+font
+.It Cm I , 2
+switches to
+.Em underlined
+font
+.It Cm R , CW , 1
+switches to normal font
+.It Cm P No "or no argument"
+switches back to the previous font
+.El
+.Pp
+This request takes effect only locally, may be overridden by macros
+and escape sequences, and is only supported in
+.Xr man 7
+for now.
+.Ss \&hw
+Specify hyphenation points in words.
+This line-scoped request is currently ignored.

 .Ss \&hy
 Set automatic hyphenation mode.
 This line-scoped request is currently ignored.
 .Ss \&hy
 Set automatic hyphenation mode.
 This line-scoped request is currently ignored.


@@ -334,10 +705,73 @@ Its syntax is equivalent to
 .Sx \&if .
 .Ss \&if
 Begins a conditional.
 .Sx \&if .
 .Ss \&if
 Begins a conditional.

-Right now, the conditional evaluates to true
-if and only if it starts with the letter
-.Sy n ,
-indicating processing in nroff style as opposed to troff style.
+This request has the following syntax:
+.Bd -literal -offset indent
+\&.if COND BODY
+.Ed
+.Bd -literal -offset indent
+\&.if COND \e{BODY
+BODY...\e}
+.Ed
+.Bd -literal -offset indent
+\&.if COND \e{\e
+BODY...
+\&.\e}
+.Ed
+.Pp
+COND is a conditional statement.
+Currently,
+.Xr mandoc 1
+supports the following subset of roff conditionals:
+.Bl -bullet
+.It
+If
+.Sq \&!
+is prefixed to COND, the condition is logically inverted.
+.It
+If the first character of COND is
+.Sq n
+.Pq nroff mode
+or
+.Sq o
+.Pq odd page ,
+COND evaluates to true.
+.It
+If the first character of COND is
+.Sq c
+.Pq character available ,
+.Sq d
+.Pq string defined ,
+.Sq e
+.Pq even page ,
+.Sq r
+.Pq register accessed ,
+or
+.Sq t
+.Pq troff mode ,
+COND evaluates to false.
+.It
+If COND starts with a digit, optionally prefixed by a minus sign,
+it is evaluated as a numerical expression of the form
+.Ar number operator number ,
+where
+.Ar operator
+is one of
+.Sq < ,
+.Sq <= ,
+.Sq = ,
+.Sq >= ,
+or
+.Sq > .
+.It
+Otherwise, the first character of COND is regarded as a delimiter
+and COND evaluates to true if the string extending from its first
+to its second occurrence is equal to the string extending from its
+second to its third occurrence.
+.It
+If COND cannot be parsed, it evaluates to false.
+.El
+.Pp

 If a conditional is false, its children are not processed, but are
 syntactically interpreted to preserve the integrity of the input
 document.
 If a conditional is false, its children are not processed, but are
 syntactically interpreted to preserve the integrity of the input
 document.


@@ -355,44 +789,12 @@ will continue to syntactically interpret to the block close of the final
 conditional.
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.
 conditional.
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.

-This request has the following syntax:
-.Bd -literal -offset indent
-\&.if COND \e{\e
-BODY...
-\&.\e}
-.Ed
-.Bd -literal -offset indent
-\&.if COND \e{ BODY
-BODY... \e}
-.Ed
-.Bd -literal -offset indent
-\&.if COND \e{ BODY
-BODY...
-\&.\e}
-.Ed
-.Bd -literal -offset indent
-\&.if COND \e
-BODY
-.Ed
-.Pp
-COND is a conditional statement.
-roff allows for complicated conditionals; mandoc is much simpler.
-At this time, mandoc supports only
-.Sq n ,
-evaluating to true;
-and
-.Sq t ,
-.Sq e ,
-and
-.Sq o ,
-evaluating to false.
-All other invocations are read up to the next end of line or space and
-evaluate as false.

 .Pp
 If the BODY section is begun by an escaped brace
 .Sq \e{ ,
 .Pp
 If the BODY section is begun by an escaped brace
 .Sq \e{ ,

-scope continues until a closing-brace escape sequence
-.Sq \.\e} .
+scope continues until the end of the input line containing the
+matching closing-brace escape sequence
+.Sq \e} .

 If the BODY is not enclosed in braces, scope continues until
 the end of the line.
 If the COND is followed by a BODY on the same line, whether after a
 If the BODY is not enclosed in braces, scope continues until
 the end of the line.
 If the COND is followed by a BODY on the same line, whether after a


@@ -414,15 +816,20 @@ than having the request or macro follow as
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.
 .Pp
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.
 .Pp

-Note that text following an
-.Sq \&.\e}
-escape sequence is discarded.
-Furthermore, if an explicit closing sequence
+Note that the

 .Sq \e}
 .Sq \e}

-is specified in a free-form line, the entire line is accepted within the
-scope of the prior request, not only the text preceding the close, with the
+is converted into a zero-width escape sequence if not passed as a
+standalone macro
+.Sq \&.\e} .
+For example,
+.Pp
+.D1 \&.Fl a \e} b
+.Pp
+will result in

 .Sq \e}
 .Sq \e}

-collapsing into a zero-width space.
+being considered an argument of the
+.Sq \&Fl
+macro.

 .Ss \&ig
 Ignore input.
 Its syntax can be either
 .Ss \&ig
 Ignore input.
 Its syntax can be either


@@ -481,19 +888,22 @@ the name of the request, macro or string to be undefined.
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 .Ss \&nr
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 .Ss \&nr

-Define a register.
+Define or change a register.

 A register is an arbitrary string value that defines some sort of state,
 which influences parsing and/or formatting.
 Its syntax is as follows:
 .Pp
 A register is an arbitrary string value that defines some sort of state,
 which influences parsing and/or formatting.
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Cm \&nr Ar name Ar value
+.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar value

 .Pp
 The
 .Ar value
 may, at the moment, only be an integer.
 .Pp
 The
 .Ar value
 may, at the moment, only be an integer.

-So far, only the following register
+If it is prefixed by a sign, the register will be
+incremented or decremented instead of assigned to.
+.Pp
+The following register

 .Ar name
 .Ar name

-is recognised:
+is handled specially:

 .Bl -tag -width Ds
 .It Cm nS
 If set to a positive integer value, certain
 .Bl -tag -width Ds
 .It Cm nS
 If set to a positive integer value, certain


@@ -512,6 +922,16 @@ section with the
 .Cm \&Sh
 macro will reset this register.
 .El
 .Cm \&Sh
 macro will reset this register.
 .El

+.Ss \&ns
+Turn on no-space mode.
+This line-scoped request is intended to take no arguments.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.
+.Ss \&ps
+Change point size.
+This line-scoped request is intended to take one numerical argument.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.

 .Ss \&so
 Include a source file.
 Its syntax is as follows:
 .Ss \&so
 Include a source file.
 Its syntax is as follows:


@@ -523,18 +943,49 @@ The
 will be read and its contents processed as input in place of the
 .Sq \&.so
 request line.
 will be read and its contents processed as input in place of the
 .Sq \&.so
 request line.

-To avoid inadvertant inclusion of unrelated files,
+To avoid inadvertent inclusion of unrelated files,

 .Xr mandoc 1
 only accepts relative paths not containing the strings
 .Qq ../
 and
 .Qq /.. .
 .Xr mandoc 1
 only accepts relative paths not containing the strings
 .Qq ../
 and
 .Qq /.. .

+.Pp
+This request requires
+.Xr man 1
+to change to the right directory before calling
+.Xr mandoc 1 ,
+per convention to the root of the manual tree.
+Typical usage looks like:
+.Pp
+.Dl \&.so man3/Xcursor.3
+.Pp
+As the whole concept is rather fragile, the use of
+.Sx \&so
+is discouraged.
+Use
+.Xr ln 1
+instead.
+.Ss \&ta
+Set tab stops.
+This line-scoped request can take an arbitrary number of arguments.
+Currently, it is ignored including its arguments.

 .Ss \&tr
 Output character translation.
 .Ss \&tr
 Output character translation.

-This request is intended to have one argument,
-consisting of an even number of characters.
-Currently, it is ignored including its arguments,
-and the number of arguments is not checked.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Cm \&tr Ar [ab]+
+.Pp
+Pairs of
+.Ar ab
+characters are replaced
+.Ar ( a
+for
+.Ar b ) .
+Replacement (or origin) characters may also be character escapes; thus,
+.Pp
+.Dl tr \e(xx\e(yy
+.Pp
+replaces all invocations of \e(xx with \e(yy.

 .Ss \&T&
 Re-start a table layout, retaining the options of the prior table
 invocation.
 .Ss \&T&
 Re-start a table layout, retaining the options of the prior table
 invocation.


@@ -546,203 +997,254 @@ See
 .Sx \&TS .
 .Ss \&TS
 Begin a table, which formats input in aligned rows and columns.
 .Sx \&TS .
 .Ss \&TS
 Begin a table, which formats input in aligned rows and columns.

-A table consists of an optional single line of table options terminated
-by a semicolon, followed by one or more lines of layout specification
-terminated by a period, then table data.
-A table block may also include
-.Nm ,
-.Xr mdoc 7 ,
-or
-.Xr man 7
-macros.
-Example:
-.Bd -literal -offset indent
-\&.TS
-box tab(:);   \e" Table-wide options.
-c | c         \e" Layout for first line.
-| c | c.      \e" Layout for all subsequent lines.
-1:2           \e" Data...
-3:4
-\&.TE
-.Ed
-.Pp
-Table data is
-.Em pre-processed ,
-that is, data rows are parsed then inserted into the underlying stream
-of input data.
-This allows data rows to be interspersed by arbitrary macros, such as
-.Bd -literal -offset indent
-\&.TS
-tab(:);
-c c c.
-1:2:3
-\&.Ao
-3:2:1
-\&.Ac
-\&.TE
-.Ed
-.Pp
-in the case of
+See
+.Xr tbl 7
+for a description of the tbl language.
+.Sh ESCAPE SEQUENCE REFERENCE
+The
+.Xr mandoc 1
+.Nm
+parser recognises the following escape sequences.
+Note that the
+.Nm
+language defines more escape sequences not implemented in
+.Xr mandoc 1 .
+In

 .Xr mdoc 7
 .Xr mdoc 7

-or
-.Bd -literal -offset indent
-\&.TS
-tab(:);
-c c c.
-\&.ds ab 2
-1:\e*(ab:3
-\&.I
-3:2:1
-\&.TE
-.Ed
-.Pp
-in the case of
-.Xr man 7 .
+and
+.Xr man 7
+documents, using escape sequences is discouraged except for those
+described in the
+.Sx LANGUAGE SYNTAX
+section above.

 .Pp
 .Pp

-The first line of a table consists of its options, which consists of
-space-separated keys and modifiers terminated by a semicolon.
-If the first line does not have a terminating semicolon, it is assumed
-that no options are specified and instead a layout is processed.
-Some options accept arguments enclosed by paranthesis.
-The following case-insensitive options are available:
-.Bl -tag -width Ds
-.It Cm center
-This option is not supported by
-.Xr mandoc 1 .
-This may also be invoked with
-.Cm centre .
-.It Cm delim
-Accepts a two-character argument.
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm expand
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm box
-Draw a single-line box around the table.
-This may also be invoked with
-.Cm frame .
-.It Cm doublebox
-Draw a double-line box around the table.
-This may also be invoked with
-.Cm doubleframe .
-.It Cm allbox
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm tab
-Accepts a single-character argument.
-This character is used a delimiter between data cells, which otherwise
-defaults to the tab character.
-.It Cm linesize
-Accepts a natural number (all digits).
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm nokeep
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm decimalpoint
-Accepts a single-character argument.
-This character will be used as the decimal point with the
-.Cm n
-layout key.
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm nospaces
-This option is not supported by
+A backslash followed by any character not listed here
+simply prints that character itself.
+.Ss \e<newline>
+A backslash at the end of an input line can be used to continue the
+logical input line on the next physical input line, joining the text
+on both lines together as if it were on a single input line.
+.Ss \e<space>
+The escape sequence backslash-space
+.Pq Sq \e\ \&
+is an unpaddable space-sized non-breaking space character; see
+.Sx Whitespace .
+.Ss \e\(dq
+The rest of the input line is treated as
+.Sx Comments .
+.Ss \e%
+Hyphenation allowed at this point of the word; ignored by

 .Xr mandoc 1 .
 .Xr mandoc 1 .

-.El
-.Pp
-The table layout follows table options, except in the case of
-.Sx \&T& ,
-where it immediately procedes invocation.
-Layout specifies how data rows are displayed on output.
-Each layout line corresponds to a line of data; the last layout line
-applies to all remaining data lines.
-Layout lines may also be separated by a comma.
-Each layout cell consists of one of the following case-insensitive keys:
-.Bl -tag -width Ds
-.It Cm c
-Centre a literal string within its column.
-.It Cm r
-Right-justify a literal string within its column.
-.It Cm l
-Left-justify a literal string within its column.
-.It Cm n
-Justify a number around its decimal point.
-If the decimal point is not found on the number, it's assumed to trail
-the number.
-.It Cm s
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm a
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm ^
-This option is not supported by
-.Xr mandoc 1 .
-.It Cm \-
-Replace the data cell (its contents will be lost) with a single
-horizontal line.
-This may also be invoked with
-.Cm _ .
-.It Cm =
-Replace the data cell (its contents will be lost) with a double
-horizontal line.
-.It Cm \(ba
-Emit a vertical bar instead of data.
-.It Cm \(ba\(ba
-Emit a double-vertical bar instead of data.
-.El
-.Pp
-For example, following layout specifies a centre-justified column of
-minimum width 10, followed by vertical bar, followed by a left-justified
-column of minimum width 10, another vertical bar, then a column
-justified about the decimal point in numbers:
-.Pp
-.Dl c10 | l10 | n
-.Pp
-Keys may be followed by a set of modifiers.
-A modifier is either a modifier key or a natural number for specifying
-spacing.
-The following case-insensitive modifier keys are available:
-.Cm z ,
-.Cm u ,
-.Cm e ,
-.Cm t ,
-.Cm d ,
-.Cm f ,
-.Cm b ,
-.Cm i ,
-.Cm b ,
+.Ss \e&
+Non-printing zero-width character; see
+.Sx Whitespace .
+.Ss \e\(aq
+Acute accent special character; use
+.Sq \e(aa
+instead.
+.Ss \e( Ns Ar cc
+.Sx Special Characters
+with two-letter names, see
+.Xr mandoc_char 7 .
+.Ss \e*[ Ns Ar name ]
+Interpolate the string with the
+.Ar name ;
+see
+.Sx Predefined Strings
+and
+.Sx ds .
+For short names, there are variants
+.No \e* Ns Ar c

 and
 and

-.Cm i .
-All of these are ignored by
+.No \e*( Ns Ar cc .
+.Ss \e-
+Special character
+.Dq mathematical minus sign .
+.Ss \e[ Ns Ar name ]
+.Sx Special Characters
+with names of arbitrary length, see
+.Xr mandoc_char 7 .
+.Ss \e^
+One-twelfth em half-narrow space character, effectively zero-width in

 .Xr mandoc 1 .
 .Xr mandoc 1 .

-.Pp
-The data section follows the last layout row.
-By default, cells in a data section are delimited by a tab.
-This behaviour may be changed with the
-.Cm tab
-option.
-If
-.Cm _
-or
-.Cm =
-is specified, a single or double line, respectively, is drawn across the
-data field.
-If
-.Cm \e-
-or
-.Cm \e=
-is specified, a line is drawn within the data field (i.e., terminating
-within the cell and not draw to the border).
-If the last cell of a line is
-.Cm T{ ,
-all subsequent lines are included as part of the cell until
-.Cm T}
-is specified on its own line.
+.Ss \e`
+Grave accent special character; use
+.Sq \e(ga
+instead.
+.Ss \e{
+Begin conditional input; see
+.Sx if .
+.Ss \e\(ba
+One-sixth em narrow space character, effectively zero-width in
+.Xr mandoc 1 .
+.Ss \e}
+End conditional input; see
+.Sx if .
+.Ss \e~
+Paddable non-breaking space character.
+.Ss \e0
+Digit width space character.
+.Ss \eA\(aq Ns Ar string Ns \(aq
+Anchor definition; ignored by
+.Xr mandoc 1 .
+.Ss \eB\(aq Ns Ar string Ns \(aq
+Test whether
+.Ar string
+is a numerical expession; ignored by
+.Xr mandoc 1 .
+.Ss \eb\(aq Ns Ar string Ns \(aq
+Bracket building function; ignored by
+.Xr mandoc 1 .
+.Ss \eC\(aq Ns Ar name Ns \(aq
+.Sx Special Characters
+with names of arbitrary length.
+.Ss \ec
+Interrupt text processing to insert requests or macros; ignored by
+.Xr mandoc 1 .
+.Ss \eD\(aq Ns Ar string Ns \(aq
+Draw graphics function; ignored by
+.Xr mandoc 1 .
+.Ss \ed
+Move down by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \ee
+Backslash special character.
+.Ss \eF[ Ns Ar name ]
+Switch font family (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eF Ns Ar c
+and
+.No \eF( Ns Ar cc .
+.Ss \ef[ Ns Ar name ]
+Switch to the font
+.Ar name ,
+see
+.Sx Text Decoration .
+For short names, there are variants
+.No \ef Ns Ar c
+and
+.No \ef( Ns Ar cc .
+.Ss \eg[ Ns Ar name ]
+Interpolate the format of a number register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eg Ns Ar c
+and
+.No \eg( Ns Ar cc .
+.Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
+Set the height of the current font; ignored by
+.Xr mandoc 1 .
+.Ss \eh\(aq Ns Ar number Ns \(aq
+Horizontal motion; ignored by
+.Xr mandoc 1 .
+.Ss \ek[ Ns Ar name ]
+Mark horizontal input place in register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \ek Ns Ar c
+and
+.No \ek( Ns Ar cc .
+.Ss \eL\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
+Vertical line drawing function; ignored by
+.Xr mandoc 1 .
+.Ss \el\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
+Horizontal line drawing function; ignored by
+.Xr mandoc 1 .
+.Ss \eM[ Ns Ar name ]
+Set fill (background) color (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eM Ns Ar c
+and
+.No \eM( Ns Ar cc .
+.Ss \em[ Ns Ar name ]
+Set glyph drawing color (groff extension); ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \em Ns Ar c
+and
+.No \em( Ns Ar cc .
+.Ss \eN\(aq Ns Ar number Ns \(aq
+Character
+.Ar number
+on the current font.
+.Ss \en[ Ns Ar name ]
+Interpolate the number register
+.Ar name .
+For short names, there are variants
+.No \en Ns Ar c
+and
+.No \en( Ns Ar cc .
+.Ss \eo\(aq Ns Ar string Ns \(aq
+Overstrike
+.Ar string ;
+ignored by
+.Xr mandoc 1 .
+.Ss \eR\(aq Ns Ar name Oo +|- Oc Ns Ar number Ns \(aq
+Set number register; ignored by
+.Xr mandoc 1 .
+.Ss \eS\(aq Ns Ar number Ns \(aq
+Slant output; ignored by
+.Xr mandoc 1 .
+.Ss \es\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
+Change point size; ignored by
+.Xr mandoc 1 .
+Alternative forms
+.No \es Ns Oo +|- Oc Ns Ar n ,
+.No \es Ns Oo +|- Oc Ns \(aq Ns Ar number Ns \(aq ,
+.No \es Ns [ Oo +|- Oc Ns Ar number ] ,
+and
+.No \es Ns Oo +|- Oc Ns [ Ar number Ns ]
+are also parsed and ignored.
+.Ss \et
+Horizontal tab; ignored by
+.Xr mandoc 1 .
+.Ss \eu
+Move up by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \eV[ Ns Ar name ]
+Interpolate an environment variable; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eV Ns Ar c
+and
+.No \eV( Ns Ar cc .
+.Ss \ev\(aq Ns Ar number Ns \(aq
+Vertical motion; ignored by
+.Xr mandoc 1 .
+.Ss \ew\(aq Ns Ar string Ns \(aq
+Interpolate the width of the
+.Ar string ;
+ignored by
+.Xr mandoc 1 .
+.Ss \eX\(aq Ns Ar string Ns \(aq
+Output
+.Ar string
+as device control function; ignored in nroff mode and by
+.Xr mandoc 1 .
+.Ss \ex\(aq Ns Ar number Ns \(aq
+Extra line space function; ignored by
+.Xr mandoc 1 .
+.Ss \eY[ Ns Ar name ]
+Output a string as a device control function; ignored in nroff mode and by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eY Ns Ar c
+and
+.No \eY( Ns Ar cc .
+.Ss \eZ\(aq Ns Ar string Ns \(aq
+Print
+.Ar string
+with zero width and height; ignored by
+.Xr mandoc 1 .
+.Ss \ez
+Output the next character without advancing the cursor position;
+approximated in
+.Xr mandoc 1
+by simply skipping the next character.

 .Sh COMPATIBILITY
 .Sh COMPATIBILITY

-This section documents compatibility between mandoc and other other
+This section documents compatibility between mandoc and other

 .Nm
 implementations, at this time limited to GNU troff
 .Pq Qq groff .
 .Nm
 implementations, at this time limited to GNU troff
 .Pq Qq groff .


@@ -752,6 +1254,19 @@ refers to groff version 1.15.
 .Pp
 .Bl -dash -compact
 .It
 .Pp
 .Bl -dash -compact
 .It

+In mandoc, the
+.Sx \&EQ ,
+.Sx \&TE ,
+.Sx \&TS ,
+and
+.Sx \&T& ,
+macros are considered regular macros.
+In all other
+.Nm
+implementations, these are special macros that must be specified without
+spacing between the control character (which must be a period) and the
+macro name.
+.It

 The
 .Cm nS
 register is only compatible with OpenBSD's groff-1.15.
 The
 .Cm nS
 register is only compatible with OpenBSD's groff-1.15.


@@ -769,15 +1284,11 @@ using the next-line syntax.
 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,

+.Xr eqn 7 ,

 .Xr man 7 ,
 .Xr mandoc_char 7 ,
 .Xr man 7 ,
 .Xr mandoc_char 7 ,

-.Xr mdoc 7
-.Rs
-.%A M. E. Lesk
-.%T Tbl\(emA Program to Format Tables
-.%D June 11, 1976
-.%U http://www.kohala.com/start/troff/v7/man/tbl/tbl.ps
-.Re
+.Xr mdoc 7 ,
+.Xr tbl 7

 .Rs
 .%A Joseph F. Ossanna
 .%A Brian W. Kernighan
 .Rs
 .%A Joseph F. Ossanna
 .%A Brian W. Kernighan


@@ -798,19 +1309,27 @@ using the next-line syntax.
 .%U http://heirloom.sourceforge.net/doctools/troff.pdf
 .Re
 .Sh HISTORY
 .%U http://heirloom.sourceforge.net/doctools/troff.pdf
 .Re
 .Sh HISTORY

-The RUNOFF typesetting system was written in PL/1 for the CTSS
-operating system by Jerome ("Jerry") E. Saltzer in 1961.
-It was first used as the main documentation tool by Multics since 1963.
-Robert ("Bob") H. Morris ported it to the GE-635 and called it
+The RUNOFF typesetting system, whose input forms the basis for

 .Nm ,
 .Nm ,

-Doug McIlroy rewrote it in BCPL in 1969,
-Joseph F. Ossanna rewrote it in PDP-11 assembly in 1973,
-and Brian W. Kernighan rewrote it in C in 1975.
+was written in MAD and FAP for the CTSS operating system by Jerome E.
+Saltzer in 1964.
+Doug McIlroy rewrote it in BCPL in 1969, renaming it
+.Nm .
+Dennis M. Ritchie rewrote McIlroy's
+.Nm
+in PDP-11 assembly for
+.At v1 ,
+Joseph F. Ossanna improved roff and renamed it nroff
+for
+.At v2 ,
+then ported nroff to C as troff, which Brian W. Kernighan released with
+.At v7 .
+In 1989, James Clarke re-implemented troff in C++, naming it groff.

 .Sh AUTHORS
 .An -nosplit
 .Sh AUTHORS
 .An -nosplit

-This partial
+This

 .Nm
 reference was written by
 .Nm
 reference was written by

-.An Kristaps Dzonsons Aq kristaps@bsd.lv
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv

 and
 and

-.An Ingo Schwarze Aq schwarze@openbsd.org .
+.An Ingo Schwarze Aq Mt schwarze@openbsd.org .