Annotation of mandoc/roff.7, Revision 1.48
1.48 ! schwarze 1: .\" $Id: roff.7,v 1.47 2014/02/14 23:50:57 schwarze Exp $
1.1 kristaps 2: .\"
1.46 schwarze 3: .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
1.47 schwarze 4: .\" Copyright (c) 2010, 2011, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
1.1 kristaps 5: .\"
6: .\" Permission to use, copy, modify, and distribute this software for any
7: .\" purpose with or without fee is hereby granted, provided that the above
8: .\" copyright notice and this permission notice appear in all copies.
9: .\"
10: .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11: .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12: .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13: .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15: .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16: .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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1.48 ! schwarze 18: .Dd $Mdocdate: February 14 2014 $
1.1 kristaps 19: .Dt ROFF 7
20: .Os
21: .Sh NAME
22: .Nm roff
1.17 schwarze 23: .Nd roff language reference for mandoc
1.1 kristaps 24: .Sh DESCRIPTION
25: The
26: .Nm roff
1.17 schwarze 27: language is a general purpose text formatting language.
1.33 schwarze 28: Since traditional implementations of the
1.17 schwarze 29: .Xr mdoc 7
30: and
31: .Xr man 7
1.33 schwarze 32: manual formatting languages are based on it,
33: many real-world manuals use small numbers of
1.17 schwarze 34: .Nm
1.46 schwarze 35: requests and escape sequences intermixed with their
1.33 schwarze 36: .Xr mdoc 7
37: or
38: .Xr man 7
39: code.
40: To properly format such manuals, the
1.1 kristaps 41: .Xr mandoc 1
1.33 schwarze 42: utility supports a tiny subset of
43: .Nm
1.46 schwarze 44: requests and escapes.
45: Only these requests and escapes supported by
1.33 schwarze 46: .Xr mandoc 1
47: are documented in the present manual,
48: together with the basic language syntax shared by
49: .Nm ,
50: .Xr mdoc 7 ,
51: and
52: .Xr man 7 .
53: For complete
54: .Nm
55: manuals, consult the
56: .Sx SEE ALSO
57: section.
1.1 kristaps 58: .Pp
1.33 schwarze 59: Input lines beginning with the control character
1.17 schwarze 60: .Sq \&.
1.33 schwarze 61: are parsed for requests and macros.
62: Such lines are called
63: .Dq request lines
1.1 kristaps 64: or
1.33 schwarze 65: .Dq macro lines ,
66: respectively.
67: Requests change the processing state and manipulate the formatting;
68: some macros also define the document structure and produce formatted
69: output.
70: The single quote
71: .Pq Qq \(aq
72: is accepted as an alternative control character,
73: treated by
74: .Xr mandoc 1
75: just like
76: .Ql \&.
77: .Pp
78: Lines not beginning with control characters are called
79: .Dq text lines .
80: They provide free-form text to be printed; the formatting of the text
81: depends on the respective processing context.
1.1 kristaps 82: .Sh LANGUAGE SYNTAX
83: .Nm
84: documents may contain only graphable 7-bit ASCII characters, the space
1.17 schwarze 85: character, and, in certain circumstances, the tab character.
1.38 kristaps 86: The backslash character
1.33 schwarze 87: .Sq \e
1.46 schwarze 88: indicates the start of an escape sequence, used for example for
1.33 schwarze 89: .Sx Comments ,
90: .Sx Special Characters ,
91: .Sx Predefined Strings ,
92: and
93: user-defined strings defined using the
94: .Sx ds
95: request.
1.46 schwarze 96: For a listing of escape sequences, consult the
97: .Sx ESCAPE SEQUENCE REFERENCE
98: below.
1.33 schwarze 99: .Ss Comments
100: Text following an escaped double-quote
101: .Sq \e\(dq ,
102: whether in a request, macro, or text line, is ignored to the end of the line.
103: A request line beginning with a control character and comment escape
104: .Sq \&.\e\(dq
105: is also ignored.
106: Furthermore, request lines with only a control character and optional
107: trailing whitespace are stripped from input.
108: .Pp
109: Examples:
110: .Bd -literal -offset indent -compact
111: \&.\e\(dq This is a comment line.
112: \&.\e\(dq The next line is ignored:
113: \&.
114: \&.Sh EXAMPLES \e\(dq This is a comment, too.
115: \&example text \e\(dq And so is this.
116: .Ed
117: .Ss Special Characters
118: Special characters are used to encode special glyphs and are rendered
119: differently across output media.
120: They may occur in request, macro, and text lines.
121: Sequences begin with the escape character
122: .Sq \e
123: followed by either an open-parenthesis
124: .Sq \&(
125: for two-character sequences; an open-bracket
126: .Sq \&[
127: for n-character sequences (terminated at a close-bracket
128: .Sq \&] ) ;
129: or a single one character sequence.
130: .Pp
131: Examples:
132: .Bl -tag -width Ds -offset indent -compact
133: .It Li \e(em
134: Two-letter em dash escape.
135: .It Li \ee
136: One-letter backslash escape.
137: .El
138: .Pp
139: See
1.17 schwarze 140: .Xr mandoc_char 7
1.33 schwarze 141: for a complete list.
142: .Ss Text Decoration
143: Terms may be text-decorated using the
144: .Sq \ef
145: escape followed by an indicator: B (bold), I (italic), R (regular), or P
146: (revert to previous mode).
147: A numerical representation 3, 2, or 1 (bold, italic, and regular,
148: respectively) may be used instead.
1.34 kristaps 149: The indicator or numerical representative may be preceded by C
150: (constant-width), which is ignored.
1.33 schwarze 151: .Pp
1.42 schwarze 152: The two-character indicator
153: .Sq BI
154: requests a font that is both bold and italic.
155: It may not be portable to old roff implementations.
156: .Pp
1.33 schwarze 157: Examples:
158: .Bl -tag -width Ds -offset indent -compact
159: .It Li \efBbold\efR
1.42 schwarze 160: Write in \fBbold\fP, then switch to regular font mode.
1.33 schwarze 161: .It Li \efIitalic\efP
1.42 schwarze 162: Write in \fIitalic\fP, then return to previous font mode.
163: .It Li \ef(BIbold italic\efP
164: Write in \f(BIbold italic\fP, then return to previous font mode.
1.33 schwarze 165: .El
166: .Pp
167: Text decoration is
168: .Em not
169: recommended for
170: .Xr mdoc 7 ,
171: which encourages semantic annotation.
172: .Ss Predefined Strings
173: Predefined strings, like
174: .Sx Special Characters ,
175: mark special output glyphs.
176: Predefined strings are escaped with the slash-asterisk,
177: .Sq \e* :
178: single-character
179: .Sq \e*X ,
180: two-character
181: .Sq \e*(XX ,
182: and N-character
183: .Sq \e*[N] .
184: .Pp
185: Examples:
186: .Bl -tag -width Ds -offset indent -compact
187: .It Li \e*(Am
188: Two-letter ampersand predefined string.
189: .It Li \e*q
190: One-letter double-quote predefined string.
191: .El
192: .Pp
193: Predefined strings are not recommended for use,
194: as they differ across implementations.
195: Those supported by
196: .Xr mandoc 1
197: are listed in
198: .Xr mandoc_char 7 .
199: Manuals using these predefined strings are almost certainly not portable.
200: .Ss Whitespace
201: Whitespace consists of the space character.
202: In text lines, whitespace is preserved within a line.
203: In request and macro lines, whitespace delimits arguments and is discarded.
204: .Pp
205: Unescaped trailing spaces are stripped from text line input unless in a
206: literal context.
207: In general, trailing whitespace on any input line is discouraged for
208: reasons of portability.
209: In the rare case that a blank character is needed at the end of an
210: input line, it may be forced by
211: .Sq \e\ \e& .
212: .Pp
213: Literal space characters can be produced in the output
214: using escape sequences.
215: In macro lines, they can also be included in arguments using quotation; see
216: .Sx MACRO SYNTAX
217: for details.
218: .Pp
219: Blank text lines, which may include whitespace, are only permitted
220: within literal contexts.
221: If the first character of a text line is a space, that line is printed
222: with a leading newline.
223: .Ss Scaling Widths
224: Many requests and macros support scaled widths for their arguments.
225: The syntax for a scaled width is
226: .Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
227: where a decimal must be preceded or followed by at least one digit.
228: Negative numbers, while accepted, are truncated to zero.
229: .Pp
230: The following scaling units are accepted:
231: .Pp
232: .Bl -tag -width Ds -offset indent -compact
233: .It c
234: centimetre
235: .It i
236: inch
237: .It P
238: pica (~1/6 inch)
239: .It p
240: point (~1/72 inch)
241: .It f
242: synonym for
243: .Sq u
244: .It v
245: default vertical span
246: .It m
247: width of rendered
248: .Sq m
249: .Pq em
250: character
251: .It n
252: width of rendered
253: .Sq n
254: .Pq en
255: character
256: .It u
257: default horizontal span
258: .It M
259: mini-em (~1/100 em)
260: .El
261: .Pp
262: Using anything other than
263: .Sq m ,
264: .Sq n ,
265: .Sq u ,
266: or
267: .Sq v
268: is necessarily non-portable across output media.
269: See
270: .Sx COMPATIBILITY .
271: .Pp
272: If a scaling unit is not provided, the numerical value is interpreted
273: under the default rules of
274: .Sq v
275: for vertical spaces and
276: .Sq u
277: for horizontal ones.
278: .Pp
279: Examples:
280: .Bl -tag -width ".Bl -tag -width 2i" -offset indent -compact
281: .It Li \&.Bl -tag -width 2i
282: two-inch tagged list indentation in
283: .Xr mdoc 7
284: .It Li \&.HP 2i
285: two-inch tagged list indentation in
286: .Xr man 7
287: .It Li \&.sp 2v
288: two vertical spaces
289: .El
290: .Ss Sentence Spacing
291: Each sentence should terminate at the end of an input line.
292: By doing this, a formatter will be able to apply the proper amount of
293: spacing after the end of sentence (unescaped) period, exclamation mark,
294: or question mark followed by zero or more non-sentence closing
295: delimiters
296: .Po
297: .Sq \&) ,
298: .Sq \&] ,
299: .Sq \&' ,
300: .Sq \&"
301: .Pc .
302: .Pp
303: The proper spacing is also intelligently preserved if a sentence ends at
304: the boundary of a macro line.
305: .Pp
306: Examples:
307: .Bd -literal -offset indent -compact
308: Do not end sentences mid-line like this. Instead,
309: end a sentence like this.
310: A macro would end like this:
311: \&.Xr mandoc 1 \&.
312: .Ed
1.17 schwarze 313: .Sh REQUEST SYNTAX
314: A request or macro line consists of:
315: .Pp
316: .Bl -enum -compact
317: .It
318: the control character
319: .Sq \&.
1.1 kristaps 320: or
1.17 schwarze 321: .Sq \(aq
322: at the beginning of the line,
323: .It
324: optionally an arbitrary amount of whitespace,
325: .It
326: the name of the request or the macro, which is one word of arbitrary
327: length, terminated by whitespace,
328: .It
329: and zero or more arguments delimited by whitespace.
330: .El
331: .Pp
332: Thus, the following request lines are all equivalent:
1.1 kristaps 333: .Bd -literal -offset indent
1.17 schwarze 334: \&.ig end
335: \&.ig end
336: \&. ig end
1.1 kristaps 337: .Ed
1.24 schwarze 338: .Sh MACRO SYNTAX
1.33 schwarze 339: Macros are provided by the
340: .Xr mdoc 7
341: and
342: .Xr man 7
343: languages and can be defined by the
1.24 schwarze 344: .Sx \&de
345: request.
346: When called, they follow the same syntax as requests, except that
347: macro arguments may optionally be quoted by enclosing them
348: in double quote characters
349: .Pq Sq \(dq .
1.33 schwarze 350: Quoted text, even if it contains whitespace or would cause
351: a macro invocation when unquoted, is always considered literal text.
352: Inside quoted text, pairs of double quote characters
353: .Pq Sq Qq
354: resolve to single double quote characters.
355: .Pp
1.32 kristaps 356: To be recognised as the beginning of a quoted argument, the opening
1.24 schwarze 357: quote character must be preceded by a space character.
358: A quoted argument extends to the next double quote character that is not
359: part of a pair, or to the end of the input line, whichever comes earlier.
360: Leaving out the terminating double quote character at the end of the line
361: is discouraged.
362: For clarity, if more arguments follow on the same input line,
363: it is recommended to follow the terminating double quote character
364: by a space character; in case the next character after the terminating
365: double quote character is anything else, it is regarded as the beginning
366: of the next, unquoted argument.
367: .Pp
368: Both in quoted and unquoted arguments, pairs of backslashes
369: .Pq Sq \e\e
370: resolve to single backslashes.
371: In unquoted arguments, space characters can alternatively be included
372: by preceding them with a backslash
373: .Pq Sq \e\~ ,
374: but quoting is usually better for clarity.
1.33 schwarze 375: .Pp
376: Examples:
377: .Bl -tag -width Ds -offset indent -compact
378: .It Li .Fn strlen \(dqconst char *s\(dq
379: Group arguments
380: .Qq const char *s
381: into one function argument.
382: If unspecified,
383: .Qq const ,
384: .Qq char ,
385: and
386: .Qq *s
387: would be considered separate arguments.
388: .It Li .Op \(dqFl a\(dq
389: Consider
390: .Qq \&Fl a
391: as literal text instead of a flag macro.
392: .El
1.15 kristaps 393: .Sh REQUEST REFERENCE
1.17 schwarze 394: The
1.15 kristaps 395: .Xr mandoc 1
396: .Nm
1.32 kristaps 397: parser recognises the following requests.
1.17 schwarze 398: Note that the
1.15 kristaps 399: .Nm
1.17 schwarze 400: language defines many more requests not implemented in
1.15 kristaps 401: .Xr mandoc 1 .
402: .Ss \&ad
403: Set line adjustment mode.
404: This line-scoped request is intended to have one argument to select
1.32 kristaps 405: normal, left, right, or centre adjustment for subsequent text.
1.15 kristaps 406: Currently, it is ignored including its arguments,
407: and the number of arguments is not checked.
1.3 kristaps 408: .Ss \&am
1.15 kristaps 409: Append to a macro definition.
410: The syntax of this request is the same as that of
411: .Sx \&de .
412: It is currently ignored by
413: .Xr mandoc 1 ,
414: as are its children.
1.3 kristaps 415: .Ss \&ami
1.15 kristaps 416: Append to a macro definition, specifying the macro name indirectly.
417: The syntax of this request is the same as that of
418: .Sx \&dei .
419: It is currently ignored by
420: .Xr mandoc 1 ,
421: as are its children.
1.3 kristaps 422: .Ss \&am1
1.15 kristaps 423: Append to a macro definition, switching roff compatibility mode off
424: during macro execution.
425: The syntax of this request is the same as that of
426: .Sx \&de1 .
427: It is currently ignored by
428: .Xr mandoc 1 ,
429: as are its children.
1.47 schwarze 430: .Ss \&as
431: Append to a user-defined string.
432: The syntax of this request is the same as that of
433: .Sx \&ds .
434: If a user-defined string with the specified name does not yet exist,
435: it is set to the empty string before appending.
1.39 kristaps 436: .Ss \&cc
437: Changes the control character.
438: Its syntax is as follows:
439: .Bd -literal -offset indent
440: .Pf . Cm \&cc Op Ar c
441: .Ed
442: .Pp
443: If
444: .Ar c
445: is not specified, the control character is reset to
446: .Sq \&. .
447: Trailing characters are ignored.
1.47 schwarze 448: .Ss \&ce
449: Center some lines.
450: This line-scoped request is intended to take one integer argument,
451: specifying how many lines to center.
452: Currently, it is ignored including its arguments, and the number
453: of arguments is not checked.
1.3 kristaps 454: .Ss \&de
1.17 schwarze 455: Define a
1.15 kristaps 456: .Nm
457: macro.
458: Its syntax can be either
459: .Bd -literal -offset indent
460: .Pf . Cm \&de Ar name
461: .Ar macro definition
462: \&..
463: .Ed
464: .Pp
465: or
466: .Bd -literal -offset indent
467: .Pf . Cm \&de Ar name Ar end
468: .Ar macro definition
469: .Pf . Ar end
470: .Ed
471: .Pp
472: Both forms define or redefine the macro
473: .Ar name
474: to represent the
475: .Ar macro definition ,
476: which may consist of one or more input lines, including the newline
477: characters terminating each line, optionally containing calls to
478: .Nm
479: requests,
480: .Nm
481: macros or high-level macros like
482: .Xr man 7
483: or
484: .Xr mdoc 7
485: macros, whichever applies to the document in question.
486: .Pp
487: Specifying a custom
488: .Ar end
489: macro works in the same way as for
490: .Sx \&ig ;
491: namely, the call to
492: .Sq Pf . Ar end
493: first ends the
494: .Ar macro definition ,
495: and after that, it is also evaluated as a
496: .Nm
497: request or
498: .Nm
499: macro, but not as a high-level macro.
500: .Pp
1.17 schwarze 501: The macro can be invoked later using the syntax
1.15 kristaps 502: .Pp
503: .D1 Pf . Ar name Op Ar argument Op Ar argument ...
504: .Pp
1.24 schwarze 505: Regarding argument parsing, see
506: .Sx MACRO SYNTAX
507: above.
1.15 kristaps 508: .Pp
1.17 schwarze 509: The line invoking the macro will be replaced
1.15 kristaps 510: in the input stream by the
511: .Ar macro definition ,
512: replacing all occurrences of
513: .No \e\e$ Ns Ar N ,
1.17 schwarze 514: where
1.15 kristaps 515: .Ar N
516: is a digit, by the
517: .Ar N Ns th Ar argument .
518: For example,
519: .Bd -literal -offset indent
520: \&.de ZN
521: \efI\e^\e\e$1\e^\efP\e\e$2
522: \&..
523: \&.ZN XtFree .
524: .Ed
525: .Pp
526: produces
527: .Pp
528: .D1 \efI\e^XtFree\e^\efP.
529: .Pp
530: in the input stream, and thus in the output: \fI\^XtFree\^\fP.
531: .Pp
1.17 schwarze 532: Since macros and user-defined strings share a common string table,
1.15 kristaps 533: defining a macro
534: .Ar name
535: clobbers the user-defined string
536: .Ar name ,
537: and the
538: .Ar macro definition
539: can also be printed using the
540: .Sq \e*
541: string interpolation syntax described below
542: .Sx ds ,
543: but this is rarely useful because every macro definition contains at least
544: one explicit newline character.
1.16 schwarze 545: .Pp
546: In order to prevent endless recursion, both groff and
547: .Xr mandoc 1
548: limit the stack depth for expanding macros and strings
549: to a large, but finite number.
550: Do not rely on the exact value of this limit.
1.3 kristaps 551: .Ss \&dei
1.17 schwarze 552: Define a
1.15 kristaps 553: .Nm
554: macro, specifying the macro name indirectly.
1.17 schwarze 555: The syntax of this request is the same as that of
1.15 kristaps 556: .Sx \&de .
557: It is currently ignored by
558: .Xr mandoc 1 ,
559: as are its children.
560: .Ss \&de1
1.17 schwarze 561: Define a
1.15 kristaps 562: .Nm
563: macro that will be executed with
564: .Nm
565: compatibility mode switched off during macro execution.
566: This is a GNU extension not available in traditional
567: .Nm
568: implementations and not even in older versions of groff.
569: Since
570: .Xr mandoc 1
571: does not implement
572: .Nm
1.17 schwarze 573: compatibility mode at all, it handles this request as an alias for
1.15 kristaps 574: .Sx \&de .
1.6 schwarze 575: .Ss \&ds
1.15 kristaps 576: Define a user-defined string.
1.13 kristaps 577: Its syntax is as follows:
578: .Pp
1.15 kristaps 579: .D1 Pf . Cm \&ds Ar name Oo \(dq Oc Ns Ar string
1.13 kristaps 580: .Pp
581: The
1.15 kristaps 582: .Ar name
1.13 kristaps 583: and
1.15 kristaps 584: .Ar string
585: arguments are space-separated.
586: If the
587: .Ar string
588: begins with a double-quote character, that character will not be part
589: of the string.
590: All remaining characters on the input line form the
591: .Ar string ,
592: including whitespace and double-quote characters, even trailing ones.
593: .Pp
1.13 kristaps 594: The
1.15 kristaps 595: .Ar string
596: can be interpolated into subsequent text by using
597: .No \e* Ns Bq Ar name
598: for a
599: .Ar name
600: of arbitrary length, or \e*(NN or \e*N if the length of
601: .Ar name
602: is two or one characters, respectively.
1.17 schwarze 603: Interpolation can be prevented by escaping the leading backslash;
604: that is, an asterisk preceded by an even number of backslashes
605: does not trigger string interpolation.
1.15 kristaps 606: .Pp
607: Since user-defined strings and macros share a common string table,
608: defining a string
609: .Ar name
1.17 schwarze 610: clobbers the macro
1.15 kristaps 611: .Ar name ,
612: and the
613: .Ar name
614: used for defining a string can also be invoked as a macro,
615: in which case the following input line will be appended to the
616: .Ar string ,
617: forming a new input line passed to the
618: .Nm
619: parser.
620: For example,
621: .Bd -literal -offset indent
622: \&.ds badidea .S
623: \&.badidea
624: H SYNOPSIS
625: .Ed
626: .Pp
627: invokes the
628: .Cm SH
629: macro when used in a
630: .Xr man 7
631: document.
632: Such abuse is of course strongly discouraged.
1.5 kristaps 633: .Ss \&el
634: The
635: .Qq else
636: half of an if/else conditional.
637: Pops a result off the stack of conditional evaluations pushed by
638: .Sx \&ie
639: and uses it as its conditional.
640: If no stack entries are present (e.g., due to no prior
641: .Sx \&ie
642: calls)
643: then false is assumed.
1.17 schwarze 644: The syntax of this request is similar to
1.5 kristaps 645: .Sx \&if
646: except that the conditional is missing.
1.27 kristaps 647: .Ss \&EN
648: End an equation block.
649: See
650: .Sx \&EQ .
651: .Ss \&EQ
652: Begin an equation block.
653: See
654: .Xr eqn 7
655: for a description of the equation language.
1.43 schwarze 656: .Ss \&fam
657: Change the font family.
658: This line-scoped request is intended to have one argument specifying
659: the font family to be selected.
660: It is a groff extension, and currently, it is ignored including its
661: arguments, and the number of arguments is not checked.
1.44 schwarze 662: .Ss \&hw
663: Specify hyphenation points in words.
664: This line-scoped request is currently ignored.
1.15 kristaps 665: .Ss \&hy
666: Set automatic hyphenation mode.
667: This line-scoped request is currently ignored.
1.5 kristaps 668: .Ss \&ie
669: The
670: .Qq if
671: half of an if/else conditional.
672: The result of the conditional is pushed into a stack used by subsequent
673: invocations of
674: .Sx \&el ,
675: which may be separated by any intervening input (or not exist at all).
676: Its syntax is equivalent to
677: .Sx \&if .
1.1 kristaps 678: .Ss \&if
1.7 schwarze 679: Begins a conditional.
1.48 ! schwarze 680: This request has the following syntax:
! 681: .Bd -literal -offset indent
! 682: \&.if COND BODY
! 683: .Ed
! 684: .Bd -literal -offset indent
! 685: \&.if COND \e{BODY
! 686: BODY...\e}
! 687: .Ed
! 688: .Bd -literal -offset indent
! 689: \&.if COND \e{\e
! 690: BODY...
! 691: \&.\e}
! 692: .Ed
! 693: .Pp
! 694: COND is a conditional statement.
! 695: Currently,
! 696: .Xr mandoc 1
! 697: supports the following subset of roff conditionals:
! 698: .Bl -bullet
! 699: .It
! 700: If
! 701: .Sq \&!
! 702: is prefixed to COND, the condition is logically inverted.
! 703: .It
! 704: If the first character of COND is
! 705: .Sq n
! 706: .Pq nroff mode
! 707: or
! 708: .Sq o
! 709: .Pq odd page ,
! 710: COND evaluates to true.
! 711: .It
! 712: If the first character of COND is
! 713: .Sq c
! 714: .Pq character available ,
! 715: .Sq d
! 716: .Pq string defined ,
! 717: .Sq e
! 718: .Pq even page ,
! 719: .Sq r
! 720: .Pq register accessed ,
! 721: or
! 722: .Sq t
! 723: .Pq troff mode ,
! 724: COND evaluates to false.
! 725: .It
! 726: If COND starts with a digit, optionally prefixed by a minus sign,
! 727: it is evaluated as a numerical expression of the form
! 728: .Ar number operator number ,
! 729: where
! 730: .Ar operator
! 731: is one of
! 732: .Sq < ,
! 733: .Sq <= ,
! 734: .Sq = ,
! 735: .Sq >= ,
! 736: or
! 737: .Sq > .
! 738: .It
! 739: Otherwise, the first character of COND is regarded as a delimiter
! 740: and COND evaluates to true if the string extending from its first
! 741: to its second occurrence is equal to the string extending from its
! 742: second to its third occurrence.
! 743: .It
! 744: If COND cannot be parsed, it evaluates to false.
! 745: .El
! 746: .Pp
1.3 kristaps 747: If a conditional is false, its children are not processed, but are
748: syntactically interpreted to preserve the integrity of the input
749: document.
750: Thus,
751: .Pp
1.17 schwarze 752: .D1 \&.if t .ig
1.3 kristaps 753: .Pp
754: will discard the
755: .Sq \&.ig ,
756: which may lead to interesting results, but
757: .Pp
1.17 schwarze 758: .D1 \&.if t .if t \e{\e
1.3 kristaps 759: .Pp
760: will continue to syntactically interpret to the block close of the final
761: conditional.
762: Sub-conditionals, in this case, obviously inherit the truth value of
763: the parent.
1.1 kristaps 764: .Pp
765: If the BODY section is begun by an escaped brace
766: .Sq \e{ ,
1.48 ! schwarze 767: scope continues until the end of the input line containing the
! 768: matching closing-brace escape sequence
! 769: .Sq \e} .
1.17 schwarze 770: If the BODY is not enclosed in braces, scope continues until
771: the end of the line.
1.1 kristaps 772: If the COND is followed by a BODY on the same line, whether after a
1.17 schwarze 773: brace or not, then requests and macros
1.1 kristaps 774: .Em must
775: begin with a control character.
776: It is generally more intuitive, in this case, to write
777: .Bd -literal -offset indent
778: \&.if COND \e{\e
779: \&.foo
780: bar
781: \&.\e}
782: .Ed
783: .Pp
1.17 schwarze 784: than having the request or macro follow as
1.1 kristaps 785: .Pp
786: .D1 \&.if COND \e{ .foo
787: .Pp
788: The scope of a conditional is always parsed, but only executed if the
789: conditional evaluates to true.
790: .Pp
1.29 kristaps 791: Note that the
1.1 kristaps 792: .Sq \e}
1.29 kristaps 793: is converted into a zero-width escape sequence if not passed as a
794: standalone macro
795: .Sq \&.\e} .
796: For example,
797: .Pp
798: .D1 \&.Fl a \e} b
799: .Pp
800: will result in
1.8 kristaps 801: .Sq \e}
1.29 kristaps 802: being considered an argument of the
803: .Sq \&Fl
804: macro.
1.1 kristaps 805: .Ss \&ig
1.2 kristaps 806: Ignore input.
1.15 kristaps 807: Its syntax can be either
808: .Bd -literal -offset indent
809: .Pf . Cm \&ig
810: .Ar ignored text
1.2 kristaps 811: \&..
812: .Ed
1.15 kristaps 813: .Pp
814: or
815: .Bd -literal -offset indent
816: .Pf . Cm \&ig Ar end
817: .Ar ignored text
818: .Pf . Ar end
1.2 kristaps 819: .Ed
820: .Pp
821: In the first case, input is ignored until a
822: .Sq \&..
1.17 schwarze 823: request is encountered on its own line.
1.15 kristaps 824: In the second case, input is ignored until the specified
825: .Sq Pf . Ar end
826: macro is encountered.
827: Do not use the escape character
1.2 kristaps 828: .Sq \e
1.15 kristaps 829: anywhere in the definition of
830: .Ar end ;
831: it would cause very strange behaviour.
832: .Pp
833: When the
834: .Ar end
835: macro is a roff request or a roff macro, like in
1.2 kristaps 836: .Pp
837: .D1 \&.ig if
838: .Pp
839: the subsequent invocation of
840: .Sx \&if
1.15 kristaps 841: will first terminate the
842: .Ar ignored text ,
843: then be invoked as usual.
844: Otherwise, it only terminates the
845: .Ar ignored text ,
846: and arguments following it or the
847: .Sq \&..
1.17 schwarze 848: request are discarded.
1.15 kristaps 849: .Ss \&ne
850: Declare the need for the specified minimum vertical space
851: before the next trap or the bottom of the page.
852: This line-scoped request is currently ignored.
853: .Ss \&nh
854: Turn off automatic hyphenation mode.
855: This line-scoped request is currently ignored.
1.6 schwarze 856: .Ss \&rm
857: Remove a request, macro or string.
1.15 kristaps 858: This request is intended to have one argument,
1.6 schwarze 859: the name of the request, macro or string to be undefined.
860: Currently, it is ignored including its arguments,
861: and the number of arguments is not checked.
1.10 kristaps 862: .Ss \&nr
1.45 schwarze 863: Define or change a register.
1.10 kristaps 864: A register is an arbitrary string value that defines some sort of state,
865: which influences parsing and/or formatting.
866: Its syntax is as follows:
867: .Pp
1.45 schwarze 868: .D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar value
1.10 kristaps 869: .Pp
870: The
1.15 kristaps 871: .Ar value
1.10 kristaps 872: may, at the moment, only be an integer.
1.46 schwarze 873: If it is prefixed by a sign, the register will be
1.45 schwarze 874: incremented or decremented instead of assigned to.
875: .Pp
876: The following register
1.15 kristaps 877: .Ar name
1.45 schwarze 878: is handled specially:
1.10 kristaps 879: .Bl -tag -width Ds
880: .It Cm nS
881: If set to a positive integer value, certain
882: .Xr mdoc 7
1.17 schwarze 883: macros will behave in the same way as in the
1.10 kristaps 884: .Em SYNOPSIS
1.11 kristaps 885: section.
1.17 schwarze 886: If set to 0, these macros will behave in the same way as outside the
887: .Em SYNOPSIS
888: section, even when called within the
1.10 kristaps 889: .Em SYNOPSIS
1.17 schwarze 890: section itself.
891: Note that starting a new
1.11 kristaps 892: .Xr mdoc 7
1.17 schwarze 893: section with the
894: .Cm \&Sh
895: macro will reset this register.
1.10 kristaps 896: .El
1.26 schwarze 897: .Ss \&ns
898: Turn on no-space mode.
899: This line-scoped request is intended to take no arguments.
900: Currently, it is ignored including its arguments,
901: and the number of arguments is not checked.
902: .Ss \&ps
903: Change point size.
904: This line-scoped request is intended to take one numerical argument.
905: Currently, it is ignored including its arguments,
906: and the number of arguments is not checked.
1.15 kristaps 907: .Ss \&so
908: Include a source file.
909: Its syntax is as follows:
910: .Pp
911: .D1 Pf \. Cm \&so Ar file
912: .Pp
913: The
914: .Ar file
915: will be read and its contents processed as input in place of the
916: .Sq \&.so
917: request line.
1.28 kristaps 918: To avoid inadvertent inclusion of unrelated files,
1.15 kristaps 919: .Xr mandoc 1
920: only accepts relative paths not containing the strings
921: .Qq ../
922: and
923: .Qq /.. .
1.37 schwarze 924: .Pp
925: This request requires
926: .Xr man 1
927: to change to the right directory before calling
928: .Xr mandoc 1 ,
929: per convention to the root of the manual tree.
930: Typical usage looks like:
931: .Pp
932: .Dl \&.so man3/Xcursor.3
933: .Pp
934: As the whole concept is rather fragile, the use of
935: .Sx \&so
936: is discouraged.
937: Use
938: .Xr ln 1
939: instead.
1.26 schwarze 940: .Ss \&ta
941: Set tab stops.
942: This line-scoped request can take an arbitrary number of arguments.
943: Currently, it is ignored including its arguments.
1.6 schwarze 944: .Ss \&tr
945: Output character translation.
1.30 kristaps 946: Its syntax is as follows:
947: .Pp
948: .D1 Pf \. Cm \&tr Ar [ab]+
949: .Pp
950: Pairs of
951: .Ar ab
952: characters are replaced
953: .Ar ( a
954: for
955: .Ar b ) .
956: Replacement (or origin) characters may also be character escapes; thus,
957: .Pp
958: .Dl tr \e(xx\e(yy
959: .Pp
960: replaces all invocations of \e(xx with \e(yy.
1.20 kristaps 961: .Ss \&T&
962: Re-start a table layout, retaining the options of the prior table
963: invocation.
964: See
965: .Sx \&TS .
966: .Ss \&TE
967: End a table context.
968: See
969: .Sx \&TS .
970: .Ss \&TS
971: Begin a table, which formats input in aligned rows and columns.
1.23 kristaps 972: See
973: .Xr tbl 7
974: for a description of the tbl language.
1.46 schwarze 975: .Sh ESCAPE SEQUENCE REFERENCE
976: The
977: .Xr mandoc 1
978: .Nm
979: parser recognises the following escape sequences.
980: Note that the
981: .Nm
982: language defines more escape sequences not implemented in
983: .Xr mandoc 1 .
984: In
985: .Xr mdoc 7
986: and
987: .Xr man 7
988: documents, using escape sequences is discouraged except for those
989: described in the
990: .Sx LANGUAGE SYNTAX
991: section above.
992: .Pp
993: A backslash followed by any character not listed here
994: simply prints that character itself.
995: .Ss \e<newline>
996: A backslash at the end of an input line can be used to continue the
997: logical input line on the next physical input line, joining the text
998: on both lines together as if it were on a single input line.
999: .Ss \e<space>
1000: The escape sequence backslash-space
1001: .Pq Sq \e\ \&
1002: is an unpaddable space-sized non-breaking space character; see
1003: .Sx Whitespace .
1004: .Ss \e\(dq
1005: The rest of the input line is treated as
1006: .Sx Comments .
1007: .Ss \e%
1008: Hyphenation allowed at this point of the word; ignored by
1009: .Xr mandoc 1 .
1010: .Ss \e&
1011: Non-printing zero-width character; see
1012: .Sx Whitespace .
1013: .Ss \e\(aq
1014: Acute accent special character; use
1015: .Sq \e(aa
1016: instead.
1017: .Ss \e( Ns Ar cc
1018: .Sx Special Characters
1019: with two-letter names, see
1020: .Xr mandoc_char 7 .
1021: .Ss \e*[ Ns Ar name ]
1022: Interpolate the string with the
1023: .Ar name ;
1024: see
1025: .Sx Predefined Strings
1026: and
1027: .Sx ds .
1028: For short names, there are variants
1029: .No \e* Ns Ar c
1030: and
1031: .No \e*( Ns Ar cc .
1032: .Ss \e-
1033: Special character
1034: .Dq mathematical minus sign .
1035: .Ss \e[ Ns Ar name ]
1036: .Sx Special Characters
1037: with names of arbitrary length, see
1038: .Xr mandoc_char 7 .
1039: .Ss \e^
1040: One-twelfth em half-narrow space character, effectively zero-width in
1041: .Xr mandoc 1 .
1042: .Ss \e`
1043: Grave accent special character; use
1044: .Sq \e(ga
1045: instead.
1046: .Ss \e{
1047: Begin conditional input; see
1048: .Sx if .
1049: .Ss \e\(ba
1050: One-sixth em narrow space character, effectively zero-width in
1051: .Xr mandoc 1 .
1052: .Ss \e}
1053: End conditional input; see
1054: .Sx if .
1055: .Ss \e~
1056: Paddable non-breaking space character.
1057: .Ss \e0
1058: Digit width space character.
1059: .Ss \eA\(aq Ns Ar string Ns \(aq
1060: Anchor definition; ignored by
1061: .Xr mandoc 1 .
1062: .Ss \eB\(aq Ns Ar string Ns \(aq
1063: Test whether
1064: .Ar string
1065: is a numerical expession; ignored by
1066: .Xr mandoc 1 .
1067: .Ss \eb\(aq Ns Ar string Ns \(aq
1068: Bracket building function; ignored by
1069: .Xr mandoc 1 .
1070: .Ss \eC\(aq Ns Ar name Ns \(aq
1071: .Sx Special Characters
1072: with names of arbitrary length.
1073: .Ss \ec
1074: Interrupt text processing to insert requests or macros; ignored by
1075: .Xr mandoc 1 .
1076: .Ss \eD\(aq Ns Ar string Ns \(aq
1077: Draw graphics function; ignored by
1078: .Xr mandoc 1 .
1079: .Ss \ed
1080: Move down by half a line; ignored by
1081: .Xr mandoc 1 .
1082: .Ss \ee
1083: Backslash special character.
1084: .Ss \eF[ Ns Ar name ]
1085: Switch font family (groff extension); ignored by
1086: .Xr mandoc 1 .
1087: For short names, there are variants
1088: .No \eF Ns Ar c
1089: and
1090: .No \eF( Ns Ar cc .
1091: .Ss \ef[ Ns Ar name ]
1092: Switch to the font
1093: .Ar name ,
1094: see
1095: .Sx Text Decoration .
1096: For short names, there are variants
1097: .No \ef Ns Ar c
1098: and
1099: .No \ef( Ns Ar cc .
1100: .Ss \eg[ Ns Ar name ]
1101: Interpolate the format of a number register; ignored by
1102: .Xr mandoc 1 .
1103: For short names, there are variants
1104: .No \eg Ns Ar c
1105: and
1106: .No \eg( Ns Ar cc .
1107: .Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
1108: Set the height of the current font; ignored by
1109: .Xr mandoc 1 .
1110: .Ss \eh\(aq Ns Ar number Ns \(aq
1111: Horizontal motion; ignored by
1112: .Xr mandoc 1 .
1113: .Ss \ek[ Ns Ar name ]
1114: Mark horizontal input place in register; ignored by
1115: .Xr mandoc 1 .
1116: For short names, there are variants
1117: .No \ek Ns Ar c
1118: and
1119: .No \ek( Ns Ar cc .
1120: .Ss \eL\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
1121: Vertical line drawing function; ignored by
1122: .Xr mandoc 1 .
1123: .Ss \el\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
1124: Horizontal line drawing function; ignored by
1125: .Xr mandoc 1 .
1126: .Ss \eM[ Ns Ar name ]
1127: Set fill (background) color (groff extension); ignored by
1128: .Xr mandoc 1 .
1129: For short names, there are variants
1130: .No \eM Ns Ar c
1131: and
1132: .No \eM( Ns Ar cc .
1133: .Ss \em[ Ns Ar name ]
1134: Set glyph drawing color (groff extension); ignored by
1135: .Xr mandoc 1 .
1136: For short names, there are variants
1137: .No \em Ns Ar c
1138: and
1139: .No \em( Ns Ar cc .
1140: .Ss \eN\(aq Ns Ar number Ns \(aq
1141: Character
1142: .Ar number
1143: on the current font.
1144: .Ss \en[ Ns Ar name ]
1145: Interpolate the number register
1146: .Ar name .
1147: For short names, there are variants
1148: .No \en Ns Ar c
1149: and
1150: .No \en( Ns Ar cc .
1151: .Ss \eo\(aq Ns Ar string Ns \(aq
1152: Overstrike
1153: .Ar string ;
1154: ignored by
1155: .Xr mandoc 1 .
1156: .Ss \eR\(aq Ns Ar name Oo +|- Oc Ns Ar number Ns \(aq
1157: Set number register; ignored by
1158: .Xr mandoc 1 .
1159: .Ss \eS\(aq Ns Ar number Ns \(aq
1160: Slant output; ignored by
1161: .Xr mandoc 1 .
1162: .Ss \es\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
1163: Change point size; ignored by
1164: .Xr mandoc 1 .
1165: Alternative forms
1166: .No \es Ns Oo +|- Oc Ns Ar n ,
1167: .No \es Ns Oo +|- Oc Ns \(aq Ns Ar number Ns \(aq ,
1168: .No \es Ns [ Oo +|- Oc Ns Ar number ] ,
1169: and
1170: .No \es Ns Oo +|- Oc Ns [ Ar number Ns ]
1171: are also parsed and ignored.
1172: .Ss \et
1173: Horizontal tab; ignored by
1174: .Xr mandoc 1 .
1175: .Ss \eu
1176: Move up by half a line; ignored by
1177: .Xr mandoc 1 .
1178: .Ss \eV[ Ns Ar name ]
1179: Interpolate an environment variable; ignored by
1180: .Xr mandoc 1 .
1181: For short names, there are variants
1182: .No \eV Ns Ar c
1183: and
1184: .No \eV( Ns Ar cc .
1185: .Ss \ev\(aq Ns Ar number Ns \(aq
1186: Vertical motion; ignored by
1187: .Xr mandoc 1 .
1188: .Ss \ew\(aq Ns Ar string Ns \(aq
1189: Interpolate the width of the
1190: .Ar string ;
1191: ignored by
1192: .Xr mandoc 1 .
1193: .Ss \eX\(aq Ns Ar string Ns \(aq
1194: Output
1195: .Ar string
1196: as device control function; ignored in nroff mode and by
1197: .Xr mandoc 1 .
1198: .Ss \ex\(aq Ns Ar number Ns \(aq
1199: Extra line space function; ignored by
1200: .Xr mandoc 1 .
1201: .Ss \eY[ Ns Ar name ]
1202: Output a string as a device control function; ignored in nroff mode and by
1203: .Xr mandoc 1 .
1204: For short names, there are variants
1205: .No \eY Ns Ar c
1206: and
1207: .No \eY( Ns Ar cc .
1208: .Ss \eZ\(aq Ns Ar string Ns \(aq
1209: Print
1210: .Ar string
1211: with zero width and height; ignored by
1212: .Xr mandoc 1 .
1213: .Ss \ez
1214: Output the next character without advancing the cursor position;
1215: approximated in
1216: .Xr mandoc 1
1217: by simply skipping the next character.
1.2 kristaps 1218: .Sh COMPATIBILITY
1.40 schwarze 1219: This section documents compatibility between mandoc and other
1.17 schwarze 1220: .Nm
1221: implementations, at this time limited to GNU troff
1.2 kristaps 1222: .Pq Qq groff .
1223: The term
1224: .Qq historic groff
1.17 schwarze 1225: refers to groff version 1.15.
1.2 kristaps 1226: .Pp
1227: .Bl -dash -compact
1.10 kristaps 1228: .It
1.27 kristaps 1229: In mandoc, the
1230: .Sx \&EQ ,
1231: .Sx \&TE ,
1232: .Sx \&TS ,
1233: and
1234: .Sx \&T& ,
1235: macros are considered regular macros.
1236: In all other
1237: .Nm
1238: implementations, these are special macros that must be specified without
1239: spacing between the control character (which must be a period) and the
1240: macro name.
1241: .It
1.10 kristaps 1242: The
1243: .Cm nS
1.17 schwarze 1244: register is only compatible with OpenBSD's groff-1.15.
1.2 kristaps 1245: .It
1.17 schwarze 1246: Historic groff did not accept white-space before a custom
1247: .Ar end
1248: macro for the
1.2 kristaps 1249: .Sx \&ig
1.17 schwarze 1250: request.
1.4 kristaps 1251: .It
1252: The
1253: .Sx \&if
1254: and family would print funny white-spaces with historic groff when
1.17 schwarze 1255: using the next-line syntax.
1.2 kristaps 1256: .El
1.17 schwarze 1257: .Sh SEE ALSO
1258: .Xr mandoc 1 ,
1.27 kristaps 1259: .Xr eqn 7 ,
1.17 schwarze 1260: .Xr man 7 ,
1261: .Xr mandoc_char 7 ,
1.23 kristaps 1262: .Xr mdoc 7 ,
1263: .Xr tbl 7
1.17 schwarze 1264: .Rs
1265: .%A Joseph F. Ossanna
1266: .%A Brian W. Kernighan
1267: .%I AT&T Bell Laboratories
1268: .%T Troff User's Manual
1269: .%R Computing Science Technical Report
1270: .%N 54
1271: .%C Murray Hill, New Jersey
1272: .%D 1976 and 1992
1273: .%U http://www.kohala.com/start/troff/cstr54.ps
1274: .Re
1275: .Rs
1276: .%A Joseph F. Ossanna
1277: .%A Brian W. Kernighan
1278: .%A Gunnar Ritter
1279: .%T Heirloom Documentation Tools Nroff/Troff User's Manual
1280: .%D September 17, 2007
1281: .%U http://heirloom.sourceforge.net/doctools/troff.pdf
1282: .Re
1283: .Sh HISTORY
1.35 kristaps 1284: The RUNOFF typesetting system, whose input forms the basis for
1.17 schwarze 1285: .Nm ,
1.35 kristaps 1286: was written in MAD and FAP for the CTSS operating system by Jerome E.
1287: Saltzer in 1964.
1288: Doug McIlroy rewrote it in BCPL in 1969, renaming it
1289: .Nm .
1290: Dennis M. Ritchie rewrote McIlroy's
1.36 schwarze 1291: .Nm
1292: in PDP-11 assembly for
1.35 kristaps 1293: .At v1 ,
1294: Joseph F. Ossanna improved roff and renamed it nroff
1295: for
1296: .At v2 ,
1297: then ported nroff to C as troff, which Brian W. Kernighan released with
1298: .At v7 .
1299: In 1989, James Clarke re-implemented troff in C++, naming it groff.
1.1 kristaps 1300: .Sh AUTHORS
1.15 kristaps 1301: .An -nosplit
1.31 kristaps 1302: This
1.1 kristaps 1303: .Nm
1304: reference was written by
1.41 schwarze 1305: .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
1.15 kristaps 1306: and
1.41 schwarze 1307: .An Ingo Schwarze Aq Mt schwarze@openbsd.org .
CVSweb