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diff --git a/contrib/mdocml/roff.7 b/contrib/mdocml/roff.7 new file mode 100644 index 0000000..bc2f24e --- /dev/null +++ b/contrib/mdocml/roff.7 @@ -0,0 +1,1429 @@ +.\" $Id: roff.7,v 1.55 2014/07/07 11:35:06 schwarze Exp $ +.\" +.\" 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 +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.Dd $Mdocdate: July 7 2014 $ +.Dt ROFF 7 +.Os +.Sh NAME +.Nm roff +.Nd roff language reference for mandoc +.Sh DESCRIPTION +The +.Nm roff +language is a general purpose text formatting language. +Since traditional implementations of the +.Xr mdoc 7 +and +.Xr man 7 +manual formatting languages are based on it, +many real-world manuals use small numbers of +.Nm +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 +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 +Input lines beginning with the control character +.Sq \&. +are parsed for requests and macros. +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. +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 +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 +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 +.Bl -enum -compact +.It +the control character +.Sq \&. +or +.Sq \(aq +at the beginning of the line, +.It +optionally an arbitrary amount of whitespace, +.It +the name of the request or the macro, which is one word of arbitrary +length, terminated by whitespace, +.It +and zero or more arguments delimited by whitespace. +.El +.Pp +Thus, the following request lines are all equivalent: +.Bd -literal -offset indent +\&.ig end +\&.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 +parser recognises the following requests. +Note that the +.Nm +language defines many more requests not implemented in +.Xr mandoc 1 . +.Ss \&ad +Set line adjustment mode. +This line-scoped request is intended to have one argument to select +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 +Append to a macro definition. +The syntax of this request is the same as that of +.Sx \&de . +.Ss \&ami +Append to a macro definition, specifying the macro name indirectly. +The syntax of this request is the same as that of +.Sx \&dei . +.Ss \&am1 +Append to a macro definition, switching roff compatibility mode off +during macro execution. +The syntax of this request is the same as that of +.Sx \&de1 . +Since +.Xr mandoc 1 +does not implement +.Nm +compatibility mode at all, it handles this request as an alias for +.Sx \&am . +.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 +macro. +Its syntax can be either +.Bd -literal -offset indent +.Pf . Cm \&de Ar name +.Ar macro definition +\&.. +.Ed +.Pp +or +.Bd -literal -offset indent +.Pf . Cm \&de Ar name Ar end +.Ar macro definition +.Pf . Ar end +.Ed +.Pp +Both forms define or redefine the macro +.Ar name +to represent the +.Ar macro definition , +which may consist of one or more input lines, including the newline +characters terminating each line, optionally containing calls to +.Nm +requests, +.Nm +macros or high-level macros like +.Xr man 7 +or +.Xr mdoc 7 +macros, whichever applies to the document in question. +.Pp +Specifying a custom +.Ar end +macro works in the same way as for +.Sx \&ig ; +namely, the call to +.Sq Pf . Ar end +first ends the +.Ar macro definition , +and after that, it is also evaluated as a +.Nm +request or +.Nm +macro, but not as a high-level macro. +.Pp +The macro can be invoked later using the syntax +.Pp +.D1 Pf . Ar name Op Ar argument Op Ar argument ... +.Pp +Regarding argument parsing, see +.Sx MACRO SYNTAX +above. +.Pp +The line invoking the macro will be replaced +in the input stream by the +.Ar macro definition , +replacing all occurrences of +.No \e\e$ Ns Ar N , +where +.Ar N +is a digit, by the +.Ar N Ns th Ar argument . +For example, +.Bd -literal -offset indent +\&.de ZN +\efI\e^\e\e$1\e^\efP\e\e$2 +\&.. +\&.ZN XtFree . +.Ed +.Pp +produces +.Pp +.D1 \efI\e^XtFree\e^\efP. +.Pp +in the input stream, and thus in the output: \fI\^XtFree\^\fP. +.Pp +Since macros and user-defined strings share a common string table, +defining a macro +.Ar name +clobbers the user-defined string +.Ar name , +and the +.Ar macro definition +can also be printed using the +.Sq \e* +string interpolation syntax described below +.Sx ds , +but this is rarely useful because every macro definition contains at least +one explicit newline character. +.Pp +In order to prevent endless recursion, both groff and +.Xr mandoc 1 +limit the stack depth for expanding macros and strings +to a large, but finite number. +Do not rely on the exact value of this limit. +.Ss \&dei +Define a +.Nm +macro, specifying the macro name indirectly. +The syntax of this request is the same as that of +.Sx \&de . +The request +.Pp +.D1 Pf . Cm \&dei Ar name Op Ar end +.Pp +has the same effect as: +.Pp +.D1 Pf . Cm \&de No \e* Ns Bo Ar name Bc Op \e* Ns Bq Ar end +.Ss \&de1 +Define a +.Nm +macro that will be executed with +.Nm +compatibility mode switched off during macro execution. +This is a GNU extension not available in traditional +.Nm +implementations and not even in older versions of groff. +Since +.Xr mandoc 1 +does not implement +.Nm +compatibility mode at all, it handles this request as an alias for +.Sx \&de . +.Ss \&ds +Define a user-defined string. +Its syntax is as follows: +.Pp +.D1 Pf . Cm \&ds Ar name Oo \(dq Oc Ns Ar string +.Pp +The +.Ar name +and +.Ar string +arguments are space-separated. +If the +.Ar string +begins with a double-quote character, that character will not be part +of the string. +All remaining characters on the input line form the +.Ar string , +including whitespace and double-quote characters, even trailing ones. +.Pp +The +.Ar string +can be interpolated into subsequent text by using +.No \e* Ns Bq Ar name +for a +.Ar name +of arbitrary length, or \e*(NN or \e*N if the length of +.Ar name +is two or one characters, respectively. +Interpolation can be prevented by escaping the leading backslash; +that is, an asterisk preceded by an even number of backslashes +does not trigger string interpolation. +.Pp +Since user-defined strings and macros share a common string table, +defining a string +.Ar name +clobbers the macro +.Ar name , +and the +.Ar name +used for defining a string can also be invoked as a macro, +in which case the following input line will be appended to the +.Ar string , +forming a new input line passed to the +.Nm +parser. +For example, +.Bd -literal -offset indent +\&.ds badidea .S +\&.badidea +H SYNOPSIS +.Ed +.Pp +invokes the +.Cm SH +macro when used in a +.Xr man 7 +document. +Such abuse is of course strongly discouraged. +.Ss \&el +The +.Qq else +half of an if/else conditional. +Pops a result off the stack of conditional evaluations pushed by +.Sx \&ie +and uses it as its conditional. +If no stack entries are present (e.g., due to no prior +.Sx \&ie +calls) +then false is assumed. +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 \&ie +The +.Qq if +half of an if/else conditional. +The result of the conditional is pushed into a stack used by subsequent +invocations of +.Sx \&el , +which may be separated by any intervening input (or not exist at all). +Its syntax is equivalent to +.Sx \&if . +.Ss \&if +Begins a conditional. +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 parenthesis or with an optionally signed +integer number, it is evaluated according to the rules of +.Sx Numerical expressions +explained below. +It evaluates to true if the the result is positive, +or to false if the result is zero or negative. +.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. +Thus, +.Pp +.D1 \&.if t .ig +.Pp +will discard the +.Sq \&.ig , +which may lead to interesting results, but +.Pp +.D1 \&.if t .if t \e{\e +.Pp +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. +.Pp +If the BODY section is begun by an escaped brace +.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 +brace or not, then requests and macros +.Em must +begin with a control character. +It is generally more intuitive, in this case, to write +.Bd -literal -offset indent +\&.if COND \e{\e +\&.foo +bar +\&.\e} +.Ed +.Pp +than having the request or macro follow as +.Pp +.D1 \&.if COND \e{ .foo +.Pp +The scope of a conditional is always parsed, but only executed if the +conditional evaluates to true. +.Pp +Note that the +.Sq \e} +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} +being considered an argument of the +.Sq \&Fl +macro. +.Ss \&ig +Ignore input. +Its syntax can be either +.Bd -literal -offset indent +.Pf . Cm \&ig +.Ar ignored text +\&.. +.Ed +.Pp +or +.Bd -literal -offset indent +.Pf . Cm \&ig Ar end +.Ar ignored text +.Pf . Ar end +.Ed +.Pp +In the first case, input is ignored until a +.Sq \&.. +request is encountered on its own line. +In the second case, input is ignored until the specified +.Sq Pf . Ar end +macro is encountered. +Do not use the escape character +.Sq \e +anywhere in the definition of +.Ar end ; +it would cause very strange behaviour. +.Pp +When the +.Ar end +macro is a roff request or a roff macro, like in +.Pp +.D1 \&.ig if +.Pp +the subsequent invocation of +.Sx \&if +will first terminate the +.Ar ignored text , +then be invoked as usual. +Otherwise, it only terminates the +.Ar ignored text , +and arguments following it or the +.Sq \&.. +request are discarded. +.Ss \&ll +Change the output line length. +Its syntax is as follows: +.Pp +.D1 Pf . Cm \&ll Op Oo +|- Oc Ns Ar width +.Pp +If the +.Ar width +argument is omitted, the line length is reset to its previous value. +The default setting for terminal output is 78n. +If a sign is given, the line length is added to or subtracted from; +otherwise, it is set to the provided value. +Using this request in new manuals is discouraged for several reasons, +among others because it overrides the +.Xr mandoc 1 +.Fl O Cm width +command line option. +.Ss \&ne +Declare the need for the specified minimum vertical space +before the next trap or the bottom of the page. +This line-scoped request is currently ignored. +.Ss \&nh +Turn off automatic hyphenation mode. +This line-scoped request is currently ignored. +.Ss \&nr +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 +.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar expression +.Pp +For the syntax of +.Ar expression , +see +.Sx Numerical expressions +below. +If it is prefixed by a sign, the register will be +incremented or decremented instead of assigned to. +.Pp +The following register +.Ar name +is handled specially: +.Bl -tag -width Ds +.It Cm nS +If set to a positive integer value, certain +.Xr mdoc 7 +macros will behave in the same way as in the +.Em SYNOPSIS +section. +If set to 0, these macros will behave in the same way as outside the +.Em SYNOPSIS +section, even when called within the +.Em SYNOPSIS +section itself. +Note that starting a new +.Xr mdoc 7 +section with the +.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 \&rm +Remove a request, macro or string. +Its syntax is as follows: +.Pp +.D1 Pf \. Cm \&rm Ar name +.Ss \&rr +Remove a register. +Its syntax is as follows: +.Pp +.D1 Pf \. Cm \&rr Ar name +.Ss \&so +Include a source file. +Its syntax is as follows: +.Pp +.D1 Pf \. Cm \&so Ar file +.Pp +The +.Ar file +will be read and its contents processed as input in place of the +.Sq \&.so +request line. +To avoid inadvertent inclusion of unrelated files, +.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. +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. +See +.Sx \&TS . +.Ss \&TE +End a table context. +See +.Sx \&TS . +.Ss \&TS +Begin a table, which formats input in aligned rows and columns. +See +.Xr tbl 7 +for a description of the tbl language. +.Ss Numerical expressions +The +.Sx \&nr , +.Sx \&if , +and +.Sx \&ie +requests accept integer numerical expressions as arguments. +These are always evaluated using the C +.Vt int +type; integer overflow works the same way as in the C language. +Numbers consist of an arbitrary number of digits +.Sq 0 +to +.Sq 9 +prefixed by an optional sign +.Sq + +or +.Sq - . +.Pp +The following binary operators are implemented. +Unless otherwise stated, they behave as in the C language: +.Pp +.Bl -tag -width 2n -compact +.It Ic + +addition +.It Ic - +subtraction +.It Ic * +multiplication +.It Ic / +division +.It Ic % +remainder of division +.It Ic < +less than +.It Ic > +greater than +.It Ic == +equal to +.It Ic = +equal to, same effect as +.Ic == +(this differs from C) +.It Ic <= +less than or equal to +.It Ic >= +greater than or equal to +.It Ic <> +not equal to (corresponds to C +.Ic != ; +this one is of limited portability, it is supported by Heirloom roff, +but not by groff) +.It Ic & +logical and (corresponds to C +.Ic && ) +.It Ic \&: +logical or (corresponds to C +.Ic \&|| ) +.It Ic <? +minimum (not available in C) +.It Ic >? +maximum (not available in C) +.El +.Pp +There is no concept of precendence; evaluation proceeds from left to right, +except when subexpressions are enclosed in parantheses. +Inside parentheses, whitespace is ignored. +.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 +and +.Xr man 7 +documents, using escape sequences is discouraged except for those +described in the +.Sx LANGUAGE SYNTAX +section above. +.Pp +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 . +.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 +.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 . +.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 +Interpolate +.Sq 1 +if +.Ar string +conforms to the syntax of +.Sx Numerical expressions +explained above and +.Sq 0 +otherwise. +.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 . +The +.Xr mandoc 1 +implementation assumes that after expansion of user-defined strings, the +.Ar string +only contains normal characters, no escape sequences, and that each +character has a width of 24 basic units. +.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 +This section documents compatibility between mandoc and other +.Nm +implementations, at this time limited to GNU troff +.Pq Qq groff . +The term +.Qq historic groff +refers to groff version 1.15. +.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. +.It +Historic groff did not accept white-space before a custom +.Ar end +macro for the +.Sx \&ig +request. +.It +The +.Sx \&if +and family would print funny white-spaces with historic groff when +using the next-line syntax. +.El +.Sh SEE ALSO +.Xr mandoc 1 , +.Xr eqn 7 , +.Xr man 7 , +.Xr mandoc_char 7 , +.Xr mdoc 7 , +.Xr tbl 7 +.Rs +.%A Joseph F. Ossanna +.%A Brian W. Kernighan +.%I AT&T Bell Laboratories +.%T Troff User's Manual +.%R Computing Science Technical Report +.%N 54 +.%C Murray Hill, New Jersey +.%D 1976 and 1992 +.%U http://www.kohala.com/start/troff/cstr54.ps +.Re +.Rs +.%A Joseph F. Ossanna +.%A Brian W. Kernighan +.%A Gunnar Ritter +.%T Heirloom Documentation Tools Nroff/Troff User's Manual +.%D September 17, 2007 +.%U http://heirloom.sourceforge.net/doctools/troff.pdf +.Re +.Sh HISTORY +The RUNOFF typesetting system, whose input forms the basis for +.Nm , +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 +This +.Nm +reference was written by +.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv +and +.An Ingo Schwarze Aq Mt schwarze@openbsd.org . |
